JP2012193551A - Controller for hybrid construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a stopping processing of a hybrid construction machine after turning an ignition key off.SOLUTION: This controller for the hybrid construction machine includes an internal power supply 260 for supplying power to a CPU 250, a first power supply line 210 and a second power supply line 230 for independently supplying power to the internal power supply 260, a switch 211 provided in the first power supply line 210 and adapted to be on/off when starting/stopping the hybrid construction machine, a voltage monitoring line 220 for inputting a voltage value for the first power supply line 210 to the CPU 250, and a semiconductor switch 232 provided in the second power supply line 230 and adapted to be controlled to be on/off by the CPU 250. The CPU 250 determines the on/off state of the switch 211 based on the voltage value for the first power supply line 210, and turns the semiconductor switch 232 on when determining that the switch 211 is on and also turns the semiconductor switch 232 on after determining that the switch 211 is off.

Description

  The present invention relates to a control controller for a hybrid construction machine.

  Patent Document 1 discloses a so-called hybrid construction machine control system that converts hydraulic energy of a working fluid discharged from a hydraulic actuator into electrical energy or kinetic energy.

JP 2002-275945 A

  In such a hybrid construction machine control system, if the system is stopped simultaneously with the ignition key being turned off, the system may be stopped while the hydraulic energy is high. Therefore, after turning off the ignition key and stopping the hybrid construction machine, hydraulic energy may be converted into electrical energy or kinetic energy.

  The present invention has been made to solve such problems, and performs a system stop process after turning off the ignition key so that hydraulic energy is not converted into electric energy or kinetic energy. The purpose is to be able to.

  The present invention is a control controller for a hybrid construction machine, comprising a CPU, an internal power supply for supplying power to the CPU, a first power supply line for independently supplying power from a battery to the internal power supply, 2 power lines, and provided in the first power line, are turned on when the hybrid construction machine is started to electrically connect the battery and the internal power source, and are turned off when the hybrid construction machine is stopped and the battery A first switch that electrically cuts off the internal power supply, a voltage monitoring line that inputs a voltage value of the first power supply line closer to the internal power supply than the first switch to the CPU, and the second power supply A second switch is provided on the line and is ON / OFF controlled by the CPU to electrically connect or disconnect the battery and the internal power source. And the CPU determines an ON / OFF state of the first switch based on a voltage value of the first power supply line, and determines the second switch when the first switch is determined to be ON. The second switch is turned on even after it is determined that the first switch is turned off.

  According to the present invention, power is supplied to the internal power supply serving as the power source of the CPU from the two independent power supply lines, so that the power can be supplied to the CPU even after the hybrid construction machine is stopped. . Therefore, after the hybrid construction machine is stopped, various types of stop processing can be performed on the hybrid construction machine.

It is a schematic side view of the excavation attachment of a hydraulic excavator. It is a schematic block diagram of the fluid pressure control apparatus by one Embodiment of this invention. It is a schematic block diagram of the assist regeneration mechanism connected to the fluid pressure control apparatus by one Embodiment of this invention. It is a schematic block diagram of the power supply circuit of the controller by one Embodiment of this invention. It is a flowchart explaining the stop process by one Embodiment of this invention.

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

  The fluid pressure control device controls the operation of a hydraulic working device such as a hydraulic excavator. In this embodiment, the fluid pressure control device controls the expansion / contraction operation of the boom cylinder 104 that drives the boom (load) 101 of the hydraulic excavator shown in FIG. The case where it does is demonstrated.

  FIG. 1 is a schematic side view of a excavator attachment 100 of a hydraulic excavator.

  The excavation attachment 100 includes a boom 101, an arm 102, and a bucket 103 for performing excavation work and the like, and these are driven by a boom cylinder 104, an arm cylinder 105, and a bucket cylinder 106, which are actuators. Each of the boom cylinder 104, the arm cylinder 105, and the bucket cylinder 106 is a hydraulic cylinder.

