JP6356956B2 - Hybrid construction machine - Google Patents

Description

  The present invention relates to a hybrid construction machine including a power storage device that supplies electric power to an electric motor such as a motor and an inverter.

  In recent years, hybrid and electric vehicles are widely used in automobiles from the viewpoint of energy saving, and hybrids are also being promoted in construction machines. In general, a construction machine such as a hydraulic excavator that is driven by a hydraulic system drives a hydraulic pump that enables a maximum load work so that it can handle all work from light load work to heavy load work. And a large engine.

  However, heavy-duty work such as heavy excavation work that frequently digs and loads earth and sand in construction machinery is a part of the whole work, and the engine capacity is low during light-load work such as horizontal pulling to level the ground. It will remain. This is one of the factors that make it difficult to reduce the fuel consumption of the hydraulic excavator (hereinafter sometimes abbreviated as fuel efficiency). In view of this point, a hybrid construction machine is known in which the engine is downsized to reduce fuel consumption, and the output shortage due to the downsizing of the engine is assisted by the output of the power storage device and the electric motor. . Electric devices such as power storage devices and electric motors that constitute this hybrid construction machine require appropriate temperature control for thermal protection of the drive circuit and high-efficiency operation.

  In particular, the power storage device has an upper limit temperature that can be used without current limitation, while the output of the power storage device decreases at a low temperature. Therefore, in order to use the power storage device without incurring such a decrease in the output of the power storage device. The power storage device needs to be heated to a predetermined temperature or higher. Therefore, when the temperature of the power storage device is lower than a preset temperature, the engine is operated to perform a warm-up operation, and the motor generator is operated to charge / discharge the power storage device, thereby generating heat in the power storage device. A warming-up method for a construction machine has been proposed (see, for example, Patent Document 1).

JP 2010-127271 A

  However, in the warming-up method of the conventional hybrid construction machine disclosed in Patent Document 1 described above, the power storage device is warmed using self-heating due to charging / discharging of the power storage device. If it is smaller, it takes time for the power storage device to reach a predetermined temperature. Therefore, since there is a possibility that the output required to operate the construction machine during that time may not be secured, there is a concern that work by the construction machine cannot be started immediately.

  On the other hand, if the current flowing through the power storage device is large, the time required for the warm-up operation of the power storage device can be shortened. However, the load on the power storage device increases as the current flowing through the power storage device increases, so the power storage device deteriorates. It becomes easy to do. This may cause inconveniences such as an increase in the replacement frequency of the power storage device.

  The present invention has been made in view of such a state of the art, and an object of the present invention is to provide a hybrid construction machine that can quickly warm up the power storage device and improve the life of the power storage device. is there.

In order to achieve the above object, a hybrid construction machine according to the present invention includes a prime mover, a motor generator that assists and generates power for the prime mover, and a power storage that transfers power between the motor generator. And a control device that controls charging / discharging of the power storage device, and a voltage measuring unit that measures a voltage of the power storage device, wherein the control device determines a charge / discharge state of the power storage device. Based on the voltage determined by the state determination unit, the voltage measurement unit, the charge / discharge state of the power storage device determined by the charge / discharge state determination unit, and the predetermined upper and lower limit values of the voltage of the power storage device, A calculation unit that calculates a current for charging and discharging the power storage device, and a current control unit that controls a current flowing through the power storage device during a warm-up operation of the power storage device according to the current calculated by the calculation unit; Including The calculation unit calculates a current such that a deviation between a voltage measured by the voltage measurement unit and a predetermined upper limit value of the voltage of the power storage device is zero when the power storage device is charged, and discharges the power storage device. Sometimes, a current is calculated such that a deviation between a voltage measured by the voltage measurement unit and a predetermined lower limit value of the voltage of the power storage device is zero, and the current control unit A warm-up operation determination unit that determines whether or not to perform a warm-up operation of the power storage device by comparing an output required of the power storage device with an allowable output of the power storage device; It is characterized in that the current flowing through the power storage device is controlled when it is determined to perform the warm-up operation of the device .

  In the present invention configured as described above, the control device performs the warm-up operation of the power storage device by charging and discharging the power storage device in order to solve the shortage of output of the power storage device due to low temperature. At this time, even if the current flowing through the power storage device is increased so that the warm-up operation time of the power storage device can be shortened, the voltage measured by the voltage sensor, the charge / discharge state of the power storage device determined by the charge / discharge state determination unit The current flowing through the power storage device in accordance with the state and the predetermined upper and lower limit values of the voltage of the power storage device is controlled by the current control unit to an appropriate range for charging and discharging the power storage device. It is possible to prevent the battery from becoming a state or an overdischarged state, and the burden on the power storage device accompanying an increase in the current flowing through the power storage device can be reduced. Accordingly, the power storage device can be quickly warmed up and the life of the power storage device can be improved.

  The hybrid construction machine according to the present invention is the hybrid construction machine according to the present invention, wherein the current control unit causes the current that is calculated by the calculation unit to be multiplied by a coefficient that is greater than 0 and less than 1 and that flows through the power storage device. It is characterized by setting as. With this configuration, the power storage device can be warmed up in consideration of the relationship between the warm-up time of the power storage device and the deterioration of the power storage device by appropriately adjusting a coefficient to be multiplied by the current calculated by the calculation unit. Therefore, the operator's request regarding the power storage device can be taken in well.

  In the hybrid construction machine according to the present invention as set forth in the invention, the current control unit compares the current calculated by the calculation unit with a limit value of a current for charging and discharging the power storage device. The current flowing through the apparatus is set to be equal to or less than the limit value. With this configuration, since a limit value is set for the current for charging and discharging the power storage device, it is possible to prevent the current flowing to the power storage device from becoming excessive even if the current flowing to the power storage device is increased. it can. Thus, the power storage device can be efficiently charged and discharged in a stable state.

  Further, the hybrid construction machine according to the present invention includes a temperature measurement unit that measures the temperature of the power storage device in the invention, and the current control unit is based on the temperature measured by the temperature measurement unit. A warm-up operation determination unit that determines whether or not to perform the warm-up operation of the power storage device, and a current that flows to the power storage device when the warm-up operation determination unit determines that the warm-up operation of the power storage device is performed It is characterized by control.

  In the present invention configured as described above, the warm-up operation determination unit determines whether or not to perform the warm-up operation of the power storage device based on the temperature measured by the temperature measurement unit, and the current control unit performs the warm-up operation. By controlling the current flowing through the power storage device after receiving the determination result of the operation determination unit, excessive charging / discharging of the power storage device can be avoided. For this reason, for example, when the temperature of the power storage device is high and sufficient output can be obtained from the power storage device, the power storage device does not need to be warmed up. The life of the power storage device can be further improved.

