JPH0328526B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION ``Industrial Field of Use'' The present invention relates to a chemical injection device, which is sometimes most suitable for compound injection in which instant setting grout and slow setting grout are alternately injected in the same process.

``Prior art'' Conventionally, a piston valve that opens and closes a discharge port for chemical liquids is installed in the grout monitor section at the tip of an injection pipe, or a spool valve that opens and closes a valve hole that introduces two types of chemical liquids into a mixing chamber and mixes them together. Injection is performed while opening and closing the discharge port and the valve hole by moving each valve body forward by the force-feeding pressure of the injected chemical solution, and retracting it by a return spring attached to the valve body when the force-feeding of the chemical solution is interrupted. Devices that do this are known.

``Problems to be Solved by the Invention'' As described above, in the conventional injection device, the pressure of the injected chemical solution causes the valve body to return and move against the elasticity of the spring. In addition to being limited by the elasticity of the spring, the opening and closing of the valve hole or discharge port must be performed by force feeding and interrupting the chemical solution, so the switching and injection operation of the chemical solution becomes discontinuous in complex injections, etc. When the valve body is moved forward to open the valve hole or discharge port and discharge the chemical liquid at a pressure of Opening and closing becomes unstable,
There were drawbacks such as the tendency to cause pulsations when pumping the chemical solution.

In addition, in conventional injection devices, the chemical liquid flows into the part where the return spring is attached, so the hardening of the inflowing chemical liquid causes the return spring to solidify and lose its normal spring function, resulting in uninterrupted injection work. There were also drawbacks that made it possible.

"Means for Solving the Problems" In order to solve the above-mentioned conventional problems, the present invention has the following features:
By opening and closing the valve hole using a valve body that is moved forward by a pressure fluid other than the chemical liquid and retracted by a return spring, the injection pressure of the chemical liquid can be returned without being limited by the elasticity of the spring. The present invention proposes a rational injection device that enables stable and continuous injection work without interrupting the pressure feeding of the chemical and prevents the return spring from solidifying due to the chemical solution.

``Embodiment'' Below, an explanation will be given of an embodiment of the present invention shown in the drawings. The figure shows the structure of the grout monitor section of the injection device according to the invention.
It has a triple tube configuration with a central tube C placed at the center of the interior, and by sequentially connecting the required number of outer tubes, inner tubes, and center tubes at the rear end of each tube, injection of a predetermined length can be performed. It is designed to form a tube.

The outer tube A has a plurality of tubular members such as a drill bit 1, a check valve body 2, a lower injection part body 3, a passage body 4, an upper injection part body 5, a joint pipe 6, etc., connected and integrated in a disassembly manner from the tip. It is configured. The inner pipe B is constructed by removably connecting and integrating valve pipes 7a and 7b and a joint pipe 8, which are integrally connected front and rear by partially overlapping each other inside the upper injection part body 5 of the outer pipe A. A protrusion 8' such as a radial protrusion or a perforated flange provided on the outer circumference of the joint pipe 8 is connected to the outer pipe A.
The sealing flanges 9a and 9b provided on the outer periphery of the valve pipes 7a and 7b are connected to the inner periphery of the upper injection body 5 of the outer tube A. It is fixed by closely supporting the surface.

Furthermore, the central tube C includes a tube body 10 whose tip is located within the rear end of the flow path body 4 of the outer tube A, a sealed tube 11 connected to the tip, and a tube having approximately the same outer diameter as the sealed tube 11 and located behind it. A radial projection provided on the outer periphery of the joint tube 13, which is integrally constructed from a rubber or synthetic resin sealing member 12 wrapped around the outer periphery of the tube body 10 and a joint tube 13 connected to the rear end of the tube body 10. Or, attach the protrusion 13' such as a perforated flange to the rear valve pipe 7 of the inner pipe B.
It is fixed to the center of the inner tube B by being clamped between the joint portion of the inner tube B and the joint tube 8.

a joint pipe 6 of the outer pipe A and an upper injection part body 5;
An outer flow path 14 with a predetermined gap is provided between the joint pipe 8 of the inner pipe B and the rear valve pipe 7b, and an inner flow path 15 with a predetermined gap is provided between the inner pipe B and the center pipe C. Each flow path 14, 15 is connected to each pipe A,
It communicates with an outer flow path and an inner flow path formed when connecting an outer pipe, an inner pipe, and a central pipe for connection to B and C, respectively.

