JP5639943B2 - Power storage device and hybrid construction machine - Google Patents

Description

  The present invention relates to a power storage device including a plurality of power storage cells and a hybrid construction machine equipped with the power storage device.

  2. Description of the Related Art A hybrid construction machine is known that can charge a regenerative electric power of an engine or mechanical power to a power storage device such as a battery and use the charged electric power for mechanical power.

  The power storage device is provided with a switch for inputting / outputting electric power of the power storage device. Since an inrush current flows when the switch is turned on, it is common to provide a circuit that regulates the inrush current.

  Cited Document 1 discloses an electric device control apparatus that charges a smoothing capacitor from a battery through a current limiting element and a sub-contactor before the main contactor is turned on.

JP-A-9-56167

  In the conventional power storage device, after the inrush current is blocked by the current limiting element and the capacitor by turning on the sub contactor, the main contactor is turned on and the sub contactor is turned off.

  In such a configuration, after the main contactor is turned on, if the main contactor is turned off due to factors such as vibration or impact, power is supplied to an electric device such as an inverter that inputs and outputs power to the power storage device. Disappears and the operation of electrical equipment stops suddenly.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a power storage device and a hybrid construction machine that can safely stop an electric device even when the contactor is abnormal.

A power storage device of the present invention includes a power storage unit that stores power, a first switch and a second switch having a current limiting element, and a switch circuit that interrupts connection between the power storage unit and a load by the first switch and the second switch. A capacitor for smoothing the power input / output to / from the power storage unit, a first voltage detection unit for detecting a voltage on the power storage unit side with respect to the switch circuit, and a second for detecting a voltage on the load side with respect to the switch circuit And a power storage unit control device for a power storage device that controls the switch circuit . The power storage unit control device turns on the first switch when the power input / output to the power storage unit is turned on, and the capacitor voltage and but the second switch is turned on after being charged, even after turning the second switch, which maintains the introduction of the first switch, after the second switch is turned on, is detected by the second voltage detecting unit If difference between the voltage detected by the first voltage detecting unit is generated an error signal, after the stop process of the load is made in accordance with the error signal, characterized by interrupting the first switch .

Further, the hybrid construction machine of the present invention includes a variable displacement pump, an operation valve that controls the flow rate of the discharge oil guided from the variable displacement pump to the actuator, and a regenerative hydraulic pressure that is rotated by the discharge oil of the variable displacement pump. A motor, a generator driven in association with rotation of the hydraulic motor, a power storage device that stores power generated by driving the power generator, an inverter provided between the power generator and the power storage device, and a variable capacity A hybrid construction machine comprising a mold pump , an operation valve, a generator , a power storage device, and a hybrid control device that controls the operation of the inverter , wherein the power storage device includes a power storage unit that stores power and a current limiting element. comprising a first switch and a second switch, a switch circuit for intermittently connecting the power storage unit and the inverter by the first and second switches,蓄A capacitor for smoothing the power input to and output section, the second voltage detecting unit for detecting a first voltage detector for detecting a voltage of the storage unit side of the switch circuit, the voltage on the load side of the switching circuit And a power storage unit control device of the power storage device that controls the switch circuit. The power storage unit control device turns on the first switch when the power input / output to the power storage unit is turned on, and the capacitor is charged. After the second switch is turned on, the first switch is kept turned on even after the second switch is turned on. After the second switch is turned on, the voltage detected by the second voltage detector and the first voltage When there is a difference between the voltage detected by the detection unit, an error signal is output to the hybrid control device, and the hybrid control device performs inverter stop processing according to the error signal, and the power storage unit Control circuit, after the stop process of the inverter is performed, characterized by interrupting the first switch.

According to the present invention, after the second switch is turned on, the first switch is kept turned on. After the second switch is turned on, if an abnormality of the second switch is detected, the load stop process is performed. Shut off the first switch. Thereby, even when there is an abnormality in the second switch, the electric power of the power storage unit can be supplied to the load by the first switch, so that the electric device such as an inverter connected to the power storage device can be safely stopped. Can do.

It is explanatory drawing of the control system of the hybrid construction machine of embodiment of this invention. It is a structure circuit diagram of the electrical storage unit of embodiment of this invention. It is a flowchart of the process which the electrical storage unit control apparatus of embodiment of this invention performs.

  Hereinafter, a control device for a hybrid construction machine according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiment, a case where the hybrid construction machine is a power shovel will be described.

  FIG. 1 is an explanatory diagram of a control system for a hybrid construction machine according to an embodiment of the present invention.

  The power shovel is provided with variable capacity first and second main pumps 71 and 72 driven by an engine 73 as a prime mover. The first and second main pumps 71 and 72 rotate coaxially. The engine 73 is provided with a generator 1 that exhibits the power generation function using the remaining power of the engine 73. The engine 73 is provided with a rotation speed sensor 74 that detects the rotation speed of the engine 73.

