Work machine

Abstract

This work machine is provided with: a lower traveling body; an upper rotating body provided so as to be capable of rotating relative to the lower traveling body by means of the rotating mechanism; a working device attached to the upper rotating body; an electric device that uses electric power and generates drive energy for operating the lower traveling body, the turning mechanism, and the work device; a power supply port to which a power cable connected to an external power source can be attached and detached; and a power storage device that can be charged using power supplied from the external power source via the power cable connected to the power supply port, and that can discharge power for generating the drive energy. The control device restricts the operation of at least one of the lower traveling body, the turning mechanism, and the work device when the connection of the power cable to the power supply port is detected by the connection detection device and the loss of the connection of the power cable is detected.

Description

Technical Field

[0001] This invention relates to work machinery. Background Technology

[0002] In recent years, as a solution to global warming, electric work machinery has been known as a type of work equipment that does not emit greenhouse gases. This type of machinery uses an electric motor to drive a hydraulic pump, which in turn supplies hydraulic oil to the actuators, causing them to move. For such electric work machinery, an external power source is sometimes used as one of the power sources for the inverter that controls the electric motor. Specifically, an external power source located in a designated area is connected to the electric work machinery via a cable. The power supplied from this external power source is used to operate the inverter, thereby driving the electric motor and enabling the work machinery to move.

[0003] If the operating machinery operates its actuators while connected to an external power source via cable as described above, the cable may be subjected to excessive physical loads due to various reasons, such as the machinery's rotational motion causing it to be pulled roughly, or the machinery running over it while in motion. This poses a risk of cable damage and therefore needs to be minimized as much as possible.

[0004] In contrast to the aforementioned issues, for example, there is the technology known in Patent Document 1. Patent Document 1 describes a working machine having a detection mechanism for detecting the connection between a power cable and a connector, and a control mechanism for prohibiting or limiting the operation of at least one of the electric drive mechanisms when the detection mechanism detects the connection between the power cable and the connector. When the detection mechanism detects the connection between the power cable and the connector, although the movement of the lower traveling body is possible, the travel speed is limited to a low speed or a snail's pace. Existing technical documents Patent documents

[0005] Patent Document 1: Japanese Patent No. 5004834 Summary of the Invention

[0006] The operating machinery described in Patent Document 1 limits its travel speed to a low or even snail's pace when the power cable is connected to the connector on the vehicle body. However, even under this speed limit, the power cable may still disconnect from the connector and detach due to the operation of the operating machinery. In this case, if the operating machinery can continue to operate using power from its internal battery while the power cable is disconnected, there is still a risk that the operation of the operating machinery may damage the power cable. However, Patent Document 1 does not consider the action of the power cable when it detaches, and therefore, in this situation, it cannot adequately suppress damage to the power cable.

[0007] The present invention was made in view of the above points, and its object is to provide a working machine that can suppress cable damage even if the cable supplying power from the power supply device to the working machine falls off the working machine.

[0008] The working machine of the present invention comprises: a lower traveling body; an upper rotating body connected to the lower traveling body via a rotating mechanism, configured to rotate relative to the lower traveling body via the rotating mechanism; a working device mounted on the upper rotating body; an electric device that uses electricity to generate driving energy for operating the lower traveling body, the rotating mechanism, and the working device respectively; a power supply port for attaching and detaching a power cable connected to an external power source; a power storage device capable of being charged using electricity supplied from the external power source via the power cable connected to the power supply port, and capable of discharging the electricity used to generate the driving energy; and a control device that controls the operation of the lower traveling body, the rotating mechanism, and the working device. The working machine includes a connection detection device that detects the connection status of the power cable to the power supply port. After the connection detection device detects the connection of the power cable to the power supply port, when the connection of the power cable is detected to be lost, the control device restricts the operation of at least one of the lower traveling body, the rotating mechanism, and the working device. Invention Effects

[0009] According to the present invention, even if the cable supplying power from the power supply device to the working machinery falls off the working machinery, cable damage can be suppressed.

