KR20180110037A - Control system and control method of hybrid construction machine - Google Patents

Abstract

The control system 100 of the hybrid construction machine includes main pumps 71 and 72, a regenerative motor 88 rotationally driven by a working fluid, a motor generator 91 connected to the regenerative motor 88, And the controller 90. When the controller 90 determines that the voltage of the capacitor 26 is smaller than the regeneration start voltage Vmin when the actuator is not in operation, The flow rates of the working fluid supplied from the main pumps 71 and 72 to the regenerative motor 88 are set to be equal to or greater than the flow rates of the working fluid discharged from the main pumps 71 and 72 when the actuators are operating .

Description

Control system and control method of hybrid construction machine

The present invention relates to a control system and a control method of a hybrid construction machine.

JP2015-137752A discloses a hybrid construction machine in which an engine and a rotary electric machine driven by electric power of a power storage unit are used as a power source in combination. In this hybrid construction machine, regenerative control is performed in which the regenerative motor is rotationally driven by operating fluid returned from the actuator, and the power regenerated in the rotational electric machine connected to the regenerative motor is charged in the power storage unit. In addition, in this hybrid construction machine, besides supplying the hydraulic fluid from the main pump driven by the engine to the actuator, assist control for supplying the hydraulic fluid to the actuator from the assist pump connected to the rotary electric machine and the regenerative motor is performed.

In the hybrid construction machine disclosed in JP2015-137752A, when the assist control is performed when the voltage of the power storage unit is low, the power storage unit is in an overdischarged state, and the durability of the power storage unit may be lowered. To solve such a problem, it has been considered to charge the power storage unit while the actuator is not operated, and increase the voltage of the power storage unit. However, if the time during which the actuator is not operated is short, the voltage of the power storage unit can not be increased sufficiently, and there is a possibility that the power storage unit is prevented from being overdischarged.

An object of the present invention is to improve durability of a power storage unit of a hybrid construction machine.

According to one embodiment of the present invention, a control system of a hybrid construction machine includes: a variable capacity type fluid pressure pump for supplying a working fluid to a fluid pressure actuator; and a working fluid which is returned from the fluid pressure actuator or from the fluid pressure pump A regenerative motor rotatably driven by a supplied working fluid; rotating electric machines connected to the regenerative motor; a power storage unit for collecting electric power generated by the rotating electric machine; and a supply unit for supplying a working fluid from the fluid pressure pump to the regenerative motor Wherein when the fluid pressure actuator is not operating and it is determined that the charged amount of the power storage unit is smaller than the first predetermined amount, the control unit controls the fluid pressure pump Wherein when the flow rate of the working fluid is higher than the flow rate of the fluid pressure when the fluid pressure actuator is operating The above flow rate of the working fluid discharged from Pro and controls the hydraulic pump so.

According to another aspect of the present invention, there is provided a fluid pressure actuator comprising: a variable displacement fluid pressure pump for supplying a working fluid to a fluid pressure actuator; and a working fluid supplied from the fluid pressure actuator, A control method for controlling a hybrid construction machine having a regenerative motor, a rotary electric machine connected to the regenerative motor, and a power storage unit for collecting electric power generated by the rotary electric machine, The flow rate of the working fluid supplied from the fluid pressure pump to the regenerative motor is set to be smaller than the first predetermined amount when the fluid pressure actuator is not operating and the detected amount of charge of the power storage unit is smaller than the first predetermined amount , And when the fluid pressure actuator is operating, To be less than the flow rate of the working fluid output.

1 is a circuit diagram showing a control system of a hybrid construction machine according to an embodiment of the present invention.
[Fig. 2] Fig. 2 is a flowchart of non-operation regeneration control in a control system of a hybrid construction machine.
[Fig. 3] Fig. 3 is a graph for explaining the non-operation regeneration control in the control system of the hybrid construction machine.
[Fig. 4] Fig. 4 shows a part of a circuit diagram of a modification of the control system of the hybrid construction machine according to the embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, with reference to Fig. 1, the overall configuration of a control system 100 of a hybrid construction machine according to an embodiment of the present invention will be described. In the present embodiment, a case where the hybrid construction machine is a hydraulic excavator will be described. In the hydraulic excavator, hydraulic oil is used as the working fluid.

The hydraulic excavator has first and second main pumps 71 and 72 as fluid pressure pumps. The first and second main pumps 71 and 72 are variable displacement pumps capable of adjusting the angle of inclination of the swash plate. The first and second main pumps 71 and 72 are driven by the engine 73 to coaxially rotate.

The generator 73 is provided with a generator 74 that generates power using the power of the engine 73. The electric power generated by the generator 74 is charged to the capacitor 26 as a power storage unit through the charger 25. [ The charger 25 can charge the capacitor 26 even when the charger 25 is connected to the power supply 27 for normal household use.

The capacitor 26 is constituted by an electric double layer capacitor. The capacitor 26 is provided with a temperature sensor 26a for detecting the temperature of the capacitor 26, a voltage sensor (not shown) for detecting the voltage of the capacitor 26, A current sensor (not shown) is installed. The temperature sensor 26a outputs an electric signal corresponding to the detected temperature of the capacitor 26 to the controller 90 as a control unit. The capacitor 26 may be a secondary battery such as a lithium ion battery or a nickel metal hydride battery.

The hydraulic oil discharged from the first main pump 71 is supplied to the first circuit system 75. The first circuit system 75 includes an operation valve 2 for controlling the swing motor 76 in order from the upstream side, an operation valve 3 for controlling the arm cylinder (not shown), a boom cylinder 77 An operation valve 5 for controlling a spare attachment (not shown), and a first running motor (not shown) for a left running run And has an operation valve 6 for controlling the operation. The swing motor 76, the arm cylinder, the boom cylinder 77, the hydraulic device connected to the spare attachment, and the first running motor correspond to a fluid pressure actuator (hereinafter simply referred to as "actuator") .

Each of the operation valves 2 to 6 controls the flow rate of the discharge oil supplied to each of the actuators from the first main pump 71 and controls the operation of each actuator. Each of the operation valves 2 to 6 is operated by a pilot pressure supplied by an operator of the hydraulic excavator manually operating the operation lever.

Each of the operation valves 2 to 6 is connected to the first main pump 71 through a neutral flow path 7 and a parallel flow path 8 which are parallel to each other. A first supply pressure sensor 63 for detecting the pressure of the operating oil supplied from the first main pump 71 to the neutral passage 7 is provided on the upstream side of the operating valve 2 in the neutral passage 7. [ On the upstream side of the operation valve 2 in the neutral passage 7 is opened a main relief valve 7 which is opened when the working oil pressure of the neutral passage 7 exceeds a predetermined main relief pressure, (65).

