Shovel

Abstract

To provide a motor-driven shovel that is capable of being moved even when a control device fails.SOLUTION: A shovel comprises: an activation device activating the shovel; an activation reserve device activating the shovel with means different from the activation device; and a control device activating the shovel upon operation of the activation device, wherein activating the shovel with the activation reserve device makes the shovel activated without going through the control device, and functions of the shovel are limited more than when the activation device activates the shovel.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to an excavator.

Background Art

[0002] Conventionally, an electric excavator in which a hydraulic pump is driven to operate by the rotation of an electric motor is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the start switch of an electric excavator is operated and a start signal is input to the control device, electric power from a high-voltage power source is supplied to the electric motor, the electric motor rotates, and the hydraulic pump is driven to enable operation.

[0005] Therefore, if a failure occurs in the start switch or the control device, the electric excavator cannot be started. In that case, even if an error code or the like indicates that a failure has occurred, the electric excavator must wait in a non-operable state until rescue such as repair arrives.

[0006] Therefore, it is preferable to enable the excavator to be operated even when a failure occurs in the control device.

Means for Solving the Problems

[0007] To achieve the above object, the present disclosure provides an excavator, a starting device for starting the excavator, a backup starting device for starting the excavator by means different from the starting device a control device that starts the excavator when an operation on the starting device is performed; When the excavator is started by the starting standby device, the excavator starts without passing through the control device, and the functions of the excavator are restricted compared to the case where the excavator is started by the starting device.

Advantages of the Invention

[0008] According to the present disclosure, the electric excavator can be moved even when a failure occurs in the control device.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Best Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are illustrative rather than limiting the invention, and not all features and combinations thereof described in the embodiments are necessarily essential to the invention. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and the description thereof may be omitted.

[0011] First, as an example of an electric excavator, an outline of an excavator 200 according to an embodiment will be described.

[0012] [Outline of Excavator] FIG. 1 is a side view showing the excavator according to the present embodiment.

[0013] As shown in FIG. 1, the excavator 200 according to the present embodiment includes a lower traveling body 1, an upper swing body 3 mounted on the lower traveling body 1 so as to be swingable via a swing mechanism 2, a boom 4, an arm 5, and a bucket 6 as attachments, and a cabin 10.

[0014] The lower traveling body 1 includes, for example, a pair of left and right crawlers, and each crawler is self-propelled by being hydraulically driven by traveling hydraulic motors 1R and 1L (see FIG. 2).

[0015] 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 the 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). The excavator 200 is an electric excavator having a configuration in which a power source (engine) of a so-called hydraulic excavator is replaced with a pump motor 12 (see FIG. 2).

[0016] Further, 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 (see FIG. 2) instead of the swing hydraulic motor 2M through the swing mechanism 2. In this case, for example, the excavator 200 is connected from the battery module 19 to the swing electric motor via an inverter 18 (see FIG. 2). 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 electric power to swing-brake the upper swing body 3 under the control of the excavator controller 30 and the inverter 18. Further, the swing electric motor may supply the regenerative electric power to the battery module 19 or the pump electric motor 12 via the inverter 18.

[0017] The boom 4 is pivotally attached to the front center of the upper swing body 3 so as to be able to pitch. An arm 5 is pivotally attached to the tip of the boom 4 so as to be able to rotate vertically, and a bucket 6 is pivotally 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.

[0018] The bucket 6 is an example of an end attachment, and 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 type different 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 type different from the bucket such as a breaker, a stirrer, or a grapple.

[0019] The cab 10 is mounted on the front left side of the upper swing body 3, and inside thereof (the interior), there are provided a driver's seat on which an operator sits, an operation device 26 (see FIG. 2) described later, and the like.

[0020] The excavator 200 operates driven elements such as the lower traveling body 1 (left and right crawlers), the upper swing body 3, the boom 4, the arm 5, and the bucket 6 according to the operation of an operator boarding the cab 10.

[0021] Further, instead of or in addition to being configured to be operable by an operator boarding the cab 10, the excavator 200 may be configured to be remotely operated from outside the excavator 200. When the excavator 200 is remotely operated, the inside of the cab 10 may be unmanned. Hereinafter, the description will proceed on the premise that the operation by the operator includes at least one of the operation on the operating device 26 of the operator in the cab 10 and the remote operation by an external operator.

[0022] The remote operation includes, for example, a mode in which the excavator 200 is operated by an operation input regarding an actuator of the excavator 200 performed by a predetermined external device. In this case, the excavator 200 is equipped with a communication device (not shown) capable of communicating with the predetermined external device, and may transmit, for example, image information (captured image) output by an imaging device (not shown) to the external device. Then, the external device may display the received image information (captured image) on a display device provided in the own device (hereinafter, "remote operation display device"). Also, various information images (information screens) displayed on the output device 50 (see FIG. 2) inside the cab 10 of the excavator 200 may similarly be displayed on the remote operation display device of the external device. Thereby, an operator of the external device can remotely operate the excavator 200 while checking display contents such as a captured image or an information screen showing the state around the excavator 200 displayed on the remote operation display device. Then, the excavator 200 operates the hydraulic actuator according to a remote operation signal received from the external device by the communication device, and drives driven elements such as the lower traveling body 1 (left and right crawlers), the upper swing body 3, the boom 4, the arm 5, and the bucket 6.

[0023] In addition, remote operation may include, for example, a mode in which the excavator 200 is operated by external voice input or gesture input from a person (e.g., an operator) around the excavator 200 to the excavator 200. Specifically, the excavator 200 recognizes voices spoken by surrounding workers or gestures made by workers through a voice input device (e.g., a microphone) or a gesture input device (e.g., an imaging device) mounted on the excavator 200 (itself). Then, the excavator 200 may operate the actuator according to the recognized voice, gesture, etc., and 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.