The lower injection part body 3 and the upper injection part body 5 of the outer tube A are respectively provided with a plurality of discharge ports 16 and 17 made of elongated holes at predetermined intervals in the circumferential direction. Further, a mixing chamber 18 for a chemical solution is provided in the inner circumference of the upper injection part body 5 around the discharge port 17, and is surrounded by the valve pipes 7a, 7b and their sealing parts 9a, 9b.

In the overlapping portion of the valve pipes 7a and 7b of the inner pipe B, there is a detour 20 that communicates with the outer flow path 14 through a plurality of communication holes 19 formed around the rear valve pipe 7b.
is provided, and this detour 20 is connected to the rear valve pipe 7b.
The mixing chamber 1 is connected to the mixing chamber 1 through multiple valve holes 21 bored around the
It is connected to 8.

Further, an inner flow path 1 is provided around the front valve pipe 7a.
A plurality of valve holes 22 are bored through which the mixing chamber 18 and the mixing chamber 18 communicate with each other.

An annular valve plate 23 made of an elastic material such as rubber is wrapped around the outer periphery of the perforated portion of each valve hole 21, 22.

At the tip of the central tube C, a cylindrical valve plunger 24 with a closed tip seals the inner circumferential surface of the tube 11.
and is attached in close contact with the seal member 12 so as to be freely movable forward and backward in the axial direction. This valve plunger 24
The rear end is slidably and tightly fitted into the tip of the front valve pipe 7a of the inner tube B, and an inner flow path is formed between the rear end and the tube body 10 of the central tube C. A switching flow path 25 communicating with the outer tube A is provided, and a tip introduction portion 26 is provided between the outer tube A and the outer tube A from the front outer periphery to the front.
is formed.

Around the middle part of the valve plunger 24, when it is in the retracted position, it opens into the switching passage 25 and the tip introduction passage 26 to communicate with each other, and when it is in the forward position, it is closed by the sealing member 12. A plurality of valve holes 27 are provided. Further, the valve plunger 24 closes the valve hole 22 of the inner pipe B in its retracted position, and closes the valve hole 22 in its forward position.
It is configured to open the inner flow path 15 and the mixing chamber 18 to communicate with each other.

Furthermore, a piston-shaped head 24' with an O-ring is provided protruding from the tip of the valve plunger 24, and this head 24' is connected to a cylinder 28 provided in front of the head 24'.
It is closely inserted into the interior so that it can move forward and backward.

The cylinder 28 forms a plurality of passages 29 around it and is fixed to the center of the passage body 4 of the outer tube A, and a bearing 30 is attached to the tip thereof.

A return spring 31 such as a compression coil spring is installed between the bearing 30 and the head 24'.
A resilient force is applied to the valve plunger 24 through the head 24 in the backward direction.

A rocket-shaped plug valve 32 is inserted into the center hole 30' of the bearing 30, and the rear end thereof protrudes from the bearing 30 and has a plunger head 24 in a retracted position.
is held close to the tip of the

This plug valve 32 is temporarily held in a predetermined position by engaging an O-ring 34 attached to the inner periphery of the center hole 30' of the bearing 30 in a groove 33 formed around the middle portion of the plug valve 32. When the valve plunger 24 moves forward with a pressure greater than the restraining force of the O-ring 34, it is pressed by its head 24' to crush the O-ring 34 or cut its inner peripheral portion and protrude forward.

Therefore, the inside of the cylinder 28 is always sealed by a plunger head 24' with an O-ring at the rear end, and by a bearing 30 and a plug valve 32 at the tip to prevent chemicals from entering the inside. The internal return spring 31 can always exert its elastic force without being solidified by a chemical solution or the like to normally retreat the valve plunger 24.

In front of the plug valve 32, a piston valve 35 fitted into the lower injection part body 3 so as to be slidable back and forth is temporarily held.

This piston valve 35 is locked to the lower injection part body 3 by a shear pin 36 which can be cut with a predetermined shearing force in a retracted position that closes the lower discharge port 16 on its outer circumferential surface, and has a tip at its center. A channel 37 is provided which expands into a trumpet shape.

This flow path 37 is open so that fluid can freely flow when the plug valve 32 is temporarily fixed to the bearing 30, and when the plug valve 32 moves forward, its tip is tightly fitted. It's starting to close down.

Inside the check valve body 2, there is a valve hole 3 of a valve body 38.
A check valve 42 is installed in which the valve 9 is closed by a ball 41 pressed by a spring 40.

"Action of the Invention" When performing composite injection work using the grout monitor configured as described above, the outer pipe A, inner pipe B, and center pipe C are connected to the outer pipe, inner pipe, and center pipe, respectively. Connect the tubes and attach a triple tube swivel to the upper end to form an injection tube.

