JP2001012274A - Driving gear for work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize an engine speed to attain improvement of convenience for use, by connecting a generator concurrently an electric motor to an engine driving an oil hydraulic pump, and promoting saving of energy while small size capacity of the engine is attained. SOLUTION: This driving gear for a work machine comprises an engine, oil hydraulic pump, generator and electric motor, battery, first controller charging the battery with power generated by the generator and electric motor to drive the generator and electric motor by using power of the battery, and a controller. When an oil hydraulic pump input is smaller than an engine output, the engine is operated between a prescribed preset rotational speed and a high idle rotational speed. When the oil hydraulic pump input is larger than the engine output, the oil hydraulic pump input is decreased, the generator and electric motor is operated as the electric motor, to compensate the engine output, and the engine is operated at a preset rotational speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a working machine such as a shovel or a crane using an engine such as a diesel engine as a power source, and more particularly, to a generator / motor connected to one end of an engine output. The present invention relates to a drive device for a working machine that assists engine output with a battery and a battery.

[0002]

2. Description of the Related Art Conventionally, working machines such as shovels and cranes are generally equipped with an engine such as a diesel engine in order to obtain power for self-propelled operation. By supplying hydraulic oil discharged from a hydraulic pump to a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder, rotation of a traveling crawler or a tire, and operation of each work site such as a boom, an arm, and a bucket are performed. .

FIG. 6 is an overall structural view of a self-propelled shovel, FIG. 7 is a graph showing a relationship between a discharge pressure and a discharge flow rate of a hydraulic pump, and FIG. 8 shows an engine speed and output / torque. It is a graph.

In FIG. 6, the self-propelled shovel includes a traveling crawler 52 having left and right traveling drive hydraulic motors 51. On the traveling crawler 52, an upper revolving body 53 is installed so as to be able to pivot around a vertical axis. Have been. Upper revolving structure 53
Is provided with a driver seat 54 and the engine 5
5, hydraulic pump 56, hydraulic oil tank 57, fuel tank 58, turning drive hydraulic motor 59, turning drive reducer 6
0 etc. are mounted. A boom 61 and an arm 6 are provided at the front portion of the upper swing body 53 as working members for performing work.
2. A bucket 63 is provided and connected to be operated by a boom cylinder 64, an arm cylinder 65, and a bucket cylinder 66, respectively. A hydraulic motor for traveling drive 51, a hydraulic motor for turning drive 59, a boom for operating each work member by using a hydraulic oil discharged from the hydraulic pump 56 to rotate a hydraulic pump 56 using an output of an engine 55 as a power source, a boom The cylinder 64, the arm cylinder 65, and the bucket cylinder 66 are driven.

[0005] As the hydraulic pump 56, for example, a variable discharge pump is used. The output (= discharge pressure) is determined by the relationship between discharge pressure and discharge flow so that the output does not exceed the rated output of the engine.
(Discharge pressure × discharge flow rate) It is set to have a constant characteristic and to have a value near the engine rated output. As a result, while preventing the absorption horsepower of the hydraulic pump from exceeding the rated output of the engine and causing engine stall (stall),
The aim is to maximize the output of the engine.

As shown in FIG. 7, the constant output characteristic of the variable discharge pump is represented by a hyperbolic curve in a discharge pressure-discharge flow plane, and the vicinity of the rated output is used so as to make maximum use of the engine rated output (A). Is set to the pump input (B).

As shown in FIG. 8, the engine 55 has a torque rise characteristic below the rated speed, and has a characteristic that both the torque and the output decrease in the range from the rated speed to the high idle speed.

In order to use the engine output efficiently,
The engine 55 is maximum (rated) when the input of the hydraulic pump 56 is maximum, and is operated near the rated speed. Then, when the hydraulic pump input decreases, the engine output also decreases, and the engine speed moves toward the high idle speed and the engine is operated at a speed higher than the rated speed. The high idle speed is a value about 10% higher than the rated speed.

