Construction machine control device and construction machine

Abstract

To provide a control device of a construction machine capable of consuming surplus power while properly operating a storage battery and an auxiliary machine even if a fuel cell is operated at a minimum output, and the construction machine.SOLUTION: When the hydraulic actuator 13 is not driven after the construction machine is started, the control device BC of the construction machine of the present invention controls the fuel cell 2 to generate power at the minimum output and controls the electric motor 5 to consume the surplus power obtained based on the minimum generated power generated by the fuel cell 2, the charging power of the storage battery 3, and the power consumption consumed by the auxiliary machine 1 by controlling the auxiliary machine 1 at the target value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for a construction machine that controls the construction machine, and a construction machine equipped with the same. [Background technology]

[0002] In recent years, electrification has been promoted from the viewpoint of carbon neutrality, and there are systems that use fuel cells as a power source and are equipped with storage batteries that charge and discharge the electricity generated by the fuel cells. Because it takes time to restart a fuel cell once power generation is stopped, a known operating method is to operate the fuel cell at minimum output without stopping power generation. Furthermore, if the electricity generated at the minimum output is continuously charged into the storage battery, there is a risk of the storage battery being overcharged. To solve these problems, a control device for a fuel cell system is disclosed, for example, in Patent Document 1.

[0003] The control device for a fuel cell system disclosed in Patent Document 1 is a control device for a fuel cell system including a fuel cell that generates electricity when supplied with fuel gas and oxidant gas, load means that is driven using the electricity generated by the fuel cell, power output adjusting accessories that increase or decrease the electricity generated by the fuel cell, and external power output adjusting accessories that do not contribute to increasing or decreasing the electricity generated by the fuel cell, and includes state determination means that detects the operating state of the fuel cell based on an external sensor signal, total electricity generation calculation means that calculates the total amount of electricity generated by the fuel cell that is not consumed by the load means, power consumption calculation means that calculates the electricity consumed by the power output adjusting accessories, first calculation means that calculates a first target operating point as a target for the operation of the power output adjusting accessories, second calculation means that calculates a second target operating point as a target for the operation of the external power output adjusting accessories, and calculates the surplus electricity not consumed by the power output adjusting accessories by subtracting the first amount of electricity consumed from the total electricity generated. The system comprises surplus power calculation means, and control means for controlling the second calculation means so that, when the state determination means determines that the operating state of the fuel cell is in a minimum output state, the total amount of power generated is calculated by the total power generation calculation means, the first calculation means calculates a first target operating point for the power output adjusting auxiliary equipment, the surplus power calculation means calculates the amount of surplus power using this first amount of power consumption, and the second calculation means calculates a second target operating point at which this surplus power is consumed by the power output adjusting auxiliary equipment, and storage means for charging and discharging power generated by the fuel cell, wherein the surplus power calculation means sets the surplus power to a value obtained by subtracting the first power consumption by the power output adjusting auxiliary equipment and the chargeable power of the storage means from the power generated when the fuel cell is in the minimum output state, and the control means controls the second calculation means so that the power consumed by the power output adjusting auxiliary equipment is at least the calculated surplus power and not more than the sum of the surplus power, the chargeable power, and the dischargeable power. In this fuel cell system control device, the auxiliary equipment for increasing or decreasing power output includes at least a compressor that supplies air to the fuel cell, and the external auxiliary equipment for increasing or decreasing power output includes at least one of a cooling water supply pump that supplies cooling water to the fuel cell, a humidification pump that controls the flow rate of water that humidifies the air and hydrogen supplied to the fuel cell, and a radiator fan that cools the cooling water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-203583 Summary of the Invention [Problem to be solved by the invention]

[0005] The fuel cell system control device disclosed in Patent Document 1 is designed to use the external power output adjusting device to consume the surplus power generated in the minimum output state that is not consumed by the power output adjusting device and the power storage means. If the external power output adjusting device includes a cooling water supply pump that supplies cooling water to the fuel cell and a radiator fan that cools the cooling water, there is a risk that the fuel cell will be overcooled. If an attempt is made to maintain the fuel cell at an appropriate temperature (target temperature), there is a risk that the external power output adjusting device will not be able to consume the surplus power.

[0006] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a control device for construction machinery that can consume surplus electricity while properly operating the storage battery and auxiliary machinery even when the fuel cell is operated at minimum output, and a construction machine equipped with the same. [Means for solving the problem]

[0007] After extensive investigation, the inventors have found that the above object can be achieved by the present invention, which is described below. That is, a control device for a construction machine according to one aspect of the present invention comprises a hydraulic actuator that drives a work machine to perform a predetermined task, a hydraulic pump that drives the hydraulic actuator, an electric motor that drives the hydraulic pump, a fuel cell that generates electricity by an oxidation-reduction reaction between fuel and an oxidant, a storage battery that charges and discharges the electricity generated by the fuel cell, auxiliary machinery that consumes electricity when at least one of the hydraulic actuator, the hydraulic pump, the electric motor, the fuel cell, and the storage battery is used as a main machinery, and a control circuit for each of the hydraulic actuator, the hydraulic pump, the electric motor, the fuel cell, and the storage battery. and a control unit that controls the electric motor, wherein the electric motor is supplied with power from at least one of the fuel cell and the storage battery, and the auxiliary equipment is supplied with power from at least one of the fuel cell and the storage battery, and the control unit controls the fuel cell to generate power at a minimum output when the construction machine has been started and the hydraulic actuator is not being driven, and controls the electric motor so that it consumes surplus power calculated based on the minimum generated power generated by the fuel cell, the charging power of the storage battery, and the power consumed by the auxiliary equipment when the auxiliary equipment is controlled at a target value. Preferably, the above-mentioned control device for a construction machine further includes a flow path that flows hydraulic oil discharged from the hydraulic pump when the electric motor is driven with the surplus power to a tank that stores the hydraulic oil, without driving the hydraulic actuator.

[0008] When controlling the fuel cell at minimum output, this type of construction machinery control device uses the electric motor to consume excess power that is not consumed by the storage battery and auxiliary equipment.Therefore, even when the fuel cell is operated at minimum output, the storage battery and auxiliary equipment can be operated appropriately and excess power can be consumed.

[0009] In another aspect, in the above-mentioned construction machine control device, the control unit calculates the surplus power by subtracting the power consumption from the minimum power generation when the charging rate of the storage battery exceeds an upper limit value.

[0010] Such a control device for construction machinery can consume surplus power so that the storage battery is not overcharged beyond the upper limit.

[0011] In another aspect, in the control device for the above-mentioned construction machine, the auxiliary equipment is a battery auxiliary equipment when the storage battery is included as a main equipment, and includes a heating unit that heats a fluid, a radiator connected to the heating unit and exchanging heat between the fluid and the surrounding environment, a fan that blows air to the radiator to cool the fluid in the radiator, a flow path member that forms a flow path from the radiator back to the radiator via the heating unit and the storage battery and through which the fluid flows, and a pump interposed in the flow path member that circulates the fluid from the radiator to the radiator via the heating unit and the storage battery, and the control unit controls the fan to stop blowing air and controls the heating unit to heat the fluid when the temperature of the storage battery is below a lower limit temperature.

[0012] Such a control device for construction machinery can operate the storage battery at an appropriate temperature without overcooling the storage battery.

[0013] In another aspect, the above-mentioned construction machine control device further includes an operating lever that accepts operation input for the work machine, and the control unit determines whether the hydraulic actuator is being driven based on the operation input of the operating lever.

[0014] This makes it possible to provide a control device for a construction machine that determines whether or not a hydraulic actuator is being driven based on an operation input of an operating lever.

[0015] In another aspect, the control device for the above-mentioned construction machine further includes a lever lock that switches between valid and invalid input operation of the operating lever, and the control unit determines whether the hydraulic actuator is operating based on the operation input of the operating lever and the operation input of the lever lock.

[0016] This makes it possible to provide a control device for a construction machine that determines whether or not a hydraulic actuator is being driven based on an operation input of an operating lever and an operation input of a lever lock.