[0010] Furthermore, other features associated with the present invention will become clear from the description and drawings herein. Additionally, issues, configurations, and effects other than those described above will become clear from the following description of embodiments. Attached Figure Description

[0011] Figure 1 This is an external view of an example of an operating machine according to one embodiment of the present invention, namely an electric hydraulic excavator. Figure 2 This is a configuration diagram of the control system of the working machine according to the first embodiment of the present invention. Figure 3 This is a diagram representing the control flow of motion restriction processing. Figure 4 This is a configuration diagram of the control system of the working machine according to the second embodiment of the present invention. Figure 5 This is a configuration diagram of the control system of the working machine according to the third embodiment of the present invention. Detailed Implementation

[0012] The following describes the implementation of the working machine of the present invention in detail, taking a hydraulic excavator as an example, with reference to the accompanying drawings.

[0013] (First Embodiment) Figure 1 This is an external view of an example of an electric hydraulic excavator according to one embodiment of the present invention. The electric hydraulic excavator 1 includes: a lower traveling body 2 having a pair of tracks 5 on the left and right sides; an upper rotating body 3 disposed on the lower traveling body 2 and connected to the lower traveling body 2 via a rotating mechanism 4; a boom 8 rotatably connected to one end of the upper rotating body 3; a stick 9 rotatably connected to one end of the boom 8; and a bucket 10 rotatably connected to one end of the stick 9.

[0014] On the lower traveling body 2, a travel motor 35 is provided on each of the left and right pairs of tracks 5 to drive the tracks 5 to rotate. The lower traveling body 2 drives the left and right tracks 5 to rotate in either direction via the travel motors 35, thereby enabling any of the following driving actions: forward movement, backward movement, or changing direction.

[0015] The upper rotating body 3 is equipped with a cabin 7 for the operator to ride in in order to operate the hydraulic excavator 1. A rotating motor 34 (see reference) is provided on the rotating mechanism 4 that connects the lower traveling body 2 and the upper rotating body 3. Figure 2 By driving the rotary motor 34, the upper rotary body 3 can rotate relative to the lower traveling body 2 at any angle via the rotary mechanism 4.

[0016] In the hydraulic excavator 1, the boom 8, stick 9, and bucket 10, mounted on the upper rotating body 3, constitute the working device for digging and other operations. The boom 8 and the upper rotating body 3 are connected via a boom cylinder 31. The stick 9 and the boom 8 are connected via a stick cylinder 32. The bucket 10 and the stick 9 are connected via a bucket cylinder 33. The hydraulic excavator 1 supplies hydraulic pressure to the boom cylinder 31, stick cylinder 32, and bucket cylinder 33 respectively, causing these hydraulic cylinders to extend and retract, thereby enabling the boom 8, stick 9, and bucket 10 to move independently to perform digging and other operations.

[0017] A power supply port 90 is provided on the upper rotating body 3. The power supply port 90 has a structure that allows for connection and detachment of a power cable 92 to an external power source 100 located near the hydraulic excavator 1. The hydraulic excavator 1 can receive power from the external power source 100 via the power cable 92 connected to the power supply port 90. The power supplied from the external power source 100 powers the battery 40 (see reference 1) built into the hydraulic excavator 1. Figure 2 The charging is used to generate hydraulic pressure to enable the rotary motor 34 and the travel motor 35, as well as the hydraulic cylinders of the working device (boom cylinder 31, stick cylinder 32, bucket cylinder 33) to operate respectively.

[0018] Figure 2 This is a configuration diagram of the control system of the working machine according to the first embodiment of the present invention. Figure 2 The control system 200 shown is for performing Figure 1 The motion control system of the hydraulic excavator 1 shown includes a rotary motor 34 and a travel motor 35 as hydraulic motors, a boom cylinder 31, a stick cylinder 32 and a bucket cylinder 33 as hydraulic cylinders, a hydraulic pump 50, a pilot pump 51 and a control valve unit 53 for generating and regulating the hydraulic pressure supplied to these actuators respectively.

