KR101936206B1 - Excavator system for hydraulic hybrid having regenerated energy using motor-generator - Google Patents

Abstract

The present invention relates to an energy recovery tandem hydraulic hybrid excavator system using a motor-generator, and more particularly, to an energy recovery tandem hydraulic hybrid excavator system using a motor-generator, A valve module and a hydraulic drive unit including a hydraulic actuator provided for linear motion or rotary motion, and a valve module for controlling the flow rate stored in the hydraulic pressure chamber and distributing the flow rate to the hydraulic actuator; And an energy regenerating unit that receives and stores energy regenerated from the hydraulic driving unit and supplies the flow rate to the hydraulic driving unit when necessary, wherein the energy regenerating unit includes a motor-generator driven by a motor or a generator, A hydraulic pump-motor connected to the generator and driven by a hydraulic pump or motor, and a power storage unit for storing electric energy produced when the motor-generator is driven by the generator. According to the above configuration, The engine operates continuously in the vicinity of the most efficient region on the efficiency map, thereby enhancing the efficiency of the engine, enabling self-operation using the regenerative energy of the hydraulic drive, and operating as an auxiliary accumulator There is an effect that a stable and smooth operation of the hydraulic drive unit can be achieved through the regenerative unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid hydraulic excavator,

The present invention can improve the efficiency of the engine, enable self-operation using the regenerative energy of the hydraulic drive unit, and provide a stable and smooth operation of the hydraulic drive unit through the energy regeneration unit even when the load is suddenly increased. Tandem hydraulic hybrid excavator system.

Generally, heavy construction equipments are heavy equipment used for various large construction such as civil works, and excavators are among them.

Conventional excavators are designed to perform heavy load operations such as excavation or filling work as well as relatively light work such as floor picking. Heavy equipment such as excavators can be powered by various hydraulic devices. .

Such an excavator or a hydraulic device used for other heavy equipment is disclosed in Published Unexamined Patent Application Nos. 10-2011-0077061, 10-1301234, 10-0464761, 10-2014-0147551, etc. .

The excavator consists largely of an upper revolving body, a lower driving body, and working means such as a boom / arm / bucket. The engine and the pump supply the flow rate directly to the actuator side to which the boom / arm / bucket is connected.

The average output required by an excavator is very low compared to the peak output, but there is a problem that the output of the engine must change from time to time in order to supply all the necessary output during direct operation through the direct flow supply.

Further, since the output of the engine must be changed from time to time in accordance with the load of the hydraulic driving unit which changes instantaneously, the efficiency of the engine is very low and a stable and smooth hydraulic driving unit can not be operated.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-described problems, and it is an object of the present invention to provide an engine control apparatus and a control method thereof, which can continuously increase the efficiency of the engine, The present invention has been made in view of the above problems, and it is an object of the present invention to provide an energy recovery tandem hydraulic hybrid excavator system using a motor-generator capable of operating a stable and smooth hydraulic drive unit through an energy regenerating unit that operates as an auxiliary accumulator even in a sudden increase in load.

According to the present invention, there is provided a hydraulic system comprising: a hydraulic pressure charging unit for generating and storing a flow rate; A valve module and a hydraulic drive unit including a hydraulic actuator provided for linear motion or rotary motion, and a valve module for controlling the flow rate stored in the hydraulic pressure chamber and distributing the flow rate to the hydraulic actuator; And an energy regenerating unit that receives and stores energy regenerated from the hydraulic driving unit and supplies the flow rate to the hydraulic driving unit when necessary, wherein the energy regenerating unit includes a motor-generator driven by a motor or a generator, A hydraulic pump-motor connected to the generator, which can be driven by a hydraulic pump or a motor, and a power storage unit for storing electric energy produced when the motor-generator is driven by the generator.

