JPH022162Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is for use when a working machine that uses hydraulic pressure is installed in addition to the hydraulic lift device of an agricultural tractor.
This is an invention related to a hydraulic external extraction device.

(b) Prior art Agricultural tractors are equipped with a hydraulic lift device with a protruding lift arm for the work equipment attachment device installed at the rear of the tractor, but in recent years, hydraulic lift devices other than attachment to the work equipment attachment device have been used for hydraulic lift operations. The number of machines has increased.

Conventionally, an external outlet has not been provided to take out the hydraulic pressure that is controlled through the hydraulic control valve for the tractor's lift arm before it enters the cylinder and use it with a hydraulic work machine located very nearby. It was.

Recently, there has been an increase in the number of hydraulic work machines that have their own hydraulic control valve installed in the work machine body, and only receive pressure oil from the tractor. For example, front loaders, mini-buckshoes, mini-dozers, etc.

These hydraulically powered work machines are not equipped with a hydraulic pump because they do not have a power source, but they are equipped with a hydraulic directional control valve, so only pressure oil needs to be supplied from the tractor. .

Conventionally, the devices shown in Figures 6, 7, and 8 were used to supply pressure oil to these special hydraulic working machines.
A mid-way adapter installed in the middle of the high-pressure pipe 33 as shown in FIG. 9 was used.

(c) Problems to be solved by the invention If an adapter is provided in the middle of the high-pressure pipe as in the prior art described above, the weld between the high-pressure pipe 33 and the adapter 27 may peel off due to the vibration of the tractor. However, when the external extraction hose was connected, the hose was suspended from the adapter, making it unstable.

The present invention aims to solve the problems of the prior art.

(d) Means for solving the problem The purpose of the present invention is as described above. Next, the configuration for achieving the purpose will be explained.

In the hydraulic system of an agricultural tractor, in addition to the external outlet 24 for taking out the pressure oil after being controlled by the hydraulic control valve 12 dedicated to the hydraulic lift arm 10, there is also a block for taking out the pressure oil to the outside before entering the hydraulic control valve 12. A relief valve 22 for the cylinder 25 of the other working machine operated by the pressure oil taken out from the external extraction block is arranged between the pump 23 and the hydraulic control valve 26 of the other working machine, The cylinder head 9 fixed to the front part of the hydraulic case 8 also serves as the external extraction block, and the relief valve 22 is also arranged in the cylinder head 9.

(E) Embodiment The purpose and structure of the present invention are as described above. Next, the structure of the embodiment shown in the attached drawings will be explained.

FIG. 1 is an overall side view of the agricultural tractor.

An engine 2 is arranged inside the bonnet 1,
A front frame 3 protrudes forward from the lower side of the engine 2.

Front wheels 4, 4 are supported so as to be rotatable left and right via a front frame 3 center pin and the like. engine 2
A clutch housing 5 is fixed to the rear end surface, and a transmission case 6 is fixed to the rear of the clutch housing 5. The rear wheels 7, 7 are supported by rear axles that protrude from the transmission case 6 to both sides. A hydraulic case 8 is seated on the upper surface of the rear end of the transmission case 6, and a hydraulic lift arm 10 is rotatably protruded.

A cylinder head 9 of the present invention is attached to the front surface of the hydraulic case 8. A seat 11 is provided further above the hydraulic case 8.

Figure 2 shows the hydraulic case 8 and cylinder head 9.
3 is a front view of FIG. 2 looking at the cylinder head 9, and FIG. 4 is a sectional view of the relief valve 22 of the cylinder head.

The structure will be explained along the flow of pressure oil.

Referring to FIG. 7 which shows a conventional device, the lubricating oil in the transmission case 6 is also used as the hydraulic oil. It is sucked into the hydraulic pump 23 through the low pressure pipe 32. Hydraulic pump 23 is driven by engine 2.

The sucked hydraulic oil is made high-pressure and passes through the high-pressure pipe 3.
3, in this invention, as shown in Figure 2,
The oil enters the cylinder head 9 through the pressure oil port 16 of the cylinder head 9.

The cylinder head 9 also serves as a block for extracting pressure oil from the outside before entering the hydraulic control valve 12.
If it is desired to take out pressure oil in the direction of the cylinder 25 and hydraulic control valve 26 of another working machine shown in the figure, a high pressure hose is connected to the external outlet 15.

After the cylinder is operated, the low pressure oil returns to the cylinder head through the external return port 20.

