Working machine and control method for working machine

Abstract

To control a work machine for further enhancing safety in the case where abnormality occurs in a power supply circuit outside a controller 10 in addition to the case where abnormality occurs inside the controller.SOLUTION: A work machine 1 having a work machine unit includes a power source 2 for outputting a drive force for operating the work machine unit, a controller 10, and an electromagnetic valve 6 controlled by the controller 10. When determining that abnormality has occurred in a power supply circuit for connecting the controller 10 and the electromagnetic valve 6, the controller 10 outputs a command for controlling the power source 2 so as to restrict the operation of the work machine unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a working machine and a control method for a working machine. [Background Art]

[0002] As a functional safety measure for working machines such as hydraulic excavators, there is a function of detecting an abnormality in the controller and cutting off the electric circuit when an abnormality occurs inside the controller. [Prior Art Literature] [Patent Literature]

[0003] [Patent Literature 1] Japanese Unexamined Patent Publication No. 2019-097022 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In a working machine, it is desired to control the working machine to further improve safety not only when an abnormality occurs inside the controller but also when an abnormality occurs in a power supply circuit external to the controller. [Means for Solving the Problem]

[0005] According to the present disclosure, there is provided a working machine having a working implement, comprising: a power source that outputs a driving force for operating the working implement; a controller; and a solenoid valve controlled by the controller. When the controller determines that an abnormality has occurred in a power supply circuit connecting the controller and the solenoid valve, the controller outputs a command to control the power source so as to restrict the operation of the working implement.

[0006] According to the present disclosure, there is provided a control method for a working machine having a working implement, wherein when it is determined that an abnormality has occurred in a power supply circuit connecting a controller for controlling a solenoid valve and the solenoid valve, a command is output to control a power source so as to restrict the operation of the working implement. [Effect of the Invention]

[0007] According to this disclosure, it is possible to provide a work machine and a method for controlling a work machine that can control the work machine in a way that further enhances safety, not only when an abnormality occurs inside the controller, but also when an abnormality occurs in the power supply circuit outside the controller. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic block diagram of a work machine according to the first embodiment. [Figure 2] Figure 2 is a block diagram showing a computer system according to the first embodiment. [Figure 3] Figure 3 is a flowchart showing a control method for a work machine according to the first embodiment. [Figure 4] Figure 4 is a schematic block diagram of the work machine according to the second embodiment. [Modes for carrying out the invention]

[0009] The embodiments described below will be explained with reference to the drawings, but the disclosure is not limited thereto. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] (First Embodiment) [Working machinery] Figure 1 is a schematic block diagram of a work machine 1 according to the first embodiment. In this disclosure, the work machine 1 is a hydraulic excavator. The work machine 1 comprises a lower traveling body (not shown), an upper rotating body (not shown), a work machine (not shown), and a hydraulic cylinder (not shown) that drives the work machine. The work machine 1 comprises a power source 2, a solenoid valve 6, a battery 4 which is a power source, and a controller 10. In this disclosure, the work machine 1 includes a hydraulic actuator 3, an operating device 5, and a power source controller 30. In this disclosure, the solenoid valve 6 is provided to have, for example, two solenoid valves, solenoid valve 6a and solenoid valve 6b, in addition to solenoid valve 6c connected to the power source 2, but is not limited to this.

[0011] In this disclosure, the work machine 1 may include a notification unit (not shown) that notifies of an abnormality in the power supply circuit outside the controller 10, in other words, the power supply circuit connecting the controller 10 and the solenoid valve 6. The notification unit is a notification device that notifies the operator in the driver's seat of an abnormality in the power supply circuit outside the controller 10. The notification unit is, for example, a monitor or buzzer provided in the driver's cab of the work machine 1.

[0012] Power source 2 outputs driving force to operate the work machine. Power source 2 is controlled by a control signal from power source controller 30. Power source 2 includes, for example, an engine, a generator, a fuel cell, a storage battery, an electric motor, and a variable displacement pump. In this disclosure, power source 2 is described as having, as an example, an engine 2E and a variable displacement pump 2P.

