JP2001012178A - Electric earth auger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric earth auger capable of eliminating a power generation device mounted in a rear part of a base machine and driving a power generator by an engine of the base machine. SOLUTION: In an electric earth auger in which a leader erected in front of a base machine is provided with an electric motor 20 driving an auger screw, a power generator 12 driven by an engine 11 of the base machine is provided, the power generator 12 is connected with the electric motor 20 through a converter 16 and an inverter 17, and a storage battery 18 charged by the power generator 12 is provided through the converter 16 to supply power of the storage battery 18 to the electric motor 20 in the case of shortage of power of the power generator 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric earth auger in which an auger screw or the like is rotationally driven by an electric motor.

[0002]

2. Description of the Related Art As shown in FIG. 4, an auger driving device 5 equipped with an electric motor is engaged with a guide rail 3 of a reader 2 erected in front of a base machine 1 having an upper revolving structure so as to be able to move up and down. There is known an electric earth auger which is suspended and pushed into the ground while rotating an auger screw 6 provided with a drilling tool at the lower end of an auger driving device 5 to form a hole having a diameter of the auger screw 6 in the ground. .

[0003] The electric motor of the auger driving device 5 obtains electric power from a power generating device 8 mounted behind the base machine 1. In general, a portable engine generator is used as the power generating device 8. In the excavation work using the earth auger, not only the load at the time of excavation greatly varies depending on the soil quality but also the load fluctuation is large. Is installed. Further, the auger driving device 5 includes a type in which the rotation of the electric motor is constant and a type in which an inverter circuit is added so that the output speed can be controlled steplessly.

On the other hand, the engine of the base machine 1 runs, drives an upper revolving structure, drives a winch or the like for raising and lowering the auger driving device 5, and operates an outrigger, a backstay for supporting a reader, and the like. These operations are performed by hydraulic actuators, and a plurality of hydraulic pumps driven by an engine are provided.

[0005]

As described above, the conventional electric earth auger has a power generating engine for supplying electric power to the electric motor of the auger driving device 5 separately from the engine provided in the base machine. In addition to the high cost, there is a problem of fuel supply and maintenance of the engine. Since the power generator 8 is structurally inevitably mounted behind the base machine, the turning radius of the upper turning body of the base machine is reduced. In many cases, it becomes large and difficult to construct on a narrow work site.

Accordingly, an object of the present invention is to provide an electric earth auger in which a generator is driven by an engine of the base machine without the power generator 8 mounted behind the base machine.

[0007]

In order to achieve the above object, the present invention employs the following means. That is, according to the first aspect of the present invention, in a motor-operated earth auger provided with a motor for driving an auger screw or the like on a reader erected in front of the base machine, a generator driven by an engine of the base machine is provided. Is connected to the motor via a converter and an inverter, and a storage battery charged by the generator is provided via the converter, so that the power of the storage battery is supplied to the motor when the power of the generator is insufficient. It is characterized by.

[0008] The electric earth auger is a motor that drives an auger screw with an electric motor. The earth auger machine uses an auger screw and attaches a stirring attachment, and is used for construction other than drilling such as ground improvement. However, the same motor is used, and the present invention is naturally applicable and includes the same.

[0009] In the conventional electric earth auger, a portable engine generator driven by an engine is mounted on a pedestal provided behind the base machine. However, in the present invention, this is abolished and the engine of the base machine is used. The generator is driven, and this generator is not of the large capacity as in the past, but is of the same capacity as the motor.When large power is required due to overload etc., it is replenished from the storage battery. It is something to do.

Normally, in the electric earth auger, when the auger screw is driven, the hydraulic motor of the elevating winch of the auger driving device 5 is not operated, and the engine of the base machine such as a running machine is operated. When in use, the motor of the auger drive is stopped or lightly loaded, so that both engines do not require high loads at the same time. Therefore, the engine of the base machine may be slightly larger than before.

The earth auger has a large load variation due to soil properties and the like, and a load may be suddenly applied. In such a case, it is necessary to prevent the engine from stopping. Therefore, it is convenient to provide an engine load detecting means and to reduce the output of the generator so that the load of the engine does not exceed a predetermined value.