In a transient state in which the input of the hydraulic pump 56 becomes larger than the output of the engine 55 due to a temporary delay in control of the variable discharge pump, the engine speed drops below the rated speed. The engine output torque increases due to the torque rise characteristic of the engine, thereby preventing engine stall. Thus, in the steady state except the transient state, the engine is operated between the rated speed and the high idle speed.

As described above, the reason why hydraulic power is used as a driving device is that, compared with electric power, 1)
Since the driving equipment is lightweight and compact, it is convenient to mount it on a working machine and move on its own. 2) There are advantages such as easy obtaining a large reciprocating thrust using a hydraulic cylinder. And so on. However, hydraulic power has a problem in that energy efficiency for work is lower than electric power. In the hydraulic circuit, by controlling the direction, pressure and flow rate of the hydraulic oil discharged from the hydraulic pump using a control valve,
The operating direction, operating force and operating speed of the hydraulic actuator are controlled. At this time, the rate at which hydraulic energy is throttled and discarded by the control valve to control the pressure and flow rate of the hydraulic oil is large, and when energy supplied from the power source is used for work compared to control using electric power. Large energy loss.

The energy required for the work performed by the working machine varies with time depending on the content of the work to be performed.
The engine as the power source needs to have a capacity capable of supplying the maximum input energy required by the hydraulic pump, and there is also a problem that the utilization efficiency of the engine power is low.

Therefore, in recent years, the following techniques have been proposed from the viewpoint of energy saving in order to overcome the low efficiency of using the engine power and the low efficiency of using the hydraulic power, as described above.

First, an induction machine is attached to a power line of an engine, and a battery for storing electric energy regenerated by the induction machine, and the electric energy stored in the battery is converted into AC power and supplied to the induction machine. An inverter circuit that converts AC power regenerated by the induction machine into DC power and supplies the DC power to the battery;
An internal combustion machine for a hydraulic shovel (actually disclosed in Japanese Unexamined Utility Model Publication No.
No. 501) has been proposed.

This is because when the work performed by the work machine is a light load work with ample engine output, the induction machine is operated as a regenerative generator to charge the battery via the inverter circuit, and an output larger than the engine output is required. At the time of a heavy load operation, the engine is assisted by operating the induction machine as an electric motor via the inverter circuit using the stored power of the battery.

As a result, it is possible to cope with all operations using an engine having a capacity smaller than the maximum working energy required by the hydraulic pump ((C) engine rated output in FIG. 7). To make effective use of engine power.

Next, a swing hydraulic pump motor for swinging the swing system, an accumulator for driving the swing hydraulic pump motor, and a swing controller for switching and controlling the operation of the swing hydraulic pump motor are provided. During braking, the hydraulic pump motor for rotation is operated to pump to regenerate rotational kinetic energy. In addition, an electric motor also serving as a generator is attached to the rotary pump motor. Switching between operation and operation (Japanese Patent Laid-Open No. 10-103112) has also been proposed.

This saves energy by storing the rotational kinetic energy during braking of the turning system and reusing it during turning to save energy and improve the energy efficiency of the hydraulic circuit.

[0018]

In the first prior art, which uses an engine equipped with an induction machine as a driving device, the operation of the induction machine is defined as a power generation operation in accordance with a change in work load. Since the operation is switched between the driving operations, when the work load becomes larger than the engine output and the induction machine is switched to the driving operation, the engine speed is significantly reduced, for example, from 2000 rpm to 1400 rpm, which is the hydraulic circuit. There is a problem in that it appears as a speed fluctuation in driving, and the usability becomes poor when operating the work machine.

Further, in the case of the driving device of the second prior art, in which the turning system is driven by the turning hydraulic pump motor, the regenerated hydraulic energy can be used only for the turning drive of the turning system. there were.

The present invention has been made in view of the above circumstances, and has as its object to provide a drive device for a working machine with improved usability while improving energy use efficiency.

