Electric power machinery

Abstract

This makes it easier for operators of electric power machinery to know the status of low-voltage batteries. [Solution] An electric work machine comprising: a high-voltage battery that supplies power to the electric work machine; a low-voltage battery that is charged by the power supplied from the high-voltage battery; a starting device for starting the electric work machine; and a control device that, when the starting device is operated, supplies power from the high-voltage battery to make the electric work machine operational, wherein the control device detects the state of the low-voltage battery before starting to supply power from the high-voltage battery to the low-voltage battery when the starting device is operated.

Description

Technical Field

[0001] This disclosure relates to electric working machines.

Background Art

[0002] As an electric working machine, one equipped with a high-voltage battery and a low-voltage battery is known. Since the low-voltage battery is charged by the power supplied from the high-voltage battery, when determining whether it is deteriorated by measuring the voltage or the like, it is necessary to be in a state where power is not supplied from the high-voltage battery.

[0003] Patent Document 1 discloses a mechanism for detecting the state of a low-voltage battery when the electric working machine is in a non-operating state.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] What is disclosed in Patent Document 1 detects the state of the low-voltage battery when the electric working machine is in a non-operating state to prevent overcharging of the low-voltage battery. Therefore, the state of the low-voltage battery is detected when the operator operating the electric working machine is away from the electric working machine.

[0006] Therefore, there is a problem that it is difficult for the operator operating the electric working machine to know the state of the low-voltage battery.

[0007] Therefore, it is preferable to provide an electric working machine that allows the operator operating the electric working machine to easily know the state of the low-voltage battery.

Means for Solving the Problems

[0008] To achieve the above objectives, this disclosure is made Electric power machinery, A high-voltage battery that supplies power to the electric work machine, A low-voltage battery that is charged by power supplied from the aforementioned high-voltage battery, A starting device for starting the aforementioned electric work machine, The system includes a control device that, when the starting device is operated, supplies power from the high-voltage battery to make the electric work machine operational, When an operation is performed on the starting device, the control device detects the state of the low-voltage battery before starting to supply power from the high-voltage battery to the low-voltage battery. [Effects of the Invention]

[0009] According to this disclosure, operators of electric power machinery can easily know the status of the low-voltage battery. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view showing an excavator according to this embodiment. [Figure 2] This is a block diagram schematically showing an example of the configuration of the shovel according to this embodiment. [Figure 3] Figure 2 is a block diagram showing some examples of the configuration of an excavator controller. [Figure 4] This is a flowchart illustrating the method for detecting the battery status in this embodiment. [Figure 5] This figure shows an example of a battery status notification. [Figure 6] Figure 2 is a block diagram showing some examples of the configuration of an excavator controller. [Figure 7] This is a flowchart illustrating the method for detecting the battery status in this embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. Furthermore, the embodiments described below are illustrative and not limiting to the invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. In addition, identical or corresponding components in each drawing are denoted by the same or corresponding reference numerals, and their descriptions may be omitted.

[0012] First, as an example of an electric work machine, an overview of the excavator 200 according to this embodiment will be described. Note that the electric work machine is not limited to the excavator 200, but may also be a crane or a forklift, etc. In that case, although it does not have a separate lower traveling body 1 and upper rotating body 3 as the excavator 200 described later, it will have a configuration consisting of a main body that controls movement, etc., and an attachment that performs work, similar to the configuration of the excavator 200 which consists of a lower traveling body 1 and an upper rotating body 3. [Shovel Overview] As shown in Figure 1, the excavator 200 according to this embodiment comprises a lower traveling body 1, an upper rotating body 3 mounted on the lower traveling body 1 so as to be rotatable via a slewing mechanism 2, a boom 4, an arm 5 and a bucket 6 as attachments, and a cabin 10.

[0013] The lower traveling body 1 includes, for example, a pair of left and right crawlers, and each crawler is hydraulically driven by a travel hydraulic motor 1R, 1L (see Figure 2), allowing it to move under its own power. The lower traveling body 1 is not limited to those using crawlers as shown in the figure; it may also be a wheeled shovel type with tires.

[0014] The upper swing body 3 swings with respect to the lower traveling body 1 by being hydraulically driven by a swing hydraulic motor 2M (see FIG. 2) through a swing mechanism 2. All driven elements (for example, the swing hydraulic motor 2M) are hydraulically driven by hydraulic oil supplied from a main pump 14 (see FIG. 2). This corresponds to a configuration in which the power source (engine) of a so-called hydraulic excavator is replaced with a pump motor 12.

[0015] Alternatively, the upper swing body 3 may be electrically driven by a swing electric motor that is driven by electric power supplied from a battery module 19 through the swing mechanism 2 instead of the swing hydraulic motor 2M. In this case, for example, the excavator 200 is connected from the battery module 19 to the swing electric motor via an inverter. Then, the swing electric motor may perform a power running operation of swing-driving the upper swing body 3 and a regeneration operation of generating regenerative power to swing-brake the upper swing body 3 under the control of an excavator controller 30 and the inverter. Further, the swing electric motor may supply regenerative power to the battery module 19 or the pump motor 12 via the inverter.

[0016] The boom 4 is attached to the front center of the upper swing body 3 so as to be able to pitch. An arm 5 is attached to the tip of the boom 4 so as to be able to rotate vertically, and a bucket 6 is attached to the tip of the arm 5 so as to be able to rotate vertically. The boom 4, the arm 5, and the bucket 6 are each hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 as hydraulic actuators.

[0017] The bucket 6 is an example of an end attachment. Another end attachment may be attached to the tip of the arm 5 instead of the bucket 6 according to the work content or the like. The other end attachment may be, for example, a bucket of a different type from the bucket 6 such as a slope bucket or a dredging bucket. Further, the other end attachment may be, for example, an end attachment of a different type from the bucket such as a breaker, a stirrer, or a grapple.

[0018] The cabin 10 is mounted on the front left side of the upper rotating body 3, and its interior (room) is equipped with a cockpit where the operator sits, as well as control devices 26 (see Figure 2), which will be described later.

[0019] The shovel 200 operates its driven elements, such as the lower travel body 1 (left and right crawlers), upper slewing body 3, boom 4, arm 5, and bucket 6, in response to the operation of the operator seated in the cabin 10.

[0020] Furthermore, instead of being configured to be operable by an operator in the cabin 10, or in addition to being configured to be remotely operated from outside the shovel 200, it may also be configured to be remotely operated. When the shovel 200 is remotely operated, the cabin 10 may be unoccupied. The following explanation will proceed on the premise that operator operation includes at least one of operation of the operator's control device 26 in the cabin 10 and remote operation by an external operator.

[0021] The imaging device 40 captures images of the area around the shovel 200 and acquires the images. The imaging device 40 outputs the captured image data, which is the result of the imaging, to the shovel controller 30.