[0017] In another aspect, in the above-described construction machine control device, the control unit controls the electric motor so that the rotation speed corresponds to the surplus power.

[0018] Such a control device for a construction machine can appropriately consume surplus power by the electric motor.

[0019] A construction machine according to another aspect of the present invention includes any one of the above-described control devices for a construction machine.

[0020] This makes it possible to provide a construction machine equipped with any of the above-mentioned construction machine control devices. In such a construction machine, when the fuel cell is controlled at minimum output, the electric motor consumes surplus power that is not consumed by the storage battery and auxiliary machinery, so even when the fuel cell is operated at minimum output, the storage battery and auxiliary machinery can be operated appropriately and surplus power can be consumed. [Effects of the Invention]

[0021] The construction machine control device according to the present invention can consume surplus power while properly operating the storage battery and auxiliary machinery even when the fuel cell is operated at minimum output. The present invention can provide a construction machine equipped with such a construction machine control device. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a side view showing a hydraulic excavator equipped with a control device for a construction machine according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control device for the construction machine. [Figure 3] FIG. 2 is a diagram for explaining an auxiliary device in the control device of the construction machine. [Figure 4] 4 is a diagram for explaining a first mode of charging and discharging of a storage battery in the control device for the construction machine. FIG. [Figure 5] 6 is a flowchart showing the operation of the control device of the construction machine regarding a second accessory. [Figure 6] 5 is a flowchart showing the operation of the control device of the construction machine regarding the consumption of surplus power. [Figure 7] 6 is a diagram for explaining a second mode of charging and discharging of the storage battery in the control device for the construction machine. FIG. [Figure 8] FIG. 10 is a block diagram showing the configuration of a control device for a construction machine in a modified embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. In addition, components with the same reference numerals in each drawing indicate the same components, and their description will be omitted as appropriate. In this specification, when referring to a general term, a reference numeral without a subscript is used, and when referring to an individual component, a reference numeral with a subscript is used.

[0024] The construction machine control device in the embodiment is installed and used in a construction machine (construction machine) for performing a predetermined task, such as a hydraulic excavator, a crane, a wheel roller, etc. Here, as an example, a case where the control device is installed in a hydraulic excavator will be described, but of course, this construction machine control device may also be installed and used in other types of construction machine.

[0025] Fig. 1 is a side view showing a hydraulic excavator equipped with a construction machine control device in an embodiment. Fig. 2 is a block diagram showing the configuration of the construction machine control device. Fig. 3 is a diagram for explaining an auxiliary device in the construction machine control device. Fig. 4 is a diagram for explaining a first mode of charging and discharging of a storage battery in the construction machine control device. The horizontal axis of Fig. 4 is the difference between the target value and the measured value at the state of charge (SOC), and the vertical axis is the required power of the storage battery.

[0026] In the embodiment, the hydraulic excavator HS equipped with a construction machinery control device is a construction machine for performing work that can be performed by an excavator, and, for example, as shown in FIG. 1, comprises a lower traveling body 101 having a left traveling crawler 101L and a right traveling crawler (not shown), an upper frame 102 that is rotatably mounted on the lower traveling body 101 and serves as a base, a machine room 103 that is mounted on the upper frame 102 and has a construction machinery control device BC (described below) and the like disposed therein, a work attachment 104 that is mounted on the upper frame 102 so that it can be raised and lowered, and a cab room (operation room) 105 that has an operation lever 9 and the like in the control device BC for operating the work attachment 104.

[0027] The work attachment 104 is a mechanism for performing a predetermined task according to the type of construction machine HS. In this embodiment, since the work attachment 104 is a hydraulic excavator HS, the work attachment 104 has, for example, a boom 141, an arm 142 connected to the tip of the boom 141, and a bucket 143 swingably attached to the tip of the arm 142. The boom 141 rises and falls relative to the upper frame 102 as a boom cylinder 144a extends and retracts. The arm 141 swings relative to the boom 141 as an arm cylinder 144b extends and retracts. The bucket 143 swings relative to the arm 142 as a bucket cylinder 144c extends and retracts.

[0028] The construction machinery control device BC provided for use in such a hydraulic excavator HS includes, for example, an auxiliary device 1 (1A to 1D), a fuel cell 2, a storage battery 3, an inverter 4, an electric motor 5, a hydraulic pump 6, a vehicle controller 7, an accelerator potentiometer 8, an operating lever 9, a lever lock 10, an unload valve 11, a control valve 12, and a hydraulic actuator 13, as shown in Figures 2 and 3.

[0029] The hydraulic actuator 13 is a device that drives a work machine to perform a predetermined task. In the example shown in Fig. 1, the work machine is a work attachment 104, and the hydraulic actuator 13 is a boom cylinder 144a, an arm cylinder 144b, and a bucket cylinder 144c, each of which is, for example, a hydraulic cylinder.

[0030] The hydraulic pump 6 is electrically connected to the vehicle body controller 7 and drives the hydraulic actuator 13 under the control of the vehicle body controller 7. It applies pressure to hydraulic oil drawn from a hydraulic oil tank OT, which stores hydraulic oil, and discharges it to the hydraulic actuator 13 via a control valve 12. The hydraulic oil that drives the hydraulic actuator 13 returns to the hydraulic oil tank OT via the control valve 12. While two hydraulic oil tanks OT are shown in FIG. 2 for ease of illustration, the actual machine will have only one hydraulic oil tank OT. This is also true for FIG. 8, which will be described later. The hydraulic pump 6 is equipped with a pressure gauge (not shown) that measures the discharge pressure of the hydraulic pump 6 and a flow meter (not shown) that measures the discharge rate of the hydraulic pump 6, and these are electrically connected to the vehicle body controller 7. The pressure gauge and flow meter each output their measurement results to the vehicle body controller 7. The hydraulic pump 6 is, for example, a swash plate pump, and the swash plate is controlled by a tilt command value from the vehicle body controller 7. The hydraulic pump 6 is not limited to the swash plate type pump, but may be a pump of another type.

[0031] The control valve 12 is electrically connected to the vehicle body controller 7 and is a valve that switches the flow path of the hydraulic oil discharged from the hydraulic pump 6 in accordance with the control of the vehicle body controller 7. When the hydraulic actuator 13 is driven, the control valve 12 connects a flow path from the hydraulic pump 6 to the hydraulic actuator 13 in accordance with the control of the vehicle body controller 7, and also connects a flow path from the hydraulic actuator 13 to the hydraulic oil tank OT. When the hydraulic actuator 13 is not driven, the control valve 12 blocks the flow path from the hydraulic pump 6 to the hydraulic actuator 13 in accordance with the control of the vehicle body controller 7.

[0032] The unloading valve 11 is electrically connected to the vehicle body controller 7 and is a valve that switches the flow path of the hydraulic oil discharged from the hydraulic pump 6 in accordance with the control of the vehicle body controller 7. When the hydraulic actuator 13 is not being driven, the unloading valve 11 connects the flow path from the hydraulic pump 6 to the hydraulic oil tank OT in accordance with the control of the vehicle body controller 7. When the hydraulic actuator 13 is being driven, the unloading valve 11 blocks the flow path from the hydraulic pump 6 to the hydraulic oil tank OT in accordance with the control of the vehicle body controller 7.

[0033] The electric motor 5 is a device that drives the hydraulic pump 6. The electric motor 5 is, for example, a three-phase AC synchronous motor, and is supplied with power from at least one of the fuel cell 2 and the storage battery 3 via the inverter 4. Note that the electric motor 5 is not limited to the three-phase AC synchronous motor, and may be an electric motor of another type.

[0034] The inverter 4 is electrically connected to the vehicle body controller 7, and under the control of the vehicle body controller 7, converts DC power supplied from at least one of the fuel cell 2 and the storage battery 3 into three-phase AC power, and supplies this converted three-phase AC power to the electric motor 5. The inverter 4 is equipped with an ammeter (IV ammeter) not shown that measures the output current of the inverter 4, and a voltmeter (IV voltmeter) not shown that measures the output voltage of the inverter 4, and these are each electrically connected to the vehicle body controller 7. The IV ammeter and the IV voltmeter each output their measurement results to the vehicle body controller 7. The vehicle body controller 7 controls the electric motor 5 via the inverter 4.