[0013] A solenoid valve 6c is connected to the variable displacement pump 2P. The variable displacement pump 2P is, for example, a swash plate hydraulic pump that changes the pump capacity by changing the tilt angle of the swash plate, but is not limited to this. The variable displacement pump 2P is mechanically connected to the drive shaft 2X of the engine 2E. When the engine 2E is driven, the variable displacement pump 2P is driven. The variable displacement pump 2P is the source of hydraulic fluid supply to the hydraulic actuator 3. In this disclosure, the rotational speed of the engine 2E is controlled by a control signal from the power source controller 30. In this disclosure, the tilt angle of the swash plate of the variable displacement pump 2P is controlled by a control signal from the controller 10.

[0014] The hydraulic actuator 3 is a hydraulic drive system, such as a boom hydraulic cylinder, an arm hydraulic cylinder, a bucket hydraulic cylinder, a right-travel hydraulic motor, and a left-travel hydraulic motor. The hydraulic actuator 3 is driven by hydraulic fluid supplied from a variable displacement pump 2P. When the hydraulic actuator 3 is driven, the work equipment, including the boom, bucket, and arm connected to the hydraulic actuator 3, the lower traveling body, and the upper slewing body are operated. A control valve (not shown) for controlling the hydraulic actuator 3 is located between the hydraulic actuator 3 and the variable displacement pump 2P.

[0015] Battery 4 supplies power to the work machine 1. Battery 4 supplies power to drive the solenoid valve 6. In this disclosure, battery 4 supplies power to drive solenoid valves 6a, 6b, and 6c. Battery 4 supplies power to the controller 10. An electrical signal line 101 is electrically connected to battery 4. Battery 4 is connected to the controller 10 via the electrical signal line 101. Battery 4 is connected to the solenoid valve 6 via the electrical signal line 101 and the controller 10. In this disclosure, battery 4 is connected to solenoid valves 6a, 6b, and 6c via the electrical signal line 101 and the controller 10. In the circuit that supplies power from battery 4 to the controller 10, in other words, the electrical signal line 101, the battery 4 side is referred to as the upstream side.

[0016] The operating device 5 is disposed in the driver's seat of the work machine 1. The operating device 5 is operated by an operator. The operating device 5 is, for example, an operating lever for operating the swinging of a boom, a bucket, an arm, and an upper swinging structure. The operating device 5 is, for example, an operating lever for operating a traveling hydraulic motor. The operating device 5 is, for example, a fuel dial. The operating device 5 is, for example, an operation switch for operating a swing parking brake.

[0017] The operating device 5 outputs a signal indicative of an operator's operation to the control unit 20. The operating device 5 outputs, for example, a boom operation signal indicative of the operation direction and operation amount of the boom to the control unit 20. The operating device 5 outputs, for example, a bucket operation signal indicative of the operation direction and operation amount of the bucket to the control unit 20. The operating device 5 outputs, for example, an arm operation signal indicative of the operation direction and operation amount of the arm to the control unit 20. The operating device 5 outputs, for example, a swing operation signal indicative of the swing direction and swing amount of the upper swinging structure relative to the lower traveling structure to the control unit 20. The operating device 5 outputs, for example, a traveling operation signal for operating the traveling motor to the control unit 20. The operating device 5 outputs, for example, a fuel dial signal indicative of the throttle opening of the engine to the control unit 20. The operating device 5 outputs, for example, a swing parking brake operation signal for operating the engagement or release of the swing parking brake to the control unit 20.

[0018] The solenoid valve 6a performs opening / closing operations, direction switching operations and the like by electric power supplied from the battery 4. The upstream side of the solenoid valve 6a is connected to the downstream side of the switching element 14F. The downstream side of the solenoid valve 6a is connected to the ground 17G.

[0019] The solenoid valve 6b performs opening / closing operations, direction switching operations and the like by electric power supplied from the battery 4. The upstream side of the solenoid valve 6b is connected to the downstream side of the switching element 15F. The downstream side of the solenoid valve 6b is connected to the ground 18G.

[0020] The solenoid valve 6a and the solenoid valve 6b are various solenoid valves provided in the work machine 1, for example, for switching between high and low traveling speeds of the work machine 1, for switching the relief pressure of an attachment, and for switching engagement or release of a swing parking brake of the work machine 1.