[0019] Hydraulic pump 50 and pilot pump 51 are mechanically connected to electric motor 60. Electric motor 60 is driven to rotate by AC power supplied from inverter 70, driving hydraulic pump 50 and pilot pump 51 to generate hydraulic pressure. Hydraulic pressure generated by hydraulic pump 50 is output to control valve unit 53, and hydraulic pressure generated by pilot pump 51 is output to control valve unit 53 via operating device 21.

[0020] The operating device 21 within compartment 7 is configured in the hydraulic circuit between the pilot pump 51 and the control valve unit 53. If the operator operates the operating device 21 from within compartment 7, hydraulic pressure is output from the pilot pump 51 to the control valve unit 53 according to the lever operation. The control valve unit 53 then adjusts the flow from the hydraulic pump 50 to each actuator. Thus, the hydraulic pressure generated by the hydraulic pump 50 is supplied to each actuator according to the lever operation of the operating device 21, causing each actuator to actuate.

[0021] In the control system 200, as described above, the hydraulic pump 50 and the pilot pump 51 are driven by the rotational force of the electric motor 60, which uses electricity. This supplies hydraulic pressure to the travel motor 35, the swing motor 34, the boom cylinder 31, the stick cylinder 32, and the bucket cylinder 33, enabling the lower traveling body 2, the swing mechanism 4, and the working device (boom 8, stick 9, bucket 10) to operate respectively. In other words, the electric motor 60 uses electricity to rotate, thereby generating hydraulic pressure from the hydraulic pump 50 and the pilot pump 51 to supply these actuators as driving energy for the operation of the lower traveling body 2, the swing mechanism 4, and the working device.

[0022] An inverter 70 is connected to the electric motor 60. The inverter 70 converts the DC power supplied from the power conversion device 80 and the battery 40 into AC power, which is then supplied to the electric motor 60 to drive its rotation. The power conversion device 80 is connected to an external power source 100 via a power port 90 and a power cable 92, converting the AC power supplied from the external power source 100 into DC power and outputting it to the inverter 70 and the battery 40. The battery 40 is charged by the DC power output from the power conversion device 80, and the charged power is supplied to the inverter 70 as needed. The power conversion device 80, the inverter 70, and the battery 40 are interconnected via a power line 41.

[0023] in addition, Figure 2 The control system 200 shown includes a body controller 20, a monitor 22, and a position sensor 24. The body controller 20 is connected to the power conversion unit 80, inverter 70, battery 40, and hydraulic pump 50 via signal lines 42, and outputs prescribed control signals via signal lines 42 to control these components. For example, the hydraulic pressure output from the pilot pump 51 to the control valve unit 53 is detected by the pressure sensor 54, and a signal corresponding to the detection result is sent to the body controller 20. Furthermore, the current position of the hydraulic excavator 1, the position (posture) of the upper swing body 3 and the working devices (boom 8, stick 9, bucket 10) relative to the lower traveling body 2 is detected by the position sensor 24, and a signal corresponding to the detection result is sent to the body controller 20. Based on the signals sent from the pressure sensor 54 and the position sensor 24, the body controller 20 controls the AC power output from the inverter 70 to the electric motor 60, thereby regulating the speed of the electric motor 60 to ensure that the hydraulic fluid discharged from the hydraulic pump 50 reaches a specified flow rate, and adjusting the volume of the variable-capacity hydraulic pump 50. In addition to these, the body controller 20 can also perform various other controls to operate the hydraulic excavator 1.

[0024] A connection detection device 91 is provided between the power supply port 90 and the power conversion device 80. The connection detection device 91 detects the connection status of the power cable 92 to the power supply port 90 and sends a specified cable connection signal to the body controller 20 via the signal line 42. Based on the presence or absence of the cable connection signal sent from the connection detection device 91, the body controller 20 performs action restriction processing to restrict the movement of at least one of the lower traveling body 2, the rotary mechanism 4, and the working device in accordance with the connection status of the power cable 92. (Refer to the following...) Figure 3 Provide its detailed content. In addition, the connection detection device 91 can be a mechanism that detects the connection of the power cable 92 to the power supply port 90 mechanically or electrically through a switch, or it can be configured to detect the function of the power conversion device 80 input by the external power supply 100 to the power conversion device 80.