[0021]

According to the present invention, there is provided an engine, a hydraulic pump connected to the engine and having a maximum input greater than an output of the engine, and an output shaft of the engine. A generator / motor connected to and performing a generator operation or a motor operation, a battery for storing power generated by the generator / motor, and a generator / motor connected to the generator / motor and the battery. The operation is switched, and in the case of the generator operation, the power generated by the rotation of the generator / motor is charged in the battery, and in the case of the motor operation, the power stored in the battery is stored in the generator. A driving device for a working machine, comprising: a first controller for supplying the electric motor to the electric motor and rotating the motor; and a controller connected to the first controller. When the input of the hydraulic pump is smaller than the engine output, the controller operates the engine between a predetermined set rotation speed and a high idle rotation speed, and when the input of the hydraulic pump is larger than the engine output, , While reducing the input of the hydraulic pump,
Using the electric power stored in the battery, the generator / motor is operated as an electric motor to supplement the engine output, and the engine is operated near a set rotation speed.

According to this configuration, even when the input of the hydraulic pump becomes larger than the output of the engine, the engine speed is stabilized and the engine is operated at the predetermined set speed. There is no influence and the usability of the work machine is not deteriorated.

The present invention also provides an engine, a hydraulic pump connected to the engine and having a maximum input greater than the output of the engine, and a generator connected to an output shaft of the engine to perform a generator operation or a motor operation. Electric motor,
A battery for storing electric power generated by the generator / motor; and a switch connected to the generator / motor and the battery for switching the operation of the generator / motor. A second controller for charging the battery with the electric power generated by the rotation of the electric motor and supplying the electric power stored in the battery to the electric generator and the electric motor to rotate the electric motor in the case of the electric motor operation; A turning motor / generator for turning the revolving body to perform a motor operation or a generator operation, and switching the operation of the turning motor / generator connected to the turning motor / generator and the battery, When turning the body, the turning electric motor / generator is operated by the electric motor, and the electric power stored in the battery is used to drive the turning electric motor / generator to control the turning body. When is obtained and a third controller for charging the electric power generated by the turning electric motor and the generator the generator is operated the turning electric motor and a generator to the battery.

According to this structure, the battery can be charged by performing the regenerative braking by operating the turning motor / generator as the generator during braking of the revolving body, so that the energy can be stored without increasing the oil temperature of the hydraulic circuit. It can be reused, and can be reused for purposes other than the turning drive.

According to the present invention, in the driving device for the second working machine, the controller further includes a controller connected to the second controller and the third controller, wherein the controller is configured to control an input of the hydraulic pump. When the engine output is smaller than the engine output, the engine is operated between a predetermined set speed and a high idle speed, and when the input of the hydraulic pump is larger than the engine output, the input of the hydraulic pump is reduced. In addition, the generator / motor is operated as a motor using the electric power stored in the battery to supplement the engine output, and the engine is operated near a set rotation speed.

According to this configuration, even when the input of the hydraulic pump becomes larger than the output of the engine, the engine speed is stabilized and the engine is operated at the predetermined set speed. The battery can be charged by performing regenerative braking without affecting the usability of the work machine without affecting it, and by operating the rotating electric motor and generator at the time of braking of the revolving structure, so that the battery can be charged. Energy can be reused.

According to the present invention, in the drive device for a working machine according to any one of the first to third aspects, the engine and the generator / motor are connected via a speed increasing device. is there.

According to this configuration, since the generator / motor can be operated at a higher rotation speed, the generator / motor can be made compact and the installation space can be reduced.

[0029]

Preferred embodiments of the present invention will be described below with reference to the drawings. In the following embodiment, an example in which the present invention is applied to a drive device of a self-propelled shovel including working members such as a boom, an arm, and a bucket will be described. However, the present invention uses an engine as a power source. The present invention can be widely applied to a driving device of a working machine having a working member.

1) First Embodiment (FIGS. 1 to 3) FIG. 1 is a power transmission system diagram showing a first embodiment, and FIG. 2 is a block diagram showing the first embodiment. FIG. 3 is a flowchart showing the first embodiment.

In the power transmission system diagram of FIG. 1, a hydraulic pump 2 is connected to an output of an engine 1 which is a power source, and is a hydraulic actuator via a hydraulic control valve 7 by hydraulic oil discharged from the hydraulic pump 2. The turning drive hydraulic motor 8, the boom cylinder 9, the arm cylinder 10, the bucket cylinder 11, the right running drive hydraulic motor 12, and the left running drive hydraulic motor 13 are driven.