  The hydraulic fluid discharged from the first main pump 71 is supplied to the first circuit system 75. The first circuit system 75 includes a control valve 2 that controls the swing motor 76, a control valve 3 that controls an arm cylinder (not shown), and a boom 2 that controls the boom cylinder 77 in conjunction with a control valve 16 described later. It has an operation valve 4 for speed, an operation valve 5 for controlling a preliminary attachment (not shown), and an operation valve 6 for controlling a first traveling motor (not shown) for left running. Each operation valve 2 to 6 controls the operation of each actuator by controlling the flow rate of the discharged oil guided from the first main pump 71 to each actuator.

  The operation valves 2 to 6 and the first main pump 71 are connected through the neutral flow path 7 and the parallel flow path 8 parallel to the neutral flow path 7. A throttle 9 for generating a pilot pressure is provided downstream of the operation valve 6 for the first travel motor in the neutral flow path 7. The throttle 9 generates a high pilot pressure on the upstream side when the flow rate passing therethrough is high and a low pilot pressure when the flow rate passing therethrough is low.

  When all of the operation valves 2 to 6 are in the neutral position or in the vicinity of the neutral position, the neutral flow path 7 allows all or part of the hydraulic oil discharged from the first main pump 71 to be transferred to the tank 94 via the throttle 9. Lead. At this time, since the flow rate passing through the throttle 9 is larger than that during the stroke, 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 fluid does not flow. In this case, there is almost no flow rate passing through the throttle 9, and the pilot pressure becomes zero. However, depending on the operation amount of the operation valves 2 to 6, a part of the hydraulic oil discharged from the first main pump 71 is guided to the actuator, and the rest is guided to the tank from the neutral flow path 7. A pilot pressure corresponding to the flow rate of the hydraulic oil in the neutral flow path 7 is generated. That is, the throttle 9 generates a pilot pressure corresponding to the operation amount of the operation valves 2 to 6.

  A neutral flow path switching electromagnetic valve 10 is provided between the most downstream operating valve 6 and the throttle 9 in the neutral flow path 7. The neutral flow path switching electromagnetic valve 10 has a solenoid connected to the controller 90. The neutral flow path switching electromagnetic valve 10 is set to the fully open position shown in the figure by the action of the spring force of the spring when the solenoid is not excited, and is set to the throttle position against the spring force of the spring when the solenoid is excited. The throttle opening when the neutral flow path switching electromagnetic valve 10 is switched to the throttle position is set smaller than the throttle 9 opening.

  A pilot flow path 11 is connected between the operation valve 6 and the neutral flow path switching electromagnetic valve 10 in the neutral flow path 7. A pressure generated on the upstream side of the throttle 9 is guided to the pilot flow path 11 as a pilot pressure. The pilot flow path 11 is connected to a regulator 12 that controls the tilt angle of the first main pump 71. The regulator 12 controls the displacement angle of the first main pump 71 per revolution by controlling the tilt angle of the first main pump 71 in inverse proportion to the pilot pressure in the pilot flow path 11. That is, the discharge amount of the pump 71 varies according to the pilot pressure.

  In the pilot flow path 11, a pressure reducing valve 80 and a pilot flow path switching electromagnetic valve 81 are provided in parallel. The pilot flow path switching electromagnetic valve 81 is provided in a bypass flow path 82 that bypasses the pressure reducing valve 80. The pilot flow switching electromagnetic valve 81 has a solenoid connected to the controller 90. When the solenoid is not energized, the communication position shown in the figure is set, and the hydraulic oil from the neutral flow path 7 to the pilot flow path 11 bypasses the pressure reducing valve 80. On the other hand, when the solenoid is energized, it is set to the cutoff position, and the neutral flow path 7 communicates with the pilot flow path 11 only through the pressure reducing valve 80.

  The pilot flow path 11 is provided with a first pressure sensor 13 that detects the pressure of the pilot flow path 11. The pressure signal detected by the first pressure sensor 13 is output to the controller 90. Since the pilot pressure in the pilot flow path 11 changes according to the operation amount of the operation valves 2 to 6, the pressure signal detected by the first pressure sensor 13 changes according to the required flow rate of the first circuit system 75.

  The second main pump 72 is connected to the second circuit system 78. The second circuit system 78 includes, in order from the upstream side thereof, an operation valve 14 that controls a second traveling motor (not shown) for right traveling, an operation valve 15 that controls a bucket cylinder (not shown), An operation valve 16 for controlling the boom cylinder 77 and an operation valve 17 for second-arm arm for controlling an arm cylinder (not shown) are provided. The operation valve 16 is provided with a sensor (not shown) that detects an operation direction and an operation amount, and a detection signal of this sensor is output to the controller 90. The operation valves 14 to 17 control the operation of each actuator by controlling the flow rate of the discharged oil guided from the second main pump 72 to each actuator.

