JPH05184206A - Hydraulic driving unit for agricultural working machine - Google Patents

Abstract

PURPOSE:To simplify a circuit construction by installing a double acting auxiliary hydraulic cylinder in parallel with a hydraulic cylinder controlled with a control valve for the horizontal control. CONSTITUTION:A double acting auxiliary hydraulic cylinder 5 is installed in parallel with and separate from a hydraulic cylinder 4 controlled with a control valve 3 for the horizontal control and either of the hydraulic cylinders 4 and 5 is alternatively operated. Thereby, the formation of a special hydraulic circuit for expansion and contraction control of the auxiliary hydraulic cylinder is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drive system for agricultural work machines, and can be used for a tiller connected to a tractor, a combine harvester, and a seedling planter.

[0002]

2. Description of the Related Art In recent years, many tractors have been commercialized that incorporate a horizontal control device for constantly maintaining a horizontal tilling device connected to the rear part of the tractor. This horizontal control is also applied to combine harvesters and seedling planting devices. Is being adopted. In this horizontal control, a horizontal sensor is provided on the traveling vehicle body or working device side on the main body side, and a hydraulic cylinder that corrects the posture of the working device is interposed between the main body side and the working device, and the traveling vehicle is tilted in the left-right direction. Even so, the expansion / contraction of the hydraulic cylinder is controlled so that the working device is always horizontal.

[0003]

In such an agricultural work machine, in addition to horizontal control, another hydraulic cylinder may be provided for changing the front-back posture of the work device or moving the work device laterally in the lateral direction, for example. In this case, not only the hydraulic circuit for connecting the same hydraulic pump to each hydraulic cylinder is configured, but also the operation valve for operating these is provided as a separate configuration, so the configuration becomes complicated and the manufacturing cost is reduced. Also has the drawback of becoming high.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems, and a cylinder for horizontal control is provided by slightly improving a standard equipped agricultural working machine equipped with horizontal control. It is intended to provide a device for controlling the auxiliary cylinders other than the above, and therefore, the following technical measures were taken.

That is, the hydraulic oil sent from the hydraulic pump P is diverted by the shunt valve 7, a constant amount of hydraulic oil is sent to the control valve 3 for horizontal control, and the remaining hydraulic oil is used for lifting the working machine. A hydraulic drive device for an agricultural work machine configured to feed to a control valve 8, wherein a double-acting auxiliary hydraulic cylinder 5 is provided in parallel with a hydraulic cylinder 4 controlled by the control valve 3 for horizontal control. The feature is the construction of a hydraulic drive system for agricultural work machines.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment shown in the drawings has been described by taking a horizontal control device for a tractor as an example. First, when the configuration is described, the hydraulic oil sent from the hydraulic pump P is divided into the shunt valve 7.
To the horizontal control valve 3 and the rest is sent to the hydraulic control valve 8 for raising and lowering the working machine connected to the rear part of the tractor. The hydraulic oil branched from the diversion valve 7 and the return oil from the horizontal control valve 3 join and flow into the hydraulic control valve 8, and an operating lever (not shown) is moved to send the hydraulic oil to the hydraulic cylinder 10. The hydraulic fluid flowing into the hydraulic cylinder 10 pushes the piston 12 to rotate the lift arm 11 upward.

T is a tank port, and when the hydraulic control valve 8 is switched to the lower side, the hydraulic oil in the hydraulic cylinder 10 returns to the tank through the tank port T. A double-acting horizontal hydraulic cylinder 4 is connected to the horizontal control valve 3 via a hydraulic circuit 2 and a switching valve 20 incorporated in the hydraulic circuit 2, so that the horizontal control valve can be operated when the vehicle body leans. 3 is appropriately switched to expand / contract the horizontal hydraulic cylinder 4. Normally, the switching valve 20 is switched to the horizontal hydraulic cylinder 4 side, and when the work device is not horizontally controlled, it is switched to the auxiliary hydraulic cylinder 5 side described later.