[0022] The imaging device 40 may be, for example, a monocular camera, a stereo camera, or a depth camera. The imaging device 40 may also acquire three-dimensional data (for example, point cloud data or surface data) representing the position and outline of objects around the shovel 200 within a predetermined imaging range (angle of view) based on the captured image data.

[0023] For example, four imaging devices 40 are provided on the upper rotating body 3, and each imaging device 40 captures images of the front, rear, left, and right sides of the upper rotating body 3. This allows the operator to check the left, right, and rear views of the upper rotating body 3 via the output device 50 (see Figure 2) or the remote control display device.

[0024] Remote operation includes, for example, a mode in which the shovel 200 is operated by operation inputs related to the actuator of the shovel 200 performed by a predetermined external device. In this case, the shovel 200 is equipped with communication equipment (not shown) capable of communicating with a predetermined external device, and may transmit image information (captured image) output by the imaging device 40 to the external device. The external device may then display the received image information (captured image) on a display device provided in its own device (hereinafter referred to as the "remote operation display device"). Furthermore, various information images (information screens) displayed on the output device 50 (display device) inside the cabin 10 of the shovel 200 may also be displayed on the remote operation display device of the external device. This allows the operator of the external device to remotely operate the shovel 200 while checking the displayed content, such as captured images and information screens showing the surroundings of the shovel 200, displayed on the remote operation display device. The shovel 200 may then operate a hydraulic actuator in response to a remote control signal, which is received from an external device via a communication device and represents the content of the remote control, thereby driving the driven elements such as the lower traveling body 1 (left and right crawlers), the upper slewing body 3, the boom 4, the arm 5, and the bucket 6.

[0025] Furthermore, remote operation may include, for example, a mode in which the shovel 200 is operated by external voice input or gesture input from people (e.g., workers) in the vicinity of the shovel 200. Specifically, the shovel 200 recognizes voices spoken by surrounding workers or gestures made by workers through a voice input device (e.g., microphone) or gesture input device (e.g., imaging device 40) mounted on the shovel 200 (itself). The shovel 200 may then operate actuators according to the content of the recognized voices or gestures to drive driven elements such as the lower traveling body 1 (left and right crawlers), the upper slewing body 3, the boom 4, the arm 5, and the bucket 6.

[0026] Furthermore, the shovel 200 may operate its actuators automatically, regardless of the operator's actions. This enables the shovel 200 to automatically operate at least some of its driven elements, such as the lower crawler body 1, upper slewing body 3, boom 4, arm 5, and bucket 6 (a so-called "automatic driving function" or "machine control function").

[0027] The automatic driving function may include a function that automatically operates driven elements (actuators) other than the target driven element (hydraulic actuator) in response to the operator's operation device 26 or remote operation (a so-called "semi-automatic driving function"). The automatic driving function may also include a function that automatically operates at least some of the multiple driven elements (actuators) on the premise that there is no operator operation device 26 or remote operation (a so-called "fully automatic driving function"). In the case of the shovel 200, if the fully automatic driving function is enabled, the interior of the cabin 10 may be unoccupied. Furthermore, the semi-automatic driving function and fully automatic driving function may include a mode in which the operation content of the driven elements (actuators) subject to automatic driving is automatically determined according to predetermined rules. Furthermore, the semi-automatic driving function and fully automatic driving function may also include a mode in which the shovel 200 autonomously makes various judgments, and the operation content of the driven elements (actuators) subject to automatic driving is autonomously determined according to the results of those judgments (a so-called "autonomous driving function").

[0028] [Shovel configuration] Next, with reference to Figure 1 and Figure 2, the configuration of the shovel 200 according to this embodiment will be described.

[0029] Figure 2 is a schematic block diagram showing an example of the configuration of the shovel 200 according to this embodiment.

[0030] In Figure 2, mechanical power lines are shown as double lines, hydraulic lines as thick solid lines, pilot lines as dashed lines, and electric drive / control lines as thin solid lines.

[0031] <Hydraulic drive system> The hydraulic drive system of the excavator 200 according to this embodiment includes hydraulic travel motors 1R and 1L, a swing hydraulic motor 2M, and hydraulic actuators such as a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, which hydraulically drive each of the driven elements such as the lower traveling body 1, boom 4, arm 5, and bucket 6. The hydraulic drive system of the excavator 200 according to this embodiment also includes a pump motor 12, a main pump 14, and a control valve 17.

[0032] The pump motor 12 (an example of a motor) is the power source for the hydraulic drive system. The pump motor 12 is, for example, an IPM (Interior Permanent Magnet) motor. The pump motor 12 is connected to a high-voltage power supply including a battery module 19 via an inverter 18. The pump motor 12 is powered by three-phase AC power supplied from the battery module 19 via the inverter 18 and drives the main pump 14 and the pilot pump 15. The drive control of the pump motor 12 may be performed by the inverter 18 under the control of the shovel controller 30, which will be described later.

[0033] The main pump 14 draws hydraulic fluid from the hydraulic fluid tank T and discharges it into the high-pressure hydraulic line 16, thereby supplying hydraulic fluid to the control valve 17 through the high-pressure hydraulic line 16. The main pump 14 is driven by a pump motor 12. The main pump 14 is, for example, a variable displacement hydraulic pump, and under the control of the shovel controller 30 (described later), a regulator (not shown) controls the angle (tilt angle) of the swash plate. This allows the main pump 14 to adjust the piston stroke length and thus adjust the discharge flow rate (discharge pressure).

[0034] The main pump 14 may be driven by power from another power source in addition to the electric motor 12 for the pump. For example, the energy of the hydraulic fluid discharged from the boom cylinder 7 and arm cylinder 8 to the hydraulic fluid tank due to the weight of the boom 4 and arm 5 when the boom 4 is lowered or the arm 5 is closed may be regenerated to drive the main pump 14. Specifically, the energy of the hydraulic fluid discharged from the boom cylinder 7 and arm cylinder 8 to the hydraulic fluid tank due to the weight of the boom 4 and arm 5 when the boom 4 is lowered or the arm 5 is closed may be used to drive a hydraulic motor arranged coaxially with the rotation axis of the main pump 14. Alternatively, the energy of the hydraulic fluid discharged from the boom cylinder 7 and arm cylinder 8 to the hydraulic fluid tank due to the weight of the boom 4 and arm 5 when the boom 4 is lowered or the arm 5 is closed may be regenerated to power a generator. Specifically, when the boom 4 is lowered or the arm 5 is closed, the energy of the hydraulic fluid discharged from the boom cylinder 7 and arm cylinder 8 into the hydraulic fluid tank due to the weight of the boom 4 and arm 5 can be used to drive a hydraulic motor arranged coaxially with the generator, thereby causing the generator to produce electricity. In this case, the power generated by the generator may be supplied to the pump motor 12 or used to charge the battery module 19.