[0025] Figure 3 This is a diagram illustrating the control flow of motion restriction processing performed in a work machine according to one embodiment of the present invention. Figure 3 The control flow shown is executed, for example, in the body controller 20, according to each prescribed processing cycle.

[0026] In step S10, the vehicle body controller 20 determines whether a cable connection signal is sent from the connection detection device 91. If a cable connection signal is sent from the connection detection device 91, it determines that a power cable 92 is connected to the power supply port 90 and proceeds to step S20. If no cable connection signal is sent from the connection detection device 91, it determines that no power cable 92 is connected to the power supply port 90 and stops at step S10.

[0027] In step S20, the vehicle body controller 20 determines whether the rotational speed of the electric motor 60 is greater than 0 based on the signal indicating the control state of the electric motor 60 sent from the inverter 70. If the rotational speed of the electric motor 60 is greater than 0, it is determined that the hydraulic excavator 1 is in operation and proceeds to step S30. If the rotational speed of the electric motor 60 is 0, it is determined that the hydraulic excavator 1 is in a non-operational state and returns to step S10.

[0028] In step S30, the vehicle body controller 20 restricts the movement of the power cable connection. Here, the movement of at least one of the lower traveling body 2, the rotary mechanism 4, and the working device is restricted according to pre-set limits. For example, the travel speed of the lower traveling body 2 is limited to a predetermined speed or lower. Specifically, when the operator instructs the travel movement via the lever of the operating device 21, the drive speed of the travel motor 35 is suppressed, and the travel speed of the lower traveling body 2 is limited to a predetermined speed or lower. This control can be achieved, for example, by varying the speed command of the electric motor 60 to the inverter 70, and limiting the flow rate of hydraulic pressure supplied from the hydraulic pump 50 to the travel motor 35 via the control valve unit 53 to a predetermined value or lower. This prevents the power cable 92 connected to the power supply port 90 from accidentally detaching due to the movement of the lower traveling body 2.

[0029] Furthermore, the restrictions on the movement of the power cable connection in step S30 are not limited to the above. As long as the movement of at least one of the lower traveling body 2, the slewing mechanism 4, and the working device is restricted, and the prevention of power cable 92 detachment and the safety during operation are effectively ensured, the body controller 20 can implement the restrictions on the movement of the power cable connection in step S30 in any way.

[0030] In step S40, the vehicle body controller 20, similar to step S10, determines whether a cable connection signal sent from the connection detection device 91 is present. If a cable connection signal is sent from the connection detection device 91, it is determined that the power cable 92 connected to the power supply port 90 has not been disconnected, and the operation is limited to return to step S30 and continue the power cable connection process. On the other hand, if no cable connection signal is sent from the connection detection device 91, the power cable 92 has been disconnected from the power supply port 90, and therefore it is determined that the connection of the power cable 92 has been detected by the connection detection device 91, and the process proceeds to step S50.

[0031] In step S50, the body controller 20 notifies the operator of the disconnection of the power cable 92. Here, for example, a prescribed notification screen is displayed on the monitor 22 installed in the compartment 7, thereby enabling the operator to recognize that the power cable 92 has been disconnected from the power supply port 90.