[0021] The solenoid valve 6c performs opening / closing operations, direction switching operations and the like by electric power supplied from the battery 4. The upstream side of the solenoid valve 6c is connected to the downstream side of the switching element 13F. The downstream side of the solenoid valve 6c is connected to the ground 16G. The solenoid valve 6c is connected to the power source 2. The solenoid valve 6c controls the power source 2. More specifically, the solenoid valve 6c controls the tilt angle of the swash plate of the variable displacement pump 2P based on a control signal from the control unit 20.

[0022] [Controller] The controller 10 is a controller for the work machine 1. The controller 10 outputs signals for controlling the work implement, the lower traveling structure and the upper revolving structure of the work machine 1. The controller 10 outputs a drive control signal to the power source 2 to control the power source 2. When an abnormality occurs inside the controller 10, the controller 10 outputs a shutoff control signal to shut off the supply of electric power from the battery 4. When the controller 10 determines that an abnormality has occurred in a power supply circuit connecting the controller 10 and the solenoid valve 6, the controller 10 outputs a command to control the power source 2 so as to restrict the operation of the work implement. The controller 10 includes the control unit 20. An electric signal line 101, an electric signal line 103, an electric signal line 104, and an electric signal line 105 are electrically connected to the controller 10. When the main controller 10 determines that an abnormality has occurred in the power supply circuit connecting the controller 10 and the solenoid valve 6, the main controller 10 may output a command to control the power source 2 so as to restrict the operations of the work implement, the lower traveling structure and the upper revolving structure.

[0023] In this disclosure, if the controller 10 determines that an abnormality has occurred in the power supply circuit connecting the controller 10 and the solenoid valve 6, it outputs a command to control the rotational speed of the engine 2E to decrease. In this disclosure, if the controller 10 determines that an abnormality has occurred in at least one of the power supply circuits connecting the controller 10 and each of the solenoid valves 6a, 6b, and 6c, it outputs a command to the power source controller 30 to control the rotational speed of the engine 2E to, for example, a low idle speed.

[0024] In this disclosure, if the controller 10 determines that an abnormality has occurred in the power supply circuit connecting the controller 10 and the solenoid valve 6, it outputs a command to control the variable displacement pump 2P to reduce its discharge rate. In this disclosure, if the controller 10 determines that an abnormality has occurred in at least one of the power supply circuits connecting the controller 10 and each of the solenoid valves 6a, 6b, and 6c, it outputs a command to control the variable displacement pump 2P to minimize its discharge rate, for example.

[0025] In this disclosure, the controller 10 determines an abnormality in at least one of the power supply circuits connecting the controller 10 to each of the solenoid valves 6a, 6b, and 6c when the key of the work machine 1 is operated. When the key of the work machine 1 is operated, for example, when the key is turned ON or when the key is turned OFF. When the key is turned ON, it is the start of work for the work machine 1. When the key is turned OFF, it is the end of work for the work machine 1.

[0026] The controller 10 includes switching elements 11F, 13F, 14F, and 15F, diodes 11D, 13D, 14D, 15D, 16D, 17D, and 18D, and grounds 16G, 17G, and 18G.

[0027] The switching elements 11F, 13F, 14F, and 15F switch between a conductive state and a non-conductive state of the circuit based on commands from the control unit 20. The switching elements 11F, 13F, 14F, and 15F are, for example, FETs (Field Effect Transistors) or transistors.

[0028] The switching element 11F is provided to supply or interrupt power from the battery 4. The switching element 11F is located between the downstream side of the battery 4 and the upstream side of the solenoid valve 6. The gate of the switching element 11F is connected to the control unit 20. When the switching element 11F is conductive, power is supplied to the downstream side of the electrical signal line 101. When the switching element 11F is non-conductive, the power supply to the downstream side of the electrical signal line 101 is interrupted.

[0029] More specifically, when an ON electrical signal is input to the switching element 11F as a switching signal, power can be supplied to the solenoid valve 6. When an OFF electrical signal is input to the switching element 11F as a switching signal, the power supply to the solenoid valve 6 is cut off.

[0030] The switching element 13F is provided to drive the solenoid valve 6c. The switching element 13F is provided to switch the power supply to the solenoid valve 6c in response to a command from the control unit 20. The switching element 13F is located between terminal 101a and ground 16G. The gate of the switching element 13F is connected to the control unit 20. If an abnormality such as a fault occurs, the switching element 13F becomes non-conductive and cuts off the power supply to the solenoid valve 6c.

