Electric work machine

Abstract

To provide an electric working machine allowing an operator to quickly perform appropriate maintenance.SOLUTION: The electric work machine includes a charger configured to supply electric power from an external power supply to a battery to charge the battery, an electric motor configured to be driven by the electric power supplied from the battery, a control unit configured to manage a physical quantity indicating an operating state of the electric motor as first operating information and manage a physical quantity indicating an operating state including charging and discharging of the battery as second operating information, and a display unit configured to display the first operating information and the second operating information. The control unit determines whether or not at least one of the physical quantity managed as the first operation information and the physical quantity managed as the second operation information has reached a specified value, and in a case where the physical quantity has reached the specified value, the control unit causes the display unit to display that the physical quantity has reached the specified value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electric work machine. [Background technology]

[0002] Conventionally, maintenance notification devices for construction machinery have been disclosed. For example, the notification device in Patent Document 1 notifies the driver or manager that the actual operating time of the engine has reached the maintenance time for each maintenance item. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-262806 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in addition to hydraulic excavators that use engine power to drive hydraulic actuators, hydraulic excavators that use battery power to drive hydraulic actuators (electric excavators) have also become widely used. In electric excavators, battery power is used to drive an electric motor, which rotates a hydraulic pump, which supplies pressure oil to the hydraulic actuator to drive it.

[0005] An object of the present invention is to provide an electric working machine that allows an operator to quickly perform appropriate maintenance. [Means for solving the problem]

[0006] An electric working machine according to one aspect of the present invention includes a charger that supplies power from an external power source to a battery to charge the battery; an electric motor that is driven by the power supplied from the battery; a control unit that manages physical quantities that indicate the operating state of the electric motor as first operation information and manages physical quantities that indicate the operating state including charging and discharging of the battery as second operation information; and a display unit that displays the first operation information and the second operation information, wherein the control unit determines whether at least one of the physical quantities managed as the first operation information and the physical quantity managed as the second operation information has reached a specified value, and if the specified value has been reached, causes the display unit to display that the specified value has been reached. [Effects of the Invention]

[0007] According to the above configuration, the operator can quickly perform appropriate maintenance. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view showing a schematic configuration of a hydraulic excavator, which is an example of an electric work machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram schematically showing the configuration of a control system and a hydraulic system of the hydraulic excavator. [Figure 3] FIG. 2 is an explanatory diagram showing an example of a display on a display unit of the hydraulic excavator. [Figure 4] 10A and 10B are explanatory diagrams showing other examples of the display on the display unit. [Figure 5] 5A and 5B are explanatory diagrams each showing an example of a current-carrying state of a relay, an operating state of an electric motor, an operating state of a charger, and an operating state of a battery in a charging mode and a battery mode, respectively; [Figure 6] 10A and 10B are explanatory diagrams schematically illustrating an example of the energized state of a relay, the operating state of an electric motor, the operating state of a charger, and the operating state of a battery in a charging mode, a battery mode, and a combined power supply mode, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes an embodiment of the present invention with reference to the drawings.

[0010] [1. Electric working machines] 1 is a side view showing a schematic configuration of a hydraulic excavator 1 constituting an electric shovel, which is an example of an electric work machine according to this embodiment. The hydraulic excavator 1 includes a lower traveling body 2, a work implement 3, and an upper rotating body 4.

[0011] Here, directions in FIG. 1 are defined as follows. First, the direction in which the lower traveling body 2 moves straight is the fore-and-aft direction, with one side of this being the "front" and the other side being the "rear." In FIG. 1, as an example, the side of the traveling motor 22 relative to the blade 23 is shown as the "front." Furthermore, the lateral direction perpendicular to the fore-and-aft direction is the left-and-right direction. In this case, the left side as seen from the operator (pilot, driver) sitting in the cockpit 41a is defined as the "left," and the right side is defined as the "right." Furthermore, the direction of gravity perpendicular to the fore-and-aft direction and the left-and-right direction is defined as the up-and-down direction, with the upstream side of the direction of gravity being defined as the "up" and the downstream side being defined as the "down."

