Electric powered machinery

Abstract

To notify an operator of information on the power supply status.SOLUTION: A work machine body 10 can be connected to a power supply unit S. An electric motor 35 is mounted on the work machine body 10 and driven by electric power supplied from the power supply unit S. A hydraulic pump 21 is mounted on the work machine body 10 and driven by the electric motor 35. A hydraulic actuator 23 is mounted on the work machine body 10 and driven by pressure oil discharged by the hydraulic pump 21. An electric motor controller 45 detects the power supply state from the power supply unit S to the electric motor 35. A notification unit 60 outputs information regarding the power supply state detected by the electric motor controller 45.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electric working machine having an electric motor. [Background technology]

[0002] For example, a conventional electric working machine is described in Patent Document 1. In the invention described in this document, a power supply unit and a working machine main body are connected via a power supply line (see FIG. 1 in the document). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-184783 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an electric working machine, for example, a situation may occur in which the power supply state from the power source to the electric motor is not appropriate due to incorrect connection, disconnection, or poor contact of electric wires or connection terminals. In the invention described in the document, even if the power supply state is not appropriate, information regarding the power supply state is not notified to the operator. Therefore, there is a demand for an electric working machine that can notify the operator of the power supply state.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide an electric working machine that is capable of notifying an operator of information relating to the power supply state. [Means for solving the problem]

[0006] The electric work machine comprises a work machine body, an electric motor, a hydraulic pump, a hydraulic actuator, an electric motor controller, and a notification unit. The work machine body is connectable to a power supply unit. The electric motor is mounted on the work machine body and driven by electric power supplied from the power supply unit. The hydraulic pump is mounted on the work machine body and driven by the electric motor. The hydraulic actuator is mounted on the work machine body and driven by pressure oil discharged by the hydraulic pump. The electric motor controller detects the state of power supply from the power supply unit to the electric motor. The notification unit outputs information related to the power supply state detected by the electric motor controller. Effect of the Invention

[0007] With the above configuration, information regarding the power supply state can be notified to an operator. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of the electric working machine 1. [Diagram 2] FIG. 2 is a block diagram of the electric working machine 1 shown in FIG. [Diagram 3] 3 is a flowchart showing the process of an electric motor controller 45 shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The electric working machine 1 will be described with reference to Figs. 1 to 3.

[0010] As shown in FIG. 1, the electric work machine 1 is a work machine that operates with power supplied from a power source unit S. The electric work machine 1 is a machine that performs work, for example, an electric construction machine that performs construction work, and may be, for example, an electric shovel or an electric crane. In the following, a case where the electric work machine 1 is an electric shovel (more specifically, an electric hydraulic shovel) will be described. The electric work machine 1 can be connected to the power source unit S via a power supply line C. The power source unit S is a power source for the electric work machine 1. The power source unit S is provided outside the electric work machine 1 (is an external power source). The power source unit S is immobile or mobile (portable). The power source unit S may be a power source facility fixed to a building (for example, a factory) in which the electric work machine 1 is used. The power source unit S may be a portable power source that is connected to the electric work machine 1 when the electric work machine 1 is moved, and may be, for example, an engine generator, and specifically, may be a diesel generator. The power supply line C is an electric wire (cable) that transmits power from the power source unit S to the electric work machine 1. The electric work machine 1 includes a work machine main body 10, a hydraulic circuit section 20 shown in FIG. 2, an electric motor device 30, a work machine controller 51, a work machine operation section 53, an electric motor operation section 55, and a notification section 60.

[0011] As shown in FIG. 1, the work machine body 10 includes a lower traveling body 11, an upper rotating body 13, and an attachment 15. The lower traveling body 11 allows the work machine body 10 to travel. The lower traveling body 11 includes, for example, a crawler. The upper rotating body 13 is mounted on the lower traveling body 11 so as to be rotatable. The upper rotating body 13 includes a cab 13a and a counterweight 13b. The cab 13a is a portion where an operator can operate the electric work machine 1. The electric work machine 1 may be operated by an operator in the cab 13a, may be remotely operated from outside the electric work machine 1, or may be automatically operated by a controller that performs automatic operation (for example, a work machine controller 51 (see FIG. 2)). The counterweight 13b is a weight for balancing the work machine body 10 in the front-rear direction.

[0012] The attachment 15 is a part that performs work, and includes, for example, a boom 15a, an arm 15b, and a tip attachment 15c. The boom 15a is attached to the upper rotating body 13 so that it can be raised and lowered (rotated vertically). The arm 15b is attached rotatably relative to the boom 15a. The tip attachment 15c is provided at the tip of the attachment 15, and is rotatably attached to the arm 15b. The tip attachment 15c may be, for example, a device for clamping objects (such as a grapple), a device for crushing or excavating, or a bucket for scooping up soil and sand.

[0013] The hydraulic circuit section 20 (see FIG. 2) operates the work machine body 10 by pressure oil. The hydraulic circuit section 20 is mounted on the work machine body 10. As shown in FIG. 2, the hydraulic circuit section 20 includes a hydraulic pump 21, a hydraulic actuator 23, and a hydraulic control valve 25.

[0014] The hydraulic pump 21 is driven by an electric motor 35 (described later) to discharge oil (pressurized oil). The discharge flow rate of the hydraulic pump 21 may be variable or fixed.

[0015] The hydraulic actuator 23 operates the work machine body 10 (see FIG. 1). The hydraulic actuator 23 is driven by pressure oil discharged by the hydraulic pump 21. As shown in FIG. 1, the hydraulic actuator 23 includes a travel motor 23a, a swing motor 23b, a boom cylinder 23c, an arm cylinder 23d, and a tip attachment cylinder 23e. The travel motor 23a drives the work machine body 10 to travel, drives the lower traveling body 11 to travel, and drives, for example, a crawler. The travel motor 23a is a hydraulic motor (as is the swing motor 23b). The swing motor 23b drives the upper rotating body 13 to swing relative to the lower traveling body 11. The boom cylinder 23c drives the boom 15a to rise and fall relative to the upper rotating body 13. The boom cylinder 23c is a telescopic cylinder (hydraulic cylinder) (as are the arm cylinder 23d and the tip attachment cylinder 23e). The arm cylinder 23d rotates the arm 15b relative to the boom 15a. The tip attachment cylinder 23e rotates the tip attachment 15c relative to the arm 15b. If the tip attachment 15c itself is drivable (for example, if it is capable of clamping and releasing an object), a hydraulic cylinder or hydraulic motor for driving the tip attachment 15c may be provided.

