JPH07109092B2 - Grout injection controller - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a grout injection control device capable of finely adjusting a grout injection amount in dam construction and the like and capable of efficiently performing an operation.

2. Description of the Related Art In order to improve the ground in dam construction, grout mixed with cement or bentonite is injected into the ground. In this case, conventionally, as shown in FIG.
The grout that is constantly stirred in the grout pump 2
Sent to the three-way valve 3 by means of a flow rate detector 4 and pressure detector 5
The signals of the flow rate and pressure detected by are sent to the flow rate pressure control device 6, the three-way valve 3 is operated so that the detected values approach the preset flow rate and pressure, and the excess grout is returned to the return line (return line). The grout was being injected into the ground 8 while returning from the (pipe line) 7 to the storage tank 1. 9 is a suction pipe line, 10 is a supply pipe line, 11 is an injection pipe line, 12 is an injection port, 3a is an inflow port of the three-way valve 3, 3b and 3c are discharge ports, and 16 is an injection pipe.

[Problems to be Solved by the Invention]

However, in the conventional injection control device described above, for example, the fourth
As shown in the figure, when the storage tank 1 is located higher than the injection port 12 and the pressure head is added due to the difference in height, and the return pressure is higher than the set injection pressure, even if an attempt is made to control the set injection pressure Since the target injection pressure is higher than the set injection pressure, it cannot be injected at the set injection pressure unless the storage tank 1 is moved downward to reduce the return pressure, and the storage tank is moved every time the injection location changes. There is a problem in that the work is inefficient because of the inconvenience that must be made.

[Means for Solving the Problems]

The present invention solves the above problems, and even if the return pressure is higher than the set injection pressure, the injection can be performed at the set injection pressure without moving the storage tank, and fine pressure adjustment can be performed as compared with the conventional case. It is an object of the present invention to provide a possible injection control device, and the grout injection control device of the present invention in accordance with this object is to control the flow rate and pressure of the grout in the storage tank through a grout pump and a three-way valve. In a grout injection control device that controls and injects excess grout while returning to the storage tank, an accumulator or an air chamber is provided between the three-way valve and the injection port, and injection is performed while controlling the injection pressure. It is characterized by having done.

[Action]

In the present invention, the accumulator or the air chamber is provided between the three-way valve and the injection port, and the injection is performed while controlling the injection pressure. Therefore, when the set pressure of the injection grout is a slight pressure, the three-way to the injection port is set. It functions to buffer and adjust the pressure pulsation caused by repeated slight opening and closing of the valve outlet. It also functions to buffer the pressure pulsation by the grout pump and smooth not only the pressure but also the flow rate.

