JPS6365769B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cement milk injection device for soft ground improvement work.

(Prior art) A conventional cement milk injection device for soft ground improvement work is explained with reference to Fig. 1. A is a processing machine that penetrates into the ground and injects cement milk, and the processing machine a is connected to a winch b. It is attached to the tip of the wound wire c, and when the winch b is driven in the winding or unwinding direction, the processing machine a moves up and down.

In addition, d is another wire attached to the processing machine a, the other end of the wire d is wound around a drum e, and a rotary encoder f is attached to the rotating shaft of the drum e.
are directly connected to each other, and when the processing machine a moves up and down and the drum e rotates forward and backward, the rotational speed of the drum e is detected by a rotary encoder f.

Further, the output terminal of the rotary encoder f is connected to the controller h via the F/V converter g, and the output signal of the rotary encoder f is sent to the controller h as a set signal.

Further, i is a leverable motor for adjusting the swash plate tilting angle that receives a control signal from the controller h, and j is a leverable motor for adjusting the swash plate tilting angle.The swash plate tilting angle is adjusted by the same leverable motor i. A hydraulic pump, k is a grout pump driving hydraulic motor driven by pressure oil from the hydraulic pump j, l is a grout pump driven by the grout pump driving hydraulic motor k, and the grout pump l is driven. , cement milk in tank m is passed through electromagnetic flowmeter n and processing machine a.
It is now being injected underground through the

Next, the operation of the cement milk injection device for soft ground improvement work shown in FIG. 1 will be explained. Driving winch b to raise processing machine a,
Drive the grout pump l to pump the cement milk in the tank m → electromagnetic flowmeter n →
Inject into the ground via treatment machine a. At this time, the rising speed of the processing machine a is detected by the rotary encoder f, and the rising speed detection signal obtained at that time is sent as a set signal to the controller h via the F/V converter g. Compare the cement milk flow rate signal sent from n and find the difference between them, and send this as a control signal to the reversible motor i for adjusting the tilting angle of the swash plate. By adjusting the tilting angle of the swash plate of the reversible motor i, the flow rate of pressure oil sent from the hydraulic pump j to the grout pump driving hydraulic motor k, and by changing the rotation speed of the grout pump l, Cement milk at a flow rate proportional to the rising speed of a is injected into the ground through tank m, grout pump l, electromagnetic flow meter n, and processor a.

(Problems to be Solved by the Invention) In the conventional cement milk injection device for soft ground improvement work shown in FIG. At this time, even if the grout pump l is started, it takes more than ten seconds for the cement milk to start being discharged from the tip of the treatment machine a, so during this time, the cement milk is not injected into the ground, and the An uninjected portion of cement milk occurs. ()
In addition, the time constant of the flow rate control system of hydraulic pump j is large, so the amount of cement milk injected into the ground is controlled by
It is difficult to follow the fluctuations in the rising speed of If it were to be made to follow this, an expensive servo valve would have to be used, which would complicate maintenance and be prone to breakdowns. () Also, there is pulsation in the grout pump l, which causes a large disturbance in the cement milk flow rate detection signal (feedback signal) sent from the electromagnetic flowmeter n to the controller h. Therefore, there is a problem in that cumulative errors occur between the time when cement milk injection starts and the time when the injection ends, making it impossible to inject cement milk into the ground with high precision.

The present invention has been proposed in view of the above-mentioned problems, and its objective is to prevent the formation of uninjected portions of cement milk in the ground. It is possible to eliminate unstable operations such as hunting phenomenon that tend to occur in transient response control. Cement milk can be injected underground with high precision. Another object of the present invention is to provide a cement milk injection device for soft ground improvement work that can eliminate the need for an expensive servo valve, facilitate maintenance, and eliminate failures that occur in the servo valve part. .