On the downstream side of the operating valve 6 in the neutral flow path 7 is provided an on-off valve 9 having a solenoid connected to the controller 90 and capable of shutting off the working fluid of the neutral flow path 7. The on-off valve 9 maintains the fully open state in the normal state. The opening / closing valve 9 is converted into a closed state by a command from the controller 90.

On the downstream side of the on-off valve 9 in the neutral passage 7, a pilot pressure generating mechanism 10 for generating a pilot pressure is provided. The pilot pressure generating mechanism 10 generates a high pilot pressure when the flow rate of the hydraulic oil passing through is large and generates a low pilot pressure when the flow rate of the hydraulic oil passing therethrough is small.

The neutral passage 7 leads all or a part of the operating oil discharged from the first main pump 71 to the tank when all of the operation valves 2 to 6 are in the neutral position or in the vicinity of the neutral position. In this case, since a flow rate passing through the pilot pressure generating mechanism 10 is increased, a high pilot pressure is generated.

On the other hand, when the operation valves 2 to 6 are switched to the full stroke state, the neutral flow path 7 is closed and the flow of the hydraulic oil is eliminated. In this case, the flow rate passing through the pilot pressure generating mechanism 10 is almost lost, and the pilot pressure is maintained at zero. However, depending on the operation amount of the operation valves 2 to 6, part of the operating oil discharged from the first main pump 71 is led to the actuator, and the remainder is led to the tank from the neutral flow path 7. Therefore, the pilot pressure generating mechanism 10 generates the pilot pressure in accordance with the flow rate of the hydraulic fluid in the neutral flow path 7. That is, the pilot pressure generating mechanism 10 generates a pilot pressure corresponding to the operation amount of the operation valves 2 to 6.

A pilot flow path 11 is connected to the pilot pressure generating mechanism 10. The pilot pressure generated in the pilot pressure generating mechanism 10 is induced in the pilot flow passage 11. [ The pilot pressure generating mechanism 10 is connected to the regulator 12 that controls the discharge capacity (the gentle angle of the swash plate) of the first main pump 71 through the pilot flow passage 11. [

The regulator 12 controls the tilting angle of the swash plate of the first main pump 71 in proportion to the pilot pressure of the pilot flow path 11 (the proportionality constant is negative). Thereby, the regulator 12 controls the amount of pushing (pushing-out amount) per one rotation of the first main pump 71. That is, the discharge amount of the first main pump 71 changes in accordance with the pilot pressure of the pilot flow passage 11. When the pilot valves of the pilot passages 11 become zero as the operation valves 2 to 6 are switched to the full stroke and the flow of the neutral passages 7 disappears, do. At this time, the pressure amount per one rotation of the first main pump 71 becomes maximum.

The pilot flow path 11 is provided with a first pressure sensor 13 for detecting the pressure of the pilot flow path 11. The pressure detected by the first pressure sensor 13 is outputted to the controller 90 as a pressure signal.

The hydraulic oil discharged from the second main pump 72 is supplied to the second circuit system 78. The second circuit system 78 includes an operation valve 14 for controlling a second running motor (not shown) for space travel (right running), a bucket cylinder (not shown) An operation valve 16 for controlling the boom cylinder 77 and an operation valve 17 for the arm 2 for controlling the arm cylinder (not shown). The second traveling motor, the bucket cylinder, the boom cylinder 77, and the arm cylinder correspond to a fluid pressure actuator (hereinafter simply referred to as an " actuator ").

Each of the operating valves 14 to 17 controls the flow rate of the discharged oil supplied to each of the actuators from the second main pump 72 to control the operation of each actuator. Each of the operation valves 14 to 17 is operated by a pilot pressure supplied by an operator of the hydraulic excavator manually operating the operation lever.

The respective operation valves 14 to 16 are connected to the second main pump 72 through the neutral passage 18 and the parallel passage 19 which are parallel to each other. A second supply pressure sensor 64 for detecting the pressure of the operating oil supplied from the second main pump 72 to the neutral flow passage 18 is provided on the upstream side of the operating valve 14 in the neutral flow passage 18. A main relief valve (not shown) is provided on the upstream side of the operating valve 14 in the neutral passage 18 to open when the operating oil pressure of the neutral passage 18 exceeds a predetermined main relief pressure, (66).

The main relief valves 65 and 66 may be provided in at least one of the first circuit system 75 and the second circuit system 78. [ When the main relief valve is provided only in one of the first circuit system 75 and the second circuit system 78, the hydraulic fluid from the other of the first circuit system 75 and the second circuit system 78, And connected to be led to the relief valve. In this way, when a single main relief valve is provided, the main relief valve is shared between the first circuit system 75 and the second circuit system 78. In this case, only one supply pressure sensor is provided, and the first circuit system 75 and the second circuit system 78 are shared.

On the downstream side of the operating valve 17 in the neutral flow path 18 is provided a solenoid connected to the controller 90 to provide an on-off valve 21 capable of shutting off the operating fluid of the neutral flow path 18. The on-off valve 21 maintains the open state in the normal state. The on-off valve 21 is switched to a closed state by a command from the controller 90.

On the downstream side of the on-off valve 21 in the neutral passage 18, a pilot pressure generating mechanism 20 for generating a pilot pressure is provided. The pilot pressure generating mechanism 20 has the same function as the pilot pressure generating mechanism 10 on the first main pump 71 side.

A pilot flow path 22 is connected to the pilot pressure generating mechanism 20. The pilot pressure generated by the pilot pressure generating mechanism 20 is induced in the pilot flow path 22. The pilot pressure generating mechanism 20 is connected to a regulator 23 that controls the discharge capacity (the gentle angle of the swash plate) of the second main pump 72 through the pilot flow path 22.

The regulator 23 controls the tilting angle of the swash plate of the second main pump 72 in proportion to the pilot pressure of the pilot flow path 22 (proportional constant is negative). Thereby, the regulator 23 controls the amount of pressurization per rotation of the second main pump 72. [ That is, the discharge amount of the second main pump changes in accordance with the pilot pressure of the pilot flow path 22. The flow of the neutral flow path 18 disappears and the pilot pressure of the pilot flow path 22 becomes zero so that the second main pump 72 has a maximum inclination angle of do. At this time, the amount of pressure per rotation of the second main pump 72 becomes maximum.

The pilot flow path 22 is provided with a second pressure sensor 24 for detecting the pressure of the pilot flow path 22. The pressure detected by the second pressure sensor 24 is outputted to the controller 90 as a pressure signal.

Next, the swing motor 76 will be described.

The actuator ports of the operation valve 2 are connected to the flow paths 28 and 29 communicating with the swing motor 76. Relief valves 30 and 31 are connected to the flow paths 28 and 29, respectively. When the operating valve 2 is held at the neutral position, the actuator port is closed, and the swing motor 76 maintains the stopped state.

