Control method of work machine

Abstract

To provide a control method of a work machine making operators and like recognize start of an electric motor only when the electric motor is allowed to start.SOLUTION: A control method of a work machine provided with a cut-off lever operated in an unstartable state or a startable state of a machine body upon operating with an electric motor, includes displaying a first display on a display when the electric motor is in the startable state in response of a start instruction of the electric motor in a state the machine body is in the unstartable state.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a control method for a working machine.

Background Art

[0002] Conventionally, an electric excavator has been disclosed that detects the rotational position of a key by a key switch and starts an electric motor when the key is rotated to the starting position (start position) of the electric motor (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An electric excavator driven by an electric motor is quieter in driving noise than an excavator driven by an engine. For this reason, an operator and workers around the electric excavator (hereinafter also referred to as "operator etc.") may not notice the start of the electric motor when the electric motor starts, which is dangerous. Therefore, when the electric motor starts, it is necessary to make the operator etc. recognize the start of the electric motor by some method.

[0005] For example, when the cutoff switch is on because the cutoff lever has been rotated to the lower position, depending on the operating state of the electric excavator, there are cases where the electric motor cannot be started in order to ensure safety. In this case, even if a start instruction for the electric motor is detected by the key switch, the electric motor will not start, so it is not necessary to make the operator or the like recognize the start of the electric motor. Therefore, it is desirable to make the operator or the like recognize the start of the electric motor only when the electric motor can be started. However, an electric excavator having such an effect has not yet been proposed, including Patent Document 1.

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a control method for a working machine that can make an operator or the like recognize the start of an electric motor only when the electric motor can be started.

Means for Solving the Problems

[0007] A control method for a working machine according to one aspect of the present invention is a control method for a working machine including a cutoff lever that is driven by an electric motor and operates the machine body between a non-drivable state and a drivable state, and based on a start instruction for the electric motor in the non-drivable state of the machine body, when the electric motor is in a drivable state, displaying a first screen on a display unit.

Effects of the Invention

[0008] According to the above configuration, it is possible to make an operator or the like recognize the start of the electric motor only when the electric motor can be started.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] The embodiments of the present invention will be described as follows with reference to the drawings.

[0011] 〔1. Electric Working Machine〕 FIG. 1 is a side view showing a schematic configuration of a hydraulic excavator 1 that constitutes an electric excavator, which is an example of the electric working machine of the present embodiment. The hydraulic excavator 1 includes a lower traveling body 2, a working machine 3, and an upper swing body 4.

[0012] Here, in FIG. 1, the directions are defined as follows. First, the direction in which the lower traveling body 2 travels straight is defined as the front-rear direction, and one side thereof is defined as "front" and the other side is defined as "rear". In FIG. 1, as an example, the side of the travel motor 22 with respect to the blade 23 is shown as "front". Also, the lateral direction perpendicular to the front-rear direction is defined as the left-right direction. At this time, when viewed from the operator (operator, driver) sitting in the operator's seat 41a, the left side is defined as "left" and the right side is defined as "right". Further, the gravitational direction perpendicular to the front-rear direction and the left-right direction is defined as the up-down direction, the upstream side in the gravitational direction is defined as "up", and the downstream side is defined as "down".

[0013] The lower traveling body 2 includes a pair of left and right crawlers 21 and a pair of left and right traveling motors 22. Each traveling motor 22 is a hydraulic motor. By driving the left and right crawlers 21 with the left and right traveling motors 22 respectively, the hydraulic excavator 1 can be moved forward and backward. The lower traveling body 2 is provided with a blade 23 for leveling work and a blade cylinder 23a. The blade cylinder 23a is a hydraulic cylinder that rotates the blade 23 in the vertical direction.

[0014] The working machine 3 includes a boom 31, an arm 32, and a bucket 33. By driving the boom 31, the arm 32, and the bucket 33 independently, excavation work such as earth and sand can be performed.

[0015] The boom 31 is rotated by a boom cylinder 31a. The base end of the boom cylinder 31a is supported by the front part of the upper swing body 4 and is movable in a telescopic manner. The arm 32 is rotated by an arm cylinder 32a. The base end of the arm cylinder 32a is supported by the tip of the boom 31 and is movable in a telescopic manner. The bucket 33 is rotated by a bucket cylinder 33a. The base end of the bucket cylinder 33a is supported by the tip of the arm 32 and is movable in a telescopic manner. The boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a are constituted by hydraulic cylinders.

[0016] The upper swing body 4 is configured to be swingable with respect to the lower traveling body 2 via a swing bearing (not shown). The upper swing body 4 is provided with a cab 41, a swing platform 42, a swing motor 43, an engine room 44, etc. The upper swing body 4 swings via the swing bearing by driving the swing motor 43 which is a hydraulic motor.