[0035] The fuel cell 2 is electrically connected to the vehicle body controller 7 and is a device that generates electricity through an oxidation-reduction reaction between fuel and an oxidant under the control of the vehicle body controller 7. The fuel is, for example, hydrogen, and is supplied to the fuel cell 2 from a fuel tank FT that stores the hydrogen. The oxidant is, for example, oxygen, and the fuel cell 2 takes in oxygen from the atmosphere. The fuel cell 2 is configured with, for example, a solid polymer fuel cell. The fuel cell 2 is equipped with an ammeter (FC ammeter) not shown that measures the output current of the fuel cell 2, an unillustrated voltmeter (FC voltmeter) not shown that measures the output voltage of the fuel cell 2, and unillustrated peripheral devices (FC peripheral devices) for operating the fuel cell 2, such as a boost converter and a compressor, all of which are electrically connected to the vehicle body controller 7. The FC ammeter and the FC voltmeter each output their measurement results to the vehicle body controller 7. The vehicle body controller 7 controls the fuel cell 2 via the FC peripheral devices.

[0036] The storage battery (secondary battery) 3 is electrically connected to the vehicle body controller 7 and is a device that charges and discharges the power generated by the fuel cell 2 under the control of the vehicle body controller 7. The storage battery 3 is, for example, a lead-acid battery or a lithium-ion battery. The storage battery 3 is equipped with an unillustrated ammeter (BT ammeter) that measures the current of the storage battery 3 in response to charging and discharging, an unillustrated voltmeter (BT voltmeter) that measures the terminal voltage of the storage battery 3, an unillustrated thermometer (BT thermometer) that measures the temperature of the storage battery 3, and an unillustrated peripheral circuit (BT peripheral circuit) for operating the storage battery 3, all of which are electrically connected to the vehicle body controller 7. The BT ammeter, BT voltmeter, and BT thermometer each output their measurement results to the vehicle body controller 7. The vehicle body controller 7 controls the storage battery 3 via the fuel cell 2, as described below.

[0037] The auxiliary machines 1 are devices that consume power when at least one of the hydraulic actuator 13, hydraulic pump 6, electric motor 5, fuel cell 2, and storage battery 3 is used as a main machine. In this embodiment, the auxiliary machines 1 include four auxiliary machines, namely, first to fourth auxiliary machines 1A to 1D.

[0038] The first accessory 1A is a device for cooling hydraulic oil when a hydraulic system 21A including a hydraulic actuator 13, a hydraulic pump 6, an unloading valve 11, a control valve 12, etc., is used as the main engine. As shown in FIG. 3 , the first accessory 1A includes a first radiator 22A that exchanges heat between the hydraulic oil and the surrounding environment, and a first fan 23A that blows air to the first radiator 22A to cool the hydraulic oil in the first radiator 22A. The hydraulic oil is drawn from a hydraulic oil tank OT by the hydraulic pump 6 and returned to the hydraulic oil tank OT via the hydraulic system 21A and the first radiator 22A. The first fan 23A consumes power supplied from at least one of the fuel cell 2 and the storage battery 3. The first fan 23A is electrically connected to the vehicle controller 7 and rotates under the control of the vehicle controller 7. The first auxiliary device 1A is provided with an unillustrated ammeter (first auxiliary device ammeter) that measures its input current and an unillustrated voltmeter (first auxiliary device voltmeter) that measures its input voltage, which are electrically connected to the vehicle body controller 7. The first auxiliary device ammeter and the first auxiliary device voltmeter each output their measurement results to the vehicle body controller 7.

[0039] The second auxiliary machine 1B is a machine that cools a fluid such as cooling water and heats it as needed when the high-voltage machine 21B including the storage battery 3, the inverter 4, the electric motor 5, etc. is used as the main machine. As shown in FIG. 3, the first accessory 1A includes, for example, a heating unit 24B such as an electric heater that heats the fluid, a second radiator 22B that is connected to the heating unit 24B and exchanges heat between the fluid and the surrounding environment, a second fan 23B that blows air to the second radiator 22B to cool the fluid in the second radiator 22B, a second flow path member 26B that forms a flow path from the second radiator 22B back to the second radiator 22B via the heating unit 24B and the storage battery 3 and through which the fluid flows, and a pump (second accessory pump) 25B that is interposed in the second flow path member 26B and returns the fluid from the second radiator 22B to the second radiator 22B via the heating unit 24B and the storage battery 3. The second fan 23B, the heating unit 24B, and the second auxiliary pump 25B each consume power supplied from at least one of the fuel cell 2 and the storage battery 3. The second fan 23B is electrically connected to the vehicle body controller 7 and rotates under the control of the vehicle body controller 7. The heating unit 24B is electrically connected to the vehicle body controller 7 and operates under the control of the vehicle body controller 7. The second auxiliary pump 25B is electrically connected to the vehicle body controller 7 and drives under the control of the vehicle body controller 7. The second auxiliary 1B corresponds to an example of a storage battery auxiliary when the storage battery is included as a main engine. The second auxiliary 1B is equipped with an unillustrated ammeter (second auxiliary ammeter) that measures its input current and an unillustrated voltmeter (second auxiliary voltmeter) that measures its input voltage, and these are electrically connected to the vehicle body controller 7. The second auxiliary ammeter and the second auxiliary voltmeter each output their measurement results to the vehicle body controller 7.

[0040] The third and fourth auxiliaries 1C and 1D are auxiliaries when the fuel cell 2 is the main engine. Because their operating temperature ranges are different, the auxiliaries when the fuel cell 2 is the main engine are configured with two third and fourth auxiliaries 1C and 1D. The third auxiliaries 1C are devices that cool fluids such as coolant when the main engine is the FC internal high-voltage equipment 21C, which is configured with FC peripheral equipment, etc., and the fourth auxiliaries 1D are devices that cool fluids such as coolant when the main engine is the FC 21D, which is configured with the fuel cell 2 itself (the so-called fuel cell stack) and fuel piping, etc.

[0041] 3, the third accessory 1C includes, for example, a third radiator 22C that exchanges heat between the fluid and the ambient environment, a third fan 23C that blows air to the third radiator 22C to cool the fluid in the third radiator 22C, a third flow path member 26C that forms a flow path from the third radiator 22C back to the third radiator 22C via the internal FC high-voltage equipment 21C and through which the fluid flows, and a pump (third accessory pump) 25C that is interposed in the third flow path member 26C and returns the fluid from the third radiator 22C to the third radiator 22C via the internal FC high-voltage equipment 21C. The third fan 23C and the third accessory pump 25C each consume power supplied from at least one of the fuel cell 2 and the storage battery 3. The third fan 23C is electrically connected to the vehicle controller 7 and rotates under the control of the vehicle controller 7. The third auxiliary pump 25C is electrically connected to the vehicle body controller 7 and is driven under the control of the vehicle body controller 7. The third auxiliary pump 25C is provided with an unillustrated ammeter (third auxiliary ammeter) that measures its input current and an unillustrated voltmeter (third auxiliary voltmeter) that measures its input voltage, which are electrically connected to the vehicle body controller 7. The third auxiliary ammeter and the third auxiliary voltmeter each output their measurement results to the vehicle body controller 7.

[0042] 3, the fourth accessory 1D includes, for example, a fourth radiator 22D that exchanges heat between a fluid and the ambient environment, a fourth fan 23D that blows air to the fourth radiator 22D to cool the fluid in the fourth radiator 22D, a fourth flow path member 26D that forms a flow path from the fourth radiator 22D back to the fourth radiator 22D via the FC 21D and through which the fluid flows, and a pump (fourth accessory pump) 25D that is interposed in the fourth flow path member 26D and returns the fluid from the fourth radiator 22D to the fourth radiator 22D via the FC 21D. Each of the fourth fan 23D and the fourth accessory pump 25D is supplied with power from at least one of the fuel cell 2 and the storage battery 3 and consumes power. The fourth fan 23D is electrically connected to the vehicle controller 7 and rotates under the control of the vehicle controller 7. The fourth accessory pump 25D is electrically connected to the vehicle body controller 7 and is driven under the control of the vehicle body controller 7. The fourth accessory 1D is provided with an unillustrated ammeter (fourth accessory ammeter) that measures its input current and an unillustrated voltmeter (fourth accessory voltmeter) that measures its input voltage, and these are electrically connected to the vehicle body controller 7. The fourth accessory ammeter and the fourth accessory voltmeter each output their measurement results to the vehicle body controller 7.