(Means for Solving the Problems) In order to achieve the above object, the cement milk injection device for soft ground improvement work of the present invention includes a processing machine 28 that can be raised and lowered to penetrate into the ground and inject cement milk; A grout pump device 20 that injects cement milk underground through the treatment device 28 when the treatment device 28 is raised, and an injection amount control device that controls the amount of cement milk injected from the grout pump device 20 to the treatment device 28. The injection amount control device includes a processing machine control system 32 that raises the processing machine 28 after a certain period of time after starting the injection of cement milk, and a processing machine control system 32 that raises the processing machine 28 after starting the injection of cement milk. The grout pump device 20 is controlled by a constant flow rate value for a certain period of time until it starts rising, and the grout pump device 20 controls the grout pump device 20 to
The amount of injection into the grout pump device 20 is maintained constant, and when the treatment device 28 is raised thereafter, the rate of rise of the treatment device 28 is converted into a flow rate, and the flow rate value obtained is used to increase the grout pump device 20.
an injection amount control system 25 that controls the amount of injection from the grout pump device 20 to the treatment machine 28 so as to follow the rising speed of the treatment machine 28; and a scheduled integrated flow rate corresponding to the rising rate of the treatment machine 28. A flow rate value correction system 42 is provided which calculates the difference between the actual injection amount and the actual cumulative injection amount, adds this value to the flow rate value when the processing machine 28 is raised, and corrects the same flow rate value.

(Function) The cement milk injection device for soft ground improvement work of the present invention is configured as described above, and the processing machine control system 32 of the injection amount control device starts the cement milk injection and then processes it after a certain period of time. Machine 28
to rise. In addition, the injection amount control system 25 of the injection amount control device controls the grout pump device 20 at a constant flow rate value for a certain period of time from the start of cement milk injection until the processing machine 28 starts rising. The injection amount from the grout pump device 20 to the treatment machine 28 is held constant, and when the treatment machine 28 is raised thereafter, the grout pump is adjusted according to the flow rate value obtained by converting the rising speed of the treatment machine 28 into a flow rate The device 20 is controlled to adjust the amount of grout pumped from the grout pump device 20 to the treatment device 28 so as to follow the rising speed of the treatment device 28. Further, when the processing machine 28 rises, the flow rate value correction system 42 of the injection amount control device calculates the difference between the planned integrated flow rate and the actual integrated injection amount corresponding to the amount of rise of the processing machine 28,
This value is added to the flow rate value when the processing machine is raised, and the same flow rate value is corrected. With this flow rate value correction system 42,
There is no need to increase the precision of flow rate control from moment to moment, and there is no need to use a servo valve.

(Example) Next, the cement milk injection device for soft ground improvement work of the present invention will be explained using an example shown in Figs. 2 to 11. 1 in Fig. 2 is the power supply for the entire controller, and the AC is converted to 24V DC,
It is adapted to be supplied to a central control unit 2.

In addition, the central control unit 2 receives a 5V DC current from a power supply 3 exclusively for the central control unit 2, and the buzzer output from the central control unit 2 is transmitted via the relay unit 4 to detect an abnormality in the central control unit. The signal is sent to the indicator light 5, and the abnormality indicator light 5 is turned on.

Further, a power failure protection unit 6 is attached to the central controller 2 to protect the memory of the central controller 2 in the event of a power outage.

Further, 7 is an adder connected to each adder (see 24 in FIG. 4) described later, and the output signal (total flow rate voltage signal) from the adder 7 is sent to a pair of V/F converters 8, 8. The signal is converted into a pulse signal having a frequency corresponding to the voltage of the total flow voltage signal, and is sent to relays 9, 9 of V/F converters 8, 8, respectively.

Among the relays 9, 9, one relay 9 is
The other relay 9 is connected to a counter 10, and the counter 10 is connected to a reset switch 11 and a signal generator 12 for resetting the counter to zero. It is designed to count the number of and output a current signal according to the count value.