The output of the engine 1 is connected to a generator / motor 4 via a speed increasing mechanism 3. The speed increasing mechanism 3 is, for example, a spur gear type speed increaser, and an input shaft is connected to an engine output shaft, and a gear provided on the input shaft and a gear provided on the output shaft are meshed with each other by, for example, the number of teeth. The speed is increased three times and the rotation of the input shaft is transmitted to the output shaft. The generator / motor 4 is further connected to a first controller 5,
Controller 5 is connected to battery 6.

The generator / motor 4 is, for example, a three-phase AC induction machine that performs a generator operation or a motor operation, and its operation can be switched by the first controller 5. When the generator / motor 4 operates as a generator, the generated AC power is converted into DC by the first controller 5 and charged into the battery 6 connected to the first controller 5. When the generator / motor 4 performs the motor operation, the battery 6
Is converted into AC power by the first controller 5, whereby the generator / motor 4 is rotationally driven.

In this case, the torque of the generator / motor 4 is decelerated at this time via the speed increasing mechanism 3 and transmitted to the output shaft of the engine 1 to assist the output of the engine 1.

In the above operation, even when the generator / motor 4 is a DC motor, the battery 6 is charged via the first controller 5 by the power generation of the generator / motor 4, and the battery 6 is charged. 6 using the electric power stored in the first controller 5
, The rotation of the generator / motor 4 is performed.

When the generator / motor 4 is a three-phase AC induction machine, the first controller 5 converts the AC power generated by the induction machine into DC power and charges the battery. It includes a circuit and an inverter circuit that converts DC power stored in the battery into AC power and rotationally drives the induction machine.

In the block diagram of FIG. 2, a shovel operating mechanism 14 for operating a working member of the shovel and an engine speed setting means 15 such as a throttle lever are provided.
Are connected to the controller 16. The controller 16 is connected to hydraulic pump control means 17 for variably controlling the input of the hydraulic pump 2. The hydraulic pump 2 is a variable discharge type hydraulic pump, and has a constant output characteristic in the relationship between the discharge pressure and the discharge amount. Also,
The controller 16 is connected to an engine control unit 18 that controls the number of revolutions and output of the engine 1, such as an all-speed electronic governor. The output speed of the engine 1 is detected by the engine speed detecting means 19,
The controller 16 is controlled via the engine speed detecting means 19.
Will be notified. Further, the controller 16 is connected to the first controller 5 and controls its operation. The controller 16 is constituted by a microcomputer or the like, and controls the engine start and each hydraulic actuator according to the shovel operating mechanism 14. The first controller 5 is connected to the generator / motor 4 and the battery 6. The first controller 5 detects the voltage of the battery 6 and notifies the controller 16 of the voltage.

The control operation of the controller 16 during operation will be described with reference to the flowchart of FIG.

STEP 1: The battery voltage of the battery 6 is notified to the controller 16 via the first controller 5 during the operation of the work machine.

STEP 2: It is determined whether or not the battery needs to be charged.

STEP 3: If the battery needs to be charged in STEP 2, the engine 1 is controlled via the engine control means 18 so that the engine speed is set to the set speed (for example, 2000 rpm) set by the engine speed setting means 15. At the same time, the generator / motor 4 is switched to the generator operation via the first controller 5 and the electric power generated by the generator / motor 4 is transferred to the battery 6 via the first controller 5.
Charge the battery.

STEP 4: If battery charging is not required in STEP 2, it is determined whether the input of the hydraulic pump 2 is smaller than the output of the engine 1.

STEP5: If the input of the hydraulic pump 2 is smaller than the output of the engine 1 in STEP4, the battery 6 is not charged via the first controller 5
Control is performed via the engine control means 18 so that the rotation speed of the engine 1 is between the set rotation speed and the high idle rotation speed.

STEP6: If the input of the hydraulic pump 2 is larger than the output of the engine 1 in STEP4, the input of the hydraulic pump 2 is reduced via the hydraulic pump control means 17 and the power is generated via the first controller 5. The motor / motor 4 is switched to the motor operation, the motor output of the generator / motor 4 assists the torque of the engine 1 via the speed increasing mechanism 3, and the number of revolutions of the engine 1 is set via the engine control means 18. Control to be a number.

