Working machinery

Abstract

To provide a work machine allowing energy consumption to be reduced while preventing machine motion through no intention of an operator.SOLUTION: A motor-driven shovel 1 is provided with a controller 2, a motor 3 of a driving source, a key switch 4, a lever lock 5, a grip switch 6, and an operation lever 60. The key switch 4 accepts an on operation and an off operation of the controller 2. The lever lock 5 accepts a lock operation invalidating a lever operation and a lock release operation validating the lever operation with the operation lever 60. The grip switch 6 accepts a start operation and a stop operation of the motor 3. The controller 2, in a state of starting up through the on-operation accepted by key switch 4, starts the motor 3 when determining the lock release operation is accepted by the lever lock 5 and the start operation is accepted by the grip switch 6.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a work machine that controls the start and stop of a drive source.

Background Art

[0002] Conventionally, in the field of construction machinery, a hydraulic excavator that suppresses the operation of a work machine or the like unintended by an operator has been proposed (see, for example, Patent Document 1).

[0003] In Patent Document 1, after the start switch (27) is operated and the engine (7) starts, when the lock lever (25) is rotated to the unlock position (unlocked position), the lock valve (43) becomes ON, and the pilot pressure is supplied to the switching valve (42). However, since the cutoff switch (29) is not operated, the switching valve (42) is in the OFF state, and the operation levers (21, 22) and the pilot valve (41) are also in the N position. Therefore, the actuator remains stopped (state (b) in FIG. 4 of Patent Document 1).

[0004] In the above state (b), when the cutoff switch (29) is operated and the switching valve (42) becomes ON, the pilot pressure is supplied to the pilot valve (41). However, since the operation levers (21, 22) are in the N position, the actuator remains stopped (state (c) in FIG. 4 of Patent Document 1).

[0005] In the above state (c), when the driver operates the operation levers (21, 22) to operate the pilot valve (41), the pilot pressure is supplied to the actuator side. As a result, the actuator can be operated (state (d) in FIG. 4 of Patent Document 1).

[0006] Also, in the field of construction machinery, a construction machine capable of suppressing the consumption of battery power has been proposed (see, for example, Patent Document 2).

[0007] In Patent Document 2, when the key switch (28) is operated from the OFF position to the START position, the power supply for the inverter device (30), etc., is turned ON (S100 in Figure 4 of Patent Document 2).

[0008] Next, the main control unit (51) and the fan control unit (52) determine whether or not a signal has been received from the lock switch (43) (S110 in Figure 4 of Patent Document 2). If it is determined that the lock lever (25) is in the unlocked position, the fan control unit (52) drives the electric motor (50) for the fan to rotate the cooling fan (49) (S140 in Figure 4 of Patent Document 2).

[0009] During the initial startup of the hydraulic excavator, and while the operator is operating any of the control devices (NO in S150 of Figure 4 in Patent Document 2), the main electric motor (31) is driven (S160 of Figure 4 in Patent Document 2). [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2013-36270 [Patent Document 2] Japanese Patent Publication No. 2011-256608 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] In the aforementioned Patent Document 1, the engine (7) starts immediately when the start switch (27) is operated. Therefore, the engine (7) remains idling until the cut-off switch (29) is manually operated after the engine (7) has started, and until the operating levers (21, 22) are operated. Consequently, Patent Document 1 has the problem of consuming more energy than necessary.

[0012] Furthermore, in Patent Document 2, if the operator unconsciously touches the operating lever when the lock lever (25) is released, there is a possibility that the machine may perform an action unintended by the operator, and therefore it cannot necessarily be said to be safe.

[0013] Therefore, the present invention aims to provide a work machine that can reduce energy consumption while avoiding unintended machine operation by the operator. [Means for solving the problem]

[0014] To achieve the above objective, the present invention provides a work machine comprising: a drive source; a controller for starting or stopping the drive source; a first switch for receiving an ON operation to activate the controller and an OFF operation to stop the controller; an operating lever for operating an object to be operated; a lever lock for receiving a lock operation to disable the lever operation by the operating lever and an unlock operation to enable the lever operation; and a second switch for receiving a start operation to activate the drive source and a stop operation to stop the drive source, wherein the controller starts the drive source when it determines that the lever lock has received an unlock operation and the second switch has received a start operation while the first switch has received the ON operation and the controller is activated.