[0031] The switching element 14F is provided to drive the solenoid valve 6a. The switching element 14F is provided to switch the power supply to the solenoid valve 6a in response to a command from the control unit 20. The switching element 14F is located between terminal 101b and ground 17G. The gate of the switching element 14F is connected to the control unit 20. If an abnormality such as a ceiling fault occurs, the switching element 14F becomes non-conductive and cuts off the power supply to the solenoid valve 6a.

[0032] The switching element 15F is provided to drive the solenoid valve 6b. The switching element 15F is provided to switch the power supply to the solenoid valve 6b in response to a command from the control unit 20. The switching element 15F is located between terminal 101c and ground 18G. The gate of the switching element 15F is connected to the control unit 20. If an abnormality such as a ceiling fault occurs, the switching element 15F becomes non-conductive and cuts off the power supply to the solenoid valve 6b.

[0033] The electrical signal line 101 electrically connects the battery 4 and the controller 10. The electrical signal line 101 also electrically connects the battery 4 and the control unit 20. A switching element 11F is connected to the electrical signal line 101 from the battery 4 side.

[0034] Terminal 101a electrically connects the downstream side of switching element 11F to the upstream side of switching element 13F. Terminal 101b electrically connects the downstream side of switching element 11F to the upstream side of switching element 14F. Terminal 101c electrically connects the downstream side of switching element 11F to the upstream side of switching element 15F.

[0035] The electrical signal line 101i electrically connects the downstream side of the battery 4 and the upstream side of the switching element 11F to the control unit 20.

[0036] The electrical signal line 101j electrically connects the downstream side of the switching element 11F and the upstream side of terminal 101a to the control unit 20.

[0037] The electrical signal line 102 electrically connects the power source 2 and the power source controller 30.

[0038] The electrical signal line 103 connects the downstream side of the switching element 13F to the upstream side of the solenoid valve 6c. The electrical signal line 103 electrically connects the controller 10 and the solenoid valve 6c. The electrical signal line 103 is a power supply circuit connecting the controller 10 and the solenoid valve 6c.

[0039] The electrical signal line 104 connects the downstream side of the switching element 14F to the upstream side of the solenoid valve 6a. The electrical signal line 104 electrically connects the controller 10 and the solenoid valve 6a. The electrical signal line 104 is a power supply circuit connecting the controller 10 and the solenoid valve 6a.

[0040] The electrical signal line 105 connects the downstream side of the switching element 15F to the upstream side of the solenoid valve 6b. The electrical signal line 105 electrically connects the controller 10 and the solenoid valve 6b. The electrical signal line 105 is a power supply circuit connecting the controller 10 and the solenoid valve 6b.

[0041] The electrical signal line 106 electrically connects the downstream side of the switching element 13F to the control unit 20. The electrical signal line 106 is electrically connected to the electrical signal line 103.

[0042] The electrical signal line 107 electrically connects the downstream side of the switching element 14F to the control unit 20. The electrical signal line 107 is electrically connected to the electrical signal line 104.

[0043] The electrical signal line 108 electrically connects the downstream side of the switching element 15F to the control unit 20. The electrical signal line 108 is electrically connected to the electrical signal line 105.

[0044] [Control Unit] The control unit 20 is powered by the battery 4. The control unit 20 receives signals from the operating device 5. The control unit 20 outputs signals to the power source controller 30. The control unit 20 includes an abnormality monitoring unit 21, a shut-off control unit 22, a drive control unit 23, and an output unit 24.

[0045] The abnormality monitoring unit 21 monitors for abnormalities such as faults inside the controller 10. For example, the abnormality monitoring unit 21 monitors for failures of switching elements 11F, 13F, 14F, and 15F located inside the controller 10. Any known method can be used to determine the failure of a switching element.

