JP2003329012A - Construction equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide construction equipment which is compact and low in cost without damaging performance of fine speed control and furthermore, which can efficiently collect energy. <P>SOLUTION: The equipment has regenerative hydraulic circuits 45, 46, 47 which are configured to be provided with pump motors 48, 49, 50 rotatably driven by return oil which collects the return oil from metering-out side in hydraulic actuators 10, 11, 12 driving a farm working machinery 6, a selector means which switches off to open or close the hydraulic revival circuits 45, 46, 47, and an electric generator 51 which generates electric power by rotational force from the pump motors 48, 49, 50. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction machine equipped with a system for recovering energy of return oil from a hydraulic actuator.

[0002]

2. Description of the Related Art Conventional construction machines are mainly hydraulically driven. For example, a hydraulic excavator is configured to drive a work machine, revolve an upper revolving structure, and travel a lower traveling structure by a hydraulic actuator (hydraulic cylinder, hydraulic motor). Further, in this hydraulic excavator, excavation work and the like are performed by controlling the supply of pressure oil from a hydraulic pump whose drive source is an engine to a hydraulic actuator. In such a hydraulic construction machine, there are problems such as energy loss, difficulty in complex operations and fine speed control in work machines, and responsiveness. It is known that the problems of combined operation, fine speed control and responsiveness can be solved by a combination of a hydraulic system including a pressure compensation valve and an electronic control system.

As a solution to the above-mentioned problem of energy loss, for example, Japanese Patent Application No. 2001, which is a prior application of the present applicant.
There is a hybrid hydraulic excavator proposed in No. 068656. This hybrid hydraulic excavator is configured so that pressure oil discharged from a variable displacement hydraulic pump driven by an engine is supplied to a hydraulic actuator (boom cylinder, arm cylinder, bucket cylinder, etc.) via a control valve. As well as
An electric motor driven by an engine and having a power generation function;
A battery for charging the electric power generated by the electric motor is provided, and the surplus energy of the engine is stored in the battery, and the electric motor applies a rotational torque to the hydraulic pump as needed. In addition, this hybrid hydraulic excavator is provided with a generator that is connected to a hydraulic motor that rotates with return oil from the bottom side of the boom cylinder. It is designed to store electricity.

As another aspect that can solve the problems of difficulty and responsiveness of complex operations and fine speed control in the working machine described above, there is an electric excavator disclosed in, for example, Japanese Patent Laid-Open No. 2001-226077. . This electric excavator is equipped with an AC electric motor for a working machine that drives each actuator that operates a boom, an arm, and a bucket, and an inverter that converts the output of a power supply into a high-frequency AC output through a converter. In addition to being configured to be controlled by the inverter, the controller is configured to control the outputs of the inverter and the converter according to the output signal of the operation lever. In this electric excavator, the AC electric motor for the working machine is drive-controlled by the setting operation signal of the operation lever to operate the boom, arm, and bucket.

[0005]

However, in the hybrid type hydraulic excavator, since the return oil from the bottom side of the boom cylinder is configured to always flow through the hydraulic motor, there is a delay in response at the time of starting the hydraulic motor. Therefore, there is a problem that responsiveness and fine speed control performance (fine control performance) are deteriorated during the adjustment work and the fine operation work. Further, there is a problem that the energy of the return oil generated in the hydraulic actuator other than the boom cylinder, that is, the arm cylinder or the bucket cylinder cannot be recovered. In this case, it is conceivable that the return oil from the arm cylinder and the bucket cylinder is circulated to the hydraulic motor through which the return oil from the boom cylinder circulates for energy regeneration. Therefore, the response delay at the time of start-up becomes longer, and the responsiveness and fine control performance during the adjustment work and the fine operation work may be further impaired. Further, since the pressure of the return pressure oil is different for each cylinder, the energy of the return pressure oil may not be efficiently recovered due to the influence of the backflow.

Further, since an electric motor generally has a smaller output torque per unit weight than a hydraulic actuator,
In the electric excavator, it is necessary to increase the capacity of the electric motor for driving the boom, the arm, and the bucket, which causes problems in arrangement and increases costs. In addition, there is a problem that it is difficult to ensure safety when the power source is down.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a construction machine which is compact and low-cost, which can efficiently recover energy without impairing fine control performance. It is intended.