[0015] Here, it is preferable that the controller stops the drive source in any of the following cases while the drive source is in operation: when it determines that the first switch has received the off operation, when it determines that the lever lock has received the lock operation, or when it determines that the second switch has received the stop operation.

[0016] Further, the controller determines that the lock operation has been received by the lever lock, and after stopping the drive source, even if it is determined that the unlock operation has been received by the lever lock, the drive source is not started until it is determined that the start operation has been received by the second switch. It is preferable to start the drive source when it is determined that the unlock operation has been received by the lever lock and further it is determined that the start operation has been received by the second switch.

Advantages of the Invention

[0017] According to the present invention, even if an unlock operation is received by the lever lock, the drive source does not start unless a start operation is received by the second switch. Therefore, even if the operator accidentally touches the operation lever during the unlock operation, the machine does not operate, so it is possible to avoid unintended machine operation by the operator. Further, the drive source does not operate unless all of the on operation to the first switch, the unlock operation to the lever lock, and the start operation to the second switch are received, so it is possible to reduce energy consumption.

Brief Description of the Drawings

[0018] [Figure 1] System configuration diagram of an electric excavator (working machine) according to an embodiment of the present invention. [Figure 2] Plan view of the cab of the electric excavator as seen from above. [Figure 3] Perspective view showing a part of the front right side of the cab. [Figure 4] Perspective view showing a part of the front left side of the cab. [Figure 5] Flowchart showing the procedure for starting an electric motor (drive source). [Figure 6] Flowchart showing the procedure for restarting a stopped electric motor (drive source). [Figure 7] System configuration diagram of a hydraulic excavator (working machine) according to a modified example.

Embodiments of the Invention

[0019] <1. Embodiment> The working machine according to an embodiment of the present invention will be described based on FIGS. 1 to 6. Hereinafter, as an example of the working machine, the electric excavator 1 shown in FIG. 1 will be exemplified.

[0020] As shown in FIG. 1, the electric excavator 1 mainly includes a controller 2, an electric motor 3, a key switch 4, a lever lock 5, a grip switch 6, and left and right operation levers 60. As shown in FIG. 2, the operation lever 60 includes a left operation lever 60L and a right operation lever 60R.

[0021] The electric excavator 1 also includes a battery 31 that supplies power to the electric motor 3, a hydraulic pump 33 that supplies pressure oil to a hydraulic actuator (operation target) not shown, a solenoid valve 35, a control valve 37, and the like.

[0022] The controller 2 is a device that controls the operation of the electric excavator 1 such as starting and stopping of the electric motor 3.

[0023] The electric motor 3 is driven by the power supplied from the battery 31 and is a drive source of the electric excavator 1 that drives the hydraulic pump 33 and a pilot pump not shown. The hydraulic pump 33 is a variable displacement type hydraulic pump and includes a regulator for adjusting the pump capacity That is, the pump capacity of the hydraulic pump 33 is adjusted by a pump regulator based on a pump capacity command output from the controller 2.

[0024] As shown in FIGS. 2 to 4, the operation levers 60L and 60R are arranged on the front side of a console arranged on both the left and right sides of the driver's seat. The operation levers 60L and 60R are configured as electric lever devices. The operation amounts (tilting amounts) input to the operation levers 60L and 60R are acquired by sensors. The measurement signals of the operation amounts acquired by the sensors are transmitted to the controller 2.

[0025] The solenoid valve 35 uses the discharge pressure from the pilot pump as the base pressure and generates pilot pressure in accordance with the drive signal transmitted from the controller 2, and outputs the pilot pressure to the control valve 37. The drive signal is set to a value corresponding to the amount of operation received by the operating levers 60L and 60R, which are acquired by the controller 2.

[0026] As shown in Figures 2 and 3, the key switch 4 is a rotary physical key and is located on the right side of the driver's seat, behind the right-side operating lever 60R. The key switch 4 is configured to rotate from the off position to the on position and from the on position to the off position in response to manual operation by the operator.

