JPH0914147A - Water injection device for force feed system for sediment - Google Patents

Abstract

PURPOSE: To automatically maintain a flow rate of water injected in a force feed pipe through which soil is forcibly fed. CONSTITUTION: A water pump 20 is driven by an inverter 22 and a delivery rate of a water pump 20 is changed in proportion to the output frequency of an inverter 22. By inputting a control signal, proportioning to the drive oil pressure of a forced feed device 4, to an inverter 22 from a controller 23, the output frequency of the inverter 22 is varied in proportion to the forced feed load of the forced feed device 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water injection device in a pressure feeding system for feeding excavated soil from a shield machine.

[0002]

2. Description of the Related Art FIG. 3 shows an outline of excavation work by a conventional shield machine. The earth and sand excavated by the shield machine 1 is discharged to the pressure feeding device 4 through the discharge port 3 of the screw conveyor 2. The pressure-feeding device 4 sucks the earth and sand and pressure-feeds it through the pressure-feeding pipe 5 toward the outside.

6 is a water injection pipe installed in the middle of the pressure supply pipe 5, 7 is a water injection pipe for supplying high pressure water to the water injection pipe 6, 8 is a water pump for generating high pressure water, and 9 is a pressure supply device 4. The hydraulic unit, 10 is a driver truck of the shield machine 1.

The high-pressure water discharged from the water pump 8 passes through the water injection pipe 7 and the water injection pipe 6 and the inner surface of the pressure feed pipe 5 and the earth and sand, that is,
Water is injected between the pumped product and the pumped product to reduce the pumping resistance.

[0005]

In the above-mentioned conventional apparatus, whether or not to inject water depends on the operator's judgment. When injecting water, the operator instructs the driving hydraulic pressure of the pressure feeding device 4 by the pressure gauge. It was necessary to adjust the water injection amount by judging the pressure feeding load of the pressure feeding device 4 by looking at the value.

For this reason, the operator is required to constantly monitor the operating state of the pressure feeding device 4 during operation, but in normal shield work, the operator also operates the shield machine 1 and the pressure feeding device 4, so that it is sufficient. It is difficult to monitor the operating state of the pumping device 4, and therefore, it causes pumping failure or excessive water injection due to insufficient water injection, and in the case of excessive water injection,
The fluidity of the sediment becomes high, and extra work is required to treat this sediment.

[0007]

SUMMARY OF THE INVENTION The present invention has been invented to solve the above-mentioned problems, and its gist is to provide a pressure-feeding device driven by hydraulic pressure and a force applied by the pressure-feeding device. In a water injection device in a pressure-feeding system for earth and sand, which is equipped with a pressure-feeding pipe for pressure-feeding earth and sand etc. and a water injection device for injecting water into this pressure-feeding pipe, drive the water pump with an inverter A controller is provided which proportionally changes the discharge water amount of the water pump and changes the output frequency in proportion to the pumping load of the pumping device by giving a control signal proportional to the drive oil pressure of the pumping device to the inverter. It is a water injection device in a pumping system for soil and sand.

[0008]

In the present invention, when the drive oil pressure of the pumping device exceeds the set value, a control signal proportional to the drive oil pressure of the pumping device is applied to the inverter, and the inverter controls the rotational speed of the water pump, resulting in pumping. An amount of water proportional to the pumping load of the device is automatically injected into the pumping pipe.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS. In FIG. 1, reference numeral 20 is a water pump, which discharges water in proportion to the number of revolutions thereof. Reference numeral 21 is an electric motor for driving the water pump 20, 22 is an inverter for arbitrarily changing the rotation speed of the electric motor 21, and 23 is a controller, which inputs a signal from a pressure converter installed in a drive hydraulic circuit of the pressure feeding device 4. Then, the drive oil pressure of the pressure feeding device 4 is detected, and a control signal proportional to the drive oil pressure of the pressure feeding device 4 is given to the inverter 22. Incidentally, 24 is a check valve.

FIG. 2 (A) shows the relationship between the drive oil pressure Ph of the pumping device 4 and the control signal Vc of the controller 23, and FIG. 2 (B) shows the control signal Vc given to the inverter 22 and the discharge of the water pump 20. The relationship with the water amount Qw is shown.

However, when the drive oil pressure Ph of the pumping device 4 rises above the set value Pho, the controller 23 causes the control signal V
Output c to the inverter 22. The inverter 22 supplies electric power having a frequency proportional to the given control signal Vc to the electric motor 21.

Thus, when the drive oil pressure Ph of the pumping device 4 exceeds the set value Pho, the water pump 20 starts to operate and the rotation speed of the water pump 20 is controlled in proportion to the drive oil pressure Ph of the pumping device 4. The water pump 20 discharges an amount of water proportional to the pressure-feeding load of the pressure-feeding device 4. The high-pressure water discharged from the water pump 20 is injected into the pressure feed pipe 5 through the water injection pipe 7 and the water injection pipe 6. The high-pressure water supplied into the water injection pipe 6 invades between the inner surface of the pressure-feeding pipe 5 and the pressure-feeding substance, and the pressure-feeding substance and the pressure-feeding pipe 5
It reduces the frictional force with the inner surface and greatly reduces the pumping resistance.

[0013]

According to the present invention, the amount of water injected into the pressure-feeding pipe is automatically controlled according to the change in the pressure-feeding load of the pressure-feeding device. Become.

Further, since the optimum amount of water is automatically injected, it is difficult to pump the earth and sand due to the insufficient amount of water injection and the discharge of earth and sand with a large water content due to the excessive amount of water injection is prevented, and troubles can be prevented and unnecessary. Aftertreatment is unnecessary.

Furthermore, since the optimum amount of water is automatically injected,
The operator does not need to constantly monitor the operating state of the pressure feeding device, and therefore the burden on the operator can be greatly reduced.

[Brief description of the drawings]

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

FIG. 2 (A) is a diagram showing the relationship between the drive hydraulic pressure of the pressure feeding device and the control signal of the controller in the above embodiment, and (B) is a diagram showing the relationship between the control signal and the discharge water amount of the water pump. is there.

FIG. 3 is a side view showing an outline of tunnel excavation work by a conventional shield machine.

[Explanation of symbols]

 4 Pumping device 5 Pumping pipe 6 Water injection pipe 7 Water injection pipe 20 Water pump 21 Electric motor 22 Inverter 23 Controller

Claims (1)

[Claims] 1. Sediment or the like provided with a pressure-feeding device driven by hydraulic pressure, a pressure-feeding pipe for pressure-feeding earth and sand urged by the pressure-feeding device, and a water-pouring device for pouring water into the pressure-feeding pipe. In the water injection device of the pressure feeding system, the water pump is driven by the inverter, the discharge water amount of the water pump is changed in proportion to the output frequency of the inverter, and the control signal proportional to the driving oil pressure of the pressure feeding device is given to the inverter. A water injection device in a pressure-feeding system for soil and the like, characterized in that a controller for changing its output frequency in proportion to the pressure-feeding load of the pressure-feeding device is provided.