KR20120111004A - Electric excavator system - Google Patents

Abstract

PURPOSE: An electric excavator system is provided to efficiently use a work space by detachably coupling an electric power supply unit and an electric power receiving unit to each other. CONSTITUTION: An electric excavator system comprises an electric power supply unit(100) and an electric power receiving unit(200). The electric power supply unit is composed of a power supply box(110), a cable drum(120), a drum drive unit(122), and a cable guide(130). The electric power receiving unit is composed of a cable connector, a controller(240), one or more storage batteries(210a,210b,210c), an overcharge prevention unit(212), a charge volume detection unit(214), an inverter(220), an alarm unit(250), and a changeover switch. A cable from the electric power supply unit is connected and disconnected to/from the cable connector and the controller. [Reference numerals] (110) Power supply box; (120) Cable drum; (122) Drum drive unit; (130) Cable guide; (210a,210b,210c) Storage battery; (212) Overcharge prevention unit; (214) Charge volume detection unit; (220) Inverter; (230) Traveling motor generator; (232) Turning motor generator; (240) Controller; (250) Alarm unit; (260) Hydraulic pump; (270) Hydraulic control valve; (274) Boom cylinder; (276) Arm cylinder; (278) Bucket cylinder; (280) Changeover switch; (AA) External power source; (BB) Explanatory notes; (CC) Mechanical coupling; (DD) Electrical coupling; (EE) Hydraulic motion

Description

Electric Excavator System {ELECTRIC EXCAVATOR SYSTEM}

The present invention relates to an electric excavator system, and more particularly, a plurality of storage batteries, especially thin-film supercapacitors, in an electric excavator system improved to be able to work remotely without space limitation because the power supply unit and the power receiver are separated. The present invention relates to an electric excavator system that is improved to perform long-distance work using a.

In general, an excavator is a construction machine with various work functions, such as excavation work to dig or fill the ground during construction and civil works, breaker work such as soil and rock crushing, compactor work such as soil compaction, and crusher work such as cutting. Say.

Such an excavator is usually equipped with an engine such as a diesel engine to obtain driving power, and uses the power of the engine to drive a hydraulic pump, and supply hydraulic oil discharged from the hydraulic pump to a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder. As a result, each work part such as a traveling crawler or tire rotation, a boom, an arm or a bucket is operated.

Since such a well-known excavator is equipped with an engine such as a diesel engine, it has the advantage of being able to work freely without being restricted in the work place.

However, diesel, which is a fossil fuel, is gradually being depleted, and the necessity of alternative energy is seriously raised, and fuel costs are high, and fuel consumption is particularly high due to the peculiarity of heavy equipment.

As part of solving this problem, an electric excavator using electric energy has been disclosed.

The disclosed electric excavator, for example, by replacing the engine for driving the excavator with an electric motor, as shown in the example of FIG. 1 and by supplying the power for driving the motor from an external power source through the cable 10 to reduce the fuel cost by more than 70% For example, an external power box 20, a cable drum 22 to wind the cable 10, and a cable guide 24 to pivot the cable 10 so as to supply power from the outside. And an induction guide 30 installed in the excavator to guide the cable 10 guided out through the cable guide 24 to the excavator safely.

Therefore, the driving of the excavator uses an engine-powered motor mounted on the excavator, and the various work functions of the excavator use the hydraulic operation through the hydraulic pump as it is, but control the driving of the hydraulic pump by an electric motor. The function was performed as is.

However, since the electric excavator is structured to be powered using the cable 10, the range in which the excavator can operate is limited.

That is, since the work can be performed only within the range of the cable 10, the working radius is very limited, and the remote work is not possible, which causes a lot of inconveniences.

In addition, even if the remote operation is possible using the battery, there is a disadvantage that it is difficult to work for a long time because the capacity of the battery has a limit.

The present invention was created in view of the above-mentioned problems in the prior art as described above. In the cable type electric excavator, the operating range of the excavator is extended to a farther distance than the cable, and thus the working range can be expanded. In addition to maximizing and switching the use of a plurality of batteries, it provides an electric excavator system that expands the application range of the batteries, and allows the supercapacitors with large charging capacity to work stably for a longer time in long distance work. There is a main purpose.