  The operation valves 14 to 17 and the second main pump 72 are connected through a neutral flow path 18 and a parallel flow path 19 parallel to the neutral flow path 18. A throttle 20 for generating a pilot pressure is provided on the downstream side of the operation valve 17 in the neutral flow path 18. The throttle 20 has the same function as the throttle 9 on the first main pump 71 side.

  A neutral flow path switching electromagnetic valve 21 is provided between the most downstream operating valve 17 and the throttle 20 in the neutral flow path 18. The neutral flow path switching solenoid valve 21 has the same configuration as the neutral flow path switching solenoid valve 10 on the first main pump 71 side.

  A pilot flow path 22 is connected between the operation valve 17 and the neutral flow path switching electromagnetic valve 21 in the neutral flow path 18. A pressure generated on the upstream side of the throttle 20 is guided to the pilot flow path 22 as a pilot pressure. The pilot flow path 22 is connected to a regulator 23 that controls the tilt angle of the second main pump 72.

  In the pilot flow path 22, a pressure reducing valve 84 and a pilot flow path switching electromagnetic valve 85 are provided in parallel. The pilot flow path switching electromagnetic valve 85 is provided in a bypass flow path 86 that bypasses the pressure reducing valve 84. The pilot flow path 22 is provided with a second pressure sensor 24 that detects the pressure of the pilot flow path 22. The pressure signal detected by the second pressure sensor 24 is output to the controller 90.

  The regulator 23, the pressure reducing valve 84, and the pilot flow path switching electromagnetic valve 85 have the same configuration as the regulator 12, the pressure reducing valve 80, and the pilot flow path switching electromagnetic valve 81 on the first main pump 71 side, and their operations are also the same. Therefore, the description is omitted.

  Flow paths 55 and 56 are connected to the first and second main pumps 71 and 72, respectively, and electromagnetic valves 58 and 59 are provided in the flow paths 55 and 56, respectively. The flow paths 55 and 56 are connected to the first and second main pumps 71 and 72 on the upstream side of the first and second circuit systems 75 and 78. Solenoids of the solenoid valves 58 and 59 are connected to the controller 90. The solenoid valves 58 and 59 are set to the closed position shown when the solenoid is not excited, and are set to the open position when the solenoid is excited.

  The electromagnetic valves 58 and 59 are connected to the hydraulic motor 88 via the junction passage 57 and the check valve 60. The hydraulic motor 88 rotates in conjunction with a motor generator (MG) 91. The electric power generated by the MG 91 is charged to the power storage unit 26 via the inverter 92. The hydraulic motor 88 and the MG 91 may be directly connected or may be connected via a speed reducer.

  The hydraulic oil discharged from the first and second main pumps 71 and 72 is supplied to the hydraulic motor 88 via the electromagnetic valves 58 and 59 to drive the hydraulic motor 88. The hydraulic motor 88 generates electricity by rotating the MG 91 with the driving force. The electric power generated by MG 91 is charged to power storage unit 26 via inverter 92. Thereby, regeneration is performed by the standby flow rate discharged from the first and second main pumps 71 and 72.

  Charging the power storage unit 26 by rotating the hydraulic motor 88 is performed by an operator manually operating and inputting a standby regeneration command signal to the controller 90.

  Note that the battery charger 25 can charge the power storage unit 26 even when connected to a normal household power supply 27. Thus, the battery charger 25 can be connected to an independent power source.

  As described above, the electric power generated by the MG 91 by driving the hydraulic motor 88 with the hydraulic oil discharged from the first and second main pumps 71 and 72 can be charged in the power storage unit 26. Further, the electric power charged in the power storage unit 26 can be used for assisting power of a sub pump 89 described later.

  The actuator port of the operation valve 2 for the swing motor is connected to passages 28 and 29 communicating with the swing motor 76, and brake valves 30 and 31 are connected to the passages 28 and 29, respectively. When the operation valve 2 is maintained at the neutral position, the actuator port is closed and the swing motor 76 maintains the stopped state.

  When the operation valve 2 is switched in one direction from the stop state of the swing motor 76, one passage 28 is connected to the first main pump 71 and the other passage 29 is communicated with the tank 94. As a result, hydraulic oil is supplied from the passage 28 to rotate the turning motor 76, and return oil from the turning motor 76 is returned to the tank 94 through the passage 29. When the operation valve 2 is switched in the opposite direction, the passage 29 is connected to the first main pump 71, the passage 28 communicates with the tank, and the turning motor 76 rotates in the reverse direction.

