JPH0411687B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a device for injecting a chemical solution for soil improvement, and particularly to its tip device.

[Technical background of the invention]

In recent years, as described in Japanese Patent Publication No. 58-30966,
The development and improvement of so-called composite injection methods in which fast-setting chemical solutions and slow-setting chemical solutions are used together has been actively carried out, and some of them have been put into practical use. However, although double pipes are mainly used, with the device described in the above publication being a typical example,
All of these methods have problems with reliability of operation and switching of chemical solutions within the injection tube. On the other hand, as in the invention of Japanese Patent Application No. 55-102201, a three-channel pipe is used to inject an instant-setting drug solution from the upper part and a slow-setting drug solution from the lower part. By using such a three-channel pipe, both fast-setting and slow-setting drugs can be injected at the same time, and there is no need to switch between drugs when injecting drugs selectively or alternately. This has an advantage that the double pipe system does not have.

[Purpose of the invention]

It is an object of the present invention to provide an injection device that is reliable in operation and relatively simple in structure, taking into account the advantages of the three-channel pipe described above.

[Structure of the invention]

To achieve this object, the present invention provides a spool valve in a first inlet portion of an outer tube in which a first inlet on the proximal side and a second inlet on the distal side are formed spaced apart in the depth direction. movably internally, three flow paths are configured independently up to the first injection port, the two flow paths are communicated with the first injection port, and one of the two flow paths is connected to the first injection port. When the liquid is forced into the channel, the spool valve is moved forward by the pressure, and each liquid passing through the two channels is poured out from the first injection port while merging, and the outer pipe A switching valve that closes the second inlet during normal operation and opens the second inlet when moving is installed in the second inlet portion of the
A blocking valve is disposed between the tip surface of the spool valve and the inlet of the switching valve that is connected to the spout at the tip, and the other channels other than the two channels are connected to the second inlet beyond the first inlet.
The blocking valve is in contact with the spool valve and opens the inlet of the switching valve when the spool valve is not moved, and the blocking valve is in a position that opens the inlet of the switching valve when the spool valve is not moved. The flow of liquid that is pushed out to close the base end of the switching valve and is supplied to the other flow path is guided to the second injection port by pushing down the switching valve via the blocking valve by the feeding pressure of the liquid. It is characterized by the following.

[Specific examples of the invention]

The present invention will be explained in more detail below with reference to specific examples shown in the drawings.

Figures 1 to 6 show the structure of the device of the present invention in the order of the construction process.
3 shows the step of injecting the slow-setting liquid _GL from the second injection port 20, and FIG. 4 shows the step-up step. Figure 5 shows the step of injecting the slow-setting chemical solution after the step-up, and Figure 6 shows the process of injecting the slow-setting chemical solution after the step-up. The steps for cleaning the inside are shown below.

Please note that the drawing shows only the tip device part.
A main body tube made of, for example, a triple tube is provided at this base, and is further connected to a swivel.

In the drawings, reference numeral 10 is a first outer tube, 12 is a second outer tube,
Reference numeral 14 denotes a tip tube having a bit 16 at its tip, which is successively screwed and connected to the tip side. A first injection port 18 is formed in the first outer tube 10 to penetrate in the radial direction and is formed in a single form or in a plurality in the circumferential direction (illustrated example). The inlet part is configured. In addition, the second outer tube 12 includes
A second injection port 20 is formed in the radial direction at intervals in the depth direction with respect to the first injection port 18 , and is formed in a single or plurality (as illustrated) in the circumferential direction. The second inlet portion of the outer tube is constituted by the vicinity.

On the other hand, inside the first outer tube 10, there is a bottomed valve seat portion 22.
A and a spool valve 22 having a joint pipe portion 22b integrated with the joint pipe portion 22b by screwing are movably housed inside the spool valve 22. Also, inside the first outer tube 10, a middle joint 2 is provided.
4 is integrated with this by screwing, and the first outer tube 10
are concentrically provided with a gap between the base and the joint tube portion 22b. In this way, the base of the joint pipe part 22b is inserted into the (most) inner pipe of the main body pipe (not shown), and the middle joint 24 is fitted into the middle (middle) pipe, so that the material is fed through the inner pipe. Liquid A is in the joint pipe part 2
B liquid enters the A liquid path 26 in 2b, passes through the gap between the inner tube and the middle, enters the B flow path 28 in the gap between the joint tube part 22b and the middle joint 24, and further flows between the outer tube and the middle of the main body tube. Perforation water W or slow-setting chemical solution passing through the gap with the pipe
G _L is guided to the C channel 30 between the middle joint 24 and the base of the first outer tube 10 .

