Work machine

Abstract

The purpose of the present invention is to provide an electric work machine that does not require an operator to switch operation modes consciously and has excellent operability. An electric work machine (1) powered by electric power supplied from an external power source (15) is provided with: an electric motor (18) for driving a hydraulic pump (19) for supplying hydraulic oil to a hydraulic actuator (9); an ignition switch (22) that allows or stops the supply of power to the electric motor (18); a latch lever (23) that allows or stops the supply of hydraulic oil to the hydraulic actuator (9); and a controller (21) that controls the operation of the work machine (1). The controller switches the operation mode of the work machine (1) on the basis of the state of the ignition switch (22), the state of the door lock lever (23), and the supply state of power from the external power source (15).

Description

Technical Field

[0001] The present invention relates to an electric working machine. Background Art

[0002] There are known electric working machines that use a commercial external power supply as a power supply source. Many of these working machines can operate in a plurality of different operation modes depending on the power supply method from the external power supply.

[0003] Patent document 1 discloses a working vehicle capable of switching between a driving mode and a charging mode, wherein the driving mode is a mode in which an electric motor is driven by a battery charged by power supplied from an external power source or by power supplied from an external power source, and the charging mode is a mode in which the battery is charged by power supplied from an external power source.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-308881 Summary of the invention

[0007] However, in order to switch the operation mode of the work vehicle disclosed in Patent Document 1, the operator cannot switch the operation mode unless he operates a dedicated input device such as a charging switch, which wastes energy.

[0008] In view of the above, an object of the present invention is to provide an electric working machine which does not require an operator to consciously switch an operation mode and has excellent operability.

[0009] In order to solve the above-mentioned problems, the working machine of the present invention is an electric working machine that uses electricity supplied from an external power source as power, and is characterized in that the working machine has: an electric motor that drives a hydraulic pump that supplies working oil to a hydraulic actuator; an ignition switch that allows or stops the supply of power to the electric motor; a locking device that allows or stops the supply of the working oil to the hydraulic actuator; and a controller that controls the movement of the working machine, and the controller switches the movement mode of the working machine based on the state of the ignition switch, the state of the locking device, and the supply state of power from the external power source.

[0010] Effects of the Invention

[0011] According to the present invention, it is possible to provide an electric working machine which does not require an operator to consciously switch an operation mode and has excellent operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1It is a side view of the working machine of this embodiment.

[0013] Figure 2 Yes means Figure 1 A block diagram showing the configuration of a drive system for a working machine shown.

[0014] Figure 3 yes Figure 2 The state transition diagram of the operation mode of the working machine shown.

[0015] Figure 4 Yes Description Figure 3 The two-way mode is shown in the figure.

[0016] Figure 5 Yes means switching Figure 3 A timing chart showing an example of operation of the working machine in the operation mode shown.

[0017] Figure 6 Yes means switching Figure 3 A timing chart of another operation example of the working machine in the operation mode shown.

[0018] Figure 7 It is a diagram for explaining a modified example of the external power detection device. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described using the drawings. Unless otherwise specified, components denoted by the same reference numerals in each embodiment have the same functions in each embodiment, and description thereof will be omitted.

[0020] Figure 1 It is a side view of the working machine 1 according to the present embodiment.

[0021] The working machine 1 is an electric working machine that uses the power supplied from the external power source 15 as a power source. Specifically, the working machine 1 is an electric working machine that uses at least one of the external power source 15 and the internal storage battery 7 charged by the power supplied from the external power source 15 as a power supply source. The working machine 1 may also be an electric construction machine such as an electric excavator, an electric wheel loader, or an electric crane. In this embodiment, Figure 1 As shown, an electric excavator is described as an example of the working machine 1 .

[0022] Figure 1 The working machine 1 shown is composed of a lower traveling structure 2 and an upper revolving structure 3. The lower traveling structure 2 travels via crawlers driven by a traveling hydraulic motor 4. The upper revolving structure 3 is driven by a revolving hydraulic motor 5 and rotates relative to the lower traveling structure 2.

