JPH0543322B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to a hydraulic control system for a riding-type rice transplanter.

[Conventional technology]

In this type of hydraulic control system, a sensing valve detects the levitation force applied to the float to control the elevation of the planting machine, and the operating sensitivity of the sensing valve is adjusted using a sensitivity adjustment means, and the hydraulic - A common planting lever is known that is used to switch between pressurizing, locking, and discharging the hydraulic pressure of the hydraulic cylinder that raises and lowers the planting machine, and at the same time switches the planting clutch. There is.

In this case, the hydraulic/planting common lever can apply operating force to the sensing valve and set the sensing valve to any of the states of pressurizing, locking, and discharging the hydraulic cylinder. . When the hydraulic pressure/planting common lever is not operated to lift or lock, the sensing valve automatically performs a switching operation according to the floating force applied to the float and the adjustment force added by the sensitivity adjustment means, and This will switch between applying, locking, and releasing pressure to the cylinder to control the elevation of the planting machine.

In addition, when the hydraulic pressure/planting common lever is operated to the lift side, the sensing lever is forcibly switched to apply pressure to the hydraulic cylinder, lift the planting machine, and then proceed to the next step. When operated in a locked manner, the hydraulic cylinder can be locked and its lifted state can be maintained.

[Problem to be solved by the invention]

The problem with this type of hydraulic control is that it is controlled by a shared hydraulic/planting lever, so in the lifted state, the planting clutch is released and the planting machine cannot be operated. . For this reason, it is not possible to adjust the operation timing of the planting machine in the lifted state.

Although the headland can be leveled with the hydraulic cylinder locked, the planting clutch is released and the planting machine cannot be operated. Moreover, in order to obtain a headland leveling effect, it is better to put the hydraulic cylinder in a state of exhaust pressure so that the load of the planting machine is applied to the float.

Therefore, when planting on the headland, the sensitivity adjustment means must be used to lower the sensitivity of the sensing valve, and the hydraulic/planting common lever must be in a state where no forced control is applied to the sensing valve, that is, in a locked state. Must be. Therefore, the sensitivity adjustment means must be operated during this headland planting.

In addition, when driving on the road, the hydraulic/planting common lever must be operated in the order of lift and lock to raise the planting machine, but if operated incorrectly, the planting machine will lower, causing the planting body to There is also a risk of damaging the float etc.

The present invention has been made for the purpose of improving each of the above-mentioned problems.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a state in which the hydraulic cylinder and the sensing valve communicate with each other, and a state in which the flow path between the hydraulic cylinder and the sensing valve is blocked. and,
A three-stage switching valve that can switch between three stages of discharging pressure oil from a hydraulic cylinder is provided, and the three-stage switching valve can be switched by an adjustment lever of a sensitivity adjustment means. It is.

[Effect]

With the above configuration, a three-stage switching valve that switches the oil path between the hydraulic cylinder and the sensing valve can be configured.
By switching the sensitivity adjustment lever to the lock state, the planting machine can operate in a lifted state, and headland planting can be performed with the hydraulic cylinder released (released), and it is also possible to drive on the road. This makes it possible to reliably maintain the lift condition of the planting machine at the time of use.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

In the figure, reference numeral 1 is a running body of a riding rice transplanter, and the front side of this running body 1 is equipped with a front wheel 2 as a steering wheel, and the rear side is equipped with a rear wheel 3. Part of the output from the engine mounted in the front of the vehicle 1 is transmitted to the front wheels 2 and rear wheels 3, allowing the vehicle to travel on its own. Further, the traveling vehicle body 1 is provided with a control section consisting of a driver's seat 4, a handle 5, etc., and a planting work machine 7 is attached to the rear end of the traveling vehicle body 1 via an elevating mechanism 6 consisting of a link mechanism. There is.

The above-mentioned planting work machine 7 has a seedling platform 9 disposed on the machine body 8, supported by slide guides 10 and 11, and a seedling retrieval port of a seedling receiving member 12 disposed corresponding to the lower end of the seedling platform 9. The planting body 13 is capable of cutting and planting pine-shaped seedlings one by one, and the planting work machine 7 is equipped with a center float 14 and side floats 15, 15 on the lower side so as to be able to float above the field surface. ing. The center float 14 has a spool-type sensing valve 16 at its front part.
It is connected to the aircraft body 8 via. That is, the sensing valve 16 has a valve housing 16a pivotally connected to the body 8, and a spool rod 16 thereof.
b is pivotally connected to the center float 14,
Spool 16c in the valve housing 16a
The position is configured to have three points: a pressurizing position A, a locking position B, and a discharging position C.