[0032] In step S60, the vehicle body controller 20 implements action restrictions when the power cable is disconnected. Here, according to preset restrictions, the action of at least one of the lower traveling body 2, the slewing mechanism 4, and the working device is restricted. For example, the traveling action of the lower traveling body 2 is prohibited, or restricted to a speed below a specified limit. Specifically, when the operator instructs the traveling action via the lever of the operating device 21, the driving of the traveling motor 35 is prohibited, or its driving speed is suppressed, thus limiting the traveling speed of the lower traveling body 2 to a speed below a specified limit. The speed limit at this time may be the same as or different from the speed limit implemented in step S30 when the power cable is connected. This control can be achieved, for example, by prohibiting or limiting the hydraulic pressure output as an operating signal from the pilot pump 51 to the control valve unit 53 via the operating device 21, or by changing the speed command of the electric motor 60 to the inverter 70, thereby stopping or limiting the flow of hydraulic pressure supplied from the hydraulic pump 50 to the traveling motor 35 via the control valve unit 53 to a specified value. This prevents the power cable 92 from being accidentally run over by the lower traveling body 2 and detached from the power supply port 90.

[0033] Furthermore, the aforementioned restrictions on movement when a power cable detaches can also prohibit or restrict the movement of the lower traveling body 2 in any forward or backward direction. Specifically, since the power supply port 90 is located at the rear end of the upper rotating body 2, the direction of the power cable's extension can be inferred from the position (or orientation) of the upper rotating body 2, thereby prohibiting movement in the direction of the power cable's extension or limiting the speed to below a specified speed. Alternatively, based on the positional relationship between the lower traveling body 2 and the external power source 100, movement in the direction approaching the external power source 100 during forward or backward movement can be prohibited or the speed limited to below a specified speed, while movement in the direction away from the external power source 100 is not restricted. By doing so, the operability of the hydraulic excavator 1 can be ensured as much as possible, while effectively preventing the power cable 92 from being crushed.

[0034] Alternatively, the rotational movement of the slewing mechanism 4 can be prohibited or restricted, either as a substitute for or based on the movement of the lower traveling body 2. Specifically, when the operator instructs the operator to perform a rotational movement via the lever of the operating device 21, the driving of the slewing motor 34 is prohibited, or its driving speed is suppressed, and the rotational speed of the upper slewing body 3 is limited to below a specified speed. Alternatively, the rotational range can be limited to a specified range based on the positional relationship between the upper slewing body 3 and the external power supply 100. This prevents the power cable 92 detached from the power supply port 90 and workers present around the hydraulic excavator 1 from being caught in the upper slewing body 3 and the working device due to the rotational movement of the upper slewing body 3.

[0035] Furthermore, the action restrictions in step S60 when the power cable detaches are not limited to those described above. As long as the action of at least one of the lower traveling body 2, the slewing mechanism 4, and the working device is restricted, and this is effective in preventing damage to the detached power cable 92 and ensuring safety during operation, the vehicle body controller 20 can implement action restrictions in step S60 with any content. These restrictions can be the same as or different from those in step S30.

[0036] In step S70, the body controller 20 determines whether a predetermined release command has been input in response to the notification of the detachment of the power cable 92 to the operator implemented in step S50. If, based on the detachment of the power cable 92, the notification screen described above is displayed on the monitor 22, the operator, after confirming the surrounding safety as needed, performs the predetermined release operation by operating the monitor 22 (which is a touch panel) and an operation switch (not shown) located in the compartment 7. If a release command is sent from the monitor 22 and the operation switch to the body controller 20 based on this release operation, the body controller 20 determines in step S70 that a release command has been input and proceeds to step S80. On the other hand, if the operator has not performed a release operation and has not input a release command to the body controller 20, the process returns to step S40 and repeats the above process.

[0037] In step S80, the vehicle body controller 20 releases the movement restriction imposed when the power cable detaches. Here, the restrictions imposed in step S60 on the movement of at least one of the lower traveling body 2, the slewing mechanism 4, and the working device are released. The travel motor 35, the slewing motor 34, the boom cylinder 31, the stick cylinder 32, and the bucket cylinder 33 then perform actions corresponding to the operation of the operating device 21. Thus, the operator, having determined that the hydraulic excavator 1 can be safely operated, eliminates the reduction in work efficiency caused by movement restrictions, enabling efficient operation.

[0038] After performing step S80, the process ends. Figure 3 The control process.

[0039] In the control system 200 of this embodiment, the vehicle body controller 20 performs the motion control processing described above, thereby ensuring safety in both the case where the power cable 92 is connected and the case where the power cable 92 is detached, while suppressing damage to the power cable 92.