[0046] The abnormality monitoring unit 21 monitors for abnormalities such as faults in the power supply circuit outside the controller 10. The abnormality monitoring unit 21 monitors for the occurrence of abnormalities such as faults in the power supply circuit connecting the controller 10 and the solenoid valve 6. An example of a fault is when the electrical signal line 101 between the controller 10 and the battery 4 and the electrical signal line 103 of the solenoid valve 6c become electrically conductive, as shown by the dashed line A in Figure 1. The abnormality monitoring unit 21 monitors the voltage between the controller 10 and the solenoid valves 6a, 6b, and 6c. The abnormality monitoring unit 21 determines that an abnormality has occurred if, while the power supply from the power supply circuit's electrical signal lines 103, 104, and 105 to the solenoid valves 6a, 6b, or 6c is cut off by the control unit 20, a voltage above a threshold is applied to the solenoid valves 6a, 6b, or 6c. The abnormality monitoring unit 21 determines that an abnormality such as a short circuit has occurred when it detects that the feedback voltage is above a threshold value while the power supply from the power supply circuit, consisting of electrical signal lines 103, 104, and 105, to the solenoid valve 6a, 6b, or 6c is cut off by the control unit 20. The feedback voltage may be detected, for example, by converting the current flowing through the electrical signal line 103 into a voltage using the controller 10, and then inputting the converted voltage value into the CPU for evaluation.

[0047] The monitoring of abnormalities in the external power supply circuit of the controller 10 by the abnormality monitoring unit 21 may be performed as a daily process. In this disclosure, the abnormality monitoring unit 21 monitors for the occurrence of abnormalities such as a short circuit in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to solenoid valves 6a, 6b, and 6c, respectively, when the key of the work machine 1 is operated. When the key of the work machine 1 is operated, for example, when the key is turned ON or when the key is turned OFF. When the key is turned ON, it is when work is started on the work machine 1. This allows for the detection of abnormalities in the work machine 1 at the start of work. When the key is turned OFF, it is when work is finished on the work machine 1. This allows for the detection of abnormalities in the work machine 1 at the end of work. In this case, it is possible to request inspection and repair of the work machine 1 by a service technician performing maintenance before the start of the next work.

[0048] The interruption control unit 22 controls the power supply from the battery 4. More specifically, the interruption control unit 22 switches the switching element 11F on and off. When the abnormality monitoring unit 21 detects an abnormality such as a fault inside the controller 10, the interruption control unit 22 outputs an off electrical signal as a switching signal to the switching element 11F in order to interrupt the power supply from the battery 4. If the abnormality monitoring unit 21 does not detect an abnormality such as a fault inside the controller 10, the interruption control unit 22 outputs an on electrical signal as a switching signal to the switching element 11F.

[0049] The drive control unit 23 controls the solenoid valve 6a. More specifically, the drive control unit 23 switches the switching element 14F on and off. When the abnormality monitoring unit 21 detects an abnormality such as a fault inside the controller 10, the drive control unit 23 outputs an off electrical signal as a switching signal to the switching element 14F in order to shut off the solenoid valve 6a.

[0050] The drive control unit 23 controls the solenoid valve 6b. More specifically, the drive control unit 23 switches the switching element 15F on and off. When the abnormality monitoring unit 21 detects an abnormality such as a fault inside the controller 10, the drive control unit 23 outputs an off electrical signal as a switching signal to the switching element 15F in order to shut off the solenoid valve 6b.

[0051] The drive control unit 23 controls the solenoid valve 6c. More specifically, the drive control unit 23 switches the switching element 13F on and off. When the abnormality monitoring unit 21 detects an abnormality such as a fault inside the controller 10, the drive control unit 23 outputs an off electrical signal as a switching signal to the switching element 13F in order to shut off the solenoid valve 6c.

[0052] The drive control unit 23 controls at least one of the solenoid valves 6a, 6b, and 6c based on the control signal output from the operating device 5.

[0053] The output unit 24 outputs a command to the power source controller 30 to control the power source 2 in order to suppress it. More specifically, the output unit 24 outputs a command to the power source controller 30 to control the power source 2 in order to limit the operation of the work machine when the abnormality monitoring unit 21 determines that an abnormality has occurred in the power supply circuit connecting the controller 10 and the solenoid valve 6. In this disclosure, the output unit 24 outputs a command to the power source controller 30 to control the power source 2 in order to limit the operation of the work machine, the lower traveling body and the upper rotating body when the abnormality monitoring unit 21 determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are the power supply circuits connecting the controller 10 and the solenoid valves 6a, 6b, and 6c, respectively.