The flow path 28 is connected to the first main pump 71 and the flow path 29 is communicated with the tank when the operation valve 2 is switched from the neutral position to the one side in the state in which the swing motor 76 is stopped, do. As a result, the hydraulic oil is supplied from the oil passage 28 to rotate the swing motor 76 in one direction, and the return oil from the swing motor 76 is returned to the tank through the oil passage 29 . When the operating valve 2 is switched to the other side, the flow path 29 is connected to the first main pump 71, and the flow path 28 communicates with the tank. As a result, the hydraulic oil is supplied from the oil passage 29 to rotate the swing motor 76 in the other direction, and the return oil from the swing motor 76 is returned to the tank through the oil passage 28.

Next, the boom cylinder 77 will be described.

The actuator ports of the operation valve 16 are connected to the flow paths 32 and 35 communicating with the boom cylinder 77. When the operating valve 16 is held at the neutral position, the actuator port is closed, and the boom cylinder 77 is kept stationary.

When the operating valve 16 is switched from the neutral position to one side in a state in which the boom cylinder 77 is stopped and the operating oil discharged from the second main pump 72 flows through the oil passage 32 into the boom cylinder 77 The return oil from the rod chamber 34 is returned to the tank through the oil passage 35 while being supplied to the piston chamber 33. Thereby, the boom cylinder 77 is extended. The operating oil discharged from the second main pump 72 is supplied to the rod chamber 34 of the boom cylinder 77 via the flow path 35 and the piston chamber 33 The return oil is returned to the tank through the oil passage 32. As a result, the boom cylinder 77 shrinks.

The boom second-speed operation valve 4 of the first circuit system 75 is switched in conjunction with the operation valve 16 in accordance with the operation amount of the boom operation lever. An electromagnetic proportional tightening valve 36 whose opening degree is controlled by the controller 90 is provided in the oil passage 32 connecting the piston chamber 33 of the boom cylinder 77 and the operating valve 16. The electronic proportional tightening valve 36 maintains the fully open position in the normal state.

The control system 100 of the hybrid construction machine is provided with a regenerative device for performing regenerative control for recovering the energy of the hydraulic fluid discharged from the swing motor 76 and the boom cylinder 77. Hereinafter, the regenerative apparatus will be described.

Regenerative control by the regenerative apparatus is executed by the controller 90. [ The controller 90 includes a CPU (Central Processing Unit) that executes regeneration control, a ROM (Read Only Memory) that stores control programs and setting values necessary for processing operations of the CPU, (Random Access Memory).

First, the swing regenerative control for performing energy regeneration using the hydraulic fluid from the swing motor 76 will be described.

The flow paths 28 and 29 connected to the swing motor 76 are connected to the swirl regeneration flow path 47 for guiding the hydraulic fluid from the swing motor 76 to the regeneration motor 88 for regeneration. Each of the flow paths 28 and 29 is provided with check valves 48 and 49 that allow only the flow of the working fluid to the circulation regeneration flow path 47. The swirl regeneration flow path 47 is connected to the regenerative motor 88 through the convergence regeneration flow path 46.

The regenerative motor 88 is a variable displacement type motor that can adjust the inclined plate angle of the swash plate and is connected to the motor generator 91 as a rotary electric machine serving as a generator for coaxial rotation. The regenerative motor 88 is rotationally driven by the operating oil that is discharged from the swing motor 76 and the boom cylinder 77 and circulated through the combined regeneration flow path 46. The regenerative motor 88 is rotationally driven by the direct supply of operating fluid discharged from the first and second main pumps 71 and 72 as described later. The tilting angle of the swash plate of the regenerative motor 88 is controlled by the tilting angle controller 38. The syllable angle controller 38 is controlled by the output signal of the controller 90.

The regenerative motor 88 is capable of rotating the motor generator 91. When the motor generator 91 functions as a generator, the generated regenerative electric power is charged to the capacitor 26 through the inverter 92. [ The regenerative motor 88 and the motor generator 91 may be directly connected or connected via a speed reducer.

An upstream side of the regenerative motor 88 is an upstream side of an upstream side of the regenerative motor 88 when the supply flow rate of the operating fluid to the regenerative motor 88 becomes insufficient, Suction upstream passage 61) are connected. The suction passage 61 is provided with a check valve 61a which allows only the flow of the working oil from the tank to the joining regeneration passage 46. [

An electronic switching valve 50 is provided in the swirl regeneration flow path 47 for switching to a signal output from the controller 90. A pressure sensor 51 is provided between the electromagnetic switching valve 50 and the check valves 48 and 49 for detecting the turning pressure at the turning operation of the swing motor 76 or the brake pressure at the time of the brake operation. The pressure detected by the pressure sensor 51 is output to the controller 90 as a pressure signal.

During the brake operation in which the operating valve 2 is switched to the neutral position while the swing motor 76 is being turned by the hydraulic oil supplied through the oil passages 28 and 29, The working oil flows into the orbital regeneration flow path 47 through the check valves 48 and 49 and is guided to the regenerative motor 88.

A safety valve 52 is provided on the downstream side of the electromagnetic switching valve 50 in the circulation recovery flow path 47. The safety valve 52 maintains the pressure of the flow paths 28 and 29 so that the swing motor 76 is rotated about the circumference of one revolution , escape lash).

The controller 90 excites the solenoid of the electromagnetic switching valve 50 when it is judged that the detected pressure of the pressure sensor 51 is equal to or higher than the rotational speed regeneration start pressure. As a result, the electromagnetic switching valve 50 is switched to the open position and the swing regeneration is started. When the controller 90 determines that the detected pressure of the pressure sensor 51 is lower than the turn-around regeneration start pressure, the solenoid of the electromagnetic switching valve 50 is set to non-excitation. As a result, the electromagnetic switching valve 50 is switched to the closed position and the swing regeneration is stopped.

Next, the boom regeneration control for performing energy regeneration using the operating oil from the boom cylinder 77 will be described.

The flow path 32 is connected to a boom regeneration flow path 53 which branches off between the piston side chamber 33 and the electromagnetic proportional pressure valve 36. The boom regeneration flow path 53 is a flow path for guiding return operating oil from the piston chamber 33 to the regenerative motor 88. The circulation regeneration flow path 47 and the boom regeneration flow path 53 join together and are connected to the combined regeneration flow path 46.

The boom regeneration flow path 53 is provided with an electromagnetic switching valve 54 which is switch-controlled to a signal output from the controller 90. [ When the solenoid is not energized, the electromagnetic switching valve 54 is switched to a closed position (shown in the drawing) to shut off the boom regeneration flow path 53. The electromagnetic switching valve 54 is switched to the opened position when the solenoid is energized to open the boom regeneration flow path 53 to allow only the flow of the hydraulic fluid from the piston side chamber 33 to the convergence regeneration flow path 46.