[0023] The upper rotating body 3 has a front working device 6, a battery 7, a cabin 8, a power conversion device 14, etc. The front working device 6 has a boom 11, an arm 12, and a bucket 13, etc. The boom 11, the arm 12, and the bucket 13 are driven by a boom hydraulic cylinder 10a, an arm hydraulic cylinder 10b, and a bucket hydraulic cylinder 10c provided on the upper rotating body 3, respectively, and can perform excavation work.

[0024] The power conversion device 14 is a device that converts the power supplied from the external power supply 15 via the power supply cable 16 into power that can be used in the working machine 1. The external power supply 15 can be, for example, a power supply connected to a commercial power distribution network owned by a power company, or a large-capacity power storage device that can be transported. The external power supply 15 of this embodiment can also be a power supply source that supplies AC power.

[0025] In the present embodiment, the hydraulically driven actuators such as the boom hydraulic cylinder 10a, the dipper arm hydraulic cylinder 10b, the bucket hydraulic cylinder 10c, the travel hydraulic motor 4 or the swing hydraulic motor 5 may be collectively referred to as the hydraulic actuator 9. The hydraulic actuator 9 is driven by supplying working oil from a hydraulic pump 19 provided in the working machine 1.

[0026] Figure 2 Yes means Figure 1 2 is a block diagram showing the configuration of a drive system of the working machine 1 shown.

[0027] The drive system of the working machine 1 includes a battery 7, a power conversion device 14, an electric motor 18, a hydraulic pump 19, a control valve 20, a hydraulic actuator 9, a controller 21, an ignition switch 22, a door lock rod 23 (locking device), an operating lever 24, an operation permission judgment device 25, and a notification device 27. The power conversion device 14 includes a converter 17a and an inverter 17b.

[0028] The battery 7 is, for example, a secondary battery such as a lithium-ion battery. The battery 7 is charged by power supplied from the external power supply 15 and converted by the converter 17a. The battery 7 supplies the charged power to the electric motor 18 via the inverter 17b. The battery 7 has a built-in relay. The relay built into the battery 7 is turned on / off controlled by the power supply permission signal SG5 from the control unit 21a of the controller 21. Thus, the power supply from the battery 7 to the electric motor 18 is allowed or stopped.

[0029] The converter 17a converts the AC power supplied from the external power supply 15 into DC power, and supplies it to the battery 7 and the inverter 17b. The converter 17a has a built-in external power detection device 26 for detecting the power supply from the external power supply 15. The external power detection device 26 is composed of, for example, a sensor (such as a voltage sensor) for detecting the power supplied from the external power supply 15. If the external power detection device 26 detects the power supply from the external power supply 15, it sends an external power detection signal SG3 to the controller 21. The converter 17a has a built-in relay. The relay built into the converter 17a is turned on / off controlled by the power supply permission signal SG4 from the control unit 21a of the controller 21. As a result, the power supply from the converter 17a to the battery 7 and the inverter 17b is allowed or stopped.

[0030] The inverter 17b converts the DC power supplied from the converter 17a or the battery 7 into AC power, and supplies it to the electric motor 18. At this time, the inverter 17b controls the AC power according to the speed command signal from the controller 21. Thus, the inverter 17b drives the electric motor 18 according to the speed command signal. The inverter 17b has a conversion element such as an IGBT built in. The conversion element built into the inverter 17b is turned on / off controlled by the power supply permission signal SG6 from the control unit 21a of the controller 21. Thus, the power supply from the inverter 17b to the electric motor 18 is allowed or stopped.

[0031] The electric motor 18 is an AC motor that is operated by the AC power supplied from the inverter 17b. The rotating shaft of the electric motor 18 is connected to the rotating shaft of the hydraulic pump 19. The electric motor 18 drives the hydraulic pump 19.

[0032] The hydraulic pump 19 is driven by the electric motor 18 and supplies hydraulic oil to the hydraulic actuator 9 via the control valve 20. The hydraulic pump 19 supplies hydraulic oil at a discharge amount corresponding to the operating lever signal SG7 sent from the operating lever 24. The control valve 20 distributes the hydraulic oil supplied from the hydraulic pump 19 to the boom hydraulic cylinder 10a, the arm hydraulic cylinder 10b, the bucket hydraulic cylinder 10c, the travel hydraulic motor 4, the swing hydraulic motor 5, etc.