The present invention is a means for achieving the above object, the hydraulic pump is driven by the motor generator under the control of the controller as the driving power and the turning power, and the flow of the hydraulic oil by the hydraulic pump to control the boom In the electric excavator that can be driven by the operation of the drive, the drive of the arm, the operation of the bucket, the external power input is input to the charging voltage, the power box including a plurality of control buttons, the cable provided to wind or unwind the power transmission cable A power supply unit comprising a drum, a drum driving unit for controlling rotation of the cable drum, and a cable guide connected to the power box and guiding the charging cable wound around the cable drum so as not to be tangled or twisted; A cable connector to which the cable of the power supply unit can be connected / disconnected, a motor generator, and a controller; A battery that charges the power supplied by the regenerative braking of the electric power and the motor generator, An overcharge preventing unit connected to the battery and preventing overcharging under the control of the controller, The battery is connected to the battery and detects the potential difference of the battery and outputs it to the controller. An electric power consisting of a storage capacity detection unit, an inverter connected to the storage battery and an inverter which converts the DC power of the storage battery into an AC power supply under the control of the controller and supplies it to an electric generator, and an alarm unit that is connected to the controller and sends an alarm when the detection potential of the battery is lower than the reference potential. And a storage unit, wherein the storage battery is a hybrid storage battery in which a thin film battery and a supercapacitor are combined, a plurality of which is stacked up and down to form a unit, and a plurality of units are provided, and the potential of each storage battery is a reference potential. When lower, between the battery and the inverter under the control of the controller. It provides an electric excavator system, characterized in that the switch is further installed to switch the connection.

In this case, in the hybrid storage battery, a current collector is formed on a substrate, and a lower electrode, an electrolyte, and an upper electrode are respectively formed on one side of the insulator, and a cathode, an electrolyte, and an anode are respectively formed on the other side of the current collector. On top of that, there is also a feature in that the structure in which the current collector is formed again as one unit unit.

According to the present invention, by separating the power supply unit and the power receiving unit can remove the constraints of the work space, improve the work efficiency, eco-friendly, reduce fuel costs, switching a large number of units with a large capacity supercapacitor stacked into a storage battery By using it, it is possible to obtain a long distance smoothly.

1 is an exemplary view of a conventional cable type electric excavator.
2 is a block diagram illustrating the construction of the electric excavator system according to the present invention.
3 is an exemplary partial cross-sectional view showing an example of a battery for an electric excavator using a supercapacitor according to the present invention.
Figure 4 is an exemplary circuit diagram showing a charging device of a battery for an electric excavator using a supercapacitor according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The electric excavator system according to the present invention has the concept of the conventional cable type electric excavator described above, including the charging concept, and receives power when needed, uses charged power when working, and secures the voltage required for the work. It is configured to detect whether it is doing so and to charge it when necessary.

In this regard, reference is made to FIG. 2, which shows a block diagram of an electric excavator system according to the invention.

As shown in Figure 2, the electric excavator system according to the present invention is configured to separate the power supply unit 100 and the power receiver 200.

At this time, the power supply unit 100 is installed in a place for supplying power from the outside as before, the power receiver 200 is installed in the excavator body.

In addition, the power receiver 200 is provided with a cable connector (meaning a plug and a socket) to be connected to the power supply unit 100.

More specifically, as shown in FIG. 2, the power supply unit 100 includes a power supply box 110, a cable drum 120, and a drum driver 122 and a cable guide 130 that control rotation of the cable drum 120. ).

In this case, the power box 110 is provided with a plurality of control switches, so that the external power is connected to supply the necessary power supplied from the external power source to the power receiver 200 when connected to the power receiver 200. It is designed.

In addition, the power supply unit 100 may be installed in plural as necessary, if a large working radius is installed a plurality at appropriate intervals to provide ease of connection through the power receiver 200 to further improve workability. Can be.

In addition, the cable drum 120 facilitates cable management to a short distance as well as to a long distance while winding or releasing a cable (Cable) for transmitting power controlled through the power box 110.