[0008]

In order to achieve the above-mentioned object, the construction machine according to the first aspect of the present invention is a construction machine equipped with a hydraulic actuator, wherein return oil from the meter-out side of the hydraulic actuator is used. A hydraulic regenerative circuit configured to include a rotary machine that is recovered and rotationally driven by the recovered return oil, switching means that switches between opening and closing of the hydraulic regenerative circuit, and power generation that generates electric power by the rotational force from the rotary machine. A machine is provided.

According to the present invention, when the return oil from the meter-out side of the hydraulic actuator is collected and the hydraulic regeneration circuit is opened by the switching operation of the switching means, the return oil drives the rotary machine to rotate. As a result, electric power is generated from the generator. Therefore, the hydraulic energy of the return oil from the meter-out side of the hydraulic actuator can be recovered as electric energy. Therefore, it is possible to drive the working machine and recover energy in a compact size and at low cost without using a large-capacity electric motor as in the conventional technique. Further, when the work requiring the responsiveness is performed, if the hydraulic regeneration circuit is closed by the switching operation of the switching means, the fine control performance (fine speed control performance) is deteriorated due to the response delay at the start of the rotating machine. Has the advantage that it can be prevented.

Next, the construction machine according to the second aspect of the present invention is a construction machine having a plurality of hydraulic actuators, for each hydraulic actuator, return oil from the meter-out side of the hydraulic actuator is recovered, and the recovered return oil is recovered. And a switching means for switching between opening and closing of the hydraulic regeneration circuit, and a generator for generating electric power by the rotational force from the rotating machine. It is characterized by being.

According to the present invention, it is possible to obtain basically the same effect as that of the first invention, and since a hydraulic regeneration circuit is provided for each hydraulic actuator, a plurality of construction machines can be used. Even with a configuration equipped with hydraulic actuators, the return oils from the meter-out side in those hydraulic actuators do not interfere with each other,
The hydraulic energy of each return oil can be reliably recovered as electric energy.

In the first invention or the second invention, it is preferable that the switching means has a controller, and the controller controls the switching operation of the switching means according to working conditions (third invention). In this way, for example, when the present invention is applied to a shovel-type construction machine, the hydraulic regenerative circuit is opened when performing heavy excavation work or normal excavation work, and adjustment work or fine operation work is performed. When performing work requiring controllability, it is possible to easily control the switching means so as to close the hydraulic regeneration circuit, so that it is possible to efficiently recover the return oil energy while maintaining fine control performance. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, concrete embodiments of the construction machine according to the present invention will be described with reference to the drawings.
The present embodiment is an example in which the present invention is applied to a hybrid hydraulic excavator which is a type of construction machine.

FIG. 1 is a side view of a hybrid hydraulic excavator according to an embodiment of the present invention. Further, FIG. 2 shows a schematic configuration diagram of the hybrid system and the energy recovery system in the present embodiment.

As shown in FIG. 1, a hybrid hydraulic excavator 1 according to this embodiment has a lower traveling body 2, an upper revolving body 4 provided on the lower traveling body 2 through a revolving mechanism 3, and a lower revolving body 4. The work machine 6 attached to the upper swing body 4 is provided. The working machine 6 is configured by sequentially connecting a boom 7, an arm 8 and a bucket 9 from the upper swing body 4 side, and the boom 7, the arm 8 and the bucket 9 are respectively connected to the boom cylinder 10 and the arm 9. The cylinder 11 and the bucket cylinder 12 are rotatably driven by expansion and contraction operations. Further, the upper swing body 4 is provided with a driver's cab 5, and an operating device (not shown) for operating a boom, an arm, a bucket and the like is mounted inside the driver's cab 5.

As shown in FIG. 2, the hybrid hydraulic excavator 1 includes an engine 21, a variable displacement hydraulic pump 22, a control valve 23 for controlling the flow of hydraulic oil, the control valve 23, and a control valve 23 described later. A controller 24 that controls the operation of various devices is provided. In this hybrid hydraulic excavator 1, pressure oil discharged from a hydraulic pump 22 driven by an engine 21 is hydraulically actuated via a control valve 23, that is, a boom cylinder 10, an arm cylinder 1
First, it is supplied to the bucket cylinder 12.

The engine 21 is provided with a governor 21a for adjusting its rotational speed according to the increase or decrease of the load, and the governor 21a is provided with a controller 24 during operation.
A governor command signal for rated rotation is input from. In this way, the engine 21 is driven to rotate at constant torque and constant rotation at the rated output point.