  FIG. 2 is a schematic configuration diagram of the fluid pressure control device 120 according to the present embodiment.

  The fluid pressure control device 120 includes a main pump 108, a pilot pump 109, a main control valve 110, a main passage 111, a first passage 112, a second passage 113, and a controller 114.

  The boom cylinder 104 is partitioned into a rod-side pressure chamber 104a and a bottom-side pressure chamber 104b by a piston rod 107 that slidably moves within the boom cylinder 104. The piston rod 107 is connected to the boom 101, and the boom 101 is driven when the piston rod 107 moves in the boom cylinder 104.

  The main pump 108 and the pilot pump 109, which are hydraulic sources, are driven by an engine (not shown) mounted on a hydraulic excavator and discharge hydraulic oil (working fluid). The main pump 108 and the pilot pump 109 are variable displacement hydraulic pumps capable of controlling the discharge amount of hydraulic oil by controlling the inclination angle of the swash plate. The engine is operated at a predetermined rotational speed and load with good operating efficiency.

  The hydraulic oil discharged from the main pump 108 is supplied to a main control valve (control valve) 110 that switches between supplying and discharging hydraulic oil to and from the boom cylinder 104. The main pump 108 and the main control valve 110 are connected by a main passage 111. In addition to the hydraulic oil discharged from the main pump 108, the hydraulic oil discharged from the assist pump 3 of the assist regeneration mechanism 10 (see FIG. 3), which will be described later, is guided to the main passage 111 through the sub passage 31.

  The main control valve 110 and the rod side pressure chamber 104a of the boom cylinder 104 are connected by a first passage 112, and the main control valve 110 and the bottom side pressure chamber 104b of the boom cylinder 104 are connected by a second passage 113. . Connected to the second passage 113 is a return passage 21 through which hydraulic oil discharged from the bottom pressure chamber 104b of the boom cylinder 104 flows to drive the regeneration motor 2 of the assist regeneration mechanism 10 (see FIG. 3) described later. The

  The main control valve 110 is operated by a pilot pressure supplied from the pilot pump 109 to the pilot chambers 110a and 110b. Control of the pilot pressure supplied to the pilot chambers 110a and 110b is performed by the controller 114 controlling the pilot solenoid valve 115 based on a lever operation by the crew of the excavator.

  When the pilot pressure is supplied to the pilot chamber 110a, the main control valve 110 is switched to the position a, the hydraulic oil is supplied from the main pump 108 to the rod side pressure chamber 104a via the first passage 112, and the bottom The hydraulic oil in the side pressure chamber 104 b is discharged to the tank T through the second passage 113. As a result, the piston rod 107 in the boom cylinder 104 moves downward in FIG. 2, that is, the boom cylinder 104 contracts, and the boom 101 descends in the direction of the arrow 121 shown in FIG.

  When the pilot pressure is supplied to the pilot chamber 110b, the main control valve 110 is switched to the position b, and hydraulic oil is supplied from the main pump 108 to the bottom pressure chamber 104b via the second passage 113. The hydraulic oil in the rod side pressure chamber 104 a is discharged to the tank T through the first passage 112. As a result, the piston rod 107 in the boom cylinder 104 moves upward in FIG. 2, that is, the boom cylinder 104 extends, and the boom 101 rises in the direction of the arrow 122 shown in FIG.

  Further, when the pilot pressure is not supplied to the pilot chambers 110a and 110b, the main control valve 110 is switched to the position c, the supply and discharge of the hydraulic oil to the boom cylinder 104 is shut off, and the boom 101 is kept stopped.

  Thus, the main control valve 110 has three switching positions: a contracted position “a” for contracting the boom cylinder 104, an extended position “b” for extending the boom cylinder 104, and a blocking position “c” for holding the load of the boom cylinder 104.