[0017] A plurality of hydraulic pumps 71 (see FIG. 2) are arranged in the upper swing body 4. Each hydraulic pump 71 is driven by an electric motor 61 (see FIG. 2) inside the engine room 44. Each hydraulic pump 71 supplies hydraulic oil (pressure oil) to hydraulic motors (for example, left and right traveling motors 22, swing motor 43) and hydraulic cylinders (for example, blade cylinder 23a, boom cylinder 31a, arm cylinder 32a, bucket cylinder 33a). The hydraulic motors and hydraulic cylinders driven by the supply of hydraulic oil from an arbitrary hydraulic pump 71 are collectively called a hydraulic actuator 73 (see FIG. 2).

[0018] A driver's seat 41a is arranged in the control unit 41. Various levers 41b are arranged around the driver's seat 41a. When the operator sits on the driver's seat 41a and operates the lever 41b, the hydraulic actuator 73 is driven. Thereby, the traveling of the lower traveling body 2, the leveling work by the blade 23, the excavation work by the work implement 3, the swing of the upper swing body 4, etc. can be performed.

[0019] In particular, the lever 41b includes an operation lever 41b1 for driving the hydraulic actuator 73 and a cut-off lever 41b2. The cut-off lever 41b2 is provided so as to be rotatable up and down on the left side of the driver's seat 41a. The rotation position of the cut-off lever 41b2 is detected by a cut-off switch 41c (see FIG. 2). The cut-off switch 41c is arranged at the base end portion of the cut-off lever 41b2.

[0020] When the operator depresses the cut-off lever 41b2, the cut-off switch 41c turns on, and in conjunction therewith, a solenoid valve 76 (see FIG. 2), which will be described later, becomes energized. As a result, the operator can operate a predetermined operation lever 41b1 to drive a predetermined hydraulic actuator 73. On the other hand, when the operator pulls up the cut-off lever 41b2, the cut-off switch 41c turns off, and in conjunction therewith, the solenoid valve 76 becomes de-energized and is shut off. In this case, even if the operator operates the operation lever 41b1, the hydraulic actuator 73 cannot be driven. From this, it can be said that the cut-off switch 41c (or the cut-off lever 41b2) constitutes a drive control unit 90 that regulates the drive of the hydraulic excavator 1. That is, the hydraulic excavator 1 includes a drive control unit 90 (for example, the cut-off switch 41c) that regulates the drive of the hydraulic excavator 1. When the operator tries to get off the control unit 41, the operator pulls up the cut-off lever 41b2 to disable the drive of the hydraulic actuator 73 and then gets off the operator's seat 41a.

[0021] A first battery 53 is attached to the upper swing body 4. The first battery 53 is composed of, for example, a lithium-ion battery and outputs a higher voltage than a second battery 54 (see FIG. 2), which will be described later. The electric motor 61 can be driven by the electric power supplied from the first battery 53. In addition, a power supply port (not shown) is provided in the upper swing body 4. The power supply port and the external power supply 51 are connected via a power supply cable 52. Thereby, it is also possible to charge the first battery 53.

[0022] When the lower traveling body 2, the working machine 3, and the upper swing body 4 are collectively referred to as the machine body BA, the machine body BA may be driven by using both equipment driven by electric power and hydraulic equipment. That is, in addition to hydraulic equipment such as the hydraulic actuator 73, the machine body BA may include an electric traveling motor, an electric cylinder, an electric swing motor, and the like. Further, the machine body BA may be driven only by electric power without using hydraulic equipment (all-electric).

[0023] 〔2. Configuration of Control System and Hydraulic System〕 Figure 2 is a block diagram schematically showing the configuration of the control system and the hydraulic system of the hydraulic excavator 1. In Figure 2, the arrow indicated by the broken line indicates the transmission path of the detection signal. The hydraulic excavator 1 includes an electric motor 61. The electric motor 61 is driven by the electric power supplied from at least one of an external power source 51 (see Figure 1) and a first battery 53 via an inverter 63 described later.

[0024] The hydraulic excavator 1 includes a power supply 62, an inverter 63, a converter 64, and a drive switch 65.

[0025] The power supply 62 converts the AC voltage supplied from the external power source 51 via the power supply cable 52 (see Figure 1) into a DC voltage. The DC voltage (electric power) output from the power supply 62 is supplied to the inverter 63 or the first battery 53. When power is supplied from the external power source 51 to the first battery 53 via the power supply 62, the first battery 53 is charged. That is, the hydraulic excavator 1 includes a power supply 62 that supplies the electric power supplied from the external power source 51 to the first battery 53.

[0026] The inverter 63 converts the DC voltage output from the power supply 62 or the DC voltage supplied from the first battery 53 into an AC voltage and supplies it to the electric motor 61. Thereby, the electric motor 61 rotates. The supply of the AC voltage (current) from the inverter 63 to the electric motor 61 is performed based on a rotation command (control signal) output from an ECU 80 described later.

