JPH1088568A - Automatic control device for ground improving machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automate the control for the stirring speed and the chemical feeding quantity of a ground improving machine. SOLUTION: A ground improving machine for improving the ground comprises an excavation depth detecting device 11 for detecting the excavation depth from the moving distance of a driving part 4 and an arithmetic device 12. The arithmetic device 12 includes a function of calculating the excavation speed on the basis of the excavation depth input from the excavation depth detecting device 1, a function of calculating the required rotating speed required at present from the calculated excavation speed and a designated rotating speed required for stirring a predetermined constant depth, a function of giving a command for rotating at a required rotating speed to a motor of the driving part 4, a function of calculating the required discharge quantity required at present from the excavating speed and a designated discharge quantity of chemicals require for stirring the predetermined constant depth, and a function of giving a command for discharging a required discharge quantity of chemicals to a chemical feeding pump.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic control device for a ground improvement machine.

[0002]

2. Description of the Related Art Conventionally, there is a ground improvement machine for improving the ground such as hardening the ground. This ground improvement machine
As shown in FIG. 1 as an example to which the present invention is applied, a driving unit 4 is suspended by a wire 5 along a guide rail 3 on a side surface of a leader mast 2 erected and supported by a working machine 1. 5 is lifted and lowered by a winch mounted on the work machine 1 so that the drive unit 4 is moved up and down. The electric motor 6 in the drive unit 4 (FIG. 2)
2), the stirring rod 7 is connected to an output shaft which rotates through a speed reducer by the drive shown in FIG.

The stirring rod 7 has stirring blades 8 and drives the motor 6 of the driving unit 4 to lower the driving unit 4 while rotating the stirring rod 7 at a predetermined number of revolutions. While excavating the ground with the excavating head 9, the ground is stirred with the earth and sand by the stirring blades 8 while the ground improvement chemical liquid such as cement milk supplied through the stirring rod 7 is injected, so that the ground becomes good. ing.

[0004] In the above-mentioned ground improvement, rotation is performed at the number of rotations required to stir a unit depth (in the case of a stirring rod with blades, the number of blade cutting) in order to obtain a good ground, It is necessary to appropriately select the discharge amount of the ink.

[0005]

Conventionally, however, the stirring rod 7 is lowered and raised at a constant speed while being driven to rotate at a predetermined constant rotation speed, and a chemical solution is discharged. There is a problem in that it relies on the intuition of the operator and therefore lacks reliability.

[0006]

SUMMARY OF THE INVENTION The present invention makes it possible to constantly monitor the number of revolutions of a stirring rod, excavating speed, pulling speed, and injection of a chemical solution in accordance with the properties of the ground to improve the ground to the best condition. An object of the present invention is to provide a ground improvement machine, in which a stirring rod having stirring blades is connected to a driving unit mounted on a leader mast so as to be movable up and down, and the stirring rod is rotated and driven by a motor in the driving unit. While excavating, a ground improvement chemical such as cement milk is injected and agitated with earth and sand, and in a ground improvement machine for improving the ground, an excavation depth detection device for detecting an excavation depth from a moving distance of the driving unit. An arithmetic unit, the arithmetic unit having a function of calculating an excavation speed based on the excavation depth input from the excavation depth detection device, a calculated excavation speed and a predetermined constant depth. A function of calculating a required number of revolutions currently required by a predetermined number of revolutions required for stirring, a function of giving a command to rotate the motor of the driving unit at the required number of revolutions, and a function of setting the excavation speed and a preset value It has a function to calculate the required discharge amount currently required from the predetermined discharge amount of the chemical solution required to stir at a certain depth, and a function to give a command to the chemical injection pump to discharge the chemical solution at the required discharge amount. That is.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. Referring to FIG.
As a digging depth detecting device for detecting a stirring depth by the stirring rod 7 from a moving (elevating) distance of the worm, a rotary encoder provided on a shaft portion of a sheave 10 around which a wire 5 suspending the driving unit 4 is wound. A depth detector 11 is provided to detect the excavation depth based on the unwinding amount of the wire 5, and the detection result is input to the arithmetic unit 12.