In the present invention, when energy to be regenerated from the hydraulic driving unit is received and stored, the hydraulic pump-motor receives energy regenerated from the hydraulic driving unit and drives the hydraulic pump-motor as a motor. From the hydraulic pump- The motor-generator is driven as a motor, and when necessary, the motor-generator receives electric energy stored in the power storage unit to drive the motor-generator as a motor, and when the flow rate is supplied to the hydraulic drive unit, And the hydraulic pump-motor is driven by a hydraulic pump after receiving the rotational force from the generator.

In the present invention, the hydraulic pump-motor is driven by a hydraulic pump, and the flow rate is supplied to the hydraulic drive unit.

In the present invention, the hydraulic pump-motor is driven by a hydraulic pump, and the flow rate is supplied to the main circuit constituting the valve module and the hydraulic drive unit.

In the present invention, it is preferable that the hydraulic pressure charging unit includes an engine, a main pump that receives the rotational force of the engine to generate a flow rate, an accumulator that stores a flow rate generated by the main pump, And a switching valve connected to the switching valve.

In the present invention, the hydraulic pump-motor is driven by a hydraulic pump, and the flow rate is supplied to the front side of the main pump.

In the present invention, the hydraulic drive unit may include a swing motor for rotating the upper body, a boom cylinder for operation of the boom, an arm cylinder for operation of the arm, and a bucket cylinder for operation of the bucket, The valve module is characterized by a combination of independent metering valves.

In the present invention, the energy regenerated from the hydraulic driving unit is kinetic energy due to gravitational potential energy and / or rotational moment of inertia.

According to the energy recovery tandem hydraulic hybrid excavator system using the motor-generator of the present invention, the following effects can be obtained.

The engine and the main pump are completely separated from the hydraulic drive unit and are used solely for charging the accumulator. Thus, the load of the hydraulic drive unit, which changes occasionally, corresponds only to the hydraulic energy charged in the accumulator, By continuously operating in the vicinity, the efficiency of the engine can be increased.

The energy recovery unit that receives and stores the energy regenerated from the hydraulic drive unit and supplies the flow rate to the hydraulic drive unit when necessary is mounted so that the self-operation can be performed using the regenerative energy of the hydraulic drive unit.

Accordingly, when the required power width is large, stable and smooth operation of the hydraulic drive unit is possible through the energy regeneration unit operated as an auxiliary accumulator even when the supply of the flow rate is insufficient only by the accumulator.

This makes it possible to reduce the size of the engine and the main accumulator.

Furthermore, the regenerative energy of the hydraulic drive unit can be stored in an electric form and utilized variously.

On the other hand, since the valve module of each hydraulic drive unit is constituted by a combination of independent metering valves, it is possible to drive the independent hydraulic drive unit with one main accumulator, thereby increasing energy efficiency and maximizing energy recovery.

1 is a conceptual diagram of an energy recovery tandem hydraulic hybrid excavator system using a motor-generator according to a preferred embodiment of the present invention.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a hydraulic excavator and a hydraulic excavator.
Figs. 3 to 5 show embodiments in which the flow rate supplied when the hydraulic pump-motor is driven by the hydraulic pump can be used. Fig.
6 is a hydraulic circuit diagram showing a detailed configuration of a valve module constituted by an independent metering valve combination;
Figures 7 to 11 illustrate the basic operating mode of Figure 6;
12 is a table showing whether the valves are opened or closed according to the respective operation modes of Figs. 7 to 11. Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately The present invention should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

As shown in FIGS. 1 and 2, the energy regenerating tandem hydraulic hybrid excavator system using the motor-generator according to the preferred embodiment of the present invention includes the hydraulic charging unit 100, the valve module and the hydraulic driving unit 200, (300).

The hydraulic pressure generating unit 100 generates and stores a flow rate and includes an engine 110, a main pump 130, an accumulator 150, and a switching valve 170 as shown in FIG.

The engine 110 generally combusts fossil fuels (gasoline, light oil or gas) to generate the basic power required for driving. Thus, the engine 110 generates power by burning the fuel, and rotates the drive shaft through the generated power.