First, as shown in FIGS. 1 and 2, the inner flow path 1
5, while pumping drilling water under pressure, the injection pipe is rotated to drill a hole with the drill bit 1 at the tip, and the drilling is continued until a predetermined depth is reached while sequentially connecting the required number of connecting pipes.

In this case, since no fluid is forced into the outer flow path 14 and the center pipe C, the drilling water flows from the inner flow path 15 to the valve plunger 24 in the retracted position.
It flows into the tip introduction path 26 through the switching flow path 25 and valve hole 27 inside the cylinder 28, and further flows through the flow path 29 on the outer periphery of the cylinder 28 and the center flow path 37 of the piston valve 35 in the open state to the check valve 42. The ball 40 is then discharged from the tip of the drill bit 1 through the valve hole 39 while being retracted.

After excavating to a predetermined depth in this manner, injection is carried out while sequentially pulling up the injection pipe. For this injection, as shown in FIG. 3, first, a non-hardening pressure fluid such as water or air other than the chemical solution is fed into the central tube C, and the valve plunger 24 at the tip is pressurized and lowered to the head 24'. The plug valve 32 is pressed to protrude forward, and its tip is tightly fitted into the center passage 37 of the piston valve 35, thereby closing the tip passage to the drill bit 1.

Next, with the valve plunger 24 pressurized by the pressure fluid in the central pipe C, the outer flow path 14
An instant hardening agent (liquid B) such as a cement suspension is pumped into the inner channel 15, and a slow-setting chemical liquid (liquid A) is pumped into the inner channel 15.

The B liquid that has flowed down in the outer flow path 14 flows into the detour path 20 through the communication hole 19, and flows into the mixing chamber 18 through the valve hole 21, pushing aside the valve plate 23.

On the other hand, the A liquid flowing down the inner flow path 15 is transferred to the valve hole 2 which is opened by the advancement of the valve plunger 24'.
2, the liquid flows into the mixing chamber 18 by pushing aside the valve plate 23, mixes with the B liquid from the outer flow path 14, is discharged from the upper discharge port 17, and is injected into the gap between the surrounding ground and the injection pipe. It hardens in a short time and forms a patch car.

After the instantaneous injection process is completed in this manner, the feeding of the pressure fluid into the central pipe C is stopped, and the pressurization of the valve plunger 24 is thereby released.
As shown in the figure, the valve plunger 24 automatically retreats due to the elastic force of the return spring 31, closes the valve hole 22 of the mixing chamber 18 at its rear end, and opens the valve hole 27 to connect the switching flow path 25. Tip introduction channel 26
communicate.

As a result, the B liquid that is continuously being force-fed into the inner flow path 15 immediately flows into the tip introduction path 26 through the switching flow path 25 and the valve hole 27, and further flows into the front of the piston valve 35 from the flow path 29. Then, the piston valve 35 is pressurized to disconnect the shear pin 36, and the piston valve 35 is moved forward and downward.

Since the lower discharge port 16 is opened by the lowering of the piston valve 35, the A liquid is ejected from the discharge port 16 and injected into the surrounding ground. In this case, the packer effect caused by the previous instantaneous setting injection prevents liquid A from rising and escaping, making it possible to perform reliable penetration injection with liquid A.

Note that even if the area around the cylinder 28 is filled with liquid A, the rear end of the cylinder 28 is not connected to the plunger head 2.
4', and the tip is the bearing 30 and the plug valve 3
2, so that liquid A does not enter inside, and the return spring 31 can permanently perform its function.

After one step of instant setting and slow setting injection process is completed in this manner, the next step of injection is carried out in the same manner while sequentially pulling up the injection tube.