[0024] Further, the excavator 200 may automatically operate the actuator regardless of the content of the operator's operation. Thereby, the excavator 200 realizes a function (so-called "automatic driving function" or "machine control function") of automatically operating at least a part of 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] The automatic driving function may include a function (so-called "semiautomatic driving function") that automatically operates driven elements (actuators) other than the driven element (hydraulic actuator) of the operation target in response to an operation on the operator's operation device 26 or a remote operation. Further, the automatic driving function may include a function (so-called "fully automatic driving function") that automatically operates at least a part of a plurality of driven elements (actuators) on the premise that there is no operation on the operator's operation device 26 or a remote operation. In the excavator 200, when the fully automatic driving function is valid, the inside of the cab 10 may be unmanned. Further, the semiautomatic driving function, the fully automatic driving function, etc. may include a mode in which the operation content of the driven element (actuator) of the automatic driving target is automatically determined according to a rule defined in advance. Further, the semiautomatic driving function, the fully automatic driving function, etc. may include a mode (so-called "autonomous driving function") in which the excavator 200 autonomously makes various determinations, and the operation content of the driven element (actuator) of the automatic driving target is determined autonomously according to the determination result.

[0026] [Configuration of Excavator] Next, in addition to FIG. 1, with reference to FIG. 2, the configuration of the excavator 200 according to the present embodiment will be described.

[0027] FIG. 2 is a block diagram schematically showing an example of the configuration of the excavator 200 according to the present embodiment. In FIG. 2, the mechanical power line is shown by a double line, the hydraulic line is shown by a thick solid line, the pilot line is shown by a broken line, and the electric drive / control line is shown by a thin solid line.

[0028] [Hydraulic Drive System] The hydraulic drive system of the excavator 200 according to the present embodiment includes hydraulic actuators such as travel hydraulic motors 1R, 1L, swing hydraulic motor 2M, boom cylinder 7, arm cylinder 8, and bucket cylinder 9 that hydraulically drive each of the driven elements such as the lower traveling body 1, boom 4, arm 5, and bucket 6. Further, the hydraulic drive system of the excavator 200 according to the present embodiment includes a pump motor 12, a main pump 14, and a control valve 17.

[0029] The motor 12 for the pump is an example of the motor in the present invention and is a power source for the hydraulic drive system. The motor 12 for the pump is, for example, an IPM (Interior Permanent Magnet) motor. The motor 12 for the pump is connected to a high-voltage power source including a battery module 19 via an inverter 18. The motor 12 for the pump is rotationally driven by three-phase AC power supplied from the battery module 19 via the inverter 18 to perform a power running operation, and drives the main pump 14 and the pilot pump 15. The drive control of the motor 12 for the pump may be executed by the inverter 18 under the control of a hydraulic excavator controller 30 described later.

[0030] The main pump 14 sucks hydraulic oil from the hydraulic oil tank T and discharges it into the high-pressure hydraulic line 16, thereby supplying hydraulic oil to the control valve 17 through the high-pressure hydraulic line 16. The main pump 14 is driven by the motor 12 for the pump. The main pump 14 is, for example, a variable displacement hydraulic pump, and under the control of a hydraulic excavator controller 30 described later, a regulator (not shown) controls the angle (tilt angle) of the swash plate. Thereby, the main pump 14 can adjust the stroke length of the piston and the discharge flow rate (discharge pressure).

[0031] Note that the main pump 14 may be driven by power from other power sources in addition to the pump motor 12. For example, during the lowering operation of the boom 4 or the closing operation of the arm 5, the energy of the hydraulic oil discharged from the boom cylinder 7 or the arm cylinder 8 to the hydraulic oil tank due to the self-weight of the boom 4 or the arm 5 may be regenerated to drive the main pump 14. Specifically, during the lowering operation of the boom 4 or the closing operation of the arm 5, the energy of the hydraulic oil discharged from the boom cylinder 7 or the arm cylinder 8 to the hydraulic oil tank due to the self-weight of the boom 4 or the arm 5 may be used to drive a hydraulic motor arranged coaxially with the rotating shaft of the main pump 14. Also, during the lowering operation of the boom 4 or the closing operation of the arm 5, the energy of the hydraulic oil discharged from the boom cylinder 7 or the arm cylinder 8 to the hydraulic oil tank due to the self-weight of the boom 4 or the arm 5 may be regenerated to cause a generator to generate electricity. Specifically, during the lowering operation of the boom 4 or the closing operation of the arm 5, the energy of the hydraulic oil discharged from the boom cylinder 7 or the arm cylinder 8 to the hydraulic oil tank due to the self-weight of the boom 4 or the arm 5 may be used to drive a hydraulic motor arranged coaxially with the generator, thereby causing the generator to generate electricity. In this case, the generated electric power of the generator may be supplied to the pump motor 12 or charged to the battery module 19.

[0032] The control valve 17 is a hydraulic control device that controls the hydraulic drive system in response to an operator's operation or an operation command corresponding to an automatic operation function. 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 the hydraulic oil supplied from the main pump 14 to 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 including a plurality of control valves (direction switching valves) that control the flow rate and flow direction of the hydraulic oil supplied from the main pump 14 to each of the hydraulic actuators. The hydraulic oil supplied from the main pump 14 and flowing through the control valve 17 and the hydraulic actuators is discharged from the control valve 17 to the hydraulic oil tank T.

[0033] <Electric drive system> The electric drive system of the excavator 200 according to this embodiment includes a pump motor 12, a sensor 12s, and an inverter 18. The electric drive system of the excavator 200 according to this embodiment also includes a battery module 19 having a high-voltage power source.

[0034] The sensor 12s includes a current sensor 12s1, a voltage sensor 12s2, and a rotation state sensor 12s3.

[0035] 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 provided, for example, in the power path between the pump motor 12 and the inverter 18. The detection signals corresponding to the currents of the three phases of the pump motor 12 detected by the current sensor 12s1 are directly taken into the inverter 18 through a communication line. Further, the detection signals may be taken into the excavator controller 30 through a communication line and input to the inverter 18 via the excavator controller 30.

[0036] The voltage sensor 12s2 detects the applied voltage of each of the three phases of the pump motor 12. The voltage sensor 12s2 is provided, for example, in the power path between the pump motor 12 and the inverter 18. The detection signals corresponding to the applied voltages of the three phases of the pump motor 12 detected by the voltage sensor 12s2 are directly taken into the inverter 18 through a communication line. Further, the detection signals may be taken into the excavator controller 30 through a communication line and input to the inverter 18 via the excavator controller 30.