When liquid A is fed, after pushing down the check valve 32 against the biasing force of the spring 34, the liquid A is fed to the valve seat portion 2.
Liquid B is discharged from a plurality of discharge ports 36 formed in 2a to a mixing chamber 38 formed by a gap between the first outer pipe 10 and the spool valve 22 behind the first injection port 18, and the B liquid is Sometimes, the joint pipe part 2
The liquid is discharged into the mixing chamber 38 while pushing down the entire spool valve 22 through the shoulder portion of the spool valve 2b. And A,
After both liquids B are countercurrently mixed in the mixing chamber 38, they are transferred to the first injection port 18 as an instant-setting chemical liquid Gs.
It is poured out into the surrounding ground.

On the other hand, a stop ring 40 is provided to be regulated by the distal end surface of the first outer tube 10 and the stepped portion of the inner surface of the second outer tube 12. A blockage valve 42 with a conical tip is provided inside the stop ring 40, and since an O-ring 44 is initially provided on the stop valve 42, it will not slip out forward from the stop ring 40. Spool valve 2
It is arranged adjacent to the distal end surface of No. 2. Further, in the inner thickness portion of the first outer tube 10 and the stop ring 40, a plurality of communication holes 46, 4 forming a C flow path are provided in parallel with the axis.
8 is formed, and as a result, the drilling water W or the slow-setting chemical liquid G _L is guided from the C channel 30 through the communication holes 46 and 48 to the front of the stop ring 40 .

50 is the discharge from the second injection port 20 and the jet port 58
This is a switching valve for switching between discharge from and from the pump, and is movably installed inside the second outer tube 12 while being biased by a spring 52. The switching valve 50 has a distal end whose outer surface matches the inner diameter of the second outer tube 12,
The outer surface of the proximal end is smaller than the inner diameter of the second outer tube 12, thus forming an annular path 54 between it and the second outer tube 12. When drilling a hole or injecting an instant-setting chemical, the spring 52 operates the switching valve 50 as shown in FIGS. 1, 2, and 4.
is biased toward the base side, the switching valve 50 closes the second injection port 20, and when injecting the slow-setting chemical solution and cleaning, the switching valve 50 closes the second injection port 20, and when the slow-setting chemical solution is injected and washed, the switching valve 50 closes the second injection port 20, and the switching valve 50 closes the second injection port 20, as shown in FIGS. 3, 5, and 6. Then, the switching valve 50 is pushed down toward the distal end side via the blocking valve 42. For related purposes, the second injection port 20
Open. Furthermore, in the state shown in FIG. 1, the distal end of the blockage valve 42 is inserted with some play into the proximal opening constituting the inflow port 50a of the switching valve 50, and the blockage valve 42 is inserted from the stop ring 40. After being pushed out (FIGS. 2 to 6), the blocking valve 42 becomes the switching valve 50.
The proximal opening of the proximal opening is tightly fitted and occluded.

The device configured as described above operates as follows.

First, while applying rotational force and pressure force to the injection tube,
As shown in FIG. 1, drilling water W is supplied, passed through the C channel 30, the communication holes 46 and 48, and passed between the blockage valve 42 and the proximal opening serving as the inlet of the switching valve 50. It is guided into the inner passage 56 in the switching valve 50, and is ejected forward from the ejection port 58, while drilling to a predetermined depth.

Once the specified depth is reached, as shown in Figure 2,
Both A and B liquids are supplied to the A liquid path 26 and the B liquid path 28, respectively, and the spool valve 2 is controlled by the feeding pressure of the B liquid.
2, the instant-setting chemical Gs is injected from the first injection port 18 by merging and mixing in the mixing chamber 38. At this time, as the spool valve 22 is pushed down, the closing valve 42 comes out of the stop ring 40 and tightly fits into the proximal opening of the annular valve 50 to close it.

Next, without moving the injection tube, at the same position, the loosely set chemical solution G _L , which has been merged in advance with a Y-shaped tube in front of the swivel, is introduced into the C channel 30 at the same position, and this is passed through the communication holes 46 and 48. Pass it through. Chemical solution G _L exited from ring stopper 40
As the inlet of the switching valve 50 is blocked by the blocking valve 42, there is no place for it to go, so pressure is applied to the protrusion at the tip of the switching valve 50 and the proximal face of the blocking valve 42, and the switching valve 50 is closed. While pressing down, ring road 5
4 and is injected from the second injection port 20.