【Example】

Hereinafter, the present invention will be described in more detail by way of examples with reference to the drawings. FIG. 1 is a system diagram showing a first example of the grout injection control device of the present invention. In the reference numerals shown in FIG. 1, those having the same functions as those shown in FIG. It is attached with a code. Reference numeral 1 is a storage tank for constantly storing the grout while stirring, 9 is a suction pipe line connecting the storage tank 1 and the grout pump 2, 10 is a three-way valve, preferably a sealable three-way valve shown in Examples described later. A supply line connecting the inflow port 13a of 13 and the discharge port of the grout pump 2, 7 is a return line for returning the grout discharged from the discharge port 13b of the three-way valve 13 to the storage tank 1, and 11 is the three-way valve 13
Is an injection conduit connected to the discharge port 13c of the. The injection line 11 is connected to the injection port of an injection pipe 16 installed in the borehole in the ground, and the injection line 11 has an accumulator.
15, a flow rate detector 4, and a pressure detector 5 are provided. In the flow rate pressure control device 14, the flow rate and pressure signals detected by the flow rate detector 4 and the pressure detector 5 are compared with the preset flow rate and pressure set values, and the detected values are approached. The three-way valve 13 is operated. Here, when the set pressure of the injection grout is a slight pressure, the accumulator 15 functions so as to buffer and adjust the pressure pulsation caused by repeated opening and closing of the discharge port 13c. Further, the accumulator 15 not only works effectively when the set pressure is a slight pressure, but also has a function of buffering the pressure pulsation by the grout pump 2 and smoothing not only the pressure but also the flow rate. In the above-described grout injection control device, when the injection pressure is higher than the sum of the lift due to the pressure loss of the return pipe 7 and the lift due to the height difference between the inlet 12 and the storage tank 1, the discharge outlet
The opening of the 13c side flow path is larger than the current one, that is, the discharge port 1
By setting the opening degree of the 3b side flow passage to be smaller than the current one, it is possible to control the flow rate and the pressure to be set, and the injection pressure is increased by the head loss due to the pressure loss of the return line 7, the injection port 12 and the storage tank 1. If it is lower than the sum of heads due to height difference, or if the ground injection resistance is low and the grout is injected by gravity flow or more, the opening of the discharge port 13c side flow path is smaller than the current state, That is, the flow path and pressure of the grout to be injected can be controlled to the set values by increasing the opening degree of the flow path on the discharge port 13b side from the current state. Further, in the case of slight pressure injection, it is performed by repeatedly opening and closing the discharge port 13c as described above.
Due to the pressure buffering effect of, it is possible to inject with less pulsation. FIG. 2 is a system diagram of a second example of the grout injection control device of the present invention in which an air chamber 17 is provided in place of the accumulator 15, and the air chamber 17 is an injection pipe line 11.
It is provided in. 24 and 24 'are upper and lower limit level switches attached to the air chamber 17, 18 is a pressure air source such as a compressor for supplying air to the air chamber 17 through a pipe 25, and 19 is a pressure air source provided in the pipe 25. A pressure adjusting valve that adjusts the pressure air from 18 to a desired air pressure, 20 is an air operating valve provided between the pressure adjusting valve 19 of the pipe 25 and the air chamber 17, and 21 is an electromagnetic valve that opens and closes the air operating valve 20. valve,
Reference numeral 22 is a check valve provided between the air operation valve 20 of the pipe 25 and the air chamber 17. When the lower limit level switch 24 'attached to the air chamber 17 is activated, a signal is sent to the control unit 23, the solenoid valve 21 is operated to close the air operated valve 20 to stop the air supply, and the upper limit level switch 24 is activated. A signal is sent to the control unit 23 to operate the solenoid valve 21 to open the air operation valve 20 to supply air. Thus, the volume of the air chamber 17 is prevented from being melted into the grout to prevent the volume from decreasing, and the volume does not change within a certain range. The operation of the grout injection control device has been described with reference to the device of FIG. 1 and thus will not be described. However, in addition to the function and effect of the device of FIG. 1, the air pressure in the air chamber 17 can be maintained at a desired air pressure. There is an effect that grout can be injected by adjusting a slight pressure with little pressure pulsation. By the way, the three-way valve used in the past was a non-sealing type that could not be completely sealed due to its structure such as abrasion due to grout, etc., over a long period of use. Therefore, it is difficult to fine-tune the pressure and flow rate, which makes it unsuitable for dam grouts that require strict injection control (injection pressure and flow rate control), unlike in urban civil engineering. there were. Moreover, as described above, when the storage tank is located higher than the inlet and the pressure head is applied to the three-way valve, it is even more difficult to finely adjust the pressure and the flow rate if it is an unsealed type. I was tightening. Therefore, as the three-way valve 13 used in the grout injection control device of the present invention, it is suitable to use a sealable three-way valve A described below. Since the sealable three-way valve A described below can be used not only for grout but also for other fluids and can be used as a mixing valve,
I will explain in such a form. In FIG. 5, the sealable three-way valve A is a valve case body.
26, a cover plate 27 attached to one side thereof, and a diversion tube 28 attached to the other side, in a valve case 29, which has a smooth surface on one side and is concentrically formed with two corresponding arcs. The valve shown in detail in FIG. 6 provided with non-penetrating valve seat holes 30 and 30 'and two flow dividing holes 30a and 30a' communicating with the two valve seat holes 30 and 30 ', respectively. It has a seat 31 and a smooth surface in contact with the smooth surface of the valve seat 31, and corresponds to the valve seat holes 30 and 30 ', and has a length longer than the valve seat holes 30 and 30' (smaller opening). However, the valve element 33 shown in FIG. 7 having an arc-shaped through hole 32 is housed with the respective smooth surfaces in contact with each other.
The rotary shaft 34 is mounted so that it can be freely rotated in either the left or right direction. More specifically, the valve seat 31 is fixed by being sandwiched between a protrusion 26a protruding along the inner circumference of the valve case main body 26 and a distribution pipe 28 attached to the valve case main body 26 by means such as screwing. The flow dividing cylinder 28 has a flow dividing chamber 35, 35 'communicating with the flow dividing holes 30a, 30a' and discharge ports 36, 3 communicating with the flow dividing chamber 35, 35 '.
6'is provided. An inflow chamber 37 is formed in the valve case body 26,
An inflow port 38 is provided so as to communicate with 37, and a distal end of a rotary shaft 34 is inserted into a long recess 39 provided in the valve body 33. The rotary shaft 34 is rotatably fixed in position by a bearing 40 fitted on the outside thereof and a nut 41 screwed on the inside of the case body 26. Incidentally, 34a is a flange portion projecting on the outer periphery of the rotary shaft 34, and 42 is a notch portion provided parallel to the end surface of the nut 41.
It is a lock bolt that penetrates the part of 41a and is screwed,
The cover plate 27 is also attached to the case main body 26 by means of screwing or the like as in the case of the distribution pipe. The sealable three-way valve configured as described above has an inlet 38 and an outlet.
By connecting a pipe to 36, 36 'and sending a fluid from the inflow port 38 and rotating the rotary shaft 34 by a drive source (not shown), the flow rate of the fluid discharged from the discharge ports 36, 36' can be controlled at will. Alternatively, the discharge amount from one discharge port can be set to zero. In this sense, it is called a sealable three-way valve. Conversely, if different fluids are made to flow in from the discharge ports 36, 36 ',
The intended amount of fluid is discharged from the inflow port, and when a continuous mixer is connected to the inflow port, the fluid is kneaded and discharged, so that it can also be used as a fluid mixing valve. The arc-shaped through-hole 32 of the valve element 33 may be a plurality of through-holes 32 ″, 32 ″ ... (illustrated by dotted lines) discharged in an arc shape at intervals, and instead of the valve element 33, Arcuate notch 3 shown
You may use the valve body 33 'which formed 2'. Also the rotating shaft 3
4 is replaced with bearing 40 and nut 41, and rotating shaft 34
You may make it press-fix by the spring fitted on. The valve can be made of metal such as stainless steel, but if the valve body and the valve seat are made of ceramics, the durability will be further improved. In this case, as shown by the dotted line in FIG. 7, in the valve body 33, a reinforcing plate made of steel or the like provided with through holes 43 'or 43 "of the same shape communicating with the through holes 32 or 32".
If 43 is fixed by using an adhesive or the like, the valve body will be excellent in wear resistance and mechanical strength, and will be more durable. The above-mentioned valve can be used as a diversion valve or a mixing valve, but since it is a sealable type and has excellent durability, it is very suitable to be used in the sealable three-way valve of the present invention. That is, the discharge port 36 or 36 'is connected to the return line 7 or the injection line 11, and the inflow port 38 is connected to the supply line 10 for use.