Reference numeral 20 in FIG. 4 is a grout pump device, and in this embodiment, the grout pump device 20 is composed of a leverable motor for adjusting the tilting angle of the swash plate and a leverable motor for adjusting the tilting angle of the swash plate. a hydraulic pump for adjusting the tilting angle of the swash plate; a hydraulic pump for driving a grout pump driven by the hydraulic pump;
It consists of a grout pump. There are four grout pump devices 20, and each of the grout pump devices 20 includes a potentiometer 21 for detecting the swash plate tilt angle position of the hydraulic pump, and a cement milk flow rate. A cement milk flow rate detector 22 is provided to detect the flow rate of cement milk.

In addition, each of the cement milk flow rate detectors 22 provided in each of the grout pump devices 20 includes:
There are two output ends, and each output end is connected to two converters 23, 23, which convert the detection signal from the cement milk flow rate detector 22 into the standard input signal (DC) of the controller. 1~
5V standard input signal).

Further, the output terminals of the converters 23, 23, which are two in each pump device 20, are connected to each of the four adders 24, and the output terminals of each adder 24 are the input/output terminals of the central control device 2. and the first to fourth for controlling the injection amount of the grout pump.
Local station (injection amount control system) 25-1
~ 25-4, and the detected values from the two rising ends of the cement milk flow rate detector 22 → the two converters 23 are added by the adder 24, and the values are added to the first to fourth local stations 25-1. ~
25-4.

Further, 26 is a decoder connected to each of the potentiometers 21 for detecting the swash plate tilt angle position, 27 is a relay, and each of the decoders 26 is connected to the first to fourth local stations 25-1 to 25-4. , the swash plate tilt angle position detection signal obtained by the potentiometer 21 for detecting the swash plate tilt angle position of the hydraulic pump is transmitted to the first to fourth local stations 25-.
1 to 25-4.

Also, the first to fourth local stations 25-
1 to 25-4 are connected to each grout pump device 20 via a decoder 26, and each of the grout pump devices 20 can be rotated forward or reverse by control signals from the first to fourth local stations 25-1 to 25-4. It is designed to be driven in the direction.

Further, the tip of a wire hanging down from a winch (not shown) via a sheave 29 is attached to a processing machine 28, and a rotary encoder 3 is attached to the shaft of the sheave 29.
0 is installed, and the same rotary encoder 3
0, the vertical speed of the processing machine 28 is detected. Note that the rising speed of the processing device 28 is set manually or automatically. Also, the same processing machine 28
is suspended and supported by a wire extending from a winch, and the lifting speed of the processing machine 28 is determined by the wire hoisting speed of the winch. The operation of the winch is controlled automatically or manually so that the winch meets the specified speed conditions. The prescribed speed conditions may be constant during the entire ascent or may vary depending on depth. Furthermore, when the ship moves up and down based on changes in the tide level, etc., the ground speed may be controlled to a predetermined value. Specifically, as shown in FIG. 6, it is input to the PV circuit of the terminal 32 as a withdrawal (ascent) speed signal manually or by an appropriate mechanism. Also, terminal (processing machine control system) 32
The D1, 1 circuit of the terminal 32 is inputted as a manual extraction signal, and the D1, 2 circuit of the terminal 32 is inputted as an extraction start signal. This withdrawal start signal is
Since it is output through the memory M and the timer delay D, the treatment machine 28 is raised after a certain time lag (after a certain period of time) after the grout pump is started.

Further, as shown in FIG. 4, the output terminal of the rotary encoder 30 is connected to a terminal 32 via an F/I converter 31 and a decoder 26, and the terminal 32 is connected to a terminal 32 which is sent from a tide gauge 33 via the decoder 26. The coming tide level detection signal,
The setting signal sent from the manual setting device 34 that sets the injection amount during automatic mode injection, the drawing start signal sent from the drawing start switch 35, and the manual mode switching sent from the manual mode changeover switch 36. In response to the signal, manual control indicator lamp 3
7 to indicate that the control has shifted to swash plate tilt angle control.