[0016] 2, the hydraulic control valve 25 controls the operation of the hydraulic actuator 23 by controlling the pressure oil supplied from the hydraulic pump 21 to the hydraulic actuator 23. The hydraulic control valve 25 is provided between the hydraulic pump 21 and the hydraulic actuator 23 (in the oil passage). The hydraulic control valve 25 is a directional control valve that controls the direction of the oil flow in the oil passage. The hydraulic control valve 25 controls the flow rate of oil supplied to the hydraulic actuator 23 and the operation direction of the hydraulic actuator 23.

[0017] The electric motor device 30 includes a power supply connection portion 31 , a power line 33 , an electric motor 35 , and an electric motor control device 40 .

[0018] 1, the power supply connection unit 31 can be connected to a power supply unit S via a power supply line C. The power supply connection unit 31 is configured to be able to connect to the power supply line C. The power supply connection unit 31 is mounted on the work machine body 10 and provided on, for example, the upper rotating body 13, for example, in the vicinity of the counterweight 13b. Specifically, for example, the power supply connection unit 31 is a slip ring or the like.

[0019] As shown in FIG. 2, the power line 33 is an electric wire connected to the electric motor 35. The power line 33 is mounted on the work machine body 10 (see FIG. 1) and arranged, for example, inside the upper rotating body 13 (see FIG. 1) (the same goes for the electric motor 35, a breaker 41 described later, and a connection switching unit 43 described later). The power line 33 is connected to the electric motor 35 and the power supply connection unit 31. The power line 33 can be electrically connected to a power supply unit S. The power line 33 is configured to be able to transmit a multi-phase (for example, three-phase) AC power supply. Specifically, for example, the power line 33 includes a U-phase 33u, a V-phase 33v, and a W-phase 33w.

[0020] The electric motor 35 drives the hydraulic pump 21. The electric motor 35 is driven (more specifically, rotationally driven) by power supplied from the power supply unit S. For example, the electric motor 35 is an AC motor driven by multi-phase (e.g., three-phase) AC power. For example, the electric motor 35 may be an induction motor (e.g., a squirrel-cage type, a wound type, etc.) or a synchronous motor. The rotation speed of the electric motor 35 during operation may be constant (fixed) or variable.

[0021] The motor control device 40 is a device (for example, a control panel) that controls the motor 35. The motor control device 40 includes a breaker 41, a connection switching unit 43, and a motor controller 45.

[0022] The breaker 41 breaks the circuit of the power line 33 when an overcurrent flows through the power line 33. The breaker 41 is a device that breaks the circuit by heat (a device that causes a thermal trip). The breaker 41 is provided for each phase (U phase 33u, V phase 33v, and W phase 33w) of the power line 33. The breaker 41 outputs information as to whether or not the circuit is broken to the motor controller 45.

[0023] The connection switching unit 43 is a device for starting the motor 35. The connection switching unit 43 is a device for reducing the current at the start of the motor 35 compared to the current at the time of operation of the motor 35. Specifically, for example, when the motor 35 is a three-phase induction motor, the connection switching unit 43 is a device for performing star-delta starting. The connection switching unit 43 switches the connections between the phases (U phase 33u, V phase 33v, W phase 33w) of the power line 33. The connection switching unit 43 switches the connections according to a command from the motor controller 45. When the motor 35 is started (in a starting phase described later), the connection switching unit 43 performs a connection that limits the current of the motor 35 (suppresses the current so as not to increase too much). Specifically, the connection switching unit 43 performs a star connection for the power line 33 during the starting phase. When the motor 35 is operating (in a running phase, which will be described later), the connection switching unit 43 performs connection so that the motor 35 can be operated at full load. Specifically, the connection switching unit 43 performs a delta connection for the power line 33 during the running phase. The connection switching unit 43 outputs information on the state of the connection to the motor controller 45.

[0024] The motor controller 45 is a computer that inputs and outputs signals, performs calculations (processing), stores information, etc. (The same applies to the work machine controller 51). For example, the functions of the motor controller 45 are realized by a calculation unit executing a program stored in a memory unit of the motor controller 45 (The same applies to the work machine controller 51). The motor controller 45 may be located anywhere. The motor controller 45 may be mounted on the work machine body 10 (see FIG. 1), for example, or may be located inside the upper rotating body 13 (see FIG. 1). The motor controller 45 may be located outside the work machine body 10 (see FIG. 1).

[0025] The motor controller 45 detects the power supply state from the power supply unit S to the motor 35. The motor controller 45 detects an abnormal power supply state that may affect the operation of the hydraulic circuit unit 20. The "effect on the operation of the hydraulic circuit unit 20" is, for example, reverse rotation of the hydraulic pump 21, fluctuations in the rotation speed, excessively high or low rotation speed, etc. The motor controller 45 detects the power supply state in at least two phases of the multi-phase (U-phase 33u, V-phase 33v, W-phase 33w) power line 33. The motor controller 45 may detect the power supply state in all phases of the power line 33. The motor controller 45 detects at least one of the voltage and current of the power line 33. This "at least one of the voltage and current" is included in the "power supply state."

[0026] The motor controller 45 performs error determination as to whether or not the power supply state is in an error state (described later). The motor controller 45 determines the operation phase (described later) of the motor 35. The motor controller 45 includes a setting unit (not shown) for setting the voltage and frequency to be supplied to the motor 35. This setting unit may be set by connecting a connector, or may be set by operating a button, switch, or the like. A reference value used for error determination is set based on a value set in the setting unit of the motor controller 45 (described later).

[0027] The electric motor controller 45 performs communication. For example, the electric motor controller 45 receives signals from the breaker 41, the connection switching unit 43, and the electric motor operation unit 55. The electric motor controller 45 may receive a signal from the work machine operation unit 53. For example, the electric motor controller 45 transmits a signal to the connection switching unit 43 and the work machine controller 51. The electric motor controller 45 may transmit a signal to the hydraulic control valve 25, or may transmit a signal to a valve (such as an electromagnetic proportional valve not shown) for controlling the hydraulic control valve 25. The communication performed by the electric motor controller 45 may include at least one of wired communication, wireless communication, and optical communication (the same applies to communication between other devices). Specifically, for example, the communication from the electric motor controller 45 to the work machine controller 51 may be CAN (Controller Area Network) communication. More specifically, the electric motor controller 45 may change the state of a signal to be transmitted to the work machine controller 51 depending on the content of the error in the power supply state. Note that communication from the work machine controller 51 to the notification unit 60 may be any type of communication, for example, CAN communication.