  Further, in the hybrid construction machine according to the present invention, in the invention, the current control unit compares the output required of the power storage device with respect to the operation output of the vehicle body and the allowable output of the power storage device. A warm-up operation determination unit that determines whether or not to perform the warm-up operation of the power storage device, and a current that flows to the power storage device when the warm-up operation determination unit determines that the warm-up operation of the power storage device is performed. It is characterized by control.

  In the present invention configured as described above, if the output required of the power storage device with respect to the operation output of the vehicle body is less than or equal to the allowable output of the power storage device, the allowable output can be taken out to sufficiently operate the vehicle body. . Therefore, the warm-up operation determination unit determines whether or not to perform the warm-up operation of the power storage device by comparing the output required for the power storage device with respect to the operation output of the vehicle body and the allowable output of the power storage device. The unit can avoid excessive charging / discharging of the power storage device by controlling the current flowing through the power storage device after receiving the determination result of the warm-up operation determination unit. Thereby, the frequency | count of use of the electrical storage apparatus by warm-up operation can be reduced, and the lifetime of an electrical storage apparatus can be improved more.

  In the hybrid construction machine according to the present invention, in the invention, the allowable output of the power storage device is a product of a voltage of the power storage device measured by the voltage measurement unit and a current calculated by the calculation unit. It is characterized by being calculated. According to this configuration, the measurement result of the voltage sensor obtained in the process of current control by the current control unit and the calculation result of the calculation unit can be effectively used for calculation of the allowable output of the power storage device. It can be easily obtained.

  The hybrid construction machine according to the present invention is characterized in that, in the above invention, the control device includes a limiting unit that limits the operation of the vehicle body based on an allowable output of the power storage device. With this configuration, the operation of the vehicle body is restricted by the restriction unit in consideration of the allowable output of the power storage device, so that the motor generator can be powered by the prime mover in order to obtain the allowable output necessary for operating the vehicle body. Since excessive warm-up operation in which (drive) / regeneration (power generation) is repeated rapidly is not performed, the fuel consumption of the prime mover associated with such warm-up operation can be suppressed.

  The hybrid construction machine according to the present invention may further include an output setting unit that sets an operation output of a vehicle body in the invention, and the limiting unit is connected to the power storage device with respect to the output set by the output setting unit. When the required output is larger than the allowable output of the power storage device, the vehicle body operation output is set to be equal to or lower than a preset output with respect to the allowable output of the power storage device, and the vehicle body operation is limited. Yes. With this configuration, when the operator sets the vehicle operation output to be large by the output setting unit, the allowable output of the power storage device can be obtained as the output required for the vehicle operation output by the warm-up operation. Although the operation of the vehicle body is appropriately regulated by the restriction unit, the operator can operate the vehicle body within the allowable output range of the power storage device, so the construction machine can be operated even during the warm-up operation of the power storage device. Therefore, it is possible to sufficiently ensure the convenience of the operator who performs the work.

  In addition, the hybrid construction machine according to the present invention is characterized in that, in the above invention, when the operation of the vehicle body is restricted by the restriction unit, a display device that displays information related to the operation of the vehicle body is provided. If comprised in this way, the operator can grasp | ascertain easily that the operation | movement of a vehicle body is restrict | limited by the temperature of an electrical storage apparatus by confirming the information displayed on the display apparatus. Accordingly, it is possible to take appropriate measures such as the operator interrupting the work and waiting until the warm-up operation of the power storage device is completed.

  In the hybrid construction machine according to the present invention, the hydraulic pump connected to the motor generator, the hydraulic actuator driven by the pressure oil discharged from the hydraulic pump, and the hydraulic actuator And a valve device that controls a flow rate and a direction of the pressure oil to be operated, and when the control device determines that the warm-up operation determination unit performs the warm-up operation of the power storage device, the hydraulic pump, the hydraulic actuator And at least one of the valve devices is operated to discharge the power storage device.

  In the present invention configured as described above, since the prime mover and the hydraulic pump serve as an electrical load of the motor generator, at least one of the hydraulic pump, the hydraulic actuator, and the valve device is operated, and the motor generator generates power for driving the hydraulic pump. By increasing the power consumption of the machine, the energy stored in the power storage device can be efficiently released as discharge energy.

  According to the hybrid construction machine of the present invention, the power storage device can be quickly warmed up and the life of the power storage device can be improved. Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

It is a figure which shows the structure of the hybrid type hydraulic shovel mentioned as one Embodiment of the hybrid type construction machine which concerns on this invention. It is a figure explaining the structure of the principal part of the hybrid type hydraulic shovel which concerns on this embodiment. It is a figure which shows the structure of the temperature control apparatus which concerns on this embodiment. It is a figure which shows the relationship between the charging rate (SOC) of the electrical storage apparatus which concerns on this embodiment, and an allowable output for every temperature of an electrical storage apparatus. It is a figure which shows the structure of the controller which concerns on this embodiment. It is a figure explaining the vehicle body request | requirement output used for control of the controller which concerns on this embodiment. It is a figure explaining the other example of the vehicle body request | requirement output used for control of the controller which concerns on this embodiment. It is a flowchart explaining the operation | movement of the warming-up operation | movement of the electrical storage apparatus by the controller which concerns on this embodiment. It is a figure explaining the limiting value of the current which charges / discharges the power storage device according to the present embodiment. It is a flowchart explaining the other example of operation | movement of the warming-up operation | movement of the electrical storage apparatus by the controller which concerns on this embodiment. It is a figure which shows the time transition of the electric current of the electrical storage apparatus, voltage, and a charging rate (SOC) when the electrical storage apparatus which concerns on this embodiment is warmed up. It is a figure which shows the time transition of the temperature of an electrical storage apparatus when an electrical storage apparatus which concerns on this embodiment is warmed up, and allowable output. It is a figure which shows the relationship between the allowable output of the electrical storage apparatus memorize | stored in the controller which concerns on this embodiment, and the operation output of a vehicle body. It is a figure which shows the other example of the relationship between the allowable output of the electrical storage apparatus memorize | stored in the controller which concerns on this embodiment, and the operation output of a vehicle body.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the hybrid type construction machine which concerns on this invention is demonstrated based on figures.

  FIG. 1 is a diagram illustrating a configuration of a hybrid hydraulic excavator cited as an embodiment of a hybrid construction machine according to the present invention, and FIG. 2 is a diagram illustrating a configuration of a main part of the hybrid hydraulic excavator according to the present embodiment. is there.

  One embodiment of a hybrid construction machine according to the present invention is applied to, for example, a hybrid hydraulic excavator (hereinafter referred to as a hydraulic excavator for convenience) as shown in FIG. This hydraulic excavator is attached to a traveling body 100, a revolving body 110 provided on the traveling body 100 via a revolving frame 111 so as to be able to swivel, and mounted in front of the revolving body 110, and is rotated in the vertical direction. And a front work machine 70 for performing excavation and the like.