[0043] Returning to FIG. 2, the accelerator potentiometer 8 is a rotation speed setting device that is electrically connected to the vehicle body controller 7 and sets the rotation speed of the hydraulic pump 6 (rotation speed of the electric motor 5), and is configured with switches such as a dial switch or a volume switch (variable resistor). The operation input (operation amount) of the accelerator potentiometer 8 is output to the vehicle body controller 7, and the vehicle body controller 7 sets the rotation speed of the hydraulic pump 6 (rotation speed of the electric motor 5) according to the operation amount of the accelerator potentiometer 8. For example, the rotation speed of the hydraulic pump 6 (rotation speed of the electric motor 5) is adjusted between 1000 rpm and 2000 rpm.

[0044] The control lever 9 is electrically connected to the vehicle body controller 7 and is a device that receives operation inputs for the work machine (work attachment 104 in the example shown in FIG. 1), and is configured with, for example, a multi-axis lever switch, a multi-axis joystick, etc. The operation input (operation direction and operation amount) obtained by operating the control lever 9 is output from the control lever 9 to the vehicle body controller 7.

[0045] The lever lock 10 is electrically connected to the vehicle body controller 7 and is a device that switches between valid and invalid input operations of the operating lever 9. When the lever lock 10 is in the locked position, the input operation of the operating lever 9 is invalidated, and when the lever lock 10 is in the unlocked position, the input operation of the operating lever 9 is valid. The lever lock 10 is configured with, for example, a lever switch or joystick that switches between the locked position and the unlocked position. The operation input (locked position or unlocked position) by the input operation of the lever lock 10 is output from the lever lock 10 to the vehicle body controller 7.

[0046] The vehicle body controller 7 is a circuit that controls each of the sections 1 (1A-1D)-6, 11-13, 101, and 104 of the hydraulic excavator HS equipped with the construction machine control device BC according to the function of each section, and controls the entire hydraulic excavator HS equipped with the construction machine control device BC. The vehicle body controller 7 is configured with, for example, a CPU (Central Processing Unit), memory elements, and their peripheral circuits. The memory elements include, for example, a ROM (Read Only Memory), which is a nonvolatile memory element, an EEPROM (Electrically Erasable Programmable Read Only Memory), which is a rewritable nonvolatile memory element, and a RAM (Random Access Memory), which serves as the working memory of the CPU and stores data generated during the execution of a predetermined program. The vehicle body controller 7 is configured with, for example, a one-chip computer, a one-board computer, a PLC (Programmable Logic Controller), etc.

[0047] A first fan rotation speed determination table for determining the rotation speed of the first fan 23A is stored in the vehicle body controller 7. The first fan rotation speed determination table is, for example, a table (correspondence table) that associates the power of the hydraulic pump 6 (hydraulic pump power) and the outside air temperature with the rotation speed of the first fan 23A, and is set and created in advance as appropriate.

[0048] The vehicle body controller 7 selects from the first fan rotation speed determination table the power of the hydraulic pump (hydraulic pump power) obtained by multiplying the discharge pressure of the hydraulic pump 6 measured by the pressure gauge by a tilt command value set as described below, and the rotation speed of the first fan 23A associated with the outside air temperature measured by a thermometer (outside air thermometer) not shown that measures the outside air temperature, and controls the first fan 23A to achieve the selected rotation speed.

[0049] A second fan rotation speed determination table for determining the rotation speed of second fan 23B is stored in vehicle body controller 7. The second fan rotation speed determination table is, for example, a table (correspondence table) that associates the power consumption of electric motor 5, the outside air temperature, and the rotation speed of second fan 23B, and is set and created in advance as appropriate.

[0050] The vehicle controller 7 selects from the second fan rotation speed determination table the power consumption of the electric motor 5, which is calculated by multiplying the output current of the inverter 4 measured by the IV ammeter by the output voltage of the inverter 4 measured by the IV voltmeter, and the rotation speed of the second fan 23B, which corresponds to the outside air temperature measured by the outside air thermometer, and controls the second fan 23B to achieve the selected rotation speed.

[0051] The vehicle body controller 7 repeatedly determines at predetermined intervals whether the temperature of the storage battery 3 measured by the BT thermometer is below a preset lower limit temperature. If the result of this determination is that the temperature of the storage battery 3 is below the lower limit temperature, the vehicle body controller 7 controls the second fan 23B to stop blowing air from the second fan 23B and controls the heating unit 24B to heat the fluid. The heating unit 24B is controlled to a preset temperature. If the result of the determination is that the temperature of the storage battery 3 is not below the lower limit temperature, the vehicle body controller 7 controls the heating unit 24B to stop heating by the heating unit 24B and controls the second fan 23B to blow air at the selected rotation speed. The lower limit temperature is set appropriately in advance.

[0052] A third fan rotation speed determination table for determining the rotation speed of each of the third and fourth fans 23C, 24D is stored in the vehicle body controller 7. The third fan rotation speed determination table is, for example, a table (correspondence table) that associates the output power of the fuel cell 2 and the outside air temperature with the rotation speed of each of the third and fourth fans 23C, 23D, and is set and created in advance as appropriate.

[0053] The vehicle body controller 7 selects from the third fan rotation speed determination table the output power of the fuel cell 2, which is calculated by multiplying the output current of the fuel cell 2 measured by the FC ammeter by the output voltage of the fuel cell 2 measured by the FC voltmeter, and the rotation speeds of the third and fourth fans 23C, 23D that correspond to the outside air temperature measured by the outside air thermometer, and controls each of the third and fourth fans 23C, 23D to achieve the selected rotation speeds.

[0054] The vehicle body controller 7 controls the second accessory pump 25B to be driven at a predetermined discharge pressure and discharge rate while the second accessory 1B is in operation. Similarly, the vehicle body controller 7 controls the third and fourth accessory pumps 25C and 25D to be driven at a predetermined discharge pressure and discharge rate while the third and fourth accessories 1C and 1D are in operation.