[0027] The converter 64 converts the high-voltage (for example, 300V) DC voltage supplied from the power supply 62 or the first battery 53 into a low-voltage (for example, 12V) DC voltage. The converter 64 supplies electric power to, for example, a pump (not shown) that circulates the cooling water for cooling the electric motor 61.

[0028] The drive switch 65 is a key switch that detects the rotational position of a key inserted into the key cylinder by the operator. Information on the rotational position of the key detected by the drive switch 65 is output to the ECU 80. Power is supplied to the drive switch 65 and the ECU 80 from the second battery 54. The second battery 54 is composed of, for example, a lead battery that outputs a low voltage of 12V.

[0029] Here, as the rotational positions of the key detected by the drive switch 65, there are a first position, a second position, and a third position. The first position is a position (on position) that supplies power from the second battery 54 to the ECU 80 and electrical components. The second position is a position (start position) that starts the electric motor 61. The third position is a position (off position) that cuts off the power supply to the ECU 80 and stops the electric motor 61. When the operator rotates the key in the order of the third position, the first position, and the second position, the electric motor 61 starts. After the electric motor 61 starts, the key is returned from the second position to the first position. When the operator rotates the key from the first position to the third position, the electric motor 61 stops.

[0030] Note that in this embodiment, the drive switch 65 detects an instruction to start or stop the electric motor 61 by the operator by detecting the rotational position of the key, but it may also be configured to detect an instruction to start or stop the electric motor 61 by the operator by detecting the number of presses or the pressing time of a push button. For example, when the operator long-presses the button while the cut-off lever 41b2 is in the raised state, an instruction to start the electric motor 61 by the operator may be detected, and then, when the operator short-presses the button, an instruction to stop the electric motor 61 may be detected.

[0031] As described above, the hydraulic excavator 1 of this embodiment includes a drive switch 65 that detects an instruction to start or stop the electric motor 61 (according to the rotation of the key or the pressing operation of the button).

[0032] In addition, the hydraulic excavator 1 is provided with a notification unit 66. The notification unit 66 notifies of the start of the electric motor 61. Such a notification unit 66 includes an alarm sound output unit 66a and a visual information presentation unit 66b. The alarm sound output unit 66a is composed of, for example, a buzzer and outputs an alarm sound (buzzer sound).

[0033] The visual information presentation unit 66b presents visual information regarding the start of the electric motor 61. Such a visual information presentation unit 66b includes a warning light 66b1. The warning light 66b1 is composed of, for example, a rotating lamp (rotating light), but may also be composed of a lamp that only lights up or blinks without rotating. As shown in FIG. 1, the warning light 66b1 is installed, for example, on a frame that supports the top surface of the operator's seat 41a, but the installation position of the warning light 66b1 is not particularly limited.

[0034] In addition, the visual information presentation unit 66b further includes a display unit 66b2. That is, the notification unit 66 includes the display unit 66b2. The display unit 66b2 is composed of, for example, a liquid crystal display device and displays a screen (see FIG. 4) indicating that the electric motor 61 has been started. Such a display unit 66b2 is installed, for example, beside the operator's seat 41a.

[0035] Information regarding the start of the electric motor 61 can be visually presented to the operator or surrounding workers by the lighting (blinking) of the warning light 66b1 or the screen display on the display unit 66b2. That is, the above-mentioned visual information presented by the visual information presentation unit 66b includes optical information by the lighting (blinking) of the warning light 66b1 and display information of the display unit 66b2. Note that the information regarding the start of the electric motor 61 includes at least one of information indicating that the electric motor 61 has already been started and information indicating that the electric motor 61 will be started (advance notice of start).

[0036] In this way, the notification unit 66 includes an alarm sound output unit 66a that outputs an alarm sound. In addition, the notification unit 66 includes a visual information presentation unit 66b that presents visual information regarding the start of the electric motor 61.

[0037] In addition, the hydraulic excavator 1 is provided with a charging mode setting switch 67. The charging mode setting switch 67 is installed, for example, beside the operator's seat 41a and is pressed when the operator sets the charging mode. The charging mode is a mode in which the electric power supplied from the external power source 51 is supplied to the first battery 53 via the power feeder 62 to charge the first battery 53. The charging mode setting switch 67 functions as a charging mode setting detection unit that detects whether the drive mode of the hydraulic excavator 1 is set to the charging mode for charging the first battery 53 as an operating state of the hydraulic excavator 1.

[0038] A pilot pump 70 and a plurality of hydraulic pumps 71 are connected to the rotating shaft (output shaft) of the above-described electric motor 61. The pilot pump 70 discharges pilot oil that serves as an input command to the control valve 72. The control valve 72 is a direction switching valve that controls the flow direction and flow rate of the pressure oil supplied from the hydraulic pump 71 to the hydraulic actuator 73, and is provided corresponding to each hydraulic actuator 73.