[0040] According to the first embodiment of the present invention described above, the following effects are achieved.

[0041] (1) The hydraulic excavator 1, as a working machine, has: a lower traveling body 2; an upper rotating body 3 connected to the lower traveling body 2 via a rotating mechanism 4, which is configured to be able to rotate relative to the lower traveling body 2 via the rotating mechanism 4; a working device (boom 8, stick 9, bucket 10) mounted on the upper rotating body 3; an electric device (electric motor 60) that uses electricity to generate driving energy for the lower traveling body 2, the rotating mechanism 4 and the working device to move respectively; a power supply port 90 that allows the installation and removal of a power cable 92 connected to an external power source 100; an energy storage device (battery 40) that can be charged using electricity supplied from the external power source 100 via the power cable 92 connected to the power supply port 90, and can discharge the electricity used to generate driving energy; and a control device (body controller 20) that controls the movement of the lower traveling body 2, the rotating mechanism 4 and the working device. After the power cable 92 is connected to the power supply port 90, when a loss of connection of the power cable 92 is detected (step S40: No), the vehicle body controller 20 restricts the operation of at least one of the lower traveling body 2, the slewing mechanism 4, and the working device (step S60). Because of this, even if the power cable 92, which supplies power to the hydraulic excavator 1 from the external power source 100 as a power supply device, detaches from the hydraulic excavator 1, damage to the power cable 92 can be sufficiently suppressed.

[0042] (2) In step S60, the vehicle body controller 20, for example, prohibits the driving action of the lower driving body 2 or limits the driving speed to below a specified speed. If this is done, the lower driving body 2 can be prevented from accidentally running over the power cable 92 when it detaches from the power supply port 90.

[0043] (3) In step S60, the body controller 20 can also, for example, restrict the movement of the lower traveling body 2 relative to any direction of forward or backward movement, or limit the travel speed to below a specified speed. If this is done, the operability of the hydraulic excavator 1 can be ensured as much as possible when the power cable 92 is detached from the power supply port 90, while effectively preventing the lower traveling body 2 from accidentally running over the power cable 92.

[0044] (4) In addition, in step S60, the vehicle body controller 20 may also prevent the upper rotating body 3 from rotating due to the rotating mechanism 4 or limit the rotating range to a specified range. If this is done, when the power cable 92 is detached from the power supply port 90, it can prevent the power cable 92 and the operator present around the hydraulic excavator 1 from being caught in the upper rotating body 3 and the working device due to the rotating action.

[0045] (5) When the vehicle body controller 20 is in the state where the power cable 92 is connected to the power supply port 90 (step S10: Yes), it restricts the operation of at least one of the lower driving body 2, the rotary mechanism 4, and the working device (step S30). Because of this, it is possible to prevent the power cable 92 connected to the power supply port 90 from accidentally falling off.

[0046] (6) Alternatively, the vehicle body controller 20 may restrict the operation of at least one of the lower traveling body 2, the slewing mechanism 4, and the working device with different content by implementing action restrictions in step S30 when the power cable 92 is connected to the power supply port 90, and implementing action restrictions in step S60 when the power cable 92 is detected to be disconnected. If this is done, appropriate action restrictions corresponding to each situation can be performed when the power cable 92 is connected and disconnected.

[0047] (7) If the vehicle body controller 20 detects that the connection of the power cable 92 has been lost (step S40: no), it notifies the operator (step S50). Because of this, when the power cable 92 is disconnected from the power supply port 90, the situation can be notified and the operator's attention can be urged.

[0048] (8) The hydraulic excavator 1 has a monitor 22, such as a touch panel, as an input device for receiving input operations from the operator. After the operator is notified in step S50, the body controller 20 releases the restriction on the movement of at least one of the following components via the monitor 22 when the operator performs a specified release operation (step S70: Yes) (step S80). Because of this, when the operator determines that the hydraulic excavator 1 can ensure safety, the reduction in work efficiency due to movement restrictions can be eliminated, and efficient work can be carried out.