[0055] The vehicle body controller 7 controls the charging and discharging of the storage battery 3 based on a preset target value (target charging rate (target SOC)) and the measured charging rate (detected SOC value) of the storage battery 3. The charging rate is a percentage (%) obtained by dividing the charge capacity (storage capacity) [Ah] of electricity actually stored in the storage battery 3 by the charge capacity [Ah] of the storage battery 3 when fully charged ((charging rate [%]) = ((charge capacity [Ah] actually charged in the storage battery 3) / (charge capacity [Ah] of the storage battery 3 when fully charged)) × 100). More specifically, the charging and discharging of the storage battery 3 is controlled according to the power generated by the fuel cell 2. The vehicle body controller 7 controls the fuel cell 2 so that the storage battery 3 is charged from the fuel cell 2 when the detected SOC value falls below the target SOC, and so that the storage battery 3 is discharged when the detected SOC value exceeds the target SOC. The storage battery 3 is indirectly controlled by controlling the fuel cell 2. The target SOC is set in advance as appropriate to a value smaller than the maximum possible charging rate (upper limit of the charging rate) set, for example, in the specifications of the storage battery 3. More specifically, the vehicle body controller 7 stores a function (charge / discharge correspondence function) that indicates the relationship between the charging rate difference ΔSOC between the target SOC and the detected SOC value and the required power of the storage battery, as shown in Fig. 4 as an example. The charging rate difference ΔSOC is the result of subtracting the detected SOC value from the target SOC (ΔSOC = (target SOC) - (detected SOC)). The battery required power is one of the power to charge the storage battery 3, the power to discharge the storage battery 3, and the power (=0) that is neither charged nor discharged. When the battery required power is positive, the battery required power represents the power to charge the storage battery 3. When the battery required power is negative, the battery required power represents the power to discharge the storage battery 3. When the battery required power is 0, the battery required power represents no charging or discharging of the storage battery 3. In the example shown in FIG. 4 , the charge / discharge correspondence function indicates that when the storage rate difference ΔSOC is below a preset lower limit difference ΔSOC1 (ΔSOC1<0) (ΔSOC<ΔSOC1), the battery required power is charging power DP1 (DP1>0). In this case, the vehicle controller 7 controls the fuel cell 2 so that the storage battery 3 is charged with charging power DP1.The charge / discharge correspondence relationship function determines whether the battery required power is discharge power |DP2| (DP2<0) when the charging rate difference ΔSOC exceeds a preset upper limit difference ΔSOC2 (ΔSOC2>0) (ΔSOC>ΔSOC2). In this case, the vehicle body controller 7 controls the fuel cell 2 so that the battery 3 is discharged at the discharge power |DP2|. When the charging rate difference ΔSOC is equal to or greater than the lower limit difference ΔSOC1 but less than 0 (ΔSOC1≦ΔSOC<0), the charge / discharge correspondence relationship function determines whether the battery required power decreases proportionally from charge power DP1 to 0 as the charging rate difference ΔSOC increases. In this case, the vehicle body controller 7 controls the fuel cell 2 so that the battery 3 is charged at charge power DP(ΔSOC) (>0) calculated by the charge / discharge correspondence relationship function. When the charging rate difference ΔSOC exceeds 0 and is equal to or less than the upper limit difference ΔSOC2 (0<ΔSOC≦ΔSOC2), the charging / discharging correspondence relationship function causes the battery required power to decrease proportionally from 0 to charging power −DP2 (DP2<0) as the charging rate difference ΔSOC increases. In other words, the battery required power increases proportionally from 0 to discharging power |DP2| as the charging rate difference ΔSOC increases. In this case, the vehicle body controller 7 controls the fuel cell 2 so that the storage battery 3 is discharged at the discharge power |DP(ΔSOC)| (DP(ΔSOC)<0) calculated by the charging / discharging correspondence relationship function. When the charging rate difference ΔSOC is 0 (ΔSOC=0), the charging / discharging correspondence relationship function causes the battery required power to be 0. In this case, the vehicle body controller 7 controls the fuel cell 2 so that the storage battery 3 is not charged or discharged. The lower limit difference ΔSOC1 and the upper limit difference ΔSOC2 are each set appropriately in advance.

[0056] For example, the vehicle body controller 7 stores a charge capacity conversion table that is appropriately set and created in advance and that converts the output voltage of the storage battery 3 into the charge capacity of the storage battery 3, and the vehicle body controller 7 determines the charge capacity of the storage battery 3 by referring to the charge capacity conversion table from the output voltage of the storage battery 3 measured by the BT voltmeter. Alternatively, for example, the vehicle body controller 7 determines the charge capacity of the storage battery 3 by subtracting the cumulative discharge current amount, which is the cumulative discharge current of the storage battery 3 measured by the BT ammeter from the cumulative charge current amount, which is the cumulative charge current of the storage battery 3 measured by the BT ammeter from the start of use of the storage battery 3 to the present.

[0057] The vehicle body controller 7 determines whether the hydraulic actuator 13 is being driven based on, for example, an operation input to the control lever 9. More specifically, when the control lever 9 is not being operated and is in a so-called neutral position, the vehicle body controller 7 determines that the hydraulic actuator 13 is not being driven. In this case, the vehicle body controller 7 may determine that the hydraulic actuator 13 is not being driven if the control lever 9 remains in the neutral position for a predetermined period of time or longer. When the control lever 9 is being operated, the vehicle body controller 7 determines that the hydraulic actuator 13 is being driven. This makes it possible to provide a hydraulic excavator HS for construction machinery and a control device BC for construction machinery that determine whether the hydraulic actuator 13 is being driven based on an operation input to the control lever 9.

[0058] Alternatively, for example, the vehicle body controller 7 determines whether the hydraulic actuator 13 is being driven based on the operation input of the control lever 9 and the operation input of the lever lock 10. More specifically, when the lever lock 10 is in the unlocked position and the control lever 9 is in the neutral position without being operated, the vehicle body controller 7 determines that the hydraulic actuator 13 is not being driven. In this case, the vehicle body controller 7 may determine that the hydraulic actuator 13 is not being driven if the control lever 9 remains in the neutral position for a predetermined period of time or longer. When the lever lock 10 is in the locked position, the vehicle body controller 7 determines that the hydraulic actuator 13 is not being driven regardless of the input operation of the control lever 9. When the lever lock is in the unlocked position and the control lever 9 is being operated, the vehicle body controller 7 determines that the hydraulic actuator 13 is being driven. This makes it possible to provide a hydraulic excavator HS for construction machinery and a control device BC for construction machinery that determine whether the hydraulic actuator 13 is being driven based on the operation input of the control lever 9 and the operation input of the lever lock 10.

[0059] In this embodiment, the vehicle body controller 7 determines whether the hydraulic actuator 13 is being driven based on the operation input of the operation lever 9 and the operation input of the lever lock 10.

[0060] When the lever lock 10 is in the unlocked position, the vehicle body controller 7 controls the fuel cell 2, the inverter 4, the electric motor 5, the hydraulic pump 6, the unload valve 11, and the control valve 12 in response to the input operation of the accelerator potentiometer 8 and the input operation of the control lever 9, thereby driving the hydraulic actuator 13 and driving the work machine (work attachment 104 in the example shown in FIG. 1 ). More specifically, the vehicle body controller 7 outputs an electric motor rotation speed command value to the inverter 4 so that the rotation speed of the electric motor 5 (the rotation speed of the hydraulic pump 6) corresponds to the operation input (operation amount) by the operator's input operation of the accelerator potentiometer 8, and controls the inverter 4. The inverter 4 converts DC power supplied from at least one of the fuel cell 2 and the storage battery 3 into three-phase AC power, and outputs the three-phase AC power having a current corresponding to the rotation speed represented by the electric motor rotation speed command value to the electric motor 5. The electric motor 5 rotates at the rotation speed and drives the hydraulic pump 6. The vehicle controller 7 outputs a tilt command value, an unloading valve command value, and a control valve command value to the hydraulic pump 6, the unloading valve 11, and the control valve 12, respectively, so that the work machine (the work attachment 104 in the example shown in FIG. 1 ) operates in accordance with the direction and amount of operation of the control lever 9 by the operator, and controls the hydraulic pump 6, the unloading valve 11, and the control valve 12, respectively. The hydraulic pump 6 adjusts its swash plate so that the tilt angle represented by the tilt command value becomes equal to the tilt angle. This adjusts the discharge rate of the hydraulic pump 6. The unloading valve 11 blocks the flow path from the hydraulic pump 6 to the hydraulic oil tank OT, as described above, in accordance with the unloading valve command value. The control valve 12 connects the flow path from the hydraulic pump 6 to the hydraulic actuator 13 and also connects the flow path from the hydraulic actuator 13 to the hydraulic oil tank OT, as described above, in accordance with the control valve command value. This drives the hydraulic actuator 13, and drives the work machine (the work attachment 104 in the example shown in FIG. 1 ).The vehicle controller 7 adds the power consumption CP2 of the auxiliary equipment 1 (1A-1D) to the power consumption CP1 of the electric motor 5, and further adds the charging power DP(ΔSOC) of the storage battery 3 (DP(ΔSOC)>0 in the case of charging, DP(ΔSOC)<0 in the case of discharging) to calculate the power generation (=CP1+CP2+DP(ΔSOC)). The vehicle controller 7 outputs a power generation command value to the fuel cell 2 to control the fuel cell 2 so that the calculated power is generated. The fuel cell 2 generates the power generation command value. Here, in the case of discharging, the charge amount DP(ΔSOC)<0, so the addition of the charge amount DP(ΔSOC) is actually a subtraction. The power consumption CP1 of the electric motor 5 is calculated by multiplying the output current of the inverter 4 measured by the IV ammeter by the output voltage of the inverter 4 measured by the IV voltmeter. The power consumption CP1 of the electric motor 5 may also be calculated based on the discharge pressure, discharge amount, and hydraulic efficiency of the hydraulic pump 6. The power consumption CP2 of the auxiliary equipment 1 (1A to 1D) is calculated by calculating the sum of the first auxiliary equipment power consumption CP2A, which is calculated by multiplying the input current of the first auxiliary equipment 1A measured by the first auxiliary equipment ammeter by the input voltage of the first auxiliary equipment 1A measured by the first auxiliary equipment voltmeter; the second auxiliary equipment power consumption CP2B, which is calculated by multiplying the input current of the second auxiliary equipment 1B measured by the second auxiliary equipment ammeter by the input voltage of the second auxiliary equipment 1B measured by the second auxiliary equipment voltmeter; the third auxiliary equipment power consumption CP2C, which is calculated by multiplying the input current of the third auxiliary equipment 1C measured by the third auxiliary equipment ammeter by the input voltage of the third auxiliary equipment 1C measured by the third auxiliary equipment voltmeter; and the fourth auxiliary equipment power consumption CP2D, which is calculated by multiplying the input current of the fourth auxiliary equipment 1D measured by the fourth auxiliary equipment ammeter by the input voltage of the fourth auxiliary equipment 1D measured by the fourth auxiliary equipment voltmeter.