[0012] The lower traveling structure 2 is equipped with a pair of left and right crawlers 21 and a pair of left and right traveling motors 22. Each traveling motor 22 is a hydraulic motor. The left and right traveling motors 22 drive the left and right crawlers 21, respectively, to move the hydraulic excavator 1 forward and backward. The lower traveling structure 2 is provided with a blade 23 for performing ground leveling work and a blade cylinder 23a. The blade cylinder 23a is a hydraulic cylinder that rotates the blade 23 up and down.

[0013] The work implement 3 includes a boom 31, an arm 32, and a bucket 33. By independently driving the boom 31, the arm 32, and the bucket 33, it is possible to perform work of excavating earth and sand, etc.

[0014] The boom 31 is rotated by a boom cylinder 31a. The base end of the boom cylinder 31a is supported on the front part of the upper rotating body 4 and is movable so as to be telescopic. The arm 32 is rotated by an arm cylinder 32a. The base end of the arm cylinder 32a is supported on the tip part of the boom 31 and is movable so as to be telescopic. The bucket 33 is rotated by a bucket cylinder 33a. The base end of the bucket cylinder 33a is supported on the tip part of the arm 32 and is movable so as to be telescopic. The boom cylinder 31a, arm cylinder 32a, and bucket cylinder 33a are constituted by hydraulic cylinders.

[0015] The upper rotating body 4 is configured to be rotatable via a slewing bearing (not shown) relative to the lower traveling body 2. A control unit 41, a swivel base 42, a slewing motor 43, an engine room 44, etc. are arranged on the upper rotating body 4. The upper rotating body 4 rotates via the slewing bearing by driving the slewing motor 43, which is a hydraulic motor.

[0016] A plurality of hydraulic pumps 71 (see FIG. 2) are arranged on the upper rotating body 4. Each hydraulic pump 71 is driven by an electric motor 61 (see FIG. 2) inside the engine room 44. Each hydraulic pump 71 supplies hydraulic oil (pressurized oil) to hydraulic motors (e.g., left and right travel motors 22, swing motor 43) and hydraulic cylinders (e.g., blade cylinder 23a, boom cylinder 31a, arm cylinder 32a, bucket cylinder 33a). The hydraulic motors and hydraulic cylinders that are driven by the supply of hydraulic oil from any of the hydraulic pumps 71 are collectively referred to as hydraulic actuators 73 (see FIG. 2).

[0017] A control seat 41a is arranged in the control section 41. Various levers 41b are arranged around the control seat 41a. An operator sits in the control seat 41a and operates the levers 41b to drive the hydraulic actuator 73. This allows the lower traveling body 2 to travel, the blade 23 to perform ground leveling work, the work implement 3 to perform excavation work, the upper rotating body 4 to rotate, and so on.

[0018] A battery 53 is attached to the upper rotating body 4. The battery 53 is formed, for example, by a lithium-ion battery that outputs high voltage, and is used to drive the electric motor 61. The upper rotating body 4 is also provided with a power supply port (not shown). The power supply port and the external power source 51 are connected via a power supply cable 52. This makes it possible to charge the battery 53.

[0019] When the lower traveling body 2, the work implement 3, and the upper rotating body 4 are collectively referred to as the machine body BA, the machine body BA may be driven by a combination of electrically driven equipment and hydraulic equipment. In other words, the machine body BA may include hydraulic equipment such as the hydraulic actuator 73, as well as an electric travel motor, an electric cylinder, an electric swing motor, etc.

[0020] [2. Control and hydraulic system configuration] FIG. 2 is a block diagram showing a schematic configuration of the control system and hydraulic system of the hydraulic excavator 1. In FIG. 2, dashed arrows indicate transmission paths for detection signals, and solid arrows indicate transmission paths for control signals (commands). The hydraulic excavator 1 is equipped with an electric motor 61. The electric motor 61 is driven by power supplied from a battery 53.