  The front work machine 70 includes a boom 71 that is pivotally attached to the revolving frame 111 and pivots in the vertical direction, an arm 72 that is pivotally attached to the tip of the boom 71, and the arm 72. The bucket 73 is rotatably attached to the tip of the bucket. Further, the front work machine 70 connects the swing body 110 and the boom 71, connects the boom cylinder 71a that rotates the boom 71 by expanding and contracting, the boom 71 and the arm 72, and expands and contracts the arm 72. The arm cylinder 72a for rotating the bucket 73 and the bucket cylinder 73a for connecting the arm 72 and the bucket 73 and rotating the bucket 73 by expanding and contracting are provided.

  As shown in FIG. 1 and FIG. 2, the revolving body 110 is a driving machine (cabin) 3 provided in the front part on the revolving frame 111 and a prime mover provided in a motor room 112 in the rear part on the revolving frame 111. The engine 1, the governor 7 for adjusting the fuel injection amount of the engine 1, the rotational speed sensor 1 a for detecting the actual rotational speed of the engine 1, the engine torque sensor 1 b for detecting the torque of the engine 1, An assist power generation motor 2 as a motor generator for assisting power generation and generating electric power is provided.

  The assist generator motor 2 is disposed on the drive shaft of the engine 1 and transmits torque to and from the engine 1. The cab 3 includes an output setting unit that sets the operation output of the vehicle body. The output setting unit includes an engine rotation speed adjustment dial 3b that adjusts the rotation speed of the engine 1 and sets the operation output of the vehicle body, for example. Yes. The engine speed adjustment dial 3b is used by the operator in the cab 3 to set the operation output of the vehicle body to “small output” (economy mode suitable for light load work) or “large” according to the work contents. "Output" (power mode suitable for high-load work) is selected.

  Further, the swing body 110 includes an inverter device 9 that controls the number of rotations of the assist power generation motor 2, a power storage device 8 that transfers power to and from the assist power generation motor 2 via the inverter device 9, and the boom described above. And a valve device 12 that controls the flow rate and direction of pressure oil supplied to hydraulic actuators 71a to 73a such as a cylinder 71a, an arm cylinder 72a, and a bucket cylinder 73a.

  A hydraulic system 90 for driving the hydraulic actuators 71 a to 73 a is disposed in the prime mover chamber 112 of the swing body 110. The hydraulic system 90 is connected to the hydraulic pump 5 serving as a hydraulic source that generates hydraulic pressure, the pilot hydraulic pump 6 that generates pilot pressure oil, and the operation unit of the valve device 12 via a pilot pipe P, and And an operation device 4 that enables a desired operation of the actuators 71a to 73a. The operating device 4 is provided in the cab 3 and has an operating lever 4a that is gripped and operated by an operator.

  Further, the swing body 110 adjusts the capacity of the hydraulic pump 5, and adjusts the governor 7 to control the rotational speed of the engine 1 and also controls the inverter device 9 to control the assist generator motor 2. And a controller 11 for controlling torque. The hydraulic pump 5, the hydraulic actuators 71a to 73a, and the valve device 12 constitute a hydraulic circuit. The actual rotational speed of the engine 1 detected by the above-described rotational speed sensor 1a and the engine torque sensor 1b are detected. The torque of the engine 1, the operation amount of the operation lever 4a, and the like are input to the controller 11.

  The hydraulic pump 5 is connected to the engine 1 via the assist power generation motor 2, and the hydraulic pump 5 and the pilot hydraulic pump 6 operate from the hydraulic pump 5 by operating with the driving force of the engine 1 and the assist power generation motor 2. The discharged pressure oil is supplied to the valve device 12, and the pilot pressure oil discharged from the pilot hydraulic pump 6 is supplied to the operating device 4.

  At this time, when an operator in the cab 3 operates the operation lever 4a, the operation device 4 supplies pilot pressure oil corresponding to the operation amount of the operation lever 4a to the operation portion of the valve device 12 via the pilot pipe P. By supplying, the position of the spool in the valve device 12 is switched by the pilot pressure oil, and the pressure oil flowing through the valve device 12 from the hydraulic pump 5 is supplied to the hydraulic actuators 71a to 73a. Thereby, the hydraulic actuators 71 a to 73 a are driven by the pressure oil supplied from the hydraulic pump 5 via the valve device 12.

  The hydraulic pump 5 has, for example, a swash plate (not shown) as a variable displacement mechanism, and controls the discharge flow rate of the pressure oil by adjusting the inclination angle of the swash plate. Hereinafter, although the hydraulic pump 5 will be described as a swash plate pump, the hydraulic pump 5 may be a slant shaft pump or the like as long as it has a function of controlling the discharge flow rate of pressure oil. Although not shown in the drawing, the hydraulic pump 5 includes a discharge pressure sensor that detects the discharge pressure of the hydraulic pump 5, a discharge flow rate sensor that detects the discharge flow rate of the hydraulic pump 5, and an inclination angle sensor that measures the inclination angle of the swash plate. The controller 11 calculates the load of the hydraulic pump 5 by inputting the discharge pressure, the discharge flow rate, and the inclination angle of the swash plate obtained from these sensors.

  The pump capacity adjusting device 10 adjusts the capacity (displacement volume) of the hydraulic pump 5 based on an operation signal output from the controller 11. Specifically, the pump capacity adjusting device 10 includes a regulator 13 that supports the swash plate so as to be tiltable, and an electromagnetic proportional valve 14 that applies a control pressure to the regulator 13 in accordance with a command value of the controller 11. When a control pressure is received from the electromagnetic proportional valve 14, the capacity (displacement volume) of the hydraulic pump 5 is adjusted by changing the inclination angle of the swash plate by this control pressure, and the absorption torque (input) of the hydraulic pump 5 is adjusted. Torque) can be controlled.

  Further, an exhaust gas purification system for purifying exhaust gas discharged from the engine 1 is provided in the exhaust passage of the engine 1, and this exhaust gas purification system is included in the exhaust gas by ammonia generated from urea as a reducing agent. A selective catalytic reduction catalyst (SCR catalyst) 80 for promoting the reduction reaction of nitrogen oxides, a reducing agent adding device 81 for adding urea into the exhaust passage of the engine 1, and urea supplied to the reducing agent adding device 81 And a muffler (silencer) 83 that silences the exhaust sound of the engine 1. Therefore, the exhaust gas of the engine 1 is discharged into the atmosphere through the muffler 83 after the selective catalytic reduction catalyst 80 purifies the nitrogen oxides in the exhaust gas into harmless water and nitrogen.

  Since the assist power generation motor 2, the inverter device 9, and the power storage device 8 described above generate heat as they continue to be used, the revolving unit 110 includes the assist power generation motor 2, the inverter device 9, And the below-mentioned cooling circuit which cools the electrical storage apparatus 8 is provided. Here, since the power storage device 8 has an upper limit temperature that can be used without current limitation, the revolving structure 110 adjusts the temperature of the power storage device 8 so that the temperature of the power storage device 8 does not become excessively high. Is installed.