[0033] The ignition switch 22 is a switch operated by the operator to start or stop (shut down) the working machine 1. The ignition switch 22 starts or stops the working machine 1, for example, when the operator turns the key cylinder to on or off. When the working machine 1 is started or stopped, the power supply to the electric motor 18 is allowed or stopped. In other words, the ignition switch 22 allows or stops the power supply to the electric motor 18. When the ignition switch 22 is operated to a state in which the power supply to the electric motor 18 is allowed, the ignition signal SG1 is sent to the controller 21.

[0034] The operating lever 24 is operated by the operator and is used to input various operations for operating the lower traveling structure 2, the upper rotating structure 3 and the front working device 6 at an arbitrary speed. When the operating lever 24 is operated by the operator, the operating lever signal SG7 is sent to the hydraulic pump 19 via the operation determination device 25.

[0035] The door lock lever 23 is an input device that is operated by the operator to switch the validity or invalidity of the operating lever signal SG7. The door lock lever 23 allows the supply of working oil to the hydraulic actuator 9 after the operation of setting the operating lever signal SG7 to be valid is input, and stops the supply of working oil to the hydraulic actuator 9 after the operation of setting the operating lever signal SG7 to be invalid is input. In other words, the door lock lever 23 is a locking device that allows or stops (blocks) the supply of working oil to the hydraulic actuator 9. If the door lock lever 23 is operated to a state where the supply of working oil is allowed, the door lock signal SG2 is sent to the controller 21 and the operation determination device 25.

[0036] In addition, the door lock rod 23 may also be such that, according to its operation, the supply path of the working oil from the hydraulic pump 19 to the control valve 20 is connected or cut off, thereby allowing or stopping the supply of the working oil to the hydraulic actuator 9. Alternatively, the door lock rod 23 may also be such that, according to its operation, the transmission path of the operating lever signal SG7 from the operating lever 24 to the hydraulic pump 19 is connected or cut off, thereby allowing or stopping the supply of the working oil to the hydraulic actuator 9.

[0037] The operation permission judgment device 25 allows or stops the transmission of the operating lever signal SG7 from the operating lever 24 to the hydraulic pump 19 based on the door lock signal SG2. If the operation permission judgment device 25 receives the door lock signal SG2, it allows the transmission of the operating lever signal SG7 from the operating lever 24 to the hydraulic pump 19. If the operation permission judgment device 25 does not receive the door lock signal SG2, it stops the transmission of the operating lever signal SG7 from the operating lever 24 to the hydraulic pump 19.

[0038] The controller 21 has a control unit 21a that controls the operation of the working machine 1 in a plurality of different operation modes. The controller 21 also has an operation switching unit 21b that switches the operation mode based on the state of the ignition switch 22, the state of the door lock lever 23, and the supply state of power from the external power source 15. The controller 21 also has a notification unit 21c that causes the notification device 27 to issue an alarm.

[0039] Specifically, the action switching unit 21b of the controller 21 switches the action mode based on the reception status of the ignition signal SG1, the door lock signal SG2, and the external power detection signal SG3. The control unit 21a of the controller 21 sends the power supply availability signals SG4 to SG6 to the converter 17a, the battery 7, and the inverter 17b, respectively, thereby controlling the action of the working machine 1 to an action corresponding to the action mode. Figure 3 The details of the plurality of operation modes of the working machine 1 will be described later. When the operation mode is switched, the notification unit 21c of the controller 21 transmits a notification control signal SG8 to the notification device 27, thereby causing the notification device 27 to issue an alarm.

[0040] The notification device 27 issues an alarm to the operator in the cabin 8 and the workers around the working machine 1 based on the notification control signal SG8 from the notification unit 21c of the controller 21. The notification device 27 emits a sound as an alarm to the operator and the workers around, and displays text and graphics on the display in the cabin 8.

[0041] Figure 3 yes Figure 2 A state transition diagram of an operation mode of the working machine 1 is shown. Figure 4 Yes Description Figure 3 The two-way mode is shown in the figure.