[0028] 2, the motor controller 45 is provided together with the breaker 41 and the connection switching unit 43 in the motor control device 40. On the other hand, at least one of the breaker 41, the connection switching unit 43, and the motor controller 45 does not have to be provided together in the motor control device 40, and may be provided at positions separated from each other.

[0029] The work machine controller 51 (mechatronics controller) controls the operation of the work machine body 10 (see FIG. 1). For example, the work machine controller 51 may cause the notification unit 60 to output a notification (described later). The work machine controller 51 may perform various controls in response to the operation of the work machine operation unit 53. The work machine controller 51 may be provided separately from the electric motor controller 45, or may be used in combination with the electric motor controller 45. As shown in FIG. 1, the work machine controller 51 is mounted on, for example, the work machine body 10, mounted on, for example, the upper rotating body 13, and disposed, for example, in the cab 13a. The work machine controller 51 may be mounted on the work machine body 10 and disposed outside the cab 13a, or may be disposed outside the work machine body 10.

[0030] The work machine operation unit 53 is for operating the electric work machine 1. The work machine operation unit 53 is operated by an operator. The work machine operation unit 53 operates the hydraulic actuator 23. More specifically, the work machine operation unit 53 operates the hydraulic control valve 25 (see FIG. 2 ) to operate the hydraulic actuator 23. For example, the work machine operation unit 53 is provided in the work machine body 10, specifically in the cab 13a (the same applies to the motor operation unit 55). For example, when the electric work machine 1 is remotely operated, the work machine operation unit 53 may be provided in a remote cab for remote operation (the same applies to the motor operation unit 55). For example, when the electric work machine 1 is automatically operated, the work machine operation unit 53 may be provided in a device (such as a tablet) that commands automatic operation (the same applies to the motor operation unit 55). For example, when the work machine operation unit 53 is provided in the cab 13a, the work machine operation unit 53 may output an electric signal or may output hydraulic pressure (pilot pressure). For example, when the work machine operation unit 53 is provided outside the work machine body 10, the work machine operation unit 53 may output an electrical signal.

[0031] The motor operation unit 55 is for performing operations related to the motor 35 shown in FIG. 2. The motor operation unit 55 is operated by an operator. For example, the motor operation unit 55 includes a key switch 55a and a start switch 55b. The key switch 55a is a switch for starting and stopping the motor 35. For example, the key switch 55a is a switch that can be switched between "on" and "off" (similar to the start switch 55b). For example, the key switch 55a is a switch for starting the work machine body 10. Specifically, the key switch 55a may be a button switch, a rotation switch, or a touch panel (similar to the start switch 55b). The start switch 55b is a switch for starting the start of the motor 35. As will be described later, when the start switch 55b is turned on with the key switch 55a turned on, the motor 35 starts. 2 and 3, the key switch 55a is indicated as a "key SW," and the start switch 55b is indicated as a "start SW." The key switch 55a and the start switch 55b shown in FIG. 2 may be configured as one switch, or may be configured as separate switches.

[0032] The notification unit 60 notifies the operator. The notification unit 60 outputs information related to the power supply state detected by the electric motor controller 45. When the electric motor controller 45 determines that the power supply state is in an error state, the notification unit 60 outputs information related to the error (e.g., the contents of the error). The notification unit 60 may output information related to the power supply state other than the information related to the error (e.g., the current, voltage, frequency, and the fact that the power supply state is normal). The notification unit 60 may notify by display or by sound.

[0033] The notification unit 60 is preferably configured to notify the worker when the worker is about to operate the work machine main body 10 shown in FIG. 1. For example, the notification unit 60 is preferably arranged at a position where the worker can be notified when the worker is about to operate the work machine operation unit 53. The notification unit 60 is preferably arranged near the work machine operation unit 53. Specifically, for example, the notification unit 60 may be provided in the work machine main body 10, in the upper rotating body 13, or in the cab 13a. Specifically, for example, the notification unit 60 may be a display screen (cluster gauge) or the like arranged in the cab 13a. The notification unit 60 may be provided outside the work machine main body 10, for example, in a remote cab for remote operation, or in a device (for example, a tablet, etc.) that commands automatic operation. The notification unit 60 may also be used as a device that provides notifications other than information about the power supply state of the electric motor 35 (see FIG. 2). The notification unit 60 may also serve as a device that notifies information (such as errors) related to the work machine body 10. In this case, the worker can receive notifications of both information related to the power supply state and information other than the information related to the power supply state from a single device.

[0034] (Activation) The electric working machine 1 is configured to operate as follows. The operation of the electric motor controller 45 shown in Fig. 2 is outlined as follows. The electric motor controller 45 sets a plurality of operating phases that indicate the state of the electric motor 35. The plurality of operating phases include a pre-start phase, a starting phase, and a running phase.

[0035] The pre-start phase is a state in which the motor 35 stops rotating. The pre-start phase is a state in which the motor controller 45 is operating and the motor 35 stops rotating. For example, the pre-start phase is a state in which the key switch 55a is on and the motor 35 stops rotating.

[0036] The starting phase is a state in which the motor 35 is starting. More specifically, the starting phase is a state in which the rotation speed of the motor 35 is increasing from a state in which the rotation of the motor 35 has been stopped. The starting phase is an operation phase between the pre-start phase and the running phase.

[0037] The running phase is a state in which the motor 35 is running after being started. The running phase is a state in which the motor 35 is rotating, and the fluctuation in the rotation speed of the motor device 30 is smaller than in the starting phase. Note that operation phases other than the pre-start phase, starting phase, and running phase may be set in the motor controller 45. Also, at least one of the pre-start phase, starting phase, and running phase may not be set in the motor controller 45.

[0038] A specific example of the processing of the electric motor controller 45 will be described with reference to the flowchart shown in Fig. 3. Below, each processing step (S11 to S43) shown in the flowchart will be described with reference to Fig. 3.