[0039] The plurality of hydraulic pumps 71 include a variable displacement pump and a fixed displacement pump. In FIG. 2, only one hydraulic pump 71 is illustrated as an example. The hydraulic pump 71 supplies the hydraulic oil in the hydraulic oil tank (not shown) as pressure oil to the hydraulic actuator 73 via the control valve 72. Thereby, the hydraulic actuator 73 is driven.

[0040] The hydraulic excavator 1 further includes a remote control valve 75 and a solenoid valve 76. The remote control valve 75 is provided to switch the direction and pressure of the pilot oil supplied from the pilot pump 70 to the control valve 72. The remote control valve 75 constitutes the operation lever 41b1 and generates a pilot secondary pressure by reducing the pressure (pilot pressure) of the pilot oil supplied from the pilot pump 70 according to the operation direction and operation amount of the operation lever 41b1.

[0041] The solenoid valve 76 is located in the oil passage between the pilot pump 70 and the remote control valve 75, and controls the supply of pilot oil (pilot pressure) from the pilot pump 70 to the remote control valve 75.

[0042] The hydraulic excavator 1 further includes an ECU (Electronic Control Unit). The ECU 80 is a controller that controls each part of the hydraulic excavator 1, and is configured to include, for example, a CPU (Central Processing Unit), a storage unit, etc. In particular, the ECU 80 has a determination unit 80a and a notification control unit 80b in addition to a main control unit (not shown) that generates a rotation command for the electric motor 61 and supplies it to the inverter 63.

[0043] The determination unit 80a determines whether the electric motor 61 can be started based on the operating state of the hydraulic excavator 1. Here, as the operating state of the hydraulic excavator 1, for example, there is a detection state (on or off) of the cut-off switch 41c.

[0044] The notification control unit 80b controls the notification unit 66 based on the determination result of the determination unit 80a. That is, the notification control unit 80b controls the alarm sound output unit 66a and the visual information presentation unit 66b based on the determination result of the determination unit 80a.

[0045] Note that the hydraulic excavator 1 of the present embodiment may be provided with an abnormality detection unit 91, but the details of the abnormality detection unit 91 will be described later. Hereinafter, the details of the notification control in the ECU 80 will be described.

[0046] 〔3. Details of Notification Control〕 FIG. 3 is a flowchart showing the operation flow when the ECU 80 controls the notification unit 66. First, when the drive switch 65 detects a start instruction for the electric motor 61 based on the operator's key operation or button pressing operation (Yes in S1), the determination unit 80a of the ECU 80 determines whether the electric motor 61 can be started based on the operating state of the hydraulic excavator 1 (S2).

[0047] For example, when the cut-off switch 41c is off, that is, when the drive control unit 90 is regulating the drive of the hydraulic excavator 1, the determination unit 80a determines that the electric motor 61 can be started. On the other hand, when the cut-off switch 41c is on, that is, when the drive control unit 90 releases the regulation of the drive of the hydraulic excavator 1, the determination unit 80a determines that the electric motor 61 cannot be started.

[0048] When it is determined that the electric motor 61 cannot be started (No in S3), the notification control unit 80b ends the notification control without causing the notification unit 66 to execute a notification regarding the start of the electric motor 61. On the other hand, when it is determined that the electric motor 61 can be started (Yes in S3), the notification control unit 80b causes the notification unit 66 to execute a notification regarding the start of the electric motor 61 (S4). For example, the notification control unit 80b causes the buzzer sound output unit 66a to output a buzzer sound, or causes the warning lamp 66b1 of the visual information presentation unit 66b to light up (or blink). Note that the notification control unit 80b may cause the buzzer sound output unit 66a to output a buzzer sound and at the same time cause the warning lamp 66b1 to light up (or blink).

[0049] FIG. 4 schematically shows an example of the display screen of the display unit 66b2 of the visual information presentation unit 66b. In S4, the notification control unit 80b may display visual information (the character 'READY' in the example of the figure) indicating that the electric motor 61 can be started on the display screen of the display unit 66b2. Note that the display of the visual information on the display unit 66b2 may be performed simultaneously with or independently of at least one of the output of the warning sound from the warning sound output unit 66a and the lighting of the warning lamp 66b1.

[0050] When a predetermined time has elapsed after the notification by the notification unit 66 is executed, the notification control unit 80b ends the execution of the notification by the notification unit 66 and ends a series of notification controls.

[0051] In addition, when the electric motor 61 can be started, at S1, after the drive switch 65 detects an instruction to start the electric motor 61, the timing at which the electric motor 61 is actually started may be before or after the notification by the notification unit 66. In the former case, the fact that the electric motor 61 has been started can be notified to the operator or the like by the notification unit 66. On the other hand, in the latter case, the notification by the notification unit 66 informs the operator or the like that the electric motor 61 is about to be started, that is, it is a notice about the start of the electric motor 61.

