JPH0223628Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a grout injection control device that achieves improved injection precision at low flow rates, smaller size and lighter weight, etc. in grout injection for ground improvement.

For grout injection in dams and urban civil engineering, the single-path method shown in Figure 1 and the hole circulation method shown in Figure 2 are generally adopted, depending on the method of grouting pipe. In such cases, although not shown, an in-hole circulation system is adopted.

In the simple method shown in FIG. 1, the grout whose concentration has been adjusted by a mixer 1 is pumped by a metering pump 2, and is forced into the ground by an injection pipe 5 of a boring machine 4 via a supply pipe 3 made of a rubber hose. . 42 is a packer, and 43 is a grout hole. At this time, the flow rate and pressure of the grout sent from the pump 2 are detected by a flow rate detector 6 and an injection pressure detector 7, and each is converted into an electric signal by a converter, and the output is recorded in a recorder 8. It is also compared with the signal set by the flow rate and pressure regulator 9, and the opening degree of the control valve 10 is controlled using this comparison signal to return excess grout to the mixer 1 through the return pipe 11, thereby injecting it. It was designed to control the flow rate and pressure of the grout.

However, in such a single-path system, the control valve 1
The longer the supply pipe 3 made of a rubber hose that connects the injection pipe 5 and the supply pipe 3, the longer the supply pipe 3 becomes.
Cement settles and adheres inside. If the concentration of the cement milk is low and the amount injected into the ground from the supply pipe 3 is large, it will not be so great, but as the grout injection progresses and the process of pouring cement milk with a higher concentration gradually occurs, the amount returned from the return pipe 11 will increase. increases, the amount of water injected into the ground from the supply pipe 3 gradually decreases, and finally the flow velocity within the supply pipe 3 almost disappears, and the deposits within the control valve 10 and within the supply pipe 3 increase. Therefore, the injection flow rate and pressure in the ground cannot be accurately controlled, and as a result, pressure exceeding the injection pressure limit can cause abnormal displacement of the ground, causing structures such as dams to float or tilt. However, there were drawbacks such as troublesome maintenance and management of the device in case of failure due to clogging in the rubber hose or cleaning.

On the other hand, in the hole circulation system, as shown in FIG. 2, a return pipe 11 is connected from a hole 12 at the tip of the injection pipe 5, and a control valve 10 is interposed in the middle of the return pipe 11. be. According to this system, grout is constantly circulated through the supply pipe 3 and the return pipe 11 even when the injection amount is reduced, so that settling and adhesion of the grout in the pipe line is prevented. However, since the flow rate detector 6 and the injection pressure detector 7 are attached to the supply pipe 3, the actual injection amount and injection pressure in the injection pipe 5 cannot be detected accurately, and the opening degree of the control valve 10 cannot be controlled. There was also a problem that it became inaccurate.

The present invention was developed to solve the above-mentioned problems, and consists of an injection control section that integrates an injection amount detection section and an injection pressure detection section between the hole port and the injection pipe. be. Although it is desirable that the control valve is also located at the opening of the hole to form a unit, it is also possible to use a single-path system in which only the control valve is provided on the pump side.

Embodiments of the present invention will be described below with reference to the drawings. Note that the same parts as in FIGS. 1 and 2 are given the same reference numerals.

FIG. 3 is an explanatory diagram of the principle of the first embodiment of the present invention. In FIG. 3, an injection control section 14 in which a control valve 10, a control valve drive motor 13, an injection pressure detection section 7, and an injection amount detection section 6 are integrated into a unit faces a hole 12 of an injection pipe 5. It is provided. Therefore, in this example, a hole circulation system is adopted. More specifically, as shown in FIG. 4, the pump 2
The tip of the supply pipe 3 is connected to an inlet 15 of a three-way control valve 10, and a return pipe 11 is connected to a first outlet 16 of the control valve 10, so that the supply pipe 3 is returned to the mixer 1. It can be done. Second exit 1
7, the injection pressure detection section 7 and the injection amount detection section 6 are sequentially connected via the high pressure union 18. The injection amount detection unit 6 may be directly connected to the injection pipe 5 or may be connected to the injection pipe 5 via a rotary joint 19 .