[0039] In step S11, the electric motor controller 45 shown in FIG. 2 judges whether or not the key switch 55a is on. If the key switch 55a is not on (NO in step S11), the electric motor controller 45 does nothing (returns to step S11). If the key switch 55a is on (YES in step S11), the electric motor controller 45 starts communication with the work machine controller 51. For example, the electric motor controller 45 may start communication after a predetermined time (e.g., 3 seconds) has elapsed after the key switch 55a is turned on. Note that the electric motor controller 45 may start (the electric motor controller 45 may start processing) when the key switch 55a is turned on. If the key switch 55a is on, the electric motor controller 45 starts the pre-start phase (step S21) and proceeds to step S22.

[0040] In step S22, the motor controller 45 determines whether or not there is an error in the pre-start phase (pre-start error). More specifically, the motor controller 45 determines whether or not the power supply state is in an error state in the pre-start phase. The contents of the pre-start error will be described later (the same applies to errors in other operation phases).

[0041] If there is a pre-start error (NO in step S22), the electric motor controller 45 causes the notification unit 60 to notify information related to the power supply state (step S22n). Specifically, for example, the electric motor controller 45 transmits information related to the power supply state to the work machine controller 51, and the work machine controller 51 causes the notification unit 60 to notify information related to the power supply state (similar to notifications in other operation phases). At this time, the notification unit 60 may notify the content of the error determined to be an error (such as "reverse phase" or "low voltage" described later) (similar to notifications in other operation phases). In this case, the worker can know the content of the error. The notification unit 60 may notify the voltage value, current value, frequency, etc. (similar to notifications in other operation phases).

[0042] If there is a pre-start error, the motor controller 45 may cause the notification unit 60 to give a notification (step S22n) and end the control flow without starting the motor 35. If there is a pre-start error and the motor 35 is started in an inappropriate power supply state, equipment (such as the motor 35 and the hydraulic circuit unit 20) may be damaged. By not starting the motor 35 when there is a pre-start error, damage to the equipment can be suppressed. Note that if there is a pre-start error, the motor controller 45 may cause the notification unit 60 to give a notification (step S22n) and start the motor 35 as is. If there is no pre-start error (YES in step S22), the motor controller 45 proceeds to step S23.

[0043] In step S23, the motor controller 45 judges whether the start switch 55b is on or not. If the start switch 55b is not on (NO in step S23), the motor controller 45 does nothing (returns to step S23). If the start switch 55b is on (YES in step S23), the motor controller 45 proceeds to step S31.

[0044] In step S31, the motor controller 45 ends the pre-start phase, starts the starting phase, and starts the motor 35. Specifically, the motor controller 45 switches the connection switching unit 43 to a connection (specifically, a star connection) for starting the motor 35. At this time, the motor controller 45 starts a start timer (described later).

[0045] During the start-up phase (while the electric motor 35 is starting), the rotation speed of the hydraulic pump 21 is smaller than the rotation speed at which the hydraulic actuator 23 can operate properly (the rotation speed is insufficient). Also, during the start-up phase, the torque of the hydraulic pump 21 is smaller than the torque at which the hydraulic actuator 23 can operate properly (the torque is insufficient). Therefore, the electric motor controller 45 may control the hydraulic actuator 23 not to operate during the start-up phase. Specifically, for example, the electric motor controller 45 may block a command from the work machine operation unit 53 to the hydraulic control valve 25 during the start-up phase (for example, may perform a lever lock). Note that the electric motor controller 45 may enable the hydraulic actuator 23 to operate during the start-up phase. Next, the electric motor controller 45 proceeds to step S32.

[0046] In step S32, the motor controller 45 judges whether or not there is an error in the starting phase (starting error). More specifically, the motor controller 45 judges whether or not the power supply state is in an error state in the starting phase. If there is an error during starting (NO in step S32), the motor controller 45 notifies the notification unit 60 of information on the power supply state (e.g., the contents of the error, etc.) (step S32n). Then, the motor controller 45 may continue starting the motor 35 or may proceed to step S33. If there is an error during starting, the motor controller 45 may cause the notification unit 60 to notify (step S32n), stop starting the motor 35, or end the control flow (see the two-dot chain arrow after step S32n). If there is no error during starting (YES in step S32), the motor controller 45 continues starting the motor 35 and proceeds to step S33.

[0047] In step S33, the motor controller 45 determines whether or not a "predetermined startup time" has elapsed since the start of the startup phase (startup timer). The predetermined startup time is a time required to start the motor 35 (specifically, for example, 3 seconds) and is set in the motor controller 45. If the predetermined startup time has not elapsed (NO in step S33), the motor controller 45 returns to step S32 and continues the startup phase. If the predetermined startup time has elapsed (YES in step S33), the motor controller 45 proceeds to step S41.

[0048] In step S41, the motor controller 45 ends the starting phase and starts the running phase. Specifically, the motor controller 45 switches the connection switching unit 43 to a connection for operating the motor 35 (specifically, a delta connection). Next, the motor controller 45 proceeds to step S42.

[0049] In step S42, the motor controller 45 judges whether or not there is an error in the operation phase (operation error). More specifically, the motor controller 45 judges whether or not the power supply state is in an error state in the operation phase. If there is an operation error (NO in step S42), the motor controller 45 notifies the notification unit 60 of information on the power supply state (e.g., the contents of the error, etc.) (step S42n). Then, the motor controller 45 may continue the operation of the motor 35, or may proceed to step S43. If there is an operation error, the motor controller 45 may stop the operation of the motor 35, or may end the control flow (see the two-dot chain arrow after step S42n). If there is no operation error (YES in step S42), the motor controller 45 proceeds to step S43.

[0050] In step S43, the motor controller 45 judges whether the key switch 55a is off. If the key switch 55a is on (NO in step S43), the motor controller 45 continues the operation of the motor 35 and returns to step S42. If the key switch 55a is off (YES in step S43), the motor controller 45 stops the operation of the motor 35. In this case, the motor controller 45 ends the control. For example, the motor controller 45 may completely stop after a predetermined time (e.g., about 30 seconds) has elapsed since the key switch 55a was turned off. If the key switch 55a is off, the motor controller 45 stops communication with the work machine controller 51. For example, the motor controller 45 may stop communication with the work machine controller 51 after a predetermined time (e.g., about 30 seconds) has elapsed since the key switch 55a was turned off. If the key switch 55a is off, the motor controller 45 may release the error. The electric motor controller 45 may reset the error under conditions other than the key switch 55a being turned off.