  FIG. 3 is a diagram showing the configuration of the temperature control device according to the present embodiment.

  As shown in FIG. 3, the temperature adjustment device 20 includes the above-described cooling circuit 21 that circulates a device cooling medium such as cooling water to cool the power storage device 8, and the cooling circuit 21 includes the device cooling medium inside. A liquid pipe 22 that circulates, a pump 23 that circulates an equipment cooling medium in the liquid pipe 22, a water jacket 24 as a heat exchange member that exchanges heat between the power storage device 8 and the equipment cooling medium, and equipment cooling It comprises a radiator 26 that exchanges heat between the medium and the outside air, and these devices are connected in an annular manner in order by a liquid pipe 22. The radiator 26 is provided with a blower fan 27 that takes outside air into the revolving structure 110 and cools the device cooling medium and the like.

  The liquid piping 22 connected to the outlet of the water jacket 24 is provided with a temperature sensor (not shown) such as a thermistor or a thermocouple for measuring the temperature of the equipment cooling medium. The temperature signal of the equipment cooling medium measured by this temperature sensor is output to the controller 11. Here, since the hydraulic excavator is generally used in a place with a lot of dust, it is preferable to use cooling water as a device cooling medium. In addition, the power storage device 8 is preferably covered with a protective cover or the like in order to prevent foreign matter such as dust or water from entering and being damaged.

  The power storage device 8 includes a battery, a capacitor, or the like, and includes, for example, a plurality of battery cells 30 arranged in series along the water jacket 24. These battery cells 30 are connected to the water via a heat conductive sheet 36. It is fixed to the jacket 24 in a thermally coupled state. Each battery cell 30 consists of a square-shaped lithium ion secondary battery. However, each battery cell 30 may be another battery or capacitor such as a nickel metal hydride battery or a nickel cadmium battery instead of the lithium ion secondary battery.

  Further, inside the power storage device, a current sensor 31 as a current measurement unit that measures a current flowing through the power storage device 8, a voltage sensor 32 as a voltage measurement unit that measures the voltage of each battery cell 30, and each battery cell 30. A temperature sensor 33 is attached as a temperature measuring unit for measuring the temperature of each. For the voltage and temperature having a plurality of sensors, the average value, maximum value, and minimum value are calculated from the measured values of the voltage and temperature of each battery cell 30. Then, the controller 11 calculates the amount of power stored in the power storage device 8 based on the current measured by the current sensor 31, the voltage measured by the voltage sensor 32, the temperature measured by the temperature sensor 33, and the like. The amount of electricity stored in the device 8 is managed. Further, the controller 11 calculates a charging rate (SOC) from, for example, the calculated amount of power stored in the power storage device 8.

  The water jacket 24 is formed of a thin plate-like metal member, and although not shown, the equipment cooling medium inlet into which the equipment cooling medium flows into the inside, and the equipment cooling medium that is formed inside and flows in from the equipment cooling medium inlet. And an equipment cooling medium outlet through which the equipment cooling medium circulated through the groove flows out to the outside. The equipment cooling medium circulating inside the water jacket 24 is connected to each battery via the heat conductive sheet 36. The cell 30 is deprived of heat.

  Moreover, since the water jacket 24 is a metal member as described above, there is a potential difference between adjacent battery cells 30. Therefore, when the battery cell 30 is brought into direct contact with the water jacket 24, a large short current flows. The heat conductive sheet 36 interposed between the battery cell 30 and the water jacket 24 has a function of avoiding such a short current. That is, the heat conductive sheet 36 insulates the battery cell 30 and the water jacket 24 and efficiently exchanges heat between the battery cell 30 and the water jacket 24. The heat conductive sheet 36 is made of an elastic body. As the elastic body, for example, a silicon resin sheet, a plastic sheet filled with a filler having excellent heat conductivity, mica, or the like is used, and the same function is used. Others may be used if they exist.

  FIG. 4 is a diagram showing the relationship between the charging rate (SOC) of the power storage device and the allowable output according to the present embodiment for each temperature (low temperature, medium temperature, high temperature) of the power storage device, and FIG. 5 is related to the present embodiment. It is a figure which shows the structure of a controller.

  As shown in FIG. 4, the allowable output of the power storage device 8 decreases at a low temperature. Therefore, in order to use the power storage device 8 without reducing the allowable output, it is necessary to warm the power storage device 8 to a predetermined temperature or higher. That is, it is necessary to keep the power storage device 8 in an appropriate temperature range by warming up the power storage device 8. In particular, when the hydraulic excavator is started in winter when the temperature of the outside air is low, it may be preferable to warm up the power storage device 8 in advance before starting work in order to increase the allowable output of the power storage device 8. Therefore, the controller 11 has a function as a control device that controls charging / discharging of the power storage device 8, and forcibly charges and discharges the power storage device 8 to generate heat with the internal resistance (DCR) of the power storage device 8. The power storage device 8 is warmed up.

  Specifically, as shown in FIG. 5, the controller 11 includes a charge / discharge state determination unit 11 a that determines the charge / discharge state of the power storage device 8, a voltage measured by the voltage sensor 32, and a charge / discharge state determination unit 11 a. Based on the state of charge / discharge of the determined power storage device 8 and a predetermined upper and lower limit value of the voltage of the power storage device 8, a calculation unit 11b that calculates a current for charging / discharging the power storage device 8 and the calculation unit 11b A current control unit 11c that controls a current that flows through the power storage device 8 during the warm-up operation of the power storage device 8 according to the calculated current is included. The predetermined upper and lower limit values of the voltage of the power storage device 8 are determined in advance as the voltage upper limit value Vmax and the voltage lower limit value Vmin of the battery cell 30 according to the battery cell specification or the hydraulic excavator system specification.

  In addition, the controller 11 determines the first warm-up operation determination unit 11d that determines whether or not to perform the warm-up operation of the power storage device 8 based on the temperature measured by the temperature sensor 33, and the operation output of the vehicle body. A second warm-up that determines whether or not the warm-up operation of the power storage device 8 is performed by comparing an output required for the power storage device 8 (hereinafter referred to as a vehicle body required output for convenience) and an allowable output of the power storage device 8. A machine operation determination unit 11e and a restriction unit 11f that restricts the operation of the vehicle body based on the allowable output of the power storage device 8 are included. Furthermore, the cab 3 includes a monitor 3a as a display device that displays information related to the operation of the vehicle body when the operation of the vehicle body is restricted by the restriction unit 11f.

  FIG. 6 is a diagram illustrating a vehicle body required output used for control of the controller according to the present embodiment, and FIG. 7 is a diagram illustrating another example of the vehicle body required output used for control of the controller according to the present embodiment.