  When the operation valve 16 is switched from the neutral position to one direction, the hydraulic oil discharged from the second main pump 72 is supplied to the piston side chamber 33 of the boom cylinder 77 through the passage 32 and from the rod side chamber 34. The return oil is returned from the passage 35 to the tank 94 through the operation valve 17 and the neutral flow path switching electromagnetic valve 21, and the boom cylinder 77 extends.

  When the operation valve 16 is switched in the opposite direction, the hydraulic oil discharged from the second main pump 72 is supplied to the rod side chamber 34 of the boom cylinder 77 through the passage 35 and the return oil from the piston side chamber 33 is From the passage 32, it returns to the tank 94 through the operation valve 17 and the neutral flow path switching electromagnetic valve 21, and the boom cylinder 77 contracts. The boom second speed operation valve 3 is switched in conjunction with the operation valve 16. A proportional solenoid valve 36 whose opening degree is controlled by a controller 90 is provided in the passage 32 connecting the piston side chamber 33 of the boom cylinder 77 and the operation valve 16. The proportional solenoid valve 36 maintains the fully open position in the normal state.

  Next, the variable displacement sub-pump 89 that assists the outputs of the first and second main pumps 71 and 72 will be described.

  The sub pump 89 rotates with a driving force when the MG 91 is used as an electric motor, and the hydraulic motor 88 also rotates coaxially with the driving force of the MG 91. The power storage unit 26 is connected to the MG 91 via the inverter 92, and the controller 90 connected to the inverter 92 controls the rotational speed of the MG 91. The tilt angles of the sub pump 89 and the hydraulic motor 88 are controlled by tilt controllers 37 and 38, and the tilt controllers 37 and 38 are controlled by an output signal from the controller 90.

  A discharge passage 39 is connected to the sub pump 89. The discharge passage 39 is formed by branching into a first assist channel 40 that joins the discharge side of the first main pump 71 and a second assist channel 41 that joins the discharge side of the second main pump 72. Each of the first and second assist flow paths 40 and 41 is provided with first and second electromagnetic proportional throttle valves 42 and 43 whose opening degree is controlled by an output signal of the controller 90. Further, in each of the first and second assist flow paths 40 and 41, the hydraulic oil flows from the sub pump 89 to the first and second main pumps 71 and 72 downstream of the first and second electromagnetic proportional throttle valves 42 and 43. Check valves 44 and 45 that allow only these are provided.

  The connection passage 46 is connected to the hydraulic motor 88. The connection passage 46 is connected to the passages 28 and 29 connected to the turning motor 76 via the introduction passage 47 and the check valves 48 and 49. The introduction passage 47 is provided with an electromagnetic switching valve 50 that is controlled to be opened and closed by the controller 90. A pressure sensor 51 is provided between the electromagnetic switching valve 50 and the check valves 48 and 49 to detect the pressure at the time of turning of the turning motor 76 or the pressure at the time of braking. Is output.

  A safety valve 52 that guides hydraulic oil to the connection passage 46 when the pressure in the introduction passage 47 reaches a predetermined pressure is provided downstream of the electromagnetic switching valve 50 in the introduction passage 47. The safety valve 52 is, for example, for maintaining the pressure in the passages 28 and 29 to prevent the turning motor 76 from running away when a failure occurs in the introduction passage 47 system such as the electromagnetic switching valve 50. The connection passage 46 is connected to the tank 94 via the check valve 61.

  Between the boom cylinder 77 and the proportional solenoid valve 36, an introduction passage 53 communicating with the connection passage 46 is provided. The introduction passage 53 is provided with an electromagnetic opening / closing valve 54 whose opening / closing is controlled by the controller 90.

  Next, a case where the assist force of the sub pump 89 is used will be described. The assist flow rate of the sub-pump 89 is set in advance, and the controller 90 determines how to control the tilt angle of the sub-pump 89, the tilt angle of the hydraulic motor 88, the rotational speed of the MG 91, etc. Execute the control.

  When the operation valves 2 to 6 and 14 to 17 of either the first circuit system 75 or the second circuit system 78 are switched, the neutral flow path switching electromagnetic valves 10 and 21 are switched from the throttle position to the open position. As a result, the pilot pressure in the pilot flow paths 11 and 22 is lowered, the lowered pilot pressure is detected by the first and second pressure sensors 13 and 24, and a pilot pressure signal is output to the controller 90.

  The controller 90 switches the electromagnetic valves 58 and 59 to the closed position based on the pilot pressure signals output from the first and second pressure sensors 13 and 24. The first and second main pumps 71 and 72 are displaced by the pilot pressures that are lowered, the displacement volume per revolution is increased by the regulators 12 and 23, and the solenoid valves 58 and 59 are switched to the closed position. 2 The total discharge amount of the main pumps 71 and 72 is supplied to the actuators connected to the first and second circuit systems 75 and 78.