[0042] The plurality of operation modes include a stop mode, a charging mode, a battery drive mode, and a dual-channel mode. The stop mode is an operation mode in which all power supplies are stopped. In the stop mode, the power supply from the external power supply 15 and the battery 7 to the electric motor 18 is stopped, and the power supply from the external power supply 15 to the battery 7 is also stopped. The charging mode is an operation mode in which power is supplied from the external power supply 15 to the battery 7 while the supply of working oil to the hydraulic actuator 9 is stopped. The battery drive mode is an operation mode in which power is supplied from the battery 7 to the electric motor 18 while the power supply from the external power supply 15 to the electric motor 18 is stopped. The dual-channel mode is an operation mode in which power is supplied from the external power supply 15 to the electric motor 18 or from the external power supply 15 and the battery 7 to the electric motor 18.

[0043] like Figure 4 As shown, the dual-path mode makes the power supply method to the electric motor 18 different according to the magnitude relationship between the power W1 to be supplied to the electric motor 18 and the power W2 supplied from the external power supply 15. The controller 21 supplies the power from the external power supply 15 to the electric motor 18 in priority to the power from the battery 7, and charges the battery 7 at the same time.

[0044] Specifically, when the power W1 is greater than the power W2 in the two-way mode, the controller 21 not only supplies the power W2 supplied from the external power source 15 to the electric motor 18, but also discharges the storage battery 7 to supply power to the electric motor 18 in order to compensate for the insufficient power (W1-W2). When the power W1 and the power W2 are almost equal in the two-way mode, the controller 21 supplies the power W2 supplied from the external power source 15 to the electric motor 18. The storage battery 7 is neither discharged nor charged. When the power W1 is less than the power W2 in the two-way mode, the controller 21 not only supplies the power W2 supplied from the external power source 15 to the electric motor 18, but also supplies the remaining power (W2-W1) to the storage battery 7 to charge the storage battery 7. Thus, the working machine 1 can continue to operate even when the power W2 supplied from the external power source 15 is insufficient, and the power supply capacity of the internal power supply source such as the storage battery 7 can be ensured. Thus, the working machine 1 can improve the operation continuity capability regardless of the power supply capacity of the external power source 15.

[0045] The operation switching unit 21b of the controller 21 switches the operation mode to the charging mode, the battery driving mode, the dual mode, or the stop mode based on the reception status of the ignition signal SG1, the door lock signal SG2, and the external power detection signal SG3. Figure 3 In the figure, the case where the controller 21 receives the signals SG1 to SG3 is expressed as on, and the case where the controller 21 does not receive the signals SG1 to SG3 is expressed as off.

[0046] In the stop mode, the ignition signal SG1 is off, the door lock signal SG2 is off, and the external power detection signal SG3 is off. In the stop mode, if the external power detection signal SG3 is turned on while the ignition signal SG1 is off, the action switching unit 21b of the controller 21 switches to the charging mode. In the stop mode, if the ignition signal SG1 is turned on, the action switching unit 21b of the controller 21 starts the working machine 1, and if the door lock signal SG2 is turned on, it switches to the battery drive mode.

[0047] In the charging mode, the ignition signal SG1 is on or off, the door lock signal SG2 is off, and the external power detection signal SG3 is on. In the charging mode, if the ignition signal SG1 becomes on and the door lock signal SG2 becomes on when the external power detection signal SG3 is on, the action switching unit 21b of the controller 21 switches to the dual-path mode. That is, in the charging mode, if the ignition switch 22 is set to a state that allows power supply to the electric motor 18 and the door lock rod 23 is set to a state that allows the supply of working oil when the external power detection device 26 detects power supply from the external power supply 15, the action switching unit 21b of the controller 21 switches to the dual-path mode. In the charging mode, if the external power detection signal SG3 becomes off when the ignition signal SG1 is off, the action switching unit 21b of the controller 21 switches to the stop mode regardless of the door lock signal SG2.

