JPS6145766Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic system for lifting and lowering a working machine of a tractor.

Conventionally, when installing work machines in the front and rear, the hydraulic circuits were completely separate even if the front and rear work machines had one cylinder or two cylinders.

In the former case, the front and rear working machines move up and down at the same time, resulting in unnecessary ridges at the start of the field, incomplete ridges at the end, or unnecessary fertilization, resulting in the effective use of cultivated land. I couldn't do it.

The latter eliminates waste like the former, but in the conventional two-cylinder system, the front and rear cylinders do not interlock, so
At the starting point of the field, it is necessary to set the control lever of the front abdominal work machine to the down position, and after a short period of time, move the control lever of the rear work machine to the down position. Furthermore, at the end point, it is necessary to move the operating lever of the abdominal working machine to the up position and then, after a short pause, move the operating lever of the rear working machine to the up position. Furthermore, since the machine begins to turn at the same time as it is raised, the worker has to operate several levers in a short period of time, which results in the worker neglecting to operate one of them, and as with the former, the farmland cannot be used effectively.

Further, for the above reasons, the work required skill and the work caused great fatigue.

The present invention was developed in view of the above circumstances, and its purpose is to make the work easier without requiring skill as in the past, and to reduce fatigue caused by work. The object of the present invention is to provide a hydraulic system for elevating and lowering a working machine of a tractor.

Hereinafter, the present invention will be explained with reference to the drawings.

In the drawings, reference numeral 9 denotes a tractor, and the front part of the vehicle body 10 of the tractor 9 is equipped with an abdominal working machine 1, and the rear part of the vehicle body 10 is equipped with a rear working machine 2.

The vehicle body 10 is provided with an abdominal cylinder 3 for controlling the elevation of the abdominal working machine 1 and a rear cylinder 4 for controlling the elevation of the rear working machine 2.

In the hydraulic circuit shown in FIG. 2, 5 is an abdominal control valve, and 6 is a rear control valve. The discharge side of the pump 11 is connected to the first input port 5 of the abdominal control valve 5 via the first conduit 12.
The discharge side of the pump 11 is connected to a tank 14 via a second pipe line 13, and a relief valve 15 is provided in the second pipe line 13. Further, the discharge side of the pump 11 communicates with the second input port 5b of the abdominal control valve 5 via a third conduit 16, and a check valve 17 is provided in the third conduit 16. Connection ports 5c and 5d of the abdominal control valve 5 are connected to the fourth and fifth conduits 1
8, 19 into the abdominal cylinder 3.
The output port 5e of the abdominal control valve 5 communicates with the tank 14 via the sixth conduit 20, and the sixth conduit 20 is provided with an unload valve 21. Output port 5 of abdominal control valve 5
e is the seventh hydraulic circuit R of the rear cylinder 4;
It is connected to the input ports 6a, 6b of the rear control valve 6 via the eighth pipes 22, 27,
This eighth conduit 27 is provided with a check valve 23 and a variable throttle 24. The input port 6b of the rear control valve 6 communicates with the head side of the rear cylinder 4 via a second conduit 25.

The pilot port 6c of the rear control valve 6 is connected to the pilot port 21a of the unload valve 21 via a pilot conduit 26.

Drain ports 5f, 6d of the abdominal and rear control valves 5, 6 communicate with the tank 14 via drain lines 28, 29.

The operating lever 7 of the abdominal control valve 5 is equipped with a spring 30.

Now, set up the cultivated land as shown in Figure 3. In order to use the cultivated land sufficiently effectively, it is necessary to start plowing, fertilizing, and ridge work at the starting point S, and to finish the plowing, fertilizing, and ridge work at the end point E.

Next, we will explain the valve operation according to the work situation.

When the tractor 9 is running and the abdominal working device 1 reaches the starting point S, the operating levers 7 and 8 are simultaneously moved to the lowered position.

The operating lever 7 is always subjected to a force acting to return it to the neutral position N due to a spring force. Since no spring force is applied to the operating lever 8, the operating lever 8 attempts to maintain its position.