[0061] On the other hand, when the operator has not input the control lever 9 and the control lever 9 is in the neutral position, and when the lever lock 10 is in the locked position, the vehicle body controller 7 outputs an electric motor rotation speed command value, an unload valve command value, and a control valve command value to the inverter 4, the unload valve 11, and the control valve 12, respectively, to stop the drive of the hydraulic actuator 13, thereby controlling the inverter 4, the unload valve 11, and the control valve 12, respectively. The inverter 4 stops its output, thereby stopping the drive of the electric motor 5 and the hydraulic pump 6. The unload valve 11 connects the flow path from the hydraulic pump 6 to the hydraulic oil tank OT in accordance with the unload valve command value, as described above. The control valve 12 blocks the flow path from the hydraulic pump 6 to the hydraulic actuator 13 in accordance with the control valve command value, as described above. This stops the drive of the hydraulic actuator 13, and the drive of the work machine (the work attachment 104 in the example shown in FIG. 1 ) is stopped. In this embodiment, after the start of the construction machine (a hydraulic excavator in the example shown in FIG. 1 ) HS and when the hydraulic actuator 13 is not being driven, the vehicle body controller 7 controls the fuel cell 2 to generate power at a minimum output, and controls the electric motor 5 so that the electric motor 1 (1A-1D) consumes surplus power calculated based on the minimum generated power generated by the fuel cell 2, the charging power of the storage battery 3 (including the case where the charging power is 0), and the power consumption of the auxiliary equipment 1 (1A-1D) when the auxiliary equipment 1 (1A-1D) is controlled at a target value. More specifically, in this example, after the start of the hydraulic excavator HS and when the hydraulic actuator 13 is not being driven, if the charging rate of the storage battery 3 exceeds an upper limit, the vehicle body controller 7 calculates the surplus power by subtracting the power consumption from the minimum generated power.

[0062] More specifically, the vehicle body controller 7 compares the minimum power generation with the power consumption. If the comparison shows that the minimum power generation exceeds the power consumption, there is surplus power. Therefore, the vehicle body controller 7 calculates the charge capacity of the storage battery 3 to determine the state of charge of the storage battery 3 and determines whether the calculated state of charge of the storage battery 3 exceeds the upper limit. If the determination shows that the state of charge of the storage battery 3 exceeds the upper limit, the vehicle body controller 7 calculates the surplus power by subtracting the power consumption from the minimum power generation. The vehicle body controller 7 controls the electric motor 5 so that the calculated surplus power is consumed by the electric motor 5. That is, the vehicle body controller 7 calculates the rotation speed of the electric motor 5 that can consume the calculated surplus power, outputs a power generation command value to the fuel cell 2 so that the fuel cell 2 generates the minimum power generation, and controls the fuel cell 2. The vehicle body controller 7 also outputs a motor rotation speed command value to the inverter 4 so that the calculated rotation speed of the electric motor 5 (the rotation speed of the hydraulic pump 6) is reached. As a result, the electric motor 5 rotates at the rotational speed via the inverter 4, and consumes surplus power by driving the hydraulic pump 6. The hydraulic oil discharged from the hydraulic pump 6 flows to the hydraulic oil tank OT via the unload valve 11, but the hydraulic actuator 13 is not driven because the flow path from the hydraulic pump 6 to the hydraulic actuator 13 is blocked. In this way, a load for driving the hydraulic pump 6 is applied to the electric motor 5 while the hydraulic actuator 13 is not driven, so surplus power can be consumed more efficiently. On the other hand, if the result of the comparison shows that the minimum power generation is equal to or less than the power consumption, there is no surplus power and the fuel cell 3 needs to generate power at or above the minimum power generation power. Therefore, the vehicle body controller 7 does not drive the electric motor 5, but outputs a power generation command value to the fuel cell 2 to generate power equivalent to the power consumption, and controls the fuel cell 2.

[0063] The rotation speed N [rpm] of the electric motor 5 required to consume the surplus power PWs is calculated as N = ω × 60 / (2 × π) when the angular frequency is ω [rad / s], and the angular frequency ω [rad / s] is calculated as ω = PWs / Tq when the torque of the hydraulic pump 6 is Tq [Nm], and the torque Tq [Nm] of the hydraulic pump 6 is calculated as Tq = p × Q / (2 × π) when the discharge pressure of the hydraulic pump 6 is p [MPa] and the minimum displacement command value of the hydraulic pump 6 is Q [cc / rev]. Therefore, the rotation speed N [rpm] of the electric motor 5 is calculated as N = (PWs / (p × Q)) × 60.

[0064] The surplus power may be set as an output limit value of the electric motor 5, and the rotation speed of the electric motor 5 may be controlled to limit the output current of the electric motor 6, thereby consuming the surplus power.

[0065] In addition to controlling the rotation speed of the electric motor 5, the vehicle controller 7 may also output an unload valve command value to the unload valve 11 so that the unload valve 11 reduces the opening of the flow path connecting the hydraulic pump 6 to the hydraulic oil tank OT, thereby controlling the opening of the flow path to be small and increasing the load on the electric motor 5 that drives the hydraulic pump 6, thereby consuming surplus electricity.

[0066] The vehicle body controller 7 corresponds to an example of a control unit that controls the hydraulic actuator, the hydraulic pump, the electric motor, the fuel cell, and the storage battery.

[0067] Next, the operation of this embodiment will be described. Fig. 5 is a flowchart showing the operation of the control device for the construction machine regarding the second accessory. Fig. 6 is a flowchart showing the operation of the control device for the construction machine regarding the consumption of surplus power.

[0068] The hydraulic excavator HS equipped with the construction machine control device BC is started by the operator operating the ignition key or ignition button, and operates the second accessory 1B as follows.

[0069] In FIG. 5, the vehicle controller 7 of the control device BC measures the temperature of the storage battery 3 using the BT thermometer and stores it (S1).

[0070] Next, the vehicle body controller 7 determines whether the measured temperature of the storage battery 3 is equal to or lower than the lower limit temperature (S3). If the result of this determination is that the temperature of the storage battery 3 is equal to or lower than the lower limit temperature (Yes), the vehicle body controller 7 controls the second fan 23B to stop blowing air from the second fan 23B (S5), controls the heating unit 24B to heat the fluid (S6), and then returns to step S1. If the result of the determination is that the temperature of the storage battery 3 is not equal to or lower than the lower limit temperature (No), the vehicle body controller 7 controls the heating unit 24B to stop heating (S3), and controls the second fan 23B to blow air (S4), and then returns to step S1.