[0052] In this way, when the drive switch 65 detects an instruction to start the electric motor 61 (Yes at S1) and when the determination unit 80a determines that the electric motor 61 can be started (Yes at S3), the notification control unit 80b causes the notification unit 66 to execute a notification (about the start of the electric motor 61) (S4).

[0053] According to the above control, since the driving sound of the electric motor 61 is silent, even when it is difficult for the operator or the like to notice the driving sound of the electric motor 61, the start of the electric motor 61 can be recognized by the operator or the like through the notification of the notification unit 66. As a result, the operator or the like can perceive that the electric motor 61 has been started and there is a possibility that the hydraulic excavator 1 will operate, and can take actions to avoid danger. Also, depending on the operating state of the hydraulic excavator 1 (for example, when the cut-off switch 41c is on), there is a state where the electric motor 61 cannot be started. However, the determination unit 80a determines whether the electric motor 61 can be started based on the operating state of the hydraulic excavator 1, and when it is determined that the start is possible, the notification unit 66 executes the notification. Thereby, only when the electric motor 61 can be started, the notification unit 66 can be made to execute the notification, and the start of the electric motor 61 can be recognized by the operator or the like. That is, even if the drive switch 65 detects an instruction to start the electric motor 61, when the electric motor 61 cannot be started, since the electric motor 61 is not started, unnecessary notifications by the notification unit 66 about the start of the electric motor 61 can be eliminated.

[0054] Also, in S2, the determination unit 80a determines that the electric motor 61 cannot be started when the drive control unit 90 (cut-off switch 41c) releases the drive regulation of the hydraulic excavator 1 as the operating state of the hydraulic excavator 1.

[0055] When the drive regulation of the hydraulic excavator 1 is released and the electric motor 61 is started, the hydraulic excavator 1 (for example, the hydraulic actuator 73) may start moving immediately in response to the operation of the operation lever 41b1, which is dangerous. For this reason, when the drive regulation of the hydraulic excavator 1 is released, even if the drive switch 65 detects an instruction to start the electric motor 61, the ECU 80 executes control not to start the electric motor 61 (starting restraint function). In this case, since the electric motor 61 is not started, it is not necessary to execute the notification by the notification unit 66 regarding the start of the electric motor 61. Therefore, when the drive regulation of the hydraulic excavator 1 is released, by determining that the electric motor 61 cannot be started by the determination unit 80a, it is possible to prevent the notification unit 66 from executing the notification and eliminate unnecessary notifications by the notification unit 66.

[0056] Also, in S2, the determination unit 80a determines that the electric motor 61 can be started when the drive control unit 90 (cut-off switch 41c) regulates the drive of the hydraulic excavator 1 as the operating state of the hydraulic excavator 1.

[0057] When the drive of the hydraulic excavator 1 is regulated, even if the electric motor 61 is started and the operation lever 41b1 is operated, the hydraulic actuator 73 will not start moving immediately. For this reason, when the drive switch 65 detects an instruction to start the electric motor 61, the electric motor 61 is started. Therefore, in this case, it is necessary to execute the notification by the notification unit 66 regarding the start of the electric motor 61. When the drive of the hydraulic excavator 1 is regulated, by determining that the electric motor 61 can be started by the determination unit 80a, the notification unit 66 can execute the notification to let the operator or the like recognize the start of the electric motor 61.

[0058] Also, in S4, the alarm sound output unit 66a outputs an alarm sound (for example, a buzzer sound), so that the operator or the like can surely recognize the start of the electric motor 61.

[0059] Furthermore, in S4, the visual information presentation unit 66b (warning lamp 66b1, display unit 66b2) presents visual information, so that the operator or the like can surely recognize the start of the electric motor 61.

[0060] [4. Determination of Whether the Electric Motor Can Be Started Based on Abnormal Detection] The hydraulic excavator 1 of the present embodiment may include an abnormality detection unit 91. The abnormality detection unit 91 detects the presence or absence of an abnormality in the hydraulic excavator 1 as an operating state of the hydraulic excavator 1. Then, in the startability determination in S2, the determination unit 80a described above may determine that the electric motor 61 cannot be started when the abnormality detection unit 91 detects that there is an abnormality in the hydraulic excavator 1.

[0061] Such an abnormality detection unit 91 may be constituted by a BMU (Battery Management Unit) that collects, for example, the voltages (charge states), temperature information, etc. of a plurality of battery cells constituting the first battery 53, and determines whether the first battery 53 is normal or abnormal.

[0062] More specifically, the first battery 53 is constituted by a plurality of battery modules. Each battery module is constituted by a plurality of cells. The voltage and temperature information of each cell is collected by a CMU (Cell Management Unit). Then, the information collected by the CMU of each battery module is aggregated by the BMU. Thereby, the BMU can determine whether the first battery 53 is normal or abnormal based on the aggregated information.