When the external extraction device is not used, when the blind plug is plugged, the pressure oil leaves the cylinder head and flows into the hydraulic control valve 12 on the hydraulic case 8 through the connecting pipe 21.

Thereafter, pressure oil controlled by the hydraulic control valve 12 pushes the piston 17 and rotates the lift arm 10 via the piston rod 18 and lift crank 19.

FIG. 5 is a hydraulic circuit diagram of the present invention, and FIG. 6 is a hydraulic circuit diagram of a conventional device.

Conventionally, the adapter 27, which is an external extraction block, was only interposed between the hydraulic pump 23 and the hydraulic control valve 12, so an abnormally high pressure could occur due to an accident with the cylinder 25 of another working machine. However, there was no place to absorb it, and the pump 23 and hydraulic control valve 12 were sometimes damaged.

In the present invention, in order to eliminate this problem, a relief valve 22 is provided between the pump 23 and the hydraulic control valve 26 of another working machine.

The relief valve 22 is obliquely mounted on the upper part of the cylinder head 9 in FIG.

Also, as in the past, the cylinder of the hydraulic case 8,
and safety valve 14 for piston 17
is also provided in the cylinder head 9 shown in FIG.

Further, although not shown in FIG. 3, an external outlet 24 is provided on the side surface of the cylinder head 9 and is controlled by a hydraulic control valve 12.

Fig. 7 is a side view of 5 parts of the clutch housing showing a conventional hydraulic external extraction device, Fig. 8 is a drawing showing the state in which external extraction hoses 29 and 30 are installed on the adapter 27, and Fig. 9 is a drawing when the adapter is closed. This is a drawing showing a state in which a blind lid 31 is attached for the purpose of the present invention.

Conventionally, the adapter 27 was suspended in the middle of the high-pressure pipe 33, and the hose 29 for external extraction was added to the adapter 27.
30 was suspended, making it unstable.

(f) Effects of the invention Since the present invention is constructed as described above, it has the following effects.

First, this problem occurs because a hose for external extraction is further suspended from an adapter that is suspended in the middle of a high-pressure pipe as in the past. The weld between the high-pressure pipe and the adapter no longer peels off due to tractor vibration, eliminating the instability that occurs due to tractor vibration.

Furthermore, since the external extraction hose is screwed directly onto the fixed cylinder head, the hose installation work can be done easily.

Second, in the case of conventional hydraulic extraction devices,
Since an external extraction block was placed in the middle of the high-pressure pipe from the pump to the cylinder head, it was not possible to install a relief valve for the cylinder operated by the pressure oil taken out from the external extraction block. Since the idea is to use the external extraction block as the cylinder head, the relief valve 22 can be placed between the pump 23 and the hydraulic control valve 26, and the cylinder 25 caused by an unexpected situation can be
This allowed the high pressure to escape.

Thirdly, both the pressure oil controlled by a dedicated hydraulic control valve and the pressure oil before being controlled can be taken out, making it possible to take out pressure oil in response to the diversification of work equipment. be.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of the agricultural tractor, Fig. 2 is a side sectional view of the hydraulic case, Fig. 3 is a front view of the cylinder head, Fig. 4 is a sectional view of the relief valve, and Fig. 5 is a sectional view of the hydraulic case. Hydraulic circuit diagram, Fig. 6 is a hydraulic circuit diagram of a conventional device, Fig. 7 is a side view showing a conventional external extraction device, Fig. 8 is a diagram showing an external extraction hose attached to an adapter, Fig. 9 This is a drawing in which the adapter is closed with a blind lid. 8... Hydraulic case, 9... Cylinder head,
12... Hydraulic control valve, 14... Safety valve, 15... External outlet, 16... Pressure oil port, 20
...External return port, 22...Relief valve, 24
...External outlet controlled by the hydraulic control valve 12.

Claims (1)

[Scope of utility model registration request] In the hydraulic system of an agricultural tractor, in addition to the external outlet 24 for taking out the pressure oil after being controlled by the hydraulic control valve 12 dedicated to the hydraulic lift arm 10, there is also a block for taking out the pressure oil to the outside before entering the hydraulic control valve 12. A relief valve 22 for the cylinder 25 of the other working machine operated by the pressure oil taken out from the external extraction block is arranged between the pump 23 and the hydraulic control valve 26 of the other working machine, A hydraulic external extraction device for an agricultural tractor, characterized in that the external extraction block is also used as a cylinder head 9 fixed to the front part of the hydraulic case 8, and a relief valve 22 is also arranged in the cylinder head 9.