JP3179041B2 - Ground drilling rig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground excavator having an uninterruptible power supply.

[0002]

2. Description of the Related Art Conventionally, in a ground improvement method such as a deep mixing improvement method or a soil pile construction method, a ground excavator is used for drilling. As shown in FIG. 3, for example, a ground excavator of this type includes a leader 2 supported and erected on a base machine 1, an excavation shaft 4 hung up and down along the leader 2, and The stirring blade 3 provided at the tip of the shaft 4, a driving unit 5 for rotatingly driving the excavating shaft 4 by an electric motor, a control panel 6 for controlling the driving of the driving unit 5, and a control panel 6 An operation panel 7 for issuing an excavation operation command is provided. The control panel 6 is provided with an electromagnetic contactor 9 for various drive controls of the drive unit 5 on a path for supplying power from the generator 8 as a power supply to the drive unit 5, thereby forming a power supply circuit. Further, a part of the power supply is distributed to the control panel 6 on the input side of the electromagnetic contactor 9 of the power supply circuit, and the power is supplied to the electromagnetic contactor 9 via a control unit 10 which controls opening and closing of the electromagnetic contactor 9. The control circuit is configured such that the power is supplied. In this excavation apparatus, the control unit 10 opens and closes the electromagnetic contactor 9 in response to an excavation operation command from the operation unit or by automatic control, thereby controlling the rotation of the electric motor of the driving unit 5 while excavating. Is performed.

In recent years, a deep underground space has been required to be excavated in the development of a deep underground space, and the diameter of the excavation hole has been increased in order to increase construction efficiency. In such excavation, since the excavation load, particularly the load at the start of excavation, becomes excessive, it goes without saying that a driving force for the excavation shaft corresponding to the excavation load is required.

[0004] Generally, either a hydraulic motor or an electric motor is used as a driving means of an excavating shaft in a ground excavating apparatus, but when an excessive load is applied as described above, the above-described conventional example is used. An electric motor is often used as shown in FIG. In addition, since this type of ground excavator is used outdoors, a portable engine generator is generally used as a power source for driving electric power.

[0005]

However, the conventional ground excavator using an electric motor has the following problems.

That is, if an excessive load is applied to the electric motor at the start of excavation, the power supply voltage drops, and the power distributed for opening and closing the electromagnetic contactor decreases. Before starting to rotate, each electromagnetic contactor provided in the power supply circuit is in an open state (off state in which power is not supplied to the motor), and it has often been a problem that excavation cannot be started.

In particular, the tendency is remarkable when the excavation is temporarily stopped during the excavation and then started again, or when a stirring blade having a large stirring radius is attached.

In addition, the above-mentioned voltage drop of the power supply at the start of excavation occurs intermittently, and the movable switch portion of the electromagnetic contactor often repeatedly opens and closes violently, causing damage to the electromagnetic contactor and shortening its life. Had become.

In particular, a conventional ground excavator uses many electromagnetic contactors for various controls, and when it is damaged, it takes a considerable amount of time to replace it, resulting in a decrease in construction efficiency. .

In order to solve the above first and second problems, that is, to start the excavating shaft smoothly, it is conceivable to use a large-capacity power source. Using power supplies was uneconomical and problematic.

Accordingly, a main object of the present invention is to provide a highly economical excavator capable of solving all the above problems and smoothly starting excavation even with a relatively small capacity power supply. is there.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a digging means, an electric motor for driving the digging means, and an electric switch means for controlling the driving of the electric motor. Is supplied to the electric motor via the electric switch means, and a part of the electric power from the power supply is distributed and supplied as power for the switch operation of the electric switch means. A ground excavation device, wherein a part of the electric power from the power source is supplied as a power for a switch operation of the electric switch means to a negative path from the excavation means side.
Excessive load on the electric motor due to load
The electric switch means is activated when
An uninterruptible power supply for supplying power for operation is provided.

As a more specific mode, a leader supported by a base machine and erected, a digging shaft having a stirring blade at a tip end and capable of moving up and down along the leader, and rotating the digging shaft is driven. An electric motor, an electromagnetic contactor for controlling the driving of the electric motor, and a control unit for controlling the opening and closing operation of the electromagnetic contactor, wherein power from a power supply is supplied to the electric motor via the electromagnetic contactor And said
A ground excavation device configured to distribute a part of power from a power supply and supply the power to the control unit as power for an opening / closing operation of the electromagnetic contactor, wherein a part of the power from the power supply a path but supplied to the control unit, the drilling hand
Load on the electric motor due to load from the stage side
Is activated when the state becomes excessive, the electric switch means
There is also proposed a device in which an uninterruptible power supply for supplying power for the switch operation is provided.

In the present invention, since the uninterruptible power supply is provided in the power supply path for the switch operation of the electric switch means, even if the power supply voltage drops at the start of excavation, the switch operation of the electric switch means is performed. There is no reduction in the power distributed to the user. Therefore, in the ground excavator according to the present invention, excavation can be started smoothly even when the load on the electric motor is excessive. This means that the ground excavator of the present invention can perform excavation smoothly even with the use of a power source having a relatively small capacity, and is economical. Further, in the ground excavator according to the present invention, there is no possibility that the electromagnetic contactor is damaged or the life is shortened, thereby lowering the construction efficiency.