[0063] If there is an abnormality in the hydraulic excavator 1, the electric motor 61 cannot be started safely even if it is activated, so the electric motor 61 is not started. That is, the main control unit of the ECU 80 does not output a rotation command for starting the electric motor 61 to the inverter 63. When the electric motor 61 is not started, it is not necessary to execute a notification by the notification unit 66 regarding the start of the electric motor 61. Therefore, when there is an abnormality in the hydraulic excavator 1, the determination unit 80a determines that the electric motor 61 cannot be started, so that the notification control unit 80b does not cause the notification unit 66 to execute a notification, and unnecessary notifications by the notification unit 66 can be eliminated.

[0064] On the other hand, in the startability determination of S2, the determination unit 80a may determine that the electric motor 61 is startable when the abnormality detection unit 91 detects no abnormality in the hydraulic excavator 1.

[0065] When there is no abnormality in the hydraulic excavator 1, the safety of the hydraulic excavator 1 is ensured. Therefore, when the drive switch 65 detects an instruction to start the electric motor 61, the main control unit of the ECU 80 outputs a rotation command for starting the electric motor 61 to the inverter 63 to start the electric motor 61. Therefore, when the abnormality detection unit 91 detects no abnormality in the hydraulic excavator 1, the determination unit 80a determines that the electric motor 61 is startable, so that the notification control unit 80b can cause the notification unit 66 to execute a notification based on the determination result of the determination unit 80a. By the above notification, the start of the electric motor 61 can be recognized by an operator or the like.

[0066] Note that the above-described abnormality detection unit 91 is not limited to the above-described BMU, and may include, for example, sensors that detect abnormalities related to temperature, voltage, communication, etc. in each part of the hydraulic excavator 1. For example, the inverter 63 is provided with sensors that detect various abnormalities such as temperature, voltage, and current of the inverter 63, communication abnormalities with the ECU 80, and abnormalities of the internal ECU of the inverter 63, and such sensors may also constitute the abnormality detection unit 91. Further, the electric motor 61 is provided with sensors that detect temperature abnormalities and rotation abnormalities of the electric motor 61, and such sensors may also constitute the abnormality detection unit 91.

[0067] Note that when the abnormality detection unit 91 is configured to include a plurality of sensors, if an abnormality is detected by any one of the sensors, the determination unit 80a can determine that the electric motor 61 cannot be started, and when no abnormality is detected by all the sensors, it can be determined that the electric motor 61 can be started.

[0068] 〔5. Determination of Whether the Electric Motor Can Be Started Based on the Driving Mode〕 In S2 of FIG. 3, the determination unit 80a may determine that the electric motor 61 cannot be started when the charge mode setting switch 67 (see FIG. 2) detects the setting of the charge mode.

[0069] In the charge mode, power is supplied from the external power source 51 to the first battery 53 via the power feeder 62, and the first battery 53 is charged. While the first battery 53 is being charged, the electric motor 61 is not driven. That is, the main control unit of the ECU 80 does not output a rotation command for starting the electric motor 61 to the inverter 63. When the electric motor 61 is not started, it is not necessary to execute a notification by the notification unit 66 regarding the start of the electric motor 61. Therefore, when the charge mode setting switch 67 detects the setting of the charge mode, by determining that the electric motor 61 cannot be started by the determination unit 80a, the notification control unit 80 can prevent the notification unit 66 from executing a notification, and unnecessary notifications by the notification unit 66 can be eliminated.

[0070] In addition to the charging mode, the drive mode of the hydraulic excavator 1 may also include an external power supply mode. The external power supply mode is a drive mode in which, when the electric motor 61 is driven, the power supplied from the external power supply 51 is supplied to the inverter 63 via the power feeder 62 and the power is directly consumed. At this time, when the determination unit 80a determines that the drive mode is the external power supply mode based on the detection result of the charging mode setting switch 67, the determination unit 80a may determine that the electric motor 61 can be started.

[0071] In the external power supply mode, the power supplied from the external power supply 51 is directly used for driving the electric motor 61. Whether the drive mode of the hydraulic excavator 1 is the external power supply mode or not can be determined by the determination unit 80a based on the detection result of the charging mode setting switch 67. For example, when the charging mode setting switch 67 detects the setting of the charging mode, the drive mode is the charging mode and not the external power supply mode. Conversely, when the charging mode setting switch 67 does not detect the setting of the charging mode, it can be determined that the drive mode is not the charging mode but the external power supply mode.

[0072] When the determination unit 80a determines that the drive mode is the external power supply mode and determines that the electric motor 61 can be started, the notification control unit 80b can cause the notification unit 66 to execute a notification based on the determination result of the determination unit 80a. By the above notification, the operator or the like can recognize the start of the electric motor 61.

[0073] By the way, in the startability determination of S2 in FIG. 3, when the determination unit 80a determines that the electric motor 61 cannot be started, the notification control unit 80b may cause the display unit 66b2 to display information indicating the cause of the inability to start the electric motor 61 before ending the notification control.