The controller 90 determines whether the operator intends to extend or contract the boom cylinder 77 based on the detection result of the operation direction of the operation valve 16 and a sensor . When the boom cylinder 77 is determined to be extended, the controller 90 keeps the electromagnetic proportional tightening valve 36 at the deployed position in the normal state and holds the electromagnetic switching valve 54 in the closed position. On the other hand, when it is judged that the boom cylinder 77 is contracted, the controller 90 calculates the contraction speed of the boom cylinder 77 requested by the operator according to the operation amount of the operation valve 16, The throttle valve 36 is closed to switch the electromagnetic switching valve 54 to the open position. Thus, the entire amount of return operating oil from the boom cylinder 77 is guided to the regenerative motor 88, and the boom is regenerated.

Next, the assist pump 89 is driven by the energy regenerated by the regenerative control described above, and the energy of the operating oil discharged from the assist pump 89 causes the first main pump 71 and the second main pump 72 ) Is assisted.

The assist pump 89 is a variable displacement pump capable of adjusting the angle of inclination of the swash plate and rotates coaxially with the regenerative motor 88 and the motor generator 91. [ It is possible to rotationally drive the assist pump 89 by the driving force when the motor generator 91 is used as an electric motor and the driving force by the regenerative motor 88. [ The rotation number of the assist pump 89, that is, the rotation number of the motor generator 91 to which the assist pump 89 is connected, is controlled by the controller 90 connected to the inverter 92. The tilting angle of the swash plate of the assist pump (89) is controlled by the tilting angle controller (37). The syllable angle controller 37 is controlled by the output signal of the controller 90.

The discharge passage 39 of the assist pump 89 is provided with a first assist passage 40 joining to the discharge side of the first main pump 71 and a second assist passage 40 joining to the discharge side of the second main pump 72, And branches to the assist flow path 41. A high-pressure selection switching valve 42 is interposed in the branching portion. The first assist flow path 40 is provided with a first check valve 44 allowing only the flow of the working fluid from the discharge flow path 39 to the discharge side of the first main pump 71, A second check valve 45 that allows only the flow of the hydraulic fluid from the discharge passage 39 to the discharge side of the second main pump 72 is provided.

The high-pressure selection switching valve 42 is a spool-type switching valve at the 3-port 3 position. The high-pressure selection switching valve 42 is provided with pilot chambers 42a and 42b at both ends of the spool. The working oil in the first assist passage 40 on the first main pump 71 side is supplied from the first check valve 44 to the one pilot chamber 42a through the first pilot passage 43a. The working oil in the second assist passage 41 on the second main pump 72 side is supplied from the second check valve 45 to the other pilot chamber 42b through the second pilot passage 43b. In order to prevent the spool of the high-pressure selection switching valve 42 from abruptly moving, a depression tightening (not shown) is provided in each of the pilot passages 43a and 43b.

The high-pressure selection switching valve 42 is held at a neutral position by a centering spring provided at both ends of the spool. The discharge oil of the assist pump 89 is supplied to the first assist flow path 40 and the second assist flow path 41 in a state in which the high pressure selection switching valve 42 is held at the neutral position.

The high pressure selection switching valve 42 is opened and closed by the communication between the discharge passage 39 and the second assist passage 41 when the pilot pressure of the one pilot chamber 42a is higher than the pilot pressure of the other pilot chamber 42b And is switched to the first switching position for communicating the discharge passage 39 with the first assist passage 40. [ When the pilot pressure in the other pilot chamber 42b is higher than the pilot pressure in the one pilot chamber 42a, the high-pressure selection switch valve 42 is switched between the discharge passage 39 and the first assist passage 40, And is switched to the second switching position for communicating the discharge flow passage 39 and the second assist flow passage 41 with each other.

That is, the high-pressure selection switching valve 42 selects the high-pressure side flow passage among the first assist flow passage 40 and the second assist flow passage 41 and supplies the discharge oil of the assist pump 89. Depending on the differential pressure between the one pilot chamber 42a and the other pilot chamber 42b, the high-pressure selection switch valve 42 is located at a position intermediate the neutral position and the first switching position, And the second switching position. In this case, a large amount of discharge oil is supplied to the high-pressure passage and a small amount of the discharge oil is supplied to the low-pressure passage.

When the assist pump 89 is rotated by the driving force of the motor generator 91, the assist pump 89 assists the output of at least one of the first main pump 71 and the second main pump 72. The degree of assisting of both the first main pump 71 and the second main pump 72 does not require a proportional electromagnetic throttle valve or the like controlled by the controller 90, . ≪ / RTI >

When the assist pump 89 is rotated by the driving force of the motor generator 91, the operating fluid is supplied to the regenerating motor 88 through the confluence regenerating flow path 46. When the regenerating motor 88 rotates, The rotational force of the regenerative motor 88 serves as an assisting force with respect to the motor generator 91. [ Therefore, the power consumption of the motor generator 91 for rotating the assist pump 89 by the rotational force of the regenerative motor 88 can be reduced. When the regenerative motor 88 becomes the driving source and the motor generator 91 is used as the generator, the angle of inclination of the swash plate of the assist pump 89 is set to zero, and the assist pump 89 becomes almost no load .

Next, the surplus hydraulic fluid discharged from the first and second main pumps 71 and 72 is directly supplied to the regenerative motor 88 without passing through the respective actuators, Flow regeneration control will be described. The surplus flow regeneration control is executed by the controller 90 in the same manner as the swing regeneration control and the boom regeneration control.

The first main pump 71 is branched from the first assist flow path 40 communicating with the discharge side of the first main pump 71 in order to directly direct the working fluid discharged from the first main pump 71 to the regenerative motor 88, A pump regeneration flow path 55 is provided. One end of the first main pump regeneration passage 55 is connected to the first main pump 71 side of the first check valve 44 of the first assist passage 40 and the other end thereof is connected to the first main pump 71 side of the first assist passage 40 via the merging passage 57 Is connected to the confluence regeneration flow path (46). Likewise, in order to directly direct the working fluid discharged from the second main pump 72 to the regenerative motor 88, the second auxiliary flow path 41, which branches from the second assist flow path 41 communicating with the discharge side of the second main pump 72, 2 main pump regeneration flow path 56 is provided. One end of the second main pump regeneration passage 56 is connected to the second main pump 72 side of the second check valve 45 of the second assist passage 41 and the other end of the second main pump regeneration passage 56 is connected through the merging passage 57 Is connected to the confluence regeneration flow path (46). A check valve 60 is provided in the confluent flow path 57 to allow only the flow of the hydraulic fluid from the first and second main pumps 71 and 72 to the confluent regeneration flow path 46.