The main pump 130 receives the rotational force of the engine 110 to generate a flow rate. The main pump 130 may be a variable displacement hydraulic pump in which oil flows in only one direction.

The accumulator 150 stores the flow rate generated by the main pump 130, and is preferably a large capacity accumulator 150.

The switching valve 170 operates to control the flow rate storage or use of the accumulator 150. That is, when the switching valve 170 is closed, the supply of the flow rate to the main circuit constituting the valve module and the hydraulic drive unit 200 is blocked, and the flow rate generated by the main pump 130 is stored in the accumulator 150 . On the contrary, when the switching valve 170 is opened, the flow rate is supplied to the main circuit constituting the valve module and the hydraulic driving part 200, so that the flow rate stored in the accumulator 150 can be used.

A pressure control valve 140 such as a relief valve may be connected between the main pump 130 and the oil storage tank 131. When the pressure control valve 140 is connected, when the pressure of the hydraulic circuit reaches the set pressure, part or all of the fluid can be discharged to keep the pressure in the circuit below the set value.

A check valve 145 is connected between the main pump 130 and the accumulator 150 so that the flow rate stored in the accumulator 150 does not flow back to the main pump 130 side.

Thus, in the present invention, the engine 110 and the main pump 130 are completely separated from the hydraulic drive unit 210 and are used solely for the purpose of charging the accumulator 150. The load of the hydraulic driving unit 210 which changes momentarily corresponds to the use of only the hydraulic energy charged in the accumulator 150 and the engine 110 continuously operates in the vicinity of the most efficient region on the efficiency map, The efficiency can be increased.

2, the valve module and the hydraulic drive unit 200 include a hydraulic drive unit 210 provided for linear motion or rotational motion, and a control unit 210 for controlling the flow rate of the hydraulic fluid supplied from the hydraulic drive unit 210, And a valve module (250) for distributing the fluid to the valve module (250).

The hydraulic drive unit 210 provided for the linear motion or the rotary motion includes the swing motor 211, the boom cylinder 212, the arm cylinder 213, and the bucket cylinder 214.

The swing motor 211 is provided for rotating the upper body and may be formed of a variable displacement hydraulic motor in which oil flows in both directions.

A first direction switching valve 231 is connected to a hydraulic circuit to which a flow rate is supplied from the accumulator 150 to a hydraulic circuit to which the swing motor 211 is connected. The first directional control valve 231 operates to receive the flow rate from the accumulator 150 or shut off the flow rate. That is, when the first direction switching valve 231 is opened, the flow rate is supplied from the accumulator 150, so that the flow rate can be supplied to the swing motor 211. Conversely, if the first directional control valve 231 is closed, the flow rate supplied from the accumulator 150 can be shut off.

An A port direction switching valve 221 is connected between the first direction switching valve 231 and the swing motor 211. The A port direction switching valve 221 operates to supply the flow rate due to the regenerative energy generated in the swing motor to the A port or the flow rate to the A port from the energy regenerating unit 300 and supply the flow rate to the swing motor 211 .

The boom cylinder 212 is provided for operation of a boom, and may be formed of a hydraulic cylinder.

The B port direction switching valve 222 is connected to the hydraulic circuit to which the boom cylinder 212 is connected. The B port direction switching valve 222 is connected to the port B through the regeneration energy generated from the boom cylinder 212 to the port B or to the port B through the energy regenerating unit 300 to connect the valve module 250 Circuit.

The arm cylinder 213 is provided for operation of an arm and may be formed of a hydraulic cylinder.

A C port direction switching valve 223 is connected to the hydraulic circuit to which the arm cylinder 213 is connected.

The C port direction switching valve 223 is operated to receive the flow rate from the energy regenerating unit 300 to the C port or shut off the flow rate. That is, when the C port direction switching valve 223 is opened, the flow rate from the energy regenerating unit 300 to the C port can be supplied to the circuit connected to the valve module 250. On the contrary, when the C port direction switching valve 223 is closed, the flow rate supplied from the energy regenerating unit 300 to the C port can be shut off.