[0037] The rotation state sensor 12s3 detects the rotation state (for example, rotation position (rotation angle), rotation speed, etc.) of the pump motor 12. The rotation state sensor 12s3 is, for example, a rotary encoder or a resolver.

[0038] The inverter 18 is an example of the motor drive device in the present invention, and controls the rotation of the pump motor 12 using the power supplied from the battery module 19. The inverter 18 includes, for example, a conversion circuit that converts DC power into three-phase AC power or converts three-phase AC power into DC power, a drive circuit that drives the conversion circuit by switching, 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.

[0039] The control circuit of the inverter 18 performs drive control of the pump motor 12 while grasping the operating state of the pump motor 12. For example, the control circuit of the inverter 18 grasps the operating state of the pump motor 12 based on the detection signal of the rotation state sensor 12s3. Further, the control circuit of the inverter 18 may grasp 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).

[0040] Note that at least one of the drive circuit and the control circuit of the inverter 18 may be provided outside the inverter 18. Other specific configurations of the inverter 18 will be described later.

[0041] The battery module 19 is configured to supply power from a high-voltage power source to the electronic components in the excavator 200. Specific configurations will be described later.

[0042] 〈Operating system〉 The operating system of the excavator 200 according to this embodiment includes a pilot pump 15, an operating device 26, and a pressure control valve 31.

[0043] The pilot pump 15 supplies pilot pressure to various hydraulic devices (e.g., the pressure control valve 31) mounted on the excavator 200 via the pilot line 25. As a result, the pressure control valve 31 can supply the control valve 17 with a pilot pressure corresponding to the operation content (e.g., the operation amount and operation direction) of the operation device 26 under the control of the excavator controller 30. Therefore, the excavator controller 30 and the pressure control valve 31 can realize the operation of the driven elements (hydraulic actuators) according to the operation content of the operator on the operation device 26. In addition, the pressure control valve 31 can supply the control valve 17 with a pilot pressure corresponding to the content of the remote operation specified by the remote operation signal under the control of the excavator 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.

[0044] The operation device 26 is provided within the reach of the operator at the operator's seat in the cabin 10 and is used for the operator to operate each driven element (i.e., the crawlers on the left and right 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 operation device 26 is used for the operator to operate the hydraulic actuators (e.g., the traveling hydraulic motors 1R, 1L, the slewing hydraulic motor 2M, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, etc.) and the electric actuators that drive each driven element. The operation device 26 is, for example, electric and outputs an electric signal (hereinafter, "operation signal") corresponding to the operation content by the operator. The operation signal output from the operation device 26 is taken into the excavator controller 30 via the signal line 28. Thereby, the excavator controller 30 can control the pressure control valve 31 and control the operation of the driven elements (actuators) of the excavator 200 according to the operation content of the operator and the operation commands corresponding to the automatic operation function.

[0045] The operating device 26 includes, for example, levers 26A to 26C. The lever 26A may be configured to be capable of receiving operations related to each of the arm 5 (arm cylinder 8) and the upper swing body 3 (swing operation) according to operations in the front-rear direction and the left-right direction. The lever 26B may be configured to be capable of receiving operations related to each of the boom 4 (boom cylinder 7) and the bucket 6 (bucket cylinder 9) according to operations in the front-rear direction and the left-right direction. The lever 26C may be configured to be capable of receiving an operation of the lower traveling body 1 (crawler).

[0046] When the control valve 17 is constituted by an electromagnetic pilot type control valve (direction change valve), the operation signal of the electric operating device 26 may be directly input to the control valve 17, and each hydraulic control valve may operate according to the operation content of the operating device 26. Further, the operating device 26 may be a hydraulic pilot type that outputs a pilot pressure according to the operation content. In this case, the pilot pressure according to the operation content is supplied to the control valve 17.

[0047] The pressure control valve 31 outputs a predetermined pilot pressure using the hydraulic oil supplied from the pilot pump 15 through the pilot line 25 under the control of the excavator 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.

[0048] 〈Power supply system〉 The power supply system of the excavator 200 is a group of components for supplying power to various electrical devices and includes a battery module 19.

[0049] The battery module 19 of the excavator 200 according to this embodiment is an example of the power control device in the present invention. The battery module 19 supplies power to each component within the excavator 200. The battery module 19 includes a battery having a high-voltage power source, and supplies power for rotationally driving the pump motor 12 using the high-voltage power source. Further, the battery module 19 has a battery controller that controls the components within the battery module 19. For example, the battery controller monitors the temperature status of the battery from the output result of a temperature sensor (not shown), and calculates the state of charge (SOC) of the battery. Then, the battery controller outputs the detection result of the temperature sensor and the SOC to the excavator controller 30. Thereby, the excavator controller 30 can cause the output device 50 (display device) inside the cabin 10 to display the temperature of the battery and the SOC of the battery. Further, the battery module 19 detects the rotational speed of the pump motor 12. The detected rotational speed may be displayed on the output device 50 (display device) inside the cabin 10. Other specific configurations of the battery module 19 will be described later.

[0050] Note that an example of the power supply device of the present invention is configured from the inverter 18 and the battery module 19.

[0051] <Control System> The control system of the excavator 200 according to this embodiment includes an excavator controller 30, an output device 50, and an input device 52.

[0052] The output device 50 is provided inside the cab 10 and outputs various types of information to the operator under the control of the excavator 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 is installed, for example, in a location that is easily visible to the operator inside the cab 10 and may display various information images under the control of the excavator controller 30. The display device is, for example, a liquid crystal display or an organic EL (Electroluminescence) display. Further, the output device 50 includes, for example, a sound output device that outputs information to the operator in an auditory manner. The sound output device is, for example, a buzzer or a speaker, etc.

[0053] The input device 52 is provided inside the cab 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. Further, the input device 52 may also include, for example, a voice input device that receives voice inputs from the operator or a gesture input device that receives gesture inputs from the operator. The voice input device includes, for example, a microphone that acquires the voice of the operator inside the cab 10. Also, the gesture input device includes, for example, an in-cab camera capable of imaging the state of the gestures of the operator inside the cab 10. The signal corresponding to the input from the operator received by the input device 52 is taken into the excavator controller 30.