[0035] The control valve 17 is a hydraulic control device that controls the hydraulic drive system in response to operator commands or automatic driving functions. As described above, the control valve 17 is connected to the main pump 14 via the high-pressure hydraulic line 16 and is configured to selectively supply hydraulic fluid from the main pump 14 to the hydraulic actuators (travel hydraulic motors 1R, 1L, swing hydraulic motor 2M, boom cylinder 7, arm cylinder 8, and bucket cylinder 9). For example, the control valve 17 is a valve unit that includes multiple control valves (directional control valves) that control the flow rate and direction of the hydraulic fluid supplied from the main pump 14 to each of the hydraulic actuators. The hydraulic fluid supplied from the main pump 14 and that has passed through the control valve 17 and hydraulic actuators is discharged from the control valve 17 to the hydraulic fluid tank T.

[0036] <Electric drive system> The electric drive system of the shovel 200 according to this embodiment includes a pump motor 12, a sensor 12s, and an inverter 18. Furthermore, the electric drive system of the shovel 200 according to this embodiment includes a high-voltage power supply configured by a battery module 19, etc. Additionally, the electric drive system of the shovel 200 according to this embodiment includes a key cylinder 60.

[0037] Sensor 12s includes a current sensor 12s1, a voltage sensor 12s2, and a rotational state sensor 12s3.

[0038] The current sensor 12s1 detects the current of each of the three phases (U phase, V phase, and W phase) of the pump motor 12. The current sensor 12s1 is installed, for example, in the power path between the pump motor 12 and the inverter 18. The detection signals corresponding to each of the three phases of the pump motor 12 detected by the current sensor 12s1 are directly received by the inverter 18 via a communication line. Alternatively, these detection signals may be received by the shovel controller 30 via a communication line and input to the inverter 18 via the shovel controller 30.

[0039] The voltage sensor 12s2 detects the applied voltage to each of the three phases of the pump motor 12. The voltage sensor 12s2 is installed, for example, in the power path between the pump motor 12 and the inverter 18. The detection signals corresponding to the applied voltages of each of the three phases of the pump motor 12 detected by the voltage sensor 12s2 are directly input to the inverter 18 via a communication line. Alternatively, these detection signals may be input to the shovel controller 30 via a communication line and then input to the inverter 18 via the shovel controller 30.

[0040] The rotational state sensor 12s3 detects the rotational state of the pump motor 12 (e.g., rotational position (rotation angle), rotational speed, etc.). The rotational state sensor 12s3 is, for example, a rotary encoder or a resolver.

[0041] The inverter 18 drives the pump motor 12 under the control of the shovel controller 30. The inverter 18 includes, for example, a conversion circuit that converts DC power to three-phase AC power and three-phase AC power to DC power, a drive circuit that switches and drives the conversion circuit, and a control circuit that outputs a control signal (for example, a PWM (Pulse Width Modulation) signal) that defines the operation of the drive circuit.

[0042] The control circuit of the inverter 18 controls the drive of the pump motor 12 while understanding its operating state. For example, the control circuit of the inverter 18 understands the operating state of the pump motor 12 based on the detection signal of the rotation state sensor 12s3. Alternatively, the control circuit of the inverter 18 may understand the operating state of the pump motor 12 by sequentially estimating the rotation angle of the rotation shaft of the pump motor 12 based on the detection signal of the current sensor 12s1 and the detection signal of the voltage sensor 12s2 (or the voltage command value generated during the control process).

[0043] Furthermore, at least one of the drive circuit and control circuit of the inverter 18 may be provided outside the inverter 18.

[0044] The battery module 19 is configured to supply charged power to the electronic components within the shovel 200. The specific configuration will be described later.

[0045] The key cylinder 60 is an example of a starting device in the present invention. The key cylinder 60 is operated when starting the shovel 200. For example, it is installed in the cabin 10, and when the operator of the shovel 200 inserts and turns the key, it outputs a starting signal to the shovel controller 30. A smart key may also be used as the starting device for starting the shovel 200. If a smart key is used as the starting device, the operator of the shovel 200 presses the switch (button) on the smart key, which outputs a starting signal to the shovel controller 30.

[0046] <Operation system> The operating system of the shovel 200 according to this embodiment includes a pilot pump 15, an operating device 26, and a pressure control valve 31.

[0047] The pilot pump 15 supplies pilot pressure to various hydraulic devices (e.g., pressure control valve 31) mounted on the shovel 200 via the pilot line 25. This allows the pressure control valve 31 to supply pilot pressure to the control valve 17 according to the operation of the operating device 26 (e.g., operating amount and direction) under the control of the shovel controller 30. Therefore, the shovel controller 30 and the pressure control valve 31 can realize the operation of the driven element (hydraulic actuator) according to the operation of the operating device 26 by the operator. Furthermore, the pressure control valve 31 can supply pilot pressure to the control valve 17 according to the remote operation content specified by the remote operation signal under the control of the shovel controller 30. The pilot pump 15 is, for example, a fixed-displacement hydraulic pump and is driven by the pump motor 12 as described above.

[0048] The control device 26 is located within reach of the operator in the cockpit of the cabin 10 and is used by the operator to operate each of the driven elements (i.e., the left and right crawlers of the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6, etc.). In other words, the control device 26 is used by the operator to operate the hydraulic actuators (e.g., travel hydraulic motors 1R, 1L, slewing hydraulic motor 2M, boom cylinder 7, arm cylinder 8, and bucket cylinder 9, etc.) or electric actuators that drive each of the driven elements. The control device 26 is, for example, electrically operated and outputs an electrical signal (hereinafter referred to as "operation signal") corresponding to the operator's operation. The operation signal output from the control device 26 is taken up by the shovel controller 30 via the signal line 28. As a result, the shovel controller 30 controls the pressure control valve 31 and controls the operation of the driven elements (actuators) of the shovel 200 in accordance with the operator's operation and operation commands corresponding to the automatic driving function.

[0049] The operating device 26 includes, for example, levers 26A to 26C. Lever 26A may be configured to accept operations on the arm 5 (arm cylinder 8) and the upper slewing body 3 (slewing motion) in response to forward / backward and left / right movements, respectively. Lever 26B may be configured to accept operations on the boom 4 (boom cylinder 7) and the bucket 6 (bucket cylinder 9) in response to forward / backward and left / right movements, respectively. Lever 26C may be configured to accept operations on the lower traveling body 1 (crawler), for example.

[0050] Furthermore, if the control valve 17 is composed of an electromagnetic pilot-operated control valve (directional control valve), the operating signal from the electric operating device 26 may be directly input to the control valve 17, and each hydraulic control valve may perform an operation according to the operation of the operating device 26. Alternatively, the operating device 26 may be a hydraulic pilot type that outputs a pilot pressure according to the operation. In this case, the pilot pressure according to the operation is supplied to the control valve 17.