  When the displacement volume per rotation of the first and second main pumps 71 and 72 is increased, the controller 90 keeps the MG 91 rotated. The drive source of the MG 91 is power stored in the power storage unit 26, and part of this power is stored using the hydraulic oil discharged from the first and second main pumps 71 and 72.

  When the sub pump 89 is rotated by the driving force of the MG 91, the assist flow rate is discharged from the sub pump 89. The controller 90 controls the opening degree of the first and second electromagnetic proportional throttle valves 42 and 43 in accordance with the pressure signals from the first and second pressure sensors 13 and 24, and apportions the discharge amount of the sub pump 89. 1 and 2 are supplied to the circuit systems 75 and 78.

  First, the case where the turning motor 76 connected to the first circuit system 75 is driven will be described.

  When the controller 90 switches the operation valve 2 in one direction, one passage 28 communicates with the first main pump 71, the other passage 29 communicates with the tank, and the turning motor 76 rotates.

  If the pressure in the passages 28 and 29 is not maintained at a pressure required for the turning operation or the braking operation, the turning motor 76 cannot be turned or braked. Therefore, in order to keep the pressure in the passages 28 and 29 at the turning pressure or the brake pressure, the controller 90 controls the load of the turning motor 76 while controlling the tilt angle of the hydraulic motor 88.

  When hydraulic oil is supplied to the hydraulic motor 88 through the introduction passage 47 and the connection passage 46 and the hydraulic motor 88 obtains a rotational force, the rotational force acts on the MG 91 that rotates coaxially. The rotational force of the hydraulic motor 88 acts as an assist force for the MG 91. Therefore, the power consumption of the MG 91 can be reduced by the amount of the rotational force of the hydraulic motor 88. Further, the rotational force of the sub pump 89 can be assisted by the rotational force of the hydraulic motor 88.

  When the pressure in the connection passage 46 system becomes lower than the turning pressure or the brake pressure for some reason, the controller 90 closes the electromagnetic switching valve 50 based on the pressure signal from the pressure sensor 51 and turns the turning motor 76 on. Try not to affect it. When pressure oil leaks in the connecting passage 46, the safety valve 52 functions to prevent the pressure in the passages 28 and 29 from becoming unnecessarily low, thereby preventing the turning motor 76 from running away.

  Next, the case where the boom cylinder 77 is operated will be described.

  When the operation valve 16 is switched to operate the boom cylinder 77, the operation direction and the operation amount of the operation valve 16 are detected by a sensor (not shown) provided in the operation valve 16, and the operation signal is sent to the controller 90. Is output.

  In response to the operation signal from the sensor, the controller 90 determines whether the operator is going to raise or lower the boom cylinder 77. If the controller 90 determines that the boom cylinder 77 is raised, the controller 90 keeps the proportional solenoid valve 36 in the fully open position, which is the normal state. At this time, the controller 90 controls the rotational speed of the MG 91 and the tilt angle of the sub pump 89 while keeping the electromagnetic on-off valve 54 in the closed position.

  On the other hand, if the controller 90 determines that the boom cylinder 77 is lowered, the controller 90 calculates the lowering speed of the boom cylinder 77 requested by the operator according to the operation amount of the operation valve 16, and closes the proportional solenoid valve 36 to open and close the electromagnetic valve. The valve 54 is switched to the open position. As a result, the entire amount of return oil from the boom cylinder 77 is supplied to the hydraulic motor 88.

  However, if the flow rate consumed by the hydraulic motor 88 is less than the flow rate required to maintain the descending speed obtained by the operator, the boom cylinder 77 cannot maintain the descending speed obtained by the operator. In such a case, the controller 90 returns the flow rate higher than the flow rate consumed by the hydraulic motor 88 to the tank 94 based on the operation amount of the operation valve 16, the tilt angle of the hydraulic motor 88, the rotational speed of the MG 91, and the like. Thus, the opening degree of the proportional solenoid valve 36 is controlled to maintain the lowering speed of the boom cylinder 77 required by the operator.

  When pressure oil is supplied to the hydraulic motor 88, the hydraulic motor 88 rotates, and the rotational force acts on the MG 91 that rotates coaxially. The rotational force of the hydraulic motor 88 acts as an assist force for the MG 91. Therefore, the power consumption of the MG 91 can be reduced by the amount of the rotational force of the hydraulic motor 88. On the other hand, the sub pump 89 can be rotated only by the rotational force of the hydraulic motor 88 without supplying power to the MG 91.

  Next, a case where the turning operation of the turning motor 76 and the lowering operation of the boom cylinder 77 are performed simultaneously will be described.

  When lowering the boom cylinder 77 while turning the turning motor 76, the pressure oil from the turning motor 76 and the return oil from the boom cylinder 77 merge in the connection passage 46 and are supplied to the hydraulic motor 88.