On the other hand, even when the auger screw is not driven, there are many cases where the output of the engine is insufficient, such as when the auger screw is pulled out or running on a slope.
In such a case, an AC machine driven by the engine of the base machine is provided, and the AC machine is connected to the motor via a converter and an inverter, and is charged by the AC machine. A storage battery is provided via the converter, and a conversion means is provided for connecting the AC machine to an inverter when the engine is overloaded by a hydraulic pump driven by the engine while providing a load detection means for the engine, It is preferable to supplement the drive of the hydraulic pump as an electric motor that drives the AC machine with the power of a storage battery.

When excavating an earth auger,
Since the excavation reaction force is received by the base machine, a considerable weight of the counterweight is placed on the rear part of the base machine, but as described in claim 4, the storage battery is mounted on the rear part of the base machine and the mass thereof is counted. If used as a weight, there is no need for a conventional counterweight.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. First, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram showing a power system of an electric earth auger, and FIG. 2 is a plan view showing the arrangement of its components. In this electric earth auger, a gear device 13 is provided on an output shaft of an engine 11 of the base machine 1,
In addition, a generator 12 and a plurality of hydraulic pumps 14 and 15 are provided. They are located behind the engine, almost at the rear of the base machine.

The hydraulic pumps 14 and 15 are the same as those conventionally used, and include hydraulic motors for traveling left and right, hydraulic motors for the winches 32, 33 and 34, hydraulic motors for rotating the upper revolving unit, and Pressure oil is supplied via a switching valve to a cylinder for leader support, outrigger, leader position adjustment, and the like. The configuration of the hydraulic circuit from the hydraulic pump to an actuator such as a hydraulic motor or a cylinder is the same as that of the conventional hydraulic circuit, and thus the description is omitted. The engine 11
A power generator having a larger output than that of a conventional power generator mounted on the rear part of a base machine (for example, 170 KW compared to 130 KW in the past) is used.

The output of the generator 12 is supplied to the motor 2 of the auger driving device 5 via the converter 16 and the inverter 17.
0. The converter 16 and the inverter 17 are connected to a storage battery 18. Converter 1
6 and the inverter 17 are installed at the rear of the cab 31 on the opposite side of the engine 11 of the base machine 1, and the storage battery 18
Is mounted at the rear end of the base machine 1 and also has a function as a counterweight.

Further, a load detecting means 21 for the engine 11 is provided, which measures the oil pressure and the electric load by a sensor (not shown) so as to reduce the output of the generator 12 so as not to exceed the maximum output value of the engine 11. I have to. Next, the operation of the electric earth auger thus configured will be described.

The engine 11 is operated at the rated speed and drives the hydraulic pumps 14 and 15 and the generator 12 connected to the gear unit 13. Operations of the base machine such as running, turning, and operation of various cylinders are performed by sending pressure oil from the hydraulic pumps 14 and 15 to each actuator. At this time, the auger driving device 5 is stopped. The AC power generated by the generator 12 is temporarily converted to DC by the converter 16 and stored in the storage battery 18.

The engine output is controlled so as to give priority to the load from the hydraulic pumps 14 and 15. That is,
The output of the generator 12 is reduced so that the engine load detecting means 21 does not exceed the maximum output value of the engine 11. The AC power generated by the generator 12 is converted to DC by the converter 16, and the AC power generated by the generator 12 is converted into AC of a desired frequency and voltage by the inverter 17 and supplied to the motor 20. When the excavation load is large, electric power is supplied from the storage battery 18 via the inverter 17.
To change the rotation speed, the inverter 17 is operated.
The electric motor 20 of the auger driving device 5 is, for example, 110K
In the case where a power generation device having a capacity of W is used, a power generation device
Equipped with a KW engine and a 350KVA generator, the base machine 1 is equipped with a 132KW engine,
In the electric earth auger of the present invention, a 170 KW engine 11 is mounted on the base machine 1, a generator 12 has 150 KVA, and a storage battery 18 has 200 KVA.

Although the capacity of the generator is less than half of the conventional one, power is supplied from the storage battery 18 for a temporary overload, and a maximum of 350 KVA of power can be supplied to the motor 20. Therefore, in actual work, almost the same ability as the conventional one can be exhibited. Next, an embodiment of the present invention will be described with reference to FIG.

The same components as those in FIG. 1 described above are used for the configuration of the electric earth auger, and the same components are denoted by the same reference numerals and description thereof is omitted. That is, an AC machine 25 and a plurality of hydraulic pumps 14 and 15 are provided in a gear device 13 attached to the engine 11 mounted on the base machine 1.