【The invention's effect】

Since the present invention is configured as described above, even if the return pressure is higher than the set injection pressure, the injection can be performed at the set injection pressure without moving the storage tank.
Change the installation location of the storage tank each time the injection location changes,
Moreover, not only the cost of moving the injection equipment can be reduced, but also the time required for the movement can be shortened so that the work can be performed efficiently and economically, and the grout is injected while maintaining a slight pressure. It also has the advantage of being possible.

[Brief description of drawings]

FIG. 1 is a system diagram of a first example of a grout injection control device of the present invention, FIG. 2 is a system diagram of a second example, FIG. 3 is a system diagram of a conventional device example, and FIG. The schematic diagram shown in FIG. 5, FIG. 5 is a cross-sectional view of the sealable three-way valve, and FIGS. 6 (A), (B), and (C).
Is a front view, a side sectional view, and a rear view of an example of a valve seat, FIGS. 7A and 7B are front views and side sectional views of an example of a valve body, and FIG. 8 is a front view of an example of a valve body. 1 ... storage tank, 2 ... grout pump, 12 ... inlet,
13 …… 3-way valve, 15 …… Accumulator, 17 …… Air chamber, A …… Sealable type 3-way valve.

Claims (1)

[Claims] 1. A grout in a storage tank is injected through a grout pump and a three-way valve to control the flow rate and pressure to inject the grout into the ground from the inlet of the injection pipe, and the excess grout is returned to the storage tank. In the grout injection control device for injecting while, an accumulator or an air chamber is provided between the three-way valve and the injection port to inject while controlling the injection pressure.