[0051] (Details of error detection) The motor controller 45 performs an error determination as to whether or not the power supply state is in an error state. The contents of the error determined by the motor controller 45 may be set in various ways. The contents of the error include, for example, reverse phase, excessive voltage, undervoltage, voltage loss, overcurrent, undercurrent, current loss, overfrequency, underfrequency, thermal trip, and abnormal wiring state (described in detail later).

[0052] The motor controller 45 has a condition for error determination (error condition) for each of a plurality of operation phases. It is preferable that an appropriate error condition is set in the motor controller 45 according to the operation phase. For example, the presence or absence of an error condition for a certain error content (e.g., reverse phase) may differ for each operation phase. More specifically, an error condition may be set in a certain operation phase and not set in another operation phase. Also, a different error condition may be set for a certain error content (e.g., undervoltage) for each operation phase. Specifically, for example, the threshold value of the error condition may differ for each operation phase. Specific examples of error content, operation phase, and error condition are shown in Table 1.

[0053] [Table 1]

[0054] (reverse phase) The electric motor controller 45 detects whether the phase rotation of the AC power input to the electric motor 35 is reversed (i.e., the phase is reversed). For example, the electric power input to the electric motor 35 may be in the reverse phase due to an incorrect connection of at least one of the power supply line C, the power supply connection unit 31, and the power line 33. If the electric power input to the electric motor device 30 is in the reverse phase, the electric motor 35 may rotate in the reverse direction, causing the hydraulic pump 21 to rotate in the reverse direction, which may damage the hydraulic pump 21. For example, the electric motor controller 45 detects the phase sequence by detecting the waveform of the voltage or current of the power line 33. Then, the electric motor controller 45 determines whether the detected phase sequence is equal to a preset phase sequence.

[0055] In the example shown in Table 1, whether or not the error condition of reverse phase is set varies depending on the operation phase. Specifically, the error condition of reverse phase is set in the pre-start phase, but is not set in the starting phase or the running phase. In this case, the motor controller 45 determines whether or not the phase is reverse in the pre-start phase, but does not determine whether or not the phase is reverse in the starting phase or the running phase.

[0056] The error conditions listed in Table 1 are merely examples, and various error conditions can be set. For example, the motor controller 45 may determine whether or not there is a reverse phase in at least one of the starting phase and the running phase. Whether or not an error condition is set in each operating phase can be set in various ways, and this also applies to the contents of other errors.

[0057] (Voltage too low) The motor controller 45 detects whether the voltage input to the motor 35 is too low. For example, when an inappropriate power source is connected to the electric work machine 1, the voltage input to the motor 35 may be abnormal (the same applies to excessive voltage and voltage missing phase). For example, the motor controller 45 detects whether the voltage is too low for each phase (U phase 33u, V phase 33v, W phase 33w) of the power line 33 (the same applies to excessive voltage and voltage missing phase). The motor controller 45 compares the voltage of the power line 33 (detected voltage) with a threshold value to determine whether the voltage is too low (the same applies to excessive voltage and voltage missing phase).

[0058] Specifically, when the detected voltage remains below a threshold value (for example, "below set voltage value -Va (e.g., -5%)" in Table 1) for a certain period of time (for example, "Ta (e.g., 3 seconds or more)" in Table 1), the low-voltage error condition is met.

[0059] The motor controller 45 judges whether the voltage is too low, for example, in the pre-start phase, the starting phase, and the operating phase (the same applies to excessive voltage, voltage loss, frequency, excessive frequency, and frequency loss). The error conditions in judging whether the voltage is too low differ between the pre-start phase, the starting phase, and the operating phase (the same applies to excessive voltage and voltage loss).

[0060] More specifically, the appropriate voltage of the power line 33 varies depending on the operation phase of the motor 35. Specifically, the voltage is lower when the motor 35 is starting up than before starting up or during operation. Therefore, the voltage threshold value for determining whether the voltage is too low (e.g., "set voltage value -Va (e.g., -5%)" in Table 1) is preferably smaller in the starting phase than in the operating phase. This threshold value is preferably smaller in the starting phase than in the operating phase. This threshold value may be smaller in the operating phase than in the pre-starting phase.

[0061] The time condition (duration) included in the under-voltage error condition (for example, "Continues for Ta (e.g., 3 seconds or more)" in Table 1) may be different for each operating phase (the same applies to over-voltage and voltage loss phase). This duration may be shorter in the starting phase than in the pre-starting phase. This duration may be shorter in the starting phase than in the running phase. This duration may be shorter in the pre-starting phase than in the running phase.

[0062] The error condition of the voltage being too low in the pre-start phase in Table 1 is "a voltage below the set voltage value -Va (e.g. -5%) continues for Ta (e.g. 3 seconds) or more." The "set voltage value -Va (e.g. -5%) or less will be explained. The "set voltage value -Va" means "a value obtained by subtracting Va from the set voltage value." The "set voltage value" is a value set in the motor controller 45, and is set, for example, by a setting unit (connection of a connector, etc.) not shown in the figure (the same applies to the set frequency described below). The value of "Va" is, for example, a value determined based on the set voltage value (the same applies to Vb to Vi in Table 1). Specifically, the value of "Va" is a value obtained by multiplying the set voltage value by a certain ratio (the same applies to Vb to Vi). More specifically, in this example, the value of "Va" is a value that is 5% of the set voltage value. Also, "Ta" in "continues for Ta (e.g. 3 seconds) or more" is a time (the same applies to Tb to Tr), and in this example, it is 3 seconds.

[0063] As mentioned above, the error conditions listed in Table 1 are merely examples, and various error conditions can be set. Specifically, for example, the value of "Va" does not have to be a value (relative value) determined based on the set voltage value, and may be an absolute value (e.g., 10V, etc.) (the same applies to the thresholds of other error conditions). Also, each numerical value listed in Table 1 (e.g., "-5%", "3 seconds", etc.) is merely an example to make it easier to visualize the magnitude relationship of each threshold, and various error conditions can be set.