  Here, when the main control valve 110 is switched to the shut-off position c to stop the movement of the boom 101, the piston rod 107 in the boom cylinder 104 is placed on the lower side of FIG. A force for moving the boom cylinder 104, that is, a force for contracting the boom cylinder 104 is applied. Thus, in the boom cylinder 104 that drives the boom 101, the bottom-side pressure chamber 104b is a load-side pressure chamber in which the load pressure acts when the main control valve 110 is in the shut-off position c. On the other hand, in the arm cylinder 105 that drives the arm 102, the rod side pressure chamber 104a is a load side pressure chamber.

  In the following description, a decrease in load means a change in the direction in which the volume of the load side pressure chamber decreases, and an increase in load means a change in the direction in which the volume of the load side pressure chamber increases. Point to. Therefore, in the case of the boom cylinder 104, the decrease in load means that the boom cylinder 104 contracts and the boom 101 descends, and the increase in load means that the boom cylinder 104 extends and the boom 101 rises. Point to.

  In the present embodiment, the fluid pressure control device 120 regenerates the hydraulic energy of the hydraulic oil discharged from the bottom-side pressure chamber 104b as electric energy as necessary when the boom cylinder 104 is contracted, and the boom cylinder. An assist regenerative mechanism 10 that can perform an assist that provides an assisting force as necessary when extending 104 is connected. In this way, a hydraulic work device such as a hydraulic excavator, in which the operation of the actuator is controlled by the fluid pressure control device 120 including the assist regeneration mechanism 10, is referred to as a hybrid construction machine.

  FIG. 3 is a schematic configuration diagram of the assist regeneration mechanism 10 connected to the fluid pressure control device 120.

  The assist regeneration mechanism 10 includes a motor generator 1, a regeneration motor 2, an assist pump 3, a battery 4, an inverter 5, a return passage 21, and a sub passage 31.

  The motor generator 1 has a function as an electric motor driven by the battery 4 to drive the assist pump 3 and a function as an electric generator driven by the regenerative motor 2 to generate electric power. The rotation shafts of the motor generator 1, the regenerative motor 2 and the assist pump 3 are arranged coaxially. When the rotation shaft of the motor generator 1 rotates, the rotation shafts of the regenerative motor 2 and the assist pump 3 rotate together. To do. Similarly, when the rotating shaft of the regenerative motor 2 rotates, the rotating shafts of the motor generator 1 and the assist pump 3 rotate together.

  The regenerative motor 2 is a variable displacement hydraulic motor that can control the output torque by controlling the inclination angle of the swash plate. The regenerative motor 2 is driven by the hydraulic oil discharged from the bottom pressure chamber 104b of the boom cylinder 104 and flowing through the return passage 21. Control of the tilt angle of the swash plate of the regenerative motor 2 is performed by the controller 114 controlling the tilt angle controller 24. By controlling the inclination angle of the swash plate of the regenerative motor 2, the capacity of the regenerative motor 2 changes, and the maximum value of torque that can be generated by the regenerative motor 2 (hereinafter referred to as "maximum motor torque") changes.

  The return passage 21 is provided with a return control valve 22 that switches between supply and discharge of hydraulic fluid to the regenerative motor 2. The return control valve 22 has a communication position d for supplying hydraulic oil to the regenerative motor 2 according to the pilot pressure supplied from the pilot pump 109 to the pilot chamber 22a, and a shut-off for stopping the supply of hydraulic oil to the regenerative motor 2. Switch to position e. Control of the pilot pressure supplied to the pilot chamber 22a is performed by the controller 114 controlling the pilot solenoid valve 23 based on a lever operation by the crew of the excavator.

  The assist pump 3 is a variable displacement hydraulic pump capable of controlling the discharge amount by controlling the inclination angle of the swash plate. The assist pump 3 is driven by the motor generator 1 and supplies hydraulic oil to the main passage 111 via the sub passage 31. Control of the tilt angle of the swash plate of the assist pump 3 is performed by the controller 114 controlling the tilt angle controller 34. By controlling the inclination angle of the swash plate of the assist pump 3, the capacity of the assist pump 3 changes, and the maximum value of the flow rate of hydraulic oil that can be discharged by the assist pump 3 (hereinafter referred to as "maximum discharge amount") changes. .