Further, the sensitivity adjusting means 17 for adjusting the sensitivity of the sensing valve 16 includes links 17a and 17b that are pivotally connected to respective pivot points of the sensing valve 16, and both links 17a and 17b are connected to each other at one end. The inner wire 18a of the control wire 18 is connected to one link 17a via a spring 19. The inner wire 18a of the control wire 18 is connected to a sensitivity adjustment lever 20 provided on one side of the driver's seat 4, and a portion of the sensitivity adjustment lever 20 is connected to the vehicle body 1 via a universal joint. I support you.

A control panel 21 corresponds to the lever 20, and there is a guide slit 22 having a locking groove 22a for selecting a sensitivity setting position and maintaining the sensitivity state, and the lever 20 passes through the guide slit 22. are doing.

A lock groove 22b is formed at one end of the guide slit 22 at a fixed position for locking the hydraulic cylinder, and a lock groove 22c is formed at a headland operation position for exhaust pressure.

A spool-type three-stage switching valve 23 is provided which is closed when the lever 20 is in the lock groove 22b, pressurized when the lever 20 is removed from there, and released pressure when it is in the lock groove 22c. , this switching valve 23 includes a hydraulic cylinder 24 that moves the lifting mechanism 6 up and down, and the sensing valve 16.
It is installed between the hydraulic system lines. The three-stage switching valve 23 is connected to the hydraulic cylinder 24 as described above.
It has become possible to perform three-stage switching: a state in which the hydraulic cylinder 24 and the sensing valve 16 communicate with each other, a state in which the flow path between the hydraulic cylinder 24 and the sensing valve 16 is blocked, and a state in which the pressure oil in the hydraulic cylinder 24 is discharged. There is.

The configuration of the hydraulic system is shown in detail in FIG. Here, the oil in the oil tank 26 is supplied by the pump 25 to the hydraulic cylinder 24 via the sensing valve 16 and the switching valve 23, and pressure oil is supplied to the hydraulic cylinder 24. At this time, the elevating mechanism 6 can be raised. In addition, in the figure, the code 2
7 is a safety valve.

Further, on the other side of the driver's seat 4, a hydraulic/planting common lever 28 is provided, and passes through a guide slit 30 formed in the operation panel 29. The guide slit 30 has a planting position a in which a planting clutch (not shown) is turned on, a lift lowering position b in which the sensing valve 16 is placed in that position to discharge pressure from the hydraulic cylinder 24, and a lift lowering position b in which the hydraulic cylinder 24 is placed in a locked position. A neutral position c is provided in which the sensing valve 16 is placed in a lock position in order to do this, and a lift position d is provided in which the sensing valve 16 is placed in a pressurized position in order to supply pressurized oil to the hydraulic cylinder 24 and pressurize it.

Next, the operation of this hydraulic control system will be explained. When performing rice planting work in a field, the hydraulic/planting common lever 28 is moved from the lift lowering position b to the planting position a. As a result, the sensing valve 16 becomes free, and receives the buoyant force applied to the float 4 to move the spool rod 16b up and down, switching between three positions: pressurizing position, locking position, and exhausting position. The planting depth is automatically adjusted by switching between pressurization, locking, and exhaust pressure to maintain the relative level between the planting machine and the float within a certain range.

In this case, depending on the hardness and softness of the field, a sensitivity adjustment lever 20 is used to adjust the sensitivity of the sensing valve 16.
It is necessary to change the set position. Then, the lever 20 is operated to shift the lever 20 to the selected one of the locking grooves 20a, and the tension of the spring 19 is changed by the tension of the inner wire 18a of the control wire 18, and this is applied to the sensing valve 16. It is.

In addition, to interrupt rice planting work, move the hydraulic/planting common lever 28 from the planting position a to the lift lower position b.
, the planting clutch is released and the planting body 13 is stopped. When performing operations such as turning in the field, the hydraulic/planting common lever 28
is further switched to lift position d. By this,
The sensing valve 16 is forcibly set to the pressurized position so that pressurized oil is supplied to the hydraulic cylinder 24 and the planting machine is placed in a lift condition. Thereafter, when the oil pressure/planting common lever 28 is placed in the neutral position c, the oil passage of the hydraulic cylinder 24 is cut off, and the oil passage becomes locked.

In this case, the sensitivity adjustment lever 20 is
2a, the switching valve 30 is open so as to communicate between the hydraulic cylinder 24 and the sensing valve 16.