[0071] When returning the process to step S1, the vehicle body controller 7 may execute a wait process for a predetermined time that has been set in advance, and then return the process to step S1.

[0072] The second accessory 1B is controlled in this manner after the hydraulic excavator HS is started. Note that each of the steps S1 to S6 is completed when the power of the hydraulic excavator HS is stopped (operation is terminated).

[0073] After startup, the hydraulic excavator HS equipped with the construction machinery control device BC operates as follows regarding surplus power.

[0074] 6, the vehicle body controller 7 of the control device BC determines whether the hydraulic actuator 13 is being driven based on the operation input of the operation lever 9 and the operation input of the lever lock 10 (S11). If the result of this determination is that the hydraulic actuator 13 is being driven (Yes), the vehicle body controller 7 returns the process to step S11, and if the result of the determination is that the hydraulic actuator 13 is not being driven (No), the vehicle body controller 7 next executes step S12. Therefore, the vehicle body controller 7 repeatedly executes step S11 until it determines that the hydraulic actuator 13 is not being driven.

[0075] In step S12, the vehicle body controller 7 compares the minimum power generation with the power consumption. If the comparison shows that the minimum power generation exceeds the power consumption (power consumption exceeded), the vehicle body controller 7 calculates the charge capacity of the storage battery 3 to determine the charging rate of the storage battery 3, and determines whether the calculated charging rate of the storage battery 3 exceeds the upper limit (S13). If the result of this determination is that the charging rate does not exceed the upper limit (No), the vehicle body controller 7 returns the processing to step S11. On the other hand, if the result of the determination is that the charging rate exceeds the upper limit (Yes), the vehicle body controller 7 calculates the surplus power by subtracting the consumed power from the minimum generated power (S14), calculates the rotation speed of the electric motor 5 that can consume the calculated surplus power (S15), outputs a power generation command value to the fuel cell 2 so as to generate the minimum generated power, controls the fuel cell 2, outputs a motor rotation speed command value to the inverter 4 so as to achieve the calculated rotation speed of the electric motor 5 (rotation speed of the hydraulic pump 6), controls the inverter 4 (S16), and returns the processing to step S11.

[0076] If the result of the comparison shows that the minimum power generation is equal to or less than the power consumption (equal to or less than the power consumption), the vehicle controller 7 does not drive the electric motor 5, outputs a power generation command value to the fuel cell 2 so as to generate power equivalent to the power consumption, controls the fuel cell 2 (S17), and returns the process to step S11.

[0077] When returning the process to step S11, the vehicle body controller 7 may execute a wait process for a predetermined time that has been set in advance, and then return the process to step S11.

[0078] The hydraulic excavator HS equipped with the construction machinery control device BC operates in this manner with respect to surplus power after startup. Note that each of the processes S11 to S17 is terminated when the power of the hydraulic excavator HS is stopped (operation is terminated).

[0079] As explained above, when the construction machinery hydraulic excavator HS and the construction machinery control device BC mounted thereon control the fuel cell 2 at minimum output, the excess power that is not consumed by the storage battery 3 and the auxiliary equipment 1 (1A to 1D) is consumed by the electric motor 5. Therefore, even when the fuel cell 2 is operated at minimum output, the excess power can be consumed while the storage battery 3 and the auxiliary equipment 1 (1A to 1D) are operated appropriately.

[0080] The hydraulic excavator HS and the control device BC of the construction machinery can consume surplus power so that the storage battery is not overcharged beyond the upper limit.

[0081] The hydraulic excavator HS of the construction machine and the control device BC of the construction machine heat the fluid of the second auxiliary machine 1B using the heating section 24B as needed, so that the storage battery 3 can be operated at an appropriate temperature without being overcooled.

[0082] The hydraulic excavator HS of the construction machine and the control device BC of the construction machine control the electric motor 5 so that the rotation speed corresponds to the surplus power, so that the surplus power can be consumed by the electric motor 5 appropriately.

[0083] In the above-described embodiment, the storage battery 3 is charged and discharged in accordance with the charge-discharge correspondence function shown in FIG. 4 (first mode of charging and discharging), but the storage battery 3 may also be charged and discharged in accordance with the charge map and discharge map shown in FIG. 7 (second mode of charging and discharging).

[0084] Fig. 7 is a diagram for explaining a second mode of charging and discharging of the storage battery in the control device for the construction machine. Fig. 7A shows a charging map showing the correspondence relationship between the storage battery rate, temperature, and required power of the storage battery when charging the storage battery, and Fig. 7B shows a discharging map showing the correspondence relationship between the storage battery rate, temperature, and required power of the storage battery when discharging the storage battery.

[0085] The power that the storage battery 3 can charge and discharge normally varies depending on the temperature of the storage battery 3. For this reason, in the charging and discharging of this second mode, a charging map and a discharging map are used that show the relationship between the state of charge of the storage battery 3, the temperature of the storage battery 3, and the power required by the storage battery. The charging map is used when charging the storage battery 3, and the discharging map is used when discharging the storage battery 3. For example, the charging map CM shown in FIG. 7A and the discharging map CM shown in FIG. 7B are each a two-dimensional lookup table (two-dimensional matrix) that includes rows representing different states of charge [%] of the storage battery 3 and columns representing different temperatures [°C] of the storage battery 3, and registers the power required by the storage battery corresponding to the state of charge [%] of the row and the temperature [°C] of the column in the intersection area between the row and the column. In the example shown in Fig. 7A, charging and discharging are not possible at temperatures below temperature Temp_A [°C], and charging and discharging are not possible at temperatures above temperature Temp_B [°C]. However, the storage battery 3 can be charged and discharged in a temperature range equal to or higher than temperature Temp_A and equal to or lower than temperature Temp_B. The charging rate SOC_A [%] is smaller than the charging rate SOC_B [%] ((charging rate SOC_A)<(charging rate SOC_B)), the charging rate SOC_C [%] is smaller than the charging rate SOC_D [%] ((charging rate SOC_C)<(charging rate SOC_D)), and the charging rate SOC_B is smaller than the charging rate SOC_C ((charging rate SOC_B)<(charging rate SOC_C). In the charging map shown in Fig. 7A, the power required by the storage battery DP(Temp_k, SOC_k) is represented by shading, and the darker the shading, the greater the power required by the storage battery DP(Temp_k, SOC_k) (>0). Therefore, the storage battery 3 is charged at a larger charge amount DP(Temp_k, SOC_k) (>0). In the discharge map shown in FIG. 7B, the power required by the storage battery DP(Temp_k, SOC_k) is represented by shading; the darker the shading, the larger the absolute value of the power required by the storage battery DP(Temp_k, SOC_k) (<0), and therefore the storage battery 3 is discharged at a larger discharge amount |DP(Temp_k, SOC_k)|. In FIGS. 7A and 7B, the power required by the storage battery DP(Temp_k, SOC_k)=0 indicates no charging or discharging.

[0086] In this second mode of charging and discharging, the vehicle body controller 7 first calculates the state of charge SOC_k [%] of the storage battery 3 from the charge capacity of the storage battery 3 calculated in the same manner as in the above-described embodiment. Next, the vehicle body controller 7 references the charging map CM in FIG. 7A and the discharging map DM in FIG. 7B to select a battery power requirement DP(Temp_k, SOC_k) corresponding to the temperature Tenm_k [°C] of the storage battery 3 measured by the BT thermometer and the calculated state of charge SOC_k of the storage battery 3. If the selected battery power requirement DP(Temp_k, SOC_k) is positive, this indicates that the storage battery 3 is being charged, and the vehicle body controller 7 controls the fuel cell 2 so that the storage battery 3 is charged with the selected battery power requirement DP(Temp_k, SOC_k). If the selected battery required power DP(Temp_k, SOC_k) is negative, this indicates discharging of the battery 3, and the vehicle body controller 7 controls the fuel cell 2 so that the battery 3 discharges at the selected battery required power |DP(Temp_k, SOC_k)|. If the selected battery required power DP(Temp_k, SOC_k) is 0, the vehicle body controller 7 controls the fuel cell 2 so that the battery 3 does not charge or discharge.