Further, the engine 21 is equipped with an electric motor 25 integrated with a flywheel (not shown). The electric motor 25 is an induction motor having a flywheel as a rotor and a stator provided around it. The electric motor 25 also has a function as a generator, and operates the motor for assisting the hydraulic pump drive of the engine 21 and the engine 21. It is configured to be able to switch between a power generation operation for generating power as a drive source.
This electric motor 25 is connected to the battery 2 via an inverter 26.
7, the inverter 26 controls the power generation operation and the motor operation of the electric motor 25 in response to a command from the controller 24. As the battery 29, a secondary battery such as a lithium ion battery is used.

The upper revolving structure 4 is rotatable by an electric motor 29 connected via a speed reducer 28. Like the electric motor 25, the electric motor 29 also has a function as a generator, and operates a motor for driving the upper swing body 4 and a power generation operation by inertia energy (rotation energy) of the upper swing body 4 during swing braking. It is an induction motor configured to be switchable between and. The electric motor 29 is connected to the battery 27 via an inverter 26, and the inverter 26 controls the power generation operation and the motor operation of the electric motor 29 according to a command from the controller 24.

A pump motor (corresponding to the rotating machine of the present invention) 48 is provided in the bottom pipe 31 of the boom cylinder 10.
An oil pressure regeneration circuit 45 is provided so as to branch from the conduit 31 via the switching valve 32. Here, in the switching valve 32, control pressure oil from a control pressure source 34 supplied via an electromagnetic switching valve 33 that is switched according to a command from the controller 24 is used as the switching valve 32.
The switching operation is performed by being supplied to the operation unit (corresponding to the switching means in the present invention). Then, when the switching valve 32 is set to the (a) position as shown in FIG. 2 (a state in which the hydraulic regeneration circuit 45 is closed) corresponding to a work mode described later, the boom cylinder 10 is moved from the bottom chamber. The return oil is returned to the tank 20 via the pipe 31 and the control valve 23. On the other hand, when the electromagnetic switching valve 33 is switched from the position (a) to the position (b) by a predetermined electric signal according to a command from the controller 24 in accordance with a work mode described later, control from the control pressure source 34 is performed. The pressure oil is supplied to the operation portion of the switching valve 32, and the switching valve 32 (a)
The position is switched to the position (b) (hydraulic regeneration circuit 4
5 is open). As a result, the boom cylinder 10
The return oil from the bottom chamber is returned to the tank 20 via the hydraulic regeneration circuit 45.

A hydraulic regeneration circuit 46 having a pump motor (corresponding to the rotating machine of the present invention) 49 is also provided in the head-side conduit 35 of the arm cylinder 11, and the switching valve 3 is provided.
It is provided so as to branch from the conduit 35 via 6. Here, in the switching valve 36, the control pressure oil from the control pressure source 34 supplied via the electromagnetic switching valve 37 that is switched according to the command of the controller 24 is operated by the operating portion of the switching valve 36. The switching operation is performed by being supplied to (corresponding to the switching means in the present invention). And
When the switching valve 36 is set to the (a) position as shown in FIG. 2 corresponding to the work mode described later (the hydraulic regeneration circuit 46
(In the closed state), the return oil from the head chamber of the arm cylinder 11 passes through the conduit 35 and the control valve 23.
Is recirculated to the tank 20 via. On the other hand, the electromagnetic switching valve 37 corresponds to the controller 2 in accordance with a work mode described later.
When the position (a) is switched to the position (b) by a predetermined electric signal according to the command from the control pressure source 4, the control pressure oil from the control pressure source 34 is supplied to the operation portion of the switching valve 36, and the switching valve 36.
Is switched from the position (a) to the position (b) (the hydraulic regeneration circuit 46 is opened). As a result, the return oil from the head chamber of the arm cylinder 11 will not be returned to the hydraulic regeneration circuit 46.
Is recirculated to the tank 20 via.