[0027] The system is configured such that when the key switch 4 is rotated from the off position to the on position, the electrical components, including the controller 2, are activated (powered on). Conversely, when the key switch 4 is rotated from the on position to the off position, the electrical components, including the controller 2, are deactivated (powered off).

[0028] In other words, the key switch 4 functions as a switch that accepts an ON operation to activate (power on) the electrical components, including the controller 2, and an OFF operation to stop (deactivate) the electrical components. The key switch 4 is an example of the "first switch" according to the present invention. A push-type switch that accepts ON and OFF operations may be used as the "first switch".

[0029] The lever lock 5 is a safety lever designed to prevent the actuator from operating against the operator's intent when the machine is not in operation.

[0030] As shown in Figures 2 and 4, the lever lock 5 is located on the left side of the driver's seat, in front of and below the left operating lever 60L. The lever lock 5 moves to the locked position when pulled upward (raised) by the operator, and to the unlocked position when lowered.

[0031] When the operator pulls (lifts) the lever lock 5 from the unlocked position to the locked position, the controller 2 stops outputting a drive signal to the solenoid valve 35. Alternatively, the supply of pilot pressure to the solenoid valve 35 is cut off. As a result, lever operation by the operating levers 60L and 60R becomes ineffective, and even if the operating levers 60L and 60R are operated, the controller 2 does not output a drive signal to the control valve 37.

[0032] Conversely, when the operator lowers the lever lock 5, moving it from the locked position to the unlocked position, the controller 2 outputs a drive signal to the solenoid valve 35, and the supply of pilot pressure to the solenoid valve 35 is permitted. As a result, lever operation by the operating levers 60L and 60R becomes effective, and the controller 2 outputs a drive signal to the control valve 37 in accordance with the operation received by the operating levers 60L and 60R.

[0033] In other words, the lever lock 5 functions as an operable member that receives a lock operation to disable the lever operation by the operating levers 60L and 60R, and a unlock operation to enable the said lever operation. Note that the lever lock 5 is an example of a "lever lock" according to the present invention.

[0034] The grip switch 6 is a switch for starting or stopping the electric motor 3.

[0035] As shown in Figures 2 and 3, the grip switch 6 is configured as a push-type switch located at the upper end of the right-side operating lever 60R. By pressing the grip switch 6, the electric motor 3 can be started or stopped. In this embodiment, the grip switch 6 accepts a push operation while the electric motor 3 is stopped as a start operation for the electric motor 3. Furthermore, the grip switch 6 accepts a push operation while the electric motor 3 is running as a stop operation for the electric motor 3. Note that the grip switch 6 is an example of the "second switch" according to the present invention.

[0036] Next, referring to the flowchart in Figure 5, we will explain the procedure for starting the electric motor 3, which is the drive source.

[0037] First, when the operator rotates the key switch 4 from the off position to the on position, the electric excavator 1 activates (powers on) the electrical components, including the controller 2 (step S11).

[0038] Next, the controller 2 determines whether the lever lock 5 has been operated from the locked position to the unlocked position (step S12). In other words, the controller 2 determines whether an unlock operation that enables lever operation by the operating levers 60L and 60R has been received by the lever lock 5.

[0039] If it is determined that an unlock operation has been received by the lever lock 5 (YES in step S12), the process proceeds to step S13. In step S13, the controller 2 determines whether or not the grip switch 6 has been pressed. In other words, the controller 2 determines whether or not an ignition operation has been received by the grip switch 6.

[0040] When the grip switch 6 determines that a start operation has been received (YES in step S13), the controller 2 starts the electric motor 3, which is the drive source (step S14).

[0041] When the electric motor 3 is started (step S14), the pump regulator minimizes the tilt angle of the hydraulic pump 33 and discharges pressurized oil at the lowest flow rate from the hydraulic pump 33. At the same time, the pilot pump is driven and supplied to the solenoid valve 35. In this state, when the operating lever 60 is operated and displaced from the neutral position, the control valve 37 supplies pressurized oil from the hydraulic pump 33 to the hydraulic actuator (the object being operated). Furthermore, the controller 2 outputs a pump capacity command so that the pump capacity of the hydraulic pump 33 increases as the amount of displacement of the operating lever 60 from the neutral position increases, thereby driving the hydraulic actuator (the object being operated).