Also, at the fourth local station 25-4,
Switch 38 for notifying the control system of the end of injection
is connected.

Also, the 1st to 4th local stations 25-1
~25-4 is connected to the alarm lamp 39, and when the flow rate decreases abnormally, the alarm lamp 39
is starting to light up.

In addition, as shown in Fig. 5 and Fig. 6,
Each of the local stations 25-1 to 25-4 constitutes one unit of the same controller, and the terminal 32 detects the drawing speed of the processing machine 28 and calculates the amount of cement milk to be injected accordingly. The injection amount signals obtained as a result are
The data is sent to local stations 25-1 to 25-4.

In the cement milk injection apparatus described above in FIGS. 2 to 6, when the first to fourth local stations (injection amount control system) 25-1 to 25-4 are set to cascade mode, the flow diagram in FIG. As shown, the tilting angle of the swash plate of the hydraulic pump is controlled according to the output value of the manual setting device 34. The cement milk injection device waits in this state,
At this time, the hydraulic pump for driving the grout pump is
It has been unloaded and cement milk injection has not started. Note that the unload control system is not shown.

When the withdrawal start switch 35 is closed in this state, the unloading is reset and the grout pump is started at the same time as the terminal 3 shown in FIG.
D1 of 2 (processor control system), pulled out (raised) to 2 circuits
A start signal is sent and memory M is set.
A timer delay D is interposed between this memory M and the AND circuit (AND circuit), and when a predetermined time has elapsed, the AND circuit (AND circuit)
The output of becomes 1, this output is inverted by the NOT circuit, and then the OR circuit (OR circuit)
added to. In addition, the output of this OR circuit (OR circuit) is applied to the switching gate T as a gate switching signal, and the AUXI input to which the manual setting value in the central control room is input.
Either the circuit or the PV circuit into which the drawing speed signal is input is selected by switching. That is, before the start of drawing and for a certain period of time after the start of drawing, the central control room manual setting value input to the AUXI circuit is selected, and after a certain period of time, the drawing speed signal input to the PV circuit is selected. Ru. Further, the output of the OR circuit (OR circuit) is a selection gate of either the PV circuit to which the added flow rate signal is input or the AUXI circuit to which the pump tilting angle signal is input.The first to fourth local stations 25-1 -25-4, the pump tilt angle is selected as the feedback signal source during non-injection and at the beginning of injection, and the flow rate is selected during injection.

Also, the 1st to 4th local stations 25-1
~ When 25-4 is set to manual extraction mode, the manual extraction signal input of D1, 1 circuit of terminal 32 becomes 1, the output of the OR circuit (OR circuit) becomes 1, and the input to the AUXI circuit, that is, Manual settings are selected.

The purpose of providing the above functions is as follows.

(1) Cement milk is not discharged from the tip of the processing machine 28 immediately after the grout pump starts operating. Therefore, while the start of the rise of the treatment machine 28 is slightly delayed from the start of operation of the grout pump,
During this time, a certain amount of cement milk is discharged. The constant flow rate at this time is set using a manual setting device. If the manual setting value set in this manual setting device is set close to a value commensurate with the scheduled processing machine rising speed, switching can be performed smoothly.

(2) Even when not injecting, the hydraulic pump's swash plate tilt angle is set close to the planned flow rate, so the flow rate rises after injection starts compared to when the hydraulic pump's swash plate tilt angle rises from zero. is fast.

(3) At the start of operation, the pipes are not filled with liquid and there are large disturbances such as air bubbles. However, since no feedback signal is obtained from the flow rate at the start of injection, control at the start of operation is stable.