  The sub passage 31 is provided with a sub control valve 32 that switches supply and discharge of hydraulic oil to and from the main passage 111. The sub control valve 32 has a communication position f for supplying hydraulic oil to the main passage 111 according to the pilot pressure supplied from the pilot pump 109 to the pilot chamber 32a, and a cutoff for stopping the supply of hydraulic oil to the main passage 111. Switch to position g. Control of the pilot pressure supplied to the pilot chamber 32a is performed by the controller 114 controlling the pilot solenoid valve 33 based on a lever operation by the crew of the excavator.

  The motor generator 1 is connected to a battery 4 serving as a power source via an inverter 5.

  The battery 4 is configured by connecting a plurality of secondary batteries such as chargeable / dischargeable lithium-ion batteries in series. The power line 41 of the battery 4 and the inverter 5 is provided with a relay 42 for cutting off the electrical connection. The relay 42 is turned on and off by the controller 114.

  The inverter 5 includes a current conversion unit 51 and a smoothing capacitor 52.

  The current conversion unit 51 includes a plurality of semiconductor switches 511 such as an IGBT (Insulated Gate Bipolar Transistor). The semiconductor switch 511 of the current conversion unit 51 is controlled to be opened and closed by the controller 114, thereby converting direct current into alternating current or alternating current into direct current. Specifically, when the motor generator 1 is caused to function as an electric motor, the direct current from the battery 4 is converted into a three-phase alternating current of an arbitrary frequency by the current conversion unit 51 and supplied to the motor generator 1. On the other hand, when the motor generator 1 is caused to function as a generator, the current converter 51 converts the three-phase alternating current from the motor generator 1 into direct current and supplies the direct current to the battery 4.

  The smoothing capacitor 52 is provided in parallel with the current converter 51 and on the battery 4 side with respect to the current converter 51. The smoothing capacitor 52 is repeatedly charged and discharged during the operation of the motor generator 1 to smooth the direct current.

  Next, the operation of the fluid pressure control device 120 according to the present embodiment will be described with reference to FIGS. 2 and 3.

  First, regeneration by the assist regeneration mechanism 10 performed as necessary when the load is lowered will be described.

  When a lever operation for contracting the boom cylinder 104 is performed by the crew of the hydraulic excavator, the main control valve 110 is switched to the contracted position a, and hydraulic oil is supplied to the rod side pressure chamber 104a and from the bottom side pressure chamber 104b. Hydraulic oil is discharged.

  At this time, when the return control valve 22 is switched to the communication position d as necessary, for example, when the battery charge amount of the battery 4 is relatively low, a part of the hydraulic oil discharged from the bottom side pressure chamber 104b is obtained. It is supplied to the regenerative motor 2 via the return passage 21. At the same time, the inclination angle of the swash plate is controlled so that the discharge amount from the assist pump 3 is minimized.

  Thereby, since the rotating shaft of the motor generator 1 rotates in synchronization with the rotating shaft of the regenerative motor 2, the motor generator 1 can generate electric power, and the battery 4 can be charged. That is, the hydraulic energy of the working fluid discharged from the boom cylinder 104 can be converted into electric energy.

  On the other hand, for example, when the battery charge amount of the battery 4 is relatively high, when the return control valve 22 is switched to the shut-off position e as necessary, all the hydraulic oil discharged from the bottom side pressure chamber 104b is second. It is discharged to the tank T through the passage 113, and regeneration is stopped.

  Next, assist by the assist regeneration mechanism 10 that is performed as necessary when the load increases will be described.

  When a lever operation for extending the boom cylinder 104 is performed by a crew member of the hydraulic excavator, the main control valve 110 is switched to the extended position b, the working oil is supplied to the bottom side pressure chamber 104b, and the rod side pressure chamber 104a The hydraulic oil is discharged to the tank T through the first passage 112.