Next, the control valve 10 and its driving motor 1
3 is explained in detail with reference to FIG.
Between the first and second cylindrical bodies 20 and 21 and between the second and third cylindrical bodies 21 and 22 of 0, there is a donut-shaped valve seat 25 with through holes 23 and 24 bored in the center of each.
26 is fixed. A first outlet 16 for connecting the return pipe 11 is provided on the side surface of the first cylindrical body 20, and an inlet 15 for connecting the supply pipe 3 is provided on the side surface of the second cylindrical body 21. A second outlet 17 opens at the lower end of the third cylindrical body 22, and is connected to the high pressure union 18. Said first
A flange body 27 is provided at the upper end of the cylinder body 20,
A valve shaft 29 passes through the center hole 28 of the flange body 27 in a fluid-tight manner. At the lower end of this valve shaft 29,
A cylindrical valve body 3 that moves forward and backward within the valve seats 25 and 26
0 is fixed.

The upper end of the valve shaft 29 protrudes from the flange body 27 and fits into the center hole of the feed gear 31. This feed gear 31 is linked via another feed gear 32 to a drive motor 13 that can be decelerated. Further, the valve shaft 29 has a converting portion 34 that converts the rotation of the feed gear 31 into vertical motion, and furthermore, a valve opening/closing cam 35 is fixed to the upper end of the valve shaft 29, and the side of this valve opening/closing cam 35 is fixed to the upper end of the valve shaft 29. Movable parts 36, 37 of limit switches 40, 41 for detecting upper and lower limit positions
is provided.

Next, the operation of the present invention will be explained.

In the cement concentration adjustment tank (not shown), 1
In order to accommodate changes in concentration at each stage, the ratio of water and cement is changed to obtain cement milk with a predetermined concentration, which is sent to mixer 1, where it is sucked by pump 2 and sent under pressure to feed pipe 3. .

Here, when the valve body 30 of the control valve 10 is in the solid line state in FIG. 5, almost all of the cement milk from the feed pipe 3 is sent to the injection pipe 5 side via the second outlet 17 and injected into the ground. be done. On the way to this injection pipe 5, the pressure is detected by the pressure detection section 7, the injection amount is detected by the injection amount detection section 6, and is recorded in the pressure flow recorder 8, and the pressure is set in advance by the pressure regulator 9. Compare with the set value. Then, a control signal is output so that the set pressure is always maintained.
This control signal causes the motor 13 to rotate forward or reverse, thereby rotating the feed gears 32 and 31. Then,
The valve shaft 29 moves up and down. The valve seat 2 is lowered by lowering the valve stem 29.
The 6 side is slightly closed, and the valve seat 25 side is slightly open. Therefore, the amount of injection from the second outlet 17 decreases, and the decreased amount is returned to the return pipe 11 from the first outlet 16. The lower the valve body 30 is, the more the injection amount decreases, and the return amount gradually increases. And the valve body 30
When the injection amount drops to the lowest end as shown by the chain line, the injection amount disappears and the entire amount is returned to the return pipe 11.

In the embodiment, as shown in FIG.
4 was installed vertically on a stand 38, but if the weight is large, it may be installed horizontally as shown in FIG. 6, and the injection pipe 5 may be connected at right angles.

In the embodiment described above, the control valve 10 is a three-way valve, but as shown in FIG. 7, it may be a two-way valve when provided in the middle of the return pipe 11.

In the embodiment described above, the injection pipe 5 was directly connected to the injection control section 14, but as shown in FIG. 8, it may be connected to the injection pipe 5 via a flexible pipe 39.