The electric switch means according to the present invention includes:
Means for opening and closing a switch by electric power, and more specifically means a magnetic contactor, a relay, and the like.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a ground excavator according to the present invention will be described in more detail with reference to the drawings.

FIG. 1 shows a specific example of a ground excavation apparatus according to the present invention. In comparison with a conventional ground excavation apparatus, a part of power supply power at an input side of an electromagnetic contactor 9 in a control panel 6 is shown. Is distributed to control the opening and closing of the electromagnetic contactor 9
The uninterruptible power supply 20 is provided in a path supplied to the power supply. The excavator of this example is the same as the conventional excavator described above, and the description thereof is omitted here.

The excavator shown in FIG. 1 is a so-called single-axis excavator, but the present invention is not limited to this. As is clear from the illustrated example, the present invention has an advantage that the existing equipment can be used as it is because the uninterruptible power supply is simply provided in the control circuit of the existing excavator. Accordingly, the present invention is widely applicable to multi-axis drilling rigs or other drilling rigs.

In the present invention, various known uninterruptible power supplies can be used as appropriate. Since the uninterruptible power supply is well known to those skilled in the art, it will be briefly described here. An uninterruptible power supply is a device that supplies stabilized power to an important load such as a computer without a power failure. FIG. 2 shows an uninterruptible power supply 20 having a bypass. A rectifier 21 and an inverter 22 are connected in series from the AC input side, and a storage battery 23 is provided in a branch between the rectifier 21 and the inverter 22. Normally, the AC input is normally converted into DC power by the rectifier 21 and supplied to the inverter 22. The inverter 22 converts this DC power back to AC power again and outputs it as AC output. The inverter 22 maintains the AC output frequency with a constant accuracy by a reference oscillator (not shown), compares the AC output voltage with the reference voltage, and maintains the AC output voltage at a constant voltage by feedback control.

The rectifier 21 simultaneously charges a storage battery 23 that stores backup power at the time of a power failure. Therefore, the rectifier 21 has a constant voltage control function for charging the storage battery 23.

When a power failure, instantaneous voltage drop, voltage drop, or the like occurs in the input power, the DC power stored in the storage battery 23 is automatically supplied to the inverter 22 and the inverter 2
No. 2 supplies an AC output of a constant voltage and a constant frequency without any instantaneous interruption to the output side, and does not cause a power failure or the like.

The bypass circuit 24 and the bypass changeover switch 25 are provided to cope with an inspection of the uninterruptible power supply 20 or to cope with an emergency. When the bypass changeover switch 25 is switched, AC power is supplied to the AC output side. Supplied.

In the present invention, such an uninterruptible power supply 2
0 is provided in a power supply path to the control unit 10 that performs the opening / closing operation of the electromagnetic contactor 9. Therefore, the power supplied for the opening / closing operation of the electromagnetic contactor is uninterrupted.

The ground excavator of the present invention is basically the same as a conventional excavator at the time of normal excavation, and the electric power from the generator 8 is supplied to the electric motor of the driving means 5 via the electromagnetic contactor 9. And the excavation shaft 4 is rotated.
At this time, the electric power from the generator 8 is also distributed to the control unit 10, and the electromagnetic contactor 9 is closed by this electric power. The excavating operation of the excavator is performed by controlling the electromagnetic contactor 9 by the control unit 10 in accordance with an operation command from the operation panel 7. Also, similarly to a normal excavator, the excavation operation information such as the temperature of the electric motor of the driving means 5 is transmitted to the control unit 10.
The control unit 10 may automatically stop when an abnormal state such as overheating of the motor occurs.

Unlike the ordinary excavation state, for example, after excavation is performed to a predetermined depth, the excavation is temporarily stopped, grouting agent is injected at the depth, and then the excavation shaft 4 is moved in reverse to the previous excavation. In the case of performing the ground injection method in which the steps of rotating the excavation are performed, when the excavation shaft 4 is started by the reverse rotation after the excavation is stopped, the electric power is supplied to the electric motor of the driving means 5 and the excavation is not immediately started. Then, the load applied to the electric motor becomes excessive. When the load applied to the electric motor becomes excessive, the voltage of the generator 8 drops.

In such a case, in the conventional excavator, before the excavation shaft 4 starts to rotate, the power distributed to the electromagnetic contactor 9 decreases and the electromagnetic contactor 9 is in an open state, that is, the driving means 5 Power is not supplied, and excavation becomes impossible. Further, in the conventional excavator, when the voltage drop of the generator 8 is intermittent, not only the excavation becomes impossible but also the electromagnetic contactor 9 opens and closes violently, so that the electromagnetic contactor may be damaged or shortened in life. Will be invited.