The bucket cylinder 214 is provided for operation of a bucket and may be formed of a hydraulic cylinder.

A D port direction switching valve 223 is connected to the hydraulic circuit to which the bucket cylinder 214 is connected.

D port direction switching valve 224 is operated to receive the flow rate from the energy regenerating unit 300 to the D port or shut off the flow rate. That is, when the D port direction switching valve 224 is opened, the flow rate from the energy regenerating unit 300 to the D port can be supplied to the circuit connected to the valve module 250. On the contrary, when the D port direction switching valve 224 is closed, the flow rate supplied from the energy regenerating unit 300 to the D port can be shut off.

The valve module 250 that controls the flow rate stored in the hydraulic pressure charging unit 100 and distributes the hydraulic pressure to the hydraulic pressure drive unit 210 is composed of a combination of independent metering valves (IMV) . When the valve module 250 is constituted by an independent metering valve combination, precise motion control can be performed, the efficiency of the system can be increased, and efficient energy regeneration is possible.

The valve module 250 constituted by the independent metering valve combination includes a circuit for connecting both ends of the boom cylinder 212, a circuit for connecting both ends of the arm cylinder 213, a bucket cylinder 214 Respectively, on the circuit connecting the opposite ends of the circuit board.

The detailed configuration of the valve module 250 composed of the independent metering valve combination is shown in Fig. 6, and the operating principle is shown in Figs. 7 to 11. 6 to 11 illustrate the valve module 250 connected on the circuit connecting both ends of the boom cylinder 212. The valve module 250 shown in Figs. A circuit connecting both ends of the bucket cylinder 214, and a valve module 250 connected on a circuit connecting both ends of the bucket cylinder 214. [

According to Fig. 6, four valves 251, 252, 253 and 254 are connected on the hydraulic circuit between the boom cylinder 212 and both ends and the hydraulic pump-motor 330. 6, four valves 251, 252, 253 and 254 are shown connected to the hydraulic circuit between the boom cylinder 212 and both ends and the hydraulic pump-motor 330 for the sake of convenience. However, strictly speaking, Four valves 251, 252, 253 and 254 are connected on the hydraulic circuit between the boom cylinder 212 and the C port connected to the energy regenerator 300 including the hydraulic pump-motor 330, .

The four valves 251, 252, 253 and 254 are direction change valves. For convenience, reference numeral 251 denotes a Ksa valve, reference numeral 252 denotes a Ksb valve, reference numeral 253 denotes a Kat valve, and reference numeral 254 denotes a Kbt valve.

The combination of the four valves 251, 252, 253, and 254 that are operated by the electrical signals in this manner allows the power expansion mode PE, the power shrink mode PR, the high pressure side playback expansion mode HSRE, It is possible to operate in five modes of the expansion mode LSRE and the low pressure side regeneration and contraction mode LSRR and whether or not the four valves 251, 252, 253 and 254 according to the respective modes are opened or closed is shown in the table of Fig. .

The description of each operation mode is as follows.

7, the high-pressure hydraulic fluid supplied from the hydraulic pump-motor 330 acting as a pump is supplied to the boom cylinder 212 via the Ksa valve 251, And the piston rod is extended outward, and the hydraulic fluid in the load chamber enters the oil reservoir tank 257 through the Kbt valve 254. In this case, In this mode, the Ksb valve 252 and the Kat valve 253 are kept closed.

Next, in the powered retraction (PR), the PR mode operates on the same principle as the PE mode, as shown in Fig. 8, except that the direction of movement of the piston is opposite. That is, the high-pressure hydraulic fluid supplied from the hydraulic pump-motor 330 acting as a pump enters the load chamber of the boom cylinder 212 through the Ksb valve 252 to push the piston, thereby causing the piston rod to contract, The hydraulic oil enters the oil storage tank 257 through the Kat valve 253. In this mode, the Ksa valve 251 and the Kbt valve 254 are kept closed.

