JPS6038755Y2 - Packer device for ground stabilization device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a packer device for a ground stabilization device that injects a ground stabilizing chemical into a predetermined location in the ground.

Conventionally, as a method for strengthening soft ground, etc., it has been common practice to inject ground stabilizing chemicals into the ground using injection pipes such as double-pipe injection pipes. There is a method of sealing the gap between the periphery of the injection pipe and the borehole wall in order to prevent it from spouting or leaking upward or downward along the periphery of the injection pipe.

Mechanical packers, air packers, etc. are available as methods for this purpose, but both have drawbacks such as increased equipment size and are not widely used.

Therefore, a packer device that eliminates these conventional drawbacks was invented and a patent application was filed.

(Japanese Patent Application No. 53-21004) The present invention is achieved by lowering a free piston fitted in a part of a cylinder formed in the upper part of a double pipe by the pressure of the main agent (or auxiliary agent) of a ground hardening chemical. The fluid pressure of the generated hydraulic oil causes the elastic sleeve provided below the double pipe to swell to a predetermined diameter, thereby reliably sealing the gap between the injection pipe and the soil.

Thereafter, the main agent and auxiliary agent are stirred and mixed within the hollow rod and are injected onto a predetermined ground.

This device is less likely to break or malfunction than the packer parts of conventional devices, has a relatively simple structure, and can perform efficient and economical chemical injection.

However, in the above-mentioned device, as shown in FIG. 1, the free piston 50 presses the hydraulic oil with the main agent and gradually descends, passing through the chemical mixing hole 52 formed in the hollow rod 51. At times, the main agent pushing the free piston 50 flows into the chemical injection passage 53 of the hollow rod 51 through the communication hole 52, mixes with the auxiliary agent injected into the injection passage 53 from above, and is injected into the ground. It will be done.

According to the above-mentioned structure, it is possible to stir and mix the medicinal solution without requiring a mix chamber, but the auxiliary agent in the injection passage 53 or the mixed medicinal solution flows back into the passage space 54 from the flow hole 52 and solidifies, causing the piston 50 to be mixed. This had the disadvantage of poor operation.

These drawbacks tend to occur particularly when the injection pressure of the chemical solution changes, such as when stopping the injection of the drug solution.

The purpose of the present invention is to provide a packer device for a ground stabilization device that eliminates the above-mentioned drawbacks, prevents backflow of the chemical solution, keeps the piston in good working condition, and performs accurate and stable chemical injection work. do.

Embodiments of the present invention will be described based on the drawings.

Fig. 1 is a partial sectional view of a conventional packer device, Fig. 2 is a longitudinal sectional front view of the present invention, and Fig. 3 is a partially enlarged sectional view of a valve.
FIG. 4 is a partially cross-sectional explanatory diagram, FIG. 5 is a cross-sectional view taken along the line X--X of FIG. 2, and FIGS. 6 and 7 are operation explanatory diagrams.

To explain the configuration of this embodiment, as shown in FIG.
and a joint portion C, and a hollow rod D passing through these and having a central flow passage 6b serving as a chemical liquid injection passage in the center.

The cylinder part A includes a cylinder 1, and within the cylinder 1, a mixing valve 2, a socket 3, and a piston 4 are sequentially arranged in the vertical direction, and the upper end of the mixing valve 2 has a double pipe as shown in FIG. A chemical liquid injection tube 60 made of a rod is screwed onto the tube.

The mixing valve 2 has an upper part 7 as shown in FIGS. 2 and 3.
, the middle part 8 and the lower part 9 and each of the above parts? , 8.
It consists of a central circulation 6a for the chemical solution that passes through the center of the tube 9.

The upper part 7 is provided with a joint means to be connected to an inner tube for drug injection (not shown) of the double-tube rod, and the lower part 9 forms a spiral part to be screwed into the socket 3.

The central part 8 has a cylindrical shape, and four check valves 10, 10, . . . are arranged around a central flow passage 6a bored in the center.
Form...

This check valve 10 is formed by a ball-shaped valve body 13 and a spring 14 that open and close an inflow path 11 into which a chemical solution flows, and is formed with an outflow path 12 that communicates between a valve chamber 16 and a central flow path 6a. .

On the outer circumferential wall of the central portion 8, there are flow passages 15a, 1 through which the chemical solution flows.
5a... are formed in the axial direction.

In this embodiment, eight of these flow passages 15a, 15a, .・
The position, shape, number, etc. of ... can be determined arbitrarily.

Further, the structure, number, etc. of the check valve 10 described above can be appropriately selected within the scope of the gist of the present invention.

The lower part 9 of this mixing valve 2 is screwed into the socket 3.

This socket 3 has a lower part screwed into the upper end of the hollow rod D, and a liquid medicine flow path 15b is formed between the outer peripheral surface and the inner peripheral surface of the cylinder 1, and the liquid medicine is mixed from the circulation space 5. It is guided through the flow path 15a of the valve 2 to the piston chamber 4a in the upper part of the piston 4.

The piston 4 is fitted in the cylinder 1 so as to be able to move up and down, and as mentioned above, is lowered by the pressure of the chemical liquid flowing through the flow path 15b of the socket 3, and presses the oil in the oil tank 19 from above. be.

As described above, the hollow rod D has its upper end screwed into the lower part of the socket 3, passes through the center of the packer main body 20, and has its lower end screwed into the plug 31 of the joint portion C.

The packer part B is composed of a packer main body 20 and an elastic sleeve 24 made of an elastic material attached to the middle of the packer main body 20 by an upper collar 21 and a lower collar 22.