  Here, the engine is operated at a predetermined rotational speed and load with good operating efficiency. Therefore, when it is desired to quickly extend the boom cylinder 104, the flow rate of hydraulic oil supplied to the bottom pressure chamber 104b may be insufficient with only the discharge amount by the driving force of the engine. In such a case, the assist regeneration mechanism 10 assists.

  Specifically, the battery generator 4 drives the motor generator 1 as an electric motor to drive the assist pump 3. Thereby, hydraulic fluid is discharged from the assist pump 3. As a result, the hydraulic oil discharged from the assist pump 3 can be joined to the main passage 111 via the sub passage 31 and an auxiliary force can be applied when the boom cylinder 104 is extended.

  Here, in the case of the fluid pressure control device 120 including the assist regeneration mechanism 10, if the ignition key 116 is turned off by the crew of the hydraulic excavator and the controller 114 is turned off at the same time, the following problem occurs. The ignition key 116 is turned on when the hydraulic excavator is started and turned off when the hydraulic excavator is stopped.

  When the ignition key 116 is turned off, the engine is stopped and the main pump 108 and the pilot pump 109 are stopped.

  At this time, when the ignition key 116 is turned off and the controller 114 is turned off at the same time, the output torque of the regenerative motor 2 is minimized, and the discharge flow rate of the assist pump 3 is minimized. It is stopped without controlling the swash plate.

  Further, the power supply to the pilot solenoid valves 23 and 33 is stopped, and the return control valve 22 and the sub control valve 32 are switched to the cutoff positions e and g.

  Then, after the ignition key 116 is turned off, the regenerative motor 2 is rotated by the hydraulic energy of the hydraulic oil existing on the downstream side of the return control valve 22, and a situation in which the hydraulic oil can be discharged from the assist pump 3 occurs. . As a result, the pressure in the sub passage 31 becomes high, and when the ignition key 116 is turned on next time and the sub control valve 32 is switched to the communication position f, the high-pressure hydraulic oil is supplied to the bottom side pressure chamber 104b of the boom cylinder 104. May cause a shock. Moreover, since the load applied to the assist pump 3 is increased due to the increase in the pressure of the sub-passage 31, there is a possibility that the assist pump 3 is rapidly deteriorated.

  Further, although the electric charge is accumulated in the smoothing capacitor 52 of the inverter 5 during the operation of the motor generator 1, it is not preferable to leave the electric charge accumulated. That is, it is preferable to perform a discharge process for discharging the electric charge of the smoothing capacitor 52 after the ignition key 116 is turned off. However, if the controller 114 is turned off at the same time as the ignition key 116 is turned off, the discharge process is executed. I can't.

  Thus, in the hybrid construction machine in which the operation of the actuator is controlled by the fluid pressure control device 120 including the assist regeneration mechanism 10, the ignition motor 116 and the swash plate of the assist pump 3 are controlled after turning off the ignition key 116. Then, it is necessary to perform a stop process for discharging the smoothing capacitor 52.

  Therefore, in this embodiment, the power supply circuit 200 of the controller 114 is configured so that stop processing can be performed even after the ignition key 116 is turned off.

  FIG. 4 is a schematic configuration diagram of the power supply circuit 200 of the controller 114 according to the present embodiment.

  The power supply circuit 200 of the controller 114 includes a first power supply line 210, a voltage monitoring line 220, a second power supply line 230, a control line 240, and a CPU 250.

  The first power supply line 210 is a line for supplying power to the CPU 250 when the ignition key 116 is turned on. The first power supply line 210 has one end connected to the battery 4 via an ignition switch 211 that is an example of a first switch, and the other end connected to the internal power supply 260 of the controller 114.

  The first power supply line 210 is provided with two diodes 212 for voltage adjustment. Note that the ignition switch 211 is a switch that is turned on when the ignition key 116 is turned on.