[0021] The rotation speed of the electric motor 61 is detected by a rotation speed detection sensor 61a. That is, the hydraulic excavator 1 is provided with a rotation speed detection sensor 61a that detects the rotation speed of the electric motor 61. Information about the rotation speed of the electric motor 61 detected by the rotation speed detection sensor 61a is input to an ECU 80, which will be described later.

[0022] The hydraulic excavator 1 is equipped with a charger 62. The charger 62 converts AC voltage supplied from the external power source 51 via a power supply cable 52 (see FIG. 1) into DC voltage. The DC voltage (electric power) output from the charger 62 is supplied to the battery 53. The battery 53 is charged by the power being supplied from the external power source 51 to the battery 53 via the charger 62. In other words, the hydraulic excavator 1 is equipped with the charger 62 that supplies power from the external power source 51 to the battery 53 to charge the battery 53.

[0023] The hydraulic excavator 1 includes an inverter 63. The inverter 63 converts DC voltage supplied from the battery 53 into AC voltage and supplies it to the electric motor 61. This causes the electric motor 61 to rotate. The supply of AC voltage (current) from the inverter 63 to the electric motor 61 is performed based on a rotation command (control signal) output from the ECU 80.

[0024] Electric power supplied from the battery 53 to the electric motor 61 passes through a first electric circuit E1. The inverter 63 described above is located between the battery 53 and the electric motor 61 on the first electric circuit E1. Electric power supplied from the charger 62 to the battery 53 passes through a second electric circuit E2. The second electric circuit E2 joins the first electric circuit E1 at a junction Ec located between the battery 53 and the inverter 63. Therefore, electric power output from the charger 62 is supplied to the battery 53 via the second electric circuit E2 and the junction Ec. In other words, the hydraulic excavator 1 includes a first electric circuit E1 that supplies electric power from the battery 53 to the electric motor 61, and a second electric circuit E2 that is connected to the charger 62 and joins the first electric circuit E1 at the junction Ec.

[0025] The hydraulic excavator 1 also includes a relay 64. The relay 64 is located in the first electric circuit E1 between the junction Ec and the battery 53. The relay 64 switches the first electric circuit E1 between a connected state (electrically connecting the battery 53 and the inverter 63) and a disconnected state (electrically disconnecting the battery 53 and the inverter 63) based on the control of the ECU 80. The relay 64 detects the connected state or the disconnected state and outputs a detection signal to the ECU 80. This allows the ECU 80 to manage the connected or disconnected time of the relay 64 based on the detection signal.

[0026] The hydraulic excavator 1 also includes a hydraulic system 70. The hydraulic system 70 includes a hydraulic pump 71, a control valve 72, and a hydraulic actuator 73.

[0027] The hydraulic pump 71 is connected to the rotary shaft (output shaft) of the electric motor 61 and is driven by the rotation of the electric motor 61. The hydraulic pump 71 is, for example, a variable displacement pump, but may also be a fixed displacement pump. As described above, a plurality of hydraulic pumps 71 are provided, but FIG. 2 shows only one hydraulic pump 71 as an example. The hydraulic pump 71 supplies hydraulic oil in a hydraulic oil tank (not shown) as pressurized oil to hydraulic actuators 73 via control valves 72. This drives the hydraulic actuators 73. The control valves 72 are directional switching valves that control the flow direction and flow rate of the pressurized oil supplied from the hydraulic pump 71 to the hydraulic actuators 73, and are provided corresponding to each hydraulic actuator 73.

[0028] As described above, the hydraulic excavator 1 is provided with a hydraulic system 70 including a hydraulic pump 71 driven by the electric motor 61 and a hydraulic actuator 73 to which pressure oil is supplied by the hydraulic pump 71 .

[0029] The hydraulic excavator 1 further includes an ECU (Electronic Control Unit) 80. The ECU 80 is a control unit that controls each part of the hydraulic excavator 1, and is configured to include, for example, a CPU (Central Processing Unit), a storage unit, etc. The ECU 80 generates a rotation command for the electric motor 61 and supplies the command to the inverter 63.