[0048] In the dual-channel mode, the ignition signal SG1 is on, the door lock signal SG2 is on, and the external power detection signal SG3 is on. In the dual-channel mode, if the door lock signal SG2 becomes off when the external power detection signal SG3 is on, the action switching unit 21b of the controller 21 switches to the charging mode regardless of the ignition signal SG1. That is, in the dual-channel mode, if the door lock rod 23 is set to stop the supply of working oil when the external power detection device 26 detects the power supply from the external power supply 15, the action switching unit 21b of the controller 21 switches to the charging mode. In the dual-channel mode, if the external power detection signal SG3 becomes off when the ignition signal SG1 is on and the door lock signal SG2 is on, the action switching unit 21b of the controller 21 switches to the battery drive mode. That is, in the dual-path mode, if the ignition switch 22 is in a state of allowing power supply to the electric motor 18 and the door lock rod 23 is in a state of allowing the supply of working oil, and the external power detection device 26 is in a state of not detecting power supply from the external power supply 15, the action switching unit 21b of the controller 21 switches to the battery drive mode. In the dual-path mode, if the ignition signal SG1 is turned off and the external power detection signal SG3 is turned off, the action switching unit 21b of the controller 21 switches to the stop mode regardless of the door lock signal SG2.

[0049] In the battery drive mode, the ignition signal SG1 is on, the door lock signal SG2 is on, and the external power detection signal SG3 is off. In the battery drive mode, if the ignition signal SG1 is turned off while the external power detection signal SG3 is off, the action switching unit 21b of the controller 21 switches to the stop mode regardless of the door lock signal SG2.

[0050] The notification unit 21c of the controller 21 causes the notification device 27 to issue an alarm when switching from the stop mode to the charging mode and when switching from the charging mode to the dual-channel mode. Furthermore, when switching from the dual-channel mode to the battery drive mode, the notification unit 21c of the controller 21 causes the notification device 27 to issue an alarm in a different manner from the alarms in the switching from the stop mode to the charging mode and in the switching from the charging mode to the dual-channel mode.

[0051] Figure 5 Yes means switching Figure 3 A timing chart showing an example of operation of the working machine in the operation mode shown. Figure 5 An operation example of the working machine 1 switching from the stop mode to the stop mode via the charging mode, the two-way mode, and the battery drive mode in sequence is shown.

[0052] Figure 5 as well as Figure 6 In FIG. 1 , the converter output current indicates the current supplied from the converter 17a to each device (at least one of the battery 7 and the inverter 17b). The inverter output current indicates the current supplied from the inverter 17b to the electric motor 18.

[0053] At time t1, when the operator turns on the inverter 17a and the external power supply 15 of the working machine 1 through the power supply cable 16, the external power detection signal SG3, and the controller 21 switches the operation mode from the stop mode to the charging mode. If the charging mode is switched, the inverter output current flows, and the battery 7 is supplied with power to charge the battery 7.

[0054] At time t2, when the operator operates the ignition switch 22 to turn on the ignition signal SG1 and operates the door lock lever 23 to turn on the door lock signal SG2, the controller 21 switches the operation mode from the charging mode to the two-way mode. When switching to the two-way mode, the inverter output current flows to supply power to the electric motor 18.

[0055] At time t3, when the operator operates the door lock lever 23 to turn off the door lock signal SG2, the controller 21 switches the operation mode from the two-way mode to the charging mode. When switching to the charging mode, the inverter output current stops flowing, and the power supply to the electric motor 18 stops.

[0056] At time t4 , when the operator operates the door lock lever 23 and the door lock signal SG2 turns on, the controller 21 switches the operation mode from the charging mode to the two-way mode. When the two-way mode is switched, the inverter output current flows and the electric motor 18 is supplied with electric power.

[0057] At time t5, when the power supply cable 16 is disconnected from the external power supply 15 or the converter 17a and the external power detection signal SG3 is turned off, the controller 21 switches from the dual-path mode to the battery drive mode. If switched to the battery drive mode, the converter output current no longer flows, and the battery 7 discharges and supplies power to the inverter 17b.

[0058] At time t6, when the operator operates the door lock lever 23 to turn off the door lock signal SG2 and operates the ignition switch 22 to turn off the ignition signal SG1, the controller 21 switches the operation mode from the battery drive mode to the stop mode. If the mode is switched to the stop mode, the converter output current and the inverter output current no longer flow, and the charging and discharging of the battery 7 stops.

[0059] Figure 6 Yes means switching Figure 3 A timing chart of another operation example of the working machine in the operation mode shown. Figure 6 An operation example of switching the working machine 1 from the stop mode to the stop mode via the battery drive mode is shown.