[0074] FIG. 5 shows an example of the display screen of the display unit 66b2 when the determination unit 80a determines that the electric motor 61 cannot be started. In FIG. 5, an icon P1 indicating that the cutoff lever 41b2 is rotated to the lower position is displayed on the display unit 66b2. This icon display indicates that since the cutoff lever 41b2 is rotated to the lower position, the cutoff switch 41c is turned on and the drive restriction of the hydraulic excavator 1 is released, and thus the determination unit 80a determines that the electric motor 61 cannot be started.

[0075] In this way, by causing the display unit 66b2 to display information (for example, the icon P1) that causes the electric motor 61 not to be startable, an operator or the like can immediately and easily recognize the cause (for example, the cutoff switch 41c being turned on) why the electric motor 61 cannot be started by looking at the information displayed on the display unit 66b2. Then, the operator or the like can also perform confirmation or inspection as necessary.

[0076] As described above, the abnormality detection unit 91 shown in FIG. 2 can collect information regarding the voltages of the plurality of battery cells constituting the first battery 53. Thereby, the abnormality detection unit 91 can detect the remaining power amount (battery remaining capacity) of the first battery 53.

[0077] In the configuration in which the hydraulic excavator 1 includes the first battery 53 that stores electric power for driving the electric motor 61 and the abnormality detection unit 91 as the remaining amount detection unit that detects the remaining power amount of the first battery 53, the display unit 66b2 can switch the display screen as follows according to the state of the hydraulic excavator 1.

[0078] ​FIG. 6 shows an example of the transition of the display screen of the display unit 66b2. When the operator turns the key to give an instruction to start the electric motor 61, if the cut-off lever 41b2 is turned downward, the cut-off switch 41c is turned on, and the drive control of the hydraulic excavator 1 by the drive control unit 90 is released. In this case, as described above, since the determination unit 80a determines that the electric motor 61 cannot be started, the display screen of the display unit 66b2 transitions from the upper left figure to the lower left figure in FIG. 6. That is, visual information (for example, the character 'READY') indicating that the electric motor 61 can be started is not displayed on the display unit 66b2 (the visual information is not displayed). Also, since the drive control of the hydraulic excavator 1 is released, regulation information indicating that the drive of the hydraulic excavator 1 is regulated is not displayed on the display unit 66b2 (the regulation information is not displayed). Note that the remaining amount information F1 indicating the remaining amount of power of the first battery 53 is displayed on the display unit 66b2.

[0079] On the other hand, when the operator turns the key to give an instruction to start the electric motor 61, if the cut-off lever 41b2 is turned upward, the cut-off switch 41c is turned off, and the drive of the hydraulic excavator 1 is regulated by the drive control unit 90. In this case, as described above, since the determination unit 80a determines that the electric motor 61 can be started, the display screen of the display unit 66b2 transitions from the upper left figure to the upper right figure in FIG. 6. That is, visual information F2 (for example, the character 'READY') indicating that the electric motor 61 can be started is displayed on the display unit 66b2 side by side with (or adjacent to) the remaining amount information F1. Also, since the drive of the hydraulic excavator 1 is regulated, regulation information F3 indicating that the drive of the hydraulic excavator 1 is regulated is also displayed on the display unit 66b2. Note that when an instruction to start the electric motor 61 is given and the cut-off lever 41b2 is turned downward, and then the cut-off lever 41b2 is turned upward from there, the display screen of the display unit 66b2 transitions from the lower left figure to the upper right figure in FIG. 6.

[0080] When the electric motor 61 is started and the operator rotates the cut-off lever 41b2 downward, the cut-off switch 41c is turned on, and the drive control of the hydraulic excavator 1 by the drive control unit 90 is released. As a result, the operator can operate various levers 41b to drive the hydraulic excavator 1 to perform work. Note that, since the drive control of the hydraulic excavator 1 is released by rotating the cut-off lever 41b2 downward, the display screen of the display unit 66b2 transitions from the upper right figure to the lower right figure in FIG. 6. That is, the regulation information F3 that was being displayed becomes non-displayed on the display unit 66b2.

[0081] As described above, the visual information presenting unit 66 includes the display unit 66b2 as an information display unit. And the display unit 66b2 displays the remaining amount information F1 indicating the remaining power amount and the visual information F2 regarding the start of the electric motor 61 according to the state of the drive control unit 90 (see the upper right figure in FIG. 6). Thereby, the operator can recognize, by looking at the display screen of the display unit 66b2, that it is in a state where the electric motor 61 can be started, together with the remaining power amount of the first battery 53 at that time.

[0082] Also, the display unit 66b2 displays the remaining amount information F1 and the visual information F2 side by side (see the upper right figure in FIG. 6). Thereby, the operator can immediately and simultaneously recognize these pieces of information with little eye movement on the display screen of the display unit 66b2.