As mentioned above, the terminal 32 shown in FIG.
Manual setting value input to the AUXI circuit is checked by the system check circuit SC to see if it is an abnormal input, and the calculation unit F ₂ (X ₂ ) determines that Y ₂ = A ₂ X ₂ + B ₂ or less, Yn: Injection Flow rate Xn: Actual drawing speed An and Bn: Parameter function calculations are performed to determine the total flow rate for the input value. Also, terminal 32 shown in Figure 6
The drawing speed signal input signal to the PV circuit is sent to the digital filtering circuit DF via the system check circuit SC to cut out disturbance noise.
In addition, the tide level signal input to the AUX2 circuit of the terminal 32 shown in Figure 6 is sent to the digital filtering circuit DF to avoid the influence of waves, etc., and the rate of change in tide level per minute ΔL is calculated by the following formula. Ru.

ΔL=L _o −L _o1 L _o : Current tide level L _o1 : Tide level 1 minute ago This output and the above-mentioned withdrawal speed signal output are added by an adder, and as a result, the apparent withdrawal speed is calculated.
Assuming that X _{1 ′, the actual drawing speed X 1 will be X 1 = 1} ′+ΔL.

In order to convert this actual drawing speed signal into a set injection flow rate, the following linear conversion is performed.

Y ₁ = F ₁ (X ₁ ) = A ₁ X ₁ + B ₁ The converted set injection flow rate signal is sent to the ratio setter
It is sent to RS1 to RS4, and the flow rate to be shared by the first to fourth local stations 25-1 to 25-4 is determined. On the other hand, the pump tilt angle input to the AUX1 circuit of the first to fourth local stations 25-1 to 25-4 is connected to the digital filtering circuit DF.
Y ₃ = _{F 3} (X _{3 )}
= A ₃ X ₃ + B ₃ It is converted into a flow rate signal using the calculation algorithm. In addition, in order to prevent the addition flow rate input to the PV circuits of the first to fourth local stations 25-1 to 25-4 from affecting the pump pulsation, it is sent to the digital filtering circuit DF and added to the flow rate signal. converted. Also terminal 32
The set injection amount signal sent from the first to fourth
Local station 25-1 to 25-4 PV
The flow rate signal sent from the circuit or the AUX1 circuit is compared, and a control output corresponding to the difference is outputted to the grout pump device 20 from the forward rotation output terminal or the reverse rotation output terminal. In this embodiment, an on-off signal subjected to pulse width modulation is output from the output terminal, and the reversible motor for adjusting the tilting angle of the swash plate of the hydraulic pump is driven by the on-off signal.

When the injection end switch 38 is closed, the injection end signal is input to the input terminal of the D1 circuit of the fourth local station 25-4.
The memory M of the terminal 32 is reset, and at the same time, the hydraulic pump for driving the grout pump is unloaded and the grout pump is stopped. Also, the swash plate tilt angle of the hydraulic pump is adjusted during manual setting to prepare for the start of the next injection.
Further, the signals from the two flowmeters 22 shown in FIG. input to the circuit. The difference between these addition inputs is calculated inside the first to fourth local stations 25-1 to 25-4, and two individual flow rates and one added flow rate signal are created. For individual flow rates, each flow rate lower limit is checked.

When the terminal 32 is placed in the manual mode, the terminal 32 is disconnected from the input signal from the central controller 2, and the terminal 32 operates as a manual setting device. Furthermore, if the first to fourth local stations 25-1 to 25-4 are in cascade mode and set to automatic withdrawal, the first to fourth local stations 25-1 to 25-4
25-4 performs control using the swash plate tilting angle of the hydraulic pump as a feedback signal, and thereafter performs control according to the manual control output (MV value) of the terminal 32 using the signal from the flow meter as a feedback signal.

Also, the 1st to 4th local stations 25-1
When 25-4 is set to manual mode, each operates as a manual setting device without automatic control.

A time chart for the automatic pulling operation is shown in FIG. 8, and a time chart for the manual pulling operation is shown in FIG. 9.
Shown in the figure. In the case of automatic pulling operation, as shown in Figure 8, after a certain period of time has elapsed after the command to start pulling out,
The rising speed is configured to be accelerated with a constant time constant, and the rising speed changing time constant matches the injection amount changing time constant of the grout pump.