The first and second main pump regenerating passages 55 and 56 are provided with solenoid valves 58 and 59, respectively. The solenoid valves 58 and 59 have solenoids connected to the controller 90. When the solenoids are not energized, the solenoids are switched to the closed position (position shown in the drawing) and switched to the open position when the solenoids are energized.

The controller 90 excites the solenoid of the solenoid valve 58 when it is judged that the detected value of the first supply pressure sensor 63 reaches the main relief pressure of the main relief valve 65. As a result, the solenoid valve 58 is switched to the opened position, and surplus operating fluid discharged from the first main pump 71 and discharged to the tank through the main relief valve 65 flows into the first main pump regeneration flow path (55), and the energy is recovered by the regenerative motor (88).

Likewise, when the controller 90 determines that the detected value of the second supply pressure sensor 64 reaches the main relief pressure of the main relief valve 66, the solenoid of the solenoid valve 59 is energized. As a result, the solenoid valve 59 is switched to the opened position, and surplus hydraulic fluid discharged from the second main pump 72 and discharged to the tank through the main relief valve 66 is discharged to the second main pump regeneration flow path (56), and the energy is recovered by the regenerative motor (88).

As such, surplus hydraulic fluid discharged from the first and second main pumps 71 and 72 is guided to the regenerative motor 88 via the solenoid valves 58 and 59. The regenerative motor 88 rotates the motor generator 91 to generate electric power and the electric power generated by the motor generator 91 is charged to the capacitor 26 through the inverter 92. [ As a result, surplus flow regeneration by surplus hydraulic fluid discharged from the first and second main pumps 71 and 72 is performed.

Furthermore, in this embodiment, when the first and second main pump regeneration flow passages 55 and 56 and the electromagnetic valves 58 and 59 used for the surplus flow regeneration control described above are used and when the actuators are not operated The controller 90 executes the regeneration control at the time of non-operation in which the operating fluid discharged from the first and second main pumps 71 and 72 is directly supplied to the regenerative motor 88 and the energy of the operating fluid is regenerated.

Here, when the above-described assist control is executed when the voltage of the capacitor 26 is low, the voltage of the capacitor 26 becomes close to the lower limit voltage of use, and as a result, the durability of the capacitor 26 may deteriorate. In order to avoid such a situation, it is necessary to charge the capacitor 26 before the assist control, that is, while the actuators are not operated, so that the voltage of the capacitor 26 needs to be increased. However, if the time when each actuator is not operated is short, the voltage of the capacitor 26 can not be sufficiently increased, and there is a possibility that the capacitor 26 can not be overdischarged.

Therefore, in the non-operation regeneration control, the first and second main pumps 71 and 72 are driven by the regenerative motor (not shown) so as to rapidly increase the voltage of the capacitor 26 even when the time when each actuator is not operated is short. 88 so as to be equal to or greater than the flow rate of the hydraulic fluid discharged from the first and second main pumps 71, 72 when the respective actuators are operating.

Hereinafter, non-operating regeneration control will be described with reference to Figs. 1 to 3. Fig. Fig. 2 is a flowchart when non-operating regeneration control is executed, and Fig. 3 is a diagram showing the relation between the non-operating regenerative control and the voltage of the capacitor 26. Fig.

The controller 90 energizes the solenoid of the solenoid valve 58 to switch the solenoid valve 58 to the open position when the condition for executing the non-operating regeneration control described later is satisfied 9 to energize the solenoid to switch the open / close valve 9 to the closed position. The pilot pressure is zero and the hydraulic angle of the first main pump 71, that is, the discharge amount is set to be zero, since the opening / closing valve 9 is switched to the closed position and the inflow of the working oil into the pilot pressure generating mechanism 10 is cut off. Max. The hydraulic fluid discharged from the first main pump 71 is guided to the combined regeneration flow path 46 through the first main pump regenerating flow path 55 and the energy thereof is recovered by the regenerating motor 88.

Likewise, the controller 90 sets the discharge amount of the second main pump 72 to the maximum, and distributes the operating fluid discharged from the second main pump 72 to the regenerative motor (not shown) through the second main pump regeneration flow path 56 88 < / RTI >

The operating fluid discharged from the first and second main pumps 71 and 72 controlled to have the maximum discharge amount is guided to the regenerative motor 88 via the solenoid valves 58 and 59, And rotates the motor generator 91 together with the motor 88. At this time, by increasing the torque command value to the motor generator 91 in accordance with the flow rate of the operating oil supplied to the regenerative motor 88, the electric power generated by the motor generator 91 can be increased. The electric power generated by the motor generator 91 is quickly charged to the capacitor 26 via the inverter 92. As described above, in the non-operation regeneration control, the first and second main pumps 71 and 72 are controlled so that the discharge amount is maximized. Therefore, even if the time when each actuator is not operated is short, Can be rapidly increased.

Instead of maximizing the discharge amount of both the first and second main pumps 71 and 72, the discharge amount of only one of the first and second main pumps 71 and 72 is maximized You can control it. In this case, the angle of inclination of the other pump is kept at a minimum state, and the amount of discharge is a standby flow rate which is a flow rate when the actuator is not operated. In this way, even when the discharge amount of either one of the first and second main pumps 71 and 72 is maximized, it is possible to supply the regenerative motor 88 from both the first and second main pumps 71 and 72 The regenerative motor 88 connected to the motor generator 91 is driven in a state where the angle of inclination is the maximum or the motor efficiency is high and the electric power generated by the motor generator 91 is quickly And can be efficiently increased.

In place of the configuration in which the pilot pressure is made zero by closing the opening and closing valves 9 and 21 and the discharge amount of the first and second main pumps 71 and 72 is maximized, The first and second main pumps 71 and 72 may be controlled so as to maximize the discharge amount or to maximize the pump efficiency by electrically controlling the angle of inclination of the pumps 71 and 72, respectively. In order to recover the energy of the supplied operating oil by the regenerative motor 88 when the discharge amount of both the first and second main pumps 71 and 72 is maximized, ). Therefore, the first and second main pumps 71 and 72 are electrically controlled electrically, and the discharge amounts of the first and second main pumps 71 and 72, respectively, Can be adjusted. The flow rate of the hydraulic fluid supplied to the regenerative motor 88 from both of the first and second main pumps 71 and 72 increases so that the regenerative motor 88 connected to the motor generator 91, It is possible to quickly and efficiently increase the electric power generated by the motor generator 91. The motor generator 91 is driven with the maximum angle or the high motor efficiency.

Next, the non-operation regeneration control executed by the controller 90 will be described in detail with reference to a flowchart shown in Fig.