Further, in the pipe line 38 on the bottom side and the pipe line 41 on the head side in the bucket cylinder 12,
A hydraulic regeneration circuit 47 including a pump motor (corresponding to the rotating machine of the present invention) 50 is provided between the switching valve 39 and the switching valve 42.
It is provided so as to branch from the conduit 38 and the conduit 41 via the. Here, the switching valve 39 and the switching valve 42 are switched and operated in response to a command from the controller 24.
The control pressure oil from the control pressure source 34 supplied via 3 is supplied to the operation portions of the switching valve 39 and the switching valve 42 to perform switching operation (corresponding to switching means in the present invention. ). Then, when the switching valve 39 and the switching valve 42 are set to the positions (a) as shown in FIG. 2 (a state where the hydraulic regeneration circuit 47 is closed) corresponding to a work mode described later, the bucket cylinder 12 The return oil from the bottom chamber is returned to the tank 20 via the pipe 38 and the control valve 23, and the return oil from the head chamber is returned to the tank 20 via the pipe 41 and the control valve 23. On the other hand, the electromagnetic switching valve 40
Is switched from the position (a) to the position (b) by a predetermined electric signal according to a command from the controller 24, control pressure oil from the control pressure source 34 is supplied to the operation portion of the switching valve 39, and the switching valve 39 is switched from the position (a) to the position (b) (the state in which the hydraulic regeneration circuit 47 is opened). As a result, the return oil from the bottom chamber of the bucket cylinder 12 is returned to the tank 20 via the hydraulic regeneration circuit 47. Similarly, when the electromagnetic switching valve 43 is switched from the (a) position to the (b) position, the switching valve 42 is switched from the (a) position to the (b) position (the hydraulic regeneration circuit 47 is opened). The return oil from the head chamber is also returned to the tank 20 via the hydraulic regeneration circuit 47.

The return oil from the boom cylinder 10, arm cylinder 11 and bucket cylinder 12 is
When the oil is returned to the tank 20 through the hydraulic regeneration circuit 45, the hydraulic regeneration circuit 46, and the hydraulic regeneration circuit 47, respectively, as described above, the return oils drive the pump motor 48, the pump motor 49, and the pump motor 50, respectively. It is supposed to be done. Here, the output shafts of the pump motors 48, 49, 50 are directly connected, and
A generator 51 is provided which is driven by the rotational force from the directly connected output shaft. In addition, this generator 51
Are connected to the battery 27 via a converter (AC / DC converter) 52. The pump motors 48, 49, 50 are variable displacement pump motors, and the tilt angles of the swash plates of the pump motors 48, 49, 50 are tilted according to a command from the controller 24. It is adapted to be controlled by the plate driving means 48a, 49a, 50a. In this embodiment, by controlling the tilt angle of the swash plate, the rotation speeds of the pump motors 48, 49, 50 are adjusted, and the pump motors 48, 49, 50 are rotated in synchronization with each other. ing.

In this embodiment, a boom operating lever 61, an arm operating lever 62, and a bucket operating lever 63 provided on an operating device (not shown) in the operator's cab 5.
A detection signal from an operation amount detector (for example, a potentiometer) provided in each of the above is input to the controller 24, and the controller 24 controls the operation of the control valve 23 based on the input signal, The flow rate of the pressure oil supplied to the corresponding hydraulic actuator is controlled. Further, a detection signal from an operation amount detector provided on the turning operation lever 64 is also input to the controller 24, and the controller 24 causes the inverter 26 to operate based on the input signal.
The motor operation of the electric motor 29 is controlled via the.

Although not shown in detail, the controller 24 includes a rotation sensor for detecting the rotation speed of the engine 21, a torque sensor for detecting the output torque of the engine 21, and a swash plate for detecting the swash plate angle of the hydraulic pump 22. Corner sensor,
Detection signals from a pressure sensor that detects the discharge pressure of the hydraulic pump 22 and a swash plate angle sensor that detects the swash plate angles of the pump motors 48, 49, 50 are input.

A monitor panel 65 is connected to the controller 24. The monitor panel 65 is a selection signal of a work mode (heavy excavation mode, normal excavation mode, adjustment mode, fine operation mode, etc.) corresponding to each work condition such as heavy excavation work, normal excavation work, adjustment work, and slow speed work. Based on the work mode selected on the monitor panel 65, the controller 24 adjusts to the optimum engine torque and pump output according to the work content. . Further, the controller 24 controls the opening / closing of the hydraulic pressure regenerative circuits 45, 46, 47 in accordance with the work mode selected on the monitor panel 65. In this embodiment, when the heavy excavation mode or the normal excavation mode is selected,
The hydraulic pressure regeneration circuits 45, 46, 47 are opened, and the hydraulic pressure regeneration circuits 45, 4 to which the respective return oils from the boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12 correspond.
When the energy regeneration is carried out by being guided to 6, 6 and 47 and the adjustment mode or the fine operation mode is selected, the hydraulic regeneration circuits 45, 46 and 47 are closed and the boom cylinder 1
0, the arm cylinder 11, and the return oil from the bucket cylinder 12 pass through the control valve 23 to the tank 20.
It is supposed to be returned to.