If it is necessary to drive the planting machine in the lifted state for the purpose of adjusting the planting timing in the planting machine, the sensitivity adjustment lever 20 is inserted into the lock groove 22b. As a result, the switching valve 23 is switched and the communication between the sensing valve 16 and the hydraulic cylinder 24 is cut off, so no matter how the hydraulic/planting common lever 28 is operated from now on, the hydraulic cylinder 24 will be in the locked state. Since this is maintained, the lever 28 can be returned to the planting position a and the planting machine can be driven in the lifted state.

Further, even if the hydraulic/planting common lever 28 is accidentally removed from the lift position d while driving on the road, the lift will not be lowered because the sensitivity adjustment lever 20 is in the lock groove 22b. In this way, both the oil pressure/planting common lever 28 and the sensitivity adjustment lever 20 double ensure that the lifted state is maintained, so failures in lowering the lift can be sufficiently avoided when driving on the road, making it safer. Sexuality increases.

Further, the headland can be leveled and planted while the full load of the planting machine is applied to the float 14. That is, if the sensitivity adjustment lever 20 is placed in the lock groove 22c to discharge pressure oil from the hydraulic cylinder 24, then the hydraulic/planting common lever 28 is set to the planting position a and the planting operation begins. be able to. In this case, the sensing valve 16 is not functional and the float 14 is used with constant load,
This will effectively level the rough headland and allow headland planting.

〔Effect of the invention〕

As described in detail above, the present invention provides a state in which the oil passage between the hydraulic cylinder and the sensing valve is communicated with the hydraulic cylinder and the sensing valve, and a state in which the flow path between the hydraulic cylinder and the sensing valve is blocked. The three-stage switching valve, which can switch between three stages of discharging the pressure oil of the hydraulic cylinder, is switched with the sensitivity adjustment lever to lock the hydraulic cylinder, and by operating the hydraulic/planting common lever, planting can be done. The planting work machine can be driven with the planting work machine raised, allowing maintenance and inspection of the planting work machine.

Further, since the sensitivity adjustment lever can lock the descending of the planting machine, there is no need to provide a separate locking lever, which simplifies the structure and reduces erroneous operations.

Furthermore, when entering the field and planting after inspecting the lock, if you adjust the sensitivity according to the field, the lock will inevitably be released, so you can plant with the lock locked and plant the rice in the field. It is possible to avoid situations where seedlings are scattered.

Furthermore, when driving on the road, the hydraulic cylinder can be locked twice using both the hydraulic/planting common lever and the sensitivity adjustment lever, so the lifting state of the planting work machine is sufficiently ensured and safety is high.

[Brief explanation of drawings]

Figure 1 is a side view showing one embodiment of the present invention, Figure 2 is a side view showing one embodiment of the present invention;
The figure is a plan view of the same, Figure 3 is a side view showing the control system of the sensing valve, and Figure 4 is a sensitivity adjustment lever and hydraulic pressure.
A plan view showing each operation position of the common planting lever, and FIG. 5 is a circuit configuration diagram of the hydraulic control system. 1... Running vehicle body, 2... Front wheel, 3... Rear wheel, 4
...driver's seat, 5...handle, 6...lifting mechanism,
7... Planting work machine, 8... Body, 9... Seedling mounting stand, 10, 11... Slide guide, 12... Seedling receiving member, 13... Planting body, 14... Center float, 15... ...Side float, 16...Sensing valve, 16a...Valve housing, 16b...Spool rod, 16c...Spool, 17...Sensitivity adjustment means, 17a, 17b...Link, 18...Control wire, 18a...Inner wire ,1
9... Spring, 20... Sensitivity adjustment lever, 2
1...Operation panel, 22...Guide slit, 22
a, 22b...Lock groove, 23...Switching valve,
24...Hydraulic cylinder, 25...Pump, 26...
...Oil tank, 27...Safety valve, 28...Hydraulic pressure/planting common lever, 29...Operation panel, 30...Guide slit.

Claims (1)

[Scope of Claims] 1. A sensing valve detects the levitation force applied to the float to control the elevation of the planting machine, and the operating sensitivity of the sensing valve is adjusted by a sensitivity adjustment means. In a rice transplanter that uses a shared lever to switch between pressurizing, locking, and discharging the hydraulic pressure for the hydraulic cylinder that raises and lowers the planting machine, the planting clutch is also switched at the same time. and the above sensing valve,
a state in which the hydraulic cylinder and the sensing valve are communicated;
A three-stage switching valve is provided that can perform three-stage switching between a state in which the flow path between the hydraulic cylinder and the sensing valve is cut off and a state in which pressure oil from the hydraulic cylinder is discharged. A hydraulic control system for a rice transplanter that is characterized by being able to switch operations using an adjustment lever.