The packer main body 20 has an upper end screwed into the cylinder 1 and a lower end screwed into the joint sleeve 30, and an oil flow path 25a is formed between the outer wall of the hollow rod D inserted through the center, Below the flow path 25a, the expansion chamber 26 of the elastic sleeve 24 is connected to the flow path 25b.
It is connected with.

In the figure, 23 is an oil supply hole.

The joint part C is composed of a joint sleeve 30 that is screwed into the lower part of the packer main body 20 and a plug 31 for locking the lower part of the hollow rod D. Metal crowns and bits or strainers, etc. that are not connected are connected.

To explain the operation of the present invention configured as above, the sixth
As shown in the figure, it is attached to an injection pipe 60 formed as a double pipe rod, and is inserted into soil 61 that has been previously excavated to a predetermined depth with a boring machine at a spacing 62 of about 2-3 cm. The upper part of the injection pipe 60 is connected to a grout pump using a double slivel, a hose, etc., and the ground stabilizing chemical solution is injected.

That is, after being inserted into the soil 61, when the main agent, liquid A, first flows into the circulation space 5, the liquid A flows through the chemical liquid flow paths 15a, 15a, . . . formed in the mixing valve 2, and the check valves 10, 10, . . . At this time, the spring 14 of the check valve 10 is adjusted to increase the cracking pressure to, for example, 5 kg/a+! pressure to inflate the elastic sleeve 24,
In other words, the pressure to lower bislin 4 is 3 kg/c.
If n, the valve body 13 will not be lowered by the pressure of the A liquid and the A liquid will not flow into the valve chamber 16, so the A liquid will flow through the flow passages 15a and 1.
It flows into 5a...

After that, liquid A flows through the flow path 15 between the socket 3 and the cylinder 1.
b and reaches the piston chamber 4a, applying pressure from the upper end of the piston 4 to lower it.

When the piston 4 descends, the oil in the oil tank 19 is pressurized, so it passes through the oil flow passages 25a and 25b and flows into the expansion chamber 26, causing the elastic sleeve 24 to expand.

(See FIG. 4) The elastic sleeve 24 swells to a predetermined diameter and presses against the soil 61 as shown in FIG. 7, and cannot bulge out any further.

Therefore, the piston 4 cannot descend any further, and the AM pressure applied to the upper part of the piston 4 gradually increases.

・Since the pressure of liquid A applied to the upper part of this piston 4 is also applied to the valve body 13 of the check valve 10 mentioned above, the pressure of liquid A is applied to the check valve 1 as described above.
0 cracking pressure 5kq/c7I! When this happens, the valve body 13 overcomes the elastic force of the spring 14 and the downward check valve 10 opens, and liquid A is ejected from the circulation space 5 through the inlet passage 11, the valve chamber 16, and the outlet passage 12 into the central flow passage 6a. do.

At this time, if the B liquid is allowed to flow through the central flow passage 6a, the A liquid and the B liquid are mixed and stirred and are injected into the predetermined ground through the central flow passages 6a and 6b.

When the injection of liquid A is stopped at the end of the chemical injection work, no pressure is applied to the upper surface of the piston 4, so the piston 4 rises due to the contraction of the elastic sleeve 24 and the rise of the oil in the oil tank 19, as shown in Fig. 2. returns to the initial state.

On the other hand, in the check valve 10, when the injection pressure of liquid A becomes lower than the cracking pressure, the valve body 13 immediately blocks the inflow passage 11. There is no risk that the liquid will flow back into the circulation space 5, and the mixed chemical will not flow into the piston chamber 4a and adversely affect the operation of the piston 4.

As is clear from the above, the present invention has the following effects: it prevents the backflow of the chemical liquid from the central flow passage, keeps the piston in good working condition, and enables accurate and stable chemical injection work. be.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a partial sectional view of a conventional packer device, Fig. 2 is a longitudinal sectional front view of the invention, Fig. 3 is a partially enlarged sectional view of the valve, and Fig. 4 The figure is a partially cross-sectional explanatory view, FIG. 5 is a cross-sectional view taken along the line X--X of FIG. 2, and FIGS. 6 and 7 are operation explanatory views. 1...Cylinder, 2...Valve, 3
...Socket, 4...Piston, 5...
... Distribution space, 6 ... Central circulation passage 10.
... Check valve, 13 ... Valve body, 1
4...Spring, 19...Oil tank, 24...Elastic sleeve, A...
Part of the cylinder, B... Part of the packer, C...
・・Joint part.

Claims (2)

[Scope of utility model registration request] (1) A cylinder whose upper end is configured as a double-tube rod and which is to be connected to a chemical injection pipe, and an oil tank that is fitted into this cylinder so as to be able to slide up and down and lowered by the injection pressure of the chemical liquid introduced into the cylinder. A part of the cylinder is equipped with a piston that pressurizes the oil inside, a check valve to prevent backflow of chemical liquid, a packer body, and an elastic sleeve that is attached to the packer body and expands due to the pressurizing force of the oil generated when the piston descends. A packer for a ground stabilizing device comprising a part of the packer with a joint sleeve and a joint part with a joint sleeve connected in sequence in the longitudinal direction, and a central flow passage for mixing a chemical solution formed in the longitudinal direction of the axis of each part. Device. (2) A packer device for a ground stabilizing device according to claim 1, characterized in that the check valve installed in the cylinder is constructed of a ball-shaped valve body and a spring.