In the embodiment shown in FIGS. 2 to 6, the tilting angle signal of the hydraulic pump is controlled from the manual setting device by feeding back the tilting angle signal during manual control. , as shown in FIG. 10, an OR circuit 40 is provided in front of the gate circuit 41,
The injection amount may be controlled using the injection amount as a feedback signal.

Next, the most distinctive feature of the present invention will be explained. In the present invention, as shown in FIG. 11, a local station (flow rate value correction system) 42 is further added as shown in FIG. 2. This local station 42 inputs the amount of rise of the processing machine 28, converts it into a planned cumulative flow rate (required injection volume), compares it with the actual cumulative injection volume, and determines a correction amount based on the difference. As shown in Fig. 2, the rising speed of the processing machine 28 is converted into voltage pulses by the V/F converter 43, which enters the counter unit 45 via the relay unit 44, and further outputs to the terminal 32, which outputs the rising speed of the processing machine 28 to a voltage pulse. enters the local station 42 as The actual cumulative injection amount also enters the local station 42. The counter unit 45 is reset by the same switch 11 as the counter 10 for the cumulative injection amount. Also the 11th
PV of local station 42 as shown in the figure
The amount of rise of the processing machine 28 that has entered the circuit receives an input check, and is converted to the processing machine 2 by the conversion formula Y ₆ = A ₆ X ₆ + B ₆ .
It is converted into a planned cumulative flow rate corresponding to the increase amount of 8. Further, the difference Y ₉ = Y ₆ − Y ₇ between this planned cumulative flow rate Y ₆ and the actual cumulative injection amount Y ₇ inputted from the AUX1 circuit of the local station 42 is calculated by the adder 46, and the value is high-low cut. After that, the ratio setting device 47 calculates Y ₁₀ =P×Y ₉ (where P is the magnification (constant) for conversion from Y ₉ to Y ₁₀ ).
A correction amount is determined and sent to the terminal 32. On the other hand, after the withdrawal speed signal input to the PV circuit of terminal 32 is converted into a flow rate value, Y ₁₁ =
An addition operation of Y ₁ + Y ₁₀ is performed to obtain a flow rate set value signal. Note that in the terminal 32, the correction for the tide level is omitted, but this is done to simplify the explanation, and it is also possible to perform the correction for the tide level. In that case, you need to add one with a terminal.

(Effects of the Invention) As described above, the cement milk injection device for soft ground improvement work of the present invention operates the processing device 28 after a certain period of time after starting cement milk injection by the processing device control system 32 of the injection amount control device. raise. In addition, the injection amount control system 25 of the injection amount control device controls the grout pump device 20 at a constant flow rate value for a certain period of time from the start of cement milk injection until the processing machine 28 starts rising. hand,
The injection amount from the grout pump device 20 to the treatment machine 28 is kept constant, and when the treatment machine 28 is raised thereafter, the grout pump device 20 Since the injection amount from the grout pump device 20 to the treatment machine 28 is adjusted to follow the rising speed of the treatment machine 28, no uninjected portion of cement milk is created in the ground.

Further, as described above, the injection amount control system 25 of the injection amount control device controls the grout pump device to maintain a constant flow rate for a certain period of time from the start of cement milk injection until the processing machine 28 starts to rise. 20 to keep the amount of injection from the grout pump device 20 to the treatment machine 28 constant, and when the treatment machine 28 subsequently rises, the flow rate obtained by converting the rising speed of the treatment machine 28 into a flow rate. Since the grout pump device 20 is controlled based on the value and the amount of injection from the grout pump device 20 to the treatment device 28 is adjusted to follow the rising speed of the treatment device 28, hunting phenomena that tend to occur in transient response control can be avoided. can eliminate unstable operation.