[0054] In this disclosure, the output unit 24 outputs a command to control the rotational speed of the engine 2E to decrease if it determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to each of the solenoid valves 6a, 6b, and 6c. In this disclosure, the output unit 24 outputs a command to control the rotational speed of the engine 2E to a low idle level, for example, if the abnormality monitoring unit 21 determines that an abnormality has occurred in at least one of the power supply circuits connecting the controller 10 to each of the solenoid valves 6a, 6b, and 6c.

[0055] In this disclosure, the output unit 24 outputs a command to control the variable displacement pump 2P to reduce its discharge rate when it determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to each of the solenoid valves 6a, 6b, and 6c. In this disclosure, the output unit 24 outputs a command to control the variable displacement pump 2P to minimize its discharge rate when the abnormality monitoring unit 21 determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to each of the solenoid valves 6a, 6b, and 6c.

[0056] [Power source controller] The power source controller 30 is a controller that controls the power source 2. The power source controller 30 is electrically connected to the control unit 20 and the power source 2. An electrical signal line 102 is electrically connected to the power source controller 30. The power source controller 30 outputs a control signal that controls the power source 2. A power source controller 30 is provided for each power source 2. For example, if the power source 2 is an engine 2E, the power source controller 30 is an engine controller. For example, if the power source 2 is a generator, the power source controller 30 is a generator controller. For example, if the power source 2 is a fuel cell, the power source controller 30 is a fuel cell controller.

[0057] When the power source controller 30 receives a command from the output unit 24 of the control unit 20, it outputs a control signal to the power source 2 to suppress the power source 2. If the abnormality monitoring unit 21 determines that an abnormality has occurred in the power supply circuit connecting the controller 10 and the solenoid valve 6, a command is input to the power source controller 30 from the output unit 24.

[0058] The power source controller 30 outputs a control signal to the power source 2 that controls the operation of the work machine in order to limit the operation of the work machine, based on a command from the output unit 24.

[0059] In this disclosure, the power source controller 30 outputs a control signal to the power source 2 to reduce the rotational speed of the engine 2E if the abnormality monitoring unit 21 of the control unit 20 determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to the solenoid valves 6a, 6b, and 6c, respectively. In this disclosure, the power source controller 30 outputs a control signal to the power source 2 to control the rotational speed of the engine 2E to a level equivalent to low idle, based on a command from the output unit 24.

[0060] In this disclosure, the power source controller 30 outputs a control signal to the power source 2 to reduce the discharge amount of the variable displacement pump 2P when the abnormality monitoring unit 21 of the control unit 20 determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to the solenoid valves 6a, 6b, and 6c, respectively. In this disclosure, the power source controller 30 outputs a control signal to the power source 2 to control the discharge amount from the variable displacement pump 2P to the minimum, based on a command from the output unit 24.

[0061] The power source controller 30 outputs a control signal to the power source 2 that controls the operation of the work implement, the lower traveling body, and the upper rotating body, based on a command from the output unit 24.

[0062] [Computer System] Figure 2 is a block diagram showing a computer system 1000 according to the first embodiment. The controller 60 described above includes the computer system 1000. The computer system 1000 has a processor 1001 such as a CPU (Central Processing Unit), a main memory 1002 including non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory), a storage 1003, and an interface 1004 including input / output circuits. The functions of the controller 10 described above are stored as a program in the storage 1003. The processor 1001 reads the program from the storage 1003, loads it into the main memory 1002, and executes the above-described processing according to the program. The program may be distributed to the computer system 1000 via a network.

[0063] [Control processing for working machinery] Next, the procedure for processing in the embodiment will be described with reference to the flowchart shown in Figure 3. Figure 3 is a flowchart of the control method performed by the controller 10 of the work machine 1 according to the first embodiment. In this disclosure, the processing shown in Figure 3 is executed when the key of the work machine 1 is turned ON or turned OFF.