  At this time, even if the pressure in the introduction passage 47 rises and becomes higher than the turning pressure or the braking pressure of the turning motor 76, the check valves 48 and 49 are not affected, so the turning motor 76 is not affected. When the pressure on the connection passage 46 side becomes lower than the turning pressure or the brake pressure, the controller 90 closes the electromagnetic switching valve 50 based on the pressure signal from the pressure sensor 51.

  Therefore, when the turning operation of the turning motor 76 and the lowering operation of the boom cylinder 77 are performed simultaneously, the tilt angle of the hydraulic motor 88 can be determined based on the required lowering speed of the boom cylinder 77 regardless of the turning pressure or the brake pressure. That's fine. In any case, the output of the sub-pump 89 can be assisted by the output of the hydraulic motor 88, and the hydraulic oil discharged from the sub-pump 89 is divided by the first and second electromagnetic proportional throttle valves 42, 43, and the first, Two circuit systems 75 and 78 can be supplied.

  When the hydraulic motor 88 is used as a drive source and the MG 91 is used as a generator, the sub-pump 89 is set to a zero tilt angle and is in an almost no load state. If the hydraulic motor 88 maintains an output necessary for rotating the MG 91, the output of the hydraulic motor 88 can be used to cause the MG 91 to function as a generator. Further, the generator 1 can generate power using the output of the engine 73.

  Since this system is provided with check valves 44 and 45, and also with an electromagnetic switching valve 50, an electromagnetic on-off valve 54, and electromagnetic valves 58 and 59, for example, even when the hydraulic motor 88 and the sub pump 89 system break down. The first and second main pumps 71 and 72 can be hydraulically disconnected from the hydraulic motor 88 and the sub pump 89.

  In particular, the electromagnetic switching valve 50, the electromagnetic open / close valve 54, and the electromagnetic valves 58 and 59 maintain the closed position by the spring force of the spring when in the normal state, and fully open when the proportional electromagnetic valve 36 is also in the normal state. In order to maintain the position, even if the electric system fails, the first and second main pumps 71 and 72, and the hydraulic motor 88 and the sub pump 89 can be hydraulically disconnected.

  Next, a power storage unit 26 as an example of a power storage device in the control device for a hybrid construction machine configured as described above will be described.

  FIG. 2 is a configuration circuit diagram of the power storage unit 26 according to the embodiment of the present invention.

  The power storage unit 26 includes a battery circuit 100, a battery 101, a switch circuit 102 that switches power of the battery 101, a power storage unit control device 106 that controls switching of the switch circuit 102, a capacitor 104, and a load (inverter) 92, etc.) are connected to the battery circuit 100 and configured.

  The switch circuit 102 includes a first contactor 111 and a second contactor 112.

  A first contactor 111 and a second contactor 112 are connected in parallel to the positive side of the battery circuit 100. A capacitor 104 is connected across the positive electrode side and the negative electrode side closer to the load (inverter 92, battery charger 25, etc.) than the first contactor 111 and the second contactor 112.

  The capacitor 104 smoothes the electric power input / output to / from the battery 101, thereby suppressing inrush current when the first contactor 111 or the second contactor 112 is turned on / off and voltage fluctuation of the battery 101.

  The power storage unit control device 106 controls the open / close state of the first contactor 111 and the second contactor 112 to supply the power of the battery 101 to the load or charge from the load side, or to cut off the battery 101 and the load. Control.

  The battery 101 is a capacitor that can store a large amount of power by connecting a plurality of secondary battery cells. A secondary battery cell is comprised from a lithium ion battery, a nickel metal hydride battery, etc., for example. Moreover, you may be comprised with the electric double layer capacitor instead of a battery.

  The first contactor 111 is configured by connecting a first switch 121 and a current limiting element 122 in series. The second contactor 112 is configured by a second switch 123. The first contactor 111 and the second contactor 112 are inserted in the battery circuit 100 so as to be parallel to each other. The current limiting element 122 is configured by a resistor or the like having linear or nonlinear characteristics.

  In the battery circuit 100, a first voltage detector 131 is provided at a point A provided between the battery 101 and the first contactor 111. A second voltage detection unit 132 is provided at a point B provided between the second contactor 112 and the output terminal 105. The first voltage detector 131 and the second voltage detector 132 are connected to the power storage unit controller 106. The power storage unit control device 106 detects the voltage at the point A and the point B by the first voltage detection unit 131 and the second voltage detection unit 132.

  Next, the operation of the power storage unit control device 106 will be described.

  As described above, the power storage unit 26 is charged with electric power regenerated by the standby flow rate discharged from the first and second main pumps 71 and 72. Further, the MG 91 is driven using the charged electric power, and each operation can be assisted by the hydraulic pressure generated by the sub pump 89.