With such a driving device, the following operation and effect can be obtained. The engine 1 having an output smaller than the maximum input of the hydraulic pump 2 can be used, and thereby efficient use of the engine output can be achieved, thereby saving energy. Moreover, even when the absorption horsepower of the hydraulic pump 2 becomes larger than the output of the engine 1, the engine speed can be stably maintained at the set speed without greatly lowering the engine speed as in the related art. Does not affect the control of the hydraulic actuator, and does not impair the usability of the work machine.

2) Second Embodiment (FIGS. 4 and 5) FIG. 4 is a power transmission system diagram showing a second embodiment. In the power transmission system diagram of FIG. 4, a hydraulic pump 2 is connected to an output of an engine 1 as a power source, and a hydraulic oil discharged from the hydraulic pump 2 passes through a hydraulic control valve 7 to a boom cylinder 9 as a hydraulic actuator. The arm cylinder 10, the bucket cylinder 11, the right traveling drive hydraulic motor 12, and the left traveling drive hydraulic motor 13 are driven. The output of the engine 1 is also connected to a generator / motor 4 via a speed increasing mechanism 3. Generator / motor 4
Is further connected to the second controller 20 and the second controller 20
Is connected to the battery 6. Also, the third controller 21
Is connected to the battery 6, and the third controller 21 is a turning motor / generator 2 for turning the upper turning body.
2 are connected.

The generator / motor 4 is, for example, a three-phase AC induction machine that performs a generator operation or a motor operation, and the operation thereof can be switched by the second controller 20. When the generator / motor 4 performs a generator operation,
The generated AC power is converted into DC by the second controller 20 and charged in the battery 6 connected to the second controller 20. When the generator / motor 4 performs the motor operation, the DC power stored in the battery 6 is converted into AC power by the second controller 20, and the generator / motor 4 is rotationally driven. In this case, the rotating force of the generator / motor 4 is reduced via the speed increasing mechanism 3 at this time and transmitted to the output shaft of the engine 1 to assist the output of the engine 1.

The turning motor / generator 22 is, for example, a three-phase AC induction machine that performs a motor operation or a generator operation, and the operation thereof can be switched by the third controller 21. When the turning motor / generator 22 performs a motor operation, the DC power stored in the battery 6 is converted into AC power by the third controller 21, whereby the turning motor / generator 22 is rotationally driven. . When the turning motor / generator 22 performs a generator operation, the generated AC power is converted into DC by the third controller 21 and charged into the battery 6 connected to the third controller 21. When the turning motor / generator 22 is a three-phase AC induction machine, the third controller 21 includes a converter circuit that rectifies AC power generated by the induction machine into DC power and charges the battery. And an inverter circuit that converts DC power stored in the battery into AC power and rotationally drives the induction machine.

In such a driving device, the following operation and effect can be obtained. The battery 6 can be charged by performing the regenerative braking by operating the revolving electric motor / generator 22 as a generator during braking of the revolving body, so that energy can be reused for other than the revolving drive as compared with the conventional hydraulic regeneration. Become. In addition, by making the turning drive system independent of the hydraulic circuit, there is no effect of mutual interference when performing work by the combined operation of the turning system and other hydraulic actuators, improving the controllability. can get.

FIG. 5 is a block diagram showing a second embodiment. In the block diagram of FIG. 5, a shovel operating mechanism 14 for operating a shovel working member and an engine speed setting means 15 such as a throttle lever are connected to a controller 16. The controller 16
Is connected to a hydraulic pump control means 17 for variably controlling the input of the hydraulic pump 2. The hydraulic pump 2 is a variable discharge type hydraulic pump, and has a constant output characteristic in the relationship between the discharge pressure and the discharge amount. Further, the controller 16 is connected to an engine control means 18 such as an all-speed electronic governor for controlling the number of revolutions and output of the engine 1. The output speed of the engine 1 is detected by the engine speed detecting means 19, and is notified to the controller 26 via the engine speed detecting means 19. Further, the controller 16 is connected to the second controller 20 and controls the operation thereof. This controller 1
Reference numeral 6 is configured by a microcomputer or the like, and controls the engine start and each hydraulic actuator according to the shovel operating mechanism 14. The second controller 20 is connected to the generator / motor 4 and the battery 6 respectively.
The second controller 20 detects the voltage of the battery 6 and notifies the controller 16 of the voltage. Also, a third controller 21 is connected to the battery 6, and the third controller 21 is connected to a turning motor / generator 22 for turning the upper turning body.