[0064] (Excessive voltage) The motor controller 45 detects whether or not the voltage input to the motor 35 is excessive. Specifically, when the detected voltage remains equal to or higher than a threshold value (for example, "set voltage value + Vd (e.g. +5%) or higher" in Table 1) for a certain period of time, an excessive voltage error condition is satisfied.

[0065] When the motor 35 is starting up, the voltage is lower than before starting up or during operation. Therefore, the voltage threshold value for determining whether the voltage is excessive (for example, "set voltage value + Vd (e.g., +5%)" in Table 1) is preferably smaller in the starting phase than in the pre-start phase. This threshold value is preferably smaller in the starting phase than in the operating phase. This threshold value may be smaller in the pre-start phase than in the operating phase. "Set voltage value + Vd (e.g., +5%)" means "the set voltage value plus Vd."

[0066] (Voltage phase loss) The motor controller 45 detects whether or not at least one of the phases (U-phase 33u, V-phase 33v, W-phase 33w) of the motor 35 is in a phase loss state. The motor controller 45 may detect whether or not there is a phase loss based on the voltage, or may detect based on the current. A phase loss detected based on the voltage is referred to as a "voltage phase loss," and a phase loss detected based on the current is referred to as a "current phase loss" (described later). A phase loss may occur, for example, when an inappropriate power source is connected to the electric working machine 1, or when at least one of the power supply line C, the power source connection unit 31, and the power line 33 is erroneously connected or disconnected.

[0067] Specifically, when the detected voltage remains below a threshold value (for example, "set voltage value -Vg (e.g., -70%) or less" in Table 1) for a certain period of time, the error condition of voltage loss phase is satisfied. The voltage threshold value for determining whether or not there is a voltage loss phase (for example, "set voltage value -Vg (e.g., -70%)" in Table 1) does not have to be different for each operating phase, and may be different.

[0068] (Excessive frequency) The motor controller 45 detects whether the frequency of the AC power input to the motor 35 is excessive. For example, when an inappropriate power source is connected to the electric work machine 1, the frequency input to the motor 35 may become abnormal (the same applies to an under-frequency). When the frequency input to the motor 35 is excessive, the motor 35 may over-rotate (rotate at a higher rotation speed than expected), causing the hydraulic pump 21 to over-rotate, and the operating speed of the hydraulic actuator 23 may become excessive. For example, the motor controller 45 detects the frequency by detecting the waveform of the voltage or current of the power line 33. The motor controller 45 then compares the detected frequency with a threshold value to determine whether the frequency is excessive (the same applies to an under-frequency).

[0069] Specifically, when the detected frequency remains above a threshold (for example, “set frequency + Fj (e.g. +5%) or more” in Table 1) for a certain period of time, the excessive frequency error condition is met.

[0070] The error conditions in determining whether the frequency is too high may be different for the pre-start phase, the starting phase, and the operating phase, or may be the same for at least two operating phases (the same applies for the under-frequency). The frequency threshold for determining whether the frequency is too high (e.g., "set frequency + Fj (e.g., +5%)" in Table 1) may be different for each operating phase, or may not be different (the same applies for the under-frequency). For example, this threshold may be equal for the starting phase and the operating phase, and may be different between them and the pre-start phase (the same applies for the under-frequency). For example, this threshold may be smaller in the pre-start phase than in the starting phase, or smaller in the pre-start phase than the operating phase.

[0071] The time condition (duration) included in the over-frequency error condition (for example, "continue for Tj (e.g., 3 seconds or more)" in Table 1) may be shorter in the pre-start-up phase than in the starting up phase or the running phase (the same applies to under-frequency). During the starting up phase, it may be possible that the detected frequency is detected to be at or above the threshold, and this state may continue into the running phase. In this case, if the sum of the duration of the starting up phase and the duration of the running phase is Tk (e.g., 5 seconds) or more, it may be determined that an error has occurred (the same applies to under-frequency). Also, if the duration of only the running phase is Tk (e.g., 5 seconds) or more, it may be determined that an error has occurred (the same applies to under-frequency).

[0072] The error condition for excessive frequency in the pre-start phase in Table 1 is "Set frequency + Fj (e.g. +5%) or more continues for Tj (e.g. 3 seconds) or more." "Set frequency + Fj" means "the set frequency plus Fj." The value of "Fj" is a value determined based on the set voltage value (the same applies to Fk to Fn in Table 1). Specifically, the value of "Fj" is a value obtained by multiplying the set voltage value by a certain percentage (the same applies to Fk, Fm, and Fn). More specifically, in this example, the value of "Fj" is 5% of the set frequency.

[0073] (too low frequency) The electric motor controller 45 detects whether or not the frequency of the AC power input to the electric motor 35 is too low. If the frequency input to the electric motor 35 is too low, the rotation speed of the electric motor 35 becomes insufficient (it rotates at a rotation speed lower than the expected rotation speed), the rotation speed of the hydraulic pump 21 becomes insufficient, and the operating speed of the hydraulic actuator 23 may become insufficient.

[0074] Specifically, when the detected frequency is equal to or lower than a threshold value (for example, equal to or lower than "Set Frequency - Fm (e.g., -5%)" in Table 1) and this state continues for a certain period of time, an error condition of too low frequency is satisfied. The frequency threshold value (for example, "Set Frequency - Fm (e.g., -5%)" in Table 1) for determining whether the frequency is too low may be smaller in the pre-start phase than in the in-start phase, or may also be smaller in the pre-start phase than in the in-operation phase. "Set Frequency - Fm (e.g., -5%)" means "the value obtained by subtracting Fm from the set frequency".

[0075] (Too small current) The motor controller 45 detects whether the current flowing through the motor 35 is too small. For example, when an inappropriate power supply is connected to the power-operated work machine 1, the current flowing through the motor 35 may become abnormal (the same applies to excessive current and current phase loss). For example, the motor controller 45 detects whether the current is too small for at least two of the respective phases (U phase 33u, V phase 33v, W phase 33w) of the power line 33 (the same applies to excessive current and current phase loss). The motor controller 45 determines whether the current is too small by comparing the current (detected current) of the power line 33 with a threshold value (the same applies to excessive current and current phase loss).

[0076] Specifically, when the detected current is within a certain range (for example, "Set Current Value - Io (e.g., -95%) < I ≤ Set Current Value - Ip (e.g., -80%)" in Table 1) and this state continues for a certain period of time, an error condition of too small current is satisfied.