[0030] Furthermore, detection signals are input to the ECU 80 from each part of the hydraulic excavator 1. For example, the electric motor 61, the charger 62, the inverter 63, and the battery 53 each have a built-in sensor (not shown) that detects their own operating state, including the presence or absence of an abnormality, and detection signals from these sensors are input to the ECU 80. This allows the ECU 80 to recognize the operating state of each of the electric motor 61, the charger 62, the inverter 63, and the battery 53 based on the above detection signals.

[0031] For example, based on a detection signal from a sensor built into the electric motor 61, the ECU 80 can recognize the time during which the electric motor 61 is driven as the operating time of the electric motor 61. Furthermore, based on a detection signal from a sensor built into the charger 62, the ECU 80 can recognize the time during which the charger 62 is operating (e.g., the charging time of the battery 53). Furthermore, based on a detection signal from a sensor built into the battery 53, the ECU 80 can recognize the time during which the battery 53 is operating (e.g., the charging time and discharging time of the battery 53), and can also recognize the remaining capacity (charge amount) of the battery 53.

[0032] The ECU 80 stores and manages the first operation information and the second operation information in a storage unit within the ECU 80. The first operation information is information on physical quantities indicating the operation state of the electric motor 61, and includes, for example, the operation time of the electric motor 61 described above. The first operation information may include information on the rotation speed of the electric motor 61 detected by the rotation speed detection sensor 61a. On the other hand, the second operation information is information on physical quantities indicating the operation state of the battery 53, and includes, for example, the operation time (charge time+discharge time) of the battery 53 described above. The second operation information may include the remaining capacity of the battery 53.

[0033] In this way, the hydraulic excavator 1 is equipped with an ECU 80 as a control unit that manages physical quantities indicating the operating state of the electric motor 61 as first operating information based on the output signal of the electric motor 61, and manages physical quantities indicating the operating state including charging and discharging of the battery 53 as second operating information based on the output signal of the battery 53.

[0034] The hydraulic excavator 1 further includes an output unit 90. The output unit 90 outputs the first operation information and the second operation information managed by the ECU 80. The output unit 90 includes a display unit 91 and a communication unit 92.

[0035] The display unit 91 is configured with, for example, a liquid crystal display device, and displays the first operation information and the second operation information under the control of the ECU 80. That is, the output unit 90 includes the display unit 91 that displays the first operation information and the second operation information. The communication unit 92 is an interface for communicating with an external terminal, and is configured to include an antenna, a transmission / reception circuit, etc.

[0036] Although not shown, the hydraulic excavator 1 is provided with a hydraulic oil temperature sensor that detects the temperature of the hydraulic oil described above, and a cooling water temperature sensor that detects the temperature of the cooling water flowing through a cooling system for cooling the electric motor 61, etc.

[0037] FIG. 3 shows an example of the display on the display unit 91. As shown in the figure, the display unit 91 displays information 101 to 103, respectively, including the hydraulic oil temperature detected by the hydraulic oil temperature sensor, the remaining charge of the battery 53, and the coolant temperature detected by the coolant temperature sensor. Additionally, the display unit 91 displays the operating time T1 of the electric motor 61 as first operating information together with an icon M1 indicating the electric motor 61, and displays the operating time T2 of the battery 53 as second operating information together with an icon M2 indicating the battery 53. In the example shown in the figure, the operating time T1 is shown to be "300 hours," and the operating time T2 is shown to be "500 hours." Note that "H" indicates time (hours) (the same applies hereinafter).

