JPH0155846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is equipped with narrow propulsion wheels at the left and right center of the front part of the machine body, and connects a seedling planting device with a plurality of floats arranged in parallel to the rear part of the machine body. A sled body installed at the lower left and right center of the seedling planting device is automatically raised and lowered by a hydraulic cylinder that is controlled based on the ground pressure detection results installed in the seedling planting device, and the sensor ground pressure is maintained within a set range. This is about a rice transplanter.

A rice transplanter with such a configuration has the characteristic that the propulsion wheels at the front of the machine come into contact with the tiller at the center of the left and right sides of the machine, allowing it to move straight without being affected by the left-right inclination of the tiller or the difference in unevenness between the left and right sides. However, there was a problem in that the stability of the aircraft in the left-right direction decreased when the weight on the center sled body became large due to the reduced support of the weight of the aircraft by the floats. For example, if the central sled body suddenly rides on a shallow part of the plowing platform, and the rear of the machine is pushed up,
The weight supporting the aircraft by the floats was reduced, and the weight of the center sled body was increased, which could cause the aircraft to tilt significantly to the left or right.

An object of the present invention is to eliminate the drawbacks peculiar to the rice transplanter having the above configuration.

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

As shown in Figure 1, the rice transplanter has an engine 1,
A seedling planting device 4 that forms a front traveling body with a transmission case 2 and one propulsion wheel 3 located in the center of the left and right, and plants four rows at the rear of this traveling body;
The rear body equipped with a driver's seat 5 and a control handle 6 is connected, and by rotating the control handle 6, the front traveling body is bent and rotated around the vertical axis P with respect to the rear body. It is designed to perform gymnastics.

The rear fuselage has a rod-shaped sled body 7 that swings up and down with the front end as a fulcrum at the left and right center of the fuselage, and a pair of sled bodies 8, 8 that swing up and down integrally on the left and right sides of the fuselage with the front end as the fulcrum. The central sled body 7 extends downward from the seedling planting device 4 , and is swing-driven by a single-acting hydraulic cylinder 9, and the left and right sled bodies 8, 8 are driven by separate single-acting hydraulic cylinders 10. It is configured like this.

At the bottom of the seedling planting device 4 , there is a pair of side floats 11 for leveling the planting area, one on the left and one on the left.
and one central float 12 for leveling the planting area of the two central rows are each mounted so as to be able to swing vertically around a rear fulcrum, and the central float 12 controls the height of the seedling planting device 4. A mechanism is provided for automatically controlling the elevation of the sled bodies 7 and 8 so as to maintain the ground pressure of the sensor float 12 within a set range.

FIG. 3 shows a schematic configuration of the automatic elevation control mechanism, in which the rear part of the sensor float 12 is pivoted to one end of a pel crank 13 that is pivoted to a fixed frame portion of the seedling planting device 4 , The other end of the pel crank 13 and the control valve 14 for the two hydraulic cylinders 9 and 10 are linked together, and during this linkage mechanism, the pel crank 13 is biased and rotated to connect the rear fulcrum of the sensor float 12. A spring 15 is provided to elastically press the ball in the direction of contact with the ground. When the sensor float ground pressure and the tension of the spring 15 are balanced within the set range, the control valve 14 is held neutral, and when the sensor float ground pressure increases, the valve 14 is operated by inserting it into the spring 15. to control the descent of the sled bodies 7, 8, and when the sensor float ground pressure becomes lower than a set range, operate the valve 14 with the force of the spring 15 to control the sled bodies 7, 8 to rise freely; By maintaining the ground pressure of the sensor float within a set range, the height of the seedling planting device 4 relative to the field surface is kept substantially constant.

The basic configuration of the elevation control mechanism has been described above, and the circuits of the two hydraulic cylinders 9 and 10 have been further devised as follows.

That is, both the hydraulic cylinders 9 and 10 are connected in parallel to the secondary port of the control valve 14,
A check valve 16 is interposed in the branched oil path to the hydraulic cylinder 9 of the central sled body 7 to prevent the flow from the hydraulic cylinder 9 to the branch point side, and the internal pressure of the hydraulic cylinder 9 and the internal spring A valve mechanism 19 is provided which is configured to shift the spool 18 based on the balance of the valve 17 and prevent the cylinder internal pressure from increasing beyond a set value.

According to the above configuration, pressure oil can flow into the hydraulic cylinder 9 of the central sled body 7 from the valve 14 only when the internal pressure thereof is lower than the set value and also lower than the internal pressure of the hydraulic cylinders 10 of the left and right sled bodies 8. It's summery. Therefore, when the rear fuselage load is relatively small and the internal pressure of the central sled hydraulic cylinder 9 is below the set value, both hydraulic cylinders 9 and 10 equally support the fuselage rear load, and when the fuselage rear load increases, ,
While the internal pressure of the central sled body hydraulic cylinder 9 rises to the set value and is held there, the internal pressure of the left and right sled body hydraulic cylinders 10 rises above the set value and the load by the left and right sled bodies 8 is equalized. is greater than the load on the central sled body 7.