[0064] The abnormality monitoring unit 21 determines whether there is an abnormality in the power supply circuit connecting the controller 10, which is the power supply, and the solenoid valve 6 (step S101). More specifically, the abnormality monitoring unit 21 determines that an abnormality has occurred if, while the power supply from the power supply circuit, consisting of electrical signal lines 103, 104, and 105, to the solenoid valve 6a, solenoid valve 6b, or solenoid valve 6c is cut off by the control unit 20, a voltage above a threshold is applied to the solenoid valve 6a, solenoid valve 6b, or solenoid valve 6c. The swivel control unit 11 determines that an abnormality has occurred if, while the power supply from the power supply circuit, consisting of electrical signal lines 103, 104, and 105, to the solenoid valve 6a, solenoid valve 6b, or solenoid valve 6c is cut off by the control unit 20, the feedback voltage is above a threshold. If the abnormality monitoring unit 21 determines that there is an abnormality (Yes in step S101), it proceeds to step S102. If the abnormality monitoring unit 21 determines that there is no abnormality (No in step S101), it terminates the process.

[0065] If an abnormality is detected (Yes in step S101), the output unit 24 outputs a command to the power source controller 30 to control the power source 2. More specifically, the output unit 24 outputs a command to control the engine 2E so that its rotational speed is equivalent to low idle. The output unit 24 also outputs a command to control the variable displacement pump 2P so that its discharge amount is minimized.

[0066] When a command to control the power source 2 is output from the output unit 24 to the power source controller 30, the operator is notified that an abnormality has occurred in the power circuit outside the controller 10. For example, a message image indicating the abnormality in the power circuit outside the controller 10 is output to a monitor installed in the operator's cab of the work machine 1. For example, a buzzer installed in the operator's cab of the work machine 1 sounds to notify the operator of the abnormality in the power circuit outside the controller 10. The operator can then confirm that the operation of the work machine, lower traveling body, and upper rotating body of the work machine 1 is restricted.

[0067] Thus, in this disclosure, if the controller 10 determines that an abnormality has occurred in the power supply circuit outside the controller 10, in other words, the power supply circuit connecting the controller 10 and the solenoid valve 6, it outputs a command to control the power source 2 to restrict the operation of the work machine, the lower traveling body, and the upper slewing body. The work machine 1's operation is restricted to the same extent as when it is idling low, and operations such as excavation are restricted. The operator can move the work machine 1 to a safe location.

[0068] [effect] As described above, in this disclosure, if it is determined that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to solenoid valves 6a, 6b, and 6c respectively, a command is output to control the power source 2 to restrict the operation of the work implement, lower traveling body, and upper slewing body. In this disclosure, if an abnormality occurs in the power supply circuit outside the controller 10, the power source 2 can be controlled to restrict the operation of the work implement, lower traveling body, and upper slewing body. Thus, according to this disclosure, in addition to cases where an abnormality occurs inside the controller 10, an abnormality occurs in the power supply circuit outside the controller 10, the work implement 1 can be controlled to further enhance safety.

[0069] In this disclosure, if the controller 10 determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to solenoid valves 6a, 6b, and 6c respectively, it outputs a command to control the rotational speed of the engine 2E to low idle. According to this disclosure, by suppressing the rotational speed of the engine 2E, the operation of the work equipment, the lower traveling body, and the upper slewing body can be restricted.

[0070] In this disclosure, if the controller 10 determines that an abnormality has occurred in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to solenoid valves 6a, 6b, and 6c respectively, it outputs a command to control the discharge amount from the variable displacement pump 2P to the minimum. According to this disclosure, by limiting the discharge amount from the variable displacement pump 2P, the operation of the work machine, the lower traveling body, and the upper slewing body can be restricted.

[0071] This disclosure describes how, when the key of the work machine 1 is operated, an abnormality in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to solenoid valves 6a, 6b, and 6c respectively, can be determined. According to this disclosure, an abnormality in the power supply circuit outside the controller 10 can be determined at the start or end of work of the work machine 1. If an abnormality is detected at the start of work, work such as excavation by the work machine 1 can be prevented. In this case, malfunction of the work machine 1 during work can be suppressed. If an abnormality is detected at the end of work, inspection and repair of the work machine 1 by a service technician performing maintenance can be requested before the start of the next work.

[0072] In this disclosure, the notification unit notifies the operator if an abnormality occurs in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to each of the solenoid valves 6a, 6b, and 6c. According to this disclosure, the operator can confirm that the operation of the work machine, lower traveling body, and upper rotating body of the work machine 1 is restricted.

[0073] (Second Embodiment) Figure 4 is a schematic block diagram of the work machine 1A according to the second embodiment. In the following description, components that are the same as or equivalent to those in the above-described embodiment are denoted by the same reference numerals, and their descriptions are simplified or omitted.