9, when the pressures of the head chamber and the cylinder rod chamber of the boom cylinder 212 are equal to each other, due to the difference in the front and rear surface area of the piston, the high side regeneration extension (HSRE) The piston rod moves in the direction to expand outward. In other words, the operating fluid discharged from the cylinder rod chamber moves to the cylinder head chamber via the Ksb valve 252 and the Ksa valve 251. [ Since the volume of the cylinder rod chamber and the cylinder head chamber is different by the load volume in the cylinder, the hydraulic pump-motor 330, which operates as a pump, must compensate for the insufficient flow rate. In this mode, the name "high side" is used because the hydraulic oil is regenerated through the high-pressure flow path connected to the hydraulic pump-motor 330 operating as a pump.

Next, as shown in FIG. 10, the low side regeneration extension (LSRE) can be applied when an external force acts in the direction in which the piston rod extends. That is, the operating oil having a high pressure formed in the cylinder rod chamber is pushed by the external force and moved to the oil passage connected to the oil storage tank 257 through the Kbt valve 254. At this time, a low oil pressure is formed in the head chamber. When the Kat valve 253 is opened, the hydraulic oil flows into the cylinder head chamber having a low pressure. Since the volume of the cylinder rod chamber and the cylinder head chamber is different by the load volume in the boom cylinder 212, the hydraulic pump-motor 330, which operates as a pump, must compensate for the insufficient flow rate. In this mode, the name "low side" is used because the hydraulic oil is regenerated through the low-pressure passage connected to the oil storage tank 257.

Finally, the low side regeneration retraction (LSRR) can be applied when an external force acts in the direction in which the piston rod contracts, as shown in Fig. The hydraulic oil in which a high pressure is generated in the cylinder head chamber by the external force flows through the Kat valve 253 to the oil passage connected to the oil storage tank 257. At this time, when the Kbt valve 254 is opened, since the pressure of the cylinder head chamber is low, the operating oil does not go to the oil storage tank 257 but flows into the cylinder head chamber. In this mode, the hydraulic fluid moves from the cylinder head chamber to the load chamber, so that the hydraulic fluid remains as much as the volume difference between the two chambers. The hydraulic oil exceeding the volume of the load chamber returns to the oil storage tank 257 through the check valve 255. [ Since it is possible to operate without the supply of the hydraulic oil, only the hydraulic pump-motor 330 of the three regeneration modes can operate without work.

The energy regenerating unit 300 receives and stores the energy regenerated from the hydraulic driving unit 210 and controls the hydraulic driving unit 210 as an auxiliary power source when the operation of the hydraulic driving unit 210 is complicated due to the flow rate of the accumulator 150, 210).

The energy regenerating unit 300 preferably includes a motor-generator 310, a hydraulic pump-motor 330, and a power storage unit 350, as shown in FIG.

The motor-generator 310 is drivable by a motor or a generator. That is, the motor-generator 310 can implement power generation and transmission. When the motor-generator 310 is driven as a generator, power generation and kinetic energy generation are possible. The motor-generator 310 generates electric energy through power, and the generated electric energy can be stored in the power storage unit 350 described below.

The hydraulic pump-motor 330 is connected to the motor-generator 310 and can be driven by a hydraulic pump or a hydraulic motor. The hydraulic pump-motor 330 may be a constant capacity hydraulic pump-motor 330 through which the oil flows in both directions.

The power storage unit 350 stores electric energy produced when the motor-generator 310 is driven by the generator. The power storage unit 350 may be a battery, a battery, or a capacitor. The power storage unit 350 may store electric energy.

On the other hand, the energy regenerated from the hydraulic driving unit 210 may be kinetic energy due to gravitational potential energy and / or rotary inertia moment.