Therefore, while the operating lever 7 is held in the lowered position, oil flows into the abdominal cylinder 3 and the abdominal working machine 1 is lowered. However, at this time, the spool 11 of the abdominal control valve 5 is connected to the oil circuit to the rear control valve 6, that is, the seventh and eighth valves.
Since the pipes 22 and 27 are blocked, oil does not flow into the rear cylinder 4, and the rear working machine 2 is kept in the same state without moving up or down.

Next, when the rear working machine 2 reaches the starting point S and releases the operating lever 7, the operating lever 7 quickly returns to the neutral position N.

Then, oil flows into the rear cylinder 4, and the rear working machine 2 rises.

When the abdominal working machine 1 reaches the end point E, the operating levers 7 and 8 are simultaneously moved to the raised position. While the operating lever 7 is held in the raised position, oil flows into the abdominal cylinder 3 and the abdominal working machine 1 rises. At this time, the spool 11 cuts off the oil circuit to the rear control valve 6, that is, the seventh and eighth pipe lines 22 and 27, so the rear cylinder 4
No oil flows into the rear working machine 2, and the rear working machine 2 is kept in its original position.

Next, when the rear work machine 2 reaches the end point E,
When you release the operating lever 7, the operating lever 7
returns to the neutral position N, and the circuit leading to the rear control valve 6, that is, the seventh and eighth pipes 2
2 and 27, and the operating lever 8 is held in the raised position, the oil flows into the rear cylinder 4.
, and the rear working machine 2 rises.

The present invention has been described in detail above, and includes the abdominal cylinder 3 for lifting and lowering the abdominal working machine 1 for plowing and fertilizing, and the lifting and lowering operation for the rear working machine 2 for ridge formation after plowing. a rear cylinder 4 carrying out;
It is provided in the hydraulic circuit of the abdominal cylinder 3, and when switching, it switches the vertical movement of the abdominal cylinder 3, and also shuts off the hydraulic circuit R of the rear cylinder 4 when switching the vertical movement, and opens this hydraulic circuit R when in neutral, and then switches the vertical movement. An abdominal control valve 5 that urges the spool to a neutral position by spring force during switching, and a rear cylinder 4.
Since the rear control valve 6 is provided in the hydraulic circuit of the rear cylinder 4 to change the vertical movement of the rear cylinder 4 and to hold the spool in the switching position during switching, the respective operation levers of the abdominal control valve 5 and the rear control valve 6 can be operated. When operated simultaneously, oil is supplied preferentially to the abdominal cylinder 3, and the abdominal working machine 1 is raised and lowered, and when the external force on the operating lever of the abdominal control valve 5 is removed, the spool of the abdominal control valve 5 is placed in the neutral position. As a result, oil is supplied to the rear cylinder 4, and the rear work equipment 2 can be raised and lowered by operating the rear control 6, so the work efficiency is improved without requiring skill as in the past. This makes it easier and reduces fatigue caused by work.

[Brief explanation of the drawing]

Figure 1 is a side view of a tractor equipped with a working machine.
FIG. 2 is an explanatory diagram of the configuration of an embodiment of the present invention, and FIG. 3 is an explanatory diagram of cultivated land cultivated by a tractor. 3 is an abdominal cylinder, 4 is a rear cylinder, 5 is an abdominal control valve, and 6 is a rear control valve.

Claims (1)

[Scope of utility model registration request] An abdominal cylinder 3 for lifting and lowering an abdominal working machine 1 that performs plowing and fertilization, a rear cylinder 4 for lifting and lowering a rear working machine that works on ridges after plowing, and a hydraulic circuit for the abdominal cylinder 3. At the same time, the hydraulic circuit R of the rear cylinder 4 is cut off when the vertical movement is changed, and this hydraulic circuit R is opened when the cylinder is in the neutral position, and furthermore, when the vertical movement is changed, the hydraulic circuit R is opened to the neutral position by the spring force. An abdominal control valve 5 that energizes the spool and a rear cylinder 4 provided in the hydraulic circuit of the rear cylinder 4
1. A hydraulic system for lifting and lowering a work machine for a tractor, comprising a rear control valve 6 for switching the lifting and lowering movement of the spool and for holding the spool in the switching position during switching.