The swivel unit on the drive unit 4 is provided with a rotation speed detector 13 composed of a rotary encoder for detecting the rotation speed of the stirring rod 7, and the rotation speed detector 13 detects the current rotation speed of the stirring rod 7. The detection result is input to the arithmetic unit 12, and the rotation speed of the electric motor 6 for driving the stirring rod is controlled through the rotation speed inverter 14.

On the other hand, in a chemical supply system from a ground improvement chemical supply source 15 such as cement milk supplied through the swivel section, a discharge amount detector 16 for detecting a discharge amount of a pump is provided. The detection result of the detector 16 is input to the arithmetic unit 12, and the rotation speed of the electric motor 18 for driving the pump is controlled through the pump inverter 17.
Each of these controls is performed by the construction management device 19 based on the calculation results of the calculation device 12.

The rotation speed of the stirring rod 7 is controlled as follows. That is, the minimum number of revolutions (hereinafter referred to as the number of times of blade cutting) required when the stirring rod 7 descends or ascends the unit depth in order to perform good ground improvement is given by the following equation. T = Td + Tu (1) Td = M × ^Nd / Vd Tu = M × ^Nu / Vu Here, T: the number of times of blade cutting (times / m) M: the required number of revolutions at the present time to be adjusted (times / min) V: the speed of the stirring rod d: excavation (down), u: pull-out (up) ).

[0011] Therefore, the blade speed required by stirring by setting the rotation speed at the time of excavation and the excavation speed (down speed) to Nd and Vd, respectively, and the rotation speed at the time of extraction and the extraction speed (up speed) to Nu and Vu, respectively. The number of times T can be realized.

On the other hand, the relationship between the rotation speed N of the stirring rod and the frequency of the rotation speed inverter 14 is as follows: N = R · 120f / P (4) where R: reduction ratio, P: number of motor poles, f: Indicates frequency.

With respect to the chemical liquid discharge amount, it is assumed that the chemical liquid is injected only at the time of excavation, and the minimum discharge amount A (l / m) required when the stirring rod 7 descends by a unit depth is the current required discharge to be adjusted. The amount is Q (l / m) and the excavation speed is V
(M / min), A = Q / V, that is, Q = A · V (5)

Therefore, the required chemical liquid discharge amount A can be realized by performing stirring with the chemical liquid discharge amount and the excavation speed at the time of excavation as Q and V, respectively.

The relationship between the rotation speed of the stirring rod 7 and the frequency of the pump inverter 17 is as follows: N = R · 120f / P (6)

Next, the operation will be described based on a specific example.

Assuming that the predetermined number of rotations per stirring blade of the stirring rod 7 is 350 times / m and the number of the stirring blades 8 provided on the stirring rod 7 is 10, the excavation speed is 1 m.
If the stirring is performed at 35 times / min at a predetermined rotation speed of 3
50 times / m will be realized.

On the other hand, assuming that the discharge amount of the chemical solution is 500 l / m, the discharge may be performed at 500 l / min at an excavation speed of 1 m / min.

Under the above conditions, the electric motor 6 is started to rotate the stirring rod 7, and a chemical solution is discharged from the tip of the stirring rod 7, and the wire 5 suspending the drive unit 4 is lowered to perform the stirring operation. To start.

The digging depth is constantly detected by the digging depth detecting device 11, and the result of the detection is input to the arithmetic device 12, and the digging speed is calculated.

The required number of revolutions is calculated at all times or per unit time based on the above formula, and this value is converted into a frequency based on the formula (6) to convert the value into a frequency.
To the frequency conversion command. As a result, if a change occurs in the excavation speed due to the properties of the excavation ground, etc., the stirring rod 7 is rotated at the required rotation speed that matches the excavation speed at that time,
The rotation speed always corresponds and the excavation speed and the rotation speed maintain a linear relationship as shown in FIG.

The required discharge amount is also calculated at all times or per unit time based on the above formula (6). Based on this value, a frequency conversion command is given to the pump inverter 17 to change the discharge amount of the chemical solution. Thereby, the excavating speed of the stirring rod 7 and the discharge amount of the chemical liquid maintain a linear relationship as shown in FIG.

As a result, even if the excavation speed changes due to the columnar shape of the ground or the like, the stirring rod 7 is adjusted to the required rotation speed and required discharge amount corresponding to the current excavation speed at each time, and the predetermined rotation speed is adjusted. Also, the discharge amount of the chemical solution is maintained.