In this case, the cable drum 120 may be driven by a power source, the drive motor may be a drive motor, it may also be controlled by the drum drive unit (122).

In addition, the cable guide 130 is a structure that is guided so that the cable is not tangled or twisted power supply may have the form of the existing cable guide illustrated in FIG.

In this case, the cable guide 130 guides the cable drawn out from the cable drum 120 in which the cable is wound so as to smoothly withdraw the cable to a predetermined length range.

On the other hand, the power receiving unit 200 includes a driving motor generator 230 as a driving driving source, the driving motor generator 230 is in the form of AC power in the state in which the DC power is switched to the AC power through the inverter 220 Will be powered by

In this case, the inverter 220 is controlled by the controller 240.

In addition, the driving motor generator 230 is connected to the hydraulic pump 260 to be controlled through the controller 240.

In addition, the power supply unit 200 according to the present invention further includes a swing motor generator 232 capable of rotating the excavator body mounted with the boom 360 ° with respect to the main body.

In addition, they take the form of an electric motor and a generator to obtain electrical energy through regenerative braking, and the regenerative electricity obtained through regenerative braking is recovered and stored in the battery 210.

As such, since the regenerative braking can be used to accumulate electricity to the storage battery 210, it is possible to reduce heat generation due to driving and to recycle energy.

Of course, the swing motor generator 232 is also controlled by the controller 240.

In addition, the controller 240 may include a predetermined memory.

In addition, a hydraulic control valve 270 is connected to the hydraulic pump 260, and the hydraulic oil discharged by the hydraulic pump 260 is boom cylinder 274 and an arm cylinder according to the control sequence of the hydraulic control valve 270. 276, the bucket cylinder 278 is driven.

That is, since only the drive of the hydraulic pump 260 is electrically coupled, the controller 240 is controlled by the controller 240 to selectively receive the driving force of the driving motor generator 230, but the hydraulic oil generated by the driving of the hydraulic pump 260 thereafter. The hydraulic circuit associated with the supply of is made as before through the opening and closing control of the hydraulic control valve 270.

And, the storage battery (210a, 210b, 210c) for supplying power to the driving motor generator 230 is provided, because the storage battery (210a, 210b, 210c) is a direct current type, as described above, through the inverter 220 The driving motor generator 230 is supplied with alternating DC power to AC power, and when a plurality of installed and charged voltages are lowered to a predetermined level, that is, the reference potential for working, the switch switch 280 is used to change to another storage battery. Include.

In this case, the changeover switch 280 is installed between the inverter 220 and the storage batteries 210a, 210b, and 210c, and is controlled by the controller 240.

Here, the three storage batteries 210a, 210b, 210c has been described as an example, but this is only a preferred embodiment and can be installed more of course.

Therefore, when three or more batteries are used while changing a single battery, the working time can be extended by that amount, and the working efficiency can be improved for a long time at a long distance.

In addition, the storage batteries 210a, 210b, and 210c are connected to the cable drawn out through the cable guide 130 and the cable connector and configured to be chargeable.

In other words, in a state in which a proper amount of power is charged, the driving motor generator 230 may be driven by being separated from the power supply unit 100 to freely expand and expand the working range of the excavator.

However, as described above, when the charged power falls below a certain level, it is difficult to perform the operation of the excavator, so it can be solved by checking the connection in advance and switching the connection to another battery having a sufficient amount of storage. Accordingly, the work efficiency does not need to be moved back to the power supply unit 100 for charging during the remote work.

To this end, in the present invention, the storage capacity detection unit 214 is further installed in the storage batteries 210a, 210b, and 210c, and at the same time, the overcharge preventing unit 212 can prevent damage to the storage batteries 210a, 210b and 210c due to overcharging. ) Is installed including more.

At this time, the overcharge prevention unit 212 and the power storage detection unit 214 are all connected to the controller 240 is configured to be controlled by the controller 240, these overcharge protection unit 212 and the power storage detection unit to prevent overcharge It is preferable to have a kind of circuit form, such as a circuit and a capacitance detection circuit.