When the boom operating lever 61, the arm operating lever 62 and the bucket operating lever 63 are set to neutral,
The controller 24 controls the engine 21 via the governor 21a.
The work load pressure from the pressure compensating valve (not shown) and the outlet pressure of the hydraulic pump 22 actuate the swash plate driving means (not shown) of the hydraulic pump 22 to reduce the rotational speed of the hydraulic pump 22. The swash plate angle is changed (so-called pump / valve control) to reduce the amount of oil discharged from the hydraulic pump 22 and improve the fuel efficiency.

The operation of the hybrid hydraulic excavator of the present embodiment thus constructed will be described with reference to FIG.

The work load is small, and the absorption torque of the hydraulic pump 22 (the torque required by the hydraulic pump 22 to drive the hydraulic actuator) is set to the engine 2.
If the output torque is less than 1, the controller 24
Causes the electric motor 25 to generate electric power by the surplus torque. That is, the controller 24 calculates a surplus torque by comparing the pump absorption torque obtained from the discharge pressure of the pump 22 and the swash plate angle with the rated torque, and the calculated surplus torque acts on the electric motor 25 as a power generation torque. Thus, the inverter 26 controls the current flowing through the electric motor 25. Then, the electric energy generated by this surplus torque is stored in the battery 27. In this way, a part of the output of the engine 21 is absorbed by the hydraulic pump 22 and consumed for driving the working machine, and the rest is absorbed by the electric motor 25 that operates to generate electric power and stored in the battery 27 as electric energy.

When the work load is large and the absorption torque of the hydraulic pump 22 is larger than the output torque of the engine 21, the controller 24 operates the electric motor 25 to generate the insufficient torque, and the engine 21 is hydraulically operated. Helps drive pump 22. That is, the controller 24 calculates the insufficient torque by comparing the pump absorption torque and the rated torque, and the inverter 26 supplies the current supplied from the battery 27 to the electric motor 25 so that the electric motor 25 outputs the calculated insufficient torque. Control with.

During the turning operation, the turning operation lever 6
Based on the operation signal input from the operation amount detector to the controller 24 according to the operation amount of 4, the controller 24 controls the motor operation of the electric motor 29 via the inverter 26, whereby the upper swing body 4 performs the swing operation. Lever 64
Is swung at a speed according to the operation amount of. On the other hand, at the time of swing braking, the controller 24 switches the electric motor 29 to the power generation operation so as to generate the torque in the direction for braking the swing motion of the upper swing body 4, and changes the inertia energy (rotation energy) of the upper swing body 4 into electric energy. Convert to battery 2
The energy stored in 7 is regenerated.

As described above, in this embodiment, the hydraulic regeneration circuit 4 is selected according to the mode selected on the monitor panel 65.
Opening and closing of 5, 46 and 47 can be switched. Hereinafter, the case of selecting the heavy excavation mode or the normal excavation mode and the case of selecting the adjustment mode or the fine operation mode will be described in order.

When the heavy excavation mode or the normal excavation mode is selected, each hydraulic regeneration circuit 45, 46, 47 is opened. Therefore, (1) When the boom lowering operation is performed in the boom cylinder 10, that is, the boom cylinder 10 is contracted, the high pressure return oil from the bottom side is guided to the hydraulic regeneration circuit 45, and the pump motor 48 is driven by the return oil. To be done. As a result, the generator 51 is driven to generate electricity,
The generated power is converted to DC power by the converter 52,
It is supplied to the battery 27 and stored. (2) When the arm cylinder 11 is extended, the high-pressure return oil from the head side is guided to the hydraulic regeneration circuit 46, and the pump motor 49 is driven by the return oil. As a result, the generator 51 is driven to generate power, and the generated power is stored in the battery 27. (3) When the bucket cylinder 12 is extended or contracted,
High-pressure return oil from the head side or the bottom side is guided to the hydraulic pressure regeneration circuit 47, and the pump motor 50 is driven by the return oil. As a result, the generator 51 is driven to generate power, and the generated power is stored in the battery 27.