[0038] As in the present embodiment, the ECU 80 manages a physical quantity indicating the operating state of the electric motor 61 (e.g., operating time T1 of the electric motor 61) as first operating information, and manages a physical quantity indicating the operating state of the battery 53, including charging and discharging, as second operating information (e.g., operating time T2 = charging time + discharging time). In this case, the output unit 90 outputs the first operating information, which allows an operator or the like (the operator, a nearby worker, a system administrator, or the like) to perform maintenance (inspection) of the hydraulic system 70 (e.g., the hydraulic pump 71) at an appropriate timing based on the output first operating information. Furthermore, the output unit 90 outputs the second operating information, which allows an operator or the like to perform maintenance of the battery 53 at an appropriate timing that takes into consideration not only deterioration of the battery 53 during discharging but also deterioration during charging, i.e., at an appropriate timing independent of the timing of maintenance of the hydraulic system 70, based on the second operating information, and also allows the operator or the like to replace the battery 53 as needed.

[0039] In particular, the physical quantity indicating the operating state of the electric motor 61 includes the operating time T1 of the electric motor 61. Because the hydraulic pump 71 is driven by the electric motor 61, the operating time of the hydraulic system 70 including the hydraulic pump 71 is considered to be substantially the same as the operating time of the electric motor 61. Therefore, by the ECU 80 managing the operating time T1 of the electric motor 61 as the first operating information, when the output unit 90 outputs the first operating information, an operator or the like can perform maintenance of the hydraulic system 70 at an appropriate time based on the first operating information, that is, the operating time of the electric motor 61.

[0040] Furthermore, the physical quantity indicating the operating state of the battery 53 includes the sum of the charging time and discharging time of the battery 53. In this case, when the output unit 90 outputs the second operation information, the operator or the like can perform maintenance of the battery 53 at an appropriate timing based on the sum of the charging time and discharging time of the battery 53. In other words, maintenance of the battery 53 can be performed at an appropriate timing that takes into consideration not only deterioration of the battery 53 during discharging but also deterioration during charging.

[0041] The physical quantity indicating the operating state of the battery 53 is not limited to the sum of the charging time and discharging time of the battery 53. For example, the sum of a total charge amount (absolute value) obtained by integrating the charge amount of the battery 53 over a predetermined period for each of the predetermined periods and a total discharge amount (absolute value) obtained by integrating the discharge amount of the battery 53 over a predetermined period for each of the predetermined periods may be treated as the physical quantity indicating the operating state of the battery 53. Even in this case, when the output unit 90 outputs the second operating information, an operator or the like can perform maintenance on the battery 53 at an appropriate timing that takes into consideration not only deterioration due to discharging of the battery 53 but also deterioration due to charging, based on the output second operating information, that is, the sum of the total charge amount and the total discharge amount of the battery 53.

[0042] Furthermore, in this embodiment, the output unit 90 includes a display unit 91 that displays the first operation information and the second operation information. This allows, for example, an operator to easily determine the timing to perform maintenance on the hydraulic system 70 by looking at the first operation information (e.g., operation time T1) displayed on the display unit 91, and also to easily determine the timing to perform maintenance on the battery 53 by looking at the second operation information (e.g., operation time T2) displayed on the display unit 91.

[0043] In the present embodiment, the output unit 90 also includes a communication unit 92. In this configuration, the ECU 80 outputs the first operation information and the second operation information to an external terminal via the communication unit 92, allowing a system administrator who handles the terminal to recognize the first operation information and the second operation information. This allows the administrator to appropriately manage the timing of maintenance of the hydraulic system 70 based on the first operation information, and furthermore, to appropriately manage the timing of maintenance taking into account deterioration due to discharging and charging of the battery 53 based on the second operation information.

[0044] Meanwhile, the ECU 80 may determine whether at least one of the physical quantities managed as the first operation information and the second operation information has reached a specified value, and if the specified value has been reached, cause the display unit 91 to display that the specified value has been reached. For example, FIG. 4 shows another example of a display on the display unit 91. In this example, when the operation time T1 of the electric motor 61 reaches a first specified value (e.g., 600 hours), the display unit 91 flashes the operation time T1 to notify the user that the operation time T1 has reached the first specified value. In addition, in this example, when the operation time T2 of the battery 53 reaches a second specified value (e.g., 1000 hours), the display unit 91 flashes the operation time T2 to notify the user that the operation time T2 has reached the second specified value.