  The voltage monitoring line 220 is a line for detecting the state (ON or OFF) of the ignition key 116. One end of the voltage monitoring line 220 is connected between the ignition switch 211 and the diode 212, and the other end is connected to the input port 251 of the CPU 250.

  The voltage monitoring line 220 is provided with a voltage divider 221 that divides the battery voltage. When the ignition key 116 is ON, a voltage value obtained by dividing the battery voltage by the voltage divider 221 (hereinafter referred to as “starting determination voltage”) is input to the CPU 250. On the other hand, when the ignition key 116 is OFF, a voltage value lower than the start determination voltage (hereinafter referred to as “stop determination voltage”) is input to the CPU 250.

  The second power supply line 230 is a line for supplying power to the CPU 250 after turning off the ignition key 116. The second power supply line 230 has one end connected to the battery 4 and the other end connected to the internal power supply 260 of the controller 114.

  The second power supply line 230 is provided with a diode 231 for voltage adjustment and a transistor (hereinafter referred to as “first semiconductor switch 232”) as an example of a second switch.

  The control line 240 is a line for turning on or off the first semiconductor switch 232. The control line 240 has one end connected to the output port 252 of the CPU 250 and the other end connected to the first semiconductor switch 232.

  The control line 240 includes a voltage divider 241 that divides a voltage signal output from the output port 252 of the CPU 250, and a transistor that turns on by the voltage signal divided by the voltage divider 241 and turns on the first semiconductor switch 232 ( (Hereinafter referred to as “second semiconductor switch 242”).

  The CPU 250 operates by receiving necessary power from the internal power supply 260.

  The CPU 250 determines the state of the ignition key 116 based on the voltage value input to the input port 251. Specifically, if a start determination voltage is input to the input port 251, the CPU 250 determines that the ignition key 116 is ON. On the other hand, if a stop determination voltage is input to the input port 251, the CPU 250 determines that the ignition key 116 is in an OFF state.

  When the CPU 250 determines that the ignition key 116 is in the ON state, the CPU 250 outputs a voltage signal from the output port 252 to turn on the first semiconductor switch 232. As a result, power can be supplied from the second power supply line 230 to the internal power supply 260 in addition to the first power supply line 210, so that the ignition key 116 is turned off and the power supply from the first power supply line 210 is turned off. Even after the power supply is cut off, the power can be supplied to the internal power supply 260 through the second power supply line 230. As a result, the CPU 250 can be operated even after the ignition key 116 is turned off.

  When the CPU 250 determines that the ignition key 116 is in the OFF state, the CPU 250 performs a predetermined stop process and then turns off the first semiconductor switch 232 by stopping the output of the voltage signal from the output port 252. Finally, power supply to the internal power supply 260 is stopped.

  FIG. 5 is a flowchart illustrating the stop process according to the present embodiment that is executed by the controller 114. When the ignition key 116 is turned on and power is supplied to the internal power supply 260 via the first power supply line 210, the controller 114 outputs a voltage signal from the output port 252 of the CPU 250 to switch the first semiconductor switch 232. The power is turned on so that power can be supplied from the second power supply line 230 to the internal power supply 260. As described above, the controller 114 secures the power supply to the internal power supply 260 with the two power supply lines of the first power supply line 210 and the second power supply line 230, and then performs the following routine with a predetermined calculation cycle (for example, 500 In milliseconds).

  In step S <b> 1, the controller 114 determines the state of the ignition key 116 based on the voltage value input to the input port 251 of the CPU 250. If a start determination voltage is input to the input port 251 of the CPU 250, the controller determines that the ignition key 116 is in an ON state, and ends the current process. On the other hand, if the stop determination voltage is input to the input port 251 of the CPU 250, the controller 114 determines that the ignition key 116 is OFF, and performs the process of step S2.

  In step S2, the controller 114 switches the main control valve 110 to the cutoff position c, and switches the return control valve 22 and the sub control valve 32 to the cutoff positions e and g, respectively.