First, at step S11, the controller 90 determines whether each actuator is being operated by the operator. Whether or not each actuator is operated is determined based on the displacement of each of the operation valves 2 to 6 and 14 to 17 and the displacement of each operation lever operated by the operator. The parameters used in the determination in this step are not limited to the displacements of the respective operation valves 2 to 6 and 14 to 17 and may be any parameters as long as they change with respect to the operation of the actuators. , And the pressure of the operating oil in the piping connected to each actuator may be acceptable.

When it is determined in step S11 that the actuators are being operated, the routine proceeds to step S12. When the regeneration by the non-operation regeneration control has already been executed (when the regeneration flag at the time of non-operation is " 1 & The regeneration is stopped and the regeneration flag at the time of non-operation is set to " 0 ". When the regeneration by the regenerative control at the time of non-operation is not executed, that is, when the regeneration flag at the time of non-operation is " 0 ", the regeneration is not continued.

When it is determined in step S11 that the actuators are not operated, the process proceeds to step S13 where the devices constituting the regenerative device, for example, the motor generator 91, the inverter 92, the capacitors 26, An abnormality of the temperature sensor 26a and the tilting angle controller 38 of the regenerative motor 88 is detected and it is judged whether or not it is possible to regenerate normally.

If it is determined in step S13 that the device constituting the regenerative apparatus is abnormal and regeneration can not normally be executed, the process proceeds to step S14. In step S14, the same control as in step S12 is executed.

When it is determined in step S13 that there is no abnormality in the apparatus constituting the regenerative apparatus and regeneration can be normally executed, the flow proceeds to step S15. In step S15, it is determined whether or not the voltage value Vc representing the charged amount of the capacitor 26 is equal to or higher than the regeneration stop voltage Vmax as the second predetermined amount.

Here, the regenerative stop voltage Vmax is set to a value lower than the upper limit voltage Vmax0 for use of the capacitor 26, as shown in Fig. The regenerative stop voltage Vmax may be equal to the voltage at which the regenerative stop is stopped when the regenerative braking control or the boom regenerative braking control is performed. However, in this case, when the voltage of the capacitor 26 becomes the regenerative stop voltage Vmax, when the swing regenerative control or the boom regenerative control is performed, the regenerative energy is not regenerated and the energy of the operating oil can not be recovered. There is a possibility that the system efficiency of the system becomes low. For this reason, it is preferable that the regenerative stop voltage Vmax is set to a value lower than the voltage at which the regeneration is stopped when performing the swing regeneration control or the boom regeneration control. When the voltage of the capacitor 26 is predicted to be increased to some extent when the energy of the operating oil is regenerated by the execution of the swing regeneration control or the boom regeneration control, The regeneration stop voltage Vmax may be appropriately changed by predicting the increase of the voltage of the regenerative stopping voltage Vmax.

If it is determined in step S15 that the voltage value Vc of the capacitor 26 is equal to or larger than the regenerative stop voltage Vmax, the process proceeds to step 16. In step 16, when the regeneration by the regeneration control during non-operation is already executed, the regeneration is stopped, and the regeneration flag at the time of non-operation is set to " 0 ". In the case where the regeneration by the regenerative control at the time of non-operation is not executed, that is, when the regeneration flag at the time of non-operation is "0", the voltage value Vc of the capacitor 26 is high and the regeneration control at the non- Since there is no necessity, the state in which regeneration is not performed is continued.

If it is determined in step S15 that the voltage value Vc of the capacitor 26 is less than the regenerative stop voltage Vmax, the routine proceeds to step 17. In step S17, it is determined whether the voltage value Vc of the capacitor 26 is equal to or lower than the regeneration start voltage Vmin as the first predetermined amount.

Here, the regeneration start voltage Vmin is set to a value higher than the lower limit voltage Vmin0 of the use of the capacitor 26, as shown in Fig. In addition, the voltage of the capacitor 26 immediately after stopping the charging is generally lowered by multiplying the internal resistance R (T), which changes according to the internal temperature T of the capacitor 26, by the current I. That is, if the difference between the regenerative stop voltage Vmax and the regenerative starting voltage Vmin is smaller than the value obtained by multiplying the internal resistance R (T) by the current I, the voltage of the capacitor 26 after being charged and becoming the regenerative stop voltage Vmax, The regeneration control is stopped and the regeneration control is started again. To avoid such a phenomenon, the regeneration start voltage Vmin is a value obtained by multiplying the internal resistance R (T), which varies according to the internal temperature T of the capacitor 26, by the current I supplied to the capacitor 26, It is preferable that the voltage value is updated to a value smaller than a voltage value at any time. Since the characteristic of the internal resistance R (T) changes according to the charged amount SOC of the capacitor 26 and the internal temperature T of the capacitor 26, the characteristic of the internal resistance R (T) It is possible to predict how much voltage drop occurs based on the detection values of the temperature sensor 26a and the current sensor.

If it is determined in step S17 that the voltage value Vc of the capacitor 26 is equal to or smaller than the regeneration start voltage Vmin, the routine proceeds to step 18 where regeneration by non-operation regeneration control is started, . Specifically, as described above, the controller 90 energizes the solenoid of the solenoid valve 58 to switch the solenoid valve 58 to the open position, energizes the solenoid of the on-off valve 9, The on-off valve 9 is switched to the closed position. The pilot pressure is zero and the hydraulic angle of the first main pump 71, that is, the discharge amount is set to be zero, since the opening / closing valve 9 is switched to the closed position, Max. The operating fluid discharged from the first main pump 71 is guided to the combined regeneration flow path 46 through the first main pump regenerating flow path 55 and the energy is recovered by the regenerating motor 88. When the voltage value Vc of the capacitor 26 rises to the regenerative stop voltage Vmax after regeneration by non-operation regeneration control is started, regeneration by non-operation regeneration control is stopped in step S15 as described above.

When it is determined in step S17 that the voltage value Vc of the capacitor 26 is larger than the regeneration start voltage Vmin, the routine proceeds to step 19 and it is determined whether or not the regeneration flag at the time of non-operation is "1" It is determined whether or not regenerative braking is being performed.

If it is determined in step S19 that the non-operation regeneration flag is " 1 ", the process proceeds to step 20. If it is determined that the non-operation regeneration flag is not " 1 &

The voltage value Vc of the capacitor 26 is greater than the regeneration start voltage Vmin and is less than the regeneration stop voltage Vmax. Further, since the regeneration flag at the time of non-operation is " 1 ", regeneration by non-operation regeneration control is being executed. That is, the capacitor 26 is being charged along the arrow A in Fig. 3 by the regeneration control during non-operation. For this reason, regeneration is continued at step 20, and the regeneration flag at the time of non-operation is kept at "1".