[0049] (Second Implementation) In this embodiment, an example of motion control of the hydraulic excavator 1 is described using a system configuration different from that of the control system 200 described in the first embodiment.

[0050] Figure 4 This is a configuration diagram showing the control system of the working machine according to the second embodiment of the present invention. Figure 4 In the control system 200A shown, with Figure 1The main difference in the control system 200 is that the operating device 21 is an electrical operating device, which sends an operating signal corresponding to its operation to the body controller 20, and the control valve unit 53 is equipped with an electromagnetic pilot valve 52. Other points, such as the appearance and structure of the hydraulic excavator 1, other components of the control system 200A, and the content of the action restriction processing of each actuator based on the connection state of the power cable 92, are the same as those described in the first embodiment. Therefore, hereafter, Figure 4 Based on the above, refer to the descriptions in the first embodiment. Figure 1 Exterior drawings and Figure 3 The control process is described to illustrate the motion control of the operating machinery in this embodiment.

[0051] In this embodiment, the operating device 21 sends an operating signal corresponding to the operator's operation to the body controller 20. Based on the operating signal sent from the operating device 21, the body controller 20 calculates the opening amount of the solenoid pilot valve 52 corresponding to the action of each actuator, and sends an electrical signal corresponding to the calculation result to the solenoid pilot valve 52. Thus, the solenoid pilot valve 52 controls the hydraulic pressure supplied from the pilot pump 51 to the control valve unit 53, thereby controlling the control valve unit 50, and controls the hydraulic pressure supplied from the hydraulic pump 50 to each actuator, causing each actuator to operate.

[0052] in addition, Figure 3 In the control flow, when the action restriction is implemented in step S30 when the power cable is connected, and when the action restriction is implemented in step S60 when the power cable is disconnected, the body controller 20 restricts the action of each actuator by limiting the opening amount of the solenoid pilot valve 52. That is, according to the preset restrictions for the connection and disconnection of the power cable 92, the opening amount of the solenoid pilot valve 52 that causes the corresponding actuator to operate is limited compared to the case where no action restriction is applied. Therefore, the same action restriction as described in the first embodiment can be performed.

[0053] The second embodiment of the present invention described above has the same effects as those described in the first embodiment.

[0054] (Third implementation) In this embodiment, an example of motion control of the hydraulic excavator 1 is described using a system configuration different from that of the control system 200 described in the first and second embodiments.

[0055] Figure 5 This is a configuration diagram of the control system of the working machine according to the third embodiment of the present invention. Figure 5 In the control system 200B shown, with Figure 4 The main difference in the control system 200A is that, instead of the boom cylinder 31, stick cylinder 32, and bucket cylinder 33, electric motors 31B, 32B, and 33B are provided as power sources for the operation of the boom 8, stick 9, and bucket 10, respectively, and inverters 71, 72, and 73 are connected to these electric motors 31B, 32B, and 33B, respectively. Other aspects, such as the appearance and structure of the hydraulic excavator 1, other components of the control system 200B, and the content of the operation restriction processing of each actuator based on the connection state of the power cable 92, are the same as those described in the first and second embodiments. Therefore, hereafter, Figure 5 Based on the above, refer to the descriptions in the first embodiment. Figure 1 Exterior drawings and Figure 3 The control process is described to illustrate the motion control of the operating machinery in this embodiment.

[0056] In this embodiment, the operating device 21, similar to that in the first embodiment, sends an operating signal corresponding to the operator's operation to the vehicle body controller 20. When the vehicle body controller 20 operates the lower traveling body 2 and the slewing mechanism 4 based on the operating signal sent from the operating device 21, it calculates the opening amount of the electromagnetic pilot valve 52 corresponding to these operations and sends an electrical signal corresponding to the calculation result to the electromagnetic pilot valve 52. Furthermore, when the working device is operated, it calculates the rotational speeds of the electric motors 31B, 32B, and 33B corresponding to the respective operations of the boom 8, stick 9, and bucket 10, and sends speed commands corresponding to the calculation results to the inverters 71, 72, and 73. Thus, it controls the hydraulic pressure supplied from the hydraulic pump 50 to the traveling motor 35 and the slewing motor 34 via the control valve unit 53, and controls the drive of the electric motors 31B, 32B, and 33B, causing each actuator to operate.