  In step S3, the controller 114 sets the inclination angles of the swash plates of the regenerative motor 2 and the assist pump 3 so that the output torque of the regenerative motor 2 is minimized and the discharge flow rate of the assist pump 3 is minimized. Control. That is, the capacities of the regenerative motor 2 and the assist pump 3 are controlled so that the maximum output torque of the regenerative motor 2 and the maximum discharge amount of the assist pump 3 are minimized.

  Thereby, after turning off the ignition key 116, it is possible to prevent the regenerative motor 2 from being rotated by the hydraulic oil existing on the downstream side of the return control valve 22 and the hydraulic oil from being discharged from the assist pump 3. Therefore, the shock at the next start and the deterioration of the assist pump 3 can be prevented.

  In step S <b> 4, the controller 114 turns off the relay 42 and disconnects the electrical connection between the battery 4 and the inverter 5.

  In step S <b> 5, the controller 114 operates the inverter 5 to discharge the electric charge remaining in the smoothing capacitor 52 to the motor generator 1.

  As a result, after the ignition key 116 is turned off, no charge is accumulated in the smoothing capacitor 52.

  In step S6, the controller 114 determines whether or not the smoothing capacitor 52 has been discharged. The determination of whether or not the discharge has ended includes a method of determining by measuring the terminal voltage of the inverter 5 and a method of determining whether or not a predetermined time has elapsed since the start of discharge. In this embodiment, the predetermined time has elapsed. Sometimes, it is determined that the discharge of the smoothing capacitor 52 has ended. When the controller 114 determines that the discharge of the smoothing capacitor 52 has been completed, the controller 114 performs the process of step S7, and otherwise returns to the process of step S5.

  In step S <b> 7, the controller 114 stops outputting the voltage signal from the output port 252, turns off the first semiconductor switch 232, and turns off the controller 114.

  According to the present embodiment described above, power supply to the internal power supply 260 of the controller 114 is ensured by the two power supply lines of the first power supply line 210 and the second power supply line 230. Therefore, even after the ignition key 116 is turned off, power can be supplied to the internal power supply 260 of the controller 114 via the second power supply line 230.

  Thus, after the ignition key 116 is turned off, the regenerative motor 2 and the assist pump 3 are configured so that the output torque of the regenerative motor 2 is minimized and the discharge flow rate of the assist pump 3 is minimized. The inclination angle of the swash plate can be controlled. That is, after the ignition key 116 is turned off, the capacities of the regenerative motor 2 and the assist pump 3 can be controlled so that the maximum output torque of the regenerative motor 2 and the maximum discharge amount of the assist pump 3 are minimized. it can. Therefore, the regenerative motor 2 is rotated by the hydraulic oil existing on the downstream side of the return control valve 22, and the hydraulic oil can be prevented from being discharged from the assist pump 3, so that the shock at the next start and the deterioration of the assist pump 3 can be prevented. Can be prevented.

  In addition, after the ignition key 116 is turned off, the smoothing capacitor 52 can be discharged by operating the inverter 5. Therefore, it is possible to prevent the charge from being accumulated in the smoothing capacitor 52 from the time when the ignition key 116 is turned off until the time when the ignition key 116 is turned on next time.

  Note that the present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  For example, in the above embodiment, the hydraulic cylinder is described as an example of the actuator. However, the present invention is not limited to this, and a travel motor or a swing motor of a construction machine such as a hydraulic excavator or a work machine may be used.

  In the above embodiment, the assist regeneration mechanism 10 is applied to the fluid pressure control device 120 that drives only the boom cylinder 104 in order to facilitate understanding of the invention. However, the boom cylinder 104, the arm cylinder 105, the bucket cylinder 106, the traveling You may apply to the fluid-pressure control apparatus 120 which drives several actuators, such as a motor and a turning motor.