The arrangement is the same as that of FIG. 2, except that an alternator 25 is provided instead of the generator 12. The hydraulic circuit configurations of the hydraulic pumps 14 and 15 and the actuators thereof are the same as those of the related art. The AC machine 25 normally functions as a generator, and the motor 2 of the auger driving device 5 is connected via the converter 16 and the inverter 17.
Supply power to 0. The converter 16 and the inverter 17 are connected to the storage battery 18 as in the above embodiment.

An engine load detecting means 21 and a switching device 26 for converting the AC machine 25 from a function as a generator to a function as an electric motor in accordance with a signal from the load detecting means 21 are provided. Next, the operation of the electric earth auger thus configured will be described.

The engine 11 is operated at the rated speed, and the hydraulic pumps 14, 1,
5 and the AC machine 25 are driven. The operation of the base machine, such as running, turning and operating various cylinders, is performed by the hydraulic pump 14,
This is done by sending the pressure oil from 15 to each actuator, at which time the auger drive 5 is normally stopped. The AC machine 25 functions as a generator, and the generated AC power is temporarily converted to DC by the converter 16 and stored in the storage battery 18.

The AC power generated by the AC machine 25 is converted to DC by the converter 16, and the AC power is converted to AC of a desired frequency and voltage by the inverter 17 and supplied to the electric motor 20 of the auger driving device 5. When the excavation load is large, electric power is supplied from the storage battery 18 via the inverter 17.

When the motor 20 of the auger drive device 5 is stopped, for example, during traveling, that is, when the connection between the inverter 17 and the motor 20 is cut off, the load detecting means 21
Detects the maximum output value of the engine 11, the switching device 2
6, the connection between the AC machine 25 and the converter 16 is cut off, and the inverter 17 and the AC machine 25 are connected.

When the switching device 26 is switched, power is supplied from the storage battery 18 to the AC machine 25 via the inverter 17, the AC machine 25 functions as an electric motor, and the hydraulic motors 14 and 15 are Drive. Therefore, when the auger screw is pulled out of the rock when it is bitten by a rock, a large power is required and the engine 11
When the output is insufficient, the alternator 25 can be made to function as an electric motor and replenish the engine 11 output.

[0029]

As described above, according to the present invention, the power generator conventionally mounted on the rear of the base machine is abolished, the generator is driven by the engine of the base machine, and large electric power is generated due to overload or the like. Since the battery is replenished when necessary, the machine is compact and economical construction machine that can be used even in small places.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an electric motor drive as an embodiment of an electric ground auger of the present invention.

FIG. 2 is a plan view showing an arrangement of the devices.

FIG. 3 is a block diagram showing a configuration of a hydraulic pump drive as an embodiment of the electric earth auger according to the second aspect of the present invention.

FIG. 4 is a side view showing an entire conventional electric ground auger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base machine 2 ... Leader 3 ... Guide rail 5 ... Auger drive device 6 ... Auger screw 8 ... Power generation device 11 ... Engine 12 ... Generator 13 ... Gear device 14, 15 ... Hydraulic pump 16 ... Converter 17 ... Inverter 18 ... Storage battery DESCRIPTION OF SYMBOLS 20 ... Electric motor 21 ... Load detection means 25 ... AC machine 26 ... Switching device 31 ... Operator cab 32,33,34 ... Winch 35,36 ... Outrigger

Claims (4)

[Claims] An electric earth auger having an electric motor for driving an auger screw or the like in a reader standing in front of a base machine, wherein a generator driven by an engine of the base machine is provided, and the generator is connected to a converter and an inverter. And a storage battery to be charged by the generator is provided through the converter, and the power of the storage battery is supplied to the motor when the power of the generator is insufficient. Electric earth auger. 2. An electric earth auger having an electric motor for driving an auger screw or the like on a reader standing upright in front of a base machine, wherein an AC machine driven by an engine of the base machine is provided, and the AC machine is connected to a converter and an inverter. And a storage battery charged by the AC machine is provided through the converter, and a load detecting means for the engine is provided, and the engine is overloaded by a hydraulic pump driven by the engine. An electric earth auger, characterized in that a conversion means for connecting the AC machine to an inverter is provided in such a case, and the drive of the hydraulic pump is supplemented as an electric motor for driving the AC machine with the power of a storage battery. 3. An electric earth auger according to claim 1, further comprising an engine load detecting means for reducing the output of the generator so that the engine load does not exceed a predetermined value. 4. The electric earth auger according to claim 1, wherein the storage battery is mounted on a rear portion of the base machine and its mass is used as a counterweight.