  Here, the vehicle body required output is set to a predetermined output value P0 when the vehicle body operation output set by the engine rotation speed adjustment dial 3b is “small output” as shown in FIG. When the operation output of the vehicle body set by the dial 3b is “high output”, it is set to a predetermined output value P1 (> P0) larger than the output value P0 described above.

  The vehicle body required output may be set according to the output required to drive the assist power generation motor 2 with respect to the operation of the vehicle body. For example, as shown in FIG. 7, when the assist generator motor 2 is driven to start the engine 1, the required output of the vehicle body is “small output” P0, and the assist generator motor 2 is driven to operate the traveling body 100. P3 (> P0), which is a “medium output” when the vehicle body required output is set to P4 (> P0), which is a “large output”, when the assist generator motor 2 is driven to operate the front work machine 70. P3) may be set. In this case, the controller 11 determines the operation of the vehicle body from the start time of the hydraulic excavator and the operation position of the operation lever 4a in the cab 3.

  Next, the operation | movement operation | movement of the temperature control apparatus 20 which concerns on this embodiment is demonstrated with reference to FIG.

  The temperature adjustment of the power storage device 8 may be performed when the equipment cooling medium to which the heat of the power storage device 8 is transferred is cooled by the radiator 26, or may be warmed up by charging / discharging of the power storage device 8 as described later. The operation 20 changes in accordance with the temperature of the power storage device 8. When the temperature of the power storage device 8 measured by the temperature sensor 33 is higher than a predetermined temperature T1, the temperature adjustment device 20 drives the pump 23 of the cooling circuit 21 to thereby cool the equipment cooling medium discharged from the pump 23. Circulate through the jacket 24 and the radiator 26.

  At this time, the heat generated in the power storage device 8 is transferred to the equipment cooling medium circulating in the water jacket 24, so that the equipment cooling medium warmed in the water jacket 24 is supplied to the radiator 26 and cooled. In order to control the temperature of the power storage device 8, the flow rate of the equipment cooling medium discharged from the pump 23 or the air volume of the outside air blown by the fan 27 may be adjusted.

  Specifically, when the temperature of the power storage device 8 measured by the temperature sensor 33 is higher than the target temperature, the flow rate of the equipment cooling medium discharged from the pump 23 is increased, or the outside air blown by the fan 27 It is sufficient to increase the air volume. On the other hand, when the temperature of the power storage device 8 measured by the temperature sensor 33 is lower than the target temperature, the flow rate of the equipment cooling medium discharged from the pump 23 is decreased, or the air volume of the outside air blown by the fan 27 is reduced. Reduce it.

  Next, the warm-up operation of the power storage device 8 by the controller 11 according to the present embodiment will be described with reference to FIG. During the warm-up operation of the power storage device 8, the controller 11 operates the pump 23 of the temperature control device 20 in order to prevent the heat of the power storage device 8 from escaping to the equipment cooling medium by the water jacket 24. It has stopped. In addition, the current sensor 31 and the voltage sensor 33 measure the current and voltage of the power storage device 8 at predetermined time intervals, respectively.

  FIG. 8 is a flowchart for explaining the warm-up operation of the power storage device by the controller according to this embodiment, and FIG. 9 is a diagram for explaining the current limit value for charging and discharging the power storage device according to this embodiment. FIG. 10 is a flowchart illustrating another example of the warm-up operation of the power storage device by the controller according to the present embodiment.

  First, the first warm-up operation determination unit 11d of the controller 11 determines whether or not the temperature measured by the temperature sensor 33 is equal to or lower than a predetermined temperature T2 ((step (hereinafter referred to as S) 201). When the first warm-up operation determination unit 11d determines that the temperature measured by the temperature sensor 33 is higher than the predetermined temperature T2 (S201 / NO), the first warm-up operation determination unit 11d determines not to perform the warm-up operation of the power storage device 8. , The operation from S201 is repeated (S208).

  As described above, when the temperature of the power storage device 8 is high and a sufficient output can be obtained from the power storage device 8, it is not necessary to perform the warm-up operation of the power storage device 8. Discharging can be avoided. Thereby, since the frequency | count of use of the electrical storage apparatus 8 by warm-up operation can be decreased, it can suppress that an internal resistance (DCR) increases by deterioration of the electrical storage apparatus 8, and can perform the performance of the electrical storage apparatus 8 over a long term. Can be maintained.

  In S201, when the first warm-up operation determination unit 11d determines that the temperature measured by the temperature sensor 33 is equal to or lower than the predetermined temperature T2 (S201 / YES), the first warm-up operation determination unit 11d determines to perform the warm-up operation of the power storage device 8. Then, the second warm-up operation determination unit 11e of the controller 11 compares whether the vehicle body required output is larger than the allowable output of the power storage device 8 (S202). At this time, if the second warm-up operation determination unit 11e determines that the vehicle body required output is equal to or less than the allowable output of the power storage device 8 (S202 / NO), the second warm-up operation determination unit 11e determines that the warm-up operation of the power storage device 8 is not performed. The operation from S201 is repeated (S208). Thus, if the vehicle body required output is less than or equal to the allowable output of the power storage device 8, the allowable output can be taken out and the vehicle body can be operated sufficiently, so that excessive charging / discharging of the power storage device 8 can be avoided. The same effect as that obtained when the above-described first warm-up operation determination unit 11e determines not to perform the warm-up operation of the power storage device 8 can be obtained.

  On the other hand, when the second warm-up operation determination unit 11e determines in S202 that the vehicle body required output is larger than the allowable output of the power storage device 8 (S202 / YES), the second warm-up operation determination unit 11e determines that the power storage device 8 is to be warmed up. The charge / discharge state determination unit 11 a of the controller 11 determines the charge / discharge state of the power storage device 8. In the present embodiment, the charge / discharge state determination unit 11a determines whether the power storage device 8 is charged or discharged according to the charging rate (SOC) of the power storage device 8.

  For example, when the charging rate (SOC) of the power storage device 8 being charged reaches an upper limit value, the charge / discharge state determination unit 11a discharges the power storage device 8 so that the power storage device 8 switches from the charge state to the discharge state. When the charging rate (SOC) of the power storage device 8 being discharged reaches the lower limit value, the charge / discharge state determination unit 11a charges the power storage device 8 so that the power storage device 8 switches from the discharge state to the charge state. Judge that. In response to the determination result by the charge / discharge state determination unit 11a, the controller 11 charges and discharges the power storage device 8 so that the charging rate (SOC) of the power storage device 8 falls within the range between the upper limit value and the lower limit value (S203). ).