Furthermore, when the processing machine 28 rises as described above,
The flow rate value correction system 42 of the injection amount control device calculates the difference between the planned cumulative flow rate and the actual cumulative injection amount corresponding to the amount of rise of the processing machine 28, and adds this value to the flow rate value to obtain the same flow rate value. Since the correction is performed, it is possible to eliminate the cumulative error that occurred between the start of injection and the end of injection, and cement milk can be injected into the ground with high accuracy.

Furthermore, since the cumulative error is corrected by the flow rate value correction system 42, in order to make the inflow rate follow the rising speed of the treated air 28, it is no longer necessary to use high-precision control that requires the use of a servo valve, and an expensive servo valve is not required. In addition to being unnecessary and easy to maintain,
This has the effect of eliminating failures that occur in the servo valve part.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an outline of a conventional cement milk injection device for soft ground improvement work, Fig. 2 is a block diagram showing an embodiment of the cement milk injection device for soft ground improvement work according to the present invention, and Fig. 3 4 is a block diagram of the processor control system and the injection amount control system. FIGS. 5 and 6 are functional block diagrams of the processor control system and the injection amount control system. The figure is a sequence flow diagram, Figure 8 is a time chart of automatic extraction operation, Figure 9 is a time chart of manual extraction operation, and Figure 10 is a function of another embodiment of the above-mentioned processing machine control system and the above-mentioned injection amount control system. FIG. 11 is a functional block diagram of the flow rate value correction system. 1...Controller power supply, 2...Central control unit, 3...
... Dedicated power supply, 4 ... Relay unit, 5 ... Central control unit abnormality indicator light, 6 ... Power failure protection unit,
7... Adder, 8... V/F converter, 9...
Relay, 10... Counter, 11... Reset switch, 12... Signal generator, 20
... Grout pump device, 21 ... Potentiometer for detecting swash plate angle position, 22 ... Flow rate detector, 2
3...Converter, 24...Adder, 25-1~
25-4...Local station (injection amount control system), 26...Converter, 27...Relay, 2
8... Processor, 29... Sheave, 30... Rotary encoder, 31... F/I converter, 32
... Terminal (processing machine control system), 33 ... Tide level gauge, 34 ... Manual setting device, 35 ... Pulling start switch, 36 ... Manual mode changeover switch, 37 ...
...Manual control display lamp, 38...Switch, 39
... Alarm lamp, 40 ... OR circuit, 41 ... Gate circuit, 42 ... Local station (flow rate value correction system), 43 ... Converter, 44 ... Relay unit, 45 ... Counter, 46 ... Adder , 47... Ratio setting device, 48... Injection maximum limit display lamp.

Claims (1)

[Claims] 1. A processing machine 28 that can be raised and lowered to penetrate into the ground and inject cement milk, a grout pump device 20 that injects cement milk into the ground through the processing machine 28 when the processing machine 28 is raised, and the grout pump. It has an injection amount control device that controls the amount of cement milk injected from the device 20 to the processing machine 28, and the injection amount control device is configured to raise the processing machine 28 after a certain period of time after starting the injection of cement milk. and a treatment machine control system 32 that controls the grout pump device 20 with a constant flow rate value for a certain period of time from the start of cement milk injection until the treatment machine 28 starts rising.
The grout pump device 20 is controlled by the flow rate value obtained by converting the rising speed of the treating machine 28 into a flow rate when the treating machine 28 rises after that. An injection amount control system 25 that adjusts the injection amount from the pump device 20 to the processing machine 28 to follow the rising speed of the processing machine 28, and a planned integrated flow rate and an actual integrated injection amount corresponding to the rising amount of the processing machine 28. A cement milk injection device for soft ground improvement work, characterized in that a flow rate value correction system 42 is provided, which calculates the difference between the values and adds this value to the flow rate value when the processing machine 28 is raised, and corrects the same flow rate value.