[0042] Next, referring to the flowchart in Figure 6, we will explain the procedure for restarting the electric motor 3, which has stopped due to the locking operation of the lever lock 5.

[0043] First, in step S31, it is determined whether the lever lock 5 was moved from the unlocked position to the locked position while the electric motor 3 was being driven. In other words, the controller 2 determines whether a lock operation that invalidates the lever operation by the operating levers 60L and 60R has been received by the lever lock 5.

[0044] If it is determined that a lock operation has been received by the lever lock 5 (YES in step S31), the process proceeds to step S32. In step S32, the controller 2 stops the electric motor 3, which is the drive source.

[0045] Next, the controller 2 determines whether the lever lock 5 has been operated again from the locked position to the unlocked position (step S33). In other words, the controller 2 determines whether the unlock operation described above has been accepted again for the lever lock 5.

[0046] If it is determined that a lock release operation has been received by the lever lock 5 (YES in step S33), the process proceeds to step S34. However, even if it is determined that a lock release operation has been received by the lever lock 5, the controller 2 does not yet restart the electric motor 3, which is the drive source.

[0047] In step S34, the controller 2 determines whether or not the grip switch 6 has been pressed. In other words, the controller 2 determines whether or not a start operation has been received by the grip switch 6. At this point, the electric motor 3 is stopped, so when the grip switch 6 is pushed by the operator, the controller 2 receives the push operation as a start operation.

[0048] When the grip switch 6 determines that a start operation has been received (YES in step S34), the controller 2 restarts the electric motor 3, which is the drive source.

[0049] Furthermore, the flowchart in Figure 6 illustrates the case where, while the electric motor 3 is being driven, the lever lock 5 is moved from the unlocked position to the locked position (YES in step S31), and the controller 2 stops the electric motor 3 (step S32).

[0050] Similarly, if the key switch 4 is turned off or the grip switch 6 is turned on while the electric motor 3 is running, the controller 2 will also stop the electric motor 3.

[0051] In other words, while the electric motor 3 is running, the controller 2 stops the electric motor 3, which is the drive source, if an off operation is received by the key switch 4, a lock operation is received by the lever lock 5, or a stop operation is received by the grip switch 6.

[0052] According to the embodiment described above, even if a lock release operation is received by the lever lock 5, the electric motor 3, which is the drive source, will not start unless a start operation is received by the grip switch 6. Therefore, even if the operator unconsciously touches the operating lever 60 (60L, 60R) during the lock release operation, the machine will not operate, thus preventing unintended machine operation by the operator.

[0053] Furthermore, since the electric motor 3, which is the drive source, will not operate unless all three operations—the ON operation of the key switch 4, the unlock operation of the lever lock 5, and the START operation of the grip switch 6—are performed, it is possible to reduce the energy consumption of the electric motor 3.

[0054] Furthermore, according to the above-described embodiment, the electric motor 3 stops when an off operation is received by the key switch 4, when a lock operation is received by the lever lock 5, or when a stop operation is received by the grip switch 6 while the electric motor 3 is running. Therefore, when work is paused, the electric motor 3 can be stopped quickly, thereby suppressing energy consumption by the electric motor 3.

[0055] Furthermore, according to the embodiment described above, when restarting the electric motor 3 that has stopped due to the locking operation of the lever lock 5, even if the lever lock 5 is unlocked, the controller 2 will not restart the electric motor 3 unless the grip switch 6 is started. Therefore, there is no possibility that the machine will perform an action unintended by the operator the moment the lever lock 5 is lowered, ensuring a high level of safety.

[0056] <2. Variant> The work machine according to the present invention is not limited to the embodiments described above, and various modifications and improvements are possible within the scope described in the claims.

[0057] For example, in the embodiments described above, an electric excavator 1 (see Figure 1) was used as an example of a work machine, but the invention is not limited to this. As shown in Figure 7, the concept of the present invention may also be applied to a hydraulic excavator 10, which is another example of a work machine.