When the adjustment mode or the fine operation mode is selected, the hydraulic pressure regeneration circuits 45, 46 and 47 are closed. Therefore, the high pressure return oil from the bottom side during the contraction operation of the boom cylinder 10 passes through the pipe line 31, and the high pressure return oil from the head side during the extension operation of the arm cylinder 11 passes through the pipe line 35. The high-pressure return oil from the head side or the bottom side during the extension operation or the contraction operation of the bucket cylinder 12 is supplied to the pipeline 4
Any return oil is returned to the tank 20 via the control valve 23 through the control valve 23.

According to this embodiment, the working machine 6 can be operated by the boom cylinder 10, the arm cylinder 11 and the bucket cylinder 12 as in the conventional hydraulic excavator, and the hydraulic pressure of the return oil from each cylinder can be increased. Energy can be recovered as electrical energy. Therefore, it is possible to drive the working machine and recover energy at a compact size and at low cost without using a large-capacity electric motor as in the prior art, and to ensure safety even when the power is down. it can. Further, for the boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12, the hydraulic pressure regeneration circuit 4 is provided, respectively.
5. Since the hydraulic regeneration circuit 46 and the hydraulic regeneration circuit 47 are provided, the hydraulic energy of each return oil can be reliably recovered as electric energy without interfering the return oils from the hydraulic actuators with each other. .

The controller 24 controls the hydraulic regeneration circuit 4 according to the work mode selected on the monitor panel 65.
The opening / closing of 5, 46, 47 is controlled to be switched, that is, when the heavy excavation mode or the normal excavation mode is selected, the hydraulic regeneration circuits 45, 46, 47 are opened,
When the adjustment mode or the fine operation mode is selected, the hydraulic pressure regeneration circuits 45, 46, 47 are closed, so that the fine control performance is deteriorated due to the delay in response at the time of starting the pump motors 48, 49, 50. The energy of the return oil from each cylinder can be efficiently recovered while preventing it, that is, ensuring the fine control performance.

In this embodiment, the switching of the opening and closing of the hydraulic regeneration circuits 45, 46, 47 is performed by the monitor panel 6.
Although an example of interlocking with the work mode selection switch in 5 has been shown, the invention is not limited to this, and the monitor panel 65 is provided with an opening / closing changeover switch for the hydraulic pressure regeneration circuits 45, 46, 47 exclusively.
With this open / close switch, the hydraulic regeneration circuits 45, 4
The opening and closing of 6, 47 may be switched.

[Brief description of drawings]

FIG. 1 is a side view of a hybrid hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a hybrid system and an energy recovery system according to the present embodiment.

[Explanation of symbols]

1 hybrid hydraulic excavator 6 working machine 7 boom 8 arms 9 buckets 10 boom cylinder 11 arm cylinder 12 bucket cylinders 24 controller 32, 36, 39, 42 switching valve 33, 37, 40, 43 Electromagnetic switching valve 45,46,47 Hydraulic regeneration circuit 48,49,50 pump motor 51 generator

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F15B 11/17 F15B 11/00 F H02P 9/04 11/16 A F term (reference) 2D003 AA01 AB03 AC06 BA01 BA05 CA02 CA10 DA02 DB01 DB02 DB03 DB04 DB05 3H089 AA23 AA60 BB04 BB14 CC01 CC09 CC11 DA03 DA07 DA13 DA14 DA15 DB45 DB48 EE16 EE22 EE36 FF05 FF14 GG02 JJ02 5H590 AA02 CA23 CA30 CC01 CD01 CD03 CE08 CE13 CE04 CE13 CE04 CE13

Claims (3)

[Claims] 1. A construction machine provided with a hydraulic actuator, comprising: a hydraulic regeneration circuit comprising a rotary machine that collects return oil from the meter-out side of the hydraulic actuator and is driven to rotate by the collected return oil. , Switching means for switching the opening and closing of the hydraulic regeneration circuit,
A construction machine comprising a generator that generates electric power by the rotational force from the rotating machine. 2. A construction machine provided with a plurality of hydraulic actuators, comprising: for each of the hydraulic actuators, a rotary machine that collects return oil from the meter-out side of the hydraulic actuator and is driven to rotate by the collected return oil. A construction machine characterized in that a hydraulic regeneration circuit configured as described above and switching means for switching between opening and closing of the hydraulic regeneration circuit are provided, and a generator that generates electric power by the rotational force from the rotating machine is provided. 3. The construction machine according to claim 1, wherein the switching means has a controller, and the controller controls the switching operation of the switching means according to working conditions.