[0054] Each function of the excavator controller 30 may be realized by arbitrary hardware, or an arbitrary combination of hardware and software, etc. For example, the excavator controller 30 may be mainly configured around a computer including a processor such as a CPU (Central Processing Unit), a memory device (main memory device) such as a RAM (Random Access Memory), a non-volatile auxiliary storage device such as a ROM (Read Only Memory), and an interface device for input / output with the outside, etc.

[0055] The excavator controller 30 is an example of the control device in the present invention and controls the drive of the excavator 200. The excavator controller 30 outputs a control command to the pressure control valve 31, for example, according to an operation signal input from the operation device 26, and causes the pressure control valve 31 to output a pilot pressure corresponding to the operation content of the operation device 26. Thereby, the excavator controller 30 can realize the operation of the driven element (hydraulic actuator) of the excavator 200 corresponding to the operation content of the electric operation device 26.

[0056] When the excavator 200 is remotely operated, the excavator controller 30 may perform control related to remote operation, for example. Specifically, the excavator controller 30 may output a control command to the pressure control valve 31 and cause the pressure control valve 31 to output a pilot pressure corresponding to the content of the remote operation. Thereby, the excavator controller 30 can realize the operation of the excavator 200 (driven element) corresponding to the content of the remote operation.

[0057] The excavator controller 30 may also perform control related to the automatic driving function, for example. Specifically, the excavator controller 30 may output a control command to the pressure control valve 31 and cause the pilot pressure corresponding to the operation command corresponding to the automatic driving function to act on the control valve 17 from the pressure control valve 31. Thereby, the excavator controller 30 can realize the operation of the driven element (hydraulic actuator) of the excavator 200 corresponding to the automatic driving function.

[0058] The excavator controller 30 may integrally control the operation of the entire excavator 200 (various devices mounted on the excavator 200).

[0059] The excavator controller 30 performs drive control of the electric drive system based on various input information (for example, a control command including an operation signal of the operation device 26).

[0060] Further, the excavator controller 30 may perform switching control between the discharge state and the charge state of the battery module 19, for example, based on the operation state of the operating device 26. Further, the excavator controller 30 may perform switching control between the discharge state and the charge state of the battery module 19, for example, when the excavator 200 is remotely operated, based on the content of the remote operation. Further, the excavator controller 30 may perform switching control between the discharge state and the charge state of the battery module 19, for example, when the automatic operation function of the excavator 200 is effective, based on an operation command corresponding to the automatic operation function. Other specific configurations of the excavator controller 30 will be described later.

[0061] Further, the excavator 200 in the present embodiment includes a key cylinder 61 and a backup start switch 62.

[0062] The key cylinder 61 is an example of a starting device in the present invention. The key cylinder 61 is operated when starting the excavator 200. For example, it is provided in the cab 10, and when the operator of the excavator 200 inserts and turns the key, a start signal is output to the excavator controller 30. Note that a smart key may be used as the starting device for starting the excavator 200. When a smart key is used as the starting device, a start signal is output to the excavator controller 30 when the operator of the excavator 200 presses the switch (button) of the smart key.

[0063] The backup start switch 62 is an example of a startup standby device in the present invention. The backup start switch 62 is configured to be operable from the outside and is operated to start the excavator 200 when the excavator controller 30, the key cylinder 61, or the CAN bus 70 (see FIG. 6) connecting these fails. For example, it is provided in the cab 10 and outputs a backup start signal to the battery module 19 and the inverter 18 when operated by the operator of the excavator 200. Note that the backup start switch 62 may be a push-button type that can be pressed or a tiltable switch. Also, the backup start switch 62 is preferably not operated during normal times. Therefore, the backup start switch 62 may be provided in a place where the operator of the excavator 200 cannot normally operate, or may be configured with a door that can be locked with a key inside the cab 10.

[0064] <Configuration related to starting of the excavator 200> The configuration related to starting of the excavator 200 will be described below.

[0065] FIG. 3 is a block diagram showing the configuration related to starting of the excavator 200 of the excavator controller 30 shown in FIG. 2.

[0066] As shown in FIG. 3, the excavator controller 30 in the present embodiment includes a startup signal reception unit 301, a power supply instruction unit 302, a motor drive instruction unit 303, a status notification unit 304, and a communication unit 305.

[0067] The startup signal reception unit 301 receives the startup signal output from the key cylinder 61 when the operator of the excavator 200 turns the key inserted into the key cylinder 61.

[0068] When the startup signal output from the key cylinder 61 is received by the startup signal reception unit 301, the power supply instruction unit 302 instructs the battery module 19 to supply power to the inverter 18 by connecting the high-voltage power supply to the inverter 18.

[0069] When the motor drive instruction unit 303 receives a completion signal indicating that the high-voltage power supply is connected to the inverter 18 from the battery module 19, it instructs the inverter 18 to drive the pump motor 12.

[0070] The status notification unit 304 outputs a response signal to the monitoring signals transmitted from the battery module 19 and the inverter 18. Thereby, the status notification unit 304 notifies the battery module 19 and the inverter 18 of the status of the excavator controller 30.

[0071] The communication unit 305 communicates with the key cylinder 61, the battery module 19, and the inverter 18 via a CAN (Controller Area Network) bus 70 (see FIG. 6), which is an example of a communication network.

[0072] FIG. 4 is a block diagram showing the configuration related to the startup of the battery module 19 of the excavator 200 shown in FIG. 2.

[0073] As shown in FIG. 4, the battery module 19 in the present embodiment includes a high-voltage power supply 191, an instruction transceiver 192, a power supply unit 193, a status monitoring unit 194, a backup start signal receiving unit 195, and a communication unit 196.

[0074] The high-voltage power supply 191 is connected to the inverter 18 when driving the pump motor 12. For example, it may be a lithium-ion battery having a relatively high output voltage (for example, several hundred volts). The high-voltage power supply 191 is charged (electrically stored) by being connected to an external power supply with a charging cable.