The position energy due to gravity occurs when the boom is down, and this position energy generates hydraulic energy in the boom cylinder 212 connected to the boom, and the flow rate due to the hydraulic energy flows to the open B port direction switching valve 222 To the B port. At this time, the valve module 250 connected on the circuit connecting both ends of the boom cylinder 212 can operate in the low-pressure side regeneration shrink mode as shown in FIG. The hydraulic pump-motor 330 receives the flow rate through the port B, and operates as a motor. The hydraulic pump-motor 330 receives the rotational force from the hydraulic pump-motor 330 driven by the motor and drives the motor-generator 310 as a generator. The electric energy generated from the generator is stored in the power storage unit 350.

The kinetic energy due to the rotational moment of inertia is generated at the time of turning stop of the upper body. This kinetic energy drives the swing motor 211 connected to the upper body, and the flow rate generated by the swing motor 211 is changed to the A port direction switching valve 221 to the A port. The hydraulic pump-motor 330 receives the flow rate through the port A and drives the hydraulic pump-motor 330 as a motor. The hydraulic pump-motor 330 receives the rotational force from the hydraulic pump-motor 330 driven by the motor and drives the motor- The electric energy generated from the generator is stored in the power storage unit 350.

When the energy regenerated from the hydraulic driving unit 210 is received and stored, the hydraulic pump-motor 330 receives the energy regenerated from the hydraulic driving unit 210 and drives the hydraulic pump-motor 330 as a motor. The motor-generator 310 receives the rotational force from the hydraulic pump-motor 330 and drives the motor-generator 310 as a generator.

The motor-generator 310 receives the electric energy stored in the power storage unit 350 to drive the motor-generator 310 as a motor, and the motor-generator 310, which is driven by the motor, And the hydraulic pump-motor 330 is driven by the hydraulic pump.

The flow rate supplied when the hydraulic pump-motor 330 is driven by the hydraulic pump can be used in three embodiments as follows.

3, the hydraulic pump-motor 330 is driven by a hydraulic pump, and the flow rate can be supplied to each of the hydraulic drive units 210.

That is, the flow rate is supplied through the A port, passes through the A port direction switching valve 221, and is supplied to the swing motor.

Further, the flow rate is supplied through the port B and is supplied to the boom cylinder 212 through the B port direction switching valve 222.

Further, the flow rate is supplied through the C port, passes through the C port direction switching valve 223, and is supplied to the arm cylinder 213.

Further, the flow rate is supplied through the D port, passes through the D port direction switching valve 224, and is supplied to the bucket cylinder 214.

As described above, the flow rate can be supplied to each hydraulic driving unit 210 through the A port, the B port, the C port and the D port. At this time, whether or not the directional control valves 221, 222, 223, The flow rate may be supplied to or disconnected from the hydraulic driving unit 210. FIG.

That is, when all the directional control valves 221, 222, 223, and 224 of the respective ports are opened, they can be supplied to all of the hydraulic driving units 210, and any one of the directional control valves 221, 222, 223, When the switch valve is closed, the supply of the flow rate to the hydraulic pressure drive unit 210 connected to the port is shut off, and the flow rate is supplied only to the open direction switching valve.

Next, as shown in Fig. 4, the hydraulic pump-motor 330 is driven by the hydraulic pump, and the flow rate can be supplied to the main circuit constituting the valve module and the hydraulic drive unit 200. [ At this time, a switching valve 370 may be connected to the hydraulic circuit connected to the main circuit.

When the switching valve 370 is opened as described above, the flow rate supplied to the main circuit is supplied to the first direction switching valve 231 connected to the hydraulic circuit to which the swing motor 211 is connected, The flow rate can be supplied to or cut off from the swing motor 211 depending on whether the switching valve 231 is open or closed.

Further, the flow rate supplied to the main circuit is directly supplied to each valve module 250. That is, a circuit for connecting both ends of the boom cylinder 212, a circuit for connecting both ends of the arm cylinder 213, and a valve module 250 connected to the circuit for connecting both ends of the bucket cylinder 214, . The supplied flow rate can be supplied or blocked to each hydraulic cylinder 212, 213, 214 depending on whether the valve constituting the valve module 250 is opened or closed.