[0058] Specifically, as shown in Figure 7, the hydraulic excavator 10 is equipped with an engine 8 as a power source. The operating lever 60 has a remote control valve that generates pilot pressure according to the amount of operation received by the operating lever 60 and outputs the pilot pressure to the control valve 37. When the operator pulls (lifts) the lever lock 5 and moves from the unlocked position to the locked position, the supply of pilot pressure to the remote control valve is cut off, and pilot pressure is no longer supplied to the control valve 37, rendering the lever operation by the operating levers 60L and 60R ineffective. On the other hand, when the operator lowers the lever lock 5 and moves from the locked position to the unlocked position, the supply of pilot pressure to the remote control valve is permitted, and pilot pressure is supplied to the control valve 37, making the lever operation by the operating levers 60L and 60R effective. Here, the starting control of the engine 8 is carried out according to the flowchart in Figure 5, similar to the starting control of the electric motor 3 in the embodiment described above. That is, after going through the processes of steps S11 to S13 in Figure 5 and proceeding to step S14, the controller 2 starts the engine 8, which is the power source. [Industrial applicability]

[0059] As described above, the work machine according to the present invention is suitable for controlling the starting and stopping of the drive source of a work machine, such as the motor of an electric excavator or the engine of a hydraulic excavator. [Explanation of Symbols]

[0060] 1 Electric Excavator 2 Controllers 3 Electric motor 4 Key Switches 5. Lever lock 6. Grip switch 8 engines 10 Hydraulic Excavator 31 batteries 33 Hydraulic pump 35 Solenoid valve 37 Control valve 60 (60L, 60R) Operating Lever

Claims

1. It is a work machine, Power source and Hydraulic actuators and A hydraulic pump driven by the aforementioned drive source and supplying pressurized oil to the hydraulic actuator, A control valve is positioned between the hydraulic actuator and the hydraulic pump, A pilot pump, driven by the aforementioned drive source and provided separately from the hydraulic pump, discharges the source pressure of the pilot pressure supplied to the control valve, A controller that controls the starting or stopping of the drive source, A first switch for receiving an ON operation to activate the controller and an OFF operation to stop the controller, An operating lever for operating the object being operated, A lever lock for receiving a lock operation to disable the lever operation by the aforementioned operating lever, and an unlock operation to enable the lever operation, A second switch for receiving a start operation to start the drive source and a stop operation to stop the drive source, Equipped with, The aforementioned drive source drives the hydraulic pump and the pilot pump, respectively. The aforementioned controller, The first switch is given the ON operation and the controller is activated. The lever lock is provided with the unlocking operation. and the starting operation is applied to the second switch. The system is configured to start the drive source only if all of the following conditions are met, and to not allow the drive source to start if any one of these conditions is not met. A work machine characterized in that it is configured so that the hydraulic pump and the pilot pump are not driven when the drive source is stopped.

2. The work machine according to claim 1, characterized in that the controller stops the drive source in any of the following cases while the drive source is being driven: when it determines that the first switch has received the off operation, when it determines that the lever lock has received the lock operation, or when it determines that the second switch has received the stop operation.

3. A work machine, Power source and A controller that controls the starting or stopping of the aforementioned drive source, A first switch for receiving an ON operation to activate the controller and an OFF operation to stop the controller, An operating lever for operating the object being operated, A lever lock for receiving a lock operation to disable the lever operation by the aforementioned operating lever, and an unlock operation to enable the lever operation, A second switch, provided separately from the first switch, is a switch for switching the start or stop of the drive source, and accepts a start operation to start the drive source and a stop operation to stop the drive source. Equipped with, The aforementioned controller, The first switch is given the ON operation and the controller is activated. The lever lock is provided with the unlocking operation. and the starting operation is applied to the second switch. The system is configured to start the drive source only if all of the following conditions are met, and to not allow the drive source to start if any one of these conditions is not met. During the operation of the aforementioned drive source, If the first switch determines that the off operation has been received, the drive source is stopped. If it is determined that the lock operation has been received by the lever lock, the drive source is also stopped. A work machine characterized in that it is configured to stop the drive source when it determines that the stop operation has been received by the second switch.

4. The work machine according to claim 2 or 3, characterized in that the controller, after determining that the lock operation has been received by the lever lock and stopping the drive source, will not start the drive source until it determines that the start operation has been received by the second switch, even if it determines that the unlock operation has been received by the lever lock, and further determines that the start operation has been received by the second switch.

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