Then, the calculation unit 11b of the controller 11 obtains a predetermined value of the voltage measured by the voltage sensor 32, the charge / discharge state of the power storage device 8 determined by the charge / discharge state determination unit 11a in S203, and the voltage of the power storage device 8. Based on the lower limit values Vmax and Vmin, a current for charging / discharging the power storage device 8 is calculated. Here, the closed circuit voltage (CCV) which is the voltage between the terminals of one battery cell 30 in a state where a load is connected to the power storage device 8 is V1, and between one terminal in a state where the load is not connected to the power storage device 8 When the open circuit voltage (OCV), which is a voltage, is V2, the internal resistance (DCR) of the power storage device 8 is r, and the current flowing through the power storage device 8 is I, the following equation is established.

  Since the voltage of each battery cell 30 of the power storage device 8 needs to be set in a range between these voltage upper limit value Vmax and voltage lower limit value Vmin, if the current I during charging is a positive value, the closed circuit voltage (CCV ) It is necessary to set the current I to be smaller than the voltage upper limit value Vmax. On the other hand, if the current I during discharge is a negative value, the closed circuit voltage (CCV) V1 needs to be set to a current I that is greater than the voltage lower limit value Vmin.

  The open circuit voltage (OCV) V2 expressed by the above equation 1 varies depending on the temperature and the charging rate (SOC) of the battery cell 30, and the internal resistance (DCR) r also varies depending on the temperature and the charging rate (SOC) of the battery cell 30. . In particular, since the internal resistance (DCR) r becomes large at low temperatures, the current I that makes the closed circuit voltage (CCV) V1 smaller than the voltage upper limit value Vmax and smaller than the voltage lower limit value Vmin becomes smaller. That is, the current I is smaller at lower temperatures and larger at higher temperatures. Note that the current flowing through the power storage device 8 varies depending on the charge / discharge state of the power storage device 8.

  In the present embodiment, the calculation unit 11b charges the power storage device 8 by PI control from the difference between the closed circuit voltage (CCV) measured by the voltage sensor 32 and the voltage upper limit value Vmax every predetermined time when the power storage device 8 is charged. To derive the current. That is, the calculation unit 11b obtains a current such that the deviation between the closed circuit voltage (CCV) and the voltage upper limit value Vmax is zero.

  In addition, when the power storage device 8 is discharged, the arithmetic unit 11b discharges the power storage device 8 by PI control from the difference between the closed circuit voltage (CCV) measured by the voltage sensor 32 at a predetermined time and the voltage lower limit value Vmin. Is derived. That is, the calculation unit 11b obtains a current such that the deviation between the closed circuit voltage (CCV) and the voltage lower limit value Vmin is zero.

  Here, the calculation of the current by the calculation unit 11b may be performed using the above formula (1), but the formula (1) includes an open circuit voltage (OCV) and an internal resistance (DCR). Since the internal resistance (DCR) increases due to deterioration of the power storage device 8, it is not normally measured when mounted on a hydraulic excavator. Therefore, if Formula (1) is used for the calculation of the current for charging / discharging the power storage device 8, the internal resistance (DCR) when the power storage device 8 deteriorates must be estimated. If it is erroneously estimated that it is smaller than the actual value, the current I may flow too much through the power storage device 8, and the closed circuit voltage (CCV) may be larger than the voltage upper limit value Vmax or smaller than the voltage lower limit value Vmin. Therefore, the calculation of current using PI control by the calculation unit 11b according to the present embodiment described above is suitable.

  The calculation unit 11b of the controller 11 calculates the allowable output of the power storage device 8 by, for example, the product of the voltage of the power storage device 8 measured by the voltage sensor 32 and the calculated current. Thereby, since the measurement result of the voltage sensor 32 and the calculation result of the calculation unit 11b can be effectively used for the calculation of the allowable output of the power storage device 8, the allowable output of the power storage device 8 can be easily obtained. Therefore, the control operation of the warm-up operation of the power storage device 8 by the controller 11 can be executed smoothly. The calculation unit 11b does not calculate the allowable output of the power storage device 8 by the product of the voltage of the power storage device 8 measured by the voltage sensor 32 and the calculated current, for example, the temperature and the charging rate of the power storage device 8 (SOC) stores a relationship in which the allowable output of the power storage device 8 is set in advance as a map, and applies the temperature measured by the temperature sensor 33 and the charging rate (SOC) calculated by the controller 11 to this relationship. Thus, the allowable output of the power storage device 8 may be obtained.

  Next, the current control unit 11c of the controller 11 compares the current calculated by the calculation unit 11b in S204 with the current limit value Ilimit for charging / discharging the power storage device 8 to limit the current flowing to the power storage device 8. Set below the value Ilimit. Specifically, the limit value Ilimit is set to a predetermined current I1 when the temperature of the power storage device 8 is equal to or higher than a predetermined temperature T3, for example, as shown in FIG. It is determined whether the absolute value of the current calculated by the unit 11b is smaller than a current limit value I1 for charging / discharging the power storage device 8 (S205).

  At this time, if the current control unit 11c determines that the absolute value of the current calculated by the calculation unit 11b is equal to or greater than the current limit value I1 for charging / discharging the power storage device 8 (S205 / NO), for example, the power storage device 8 The warming-up operation is performed by setting the current to be supplied to the limit value I1 (S207), and the operation from S201 is repeated (S208). Therefore, even if the current calculated by the calculation unit 11b in S204 increases, the current flowing through the power storage device 8 during the warm-up operation is suppressed to the limit value I1, and therefore the current flowing through the power storage device 8 becomes excessive. Can be prevented. Thereby, the electrical storage apparatus 8 can be charged / discharged efficiently in a stable state.

  On the other hand, when current control unit 11c determines that the absolute value of the current calculated by calculation unit 11b is smaller than current limit value I1 for charging / discharging power storage device 8 (S205 / YES), calculation is performed by calculation unit 11b. A value obtained by multiplying the measured current by a coefficient α greater than 0 and smaller than 1 (0 <α <1) is set as the current I flowing through the power storage device 8 to perform warm-up operation (S206), and the operations from S201 are repeated. (S208).

  Here, when the coefficient α is large, it means that the current I flowing through the power storage device 8 is large, and the warm-up time of the power storage device 8 can be set short. growing. On the other hand, when the coefficient α is small, it means that the current I flowing through the power storage device 8 is small, and the burden on the power storage device 8 can be reduced, but the warm-up time of the power storage device 8 becomes long. Therefore, the balance between the advantages and disadvantages associated with the warm-up operation of the power storage device 8 can be freely set by appropriately adjusting the coefficient α according to the use environment and conditions of the hydraulic excavator. Thereby, it is possible to provide excellent convenience to an operator who uses the hydraulic excavator.

  In the present embodiment, at least one of the hydraulic pump 5, the hydraulic actuators 71a to 73a, and the valve device 12 constituting the hydraulic circuit is operated during the warm-up operation of the power storage device 8 in S206 or S207 to discharge the power storage device 8. I try to let them. Specifically, since the engine 1 and the hydraulic pump 5 are mechanically connected to the assist power generation motor 2, the engine 1 and the hydraulic pump 5 serve as an electrical load for the assist power generation motor 2.