Note that the load at the rear of the aircraft varies depending on the amount of seedlings loaded into the seedling planting device 4 , the amount of spare seedlings, the backward tilting moment of the aircraft due to the reverse torque from the propulsion wheels 3, and the weight of the driver. This is float group 11,1
2 and sled bodies 7 and 8.

The control valve 14 is also connected to a manual lever 20, and the lever 20 is moved to A when planting.
By switching the valve 14 to the
can be operated only by the sensor float 12, and when the lever 20 is switched to the D position, the sled bodies 7 and 8 can be driven downward by directly operating the valve 14 with manual operating force regardless of the sensor float 12. Further, by holding the lever 20 at the N position, a neutral lock state for lifting and lowering can be obtained. The spool 18 of the valve mechanism 19 is linked to a planting clutch lever 21, and the spool 18 can be freely shifted at the planting clutch engaged position X, and the spool 18 is engaged with the spring 17 at the planting clutch disengaged position Y. The central sled body hydraulic cylinder 9 is cut off from being supplied with pressure oil by being pulled out, and the oil is drained from the cylinder 9.

Therefore, when changing direction in the field or moving backwards after disengaging the planting clutch, or when driving on the road, the load at the rear of the aircraft is reduced by the left and right sled bodies 8, 8 and the float groups 11, 12, or by only the left and right sled bodies 8, 8. is supported, and the aircraft is stabilized in the lateral direction. still,
The central sled body 7 is lightly spring-biased in the upward swinging direction, and is automatically swung upward and retracted when traveling with the planting clutch disengaged as described above. Incidentally, when traveling on a road, it is preferable that the left and right sled bodies 8 are equipped with wheels 22 as shown by imaginary lines in FIG.

As described above in the embodiments, the rice transplanter according to the present invention has a pair of sled bodies 8 on the left and right sides of the central sled body 7, which move up and down integrally.
8 is arranged to be able to be raised and lowered by a hydraulic cylinder 10, and a valve mechanism 19 is provided in the oil path to the lifting hydraulic cylinder 9 of the central sled body 7 to keep the internal pressure of the hydraulic cylinder 9 below a set value, This valve mechanism 19
A reversal valve 16 that connects the lifting hydraulic cylinders 10 of the left and right sled bodies 8 to the upper side and prevents the flow of pressure oil from the hydraulic cylinders 9 of the central sled body 7 to the left and right sled body hydraulic cylinders 10. , the float group 11, 12 and the central and left and right sled bodies 7, 8 can stably support the load at the rear of the aircraft during normal planting runs. When the seedling planting device 4 is pushed up or floats up, the load on the central sled body 7 is automatically kept constant, and the other parts are supported by the left and right sled bodies 8, so that the front Part propulsion wheel 3
The three-point contact between the left and right sled bodies 8 and 8 reliably supports the aircraft, preventing it from tilting sideways or overturning, greatly improving safety.

[Brief explanation of drawings]

The drawings illustrate embodiments of the rice transplanter according to the present invention, with FIG. 1 being an overall side view, FIG. 2 being a plan view, and FIG.
The figure is a perspective view of the control mechanism, and FIG. 4 is a diagram of the hydraulic circuit configuration. 3... Propulsion wheel, 4 ... Seedling planting device, 7... Central sled body, 8... Left and right sled body, 9... Hydraulic cylinder,
10...Hydraulic cylinder, 16...Check valve, 19...
...Valve mechanism.

Claims (1)

[Claims] 1. A small propulsion wheel 3 is installed at the left and right center of the front part of the fuselage, and a seedling planting device 4 with a plurality of floats 11 and 12 arranged in parallel is connected to the rear of the fuselage, and the seedling planting device 4 is located at the lower left and right center. The sled body 7 installed in the seedling planting device 4 is automatically raised and lowered by a hydraulic cylinder 9 that is controlled based on the ground pressure detection result of the ground sensor installed in the seedling planting device 4, and the sensor ground pressure is maintained within a set range. In the rice transplanter configured as shown in FIG. A valve mechanism 19 is provided in the oil path for maintaining the internal pressure of the hydraulic cylinder 9 below a set value, and a hydraulic cylinder 10 for lifting and lowering the left and right sled bodies 8 is connected to the upper side of the valve mechanism 19, and From the hydraulic cylinder 9 of the central sled body 7 to the left and right sled body hydraulic cylinders 1
A rice transplanter characterized by being provided with a check valve 16 that prevents pressure oil from flowing toward zero.