[0051] The pressure control valve 31 outputs a predetermined pilot pressure using hydraulic fluid supplied from the pilot pump 15 through the pilot line 25 under the control of the shovel controller 30. The pilot line on the secondary side of the pressure control valve 31 is connected to the control valve 17, and the pilot pressure output from the pressure control valve 31 is supplied to the control valve 17.

[0052] <Power system> The power supply system of Shovel 200 is a group of components for supplying power to various electrical devices. Shovel 200 also includes a vehicle inlet 101 for normal charging and a vehicle inlet 102 for rapid charging as a configuration for charging the battery module 19.

[0053] The vehicle inlet 101 for normal charging is configured to be connectable to a charging connector (an example of a charging component) provided at the tip of a predetermined cable (hereinafter referred to as the "charging cable") of an external power supply.

[0054] The AC-DC converter 103 for charging converts AC power supplied from an external power source via the vehicle inlet 101 for normal charging into DC power that can be used to charge the battery 192, and supplies it to the battery module 19.

[0055] The rapid charging vehicle inlet 102 is configured to be connectable to a charging connector (an example of a charging component) provided at the end of a charging cable of an external power source (e.g., a charging station). The rapid charging vehicle inlet 102 is, for example, an inlet for performing rapid charging based on CHAdeMO®. In this embodiment, by using such a DC charging method, DC power can be supplied to the battery module 19 without going through an AC-DC converter.

[0056] This embodiment describes an example in which a charging component is directly connected to a vehicle inlet 101 for normal charging (an example of a charging port) and a vehicle inlet 102 for rapid charging (an example of a charging port) using a charging connector provided at the tip of a charging cable. However, this embodiment is not limited to the method of directly connecting to the vehicle inlet 101 for normal charging or the vehicle inlet 102 for rapid charging using a charging connector. For example, a charging component using a wireless power supply system may be connected to the charging port and charged from an external power source.

[0057] The battery module 19 of the excavator 200 according to this embodiment supplies power to each component within the excavator 200. The battery module 19 includes a battery 192 and a battery controller 191.

[0058] Battery 192 is an example of a high-voltage battery in the present invention. Battery 192 supplies power to various components within the shovel 200. For example, battery 192 supplies charged (stored) power to the pump motor 12. In other words, the power supplied by battery 192 is used to drive or turn the shovel 200 and to operate attachments. Battery 192 also charges the generated power (regenerative power) of the pump motor 12.

[0059] Battery 192 is charged (stored) by being connected to an external power source via a charging cable.

[0060] Battery 192 is, for example, a lithium-ion battery and has a relatively high output voltage (e.g., several hundred volts).

[0061] The battery controller 191 controls the internal configuration of the battery module 19. For example, the battery controller 191 monitors the temperature status of the battery 192 from the output of a temperature sensor (not shown) and calculates the State of Charge (SOC) of the battery 192. The battery controller 191 then outputs the temperature sensor detection result and the SOC to the shovel controller 30. This allows the shovel controller 30 to display the temperature of the battery 192 and the SOC of the battery 192 on the output device 50 (display device) inside the cabin 10.

[0062] The battery controller 191 according to this embodiment determines whether or not charging is possible depending on whether or not a charging connector is connected to the vehicle inlet 101 for normal charging or the vehicle inlet 102 for rapid charging. However, this embodiment is not limited to determining whether or not power can be supplied based on whether or not a charging connector is connected. For example, when wireless power supply is performed, other methods may be used, such as determining whether or not power can be supplied by mutual communication with charging equipment provided with an external power source.

[0063] The battery controller 191 then communicates with the charging equipment that has an external power source (e.g., a charging station) when it determines that it is connected to an external power source via a charging cable and charging connector (in other words, when it determines that it is in a state where power can be supplied). The battery controller 191 then communicates with the charging equipment and, if the charging equipment authorizes the supply of power, it starts supplying power from the external power source.

[0064] Furthermore, a power converter may be provided between the battery module 19 and the pump motor 12 to boost the output voltage of the battery module 19 and apply it to the pump motor 12. Also, as described above, when part or all of the driven part is electrically driven, the power from the battery module 19 is supplied to an electric actuator that electrically drives the driven part, either in place of or in addition to the pump motor 12.

[0065] The shovel 200 according to this embodiment includes a DC-DC converter 44 and a battery 46.

[0066] The DC-DC converter 44 is an example of a step-down converter in the present invention and is activated by control of the shovel controller 30 via the battery module 19. The DC-DC converter 44 is installed, for example, on the upper rotating body 3 and steps down the very high voltage DC power output from the battery module 19 to a predetermined voltage (for example, about 24 volts) and outputs it. The output power of the DC-DC converter 44 is supplied to the battery 46, where it is charged (stored) or supplied to electrical equipment (hereinafter referred to as "low-voltage equipment") that is powered by the battery 46. Low-voltage equipment includes, for example, the shovel controller 30. Low-voltage equipment also includes, for example, the air conditioning controller 81 and air conditioning unit 80 described later.

[0067] For example, as shown in Figure 2, the shovel 200 is equipped with one DC-DC converter 44.

[0068] The DC-DC converter 44 may be replaced with an alternator. In this case, the alternator may be installed on the upper rotating body 3 and generate electricity using the power of the pump motor 12. The power generated by the alternator is supplied to the battery 46, as in the case of the DC-DC converter 44, and is used to charge (store) the battery 46 or to supply low-voltage equipment such as the shovel controller 30.

[0069] Battery 46 is an example of a low-voltage battery in the present invention, and is, for example, a lead-acid battery. Battery 46 functions as a power source for low-voltage equipment, including the shovel controller 30, until the DC-DC converter 44 is started up and power supplied from the battery module 19 is supplied to the low-voltage equipment. After the DC-DC converter 44 is started up, battery 46 is charged by the power output from the battery module 19 and supplied via the DC-DC converter 44.

[0070] <Air conditioning system> The shovel 200 of this embodiment has an air conditioning system that includes an air conditioning unit 80 and an air conditioning controller 81 as low-voltage equipment.

[0071] Electrical equipment to which the power stepped down by the DC-DC converter 44 is supplied includes, for example, air conditioning equipment. Air conditioning equipment includes, for example, an air conditioning unit 80 and an air conditioning controller 81.

[0072] The air conditioning system 80 adjusts the temperature, humidity, etc., inside the cabin 10. The air conditioning system 80 may be a heat pump type, for example, which includes a heat pump cycle for both cooling and heating. Alternatively, the air conditioning system 80 may include, for example, a refrigeration cycle for cooling and a heater for heating. The heater for heating may be, for example, a PTC (Positive Temperature Coefficient) or a combustion heater. The air conditioning system 80 may also include a compressor that compresses the refrigerant flowing through the heat pump cycle or refrigeration cycle. The compressor may be driven by the power of the electric motor 12 for the pump.