[0077] Whether an error condition for overcurrent is set or not varies depending on the operating phase (the same applies to overcurrent and current phase loss). Specifically, the error condition for overcurrent is set in the running phase and not in the pre-start phase or the starting phase (the same applies to overcurrent and current phase loss). The motor controller 45, for example, does not determine whether the current is too low in the pre-start phase and the starting phase, but determines whether the current is too low in the running phase (the same applies to overcurrent and current phase loss). Note that an error condition for too low current may be set in the pre-start phase or the starting phase (the same applies to overcurrent and current phase loss).

[0078] The error condition for too low current in the pre-start phase in Table 1 is "The set current value - Io (e.g., -95%) < I ≤ the set current value - Ip (e.g., -80%) continues for To (e.g., 5 seconds) or more". "The set current value - Io" means "the value obtained by subtracting Io from the set current value" (the same applies to Ip). The "set current value" may be calculated, for example, from the set voltage value set in the motor controller 45, or may be set in the motor controller 45 regardless of the set voltage value. The value of "Io" is a value determined based on the set current value (the same applies to Ip and Ir in Table 1). Specifically, the value of "Io" is a value obtained by multiplying the set current value by a certain ratio (the same applies to Ip and Ir). More specifically, in this example, the value of "Ip" is 95% of the set current value. "I" is the current value detected by the motor controller 45 (the same applies to the error condition for overcurrent in Table 1).

[0079] (Overcurrent) The motor controller 45 detects whether the current flowing through the motor 35 is excessive. Specifically, when the detected current is equal to or greater than a threshold value (e.g., "Rq (e.g., 150%) of the set current value" in Table 1) for a certain period of time, the error condition for overcurrent is satisfied. "Rq" is a ratio multiplied by the set current value and is greater than 100%.

[0080] (Current phase loss) The motor controller 45 detects whether or not there is a missing phase based on the current. Specifically, when the detected current is equal to or lower than a threshold (for example, "set current value -Ir (for example, -95%) or lower" in Table 1) continues for a certain period of time or more, the error condition of a missing current phase is satisfied. For example, the current threshold (for example, "set current value -Ir (for example, -95%)" in Table 1) for determining whether or not there is a missing voltage phase may be equal to the lower limit of an insufficient current (for example, "set current value -Io (for example, -95%)" in Table 1).

[0081] (Thermal Trip) The motor controller 45 detects whether the circuit is interrupted by the breaker 41 (whether a thermal trip has occurred). This detection is performed constantly, during the pre-start phase, the start-up phase, and the running phase. The motor controller 45 determines that an error has occurred when the circuit is interrupted by the breaker 41 (i.e., the thermal trip error condition is satisfied).

[0082] (Connection status abnormal) The motor controller 45 detects whether the connection switching unit 43 has switched the connection state normally. Specifically, the motor controller 45 detects whether the connection switching unit 43 has switched from star connection to delta connection when switching from the starting phase to the operating phase. If the motor controller 45 detects that the connection switching unit 43 has not switched from star connection to delta connection, it determines that an error has occurred due to an abnormal connection state (i.e., the error condition for an abnormal connection state is satisfied).

[0083] Specifically, the error condition for abnormal wiring state is satisfied when the average value of the current in a certain time range of the starting phase multiplied by a predetermined percentage (e.g., 150%) is equal to or greater than the average value of the current in a certain time range of the operating phase. The "certain time range of the starting phase" is, for example, a time range (e.g., 2 to 2.5 seconds) after a predetermined time has elapsed since the start-up phase switches to the starting phase. The "certain time range of the operating phase" is, for example, a time range (e.g., 0.5 to 1 second) after the start-up phase switches to the operating phase.

[0084] (Examples of power supply abnormalities) Specific examples of cases in which an abnormality in the power supply state occurs are as follows. The work machine body 10 (electric work machine 1) shown in FIG. 1 may be carried into the work area from outside the work area (yard). In this case, the work machine body 10 may be transported to the vicinity of the work area by a transport vehicle (trailer, etc.). In this case, the work machine body 10 may dismount from the transport vehicle by itself and move from the transport vehicle to the work area by itself. When this self-propelling, the power supply unit S of the work area may not be connected to the work machine body 10. If the power supply unit S is not connected to the work machine body 10, the work machine body 10 cannot self-propel. Therefore, the work machine body 10 may be connected to a portable power supply unit S (generator) and receive power supply from this portable power supply unit S to self-propel. After that, when the work machine body 10 arrives at the work area, the work machine body 10 is connected to a power supply unit S (power supply equipment) provided in the work area and receives power supply from this power supply unit S. In this case, the electric wires are changed several times, such as changing the connection between the power supply connection unit 31 and the power supply line C. If an erroneous connection occurs at this time, there is a risk that the power supply state to the electric motor 35 (see FIG. 2) will become abnormal.

[0085] Furthermore, while the electric working machine 1 is being used (during work), an abnormality may occur in the power supply unit S, an abnormality (e.g., a break) in the power supply line C, an abnormality (e.g., a poor connection) in the power connection unit 31, or an abnormality (e.g., a break) in the power line 33. When this occurs, there is a risk that the state of the power supply to the electric motor 35 shown in FIG. 2 may become abnormal.

[0086] If the electric work machine 1 operates while the power supply to the electric motor 35 remains abnormal, for example, the electric motor 35 may be damaged or may not be able to perform as intended (cannot produce the intended output). As a result, the hydraulic pump 21 and the hydraulic actuator 23 driven by the electric motor 35 may be damaged or may not be able to perform as intended.

[0087] On the other hand, in the electric work machine 1 of this embodiment, the power supply state is output to the notification unit 60. As a result, the worker is more likely to notice an abnormality in the power supply state to the electric motor 35. As a result, the worker is more likely to take appropriate measures regarding the power supply state to the electric motor 35. As a result, it is possible to prevent the problem that the electric work machine 1 operates with the power supply state to the electric motor 35 being inappropriate and the equipment constituting the electric work machine 1 (such as the electric motor 35, hydraulic pump 21, and hydraulic actuator 23) is damaged. It is also possible to prevent the problem that the electric work machine 1 operates with the power supply state to the electric motor 35 being inappropriate and the equipment constituting the electric work machine 1 is unable to exhibit its original performance.