Incidentally, a working device such as a rotary tiller is connected to a three-point link mechanism consisting of a top link on the rear side of the tractor (not shown) and a pair of left and right lower links, and the lift arm 11 And the lower link are connected by a pair of left and right rods, and the lift arm 11 is vertically rotated by the operation of the hydraulic control valve 8 to raise and lower the rotary tiller. Further, the hydraulic cylinder 4 and the piston 13 which is expanded and contracted by the hydraulic cylinder 4 are provided on one of the left and right rods connecting the lift arm 11 and the lower link. By expanding and contracting with the piston 13, this rod is expanded and contracted to change the laterally inclined posture of the rotary tiller connected to the tractor. The horizontal control valve 3 is an electromagnetic valve and is provided on the tractor body side. The hydraulic circuit 2 is provided with a hydraulic outlet 7 to which an auxiliary hydraulic cylinder 5 is connected. The auxiliary hydraulic cylinder 5 is a double-acting hydraulic cylinder, and the hydraulic outlet 15 and the hydraulic outlet 7 provided in the hydraulic circuit 6 of the auxiliary hydraulic cylinder 5 are detachably connected.

The auxiliary hydraulic cylinder 5 and the piston 16 fitted to the auxiliary hydraulic cylinder 5 are components other than the horizontal hydraulic cylinder 4 for horizontally controlling the rotary cultivator, and a working device other than the cultivator, such as a cultivator. It is used to forcibly drive working devices such as seeding devices. As shown in FIG. 2, the horizontal control valve 3 is provided with a terminal 17 connected to a power source and a manual operation mechanism 9 capable of switching the electromagnetic valve circuit of the horizontal control valve 3 with a manual switch lever 18.

In the above example, when performing horizontal control of the working device, the switching valve 20 is switched so that the horizontal control valve 3 and the horizontal hydraulic cylinder 4 communicate with each other, and the piston 13 of the hydraulic cylinder 4 is expanded / contracted to work the working device. Control horizontally. On the other hand, stop the horizontal control, for example, to move the working device laterally, or change the front-back posture of the working device,
Furthermore, when controlling the extension / contraction of another hydraulic operating unit attached to the tractor, the switching valve 20 is set to the auxiliary hydraulic cylinder 5
And the horizontal control valve 3 are switched to communicate with each other, and the working oil is sent to the auxiliary hydraulic cylinder 5 side.

[0011]

Since the present invention is configured as described above, it has the following technical effects. That is, the hydraulic oil sent from the hydraulic pump P is diverted by the shunt valve 7, a constant flow rate of hydraulic oil is sent to the control valve 3 for horizontal control, and the remaining hydraulic oil is moved to the hydraulic control valve 8 for raising and lowering the working machine. And a double-acting auxiliary hydraulic cylinder 5 is provided in parallel with the hydraulic cylinder 4 controlled by the control valve 3 for horizontal control, and either one of the hydraulic cylinders 4 and 5 is selected. Since there is no need to form a special hydraulic circuit for controlling the expansion and contraction of the auxiliary hydraulic cylinder 5 because most of the circuits can be used in common, the circuit configuration is simple, and therefore the inexpensive hydraulic A driving device can be realized.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram.

FIG. 2 is a block diagram.

[Explanation of symbols]

 1 horizontal sensor 2 hydraulic circuit 3 horizontal control valve 4 horizontal hydraulic cylinder 5 auxiliary hydraulic cylinder 6 hydraulic circuit 7 hydraulic outlet 8 hydraulic control valve 10 hydraulic cylinder

Claims (1)

[Claims] 1. A hydraulic fluid sent from a hydraulic pump P is diverted by a shunt valve 7, a constant flow rate of hydraulic fluid is sent to a control valve 3 for horizontal control, and the remaining hydraulic oil is used for raising and lowering a working machine. A hydraulic drive device for an agricultural work machine configured to feed to a control valve 8, wherein a double-acting auxiliary hydraulic cylinder 5 is arranged in parallel with a hydraulic cylinder 4 controlled by the control valve 3 for horizontal control.
A hydraulic drive device for an agricultural work machine characterized by being provided with.