[0045] In this way, by ECU 80 controlling the display on display unit 91, the operator can see on display unit 91 and immediately understand that the physical quantity managed as the first operation information or the second operation information has reached a specified value, and can easily recognize that it is time to perform maintenance on at least one of hydraulic system 70 and battery 53. This enables the operator to quickly perform appropriate maintenance, such as inspecting hydraulic pump 71 or replacing battery 53.

[0046] 4 shows an example in which the operation times T1 and T2 of the electric motor 61 reach their respective specified values ​​(first specified value and second specified value) at the same time, but they do not necessarily reach the same value at the same time. In other words, when at least one of the operation times T1 and T2 reaches the specified value, the ECU 80 may notify the user that the specified value has been reached by causing the display unit 91 to flash the operation time that has reached the specified value.

[0047] Incidentally, it is desirable that the ECU 80 manages, as the first operation information, a physical quantity that indicates the operating state of the electric motor 61 in a state in which the rotation speed of the electric motor 61 detected by the rotation speed detection sensor 61a exceeds a predetermined value (for example, 10 rotations / min). In this case, the ECU 80 will display, on the display screen of the display unit 91 shown in Figures 3 and 4, as the operating time T1 of the electric motor 61, the time during which the electric motor 61 is operating in a state in which the rotation speed of the electric motor 61 exceeds the predetermined value.

[0048] By managing the first operation information as described above, the ECU 80 can exclude from the first operation information of the electric motor 61 the operation time during which the electric motor 61 is rotating at a rotation speed below the predetermined value (for example, an extremely low speed) and cannot be considered to be substantially operating, and can manage as the first operation information the operation time during which the electric motor 61 is considered to be substantially rotating at a rotation speed exceeding the predetermined value. This can improve the accuracy of management of the timing of maintenance of the electric motor 61 based on the first operation information.

[0049] [3. How to obtain physical quantities that indicate the operating status of the battery] The drive modes of the hydraulic excavator 1 in this embodiment include a charge mode and a battery mode. The charge mode is an operation mode in which the battery 53 is charged by the charger 62. On the other hand, the battery mode is an operation mode in which the electric motor 61 is driven by power from the battery 53.

[0050] 5 schematically shows an example of the state (connected state / disconnected state) of the relay 64, the operating state of the electric motor 61, the operating state of the charger 62, and the operating state of the battery 53 in each of the charge mode and the battery mode. When the hydraulic excavator 1 is driven in two drive modes, the charge mode and the battery mode, in the charge mode, the battery 53 is charged by the operation of the charger 62, so the operating time (2) of the charger 62 is the same as the charging time (3) of the battery 53. On the other hand, in the battery mode, the battery 53 is discharged by the operation of the electric motor 61, so the operating time (1) of the electric motor 61 is the same as the discharging time (4) of the battery 53. Therefore, the sum of the charging time (3) and the discharging time (4) of the battery 53 is equal to the sum of the operating time (2) of the charger 62 and the operating time (1) of the electric motor 61. In other words, the physical quantity indicating the operating state including charging and discharging of battery 53 (charging time (3) of battery 53 + discharging time (4) of battery 53) is the sum of the operating time (2) of charger 62 and the operating time (1) of electric motor 61.

[0051] Therefore, when the hydraulic excavator 1 is driven in the charge mode or the battery mode as described above, the ECU 80 can easily acquire and manage the physical quantity (charge time (3) + discharge time (4)) indicating the operating state of the battery 53 by managing the sum of the operating time (2) of the charger 62 and the operating time (1) of the electric motor 61.

[0052] [4. Other methods for obtaining physical quantities indicating the operating status of the battery] The drive modes of the hydraulic excavator 1 may include a combined power supply mode in addition to the above-described charge mode and battery mode. The combined power supply mode is a mode in which the electric motor 61 is driven by power supplied from at least one of the external power supply 51 and the battery 53.