"Effects of the Invention" As described above, according to the present invention, a central tube with an open tip for pumping non-hardening pressure fluid is installed in the center of the injection tube, and the tip is closed on the outer periphery of the tip of the central tube. A cylindrical plunger is installed in a sealed manner so that it can move forward and backward, and a return spring that applies elastic force in the backward direction is attached to the plunger, and the valve hole of the chemical liquid flow path provided around the central pipe is attached by moving the plunger forward and backward. Since it is configured to open and close, the valve hole can be opened and closed regardless of the pressure feeding and stopping operations of the chemical solution, and the injection pressure of the chemical solution can be freely set without being restricted by a spring or the like. The opening/closing operation of the valve hole is reliable, allowing for smooth pressure feeding of the chemical solution, and also preventing the return spring from solidifying due to the chemical solution, and ensuring stable and continuous pressure feeding of the chemical solution without interruption when switching and injecting the chemical solution. This makes it possible to carry out injection construction.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing the structure of the rear end of the injection device of the present invention, FIG. 2 is a longitudinal side view showing the structure of the tip thereof, and FIG. 3 is the injection device of the invention during instantaneous injection. FIG. 4 is a vertical side view of the main part of the injection device of the present invention during loose injection. A...Outer tube, B...Inner tube, C...Center tube, 1...
...Drill bit, 2...Check valve body, 3...Lower injection part body, 4...Flow path body, 5...Upper injection part body, 6...Joint member, 7a, 7b...
Valve pipe, 8...Joint member, 9a, 9b...Valve pipe sealed portion, 10...Pipe body, 11...Sealed tube, 1
2... Seal member, 13'... Joint member, 13...
...Protrusion, 14...Outer flow path, 15...Inner flow path, 16
...Lower outlet, 17...Upper outlet, 18...
Mixing chamber, 19...Communication hole, 20...Detour, 21
... Valve hole (upper), 22 ... Valve hole (lower), 23...
...Valve plate, 24...Valve plunger, 24'...
Head, 25...Switching channel, 26...Tip introduction path, 27...Valve hole, 28...Cylinder, 29...
Channel, 30... Bearing, 30'... Center hole, 31...
... Return spring, 32 ... Plug valve, 33 ... Concave groove, 34 ... O ring, 35 ... Piston valve, 36 ... Shear pin, 37 ... Channel, 38 ...
...Valve body, 39...Valve hole, 40...Ball, 41...
...Spring, 42...Check valve.

Claims (1)

[Scope of Claims] 1. A central tube with an open tip for pumping non-hardening pressure fluid is installed in the center of the injection tube, and a cylindrical valve with a closed tip is provided around the outer periphery of the tip of the central tube. The plunger is attached in a sealed manner so as to move forward and backward, and the valve plunger is configured to open and close a valve hole in a chemical fluid flow path provided around the central pipe by forward and backward movement of the valve plunger, and the tip of the valve plunger is installed in the front part thereof. The cylinder is fitted in a sealed manner so as to be freely movable and retractable, and the cylinder is provided with a bearing at its tip, and a plug is held in the center hole of the bearing so as to be able to protrude forward by the forward force of the valve plunger. A chemical liquid injector characterized in that a return spring is installed in the cylinder between the valve plunger tip and the bearing to apply an elastic force to the tip of the valve plunger in a backward direction. 2. A piston valve is provided at the front of the cylinder, which is held in the outer tube so as to be able to move forward with a predetermined pressing force, and opens the injection port provided in the outer tube when the piston valve moves forward. 2. The chemical liquid injection device according to claim 1, characterized in that the chemical liquid injection device is provided at the center with an excavation water channel that is inserted and closed. 3. The chemical liquid flow path includes an inner flow path formed between the center tube and an inner tube provided around it, an outer flow path formed between the inner tube and the outer tube, and a flow path from the outer periphery of the front half of the valve plunger to the piston. 2. The chemical liquid injector according to claim 2, further comprising a tip introduction path formed on the inner periphery of the outer tube toward the tip of the valve. 4 The rear end of the valve plunger is slidably inserted into the inner periphery of the inner flow path of the tip of the inner tube, and the inner periphery is inserted between the inner periphery of the valve plunger and the outer periphery of the center tube. 4. The chemical liquid injection device according to claim 3, further comprising a switching introduction path communicating with the flow path. 5 The valve hole is provided in the middle part of the valve plunger,
When the valve plunger is in the retracted position, it is opened so that the switching introduction passage and the tip introduction passage communicate with each other, and when the valve plunger is in the forward position, it is closed by a closing member provided on the outer periphery of the tip of the central tube. 5. A liquid drug injection device according to claim 4, characterized in that: 6. The liquid drug injection device according to claim 5, characterized in that a mixing chamber communicating with an injection port provided in the outer tube is provided between the tip of the inner tube and the outer tube surrounding the tip. . 7. A valve hole is provided at the distal end of the inner pipe to communicate with the mixing chamber, and is closed at the rear end when the valve plunger is in the retracted position, and is closed between the inner flow path and the mixing chamber when the valve plunger is in the forward position. 7. The drug solution injector according to claim 6, wherein the drug solution injector is configured to communicate with the drug solution injector. 8. The chemical liquid injector according to claim 7, wherein the inner tube is provided with a detour that communicates with the outer flow path and communicates with the mixing chamber via a valve hole.