The control operation of the controller 16 during operation will be described.

STEP 1: The battery voltage of the battery 6 is notified to the controller 16 via the second controller 20 during the operation of the work machine.

STEP 2: It is determined whether or not the battery needs to be charged.

STEP 3: If the battery needs to be charged in STEP 2, the engine 1 is controlled via the engine control means 18 so that the engine speed is set by the engine speed setting means 15 (for example, 2000 rpm). At the same time, the generator / motor 4 is switched to the generator operation via the second controller 20, and the electric power generated by the generator / motor 4 is charged into the battery 6 via the second controller 20.

STEP 4: If battery charging is not required in STEP 2, it is determined whether the input of the hydraulic pump 2 is smaller than the output of the engine 1.

STEP 5: If the input of the hydraulic pump 2 is smaller than the output of the engine 1 in STEP 4, the battery 6 is not charged through the second controller 20 and the engine 1 is controlled via the engine control means 18. Control is performed so that the rotation speed is between the set rotation speed and the high idle rotation speed.

STEP6: If the input of the hydraulic pump 2 is larger than the output of the engine 1 in STEP4, the input of the hydraulic pump 2 is reduced via the hydraulic pump control means 17 and the power is generated via the second controller 20. The motor / motor 4 is switched to the motor operation, the motor output of the generator / motor 4 assists the torque of the engine 1 via the speed increasing mechanism 3, and the number of revolutions of the engine 1 is set via the engine control means 18. Control to be a number.

With such a driving device, the following operation and effect can be obtained. The engine 1 having an output smaller than the maximum input of the hydraulic pump 2 can be used, and thereby efficient use of the engine output can be achieved, thereby saving energy. Moreover, even when the absorption horsepower of the hydraulic pump 2 becomes larger than the output of the engine 1, the engine speed can be stably maintained at the set speed without greatly lowering the engine speed as in the related art. Does not affect the control of the hydraulic actuator, and does not impair the usability of the work machine. In addition, since the battery 6 can be charged by performing regenerative braking by operating the turning electric motor / generator 22 as a generator during braking of the revolving body, energy can be reused for purposes other than the turning drive, compared to the conventional hydraulic regeneration. Will be possible. In addition, by making the turning drive system independent of the hydraulic circuit, there is an operational effect that there is no mutual interference when performing work by the combined operation of the turning system and other hydraulic actuators, improving controllability. Can be In the first and second embodiments described above, the output of the engine 1 is connected to the generator / motor 4 via the speed increasing mechanism 3, and the output of the engine / motor is higher than the engine speed. Can be used in a high-speed range, thereby providing an effect that the generator / motor can be made compact and space can be saved. Further, in the description of the above-described embodiment, when the engine speed is operated at a predetermined set speed, the case where the engine is operated near the predetermined set speed is also included. Needless to say, the same operation and effect can be obtained in this case.

[0059]

As described above, according to the present invention, in a driving device for a working machine, a battery is charged by a generator / motor connected to an engine during a light load operation and the electric power stored in the battery during a high load operation. A first controller that drives the generator / motor using the to assist the engine output, and a controller that controls the engine speed to be a predetermined set speed even when the generator / motor operates as a generator. Equipped, so you can use an engine with a capacity smaller than the maximum input of the hydraulic pump,
In addition, since the engine speed can be stably maintained, the usability of the working machine is not deteriorated.