  Therefore, for example, the hydraulic pump 5 is driven at an inefficient operating point, the opening degree of the valve device 12 is reduced according to the current calculated by the calculation unit 11b, or a load is applied to the hydraulic actuators 71a to 73a. As a result, the load on the hydraulic pump 5 increases, and the amount of power consumed by the assist power generation motor 2 for driving the hydraulic pump 5 can be increased. Therefore, the energy accumulated in the power storage device 8 can be efficiently released as discharge energy. Can do. Thereby, since the temperature of the electrical storage apparatus 8 can be raised early, the time required for the warm-up operation of the electrical storage apparatus 8 can be shortened, and the start time of work can be advanced.

  Furthermore, when the power storage device 8 is at a low temperature, the viscosity of the hydraulic oil circulating in the hydraulic circuit is high and energy loss increases. As described above, the hydraulic pump 5, the hydraulic actuators 71a to 73a, and the valve device 12 are operated to store power. By discharging the device 8, the hydraulic fluid flowing through the hydraulic circuit can be warmed up at the same time, so that sufficient energy loss of the hydraulic circuit can be achieved when starting work such as excavation using the front work machine 70. Can be reduced.

  On the other hand, the charging during the warm-up operation of the power storage device 8 in S206 or S207 is performed by causing the assist power generation motor 2 to generate power. The power storage device 8 is charged / discharged by the current I set by the current control unit 11c in S206 or the current Ilimit set by the current control unit 11c in S207. In this embodiment, the operation of the hydraulic excavator is performed. The power storage device 8 is charged and discharged by giving priority to the above.

  In the present embodiment, the current control unit 11c compares the current calculated by the calculation unit 11b with the current limit value Ilimit for charging / discharging the power storage device 8 in S205. Not limited to this, the current control unit 11c may set the current calculated by the calculation unit 11b as a current I that flows to the power storage device 8 as illustrated in FIG. 10 and perform the warm-up operation of the power storage device 8 (S205A). ). Therefore, in FIG. 10, it is not necessary to perform the operations of S205 and S207 shown in FIG.

  Further, in the present embodiment, when the power storage device 8 is warmed up as the temperature of the power storage device 8 measured by the temperature sensor 33, the first warm-up operation determination unit 11d in S201 warms up the power storage device 8. It is preferable to use the lowest temperature among the measured values of each battery cell 30 for determining whether or not the operation is performed. On the other hand, when the temperature control device 20 is operated to cool the power storage device 8, it is preferable to use the highest temperature among the measured values of each battery cell 30 for determining whether or not the cooling operation of the power storage device 8 is performed.

  Further, according to the present embodiment, when the calculation unit 11b derives a current for charging the power storage device 8 in S204 as the voltage of the power storage device 8 measured by the voltage sensor 33, It is preferable to use the minimum voltage among the measured values of each battery cell 30 when the calculation unit 11b derives a current for discharging the power storage device 8 using the maximum voltage. In this case, the voltage of all the battery cells 30 of the power storage device 8 can be controlled in the range between the voltage upper limit value Vmax and the voltage lower limit value Vmin in S206 or S207.

  FIG. 11 is a diagram illustrating a time transition of the current, voltage, and charging rate (SOC) of the power storage device when the power storage device according to the present embodiment is warmed up, and FIG. 12 is a diagram illustrating warm-up of the power storage device according to the present embodiment. It is a figure which shows the time transition of the temperature of an electrical storage apparatus when it drive | operates, and an allowable output.

  As shown in FIG. 11, when the warm-up operation of power storage device 8 is performed, the voltage and current of power storage device 8 change according to the change in the charging rate (SOC) of power storage device 8, and the voltage of power storage device 8 is It can be seen that the voltage is controlled in the range between the voltage upper limit value Vmax and the voltage lower limit value Vmin. Further, as shown in FIG. 12, the temperature of power storage device 8 rises due to the warm-up operation, and the allowable output of power storage device 8 increases accordingly, and the absolute value of the current of power storage device 8 as shown in FIG. You can see that it is getting bigger. As described above, in the present embodiment, by controlling the current flowing through the power storage device 8 by the current control unit 11c, charging / discharging of the power storage device 8 is efficiently performed within the upper and lower limit values Vmax and Vmin of the voltage of the power storage device 8. Since this can be repeated, the power storage device 8 can be quickly warmed up and the life of the power storage device 8 can be improved.

  Next, the operation of the limiting unit 11f of the controller 11 according to the present embodiment will be described with reference to FIGS.

  FIG. 13 is a diagram showing the relationship between the allowable output of the power storage device stored in the controller according to the present embodiment and the operation output of the vehicle body, and FIG. 14 is the allowable output of the power storage device stored in the controller according to the present embodiment and the vehicle body. It is a figure which shows the other example of a relationship with the operation | movement output of.

  As described above, the allowable output of the power storage device 8 increases due to the warm-up operation of the power storage device 8, but the limiting unit 11 f of the controller 11 determines that the vehicle body demand output is larger than the allowable output of the power storage device 8. By setting the operation output to be equal to or lower than the preset output with respect to the allowable output of the power storage device 8, the operation of the vehicle body is limited.

  Specifically, the controller 11 stores a relationship in which the vehicle body operation output is preset with respect to the allowable output of the power storage device 8, and this relationship is divided into, for example, two regions as shown in FIG. 13. When the allowable output of the power storage device 8 is not less than P0 and less than P1, the operation output of the vehicle body is set to “small output”, and when the allowable output of the power storage device 8 is not less than P1 and less than P2 (> P1) The output is set to “large output”. When “medium output” can be set as the operation output of the vehicle body, the above-described relationship is divided into three regions as shown in FIG. 14, for example, and the allowable output of the power storage device 8 is P0 or more and P3 (> When it is less than P0), the vehicle body operation output is set to “small output”, and when the allowable output of the power storage device 8 is P3 or more and less than P4 (> P3), the vehicle body operation output is set to “medium output”. When the allowable output of power storage device 8 is not less than P4 and less than P2 (> P4), the operation output of the vehicle body is set to “large output”. Further, the above relationship may be divided into four or more regions according to the operation output of the vehicle body.

  For example, as shown in FIG. 13, when the operator in the cab 3 selects the “high output” setting of the vehicle body operation output by the engine speed adjustment dial 3 b, the temperature of the power storage device 8 is low, When the allowable output of the device 8 is less than P1, the limiter 11f sets the operation output of the vehicle body to “small output” corresponding to the allowable output. As a result, the operation of the vehicle body is restricted by the restricting portion 11f, so that the engine 1 suddenly performs power running (drive) / regeneration (power generation) of the assist power generation motor 2 in order to obtain an allowable output necessary for operating the vehicle body. Since the excessive warm-up operation is not performed repeatedly, the fuel consumption of the engine 1 associated with such a warm-up operation can be suppressed. Thereby, energy efficiency can be improved. Further, even if the operation of the vehicle body is restricted, the operation of the vehicle body is not completely stopped, and the operator can move the vehicle body using the output of the power storage device 8, so that the warm-up operation of the power storage device 8 is performed. Even during the operation, the convenience of the operator who performs the work can be sufficiently ensured.