[0073] The air conditioning controller 81 controls the air conditioning unit 80 according to requests from the shovel controller 30.

[0074] For example, when the air conditioning controller 81 receives an operation request for the compressor and air conditioning system 80 from the shovel controller 30, it controls the operation of the compressor and air conditioning system 80 according to the request. This allows the temperature or humidity of the air inside the cabin 10 to be adjusted.

[0075] Furthermore, the air conditioning controller 81 transmits information to the shovel controller 30 indicating the current status of the air conditioning unit 80. For example, the air conditioning controller 81 transmits information such as the target temperature of the air conditioning unit 80, the currently set airflow rate, and the amount of electricity currently being used by the air conditioning unit 80.

[0076] The air conditioning system in this embodiment is merely an example and is not limited to the configuration described above. Other electronic components may be included to adjust temperature and humidity.

[0077] <Control System> The control system for the shovel 200 according to this embodiment includes a shovel controller 30, an output device 50, an input device 52, and an imaging device 40.

[0078] The output device 50 is an example of a notification device in the present invention. The output device 50 is installed inside the cabin 10 and outputs various information to the operator under the control of the shovel controller 30. The output device 50 includes, for example, a display device that outputs (notifies) information to the operator in a visual manner. The display device may be installed in a location easily visible to the operator inside the cabin 10 and may display various information images under the control of the shovel controller 30. The display device may be, for example, a liquid crystal display or an organic EL (electroluminescence) display. The output device 50 also includes, for example, a sound output device that outputs information to the operator in an auditory manner. The sound output device may be, for example, a buzzer or a speaker.

[0079] Furthermore, the output device 50 (an example of a display device) may be detachably installed inside the cabin 10. The output device 50 may be configured to include a display device capable of outputting information to the operator, and may be, for example, a tablet terminal or a mobile communication terminal.

[0080] The input device 52 is located inside the cabin 10 and receives various inputs from the operator. The input device 52 may include, for example, an operation input device that receives operation inputs from the operator. The operation input device includes, for example, buttons, toggles, levers, touch panels, touch pads, etc. The input device 52 may also include, for example, an audio input device that receives voice inputs from the operator and a gesture input device that receives gesture inputs from the operator. The audio input device includes, for example, a microphone that acquires the voice of the operator inside the cabin 10. The gesture input device includes, for example, an indoor camera capable of capturing images of the operator's gestures inside the cabin 10. Signals corresponding to the operator inputs received by the input device 52 are taken up by the shovel controller 30.

[0081] The shovel controller 30 is an example of a control device in the present invention. The functions of the shovel controller 30 may be realized by any hardware, or any combination of hardware and software. For example, the shovel controller 30 may be centered around a computer that includes a processor such as a CPU (Central Processing Unit), a memory device (main memory) such as RAM (Random Access Memory), a non-volatile auxiliary storage device such as ROM (Read Only Memory), and an interface device for input / output with the outside.

[0082] The shovel controller 30 controls the drive of the shovel 200. For example, the shovel controller 30 outputs a control command to the pressure control valve 31 in response to an operation signal input from the operating device 26, and the pressure control valve 31 outputs a pilot pressure corresponding to the operation of the operating device 26. In this way, the shovel controller 30 can realize the operation of the driven elements (hydraulic actuators) of the shovel 200 that correspond to the operation of the electric operating device 26.

[0083] Furthermore, if the shovel 200 is remotely controlled, the shovel controller 30 may, for example, perform control related to the remote operation. Specifically, the shovel controller 30 may output a control command to the pressure control valve 31, causing the pressure control valve 31 to output a pilot pressure corresponding to the remote operation. This allows the shovel controller 30 to realize the operation of the shovel 200 (driven element) corresponding to the remote operation.

[0084] Furthermore, the shovel controller 30 may also perform control related to the automatic driving function, for example. Specifically, the shovel controller 30 may output a control command to the pressure control valve 31 and apply a pilot pressure corresponding to the operation command for the automatic driving function from the pressure control valve 31 to the control valve 17. In this way, the shovel controller 30 can realize the operation of the driven elements (hydraulic actuators) of the shovel 200 that correspond to the automatic driving function.

[0085] The shovel controller 30 may comprehensively control the operation of the entire shovel 200 (various devices mounted on the shovel 200).

[0086] The shovel controller 30 controls the electric drive system based on various input information (for example, control commands including operation signals from the operating device 26). The shovel controller 30 may also control the display on the output device 50 based on the image captured from the imaging device 40.

[0087] <Excavator Controller Function Blocks> The functional blocks within the shovel controller 30 will now be described. Each functional block within the shovel controller 30 is conceptual and does not necessarily need to be physically configured as shown in the diagram. All or part of each functional block can be configured by distributing and integrating them functionally or physically in any unit. Each processing function performed in each functional block is realized, all or any part thereof, by a program executed on the CPU. Alternatively, each functional block may be realized as hardware using wired logic. The program executed in the shovel controller 30 according to this embodiment is not limited to being stored in a non-volatile auxiliary storage device, but may also be stored in a distributable storage medium or transmitted and received via a communication line NW.

[0088] Figure 3 is a block diagram showing some configuration examples of the shovel controller 30 shown in Figure 2.

[0089] As shown in Figure 3, the shovel controller 30 in this embodiment includes a start signal receiving unit 301, a voltage measuring unit 302, a power supply instruction unit 303, a motor drive instruction unit 304, and a notification control unit 305.

[0090] The start signal receiving unit 301 receives a start signal output from the key cylinder 60 when the operator of the shovel 200 turns the key inserted into the key cylinder 60.

[0091] When the activation signal output from the key cylinder 60 is received by the activation signal receiving unit 301, the voltage measuring unit 302 detects the state of the battery 46 by measuring the voltage of the battery 46.

[0092] When the power supply instruction unit 303 receives a start signal output from the key cylinder 60 at the start signal receiving unit 301, it instructs the battery module 19 to supply power to the inverter 18 by connecting a high-voltage power supply to the inverter 18. Furthermore, when the power supply instruction unit 303 receives a start signal output from the key cylinder 60 at the start signal receiving unit 301, it instructs the battery module 19 to start the DC-DC converter 44.

[0093] Here, when the shovel controller 30 receives a start signal output from the key cylinder 60 at the start signal receiving unit 301, it first measures the voltage of the battery 46 at the voltage measuring unit 302, and then instructs the battery module 19 to start the DC-DC converter 44 at the power supply instruction unit 303. In other words, when an operation is performed on the key cylinder 60, the shovel controller 30 measures the voltage of the battery 46 before starting to supply power from the battery 192 to the battery 46 by starting the DC-DC converter 44.

[0094] When the motor drive instruction unit 304 receives a completion signal from the battery module 19 indicating that the high-voltage power supply has been connected to the inverter 18, it instructs the inverter 18 to drive the pump motor 12.