In addition, the capacitance detecting unit 214 detects the internal resistance that changes according to SOC (State Of Charge) and temperature of the batteries 210a, 210b, and 210c, and a method of estimating potential by estimating an electric potential. The amount of electricity stored in the 210a, 210b, and 210c, that is, the potential can be detected. The simplest method detects the voltages of both ends of the batteries 210a, 210b, and 210c, and transmits them to the controller 240, and the controller 240. Is preferably configured to check and control the charging by comparing the received detection potential with a reference potential required for driving.

In addition, when it is determined that the potential of the battery currently being used is lower than the reference potential through the storage amount detecting unit 214, the changeover switch 280 is connected to the inverter 220 with an adjacent storage battery having sufficient storage capacity under the control of the controller 240. Switch.

In particular, in the present invention, in addition to the switching function of the batteries 210a, 210b and 210c as described above, the supercapacitor itself is applied to the supercapacitor so as to enable a stable operation for a long time during long distance work. Can be produced in one form.

At this time, a supercapacitor is a large-capacity capacitor developed in Japan in the 1980s, as is well known, and is small in size, light in weight, can be charged in a short time, and has a specific capacitance (F / g) compared to an electrostatic capacitor. It is an electrochemical capacitor that is 100 to 1000 times better.

In the present invention, a hybrid storage battery manufactured by mixing the existing thin film battery technology and a supercapacitor, in particular, has a form of forming a unit, that is, a storage battery by stacking them in multiple layers.

In this case, in the hybrid storage battery, as illustrated in FIG. 3, the current collector 304 is formed on the substrate 302, and the lower electrode 308 and the electrolyte 312 are formed on one side of the insulator 320. And the upper electrode 316 are formed, respectively, the cathode 306, the electrolyte 310 and the anode 314 are formed on the other side, and the current collector 318 is formed on the top.

Such a hybrid structure allows the supercapacitor and the battery to be formed in a thin film form on a single substrate, and can be usefully applied to various microdevices by structurally forming them on a single chip while maximizing their advantages.

Particularly, in the present invention, a plurality of hybrid storage batteries having such a structure are stacked to form one unit, and when charging, the battery can be charged through a charging circuit as shown in FIG. This charging circuit is controlled by the controller 240 described above.

The illustrated charging circuit will be briefly described. A switch unit 402, one end of which is connected in series with a positive electrode of a hybrid battery, for intercepting power supplied from the hybrid battery, and the other end (node A) and ground of the switch unit 402. It may be configured as a charging terminal unit 404 connected to (GND), and may further include the function of the power storage detection unit 214 described above.

For example, the capacitance detection unit 214 may have first, second, and third display units 410, 420, 430 so as to be connected in parallel to the charging terminal unit 404 to display the hybrid battery charging state step by step. 410 is composed of the first light emitting means D1 connected forward between the voltage distribution point N1 of the first resistor voltage divider R1 and R2 connected between the node A and the ground, and the ground. The display unit 420 is composed of the voltage distribution point N2 of the second resistor voltage divider R3 and R4 connected between the node A and the ground and the second light emitting means D2 connected forwardly between the ground. The third display unit 430 includes a Zener diode ZD connected in a reverse direction between the voltage distribution point N3 of the third resistor voltage divider R5 and R6 connected between the node A and the ground and the base of the NPN transistor TR. Wherein the collector of the transistor is connected to the node A and the emitter It may be configured in the forward connected between the third round light-emitting means (D3).

Thus, the state of charge can be displayed step by step.

Meanwhile, an alarm unit 250 is connected to the controller 240.

The alarm unit 250 is preferably configured to flash the warning light while emitting an alarm sound so that the excavator driver can see visually.

In addition, the alarm unit 250 is operated under the control of the controller 240 when the detection potential of the storage batteries 210a, 210b, 210c of the power storage detection unit 214 does not reach the reference potential. Is driven to the power supply unit 100 to connect the cable provided in the power supply unit 100 to the power receiver 200 to perform the charging operation.

In this case, the alarm unit 250 may generate an alarm for each discharge of each battery, and may be configured to generate an alarm when all the batteries are discharged. Preferably, only the warning lamp flashes during discharge of each battery. When all of the batteries are discharged, it is particularly preferable to generate a warning light and an alarm sound so that the batteries can be recognized visually.