  When operating the hybrid construction machine, the operator gives a key-on or the like to instruct the start of the operation of the hybrid construction machine. Based on this instruction, the controller 90 starts the control of the hydraulic system, and issues a command to turn on the power storage unit 26 to the power storage unit control device 106.

  The power storage unit control device 106 receives a command from the controller and executes an operation of turning on the switch circuit 102 of the power storage unit 26.

  Specifically, the power storage unit control device 106 first turns on the first contactor 111. In the first contactor 111, since the first switch 121 and the current limiting element 122 are connected in series, the capacitor 104 is gradually charged by the action of the current limiting element 122 and the capacitor 104. As a result, the voltage at point B gradually increases from zero.

  The power storage unit control device 106 monitors the voltage at the point A and the voltage at the point B after turning on the first contactor 111. Then, when the voltage at point B rises and the voltage at point A and the voltage at point B become substantially equal, power storage unit control device 106 turns on second contactor 112. As a result, the battery 101 and the output terminal 105 are directly connected, and power to the battery 101 is input / output.

  In this manner, by gradually increasing the output of the power storage unit 26 by the current limiting element 122 and the capacitor 104, an inrush current when the first contactor 111 and the second contactor 112 are turned on can be prevented.

  Here, conventionally, after the second contactor 112 is turned on, the first contactor 11 including the current limiting element 122 is normally cut off. On the other hand, the hybrid construction machine on which the power storage unit 26 is mounted is used in a state where there is a possibility that a lot of vibrations and shocks are applied. There is a possibility that the input / output of the electric power of the power storage unit 26 is cut off due to the contact of 121 or the second switch 123 being separated. When the power input / output of the power storage unit 26 is interrupted, the power supplied to the load such as the inverter 92 is interrupted, and the operation of the inverter 92 and the like becomes defective.

  Therefore, in this embodiment, as described below, the power storage unit control device 106 is configured to maintain the first contactor 111 in the input state after the second contactor 112 is input.

  FIG. 3 is a flowchart of the control process of the power storage unit 26 executed by the power storage unit control device 106 according to the embodiment of the present invention.

  The flowchart shown in FIG. 3 starts when the controller 90 issues a command to turn on the power of the power storage unit 26.

  When the power storage unit control device 106 receives a command to turn on the power of the power storage unit 26 from the controller 90, the power storage unit control device 106 first turns on the first contactor 111 (step S10).

  After turning on the first contactor 111, the power storage unit controller 106 detects the voltage at the point A and the voltage at the point B by the first voltage detector 131 and the second voltage detector 132 (step S20). Then, it is determined whether or not the voltage at point B has risen and the voltage at point A and the voltage at point B are substantially equal (step S30). If it is determined that the voltage at point B is still less than the voltage at point A, the process returns to step S20 and the process is repeated.

  If it is determined that the voltage at point A is substantially equal to the voltage at point B, the power storage unit control device 106 turns on the second contactor 112 (step S40). When the second contactor 112 is turned on, the battery 101 and the output terminal 105 are directly connected, and power input / output of the power storage unit 26 can be performed.

  Even after the second contactor 112 is turned on, the power storage unit control device 106 keeps the first contactor 111 turned on.

  Next, the electrical storage unit control apparatus 106 determines whether the 2nd contactor 112 was interrupted | blocked (step S50). If it is determined that the second contactor 112 is not blocked, the process of step S50 is repeated.

  Even after the second contactor 112 is turned on, the power storage unit control device 106 detects the voltage at the point A and the voltage at the point B using the first voltage detection unit 131 and the second voltage detection unit 132. When it is determined that the voltage at point B is lower than the voltage at point A by the voltage drop due to the current limiting element 122, the power storage unit control device 106 enters the conductive state of the second contactor 112. It is determined that an abnormality has occurred, and an error is transmitted to the controller 90 (step S60).

  When an error is transmitted from the power storage unit control device 106, the controller 90 executes an end process for the inverter 92 and other electrical devices. Thereafter, the controller 90 transmits a command to shut off the power storage unit 26 to the power storage unit control device 106.

  At this time, even if an abnormality occurs in the conduction state of the second contactor 112, the first contactor 111 can output power. Since the first contactor 111 includes the current limiting element 122, when the second contactor 112 is cut off, only the electric power whose voltage has been dropped by the current limiting element 122 can be output. Power can be provided for the time required to safely stop.

  When the power storage unit control device 106 receives the command transmitted from the controller 90, the power storage unit control device 106 performs control such as blocking the first contactor 111, and blocks the power storage unit 26 (step S70).

  With the above processing, even when an abnormality occurs in the conduction state of the second contactor 112, the first contactor 111 can secure the power source of the inverter 92 and the like, and the inverter 92 and the like can be normally terminated. It becomes possible.

