JPH0325565B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grout injection device used for soil improvement.

In recent years, grouting devices have increasingly come in a plurality of structures due to the demand for reliable construction. As something similar to the present invention which will be described in detail later, JP-A-54-
There is one described in Publication No. 152310. To explain this using the reference numerals described in the same publication, when drilling a hole, liquid is sent into the valve body 38 and the liquid is jetted out to the tip, and during injection, the liquid is sent to the outer flow path 17 to move the valve body 38. , inner channel 29, 4
This is the same as the present invention in that the channels 1 and 43 are closed and the internal channel liquid is guided to another location.

However, in this case, when the liquid is sent to the outer channel 17, the liquid in the inner channel does not pass through the inside of the valve body 38, but comes out from the communication hole 57 formed in the spool 14 connected to the valve body 38. The liquid is mixed with the liquid flowing down the outer flow path 17, and the mixed liquid flows into the path 6.
It is different from that of the present invention in that it is injected from the nozzle 62 through the nozzle 62. In this conventional example, in order to make it suitable for injection of instant setting grout,
Even if it is attempted to mix the two liquids as close to the injection port as possible and to perform countercurrent mixing to improve their miscibility, it is impossible due to the concept of the structure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a grout injection device that does not solidify in a pipe even when instant setting grout is injected, and can ensure flow path switching operation.

The present invention will be explained below using specific examples shown in the drawings. The illustrated portion is the distal end portion, which is connected to the double tube on the base side.

Reference numeral 10 denotes a main outer pipe, to which a joint pipe 12 is connected, and to which a tip pipe 16 having a drilling bit 14 at its tip is screwed and connected, and the tip thereof is connected to the spout 1.
It has become 8. The main outer tube 10 is threadedly connected to the outer tube of the double tube on the base side.

A sub-outer tube 22 having an annular recess 20 at its outer periphery is provided inside the main outer tube 10 and the joint tube 12. Conversely, the main outer pipe 10 and the joint pipe 12
are connected to each other via a sub-outer tube 22, and the end surfaces thereof form an inlet 24 continuous in the circumferential direction. Furthermore, due to the formation of the annular recess 20, an annular mixing chamber 26 is formed that is continuous in the circumferential direction between the annular recess 20 and the main outer pipe 10 and the joint pipe 12. Opening at both ends of the annular mixing chamber 26 , an outer channel liquid outlet 28 and an inner channel outlet 30 are formed through the wall of the sub-outer tube 22 .

Reference numeral 32 designates a projecting joint whose projecting portion 34 is fitted into the inner pipe of the double pipe on the base side. The projecting joint 32 has, for example, three protrusions 3 on the outer periphery.
6, and is accommodated in the main outer pipe 10 via this protrusion 36, and between the protrusions 36 and the protrusion joint piece 3.
2 and the main outer pipe 10, the outer channel liquid passes through the inner and outer gaps of the double pipe.

Inside the joint 32, a breech valve 38 is biased by a spring 42 whose seat is a spring seat 40 so as to close the internal flow path.

44 is a spool pipe, the proximal end of which is connected to the protrusion joint 32
It is inserted into the inner flow path and forms part of the inner flow path. A plurality of discharge ports 46 are formed at the tip of the spool pipe 44, and drilling water W is guided into the spool pipe 44.
The air flows from the discharge port 46 to the spout 18 through the narrowed portion 48 of the auxiliary outer tube 22 .
A plurality of communication holes 50 penetrating the wall of the spool pipe 44 are formed between the discharge ports 28 and 30 on the base side of the discharge port 46, and these communication holes 50 are normally closed by the wall of the sub-outer pipe 22. It is blocked.

The spool pipe 44 has a projecting portion 52,
This projecting portion 52 is fitted into the main outer tube 10 in a liquid-tight manner. A spring 56 is interposed between the side portion 54 of the projecting portion 52 and the base end of the auxiliary outer tube 22, and the spool tube 44 is urged toward the base side by the spring 56. Furthermore, when a hydraulic pressure from the outer flow path that is greater than the biasing force of the spring 56 acts on the shoulder 58 of the overhang 52, the spool pipe 44 is pushed down as shown in FIG. 10 to a position where a gap is maintained between the outer flow path outlet 2 and the outer flow path outlet 2.
Open 8. This leads the outer channel liquid into the mixing chamber 26. At the same time, the tip of the spool pipe 44 fits into the narrowed part 48 and blocks the internal channel liquid that is about to exit from the discharge port 46, and also closes the communication hole 50.
communicates with the inner channel liquid discharge port 30 and guides the inner channel liquid to the mixing chamber.

In such an injection device, drilling is performed while applying rotational force and pressurizing force to the injection pipe while supplying drilling water W to the inner flow path and ejecting it from the spout 18.

At the time of injection, grout liquid is sent to both the inner and outer channels, and the outer channel grout A is guided from the discharge port 28 and the inner channel grout B is guided from the discharge port 30 to the mixing chamber 28. As a result, the grouts A and B meet in the mixing chamber 26 in a countercurrent manner, are contacted and mixed, and are injected into the surrounding ground from the injection port 24 in all directions as a mixed liquid.

As mentioned above, in the device of the present invention, the mixing chamber is provided near the injection port, and each liquid is introduced thereinto independently.
Even if instant setting grout is injected, there will be no solidification and blockage within the pipe. In addition, the inner channel grout was guided to the injection port by breaking the wall of the spool pipe, so
Mixing can be performed near the injection port, and the structure of the injection pipe can be simplified.

Note that counter-current mixing as in the above example improves the mixability, and if the mixture is mixed in the annular mixing chamber and then injected from the omnidirectional opening injection port, the injection speed becomes lower and finer injection becomes possible. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of the apparatus of the present invention when drilling a hole, and FIG. 2 is a longitudinal cross-sectional view of the apparatus during injection. 10...Main outer pipe, 12...Joint pipe, 22...Sub-outer pipe, 24...Inlet, 26...Mixing chamber, 28,
30...discharge port, 46...discharge port.

Claims (1)

[Claims] 1. An outer tube 1 having one or more injection ports 24 opened in the peripheral wall and a mixing chamber 26 communicating with the injection ports near the inside thereof.
0, 12, 22, and a spool pipe 44 which has 46 discharge ports and communication holes 50 communicating from the inside to the outside, and which is internally housed in the outer pipe and is movable in the axial direction thereof. An outer flow path outlet 28 and an inner flow path outlet 30 are formed in the wall that partitions the mixing chamber 26 in the longitudinal direction with the communication hole 50 as a boundary during movement, and these outer flow path outlet 28 and inner flow path outlet The outlet 30 is formed to communicate with the mixing chamber 26 in the longitudinal direction bordering the injection hole 24, and when only the first liquid is fed into the spool pipe 44, the first liquid passes through the spool pipe 44. When the second liquid is force-fed from the discharge port 46 toward the tip between the first liquid, the outer tube, and the spool tube 44, the spool tube 44 is moved by the feeding pressure of the second liquid. Then, as the spool pipe 44 moves, the discharge port 46 is inserted into the outer pipe and closed, and at the same time, the first liquid into the spool pipe 44 is transferred to the mixing chamber 26 through the communication hole 50, and the second liquid is transferred into the mixing chamber 26 through the communication hole 50. The grout injection device is characterized in that the first liquid and the first liquid are each introduced into the mixing chamber 26 independently between the outer tube and the spool tube 44 and through the outer flow path outlet 28.