[0074] The work machine 1A includes a controller 10, a power source controller 30A, and a secondary controller 40A.

[0075] The control unit 20 of the controller 10 includes an abnormality monitoring unit 21, a circuit breaker control unit 22, and a drive control unit 23. The abnormality monitoring unit 21 has the function of monitoring abnormalities such as faults inside the controller 10, which is one of the functions of the abnormality monitoring unit 21 of the first embodiment. The circuit breaker control unit 22 and the drive control unit 23 have the same functions as in the first embodiment.

[0076] The power source controller 30A is electrically connected to the secondary controller 40A and the power source 2. Based on the control signals from the secondary controller 40A, the power source controller 30A outputs a control signal to control the power source 2.

[0077] [Secondary Controller] The secondary controller 40A has an abnormality monitoring unit 41A and an output unit 42A. The secondary controller 40A is electrically connected to solenoid valve 6aA via electrical signal line 107A connected to electrical signal line 104. The secondary controller 40A is electrically connected to solenoid valve 6bA via electrical signal line 108A connected to electrical signal line 105. The secondary controller 40A is electrically connected to solenoid valve 6cA via electrical signal line 106A connected to electrical signal line 103. The secondary controller 40A receives signals from solenoid valves 6aA, 6bA and 6cA.

[0078] The abnormality monitoring unit 41A has the function of monitoring abnormalities in the power supply circuit outside the controller 10, which is one of the functions of the abnormality monitoring unit 21 in the first embodiment. In this disclosure, the abnormality monitoring unit 41A determines an abnormality in at least one of the electrical signal lines 103, 104, and 105, which are power supply circuits connecting the controller 10 to solenoid valves 6aA, 6bA, and 6cA, respectively.

[0079] The output unit 42A has the same function as the output unit 24 of the first embodiment.

[0080] As described above, in this disclosure, the secondary controller 40A can detect when an abnormality occurs in the power supply circuit outside the controller 10. According to this disclosure, in addition to when an abnormality occurs inside the controller 10, the working machine 1A can be controlled to further enhance safety when an abnormality occurs in the power supply circuit outside the controller 10. [Explanation of Symbols]

[0081] 1...Working machine, 2...Power source, 2E...Engine, 2P...Variable displacement pump, 2X...Drive shaft, 3...Hydraulic actuator, 4...Battery, 5...Operating device, 6,6a,6b,6c...Solenoid valve, 10...Controller (1st controller), 11D,13D,14D,15D,16D,17D,18D...Diode, 11F,13F,14F,15F...Switching element, 16G,17G,18G...Ground, 20...Control unit, 21...Anomaly monitoring unit, 22...Shut-off control unit, 23...Drive control unit, 24...Output unit, 30...Power source controller, 101,101i,101j,102,103,104,105,106,107,108...Electrical signal line, 101a,101b,101c...Terminal.

Claims

1. A work machine having a work mechanism, An electric motor that outputs driving force to operate the aforementioned work machine, Controller and A solenoid valve controlled by the aforementioned controller, Equipped with, If the controller determines that an abnormality has occurred in the power supply circuit connecting the controller and the solenoid valve, it outputs a command to control the electric motor to reduce the total amount of hydraulic fluid supplied to the hydraulic actuator of the work machine in order to limit the operation of the work machine. A type of machinery used for industrial work.

2. The controller determines an abnormality in the power supply circuit between the controller and the solenoid valve when the work machine starts operation. The work machine according to claim 1.

3. The controller determines an abnormality in the power supply circuit between the controller and the solenoid valve when the work of the work machine is completed. The work machine according to claim 1.

4. A notification unit that notifies that an abnormality has occurred in the power supply circuit connecting the controller and the solenoid valve. The work machine according to claim 1, comprising:

5. A control method for a work machine having a work machine and an electric motor that outputs a driving force for operating the work machine, If it is determined that an abnormality has occurred in the power supply circuit connecting the controller for controlling the solenoid valve and the solenoid valve, a command is output to control the electric motor to reduce the total amount of hydraulic fluid supplied to the hydraulic actuator of the work machine in order to limit the operation of the work machine. A method for controlling industrial machinery.

Images