Further, the present invention provides a driving device for a working machine, wherein a battery is charged by a generator / motor connected to an engine during a light load operation, and a power is stored using the electric power stored in the battery during a high load operation. A second controller for driving the machine / motor and assisting the engine output; a revolving motor / generator for the revolving body and a battery for charging by the revolving motor / generator at the time of turning braking and being stored in the battery at the time of turning. Since the third controller for driving the turning motor / generator using electric power is provided, energy can be reused for driving other than the turning system, and further energy saving can be achieved.

[Brief description of the drawings]

FIG. 1 is a power transmission system diagram according to a first embodiment of the present invention.

FIG. 2 is a block diagram according to the first embodiment of the present invention.

FIG. 3 is a flowchart according to the first embodiment of the present invention.

FIG. 4 is a power transmission system diagram according to a second embodiment of the present invention.

FIG. 5 is a block diagram according to a second embodiment of the present invention.

FIG. 6 is an overall structural view of a self-propelled shovel.

FIG. 7 is a graph showing a relationship between a discharge pressure and a discharge flow rate of a hydraulic pump.

FIG. 8 is a graph showing the relationship between the output speed of the engine, torque and output.

[Explanation of symbols]

 1: engine 2: hydraulic pump 3: speed increasing mechanism 4: generator / motor 5: first controller 6: battery 16: controller 20: second controller 21: third controller 22: turning motor / generator

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D003 AA01 AB02 AB06 AB07 BA05 CA02 DA04 DB03 DB08 FA02 3G093 AA04 AA10 AA15 AA16 AB01 BA19 DA01 DB19 EA03 EB00 EB06 EB07 FA11 5H607 AA01 BB01 BB02 CC01 CC05 EE24 FF22

Claims (4)

[Claims] An engine, a hydraulic pump coupled to the engine and having a maximum input greater than the output of the engine, a generator / motor coupled to an output shaft of the engine for performing a generator operation or a motor operation, A battery for storing the electric power generated by the generator / motor; and a switch connected to the generator / motor and the battery for switching the operation of the generator / motor. A work controller comprising: a first controller configured to charge the battery with electric power generated by rotation of an electric motor and to supply the electric power stored in the battery to the electric generator and electric motor to rotate the electric motor when the electric motor operates. The driving device according to claim 1, further comprising a controller connected to the first controller, wherein the controller is configured such that an input of the hydraulic pump is smaller than an output of the engine. At this time, the engine is operated between a predetermined set rotation speed and a high idle rotation speed, and when the input of the hydraulic pump is larger than the engine output, the input of the hydraulic pump is reduced and the battery is discharged. A driving device for a working machine, wherein the generator / motor is operated as an electric motor by using the electric power stored in the motor to supplement the engine output to operate the engine near a set rotation speed. 2. An engine, a hydraulic pump connected to the engine and having a maximum input greater than an output of the engine, a generator / motor connected to an output shaft of the engine for performing a generator operation or a motor operation, A battery for storing the electric power generated by the generator / motor; and a switch connected to the generator / motor and the battery for switching the operation of the generator / motor. A second controller for charging the battery with the electric power generated by the rotation of the motor and supplying the electric power stored in the battery to the generator / motor in the case of the motor operation to rotate the work machine; A turning motor / generator for turning the body to perform a motor operation or a generator operation, and the turning motor / generator connected to the turning motor / generator and the battery; When the operation of the motor / generator is switched and the revolving structure is swiveled, the turning motor / generator is operated by the motor to drive the turning motor / generator using the electric power stored in the battery. A third controller that, when braking the revolving structure, operates the revolving motor / generator as a generator to charge the battery with electric power generated by the revolving motor / generator. A drive unit for a working machine, which is a feature. 3. The drive device for a work machine according to claim 2, further comprising: a controller connected to the second controller and the third controller, wherein the controller receives an input of the hydraulic pump from the engine output. When it is smaller, the engine is operated between a predetermined set speed and a high idle speed, and when the input of the hydraulic pump is larger than the engine output, the input of the hydraulic pump is reduced,
A driving device for a working machine, wherein the generator and the electric motor are operated by an electric motor using electric power stored in the battery to supplement an engine output and operate the engine near a set rotation speed. 4. The work machine drive device according to claim 1, wherein the engine and the generator / motor are connected via a speed increasing device. The drive of the machine.