  When the operation of the vehicle body is restricted by the restriction unit 11f, the monitor 3a in the operator cab 3 sets the operation output of the vehicle body, for example, by the operator using the engine speed adjustment dial 3b as information on the operation of the vehicle body. When “high output” is selected, it is displayed that the power storage device 8 is at a low temperature and the operation output of the vehicle body is forcibly set to “small output”. Thus, the operator can easily grasp that the operation of the vehicle body is restricted due to the temperature of the power storage device 8 by checking the information displayed on the monitor 3a.

  Therefore, the operator can suspend the work and wait until the warm-up operation of the power storage device 8 is completed, and can prepare for the work by the hydraulic excavator. When the temperature of the power storage device 8 becomes high due to the warm-up operation and the allowable output of the power storage device 8 is equal to or higher than P1, the limiting unit 11f displays “high” as the operator selects the operation output of the vehicle body. Set to “Output”. As a result, the operator can smoothly perform work such as excavation by the front work machine 70.

  Note that the monitor 3a in the cab 3 is another example of the information on the operation of the vehicle body, when the temperature of the power storage device 8 is increased by the warm-up operation, and the allowable output of the power storage device 8 becomes P1 or more. It may be displayed whether or not the operation output of the vehicle body may be shifted from “small output” to “large output”, and a message that prompts the operator to confirm and select it may be displayed. Further, the monitor 3a includes “engine start possible”, “running body operable”, and “front work machine operable” according to the allowable output of the power storage device 8, as other examples of information relating to the operation of the vehicle body. The operable content of the vehicle body may be displayed, or the time required for the warm-up operation of the power storage device 8, that is, the waiting time of the operator may be displayed.

  According to the present embodiment configured as described above, the current control unit 11c of the controller 11 includes the voltage measured by the voltage sensor 32, the charge / discharge state of the power storage device 8 determined by the charge / discharge state determination unit 11a, and Considering a predetermined upper and lower limit value of the voltage of the power storage device 8, the current flowing through the power storage device 8 is controlled to an appropriate range for charging and discharging the power storage device 8, so that the power storage device 8 is in an overcharged state. Or an overdischarged state can be prevented, and the burden on the power storage device 8 accompanying an increase in the current flowing through the power storage device 8 can be reduced. Accordingly, the power storage device 8 can be quickly warmed up and the life of the power storage device 8 can be improved, so that the power storage device 8 can be used for a long time. Therefore, since the replacement frequency of the power storage device 8 can be reduced, labor required for maintenance work of the power storage device 8 can be reduced and the replacement cost of the power storage device 8 can be suppressed.

  In addition, this embodiment mentioned above was described in detail in order to demonstrate this invention easily, and is not necessarily limited to what is provided with all the demonstrated structures. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment.

  The hybrid construction machine according to the present embodiment has been described with respect to a hybrid hydraulic excavator. However, the present invention is not limited to this and may be a construction machine such as a hybrid wheel loader.

1 engine (motor)
2 Assist generator motor (electric motor)
3 cab 3a monitor (display device)
3b Engine speed adjustment dial (output setting section)
4 Operation device 4a Operation lever 5 Hydraulic pump 8 Power storage device 9 Inverter device 11 Controller 11a Charge / discharge state determination unit 11b Calculation unit 11c Current control unit 11d First warm-up operation determination unit 11e Second warm-up operation determination unit 11f Limit Unit 12 Valve device 20 Temperature control device 30 Battery cell 31 Current sensor 32 Voltage sensor (voltage measurement unit)
33 Temperature sensor (voltage measurement unit)
36 Heat conduction sheet 90 Hydraulic system

Claims (6)

Prime mover,
A motor generator for assisting the power of the prime mover and generating electricity;
A power storage device that transfers power to and from the motor generator;
A control device for controlling charging and discharging of the power storage device;
A voltage measuring unit that measures the voltage of the power storage device,
The controller is
A charge / discharge state determination unit for determining a charge / discharge state of the power storage device;
Based on the voltage measured by the voltage measurement unit, the state of charge / discharge of the power storage device determined by the charge / discharge state determination unit, and a predetermined upper and lower limit value of the voltage of the power storage device, charging / discharging of the power storage device is performed. A calculation unit for calculating a current for discharging;
A current control unit that controls a current flowing through the power storage device during a warm-up operation of the power storage device according to the current calculated by the calculation unit;
The computing unit is
At the time of charging the power storage device, a current is calculated such that a deviation between a voltage measured by the voltage measuring unit and a predetermined upper limit value of the voltage of the power storage device is zero,
At the time of discharging the power storage device, a current is calculated such that a deviation between a voltage measured by the voltage measuring unit and a predetermined lower limit value of the voltage of the power storage device is zero ,
The current controller is
A warm-up operation determination unit that determines whether or not to perform a warm-up operation of the power storage device by comparing an output required for the power storage device with respect to an operation output of a vehicle body and an allowable output of the power storage device; A hybrid construction machine , wherein a current flowing through the power storage device is controlled when it is determined by the warm-up operation determination unit that the power storage device is to be warmed up . The hybrid construction machine according to claim 1,
An allowable output of the power storage device is calculated by a product of a voltage of the power storage device measured by the voltage measurement unit and a current calculated by the calculation unit. . The hybrid construction machine according to claim 1,
The controller is
A hybrid construction machine , comprising: a limiting unit that limits the operation of the vehicle body based on an allowable output of the power storage device . The hybrid construction machine according to claim 3 ,
An output setting unit for setting the operation output of the vehicle body;
The restriction unit is
When the output required for the power storage device with respect to the output set by the output setting unit is larger than the allowable output of the power storage device, the operation output of the vehicle body is preset with respect to the allowable output of the power storage device. The hybrid construction machine is characterized in that the operation of the vehicle body is restricted by setting the output to be less than the output . The hybrid construction machine according to claim 4 ,
A hybrid construction machine, comprising: a display device that displays information on the operation of the vehicle body when the operation of the vehicle body is restricted by the restriction unit . The hybrid construction machine according to claim 1 ,
A hydraulic pump connected to the motor generator;
A hydraulic actuator driven by pressure oil discharged from the hydraulic pump;
A valve device for controlling the flow rate and direction of the pressure oil supplied to the hydraulic actuator,
The controller is
When it is determined by the warm-up operation determination unit that the power storage device is to be warmed up, at least one of the hydraulic pump, the hydraulic actuator, and the valve device is operated to discharge the power storage device. A hybrid construction machine characterized by the above.