[0075] The instruction transceiver 192 receives an instruction from the excavator controller 30 to supply power to the inverter 18 by connecting the high-voltage power supply 191 to the inverter 18, and transmits a completion signal indicating that the high-voltage power supply 191 has been connected to the inverter 18 to the excavator controller 30.

[0076] When the power supply unit 193 receives an instruction from the excavator controller 30 to supply power to the inverter 18 by connecting the high-voltage power supply 191 to the inverter 18, it supplies power to the inverter 18 by connecting the high-voltage power supply 191 to the inverter 18.

[0077] The state monitoring unit 194 monitors the states of the key cylinder 61 and the excavator controller 30 via the CAN bus 70 (see FIG. 6). Specifically, when receiving a failure signal output when the key cylinder 61 fails, it recognizes that the key cylinder 61 has failed. Also, it transmits a monitoring signal to the excavator controller 30 and recognizes the state of the excavator controller 30 based on whether a response signal to the monitoring signal is transmitted from the excavator controller 30. Further, it can also recognize whether a failure such as a disconnection has occurred in the CAN bus 70 based on the resistance value of the CAN bus 70.

[0078] The backup start signal receiving unit 195 is connected to the backup start switch 62 via a network different from the CAN bus (see FIG. 6), such as a general cable, and receives the backup start signal output from the backup start switch 62. When the backup start signal receiving unit 195 receives the backup start signal output from the backup start switch 62 in a state where the state monitoring unit 194 recognizes that at least one of the key cylinder 61, the excavator controller 30, and the CAN bus 70 has failed, it outputs an instruction to supply power to the inverter 18 by connecting the high-voltage power supply to the inverter 18 to the power supply unit 193.

[0079] The communication unit 196 communicates with the key cylinder 61, the excavator controller 30, and the inverter 18 via the CAN bus 70 (see FIG. 6).

[0080] FIG. 5 is a block diagram showing the configuration related to the start-up of the excavator 200 of the inverter 18 shown in FIG. 2.

[0081] As shown in FIG. 5, the inverter 18 in the present embodiment includes an instruction receiving unit 181, a power receiving unit 182, a motor driving unit 183, a state monitoring unit 184, a backup start signal receiving unit 185, and a communication unit 186.

[0082] The instruction receiving unit 181 receives an instruction to drive the pump motor 12 from the excavator controller 30.

[0083] The power receiving unit 182 receives power for driving the pump motor 12 by being connected to the high-voltage power supply 191 of the battery module 19.

[0084] The motor driving unit 183 drives the pump motor 12 using the power received by the power receiving unit 182.

[0085] The state monitoring unit 184 monitors the states of the key cylinder 61 and the excavator controller 30 via the CAN bus 70 (see FIG. 6). Specifically, it recognizes that the key cylinder 61 has failed by receiving a failure signal output when the key cylinder 61 fails. Also, it transmits a monitoring signal to the excavator controller 30 and recognizes the state of the excavator controller 30 based on whether a response signal to the monitoring signal is transmitted from the excavator controller 30. Further, it can also recognize whether a failure such as a disconnection has occurred in the CAN bus 70 based on the resistance value of the CAN bus 70.

[0086] The backup start signal receiving unit 185 is connected to the backup start switch 62 via a network different from the CAN bus (see FIG. 6), such as a general cable, and receives the backup start signal output from the backup start switch 62. When the backup start signal receiving unit 185 receives the backup start signal output from the backup start switch 62 in a state where the state monitoring unit 184 recognizes that at least one of the key cylinder 61, the excavator controller 30, and the CAN bus 70 has failed, it outputs an instruction to the motor drive unit 183 to drive the pump motor 12 using the power received by the power receiving unit 182.

[0087] The communication unit 186 communicates with the key cylinder 61, the excavator controller 30, and the battery module 19 via the CAN bus 70 (see FIG. 6).

[0088] FIG. 6 is a diagram showing the connection state of the key cylinder 61, the excavator controller 30, the battery module 19, and the inverter 18 shown in FIG. 2.

[0089] As shown in FIG. 6, the key cylinder 61, the excavator controller 30, the battery module 19, and the inverter 18 shown in FIG. 2 are connected to each other via the CAN bus 70. Therefore, the battery module 19 and the inverter 18 can each monitor the states of the key cylinder 61 and the excavator controller 30. For example, in the key cylinder 61, the battery module 19 and the inverter 18 can each receive, via the CAN bus 70, a failure signal output when the key cylinder 61 fails, thereby recognizing that the key cylinder 61 has failed. Further, the battery module 19 and the inverter 18 each transmit a monitoring signal to the excavator controller 30 via the CAN bus 70, and based on whether a response signal to the monitoring signal is transmitted from the excavator controller 30 via the CAN bus 70, the state of the excavator controller 30 can be recognized. Also, each of the battery module 19 and the inverter 18 can recognize whether a failure such as a disconnection has occurred in the CAN bus 70 based on the resistance value of the CAN bus 70.

[0090] 〈Operation at startup of the excavator 200〉 The operation at startup of the excavator 200 will be described below.

[0091] First, the operation during normal startup will be described.

[0092] FIG. 7 is a flowchart for explaining the operation during normal startup of the excavator 200 according to the present embodiment.

[0093] When an operator of the excavator 200 inserts and turns a key into the key cylinder 61, and a startup signal for starting the excavator 200 is output from the key cylinder 61, the startup signal receiving unit 301 of the excavator controller 30 receives the startup signal output from the key cylinder 61 (step ST1).

[0094] When the start signal output from the key cylinder 61 is received by the start signal receiving unit 301 (YES in step ST1), the power supply instruction unit 302 of the excavator controller 30 transmits an instruction to supply power to the inverter 18 by connecting a high-voltage power supply to the inverter 18 to the battery module 19 via the communication unit 305 (step ST2).

[0095] The instruction transmitted from the power supply instruction unit 302 is transmitted to the battery module 19 via the CAN bus 70, and received by the instruction transmission / reception unit 192 via the communication unit 196 of the battery module 19 (step ST3).