[0088] (Effects of the first invention) The effects of the electric work machine 1 shown in Fig. 2 are as follows. The electric work machine 1 comprises a work machine body 10 (see Fig. 1), an electric motor 35, a hydraulic pump 21, a hydraulic actuator 23, an electric motor controller 45, and a notification unit 60. As shown in Fig. 1, the work machine body 10 is connectable to a power supply unit S. The electric motor 35 is mounted on the work machine body 10 and is driven by electricity supplied from the power supply unit S. The hydraulic pump 21 shown in Fig. 2 is mounted on the work machine body 10 (see Fig. 1) and is driven by the electric motor 35. The hydraulic actuator 23 is mounted on the work machine body 10 (see Fig. 1) and is driven by pressure oil discharged by the hydraulic pump 21.

[0089] [Configuration 1] The electric motor controller 45 detects the state of power supply from the power supply unit S to the electric motor 35. The notification unit 60 outputs information related to the power supply state detected by the electric motor controller 45.

[0090] In the above [Configuration 1], the state of power supply from the power supply unit S to the electric motor 35 is output by the notification unit 60. Therefore, information related to the power supply state can be notified to the operator. As a result, it is possible to prevent the operator from operating the electric work machine 1 while the state of power supply to the electric motor 35 is not appropriate.

[0091] (Effects of the second invention) [Configuration 2] The electric motor 35 is driven by multiple-phase AC power. The electric motor controller 45 detects at least one of the voltage and the current of at least two of the multiple phases as the power supply state.

[0092] In the above [Configuration 2], information on at least two of the multiple phases is detected. Therefore, it is possible to detect whether the power input to the electric motor 35 is in reverse phase. Therefore, it is possible to detect reverse rotation of the electric motor 35. As a result, it is possible to detect reverse rotation of the hydraulic pump 21. Also, in the above [Configuration 2], at least one of the voltage and the current is detected. From the time change of at least one of the voltage and the current, it is possible to detect the frequency of the AC power input to the electric motor 35. Therefore, it is possible to detect the rotation speed of the electric motor 35. As a result, it is possible to detect the rotation speed of the hydraulic pump 21. As a result, it is possible to detect an abnormality in the flow rate of the pressure oil discharged from the hydraulic pump 21, and it is possible to detect an abnormality in the speed of the hydraulic actuator 23.

[0093] (Effects of the third invention) [Configuration 3] The motor controller 45 performs error determination as to whether or not the power supply state is in an error state (see steps S22, S32, and S42 in FIG. 3). The motor controller 45 sets a plurality of operation phases that indicate the state of the motor 35. The plurality of operation phases include a pre-start phase in which the rotation of the motor 35 is stopped, a start-up phase in which the motor 35 is starting, and a running phase in which the motor 35 is operating after starting. The motor controller 45 has a condition for error determination for each of the plurality of operation phases (see Table 1 above).

[0094] The above [Configuration 3] provides the following effect. The appropriate power supply state changes depending on the state (operation phase) of the electric motor 35. Therefore, in the above [Configuration 4], the electric motor controller 45 has an error judgment condition (error condition) for each operation phase. Therefore, when an appropriate error condition is set according to the operation phase, the electric motor controller 45 can perform an appropriate error judgment according to the operation phase. As a result, it is possible to suppress a case where an error is judged to be present when the power supply state is not abnormal, or a case where an error is not judged to be present when the power supply state is abnormal (erroneous judgment).

[0095] (Effect of the fourth invention) [Configuration 4] As shown in FIG. 1, the hydraulic actuator 23 includes a travel motor 23a for causing the work machine body 10 to travel.

[0096] In the above [Configuration 4], in order for the work machine main body 10 (the electric work machine 1) to propel itself, power must be supplied to the electric work machine 1. Therefore, in the electric work machine 1, there is a higher possibility that the power supply line C will be reconnected, and there is a higher possibility of a misconnection, compared to machines that do not propel themselves using electricity. Therefore, in the electric work machine 1, it is more important to notify the operator of the power supply status, compared to machines that do not propel themselves using electricity. In the electric work machine 1, the above [Configuration 1] makes it possible to notify the operator of the power supply status.

[0097] (Modification) The above embodiment may be modified in various ways. For example, the configuration (e.g., arrangement, shape, etc.) of each component of the above embodiment may be changed. For example, the connection of each component shown in FIG. 2 may be changed. For example, the order of steps in the flowchart shown in FIG. 3 may be changed, or some of the steps may not be performed. For example, the set value, threshold value, range, etc. (e.g., threshold value of an error condition, etc.) may be constant, may be changed by manual operation, or may be automatically changed according to some condition. For example, the number of components may be changed, or some of the components may not be provided. For example, the fixing or connection between the components may be direct or indirect. For example, what has been described as multiple different members or parts may be treated as one member or part. For example, what has been described as one member or part may be provided as multiple different members or parts. [Explanation of symbols]

[0098] 1 Electrical work machines 10. Working machine body 21 Hydraulic pump 23 Hydraulic Actuator 23a Driving motor 35 Electric motor 45 Motor Controller 60 Notification Department S power supply unit

Claims

1. A work machine body connectable to a power supply unit; an electric motor mounted on the working machine body and driven by power supplied from the power supply unit; a hydraulic pump mounted on the work machine body and driven by the electric motor; a hydraulic actuator mounted on the work machine body and driven by pressure oil discharged from the hydraulic pump; a motor controller for detecting a state of power supply from the power supply unit to the motor; a notification unit that outputs information regarding the power supply state detected by the electric motor controller; Equipped with The electric motor controller performs an error determination as to whether or not the power supply state is an error state, and sets a plurality of operation phases that indicate the state of the electric motor; The plurality of operational phases include: a pre-start phase during which the motor is stopped; a starting phase in which the electric motor is starting; a running phase in which the motor is running after start-up; Including, The electric motor controller has a condition for determining the error for each of the plurality of operation phases. Electric work machinery.

2. 2. The electric operating machine according to claim 1, The electric motor is driven by a multi-phase AC power. The motor controller detects at least one of a voltage and a current of at least two phases among a plurality of phases as the power supply state. Electric work machinery.

3. An electric operating machine as claimed in claim 1 or 2, The hydraulic actuator includes a travel motor for driving the work machine body. Electric work machinery.

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