[0060] At time t11, when the operator operates the ignition switch 22 to turn on the ignition signal SG1 and operates the door lock lever 23 to turn on the door lock signal SG2, the controller 21 switches the operation mode from the stop mode to the battery drive mode. If the mode is switched to the battery drive mode, the battery 7 is discharged to supply power to the inverter 17b. The inverter output current flows to supply power to the electric motor 18.

[0061] At time t12, when the operator operates the door lock lever 23 to turn off the door lock signal SG2 and operates the ignition switch 22 to turn on the ignition signal SG1, the controller 21 switches the operation mode from the battery drive mode to the stop mode. If the stop mode is switched, the converter output current and the inverter output current no longer flow, and the charging and discharging of the battery 7 stops.

[0062] As described above, the working machine 1 of the present embodiment is an electric working machine that uses the electric power supplied from the external power supply 15 as a power source. The working machine 1 has an electric motor 18 that drives the hydraulic pump 19 that supplies working oil to the hydraulic actuator 9. The working machine 1 has an ignition switch 22 that allows or stops the supply of electric power to the electric motor 18, and a door lock rod 23 that is a locking device that allows or stops the supply of working oil to the hydraulic actuator 9. The working machine 1 has a controller 21 that controls the operation of the working machine 1. The controller 21 switches the operation mode of the working machine 1 based on the state of the ignition switch 22, the state of the door lock rod 23, and the supply state of electric power from the external power supply 15.

[0063] Therefore, the working machine 1 of this embodiment can automatically switch the action mode only by the operator operating the ignition switch 22 and the door lock rod 23, etc., which are standardly equipped on the working machine 1. In other words, the working machine 1 of this embodiment does not need to be provided with a dedicated input device for switching the action mode, and the action mode can be automatically switched even if the operator does not perform a dedicated input operation on the input device. Therefore, the working machine 1 of this embodiment can save the effort of operating the dedicated input device for switching the action mode. Therefore, according to this embodiment, an electric working machine that does not require the operator to consciously switch the action mode and has excellent operability can be provided.

[0064] Moreover, the working machine 1 of the present embodiment further comprises: a battery 7 provided inside; and an external power detection device 26 for detecting the power supply from the external power supply 15. The operation modes include: a charging mode in which power is supplied from the external power supply 15 to the battery 7 in a state in which the supply of the working oil to the hydraulic actuator 9 is stopped; and a battery drive mode in which power is supplied from the battery 7 to the electric motor 18 in a state in which the power supply from the external power supply 15 to the electric motor 18 is stopped. The operation modes include a two-way mode in which power is supplied from the external power supply 15 to the electric motor 18 or power is supplied from the external power supply 15 and the battery 7 to the electric motor 18. The controller 21 switches the operation mode to the charging mode, the battery drive mode, or the two-way mode based on the states of the ignition switch 22, the door lock rod 23, and the external power detection device 26.

[0065] Thus, the working machine 1 of this embodiment can switch the operation mode to the charging mode, the battery drive mode, or the dual-channel mode only by the operator operating the ignition switch 22 and the door lock rod 23, etc., which are standardly equipped on the working machine 1. Therefore, the working machine 1 of this embodiment can switch to an operation mode suitable for the power supply method from the power supply source such as the battery 7 and the external power supply 15 without preparing a dedicated input device and a dedicated operation. Therefore, according to this embodiment, it is possible to provide an electric working machine that does not require the operator to consciously switch the operation mode appropriately and has better operability.

[0066] Furthermore, in the charging mode, the working machine 1 of the present embodiment switches to the dual-path mode when the ignition switch 22 is set to a state in which power supply to the electric motor 18 is permitted and the door lock lever 23 is set to a state in which supply of the operating oil is permitted while the external power detection device 26 detects power supply from the external power source 15. In the dual-path mode, when the door lock lever 23 is set to a state in which supply of the operating oil is stopped while the external power detection device 26 detects power supply from the external power source 15, the controller 21 switches to the charging mode.