[0096] When the instruction transmitted from the power supply instruction unit 302 is received by the instruction transmission / reception unit 192, the power supply unit 193 of the battery module 19 supplies power to the inverter 18 by connecting the high-voltage power supply 191 to the inverter 18 (step ST4). As a result, the power receiving unit 182 of the inverter 18 receives power for driving the pump motor 12.

[0097] When the battery module 19 connects the high-voltage power supply 191 to the inverter 18, the instruction transmission / reception unit 192 transmits a completion signal indicating that the high-voltage power supply has been connected to the inverter 18 to the excavator controller 30 via the communication unit 196 (step ST5).

[0098] The completion signal transmitted from the instruction transmission / reception unit 192 is transmitted to the excavator controller 30 via the CAN bus 70, and received by the motor drive instruction unit 303 via the communication unit 305 of the excavator controller 30 (step ST6).

[0099] When the motor drive instruction unit 303 receives a completion signal indicating that the high-voltage power supply 191 has been connected to the inverter 18 from the battery module 19, it transmits an instruction to drive the pump motor 12 to the inverter 18 via the communication unit 305 (step ST7).

[0100] The instruction transmitted from the motor drive instruction unit 303 is transmitted to the inverter 18 via the CAN bus 70, and is received by the instruction receiving unit 181 via the communication unit 186 of the inverter 18 (step ST8).

[0101] When the instruction transmitted from the motor drive instruction unit 303 is received by the instruction receiving unit 181, the motor drive unit 183 drives the pump motor 12 using the power received by the power receiving unit 182 (step ST9).

[0102] As described above, in the excavator 200 according to the present embodiment, when the operator of the excavator 200 inserts and turns the key into the key cylinder 61, a start signal for starting the excavator 200 is output and received by the excavator controller 30. Then, the excavator controller 30 instructs the battery module 19 to connect the high-voltage power supply to the inverter 18, and then instructs the inverter 18 to drive the pump motor 12 using the connected high-voltage power supply. The excavator 200 starts when the pump motor 12 is driven.

[0103] In this way, triggered by the output of the start signal from the key cylinder 61, the excavator 200 starts when the excavator controller 30 outputs instructions to the battery module 19 and the inverter 18. Therefore, if a failure occurs in the key cylinder 61 or the excavator controller 30, the excavator 200 cannot be started. Also, if a failure such as a disconnection occurs in the CAN bus 70 connecting these, the excavator 200 cannot be started. Therefore, it is preferable to enable the excavator 200 to be started even when a failure occurs in the key cylinder 61, the excavator controller 30, or the CAN bus 70.

[0104] Next, the operation in the event of a failure of the key cylinder 61, the excavator controller 30, or the CAN bus 70 will be described. First, the operation of the battery module 19 will be described.

[0105] FIG. 8 is a flowchart for explaining the operation of the battery module 19 when the key cylinder 61, the excavator controller 30, or the CAN bus 70 of the excavator 200 according to the present embodiment fails.

[0106] When the key cylinder 61, the excavator controller 30, or the CAN bus 70 of the excavator 200 fails and the excavator 200 does not start even when the operator of the excavator 200 inserts and turns the key in the key cylinder 61, when the operator of the excavator 200 operates the backup start switch 62, a backup start signal is output from the backup start switch 62. Here, when the excavator 200 does not start even when the operator of the excavator 200 inserts and turns the key in the key cylinder 61, the operator of the excavator 200 may be prompted to operate the backup start switch 62. For example, the fact that the backup start switch 62 is to be operated may be displayed and output to the output device 50. In particular, when the backup start switch 62 is provided in a place where the operator of the excavator 200 cannot normally operate it, or when it is configured with a door that can be locked with a key inside the cabin 10, the operator of the excavator 200 may not know where the backup start switch 62 is, and may not even recognize the existence of the backup start switch 62 itself. Therefore, when the excavator 200 does not start even when the operator of the excavator 200 inserts and turns the key in the key cylinder 61, it is preferable to prompt the operator of the excavator 200 to operate the backup start switch 62. In that case, the output device 50 may be connected to the key cylinder 61 and the excavator controller 30 via the CAN bus 70, and the states of the key cylinder 61, the excavator controller 30, and the CAN bus 70 may be monitored by the output device 50 in the same manner as the battery module 19 and the inverter 18.

[0107] The backup start signal output from the backup start switch 62 is received by the backup start signal receiving unit 195 of the battery module 19 via a cable wiring different from the CAN bus 70 (step ST11).

[0108] Here, in the battery module 19, the state monitoring unit 194 monitors the states of the key cylinder 61 and the excavator controller 30. Specifically, when receiving a failure signal output when the key cylinder 61 fails, it recognizes that the key cylinder 61 has failed. Also, it transmits a monitoring signal to the excavator controller 30, and when a response signal to the monitoring signal is not transmitted from the excavator controller 30, it recognizes that the excavator controller 30 has failed. Further, the battery module 19 monitors whether a failure such as a disconnection has occurred in the CAN bus 70 based on the resistance value of the CAN bus 70, and when the resistance value of the CAN bus 70 is an abnormal value significantly different from a predetermined resistance value, it recognizes that a failure such as a disconnection has occurred in the CAN bus 70.

[0109] Therefore, when the battery module 19 receives the backup start signal output from the backup start switch 62 (YES in step ST11), it can determine whether at least any one of the key cylinder 61, the excavator controller 30, and the CAN bus 70 has failed (step ST12).

[0110] When at least one of the key cylinder 61, the excavator controller 30, and the CAN bus 70 malfunctions (YES in step ST12), the battery module 19 determines whether the pump motor 12 is being driven (step ST13). Since the battery module 19 detects the rotational speed of the pump motor 12 as described above, it can determine whether the pump motor 12 is being driven. Also, the battery module 19 can recognize the operating status of the key cylinder 61 via the CAN bus 70. Therefore, when only the excavator controller 30 among the key cylinder 61, the excavator controller 30, and the CAN bus 70 malfunctions, it is possible to check the operating status of the key cylinder 61 and check whether the key cylinder 61 was operated before the backup start switch 62 was operated. That is, when the backup start switch 62 is operated, although the operator of the excavator 200 operates the key cylinder 61 to start the excavator 200, the excavator 200 does not start because the excavator controller 30 malfunctions, and thus it is possible to recognize that the backup start switch 62 was operated.