  In the embodiment of the present invention configured as described above, in the power storage unit 26 provided in the hybrid construction machine, when the power of the power storage unit 26 is turned on by a command from the controller 90, the power storage unit control device 106 After the first switch 121 of the first contactor 111 is turned on and the capacitor 104 is charged, the second switch 123 of the second contactor 112 is turned on while the first switch 121 of the first contactor 111 is kept turned on.

  With this configuration, even when an abnormality occurs in the conduction state of the second switch 123 of the second contactor 112, input / output of power can be secured by the first switch 121 of the first contactor 111. In addition, the electric device such as the inverter 92 connected to the power storage unit 26 can be safely stopped.

  In addition, the first contactor 111 includes a current limiting element 122, and the battery circuit 100 includes a first voltage detector 131 that detects a voltage at point A between the switch circuit 102 and the battery 101, a switch circuit 102, and an output. The power storage unit control device 106 monitors the voltage before and after the switch circuit 102 to detect the voltage at the point B between the terminal 105 and the second contactor 112. It is possible to detect that an abnormality has occurred in the conduction state of the second switch 123.

  Further, when the storage unit control device 106 detects that an abnormality has occurred in the conduction state of the second switch 123 of the second contactor 112, an error or the like is output to the controller 90, so that the hybrid construction is performed by the controller 90. Electrical equipment mounted on the machine can be safely stopped.

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Generator 25 Battery charger 26 Electric power storage unit 71 1st main pump 72 2nd main pump 73 Engine 88 Hydraulic motor 89 Sub pump 90 Controller 91 Motor generator (MG)
92 Inverter 100 Battery circuit 101 Battery 102 Switch circuit 104 Capacitor 105 Output terminal 106 Storage unit control device 111 First contactor 112 Second contactor 121 First switch 122 Current limiting element 123 Second switch 131 First voltage detector 132 Second voltage Detection unit

Claims (3)

A power storage unit for storing electric power;
A switch circuit comprising a first switch and a second switch having a current limiting element, wherein the connection between the power storage unit and the load is interrupted by the first switch and the second switch;
A capacitor for smoothing the power input to and output from the power storage unit;
A first voltage detection unit that detects a voltage on the power storage unit side of the switch circuit;
A second voltage detector that detects a voltage on the load side of the switch circuit;
A power storage unit control device of a power storage device for controlling the switch circuit;
Equipped with a,
The power storage unit controller is
When turning on and off the power to the power storage unit, turn on the first switch,
The second switch is turned on after the capacitor is charged, and the first switch is kept turned on after the second switch is turned on,
When a difference occurs between the voltage detected by the second voltage detection unit and the voltage detected by the first voltage detection unit after the second switch is turned on, an error signal is output.
The power storage device , wherein the first switch is shut off after the load stop process is performed in response to the error signal . A power storage circuit that connects the power storage unit and a load that supplies power to the power storage unit or consumes the power of the power storage unit;
The storage circuit is
The switch circuit is connected to the positive electrode side of the power storage unit,
The capacitor is connected to the load side of the switch circuit across the positive electrode side and the negative electrode side of the power storage unit ,
When the voltage detected by the second voltage detection unit becomes equal to the voltage detected by the first voltage detection unit, the second switch is turned on while maintaining the turning on of the first switch. The power storage device according to claim 1.   A variable displacement pump;
  An operation valve for controlling the flow rate of the discharged oil guided from the variable displacement pump to the actuator;
  A regenerative hydraulic motor that is rotated by the discharge oil of the variable displacement pump;
  A generator for driving in association with rotation of the hydraulic motor;
  A power storage device that stores electric power generated by driving the generator;
  An inverter provided between the generator and the power storage device;
  A hybrid control device that controls operations of the variable displacement pump, the operation valve, the generator, the power storage device, and the inverter;
A hybrid construction machine comprising:
  The power storage device
    A power storage unit for storing electric power;
    A switch circuit comprising a first switch and a second switch having a current limiting element, wherein the first switch and the second switch intermittently connect the power storage unit and the inverter;
    A capacitor for smoothing the power input to and output from the power storage unit;
    A first voltage detection unit that detects a voltage on the power storage unit side of the switch circuit;
    A second voltage detector that detects a voltage on the load side of the switch circuit;
    A power storage unit control device of a power storage device for controlling the switch circuit,
    The power storage unit control device turns on the first switch when turning on / off power to the power storage unit, turns on the second switch after the capacitor is charged, and turns on the second switch. Even after being turned on, the first switch is kept turned on, and after the second switch is turned on, the voltage detected by the second voltage detector and the voltage detected by the first voltage detector If a difference occurs, an error signal is output to the hybrid control device,
    The hybrid control device performs a stop process of the inverter according to the error signal,
    The power storage unit control circuit shuts off the first switch after the inverter is stopped.