JPS625384Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for extracting hydraulic pressure from a hydraulic pump installed in a tractor or the like to a working machine.

Conventional hydraulic pressure extraction devices were only equipped with an extraction block having a hydraulic passage for changing the direction of oil pressure extraction and a plug for extracting hydraulic pressure to the outside.
It is necessary to provide the hydraulic passage with a switching valve for changing the hydraulic passage, and there is also the inconvenience that a safety valve must be separately provided.

The present invention was devised to eliminate the above-mentioned inconveniences, and its purpose is to provide a valve seat in the middle of a pressure passage connecting a hydraulic pump and a control valve installed on a tractor or other machine body. , a poppet valve facing the valve seat from the downstream side is urged to be seated by a spring, a plug is removably attached to a hydraulic pressure outlet passage branching from the upstream side of the valve seat, and an inner end of the plug is attached to the poppet valve. By making contact with the valve and holding it open against the spring, it is possible to connect the pressure passage to the body of a tractor or other machine by simply attaching a joint to the hydraulic pressure outlet passage instead of a plug. It is an object of the present invention to provide a hydraulic pressure take-off device for a tractor which can be closed and automatically switched to a hydraulic pressure take-off passage, and which can also operate the poppet valve as a safety valve during high loads.

The structure of the present invention will be described with reference to an embodiment shown in the drawings. Reference numeral 1 denotes a hydraulic tank, and the hydraulic tank 1 is connected to a suction port of a hydraulic pump 3 via a suction passage 2. 4 is hydraulic pump 3
The hydraulic cylinder 8 is a pressure passage leading from the discharge port of the hydraulic cylinder 8 to the control valve 7 via the hydraulic pressure take-off device 5 and the relief valve 6, and is installed in the body of the agricultural tractor together with the hydraulic pump 3.
It is possible to supply pressurized oil to the

Reference numeral 9 denotes a take-out block fixed to the body of the tractor to constitute the hydraulic pressure take-out device 5, and a part of the pressure passage 4 is formed in this take-out block 9. A valve seat 10 is provided in the middle of the pressure passage 4 formed in the take-out block 9 in this way, and a poppet valve 11 is opposed to the valve seat 10 from the downstream side, and is biased to seat by a spring 12. . 13 is plug 1
A tension adjusting shim is clamped between 4 and the spring 12, and 15 is an O-ring for sealing the plug 14. 16 is a hydraulic pressure outlet passage into which the poppet valve 11 is slidably inserted;
It is communicated with the pressure passage 4 further upstream. Further, by screwing a plug 18 into the thus formed hydraulic pressure take-off passage 16 through an O-ring 17, the oil pressure take-off passage 16 is always closed and the inner end of the plug 18 is brought into contact with the poppet valve 11. This is held in contact with the spring 12 to keep the valve open.

Next, the operation of the present invention constructed as described above will be explained. When operating the hydraulic cylinder 8 installed in the tractor body, a plug 18 is attached to the hydraulic pressure outlet passage 16 as shown in FIG. Then, this hydraulic pressure outlet passage 16 is sealed, and the poppet valve 11 is held open against the force of the spring 12. Therefore, the pressure oil discharged from the hydraulic pump 3 is transferred to the pressure passage 4,
It is sent to a hydraulic cylinder 8 via a hydraulic pressure extraction device 5, a relief valve 6, and a control valve 7. It goes without saying that the expansion and contraction of the hydraulic cylinder 8 is controlled by switching the control valve 7.

On the other hand, when hydraulic pressure is to be supplied to a working machine (for example, a front loader, etc.) not shown, the plug 18 is removed and the joint 19 is attached to the hydraulic pressure outlet passage 16 as shown in FIG. When the plug 18 is removed in this way, the pressing force against the poppet valve 11 is released, so the poppet valve 11
is seated on the valve seat 10 by the tension of the spring 12.
Therefore, hydraulic pressure is not supplied to the control valve 7 on the machine body side, and the hydraulic pressure is extracted from the upstream side of the valve seat 10 through the hydraulic pressure extraction passage 16 and the joint 19 to the working machine side (not shown). It is needless to mention in detail that a control valve for a working machine is interposed between the joint 19 and a hydraulic cylinder of a working machine (not shown), as in the conventional art.

Furthermore, when the hydraulic pressure supplied to the working machine side becomes larger than the seating force of the poppet valve 11, the poppet valve 11 is pushed open against the spring 12, so that the poppet valve that switches the flow path as described above is activated. 11 can also be operated as a safety valve. Therefore, there is no need to separately provide a switching valve and a safety valve as in the conventional case. It goes without saying that the present invention is applicable not only to tractors but also to various types of mobile agricultural machinery equipped with hydraulic devices.

In short, the present invention provides a valve seat in the middle of a pressure passage that connects a hydraulic pump and a control valve installed in a machine body such as a tractor, and a poppet valve facing the valve seat from the downstream side is biased to seat with a spring. In addition, a plug is removably attached to a hydraulic pressure outlet passage branching from upstream of the valve seat, and the inner end of the plug is brought into contact with the poppet valve to hold the valve open against a spring. Therefore, it is not possible to automatically switch between the hydraulic passage to the body of a tractor or the like and the hydraulic pressure outlet passage to the working machine by simply attaching and removing the plug, but it is necessary to use a poppet valve that switches the passages. It can also act as a pressure limiting valve for the hydraulic pressure outlet passage to the work equipment side.
Therefore, there is no need to separately incorporate a safety valve, and other extremely useful practical effects are achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the hydraulic pressure extraction device for an agricultural tractor according to the present invention, in which FIG. 1 is a hydraulic circuit diagram, FIG. 2 is a sectional view of the main parts showing a state in which hydraulic pressure is not extracted, and FIG. 3 is a cross-sectional view of the main parts showing a state in which hydraulic pressure is extracted. In the figure, 3...Hydraulic pump, 4...Pressure passage, 5...Hydraulic pressure take-off device, 7...Control valve, 8...Hydraulic cylinder, 9...Take-out block, 10...Valve seat, 11...Poppet valve ,
12...Spring, 16...Hydraulic pressure outlet passage, 1
8...Plug, 19...Joint.

Claims (1)

[Scope of utility model registration request] A valve seat is provided in the middle of a pressure passage that connects a hydraulic pump and a control valve installed in a machine body such as a tractor, and a poppet valve facing the valve seat from the downstream side is seated and biased by a spring, and a poppet valve facing the valve seat from the downstream side is seated and biased. Hydraulic pressure for a tractor, etc., characterized in that a plug is removably attached to a hydraulic pressure outlet passage branching from the valve, and the inner end of the plug is brought into contact with the poppet valve to hold the valve open against a spring. Retrieval device.