[0111] When the pump motor 12 is not being driven (NO in step ST13), the power supply unit 193 of the battery module 19 supplies power to the inverter 18 by connecting the high-voltage power source 191 to the inverter 18 (step ST14).

[0112] On the other hand, when it is determined in step ST12 that none of the key cylinder 61, the excavator controller 30, and the CAN bus 70 malfunctions (NO in step ST12), even if the backup start switch 62 is operated and the backup start signal is received by the battery module 19, power supply to the inverter 18 based on the operation of the backup start switch 62 is not performed (step ST15). This is to invalidate the operation of the backup start switch 62 if it is operated without reason when none of the key cylinder 61, the excavator controller 30, and the CAN bus 70 malfunctions.

[0113] Also, when it is determined in step ST13 that the pump motor 12 is being driven (YES in step ST13), even if the backup start switch 62 is operated and the backup start signal is received by the battery module 19, power supply to the inverter 18 based on the operation of the backup start switch 62 is not performed (step ST15). This is because when the pump motor 12 is being driven, there is no need to deliberately supply power to the inverter 18 to drive the pump motor 12. Thus, when the backup start switch 62 is operated while the pump motor 12 is rotating, the battery module 19 does not supply power to the pump motor 12 based on the operation of the backup start switch 62. This can avoid unnecessary control from being performed.

[0114] Also, as described above, when the battery module 19 can confirm whether the key cylinder 61 has been operated before the backup start switch 62 is operated, the power supply unit 193 may supply power to the inverter 18 by connecting the high-voltage power supply 191 to the inverter 18 only when the key cylinder 61 has been operated before the backup start switch 62 is operated. This can avoid power being supplied to the inverter 18 when the backup start switch 62 is operated or is inadvertently operated even though none of the key cylinder 61, the excavator controller 30, and the CAN bus 70 are faulty.

[0115] Next, the operation of the inverter 18 in the event of a failure of the key cylinder 61, the excavator controller 30, or the CAN bus 70 will be described.

[0116] FIG. 9 is a flowchart for explaining the operation of the inverter 18 in the event of a failure of the key cylinder 61, the excavator controller 30, or the CAN bus 70 of the excavator 200 according to the present embodiment.

[0117] When the operator of the excavator 200 operates the backup start switch 62 and a backup start signal is output from the backup start switch 62, the backup start signal is also received at the backup start signal receiving unit 185 of the inverter 18 via a cable wiring different from the CAN bus 70 (step ST21). Also, in the inverter 18, the state monitoring unit 184 monitors the states of the key cylinder 61, the excavator controller 30, and the CAN bus 70.

[0118] Therefore, when the inverter 18 receives the backup start signal output from the backup start switch 62 (YES in step ST21), it can determine whether at least any one of the key cylinder 61, the excavator controller 30, and the CAN bus 70 has failed (step ST22).

[0119] When at least one of the key cylinder 61, the excavator controller 30, and the CAN bus 70 malfunctions (YES in step ST22), the inverter 18 determines whether the pump motor 12 is being driven (step ST23). As described above, the inverter 18 grasps the operating state of the pump motor 12 based on the detection signal of the rotation state sensor 12s3, so it can determine whether the pump motor 12 is being driven. Also, the inverter 18 can recognize the operation status of the key cylinder 61 via the CAN bus 70. Therefore, when only the excavator controller 30 among the key cylinder 61, the excavator controller 30, and the CAN bus 70 malfunctions, it is possible to confirm the operation status of the key cylinder 61 and whether the key cylinder 61 was operated before the backup start switch 62 was operated. That is, when the backup start switch 62 is operated, although the operator of the excavator 200 tries to start the excavator 200 by operating the key cylinder 61, the excavator 200 does not start because the excavator controller 30 malfunctions, so it is possible to recognize that the backup start switch 62 has been operated.

[0120] When the pump motor 12 is not being driven (NO in step ST23), the inverter 18 determines whether the inverter 18 is connected to the high-voltage power supply 191 of the battery module 19 and receiving power at the power receiving unit 182 (step ST24).

[0121] When the inverter 18 is connected to the high-voltage power supply 191 of the battery module 19 (YES in step ST24), the motor drive unit 183 drives the pump motor 12 using the power received at the power receiving unit 182 (step ST25). At this time, the motor drive unit 183 may drive the pump motor 12 with power such that the pump motor 12 rotates at the minimum number of rotations required for the excavator 200 to move to the standby position.

[0122] On the other hand, if it is determined in step ST12 that none of the key cylinder 61, the excavator controller 30, and the CAN bus 70 has failed (NO in step ST22), even if the backup start switch 62 is operated and the backup start signal is received by the battery module 19, the pump motor 12 is not driven based on the operation of the backup start switch 62 (step ST26). This is to invalidate the operation of the backup start switch 62 if it is operated arbitrarily even though none of the key cylinder 61, the excavator controller 30, and the CAN bus 70 has failed.

[0123] Also, even if it is determined in step ST23 that the pump motor 12 is being driven (YES in step ST23), and the backup start switch 62 is operated and the backup start signal is received by the battery module 19, the pump motor 12 is not driven based on the operation of the backup start switch 62 (step ST26). This is because when the pump motor 12 is being driven, there is no need to perform control to drive the pump motor 12 intentionally.

[0124] Also, even if in step ST24 it is determined that the inverter 18 is not connected to the high-voltage power supply 191 of the battery module 19 (NO in step ST24), and the backup start switch 62 is operated and the backup start signal is received by the battery module 19, the pump motor 12 is not driven based on the operation of the backup start switch 62 (step ST26).

[0125] Also, as described above, when the inverter 18 can confirm whether the key cylinder 61 has been operated before the backup start switch 62 is operated, the motor drive unit 183 may drive the pump motor 12 using the power received by the power receiving unit 182 only when the key cylinder 61 has been operated before the backup start switch 62 is operated. This can prevent the pump motor 12 from being driven when the backup start switch 62 is operated or unintentionally operated even though none of the key cylinder 61, the excavator controller 30, and the CAN bus 70 are faulty.