On the other hand, when proceeding to step 21, the voltage value Vc of the capacitor 26 is larger than the regeneration start voltage Vmin and less than the regenerative stop voltage Vmax, but the regeneration flag at the time of non-operation is not "1" The regeneration by the regenerative control during non-operation is not executed. In other words, since the capacitor 26 is in the region indicated by B in Fig. 3 and it is not necessary to execute regenerative control at the time of non-operation yet, the regenerative flag at the time of non-operation is kept at "0" . This situation can occur, for example, when the voltage value Vc of the capacitor 26 at the end of regeneration by the regenerative braking control or the boom regeneration control is greater than the regeneration start voltage Vmin and less than the regenerative stop voltage Vmax .

Thus, by performing the regeneration control during the non-operation, the voltage value Vc of the capacitor 26 while the actuators are not operated is greater than the use upper limit voltage Vmax0 from the regeneration start voltage Vmin sufficiently higher than the use lower limit voltage Vmin0 Is held within a certain range up to the low regenerative stop voltage Vmax. Therefore, even when the assist control is executed, the voltage value Vc of the capacitor 26 falls to the lower limit voltage Vmin0, and the capacitor 26 is prevented from becoming an overdischarged state, and the swing regeneration control and the boom regeneration control are executed The voltage value Vc of the capacitor 26 rises up to the use upper limit voltage Vmax0 to prevent the capacitor 26 from becoming overcharged. If the regeneration stop voltage Vmax is set to a value lower than the voltage at which regeneration is stopped when the regenerative braking control or the regenerative braking control is performed, the energy of the operating oil can be sufficiently recovered when the regenerative braking control or the boom regeneration control is performed , The system efficiency of the hybrid construction machine can be improved.

According to the above embodiment, the following effects are produced.

In the control system 100 of the hybrid construction machine, when the voltage value Vc of the capacitor 26 when each actuator is not operated is smaller than the regeneration start voltage Vmin, the first and second And the hydraulic oil is supplied to the regenerative motor 88 from the main pumps 71 and 72. [ Therefore, even if the time when each actuator is not operated is short, the voltage of the capacitor 26 can be raised quickly. As a result, it is possible to prevent the capacitor 26 from becoming an overdischarged state, and to improve the durability of the capacitor 26.

Next, a modified example of the above embodiment will be described.

In the above embodiment, the solenoid valves 58 and 59 and the open / close valves 9 and 21 operated when performing the regeneration control at the time of non-operation are directly controlled by the controller 90. Instead, the solenoid valves 58 and 59 and the open / close valves 9 and 21 are changed to a valve body of a type in which the pilot pressure is supplied to open and close, and a single solenoid valve for supplying the pilot pressure is separately installed And the controller 90 controls the supply of the pilot pressure by the solenoid valve.

In the above embodiment, it is determined whether or not the voltage value Vc of the capacitor 26 is the charged amount of the capacitor 26 and the non-operation regenerative control is executed based on the voltage value Vc. Alternatively, it may be determined whether or not the charge rate (SOC, State Of Charge) of the capacitor 26 is the charge amount of the capacitor 26 and whether or not the non-operation regenerative control is executed based on the charge rate.

In the embodiment described above, the operating oil discharged from the first and second main pumps 71 and 72 is supplied to the first and second main pump regeneration flow paths 55 and 56 through the electromagnetic valves 58 and 59 And is supplied to the regenerative motor 88 via the regenerative motor 88. 4, a flow path is formed in the operation valve 4 for the boom second-speed for communicating the parallel flow path 8 and the first main pump regeneration flow path 55, The hydraulic fluid discharged from the first main pump 71 may be supplied to the regenerative motor 88 by switching the valve 4. [

4, when the pilot pressure source PP is supplied to the pilot chamber 4a through the solenoid valve 58a, the operation valve 4 for the boom second speed is branched from the branch passage 8a branched from the parallel passage 8 The first main pump regeneration flow path 55 is communicated with the first main pump regeneration flow path 55. As described above, the control system 100 of the hybrid construction machine can be made compact by using the existing operation valves 2 to 6 and 14 to 17. In Fig. 4, the flow paths at the other switching positions of the boom second-speed operation valve 4 are omitted

The configuration, action, and effect of the embodiment of the present invention will be summarized below.

The control system 100 of the hybrid construction machine includes first and second main pumps 71 and 72 of variable capacity type for supplying a working fluid to an actuator and hydraulic oil or first and second main pumps A motor generator 91 connected to the regenerative motor 88 and a capacitor 26 for collecting electric power generated by the motor generator 91. The regenerative motor 88, An assist pump 89 which is connected to the regenerative motor 88 and the motor generator 91 and is capable of supplying operating oil to the actuator and a hydraulic pump 88 for supplying hydraulic oil from the first and second main pumps 71 and 72 to the regenerative motor 88 When the controller 90 determines that the voltage of the capacitor 26 is lower than the regeneration start voltage Vmin when the actuator is not in operation, the controller 90 controls the first and second The main pumps 71 and 72 are connected to the regenerative motor 88 The first and second main pumps 71 and 72 are controlled so that the flow rate of the supplied hydraulic fluid is equal to or greater than the flow rate of the hydraulic fluid discharged from the first and second main pumps 71 and 72 when the actuator is operating.

 In this configuration, when the voltage value Vc of the capacitor 26 when each actuator is not operated is smaller than the regeneration start voltage Vmin, the first and second main pumps 71 and 72 are supplied to the regenerative motor 88 The first and second main pumps 71 and 72 are controlled so that the flow rate of the operating fluid is equal to or greater than the flow rate of the operating fluid discharged from the first and second main pumps 71 and 72 when the actuator is operating. Since the relatively large flow rate of hydraulic oil is supplied to the regenerative motor 88, the voltage of the capacitor 26 can be rapidly increased even if the time when each actuator is not operated is short. As a result, since the voltage of the capacitor 26 when the actuators are not operated is kept higher than the regeneration start voltage Vmin and the capacitor 26 is suppressed from becoming an overdischarge state, Durability can be improved.

When the controller 90 determines that the voltage of the capacitor 26 is smaller than the regeneration start voltage Vmin and the voltage of the capacitor 26 is greater than the regeneration start voltage Vmin, The flow rate of the operating fluid supplied from the first and second main pumps 71 and 72 to the regenerative motor 88 is controlled by the first and second main pumps 71 and 72 The first and second main pumps 71 and 72 are controlled such that the flow rate of the hydraulic fluid is equal to or greater than the flow rate of the hydraulic fluid discharged from the first and second main pumps 71 and 72, respectively.