[0057] in addition, Figure 3 In the control flow, when the action restriction is implemented in step S30 when the power cable is connected, and when the action restriction is implemented in step S60 when the power cable is disconnected, the body controller 20 restricts the action of each actuator by limiting the opening of the solenoid pilot valve 52 and the rotational speed of the electric motors 31B, 32B, and 33B. In other words, according to the preset restrictions for the connection and disconnection of the power cable 92, compared to the case where no action restriction is implemented, the opening of the solenoid pilot valve 52 and the rotational speed of the electric motors 31B, 32B, and 33B when the corresponding actuator is activated are restricted. Therefore, the same action restriction as described in the first embodiment can be performed.

[0058] According to the third embodiment of the present invention described above, it achieves the same effects as those described in the first embodiment.

[0059] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the spirit of the present invention described in the technical solutions. For example, the above embodiments have been described in detail for ease of understanding of the present invention and are not limited to having all the described configurations. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Moreover, for a part of the configuration of each embodiment, other configurations can be added, deleted, or replaced. Explanation of reference numerals in the attached figures

[0060] 1: Hydraulic excavator 2: Lower driving body 3: Upper whirlpool 4: Rotary mechanism 5: Tracks 7: Cabin 8: Boom 9: Fighting pole 10: Bucket 20: Body Controller 21: Operating device 22: Monitor 31: Boom cylinder 32: Bucket cylinder 33: Bucket cylinder 34: Rotary motor 35: Drive motor 40: Storage battery 41: Power Line 42: Signal line 50: Hydraulic pump 51: Pilot pump 52: Electromagnetic pilot valve 53: Control Valve Unit 54: Pressure sensor 60: Electric motor 70: Inverter 80: Power conversion device 90: Power supply port 91: Connect the detection device 92: Power supply cables 100: External power supply 200: Control system.

Claims

1. A work machine having: a lower traveling body; an upper swing body connected to the lower traveling body via a swing mechanism, provided to be swingable relative to the lower traveling body by the swing mechanism; a work device mounted to the upper swing body; an electric power device that generates drive energy for causing the lower traveling body, the swing mechanism, and the work device to act, respectively, using electric power; a power supply port to which a power cable connectable with an external power source is attachable and detachable; an electric storage device that is chargeable using electric power supplied from the external power source via the power cable connected to the power supply port, and is dischargeable to electric power for generating the drive energy; and a control device that controls the actuation of the lower traveling body, the swing mechanism, and the work device, in the work machine, there is a connection detection device that detects a connection state of the power cable to the power supply port, upon detection by the connection detection device of connection of the power cable to the power supply port, when a loss of connection of the power cable is detected, the control device restricts the actuation of at least one of the lower traveling body, the swing mechanism, and the work device.

2. The work machine according to claim 1, wherein, upon detection by the connection detection device of a loss of connection of the power cable, the control device prohibits travel actuation of the lower traveling body or restricts a travel speed to a prescribed speed or less.

3. The work machine according to claim 1, wherein, upon detection by the connection detection device of a loss of connection of the power cable, the control device prohibits swing actuation of the upper swing body based on the swing mechanism or restricts a swing range to a prescribed range.

4. The work machine according to claim 1, wherein, in a state in which the power cable is connected to the power supply port, the control device restricts the actuation of at least one of the lower traveling body, the swing mechanism, and the work device.

5. The work machine according to claim 4, wherein, in the state in which the power cable is connected to the power supply port, and upon detection of a loss of connection of the power cable, the control device respectively restricts the actuation of at least one of the lower traveling body, the swing mechanism, and the work device with different contents from each other. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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