[0087] In this second mode of charging and discharging, in the control of the second accessory 1B described above, the lower limit temperature is the temperature Temp_A.

[0088] In the above description, the first to fourth auxiliaries 1A-1D are each equipped with a first to fourth fan 22A-22D that is controlled independently. However, if each of the first to fourth auxiliaries 1A-1D has only one fan, the vehicle body controller 7 may control the first to fourth auxiliaries 1A-1D as follows: When the temperature of the storage battery 3 measured by the BT thermometer is equal to or lower than the lower limit temperature Temp_A, the vehicle body controller 7 controls the one fan to stop blowing air, and controls the heating unit 24B to heat the fluid. When the temperature of the storage battery 3 measured by the BT thermometer is not equal to or lower than the lower limit temperature Temp_A, the vehicle body controller 7 controls the heating unit 24B to stop heating, and controls the one fan at the larger (faster) rotation speed selected from the second fan rotation speed determination table and the third fan rotation speed determination table.

[0089] Furthermore, in the above-described embodiment, an unloading valve 11 and a control valve 12 are provided between the hydraulic pump 6 and the hydraulic actuator 13, and the hydraulic oil when the electric motor 5 is driven by consuming surplus power is caused to flow into the hydraulic oil tank OT via the unloading valve 11 without bypassing the hydraulic actuator 13 and driving the hydraulic actuator 13. However, this is not limited to this, and other methods may be used, for example, the configuration shown in FIG. 8, in which the hydraulic oil when the electric motor 5 is driven by consuming surplus power is caused to flow into the hydraulic oil tank OT without bypassing the hydraulic actuator 13 and driving the hydraulic actuator 13.

[0090] Fig. 8 is a block diagram showing the configuration of a construction machine control device in a modified embodiment. As shown in Fig. 8, the construction machine control device BCa in this modified embodiment includes an auxiliary device 1 (1A to 1D), a fuel cell 2, a storage battery 3, an inverter 4, an electric motor 5, a hydraulic pump 6, a vehicle controller 7, an accelerator potentiometer 8, an operating lever 9, a lever lock 10, a control valve 16, and a cut valve 17. The accessories 1 (1A to 1D), fuel cell 2, storage battery 3, inverter 4, electric motor 5, hydraulic pump 6, vehicle controller 7, accelerator potentiometer 8, operating lever 9 and lever lock 10 in the construction machinery control device BCa of these modified embodiments are the same as the accessories 1 (1A to 1D), fuel cell 2, storage battery 3, inverter 4, electric motor 5, hydraulic pump 6, vehicle controller 7, accelerator potentiometer 8, operating lever 9 and lever lock 10 in the construction machinery control device BC of the above-mentioned embodiment, except that the vehicle controller 7 controls the control valve 16 and cut valve 17 instead of the unload valve 11 and control valve 12, and therefore their description will be omitted.

[0091] The control valve 16 is electrically connected to the vehicle body controller 7 and is a valve that switches the flow path of the hydraulic oil discharged from the hydraulic pump 6 in accordance with the control of the vehicle body controller 7. When the hydraulic actuator 13 is driven, the control valve 16 connects a flow path from the hydraulic pump 6 to the hydraulic actuator 13 in accordance with the control of the vehicle body controller 7, and also connects a flow path from the hydraulic actuator 13 to the hydraulic oil tank OT. When the hydraulic actuator 13 is not driven, the control valve 16 blocks the flow path from the hydraulic pump 6 to the hydraulic actuator 13 and connects the flow path from the hydraulic pump 6 to the cut valve 17 in accordance with the control of the vehicle body controller 7.

[0092] The cut valve 17 is electrically connected to the vehicle body controller 7 and is a valve that switches the flow path of the hydraulic oil discharged from the hydraulic pump 6 in accordance with the control of the vehicle body controller 7. When the hydraulic actuator 13 is not being driven, the cut valve 17 connects the flow path from the hydraulic pump 6 to the hydraulic oil tank OT via the control valve 16 in accordance with the control of the vehicle body controller 7. When the hydraulic actuator 13 is being driven, the cut valve 17 blocks the flow path to the hydraulic oil tank OT in accordance with the control of the vehicle body controller 7.

[0093] In order to express the present invention, the present invention has been properly and sufficiently described above through the embodiments with reference to the drawings, but it should be recognized that those skilled in the art can easily change and / or improve the above-mentioned embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that causes departure from the scope of the claims described in the claims, such changes or improvements are interpreted as being included in the scope of the claims. [Explanation of symbols]

[0094] HS Construction machinery (hydraulic excavators as an example) BC Construction machinery control device FT fuel tank OT hydraulic oil tank 1 Auxiliary equipment 1A First auxiliary engine 1B Second auxiliary engine 1C 3rd auxiliary engine 1D 4th auxiliary engine 2 fuel cell 3. Storage battery 4 inverters 5 Electric motor 6 Hydraulic pump 7 Body Controller 8 Accelerator Potentiometer 9 Operating lever 10 Lever lock 11 Unloading valve 12 Control valve 13 Hydraulic Actuator 21A Hydraulic System 21B High voltage equipment 21C FC high voltage equipment 21D FC 22A~22D 1st to 4th radiators 23A~23D 1st to 4th fans 24B Heating section 25B~25C 2nd to 4th auxiliary pumps 26B to 26D Second to fourth flow path members 104 Work machines (one example of which is work attachments)

Claims

1. a hydraulic actuator that drives a work machine to perform a predetermined task; a hydraulic pump that drives the hydraulic actuator; an electric motor that drives the hydraulic pump; a fuel cell that generates electricity through an oxidation-reduction reaction between a fuel and an oxidant; a storage battery that charges and discharges the power generated by the fuel cell; an auxiliary machine that consumes electric power when at least one of the hydraulic actuator, the hydraulic pump, the electric motor, the fuel cell, and the storage battery is used as a main machine; and A control device for a construction machine comprising a control unit that controls each of the hydraulic actuator, the hydraulic pump, the electric motor, the fuel cell, and the storage battery, the electric motor is supplied with power from at least one of the fuel cell and the storage battery; the auxiliary equipment is supplied with power from at least one of the fuel cell and the storage battery, the control unit controls the fuel cell to generate power at a minimum output when the hydraulic actuator is not being driven after the construction machine has been started, and controls the electric motor to consume surplus power calculated based on the minimum generated power generated by the fuel cell, the charging power of the storage battery, and the power consumption of the auxiliary equipment when the auxiliary equipment is controlled at a target value; Construction machinery control device.

2. When the charging rate of the storage battery exceeds an upper limit value, the control unit calculates the surplus power by subtracting the consumed power from the minimum generated power. The control device for a construction machine according to claim 1.

3. The auxiliary equipment is an auxiliary equipment for a storage battery when the storage battery is included as a main equipment, and includes: a heating unit that heats a fluid; a radiator that is connected to the heating unit and exchanges heat between the fluid and an ambient environment; a fan that blows air to the radiator to cool the fluid in the radiator; a flow path member that forms a flow path from the radiator back to the radiator via the heating unit and the storage battery, and through which the fluid flows; and a pump that is interposed in the flow path member and returns the fluid from the radiator to the radiator via the heating unit and the storage battery, the control unit controls the fan to stop blowing air and controls the heating unit to heat the fluid when the temperature of the storage battery is equal to or lower than a lower limit temperature. The control device for a construction machine according to claim 1.

4. further comprising an operation lever that receives operation input for the work machine, the control unit determines whether the hydraulic actuator is being driven based on an operation input of the operation lever. The control device for a construction machine according to claim 1.

5. a lever lock that switches between valid and invalid input operations of the operation lever; the control unit determines whether the hydraulic actuator is being driven based on an operation input of the operating lever and an operation input of the lever lock. The control device for a construction machine according to claim 4.

6. the control unit controls the electric motor so that the rotation speed corresponds to the surplus power. The control device for a construction machine according to claim 1.

7. A construction machine equipped with the control device for a construction machine according to any one of claims 1 to 6.

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