[0126] As described above, the excavator 200 according to the present embodiment includes a key cylinder 61 for starting the excavator 200, a backup start switch 62 for starting the excavator 200 by means different from the key cylinder 61, and an excavator controller 30 for starting the excavator 200 when an operation on the key cylinder 61 is performed. When the excavator 200 is started by the backup start switch 62, the excavator 200 starts without passing through the excavator controller 30, and the functions of the excavator 200 are restricted more than when the excavator 200 is started by the key cylinder 61. Thereby, even when a failure occurs in the excavator controller 30, the excavator 200 can be moved to perform minimum movement such as moving to a standby position. Further, it includes a pump motor 12 that is rotationally driven by supplied power, a battery module 19 and an inverter 18 that supply power to the pump motor 12, and a CAN bus 70 that interconnects the battery module 19, the inverter 18, the key cylinder 61, and the excavator controller 30. When an operation on the key cylinder 61 is performed, the excavator controller 30 instructs the battery module 19 and the inverter 18 to supply power to the pump motor 12. Then, the battery module 19 and the inverter 18 supply power to the pump motor 12 according to an instruction from the excavator controller 30 when no failure has occurred in any of the key cylinder 61, the excavator controller 30, and the CAN bus 70, and supply power to the pump motor 12 based on an operation on the backup start switch 62 when a failure has occurred in at least one of the key cylinder 61, the excavator controller 30, and the CAN bus 70. Thereby, even when a failure occurs other than the excavator controller 30, the excavator 200 can be moved by the backup start switch 62.

[0127] Also, if the pump motor 12 is driven with power such that it rotates at the minimum number of revolutions required for the excavator 200 to move to the standby position, in the event of a failure in the key cylinder 61, the excavator controller 30, or the CAN bus 70, the startup of the excavator 200 can be kept at the level of an emergency measure at most, and it is possible to avoid the excavator 200 starting up and performing unnecessary work.

[0128] Also, the battery module 19 and the inverter 18 respectively monitor whether there is a failure in the key cylinder 61 and the excavator controller 30 via the CAN bus 70. Thereby, it is possible to reliably monitor whether there is a failure in the key cylinder 61, the excavator controller 30, and the CAN bus 70.

[0129] In the present embodiment, the battery module 19 and the inverter 18 respectively monitor whether there is a failure in the key cylinder 61 and the excavator controller 30 via the CAN bus 70. However, only the battery module 19 may monitor whether there is a failure in the key cylinder 61 and the excavator controller 30 via the CAN bus 70. By adopting such a configuration, the configuration of the inverter 18 can be simplified to an inexpensive configuration. In that case, the inverter 18 may not perform the processing shown in FIG. 9 and may simply be configured to drive the pump motor 12 only when it is connected to the high-voltage power supply 191 by the battery module 19.

Explanation of Reference Numerals

[0130] 1 Lower Travel Body 1L, 1R Travel Hydraulic Motor 2 Swing Mechanism 2M Swing Hydraulic Motor 3 Upper Swing Structure 4 Boom 5 Arm 6 Bucket 7 Boom Cylinder 8 Arm Cylinder 9 Bucket Cylinder 10 Cabin 12 Pump motor 12s1 Current sensor 12s2 Voltage sensor 12s3 Rotation state sensor 14 Main pump 15 Pilot pump 16 High-pressure hydraulic line 17 Control valve 18 Inverter 19 Battery module 26 Operating device 26A~26C Lever 28 Signal line 30 Excavator controller 31 Pressure control valve 50 Output device 52 Input device 61 Key cylinder 62 Backup start switch 70 CAN bus 181 Instruction receiving section 182 Power receiving section 183 Motor drive section 184,194 State monitoring section 185,195 Backup start signal receiving section 186,196,305 Communication section 191 High-voltage power source 192 Instruction transmission / reception section 193 Power supply section 200 Excavator 301 Start signal receiving section 302 Power supply instruction section 303 Motor drive instruction section 304 State notification section T Working oil tank

Claims

1. An excavator, comprising: a starting device for starting the excavator; a backup starting device for starting the excavator by means different from the starting device; a control device for starting the excavator when an operation on the starting device is performed, wherein when the excavator is started by the backup starting device, the excavator starts without passing through the control device, and the function of the excavator is restricted compared to the case where the excavator is started by the starting device.

2. an electric motor rotationally driven by supplied power; a power supply device for supplying power to the electric motor; a communication network for interconnecting the power supply device, the starting device, and the control device, wherein the control device instructs the power supply device to supply power to the electric motor when an operation on the starting device is performed, and the power supply device supplies power to the electric motor according to an instruction from the control device when no failure has occurred in any of the starting device, the control device, and the communication network, and supplies power to the electric motor based on an operation on the backup starting device when a failure has occurred in at least one of the starting device, the control device, and the communication network. The excavator according to claim 1.

3. The excavator according to claim 2, wherein when the power supply device supplies power to the electric motor based on an operation on the backup starting device, the power supply device supplies power to the electric motor such that the rotation of the electric motor becomes a predetermined rotational speed lower than that when the excavator is started by the starting device.

4. The excavator according to claim 2, wherein when an operation on the backup starting device is performed while the electric motor is rotating, the power supply device does not supply power to the electric motor based on the operation on the backup starting device.

5. The power supply device comprises a power control device for supplying power for rotationally driving the electric motor using a high-voltage power source; and an electric motor driving device for rotationally controlling the electric motor using the power supplied from the power control device, wherein the power control device and the electric motor driving device each monitor whether a failure has occurred in the starting device and the control device via the communication network. The excavator according to claim 2.

6. The power supply device comprises a power control device for supplying power for rotationally driving the electric motor using a high-voltage power source; It has a motor drive device that rotationally controls the motor using the power supplied from the power control device. The excavator according to claim 2, wherein the power control device monitors whether or not a failure has occurred in the starting device and the control device via the communication network.

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