In addition, the term "discharge" described in the present invention is not defined as a discharge concept commonly used, but is defined as meaning when the potential of the battery falls below a reference potential (a proper potential required for driving an excavator).

The present invention having such a configuration has the following operational relationship.

First, when the working radius is not far from the power supply unit 100 and is within the length of the cable, the power supply unit 100 and the power receiver unit through the cable connector without having to separate the power supply unit 100 and the power receiver 200. While maintaining the connection state 200, the work that can be done through the electric excavator, such as excavation work, breaker work, crusher work, etc. are performed.

In this case, since the power is continuously supplied through the power supply unit 100, the driving power and the working power (for driving the hydraulic pump) are sufficient without sufficient force.

On the other hand, if the working radius is out of the cable length is supplied with sufficient power from the power supply unit 100 to sufficiently charge the power required for the storage batteries (210a, 210b, 210c) provided in the power receiving unit 200 or already charged state To be in.

Thus, when charging is complete, the cable connector is disconnected so that the power supply unit 100 and the power receiver 200 are separated.

In particular, when using a hybrid storage battery is applied to the supercapacitor according to the present invention, the storage capacity is increased, can be used for a long time, it is very useful for long distance work, it is possible to shorten the charging time.

Then, the excavator is driven by using the power stored in the storage battery (210a, 210b, 210c), and after moving to the working place to drive the hydraulic pump 260 under the control of the controller 240 to perform the necessary work. .

In addition, when the warning light flashes through the alarm unit 250 during operation, the driver only needs to recognize that the battery is changing.

At the same time, the changeover switch 280 switches the connection between the storage battery and the inverter 220 to a new storage battery under the control of the controller 240.

Then, since the excavator can always be supplied with a power source above the reference potential, there is no problem in driving the driving motor generator 230, and thus, a long distance operation can be performed.

If the audio-visual alarm is generated through the alarm unit 250 even after the operation continues or during the operation, the driver recognizes that the battery needs to be stored, and drives the excavator toward the power supply unit 100 to connect the cable connector. By connecting the power supplied from the power supply unit 100 to charge the storage battery (210a, 210b, 210c), and if sufficient power storage is done again disconnect the cable and then move to the work place to work.

At this time, if a plurality of power supply unit 100 is installed in accordance with the working radius, the time required to move the excavator for charging, thereby reducing the charging time has the advantage that the work efficiency is improved.

As such, the electric excavator according to the present invention may drive the hydraulic motor 260 by driving the driving motor generator 230 replacing the engine by using the storage batteries 210a, 210b, and 210c. It is possible to perform various tasks that can improve the work efficiency and save energy.

First of all, by using a plurality of storage batteries (210a, 210b, 210c) can work for a long time even in the long-distance work has the advantage of significantly improved work efficiency.

100: power supply unit 110: power box
120: cable drum 200: power receiver
210a, 210b, 210c: battery 220: inverter
230: driving motor generator 240: controller
250: alarm unit 260: hydraulic pump
270: hydraulic control valve 280: changeover switch

Claims (2)

An electric excavator system comprising a power supply and a power receiver;
The power supply unit is composed of a power box, a cable drum, a drum drive unit and a cable guide;
The power receiver includes a cable connector and a controller to which the cable of the power supply unit can be connected / disconnected, and comprises at least one battery, an overcharge preventing unit, a capacitance detection unit, an inverter and an alarm unit;
The storage battery is a hybrid storage battery in which a thin film battery and a supercapacitor are combined, and a plurality of batteries are stacked up and down to form a single unit, and a plurality of units are provided, and when the potential of each battery is lower than the reference potential, An electric excavator system further comprising a changeover switch for switching the connection between the battery and the inverter under control. The method according to claim 1;
In the hybrid storage battery, a current collector is formed on a substrate, and a lower electrode, an electrolyte, and an upper electrode are formed on one side of the insulator, respectively, and a cathode, an electrolyte, and an anode are formed on the other side of the current collector. At the top, the electric excavator system, characterized in that the current collector is formed in one unit unit.

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