[0083] Also, when the drive of the hydraulic excavator 1 is regulated by the drive control unit 90, the display unit 66b2 displays regulation information F3 indicating that the drive is regulated (see the upper right figure in FIG. 6). Thereby, the operator can recognize, by looking at the display screen of the display unit 66b2, that the drive of the hydraulic excavator 1 is regulated and that there is no problem in starting the electric motor 61 (for example, the hydraulic excavator 1 does not start immediately).

[0084] Further, before the electric motor 61 is started, when the drive control of the hydraulic excavator 1 by the drive control unit 90 is released, the display unit 66b2 turns off the visual information F2 and the restriction information F3 (see the lower left figure in FIG. 6). Thereby, the operator can simultaneously recognize from the display screen of the display unit 66b2 that the electric motor 61 cannot be started and that the drive control of the hydraulic excavator 1 has been released.

[0085] FIG. 7 shows another example of the transition of the display screen of the display unit 66b2. When the operator turns the key to give an instruction to start the electric motor 61 and the cut-off lever 41b2 is in the state of rotating upward, that is, when the drive of the hydraulic excavator 1 is restricted by the drive control unit 90, if the abnormality detection unit 91 detects an abnormality in the hydraulic excavator 1, the determination unit 80a determines that the electric motor 61 cannot be started. In this case, the display unit 66b2 may display abnormality information F4 indicating that there is an abnormality in the hydraulic excavator 1. In the figure, an example is shown in which the abnormality detection unit 91 detects that the first battery 53 has become hot, and the display unit 66b2 displays the abnormality information F4 indicating that the first battery 53 has become hot. At this time, since it is determined that the electric motor 61 cannot be started, the visual information regarding the start of the electric motor 61 is not displayed (becomes non-displayed) on the display unit 66b2, and the non-startable information F5 (the character "Error") indicating that it cannot be started is displayed.

[0086] As described above, when the abnormality detection unit 91 detects an abnormality in the hydraulic excavator 1, the display unit 66b2 as the information display unit displays the abnormality information F4 indicating that there is an abnormality. Thereby, the operator can immediately recognize from the display screen of the display unit 66b2 that an abnormality has occurred in the hydraulic excavator 1.

[0087] Further, when the abnormality detection unit 91 detects an abnormality in the hydraulic excavator 1, the display unit 66b2 turns off the visual information regarding the activation of the electric motor 61. As a result, the operator can recognize from the display screen of the display unit 66b2 that the electric motor 61 cannot be activated in the current state.

[0088] Further, the abnormality information F4 indicates, for example, that the first battery 53 has become hot, which also indicates the cause why the electric motor 61 cannot be activated. By displaying such abnormality information F4 on the display unit 66b2, the operator can immediately recognize from the display screen of the display unit 66b2 the cause why the electric motor 61 cannot be activated and can promptly take necessary measures such as confirmation and inspection.

[0089] In the above description, as an example of an electric working machine, a hydraulic excavator, which is a construction machine, has been described. However, the working machine is not limited to a hydraulic excavator and may be other construction machines such as a wheel loader, or may be agricultural machines such as a combine harvester and a tractor.

[0090] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and it can be implemented with expansion or modification without departing from the gist of the invention.

Industrial Applicability

[0091] The present invention can be applied to working machines such as construction machines and agricultural machines.

Explanation of Reference Numerals

[0092] 1 Hydraulic excavator (electric working machine) 41c Cut-off switch (drive control unit) 51 External power supply 53 First battery 61 Electric motor 62 Power feeder 61a Rotation speed sensor 65 Drive switch 66 Notification unit 66a Alarm sound output unit 66b Visual information presentation unit 66b2 Display unit (information display unit) 67 Charging mode setting switch (charging mode setting detection unit) 80a Judgment unit 80b Notification control unit 90 Drive control unit 91 Abnormality detection unit (remaining amount detection unit) F1 Remaining amount information F2 Visual information F3 Regulation information F4 Abnormality information

Claims

1. A control method for a working machine including a cut-off lever that is driven by an electric motor and operates the machine body into a non-drivable state or a drivable state, comprising: when the electric motor is in a drivable state based on a start instruction of the electric motor in the non-drivable state of the machine body, displaying a first screen on a display unit. A control method for a working machine having this.

2. The control method for a working machine according to claim 1, further comprising: when the electric motor is in a drivable state based on a start instruction of the electric motor in the drivable state of the machine body, displaying a second screen on the display unit.

3. The control method for a working machine according to claim 2, wherein when the second screen is being displayed on the display unit, the electric motor is in a non-drivable state.

4. The control method for a working machine according to claim 3, further comprising: when the second screen is being displayed on the display unit and the machine body is made non-drivable by operating the cut-off lever, displaying the first screen on the display unit.

5. The control method for a working machine according to claim 4, wherein the second screen is displayed by superimposing visual information on the first screen.

Images