Next, the injection tube is stepped up to a predetermined length, and in the next step, the instant-setting drug Gs is injected by the same operation as shown in FIG. 4, and the slow-setting drug G _L is injected by the same operation as shown in FIG. injection is made.

Thereafter, the steps are raised one after another, and the chemical solutions Gs and G _L are injected at each step. Before the final removal, cleaning water W' is supplied to the A, B, and C channels 26, 28, and 30. 1 and 2nd inlet 18, 2
Clean each channel while dispensing from 0.

Note that the spring 52 is used to return the switching valve 50 to the base side for the transition from the slow-setting chemical liquid injection process (FIG. 3) to the quick-setting chemical liquid injection process (FIG. 4).
However, after the cleaning process (FIG. 6), even if the spring 52 returns the switching valve 50 to the base side, the blocking valve 42, which has been advanced from the stop ring 40, is returned to the state shown in FIG. It does not return, but only returns to the state shown in FIG. Therefore, after finishing the injection work at one location, when starting injection at another location, it is necessary to disassemble the injection pipe and return the blocking valve 42 into the stop ring 40. By this,
The drilling process shown in FIG. 1 can now begin.

On the other hand, as shown in FIG. 7, an inlet 50'a may be formed in the peripheral wall of the switching valve 50', and this may be closed or opened by a cap-shaped closure valve 42'.

〔Effect of the invention〕

As described above, the present invention includes the spool valve 22 in the first inlet portion and the switching valve 50 in the second inlet portion.
A blockage valve 42 is provided adjacent to the spool valve 22, and the blockage valve 42 is moved by the movement of the spool valve 22, thereby switching the perforation waterway to a slow-binding chemical liquid channel. This, combined with the three-channel structure, ensures reliable operation and eliminates the need to replace the fluid in the channel with another liquid, as is the case with double pipes, allowing you to directly achieve the desired injection form. There are benefits that can be achieved.

[Brief explanation of drawings]

The drawings show the apparatus and operation of the present invention in the order of construction: Figure 1 shows the process during drilling, Figure 2 shows the process during instant-setting chemical injection, Figure 3 shows the process during slow-setting chemical injection, and Figure 4 shows the step-up process. FIG. 5 is a longitudinal cross-sectional view showing the state during instant-setting drug solution injection after step-up, slow-setting drug solution injection after step-up, and FIG. 6 is a longitudinal sectional view showing the state during cleaning. FIG. 7 is a partial view of a modification of the device of the present invention. FIG. W...Drilling water, W'...Washing water, Gs...Snap-setting chemical solution, G _L ...Low-setting chemical solution, 10, 12...Outer tube,
18...first injection port, 20...second injection port, 22
... Spool valve, 26 ... A flow path, 28 ... B flow path, 30 ... C flow path, 38 ... Mixing chamber, 40 ...
Stop ring, 42...Occupation valve, 46, 48...Communication hole,
50, 50'...Switching valve, 50a, 50'a...Inlet, 54...Annular path, 58...Ejection port.

Claims (1)

[Claims] 1. A spool valve is movably installed inside the first inlet portion of the outer tube in which a first inlet on the base side and a second inlet on the distal side are formed at intervals in the depth direction, and Three flow paths are configured independently up to the injection port, and when the two flow paths are communicated with the first injection port, and when the liquid is force-fed to one of the two flow paths, the pressure is applied. The spool valve is configured to move forward, and the liquids passing through the two channels are poured out from the first inlet while merging, and the second inlet of the outer tube is normally connected to the second inlet. A switching valve that closes the second injection port and opens the second injection port during movement is installed, and the blocking valve is disposed between the tip surface of the spool valve and the inlet of the switching valve that connects to the spout at the tip. The channels other than the second channel can freely communicate with the second inlet and the inlet of the switching valve beyond the first inlet portion, and the blocking valve is in contact with the spool valve when the spool valve is not moved. When the spool valve moves, it is pushed out to the tip and closes the inlet of the switching valve, thereby controlling the flow of liquid supplied to the other flow path. A special feature of this chemical liquid injection device is that supply pressure pushes down a switching valve via a blockage valve and guides the liquid to the second injection port.