  In the above embodiment, the capacities of the regenerative motor 2 and the assist pump 3 are minimized so that the maximum output torque of the regenerative motor 2 and the maximum discharge amount of the assist pump 3 are minimized after the ignition key 116 is turned off. However, the present invention is not limited to the one that minimizes the maximum output torque of the regenerative motor 2 and the maximum discharge amount of the assist pump 3. The maximum output torque of the regenerative motor 2 and the maximum discharge amount of the assist pump 3 are smaller than when the ignition key 116 is in an OFF state within a range in which the shock at the next start and the deterioration of the assist pump 3 can be prevented. The capacities of the regenerative motor 2 and the assist pump 3 may be controlled.

DESCRIPTION OF SYMBOLS 1 Motor generator 2 Regenerative motor 3 Assist pump 4 Battery 5 Inverter 52 Smoothing capacitor 108 Main pump 104 Boom cylinder (actuator)
114 controller (control controller)
210 First power line 211 Ignition switch (first switch)
220 Voltage monitoring line 230 Second power supply line 232 Transistor (second switch)
250 CPU
260 Internal power supply S3 to S7 Stop processing

Claims (5)

A controller for a hybrid construction machine,
CPU,
An internal power supply for supplying power to the CPU;
A first power supply line and a second power supply line for independently supplying power from the battery to the internal power supply,
Provided in the first power line, turned on when the hybrid construction machine is started to electrically connect the battery and the internal power source, and turned off when the hybrid construction machine is stopped to turn the battery and the internal power source A first switch that electrically shuts off,
A voltage monitoring line for inputting the voltage value of the first power supply line closer to the internal power supply than the first switch to the CPU;
A second switch provided in the second power supply line, which is ON / OFF controlled by the CPU and electrically connects or disconnects the battery and the internal power supply;
With
The CPU
Based on the voltage value of the first power line, the ON / OFF state of the first switch is determined. When it is determined that the first switch is ON, the second switch is turned ON, and the first switch is turned OFF. Even after determining that the second switch is ON,
A controller for a hybrid construction machine characterized by that. When the CPU determines that the first switch is OFF, the CPU performs a predetermined stop process on the hybrid construction machine, and then turns the second switch OFF.
The control controller of a hybrid construction machine according to claim 1. The hybrid construction machine is
A main pump driven by the engine;
An actuator driven by a working fluid supplied from the main pump;
A regenerative motor driven by the working fluid discharged from the actuator;
A variable displacement assist pump that discharges a working fluid for merging with the working fluid discharged from the main pump;
A motor generator connected to the battery via an inverter, functioning as an electric motor driven by the battery and driving the assist pump, driven by the regenerative motor and functioning as a generator;
With
The stop process is a process of controlling the capacity of the assist pump so that the discharge amount of the assist pump is smaller than the discharge amount when it is determined that the first switch is OFF.
The control controller for a hybrid construction machine according to claim 2, wherein The hybrid construction machine is
A main pump driven by the engine;
An actuator driven by a working fluid supplied from the main pump;
A variable capacity regenerative motor driven by the working fluid discharged from the actuator;
An assist pump that discharges the working fluid for joining the working fluid discharged from the main pump;
A motor generator connected to the battery via an inverter, functioning as an electric motor driven by the battery and driving the assist pump, driven by the regenerative motor and functioning as a generator;
With
The stop process is a process of controlling the capacity of the regenerative motor so that the output torque of the regenerative motor is smaller than the output torque when it is determined that the first switch is OFF.
The control controller for a hybrid construction machine according to claim 2, wherein The hybrid construction machine is
A main pump driven by the engine;
An actuator driven by a working fluid supplied from the main pump;
A regenerative motor driven by the working fluid discharged from the actuator;
An assist pump that discharges the working fluid for joining the working fluid discharged from the main pump;
A motor generator connected to the battery via an inverter, functioning as an electric motor driven by the battery and driving the assist pump, driven by the regenerative motor and functioning as a generator;
With
The stop process is a process of discharging a smoothing capacitor inside the inverter.
The control controller for a hybrid construction machine according to claim 2, wherein

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