On the other hand, in the excavator of the present invention, in such a case, the uninterruptible power supply 20 immediately supplies power for opening and closing the electromagnetic contactor 9 from a storage battery (not shown) to close the electromagnetic contactor 9. The state is maintained. Therefore, in the ground excavator of the present invention, since the power for opening and closing the electromagnetic contactor is uninterrupted, excavation can be started smoothly even when the excavation load becomes excessive. In other words, it can be said that the excavator of the present invention can perform excavation smoothly even if a generator having a relatively small power generation capacity is used, and is economical. Also, in the present invention, even if the voltage of the generator drops intermittently, the power for opening and closing the electromagnetic contactor is kept constant by the uninterruptible power supply, and the electromagnetic contactor may open and close violently. Because it is not provided, it does not lead to damage or shortened life of the electromagnetic contactor.

The ground excavator of the present invention can be used in addition to the above-described ground injection method, a ground injection method in which excavation is performed stepwise, such as a normal descending step injection and a descending step injection.
The present invention is also suitably used for deep excavation or the like in which excavation is temporarily stopped after excavation to a predetermined depth, and a step of adding an excavation axis and performing excavation is repeated. The ground excavator of the present invention is also suitable for a case where a stirring blade having a large stirring radius is used in order to improve construction efficiency.

As described above, the ground excavator of the present invention is particularly suitable for a construction method in which the load during excavation becomes excessive.
It goes without saying that it may be used for ordinary excavation. In this case, the reliability of the excavator is improved, and extremely stable excavation can be performed.

An experimental example will be shown below to clarify the effect of the present invention.

[Experimental Example] An uninterruptible power supply unit according to the present invention was constructed using a ground excavator equipped with two 90 kW electric motors and having a stirring blade having a predetermined stirring radius at the tip of a drilling shaft (single shaft). The ground excavation was actually performed between the case where the power supply was provided and the case where the uninterruptible power supply was not provided as in the related art, and a comparative experiment was performed to compare the power generation capacity of the generator required for starting the excavation.

<Experiment 1> A viscous ground was excavated to a depth of 25 m using a stirring blade having a stirring radius of 1.0 m and a generator having a power generation capacity different from 350 to 800 kVA. An experiment was conducted in which the rotation of the shaft was temporarily stopped and restarted.

As a result, in the ground excavator of the present invention,
Excavation could be started smoothly with a generator of 00 kVA or more. On the other hand, in a conventional excavator without an uninterruptible power supply, a generator smaller than 600 kVA could not start excavation due to malfunction of the electromagnetic contactor of the control circuit.

<Experiment 2> An excavation experiment was performed in the same manner as in Experiment 1, except that the stirring blade was replaced with one having a stirring radius of 1.5 m.

As a result, in the ground excavator of the present invention, 6
Excavation could be started with a generator of 00 kVA or more. On the other hand, in the conventional excavator without the uninterruptible power supply, it was not possible to start unless the generator was 800 kVA or more.

As apparent from these experiments, the ground excavator of the present invention can start excavation smoothly even with a small-capacity generator as compared with the conventional ground excavator. It turns out to be economical.

[0037]

As described above, according to the present invention, firstly, excavation can be started smoothly even when an excessive load is applied to the electric motor, and secondly, the electromagnetic contactor can be damaged or shortened in life. Third, the excavation work can be performed smoothly even with a generator having a relatively small capacity without causing a decrease in the construction efficiency, and the fourth embodiment is economical.
Since the uninterruptible power supply is simply provided in the control circuit of the existing excavator, there are various advantages such as being economical in that the existing apparatus can be used as it is.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a ground excavator according to the present invention.

FIG. 2 is an explanatory diagram of an uninterruptible power supply.

FIG. 3 is a schematic diagram showing a conventional ground excavator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base machine, 2 ... Leader, 3 ... Stirring blade, 4 ... Excavation axis, 5 ... Driving means, 6 ... Control panel, 7 ... Operation panel, 8 ... Generator, 9 ... Electromagnetic contactor, 10 ... Control part, 20 ... uninterruptible power supply.

Claims (2)

(57) [Claims] An electric motor for driving the excavating means; and an electric switch means for controlling the driving of the electric motor, wherein electric power from a power source is supplied to the electric motor via the electric switch means. A ground excavator configured to be supplied to a motor and to be partially supplied with power from the power supply and supplied as power for a switch operation of the electric switch means, The path in which part of the electric power is supplied as electric power for the switch operation of the electric switch means ,
The electric motor has a problem due to the load from the digging means.
The switch is activated when the load
Ground excavating equipment, comprising an uninterruptible power supply for supplying electric power for switch operation of the switch means . 2. A reader supported by a base machine and standing upright, a drilling shaft having a stirring blade at a tip end thereof and capable of moving up and down along the reader, an electric motor for rotating the drilling shaft, and an electric motor. An electromagnetic contactor for controlling the driving of the electric motor, and a control unit for controlling the opening and closing operation of the electromagnetic contactor, wherein power from a power supply is supplied to the electric motor via the electromagnetic contactor, A ground excavator configured to distribute a part of power from a power supply and supply the power to the control unit as power for an opening / closing operation of the electromagnetic contactor, wherein a part of the power from the power supply In the path supplied to the control unit due to a load from the digging means side.
Activated when the load on the
Supply power for switch operation of electric switch means
Ground excavation apparatus characterized by an uninterruptible power supply is disposed that.