JPS6128144Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oil spill prevention device in a hydraulic unit.

In a hydraulic unit in which the cylinder is installed at a lower position than the hydraulic oil tank, when the cylinder or hose is disassembled for repair, there has been a problem in which the hydraulic oil in the hydraulic unit flows out from the return pipe due to the siphon phenomenon.

In order to solve the above problems, an apparatus shown in FIG. 1 has been used. That is, a pit 3 is provided on a floor surface 2 on which a hydraulic oil tank 1 is installed, and a cylinder 4 is installed within this pit 3. A switching valve 5 is provided between the hydraulic oil tank 1 and the cylinder 4, hydraulic oil is supplied to the switching valve 5 via a pump 6, a stop valve 8 is provided at the top of the return pipe 7, and a flange is provided on the return pipe 7. A connecting pipe 10 inserted into the hydraulic oil tank 1 was connected through the connecting pipe 9.

In the above equipment, when servicing the cylinder 4, the stop valve 8 was opened to blow in air and the oil joint in the return pipe 7 was cut to prevent oil from flowing out due to the siphon phenomenon. .

The problem with the above method is that the stop valve is often forgotten to open, and a large amount of oil in the hydraulic oil tank often leaks into the pit during repair work.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide an oil spill prevention device for a hydraulic unit that can automatically prevent the siphon phenomenon.

The structure of the present invention will be explained in detail based on the embodiment shown in FIG. An elbow 13 is screwed onto the other end of the valve box 12.

The valve box 12 has a valve seat 14 protruding from the inner periphery of the upper part, a passage 15 in the center, and an upper chamber 16 in the upper part.
will be established. A disk-shaped stopper 17 is fitted into the upper chamber 16 and has a gap (approximately 0.5 mm) between its outer periphery and the upper chamber 16. This stopper 17 has a plurality of small holes 18, 18 (see FIG. 3) on its outer peripheral surface, and an operating rod 19 protruding into the passage 15 from the center of its lower surface. Further, a recessed portion 20 is provided on the inner peripheral surface of the lower surface of the valve seat 14. A cap-shaped valve body 22, which is a truncated cone-shaped seat portion 21 that fits into the passage 15, is fitted into the recessed portion 20 so as to be movable up and down. This valve body 22 has a plurality of small holes 2 in the lower part of the seat part 21.
3, . . . are provided, and the lowered position is determined by a snap spring 24 attached to the inner peripheral surface of the valve box 12. In addition, a circular oil stop valve 26 having a plurality of small holes 25, .
A valve rod 27 that engages with the lower surface of the seat portion 21 is protruded from the upper surface of the valve 6 .

The rest is the same as the conventional one, so the drawings and symbols are omitted.

The embodiment of the present invention is constructed as described above, and when the pump 6 and cylinder 4 shown in FIG. 1 are operated, exhaust pressure is generated in the return pipe 7. The jetting of oil due to this exhaust pressure is blocked by the oil stop valve 26, and the oil stop valve 26 rises due to the exhaust pressure, and the valve rod 27 pushes up the valve body 22, bringing the seat part 21 into close contact with the valve seat 14, and causing the oil to blow out. cut off. Incidentally, the oil blown out from the small holes 25, . . . , 23, .

The hydraulic oil circulates in the above state and the work continues, but even during pump operation, the exhaust pressure in the return pipe 7 drops to zero every time the cylinder 4 completes its stroke, and each time the stopper 17 lowers due to the weight and external pressure. do. This lowering causes the actuating rod 19 to push down the valve body 22 and create a gap in the valve seat 14. As a result, air passes through the small holes 18, 23, 25 and breaks the oil in the return pipe 7. This is in a state where the siphon phenomenon is always prevented, so even if there is a problem such as a leak in the return pipe, the oil in the tank can always be prevented from flowing out due to the siphon phenomenon.

As described above, the siphon phenomenon is prevented every time the exhaust pressure in the return pipe 7 becomes zero.

The present invention is not limited to the configuration of the embodiment, but includes a hydraulic system having equipment located at a position lower than the oil level of the tank, and a tank located at a higher position such as an elevated tank, and piping, etc. located at a lower position. It can be used in any equipment where there is a possibility that the liquid in the tank may leak out due to the siphon phenomenon in the event of trouble.

Since the present invention has the above-mentioned structure and operation, it is possible to avoid problems such as inadequacies in dealing with oil leaks during operation by operators who are inexperienced with hydraulic equipment, inadequacies in handling as a witness to repair work, repair workers' equipment, principles, and siphon phenomenon. Even if a person who lacks the knowledge to prevent oil from leaking out of the tank attempts to disassemble and repair equipment such as hydraulic hoses, piping, cylinders, etc. located lower than the tank, they may forget to take measures to prevent oil leakage, as in the past. This prevents all the oil in the tank from leaking into the pit during repairs.

Furthermore, there is no need to open the valve for sucking air into the return pipe every time a hydraulic system is repaired at a low location such as a pit, and there is no leakage caused by forgetting to open the valve.

[Brief explanation of drawings]

Fig. 1 is a piping diagram showing a conventional device, Fig. 2 is a sectional view of essential parts showing an embodiment of an oil spill prevention device in a hydraulic unit according to the present invention, and Fig. 3 is a plan view of a stopper. . In the figure, 1 is the hydraulic oil tank, 7 is the return pipe, and 12 is the hydraulic oil tank.
is a valve box, 14 is a valve seat, 17 is a stopper, 18 is a small hole, 19 is an operating rod, 21 is a seat portion, 22 is a valve body, 23 is a small hole, 25 is a small hole, 26
is an oil stop valve, and 27 is a valve stem.

Claims (1)

[Scope of utility model registration request] In a hydraulic unit that circulates oil by installing equipment at a lower position than the hydraulic oil tank 1, a valve box 12 whose upper end is open to the atmosphere is fixed vertically at the highest point of the return pipe 7, and the valve box 1
A stopper 17 having a plurality of small holes 18 on the outer periphery and an actuating rod 19 on the lower surface is fitted into the upper part of the valve seat 14 protruding inside the valve seat 2 so as to be movable up and down.
A cap-shaped valve body 22 having a truncated conical seat portion 21 having a plurality of small holes 23, . The valve rod 2 that comes into contact with the lower surface of the seat portion 21
An oil spill prevention device in a hydraulic unit, which is fitted with an oil stop valve 26 having a protruding portion 7.