Finally, as shown in Fig. 5, the hydraulic pump-motor 330 is driven by the hydraulic pump, and the flow rate can be supplied to the front side of the main pump 130. [ At this time, a switching valve 380 may be connected to the hydraulic circuit connected to the main pump 130.

When the switching valve 380 is opened, the flow rate is supplied to the front side of the main pump 130, and the flow rate thus supplied is stored in the accumulator 150.

When the user operates the joystick 450 as shown in FIG. 1, the controller 400 controls the operation of the main pump (not shown) 130, the switching valve 170, and the valve module 250. [

According to the energy recovery tandem hydraulic hybrid excavator system using the motor-generator 310 of the present invention, the following effects can be obtained.

An energy recovery unit 300 for receiving and storing the energy recovered from the hydraulic drive unit 210 and supplying the flow rate to the hydraulic drive unit 210 when necessary is mounted, This is possible.

Accordingly, when the required power width is large, the stable and smooth operation of the hydraulic drive unit 210 is enabled through the energy regenerator 300, which operates as an auxiliary accumulator even when the supply of the flow rate is insufficient only by the accumulator 150, Do.

Thus, the engine 110 and the main accumulator 150 can be downsized.

Further, the regenerative energy of the hydraulic driving unit 210 may be stored in an electric form and utilized variously.

Since the valve module 250 of each hydraulic driving unit 210 is constituted by a combination of the independent metering valves, the independent hydraulic driving unit 210 can be driven by one main accumulator 150, Energy recovery can be maximized.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood that various changes and modifications may be made without departing from the scope of the appended claims.

100:
110: engine
130: main pump
150: accumulator
170: Switching valve
200: Valve module and hydraulic drive
210:
211: Swing motor
212: Boom cylinder
213: female cylinder
214: Bucket cylinder
250: Valve module
300: Energy regeneration unit
310: Motor-generator
330: Hydraulic pump-motor
350:

Claims (8)

A hydraulic pressure charging unit for generating and storing a flow rate;
A valve module and a hydraulic drive unit including a hydraulic actuator provided for linear motion or rotary motion, and a valve module for controlling the flow rate stored in the hydraulic pressure chamber and distributing the flow rate to the hydraulic actuator;
And an energy recovery unit that receives and stores energy regenerated from the hydraulic drive unit and supplies the flow rate to the hydraulic drive unit when necessary,
The energy recovery unit may include:
A motor-generator capable of being driven by a motor or a generator,
A hydraulic pump-motor connected to the motor-generator and driven by a hydraulic pump or a motor,
And a power storage unit that stores electric energy produced when the motor-generator is driven as a generator,
When the energy regenerated from the hydraulic driving unit is received and stored,
The hydraulic pump-motor is driven as a motor, and receives the rotational force from the hydraulic pump-motor driven by the motor, the motor-generator is driven as a generator,
When the flow rate is supplied to the hydraulic drive unit when necessary,
The motor-generator receives the electric energy stored in the power storage unit, drives the motor-generator as a motor, receives the rotational force from the motor-generator driven by the motor, drives the hydraulic pump-
Wherein the hydraulic pump-motor is driven by a hydraulic pump to supply a flow rate to a front side of the main pump. delete delete delete The method according to claim 1,
The hydraulic pressure-
An engine,
A main pump for receiving the rotational force of the engine to generate a flow rate,
An accumulator for storing a flow rate generated by the main pump,
And a switching valve for controlling the flow rate storage or use of the accumulator. The energy recovery tandem hydraulic hybrid excavator system using the motor-generator. delete The method according to claim 1,
The hydraulic drive unit includes:
A swing motor for rotating the upper body,
A boom cylinder for operation of the boom,
A female cylinder for operation of the arm,
A bucket cylinder for operation of the bucket,
Wherein the valve module comprises a combination of independent metering valves. ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1,
The energy regenerated from the hydraulic drive unit
Wherein the hydraulic excavator is at least one of kinetic energy due to gravity and kinetic energy due to rotational inertia moment.

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