The above control is arranged as shown in the flowchart of FIG.

That is, automatic adjustment is started (step S ₁ ).
In doing so, the upper limit and lower limit of the rotation speed of the stirring rod 7 with respect to the elevating speed of the stirring rod 7 and the upper limit and lower limit of the pump discharge amount are set (step S ₂ ).

Next, it is determined whether the control is started or whether the control is being continued through the following loop (step S ₃ ). If the control is continued, the elevating speed is calculated from the depth value detected by the movement of the wire 5 (step S ₃ ). step S _4). End If control continuation is (Step S _5).

It is determined whether the elevating speed calculated in step S ₄ is within the adjustment range of the rotation speed of the stirring rod 7 and the discharge amount of the pump (step S ₆ ). lifting speed adjustment (step S ₇₎ is made, the flow returns to step S _4. If the rotation speed is within the adjustment range, an appropriate rotation speed for the current speed is calculated from the lifting speed of the stirring rod 7 (step S ₈ ).

Next, the current rotation speed of the stirring rod 7 is detected by the rotation speed detector 13 (step S ₉ ), and this rotation speed is compared with the actual rotation speed (step S ₁₀ ). If this is not the proper rotation speed, adjust the rotation speed (step S
_11), returns to the step S _9. When the rotation speed is appropriate, automatic adjustment of the pump discharge amount is started.

Here, the pump discharge amount appropriate for the current speed is calculated and determined from the lifting speed of the stirring rod 7 (step S ₁₂ ), and the current pump discharge amount is detected by the discharge amount detector 16 (step S ₁₃ ). . Then compares the actual discharge amount and proper discharge amount (step S _14), by adjusting the amount of discharge when not appropriate discharge amount (step S _15), step S ₁₃
Return to Returns to step S ₁₃ if the proper discharge amount, repeating the loop until the end command is issued.

It is preferable that the motor and the pump used in the present invention have a built-in inverter (frequency conversion device). However, the present invention is not limited to this, and a variable motor (for example, a hydraulic motor) may be used. In the present embodiment, the case where the injection of the chemical solution is performed only during excavation is shown, but it is needless to say that the injection may be performed when the stirring rod is pulled out.

[0031]

As described above, according to the present invention, the required number of revolutions and the required discharge amount of the chemical liquid with respect to the current excavation speed are always calculated, and the rotation of the stirring rod and the chemical liquid are calculated based on the resulting number of rotations and discharge amount. Therefore, even if the excavation speed fluctuates due to the properties of the ground or the like, a predetermined number of revolutions and a predetermined discharge amount can be obtained, whereby efficient and good ground improvement can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a control block diagram.

FIG. 3 is a graph showing a state of automatic adjustment of the rotation speed of a stirring rod.

FIG. 4 is a graph showing a state of automatic adjustment of a pump discharge amount.

FIG. 5 is a flowchart showing control contents.

[Explanation of symbols]

 2 Leader mast 4 Drive unit 5 Wire 6 Electric motor for driving a stirring rod 7 Stirring rod 8 Stirring blade 9 Drilling head 11 Depth detector 12 Computing device 13 Rotation speed detector 14 Rotation speed inverter 16 Chemical liquid discharge amount detector 17 Pump inverter 18 Electric motor for driving pump 19 Construction management device

Claims (1)

[Claims] 1. A stirrer rod having stirring blades is connected to a drive unit mounted on a leader mast so as to be able to move up and down, and this stirrer rod is driven to rotate by a motor in the drive unit to excavate the ground and to remove cement milk or the like. A ground improvement machine for improving the ground by injecting a ground improvement chemical and mixing the soil with the earth and sand, comprising: an excavation depth detection device for detecting an excavation depth from a moving distance of the driving unit; and a calculation device. Is required by the function of calculating the excavation speed based on the excavation depth input from the excavation depth detection device and the calculated excavation speed and a predetermined rotation speed required to stir a predetermined constant depth. A function of calculating a required rotation speed, a function of giving a command to rotate the motor of the drive unit at the required rotation speed, and a function of stirring the digging speed and a predetermined constant depth. A ground having a function of calculating a required discharge amount required at present from a predetermined discharge amount of a required chemical liquid and a function of giving a command to a chemical liquid injection pump to discharge the chemical liquid at a required discharge amount. Automatic control device for improved machine.