[0067] That is, the working machine 1 of the present embodiment can switch from the charging mode to the two-way mode only by the operator's standardized operation of the ignition switch 22 and the door lock rod 23 that are standardly equipped on the working machine 1. Moreover, the working machine 1 of the present embodiment can switch from the two-way mode to the charging mode even if the ignition switch 22 is not operated to stop the power supply to the electric motor 18. Therefore, the working machine 1 of the present embodiment can switch from the two-way mode to the charging mode without transferring the working machine 1 to the action stop state, so the switch from the two-way mode to the charging mode can be performed quickly. As a result, it is possible to provide an electric working machine that does not require the operator to consciously switch the action mode quickly and has better operability.

[0068] Moreover, in the dual-circuit mode of the working machine 1 of this embodiment, if the ignition switch 22 is in a state allowing power supply to the electric motor 18, and the door lock rod 23 is in a state allowing the supply of working oil, the external power detection device 26 is in a state where the power supply from the external power supply 15 is not detected, then the controller 21 switches to the battery drive mode.

[0069] Thus, even if the power supply cable 16 is accidentally disconnected or a power outage occurs, causing the power supply from the external power source 15 to stop unexpectedly, the working machine 1 of this embodiment can immediately switch to the battery drive mode without switching to the stop mode and continue the operation of the working machine 1. Therefore, the working machine 1 of this embodiment can prevent the working machine 1 from stopping suddenly, and thus can prevent accidents such as the overturning of the working machine 1. Therefore, according to this embodiment, it is possible to provide an electric working machine that does not require the operator to consciously switch the operation mode safely and has better operability.

[0070] The working machine 1 of this embodiment further includes a notification device 27 for sounding an alarm. The plurality of operation modes further include a stop mode for stopping all power supplies. The controller 21 causes the notification device 27 to sound an alarm when switching from the stop mode to the charging mode and when switching from the charging mode to the dual-channel mode.

[0071] Thus, the working machine 1 of this embodiment can notify the operator and the surrounding workers that the state of stopping the power supply to the electric motor 18 is shifted to the state of allowing the power supply to the electric motor 18, thereby calling their attention. Thus, according to this embodiment, it is possible to provide an electric working machine that does not require the operator to consciously switch the operation mode safely and has better operability.

[0072] Furthermore, in the working machine 1 of the present embodiment, when switching from the dual mode to the battery drive mode, the controller 21 causes the alarm device 27 to issue an alarm in a different alarm method from when switching from the stop mode to the charging mode and when switching from the charging mode to the dual mode.

[0073] Thus, the working machine 1 of this embodiment can notify the operator and surrounding workers that the power supply from the external power source 15 has stopped unexpectedly, and call their attention. Thus, according to this embodiment, it is possible to provide an electric working machine that does not require the operator to consciously switch the operation mode safely and has better operability.

[0074] Figure 7 It is a diagram for explaining a modified example of the external power detection device 26 .

[0075] Figure 2 The external power detection device 26 shown is constituted by a sensor built in the converter 17a, and detects the power supplied from the external power source 15. However, the external power detection device 26 is not limited to this.

[0076] For example, the external power detection device 26 may detect the connection state of the power supply cable 16 connecting the external power supply 15 and the working machine 1. Furthermore, the external power detection device 26 may send the external power detection signal SG3 to the controller 21 when the power supply cable 16 is in a state of connecting the external power supply 15 and the working machine 1.

[0077] For example, Figure 7 As shown, a circuit breaker 29 may be provided on a power supply path 28 in the working machine 1 between the external power supply 15 and the storage battery 7. The circuit breaker 29 is provided between the external power supply 15 and the converter 17a, and cuts off the power supply from the external power supply 15 when the converter 17a fails. The circuit breaker 29 operates according to the power supply availability signal SG4 from the control unit 21a of the controller 21. The external power detection device 26 may also detect the operating state of the circuit breaker 29. Furthermore, the external power detection device 26 may also be configured to send an external power detection signal SG3 to the controller 21 if the circuit breaker 29 is in a state where the power supply from the external power supply 15 is not cut off.

[0078] The external power source 15 may be a power supply source that supplies DC power. In this case, the converter 17a is composed of a DC-DC converter, and converts the DC power supplied from the external power source 15 into DC power that can be used by the battery 7 and the inverter 17b.