[0053] 6 schematically shows an example of the state (connected state / disconnected state) of the relay 64, the operating state of the electric motor 61, the operating state of the charger 62, and the operating state of the battery 53 in each of the charge mode, battery mode, and combined power source mode. When the hydraulic excavator 1 is driven in the three drive modes of the charge mode, battery mode, and combined power source mode, the physical quantity indicating the operating state including the charging and discharging of the battery 53 (charging time (D) of the battery 53+discharging time (E) of the battery 53) is not the sum of the operating time (C) of the charger 62 and the operating time (B) of the electric motor 61, and therefore does not have the same relationship as in FIG. 5.

[0054] However, in the charge mode, battery mode, and combined power supply mode, battery 53 is charged or discharged, and both charging and discharging are performed with relay 64 connected. Therefore, the sum of the charging time (D) and discharging time (E) of battery 53 is equal to the connection time (A) of relay 64. In other words, the physical quantity indicating the operating state including charging and discharging of battery 53 (charging time (D) of battery 53 + discharging time (E) of battery 53) is the connection time (A) of relay 64.

[0055] Therefore, when the hydraulic excavator 1 is driven in the charge mode, battery mode or combined power supply mode as described above, the ECU 80 can easily acquire and manage the physical quantity (charge time (D) + discharge time (E)) indicating the operating state of the battery 53 by managing the connection time (A) of the relay 64.

[0056] The relationship in which the charge time (D) plus the discharge time (E) of the battery 53 is equal to the connection time (A) of the relay 64 can also be seen in Figure 5. In other words, when the hydraulic excavator 1 is driven in two drive modes, that is, the charge mode and the battery mode, the relay 64 is in the connected state in both the charge mode and the discharge mode, and therefore in Figure 5 the sum of the charge time (3) and the discharge time (4) of the battery 53 is equal to the connection time (5) of the relay 64. Therefore, the above-mentioned effect of being able to easily acquire and manage the physical quantity indicating the operating state of the battery 53 by the ECU 80 managing the connection time of the relay 64 can be obtained even when the hydraulic excavator 1 is driven in two drive modes (the charge mode or the battery mode) as shown in Figure 5.

[0057] In the above, a hydraulic excavator, which is a construction machine, has been used as an example of an electrically powered work machine, but the work machine is not limited to a hydraulic excavator and may be other construction machinery such as a wheel loader, or agricultural machinery such as a combine harvester or a tractor.

[0058] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these, and the invention can be expanded or modified without departing from the spirit of the invention. [Industrial Applicability]

[0059] The present invention can be used in work machines such as construction machines and agricultural machines. [Explanation of symbols]

[0060] 1. Hydraulic excavator (electric powered work machine) 51 External power supply 53 Battery 61 Electric motor 62 Charger 61a Rotation speed detection sensor 64 Relay 70 Hydraulic System 71 Hydraulic pump 73 Hydraulic Actuator 80 ECU (control unit) 90 Output Department 91 indicates the department E1 Circuit 1 E2 Circuit 2 Ec confluence

Claims

1. a charger that supplies power from an external power source to the battery to charge the battery; an electric motor driven by power supplied from the battery; a control unit that manages a physical quantity indicating an operation state of the electric motor as first operation information and manages a physical quantity indicating an operation state including charging and discharging of the battery as second operation information; a display unit that displays the first operation information and the second operation information, the control unit determines whether at least one of the physical quantity managed as the first operation information and the physical quantity managed as the second operation information has reached a specified value, and, if the specified value has been reached, causes the display unit to display that the specified value has been reached.

2. The electric working machine according to claim 1 , wherein when at least one of the first operation information and the second operation information reaches the specified value, the display unit notifies the user by flashing the corresponding operation information.

3. The electric working machine according to claim 1 or 2, wherein the display unit displays the first operation information and the second operation information together with icons representing the electric motor and the battery, respectively.

4. The electric working machine according to claim 1 , wherein the control unit outputs the first operation information and the second operation information to an external terminal via a communication unit.

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