In this configuration, from the first and second main pumps 71 and 72 until the voltage of the capacitor 26 reaches the regenerative stop voltage Vmax after it is determined that the voltage of the capacitor 26 is smaller than the regeneration start voltage Vmin A relatively large flow rate of hydraulic fluid is supplied to the regenerative motor 88. That is, while charging the capacitor 26 when the actuator is not operating, a state in which a relatively large flow rate of hydraulic fluid is supplied to the regenerative motor 88 continues. Therefore, even if the time when each actuator is not operated is short, the voltage of the capacitor 26 can be raised quickly. As a result, since the voltage of the capacitor 26 when the actuators are not operated is kept higher than the regeneration start voltage Vmin and the capacitor 26 is suppressed from becoming an overdischarge state, Durability can be improved.

The regenerative starting voltage Vmin is a value smaller than the value obtained by multiplying the internal resistance R (T), which changes according to the internal temperature T of the capacitor 26, by the current I supplied to the capacitor 26, from the regenerative stop voltage Vmax Value.

In this configuration, the regenerative starting voltage Vmin is set to a value smaller than the value obtained by multiplying the internal resistance R (T) of the capacitor 26 by the current I supplied to the capacitor 26, from the regenerative stop voltage Vmax. Therefore, even if the voltage of the capacitor 26 immediately after stopping the charging drops according to the internal resistance R (T) of the capacitor 26, the regeneration control is stopped and the regeneration control is prevented from being started again . The difference between the regeneration start voltage Vmin and the regenerative stop voltage Vmax is set to be as small as possible while taking the internal resistance R (T) of the capacitor 26 into consideration, so that the regeneration control when the actuators are not operated is shortened It is easy to keep the voltage of the capacitor 26 within a certain range.

The controller 90 determines the failure of the apparatus constituting the control system 100. When the failure is determined, the controller 90 does not charge the capacitor 26 when the actuator is not operating.

In this configuration, when the failure of the apparatus constituting the control system 100 is determined, the charging to the capacitor 26 is stopped. In this way, when any abnormality occurs in the apparatus constituting the control system 100, the charging to the capacitor 26 is stopped, so that the safety of the control system 100 can be secured.

The variable displacement first and second main pumps 71 and 72 for supplying the hydraulic fluid to the actuator and the hydraulic oil supplied from the hydraulic fluid circulated from the actuator or the first and second main pumps 71 and 72 A regenerative motor 88 that is rotationally driven, a motor generator 91 connected to the regenerative motor 88, a capacitor 26 that collects the power generated by the motor generator 91, a regenerative motor 88, The control method for controlling the hybrid construction machine having the assist pump (89) connected to the actuator (91) and capable of supplying the hydraulic fluid to the actuator detects the operating state of the actuator and detects the voltage of the capacitor (26) The flow rate of the operating fluid supplied from the first and second main pumps 71 and 72 to the regenerative motor 88 is set to be smaller than the regenerative starting voltage Vmin when the actuator is not operating and the detected voltage of the capacitor 26 is smaller than the regeneration start voltage Vmin , The actuator The flow rate of the hydraulic fluid discharged from the first and second main pumps 71 and 72 is set to be equal to or greater than the flow rate of the hydraulic fluid.

In this control method, when the voltage value Vc of the capacitor 26 when each actuator is not operated is smaller than the regeneration start voltage Vmin, the first and second main pumps 71 and 72 supply the regenerative electric power to the regenerative motor 88 The first and second main pumps 71 and 72 are controlled so that the flow rate of the supplied hydraulic oil becomes equal to or greater than the flow rate of the hydraulic oil discharged from the first and second main pumps 71 and 72 while the actuator is operating. Since the relatively large flow rate of hydraulic oil is supplied to the regenerative motor 88, the voltage of the capacitor 26 can be rapidly increased even if the time when each actuator is not operated is short. As a result, since the voltage of the capacitor 26 when the actuators are not operated is kept higher than the regeneration start voltage Vmin and the capacitor 26 is suppressed from becoming an overdischarge state, Durability can be improved.

Although the embodiments of the present invention have been described above, the above embodiments are only illustrative of some of the application examples of the present invention, and the technical scope of the present invention is not limited to the specific configurations of the above embodiments.

The present application claims priority based on Japanese Patent Application No. 2016-182114 filed on September 16, 2016, the entire contents of which are incorporated herein by reference.

Claims (5)

A control system for a hybrid construction machine,
A variable displacement fluid pressure pump for supplying a working fluid to the fluid pressure actuator,
A regenerative motor rotationally driven by a working fluid being refluxed from the fluid pressure actuator or a working fluid supplied from the fluid pressure pump,
A rotating electric machine connected to the regenerative motor,
A power storage unit for collecting electric power generated by the rotating electric machine,
And a control unit for controlling supply of working fluid from the fluid pressure pump to the regenerative motor,
Wherein when the fluid pressure actuator determines that the charge amount of the power storage unit is smaller than the first predetermined amount when the fluid pressure actuator is not operating, the flow rate of the working fluid supplied from the fluid pressure pump to the regeneration motor And controls the fluid pressure pump to be equal to or greater than a flow rate of the working fluid discharged from the fluid pressure pump when the pressure actuator is in operation. The method according to claim 1,
The control unit determines that the charged amount of the power storage unit has reached a second predetermined amount larger than the first predetermined amount after it is determined that the charged amount of the power storage unit is smaller than the first predetermined amount when the fluid pressure actuator is not operating The control unit controls the fluid pressure pump so that the flow rate of the working fluid supplied to the regenerative motor from the fluid pressure pump becomes equal to or greater than the flow rate of the working fluid discharged from the fluid pressure pump when the fluid pressure actuator is operating The control system of a hybrid construction machine. 3. The method of claim 2,
Wherein the first predetermined amount and the second predetermined amount are voltages,
Wherein the first predetermined amount is a value smaller than a value obtained by multiplying an internal resistance which varies according to an internal temperature of the power storage unit by a current supplied to the power storage unit minus the second predetermined amount. The method according to claim 1,
Wherein the control unit judges a failure of the apparatus constituting the control system and, when the failure is determined, does not charge the storage unit when the fluid pressure actuator is not operating, . A regenerative motor rotatably driven by a working fluid which is refluxed from the fluid pressure actuator or a working fluid supplied from the fluid pressure pump; 1. A control method for controlling a hybrid construction machine comprising a rotary electric machine connected to a rotary electric machine and a power storage unit for collecting electric power generated by the rotary electric machine,
Detecting an operating state of the fluid pressure actuator and detecting a charged amount of the power storage unit,
When the fluid pressure actuator is not operating and the detected amount of charge of the power storage unit is smaller than the first predetermined amount, the flow rate of the working fluid supplied from the fluid pressure pump to the regenerative motor is controlled by the fluid pressure actuator Wherein the flow rate of the working fluid discharged from the fluid pressure pump is equal to or greater than the flow rate of the working fluid discharged from the fluid pressure pump.

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