[0095] The notification control unit 305 determines whether the battery 46 is degraded based on the state of the battery 46 detected by the voltage measurement unit 302, and displays information corresponding to the determination result on the output device 50 via the output device 50.

[0096] [Battery status detection method] Figure 4 is a flowchart illustrating the method for detecting the state of the battery 46 in this embodiment.

[0097] When the key cylinder 60 is operated to start the shovel 200 and make it operational (YES in step ST11), a start signal is output from the key cylinder 60. An operational state means that the shovel 200 is able to move or rotate, and that attachments can be operated.

[0098] The ignition signal output from the key cylinder 60 is received by the ignition signal receiving unit 301 of the shovel controller 30, which first activates the shovel controller 30 (step ST12).

[0099] When the shovel controller 30 is started, the shovel controller 30 first detects the state of the battery 46 by measuring the voltage of the battery 46 in the voltage measurement unit 302 (step ST13).

[0100] After the shovel controller 30 measures the voltage of the battery 46 with the voltage measurement unit 302, the power supply instruction unit 303 instructs the battery module 19 to start the DC-DC converter 44. Furthermore, after the shovel controller 30 measures the voltage of the battery 46 with the voltage measurement unit 302, the power supply instruction unit 303 instructs the battery module 19 to supply power to the inverter 18 by connecting a high-voltage power supply to the inverter 18.

[0101] Then, the DC-DC converter 44 starts up (step ST14), and power is supplied from the battery 192 to the inverter 18. As a result, the power supplied from the battery 192 is stepped down by the DC-DC converter 44 and supplied to the air conditioning controller 81 and the air conditioning unit 80, etc., and the power supplied from the battery 192 is also supplied to the pump motor 12 via the inverter 18, making the shovel 200 operational.

[0102] Furthermore, when the DC-DC converter 44 is activated, the power supplied from the battery 192 is stepped down by the DC-DC converter 44 and supplied to the battery 46, which is then charged.

[0103] Thus, when the key cylinder 60 is operated, the shovel controller 30 detects the state of the battery 46 by measuring the voltage of the battery 46 before starting to supply power from the battery 192 to the battery 46 by activating the DC-DC converter 44. This is because, when the DC-DC converter 44 is activated, the DC-DC converter 44 supplies power to the battery 46 at a voltage higher than the current voltage of the battery 46, making it impossible to accurately measure the current voltage of the battery 46. Note that there is a small time lag between the activation of the shovel controller 30 when the key cylinder 60 is operated and the activation of the DC-DC converter 44, and this time lag is used to measure the voltage of the battery 46. In this case, a certain time lag may be intentionally created between the activation of the shovel controller 30 when the key cylinder 60 is operated and the activation of the DC-DC converter 44.

[0104] Furthermore, if the air conditioning controller 81 and air conditioning unit 80 are to be operated using only the power supplied by the battery 46 while the DC-DC converter 44 is not running, the load on the battery 46 will increase, and the operation of the air conditioning controller 81 and air conditioning unit 80 will become unstable. Therefore, the air conditioning controller 81 and air conditioning unit 80 are to be operated only after the DC-DC converter 44 has been started.

[0105] Next, the shovel controller 30 determines whether the voltage measured in step ST13 by the notification control unit 305 is below a degradation threshold (step ST15). The degradation threshold is set to determine whether the battery 46 is degraded and is stored in the notification control unit 305. For example, the degradation threshold may be 80% of the normal voltage of the battery 46. In that case, if the normal voltage of the battery 46 is 24V, the degradation threshold will be 19.2V. In addition to the voltage of the battery 46, the internal resistance value may also be used to determine whether the battery 46 is degraded. The internal resistance value of the battery 46 increases as the battery 46 degrades. Therefore, if the voltage of the battery 46 is below the degradation threshold and the internal resistance value of the battery 46 is above a predetermined value, it may be determined that the battery 46 is degraded.

[0106] If the notification control unit 305 determines that the voltage measured in step ST13 is below the degradation threshold (YES in step ST15), the notification control unit 305 notifies the output device 50 that it recommends replacing the battery 46 (step ST16).

[0107] Figure 5 shows an example of the main screen (screen SC1A) displayed on the image display unit 41M of the output device 50.

[0108] Screen SC1A includes a time display unit 411, an operation mode display unit 412, a driving mode display unit 413, an attachment display unit 414, an auto idling stop display unit 415, a hydraulic oil temperature display unit 416, a battery charge level display unit 417, a coolant temperature display unit 418, an operating time display unit 419, a camera image display unit 420, and a composite image display unit 422. The operation mode display unit 412, the driving mode display unit 413, the attachment display unit 414, and the auto idling stop display unit 415 are display units that display information related to the setting status of the shovel 200. The hydraulic oil temperature display unit 416, the battery charge level display unit 417, the coolant temperature display unit 418, and the operating time display unit 419 are display units that display information related to the operating status of the shovel 200. The images displayed in each unit are generated by the output device 50 using various data acquired by the shovel controller 30 and image data acquired by the imaging device 40.

[0109] The time display unit 411 displays the current time. The operation mode display unit 412 displays the operation mode for adjusting the power consumption of the electric motor 12 for the pump of the shovel 200. The travel mode display unit 413 displays the travel mode as operating information for the shovel 200. The travel mode represents the setting status of the travel hydraulic motor using a variable displacement motor. For example, the travel mode has a low-speed mode and a high-speed mode, with a mark shaped like a "turtle" displayed in low-speed mode and a mark shaped like a "rabbit" displayed in high-speed mode.

[0110] The attachment display unit 414 is an area that displays icons representing the type of attachment currently installed. The auto idling stop display unit 415 indicates whether or not to stop the pump motor 12 if the shovel 200 has not been operating for a certain period of time.

[0111] The hydraulic oil temperature display unit 416 displays the hydraulic oil temperature of the shovel 200. The hydraulic oil temperature may be obtained by a temperature sensor or the like (not shown). The battery charge level display unit 417 shows the charge level of the battery 192. In other words, the battery charge level display unit 417 shows the state of charge (SOC) of the battery 192. In the example shown in Figure 5, the battery charge level display unit 417 displays a bar gauge representing the current SOC of the battery 192. The SOC is displayed based on data output by the battery 192.

[0112] The cooling water temperature display unit 418 displays the water temperature of the cooling system that cools the electric motor 12 for the pump of the shovel 200, etc.

[0113] The operating time display unit 419 displays the cumulative operating time as operating information for the shovel 200. In the example shown in Figure 5, the operating time display unit 419 displays the cumulative operating time since the count was restarted by the operator, along with the unit "hr (hours)". The operating time display unit 419 may also display the lifetime operating time for the entire period after the shovel was manufactured, or the operating time for a specific section since the count was restarted by the operator.