[0079] In this way, the external power detection device 26 of this embodiment can detect the power supply from the external power supply 15 based on at least one of the detection results of the sensor that detects the power supplied from the external power supply 15, the connection status of the power supply cable 16 connecting the external power supply 15 and the working machine 1, and the working status of the circuit breaker 29 provided on the power supply path 28 between the external power supply 15 and the battery 7.

[0080] Thus, the external power detection device 26 of the present embodiment can detect the power supply from various external power sources 15. Therefore, the working machine 1 of the present embodiment can switch the operation mode without preparing a dedicated input device and a dedicated operation in accordance with various models of the working machine 1. Therefore, according to the present embodiment, it is possible to provide an electric working machine that does not require the operator to consciously switch the operation mode and has excellent operability and versatility.

[0081] The embodiments of the present invention are described in detail above, but the present invention is not limited to the above-mentioned embodiments, and various changes can be made within the scope of the spirit of the present invention described in the technical solution. The present invention can add the structure of a certain embodiment to the structure of other embodiments, or replace the structure of a certain embodiment with other embodiments, or delete a part of the structure of a certain embodiment.

[0082] Description of Reference Numerals

[0083] 1 ... operating machine, 7 ... battery, 9 ... hydraulic actuator, 15 ... external power source, 16 ... power supply cable, 18 ... electric motor, 19 ... hydraulic pump, 21 ... controller, 22 ... ignition switch, 23 ... door lock lever (locking device), 26 ... external power detection device, 27 ... alarm device, 28 ... power supply path, 29 ... circuit breaker.

Claims

1. A working machine, which is an electric working machine that uses electric power supplied from an external power source as a power source, characterized in that: The working machine has: an electric motor that drives a hydraulic pump that supplies working oil to a hydraulic actuator; an ignition switch that allows or stops the supply of power to the electric motor; a locking device that allows or stops the supply of the working oil to the hydraulic actuator; and a controller for controlling the operation of the working machine, The controller switches an operation mode of the working machine based on a state of the ignition switch, a state of the locking device, and a supply state of electric power from the external power supply.

2. The working machine according to claim 1, characterized in that: Further having: Internally located storage battery; and external power detection means for detecting power supply from the external power source, The action modes include: a charging mode in which electric power is supplied from the external power supply to the battery while supply of the hydraulic oil to the hydraulic actuator is stopped; a battery drive mode in which power is supplied from the battery to the electric motor in a state where power supply from the external power source to the electric motor is stopped; and a dual-path mode in which power is supplied from the external power supply to the electric motor or from the external power supply and the battery to the electric motor, The controller switches the operation mode to the charging mode, the battery driving mode, or the two-way mode based on the states of the ignition switch, the locking device, and the external power detection device.

3. The working machine according to claim 2, characterized in that: The controller is configured as follows: In the charging mode, if the external power detection device detects the power supply from the external power source, the ignition switch is set to a state of allowing the power supply to the electric motor, and the locking device is set to a state of allowing the supply of the working oil, the two-way mode is switched to. In the two-way mode, if the locking device is in a state of stopping the supply of the hydraulic oil while the external power detection device detects the supply of power from the external power source, the mode is switched to the charging mode.

4. The working machine according to claim 2, characterized in that: In the dual-path mode, if the ignition switch is in a state allowing power supply to the electric motor, and the locking device is in a state allowing the supply of the working oil, and the external power detection device is in a state where power supply from the external power supply is not detected, the controller switches to the battery drive mode.

5. The working machine according to claim 2, characterized in that: It further has a notification device for issuing an alarm, The operation mode further includes a stop mode in which all power supplies are stopped. The controller causes the notification device to issue the alarm when switching from the stop mode to the charging mode and when switching from the charging mode to the two-way mode.

6. The working machine according to claim 5, characterized in that: When switching from the two-way mode to the battery drive mode, the controller causes the notification device to issue the alarm in a notification method different from that when switching from the stop mode to the charging mode and when switching from the charging mode to the two-way mode.

7. The working machine according to claim 1, characterized in that: Further possesses: Internally located storage batteries; and external power detection means for detecting power supply from the external power source, The external power detection device detects the power supply from the external power supply based on at least one of the detection result of the sensor that detects the power supplied from the external power supply, the connection state of the power supply cable connecting the external power supply and the working machine, and the working state of the circuit breaker provided on the power supply path between the external power supply and the battery.

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