In the embodiments shown in FIGS. 3, 6, 7, and 8, the so-called hole return method was used.
As shown in FIG. 9, a single path system may be used; in this case, only the pressure detection section 7 and the injection amount detection section 6 are connected to the hole opening 1.
2 and the injection pipe 5.

The above explanations are mainly applied to large-scale works such as dam construction, but in the case of urban civil engineering works, the method shown in FIG. 10 is adopted. That is, the grout is made of A liquid,
Separate tanks 1a and 1b for liquids A and B, respectively.
, and is pumped by two pumps 2a, 2b from independent supply pipes 3a, 3b through independent injection pipes 5a, 5b, which are also like double pipes,
This is a method in which liquids A and B are discharged from the tips of these injection pipes 5a and 5b, and are mixed and hardened when injected into the ground. In this case as well, the injection control section 14, which is a unit of the injection pressure detection section 7 and the injection amount detection section 6, is provided between the hole 12 and the injection pipes 5a, 5b. A liquid that forms grout, if A is water glass, B liquid,
B is a mixture of a curing agent and an accelerator, and is usually mixed at a ratio of A liquid: B liquid = 1:1. Therefore, the injection amount detection section 6 is connected to the injection pipe 5a or 5.
Any of the flow rates b may be detected.
The total injection amount is then displayed and recorded by doubling the detected value. The injection pressure detection unit 7 also detects from either injection pipe 5a or 5b.

Note that if the ratio of liquid A and liquid B is other than 1:1, the ratio can be known in advance from the supply amount of the interlocking pumps 2a and 2b. By simply measuring the amount of one of the liquids injected, the total amount of injected liquid can be determined by a simple calculation. Of course, it is also possible to detect the injection amount of both the injection pipes 5a and 5b and add the same, and similarly, the pressure can be detected from both injection pipes 5a and 5b and displayed separately. May be recorded. Furthermore, when liquid B and B are composed of two or more types and are injected independently, the injection tube consisting of the double tube is made into a multi-tube of triple tube or more.

Since the present invention is configured as described above, the flow rate of the return pipe does not decrease even when the concentration of grout becomes high and the injection amount becomes low, so there is no clogging of the pipe, and there is no flow between the injection pipe and the hole opening. Since pressure and flow rate are detected, injection pressure and injection volume are extremely accurate. Moreover, since the control device is integrated into a unit, it can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a grout injection control device using a conventional simple method, FIG. 2 is an explanatory diagram of a hole circulation method, and FIG. 3 is an explanatory diagram of a first embodiment of a grout injection control device according to the present invention. Figure 4 is a detailed view of Figure 3, Figure 5 is a more detailed sectional view of the control valve, and Figure 6 is a detailed view of the control valve.
7, 8, 9 and 10 are explanatory diagrams of second, third, fourth, fifth and sixth embodiments of the present invention. 1... Mixer, 2... Pump, 3... Supply pipe, 4... Boring machine, 5... Injection pipe,
6... Injection amount detection section, 7... Injection pressure detection section, 8
...Flow rate pressure recorder, 9...Flow rate pressure regulator, 1
0... Control valve, 11... Return pipe, 12... Hole, 13... Motor, 14... Injection control section, 15
...Entrance, 16,17...Exit.

Claims (1)

[Scope of utility model registration request] The grout in the tank is pumped into the supply pipe, and the grout is injected into the ground from the hole through the injection pipe, with at least an injection pressure detection unit and the injection There is an injection control section in which a quantity detection section is integrated, and the injection control section includes a control valve consisting of a three-way valve, a supply pipe is connected to an inlet of the control valve, a return pipe is connected to a first outlet, and a return pipe is connected to a first outlet of the control valve. The injection pipe side is connected to each of the two outlets, and the opening degree of the control valve is controlled by a driving motor, and the motor is controlled by the outputs of a pressure detection section and an injection amount detection section. Grout injection control device.