[0114] The camera image display unit 420 displays images captured by the imaging device 40. In the example shown in Figure 5, the camera image display unit 420 displays images captured by the rear camera mounted on the upper rear end of the upper surface of the upper rotating body 3. The camera image display unit 420 may also display camera images captured by the left camera mounted on the upper left end or the right camera mounted on the upper right end of the upper surface of the upper rotating body 3. Alternatively, the camera image display unit 420 may display camera images captured by multiple cameras, including the left camera, right camera, and rear camera, arranged in a row.

[0115] Each camera may be positioned so that a portion of the image of the upper rotating body 3 is included in the camera image. Including a portion of the image of the upper rotating body 3 in the displayed image makes it easier for the operator to grasp the sense of distance between the object displayed on the camera image display unit 420 and the shovel 200. In the example shown in Figure 5, the camera image display unit 420 is displaying an image of the counterweight 3w of the upper rotating body 3.

[0116] The camera image display unit 420 displays a figure 421 that represents the orientation of the camera (rear camera) that captured the currently displayed camera image. Figure 421 consists of a shovel figure 421a representing the shape of the shovel 200 and a strip-shaped direction indicator figure 421b representing the shooting direction of the camera that captured the currently displayed camera image. Figure 421 is a display unit that displays information regarding the settings of the shovel 200.

[0117] In the example shown in Figure 5, the direction indicator figure 421b is displayed below the shovel figure 421a (on the opposite side of the figure representing attachment AT). This indicates that the image of the rear of the shovel 200, captured by the rear camera, is being displayed on the camera image display unit 420. For example, if the camera image display unit 420 is displaying an image captured by the right camera, the direction indicator figure 421b will be displayed to the right of the shovel figure 421a. Also, for example, if the camera image display unit 420 is displaying an image captured by the left camera, the direction indicator figure 421b will be displayed to the left of the shovel figure 421a.

[0118] The operator can switch the image displayed on the camera image display unit 420 to an image captured by another camera, for example, by pressing an image switching switch (not shown) located inside the cabin 10.

[0119] The composite image display unit 422 displays a composite image of multiple camera images captured by at least two of the multiple cameras (left camera, right camera, and rear camera). In the example shown in Figure 5, the composite image display unit 422 displays an overhead view image, which is a composite image of three camera images captured by the left camera, right camera, and rear camera, respectively, surrounding the left, rear, and right sides of the shovel figure. Alternatively, the composite image display unit 422 may display an overhead view image, which is a composite image of four camera images captured by the front camera, left camera, right camera, and rear camera, respectively, surrounding the front, left, rear, and right sides of the shovel figure.

[0120] Furthermore, the screen SC1A shown in Figure 5 includes a display area 510. The display area 510 displays information indicating that the battery 46 should be replaced, based on the status of the battery 46, as controlled by the notification control unit 305. Specifically, the display area 510 in Figure 5 displays the message "Please replace the battery." In addition, the display area 510 may not display anything if the voltage of the battery 46 exceeds the degradation threshold, and may only display a pop-up recommending the replacement of the battery 46 if the voltage of the battery 46 is below the degradation threshold. Alternatively, the display may be changed so that if the voltage of the battery 46 exceeds the degradation threshold, it displays that the battery 46 is normal, and if the voltage of the battery 46 is below the degradation threshold, it displays a recommendation to replace the battery 46.

[0121] In this embodiment, by displaying information recommending the replacement of the battery 46 based on its condition, the operator of the shovel 200 can be made aware that the battery 46 is deteriorating and needs to be replaced. In the case of a shovel whose power source is an engine, it is easy to recognize battery deterioration because the engine cannot be started when the battery deteriorates. On the other hand, in the case of an electric work machine, such as the shovel 200, whose power source is not an engine but a pump motor 12, it is difficult to recognize battery deterioration because even if the battery 46 is deteriorated, the machine can be started by supplying power to the shovel controller 30. Therefore, as described above, by detecting the condition of the battery 46 and displaying information recommending the replacement of the battery 46 if it is deteriorated, it becomes easier for the operator of the shovel 200 to recognize battery deterioration.

[0122] As described above, in a configuration in which a DC-DC converter 44 steps down the power supplied from the battery 192 and the battery 46 is charged by the power stepped down by the DC-DC converter 44, the shovel controller 30 may be configured to detect the state of the battery 46 before the DC-DC converter 44 is activated when the key cylinder 60 is operated, rather than detecting the state of the battery 46 before power is directly supplied from the battery 192 to the battery 46 when the key cylinder 60 is operated.

[0123] In this embodiment, the shovel 200 includes a battery 192 that supplies power to the shovel 200, a battery 46 that is charged by the power supplied from the battery 192, a key cylinder 60 for starting the shovel 200, and a shovel controller 30 that, when the key cylinder 60 is operated, supplies power from the battery 192 to make the shovel 200 operational. The shovel controller 30 detects the state of the battery 46 before starting to supply power from the battery 192 to the battery 46 when the key cylinder 60 is operated. This makes it easier for the operator of the shovel 200 to know the state of the battery 46.

[0124] Furthermore, in a configuration in which a DC-DC converter 44 steps down the power supplied from the battery 192, and the battery 46 is charged by the power stepped down by the DC-DC converter 44, the shovel controller 30 may detect the state of the battery 46 before the DC-DC converter 44 is activated when an operation is performed on the key cylinder 60 to make the shovel 200 operational. With this configuration, in a configuration in which a DC-DC converter 44 steps down the power supplied from the battery 192, and the battery 46 is charged by the power stepped down by the DC-DC converter 44, the state of the battery 46 can be detected using the timing before the DC-DC converter 44 is activated.

[0125] Furthermore, in the configuration described above, if the status of the battery 46 is notified via the output device 50, the status of the battery 46 can be directly notified to the operator operating the shovel 200.

[0126] Furthermore, as described above, if the output device 50 notifies the battery 46 of its deterioration a predetermined number of times, that is, if the battery 46 is not replaced despite being notified of its deterioration a predetermined number of times via the output device 50, the battery 192 may not supply power to the battery 46 even if the key cylinder 60 is operated to start the shovel 200. For example, the DC-DC converter 44 may not be activated even if the key cylinder 60 is operated to start the shovel 200. In that case, the power supply instruction unit 303 of the shovel controller 30 does not need to instruct the battery module 19 to activate the DC-DC converter 44. By using such a configuration, it is possible to avoid supplying power to the deteriorated battery 46.

[0127] (Other embodiments) Battery 46 experiences a voltage drop due to aging, and its voltage also decreases with longer periods of inactivity. Therefore, it is possible to determine whether the voltage drop is due to aging or the time spent inactive.

[0128] Figure 6 is a block diagram showing some other configuration examples of the shovel controller 30 shown in Figure 2.

[0129] As shown in Figure 6, the shovel controller 30 in this embodiment further includes a time measurement unit 306 compared to the one shown in Figure 3.

[0130] The time measurement unit 306 is an example of a measurement unit in the present invention. The time measurement unit 306 measures the elapsed time since the previous operation of the key cylinder 60.

[0131] Furthermore, in this embodiment, the notification control unit 305 determines whether the battery 46 is degraded based on the state of the battery 46 detected by the voltage measurement unit 302 and the elapsed time measured by the time measurement unit 306, and displays information corresponding to the determination result on the output device 50 via the output device 50.

[0132] Figure 7 is a flowchart illustrating the method for detecting the state of the battery 46 in this embodiment.

[0133] First, in this embodiment as well, the processes in steps ST11 to ST15 shown in Figure 4 are carried out in the same manner (steps ST21 to ST25).

[0134] In this embodiment, the time measurement unit 306 measures the elapsed time since the last operation on the key cylinder 60. Since the operation to start the shovel 200 was performed on the key cylinder 60 in step ST21, the last operation is the key operation to stop the shovel 200. When the key operation to stop the shovel 200 is performed, a signal indicating this may be sent from the key cylinder 60 to the shovel controller 30, or the time measurement unit 306 may recognize that the key operation to stop the shovel 200 has been performed by some other method. When the key operation to stop the shovel 200 is performed, the supply of power from the battery 192 to the battery 46 stops, and charging of the battery 46 ceases. In other words, the time measurement unit 306 measures the elapsed time since the supply of power from the battery 192 to the battery 46 stopped.

[0135] If the notification control unit 305 determines that the voltage measured in step ST23 is below the degradation threshold (YES in step ST25), it determines whether the elapsed time measured by the time measurement unit 306 is equal to or greater than a predetermined time (step ST26). Here, the predetermined time may be set according to the usage period of the battery 46. For example, the longer the usage period of the battery 46, the greater the degree of voltage drop when not in use, so the predetermined time may be set to be shorter.

[0136] If the elapsed time measured by the time measurement unit 306 is less than a predetermined time (YES in step ST26), the notification control unit 305 determines that the battery 46 is degraded and notifies the user via the output device 50 that it recommends replacing the battery 46 (step ST27).

[0137] On the other hand, if the elapsed time measured by the time measurement unit 306 is longer than a predetermined time (NO in step ST26), the notification control unit 305 determines that the battery is dead due to the long period of inactivity. In this case, the notification control unit 305 may, under its control, notify the user via the output device 50 that the battery is dead (step ST28).

[0138] In this embodiment, the time measurement unit 306 measures the elapsed time since the power supply from battery 192 to battery 46 was stopped, and the shovel controller 30 determines whether battery 46 is degraded based on the state of battery 46 and the elapsed time. With this configuration, when the voltage of battery 46 is low, it is possible to determine whether this is due to battery 46 degradation or to a so-called dead battery caused by prolonged inactivity. In this case, the time measurement unit 306 may measure the elapsed time as the time elapsed since the operation to stop the shovel 200 was performed on the key cylinder 60. This makes it possible to measure the elapsed time since the power supply from battery 192 to battery 46 was stopped based on the operation on the key cylinder 60.

[0139] Furthermore, the shovel controller 30 may determine whether the battery 46 is degraded based on the results of multiple past detections regarding the state of the battery 46. For example, the voltage measurement unit 302 may record a history of voltage measurement results that represent a numerical value indicating the state of the battery 46 in the shovel controller 30, and the shovel controller 30 may determine that the battery 46 is degraded based on the degree of voltage change, such as when the voltage drops sharply in multiple past detection results in this history. With such a configuration, the state of the battery 46 can be recognized even more accurately.

[0140] In the embodiment described above, the state of the battery 46 is detected by measuring the voltage of the battery 46. However, the state of the battery 46 may also be detected by measuring the specific gravity of the battery fluid in the battery 46. In this case, it is preferable to detect and notify the operator of the shovel 200 of the state of the battery 46 while the operator is in the cabin 10. [Explanation of Symbols]

[0141] 1. Lower running body 1L, 1R Hydraulic Motor for Travel 2. Swivel mechanism 2M Swivel Hydraulic Motor 3. Upper rotating body 4 Boom 5 Arms 6 buckets 7 Boom Cylinder 8 Arm Cylinder 9 Bucket Cylinder 10 cabins 12 Electric motors for pumps 12s1 Current Sensor 12s2 Voltage Sensor 12s3 Rotation Status Sensor 14 Main pump 15 Pilot pump 16 High-pressure hydraulic line 17 Control valve 18 Inverters 19 Battery Modules 25 Pilot Line 26 Operating device 26A~26C Lever 28 signal lines 30 Shovel Controller 31 Pressure control valve 40 Imaging device 44 DC-DC converters 46,192 batteries 50 Output device 52 Input devices 60 Key Cylinders 80 Air conditioner 81 Air Conditioning Controller 191 Battery Controller 200 Shovel 301 Start signal receiving unit 302 Voltage Measurement Section 303 Power supply instruction section 304 Motor drive instruction unit 305 Notification Control Unit 306 Time Measurement Unit T Hydraulic oil tank

Claims

1. Electric power machinery, A high-voltage battery that supplies power to the electric work machine, A low-voltage battery that is charged by power supplied from the aforementioned high-voltage battery, A starting device for starting the aforementioned electric work machine, The system includes a control device that, when the starting device is operated, supplies power from the high-voltage battery to make the electric work machine operational, The control device detects the state of the low-voltage battery before starting to supply power from the high-voltage battery to the low-voltage battery when an operation is performed on the starting device, in an electric work machine.

2. It has a step-down converter that reduces the voltage of the power supplied from the high-voltage battery, The low-voltage battery is charged by the power stepped down by the step-down converter. The electric work machine according to claim 1, wherein the control device detects the state of the low-voltage battery before the step-down converter is activated when an operation is performed on the starting device to make the electric work machine operational.

3. The electric work machine according to claim 1, further comprising a notification device for notifying the status of the low-voltage battery.

4. The electric work machine according to claim 3, wherein the control device does not supply power from the high-voltage battery to the low-voltage battery if the notification device notifies the low-voltage battery a predetermined number of times that the low-voltage battery is degraded.

5. It has a measuring unit that measures the elapsed time since the supply of power from the high-voltage battery to the low-voltage battery stopped, The electric work machine according to claim 1, wherein the control device determines whether the low-voltage battery is degraded based on the state of the low-voltage battery and the elapsed time.

6. The electric work machine according to claim 5, wherein the measuring unit measures the time elapsed since the operation to stop the electric work machine on the starting device as the elapsed time.

7. The electric work machine according to claim 1, wherein the control device determines whether the low-voltage battery is degraded based on the results of multiple past detections regarding the state of the low-voltage battery.

8. The electric work machine according to claim 7, wherein the control device determines whether the low-voltage battery is degraded based on the degree of change in the numerical value indicating the state of the low-voltage battery in the multiple past detection results.

Images