Working machine

Abstract

To provide a working machine which can be prevented from operating in such a manner not intended by an operator when switching from an in-working machine operation mode to a remote operation mode.SOLUTION: A shovel comprises a vehicle body having a cab 5, a working device 10 connected to the vehicle body, an operating device 7 located within the cab 5, a movable remote operating device 28 for remote operation, and a control device 25 controlling witching between an on-board operation mode in which the vehicle body and the working device 10 are driven according to operation of the operating device 7, and a remote operation mode in which the vehicle body and working device 10 are driven according to operation of the remote operating device 28. When it is determined that an operator is not present within the cab 5 and that the remote operating device 28 is present outside the cab 5, the control device 25 allows switching from the on-board operation mode to the remote operation mode.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine such as a shovel. [Background technology]

[0002] Patent Document 1 discloses a shovel, which is one type of work machine. This shovel is equipped with a manual operating tool mounted on the shovel for manually operating the shovel, a transmitting unit portable by the operator for remotely operating the shovel, and a manual / remote changeover switch mounted on the shovel. The shovel is configured to switch between manual control (on-board operation mode) in which the shovel is driven in response to operation of the manual operating tool, and remote control (remote operation mode) in which the shovel is driven in response to operation of the transmitting unit, in response to operation of the manual / remote changeover switch. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-71281 Summary of the Invention [Problem to be solved by the invention]

[0004] The manual operating tool is generally arranged in the cab of the excavator. In an operation system in which an excavator is operated using a manual operating tool and a remote operation unit as in Patent Document 1, if the manual-remote changeover operation switch is operated by mistake, such as by contact, while the operator is in the cab to operate the excavator using the manual operating tool in the on-board operation mode, the excavator will switch from the on-board operation mode to the remote operation mode. If another person operates the transmission unit at this time, the excavator may be operated in a manner unintended by the operator in the cab. Furthermore, if the operator in the cab mistakenly believes that the remote operation unit is outside the cab when it is actually inside the cab and switches the excavator from the on-board operation mode to the remote operation mode using the manual-remote changeover operation switch, the excavator may be operated in a manner unintended by the operator in the cab due to mistaken operation, such as by contact with the operation unit.

[0005] An object of the present invention is to provide a work machine that can prevent the operator from performing an operation unintended by the operator when switching from the on-board operation mode to the remote operation mode. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a work machine including a vehicle body having a driver's cab, a working device connected to the vehicle body, an operating device arranged in the driver's cab, a movable remote operating device for remote operation, and a control device that controls switching between an on-board operation mode in which the vehicle body and the working device are driven in response to operation of the operating device, and a remote operation mode in which the vehicle body and the working device are driven in response to operation of the remote operating device, wherein the control device allows switching from the on-board operation mode to the remote operation mode when it is determined that an operator is not present in the driver's cab and that the remote operating device is present outside the driver's cab. [Effects of the Invention]

[0007] According to the present invention, when switching from the on-board operation mode to the remote operation mode, it is possible to prevent the operator from performing an operation that is not intended. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing the structure of a shovel in one embodiment of the present invention. [Figure 2] FIG. 1 is a diagram showing the configuration of a drive system of a shovel in one embodiment of the present invention. [Figure 3] 4 is a flowchart showing the processing content of a control device in one embodiment of the present invention. [Figure 4] 10 is a flowchart showing the processing contents of a control device in one modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will be described with reference to the drawings.

[0010] FIG. 1 is a side view showing the structure of a shovel in this embodiment.

[0011] The excavator comprises a running body 1 and a rotating body 2 rotatably provided above the running body 1, and the running body 1 and the rotating body 2 form a vehicle body. The running body 1 travels by the rotation of left and right running motors 3, and the rotating body 2 rotates by the rotation of a swing motor 4.

[0012] The rotating body 2 is equipped with a cab 5 in which an operator can sit. The cab 5 is provided with a driver's seat 6 in which the operator can sit, a plurality of operating devices 7 that can be operated by the operator, a locking device 8 that can be operated by the operator, a mode changeover switch 9 that can be operated by the operator (see FIG. 2 described later), and a human presence sensor 31 that detects the operator (see FIG. 2 described later).

[0013] A working device 10 is connected to the front side (left side in FIG. 1) of the rotating unit 2. The working device 10 includes a swing post 11 connected to the rotating unit 2 so as to be rotatable in the left-right direction, a boom 12 connected to the swing post 11 so as to be rotatable in the up-down direction, an arm 13 connected to the boom 12 so as to be rotatable in the up-down direction, and a bucket 14 connected to the arm 13 so as to be rotatable in the up-down direction. The swing post 11 rotates due to the extension and contraction of a swing cylinder (not shown), the boom 12 rotates due to the extension and contraction of a boom cylinder 15, the arm 13 rotates due to the extension and contraction of an arm cylinder 16, and the bucket 14 rotates due to the extension and contraction of a bucket cylinder 17.

[0014] The excavator is equipped with a drive system that drives a plurality of hydraulic actuators 18 (more specifically, the left and right traveling motors 3, the swing motor 4, the swing cylinder, the boom cylinder 15, the arm cylinder 16, and the bucket cylinder 17 described above). The details will be explained using FIG. 2. FIG. 2 is a diagram showing the configuration of the drive system in this embodiment. For convenience, FIG. 2 shows only the equipment mounted on the excavator that is involved in driving one hydraulic actuator 18 (more specifically, one control valve, a pair of proportional solenoid valves, one operating device, etc.).

[0015] The drive system of this embodiment includes a prime mover 19 (more specifically, an engine or an electric motor), a hydraulic pump 20 and a pilot pump 21 driven by the prime mover 19, multiple control valves 22 that control the flow (more specifically, the direction and flow rate) of pressure oil from the hydraulic pump 20 to multiple hydraulic actuators 18, multiple pairs of electromagnetic proportional valves 23A, 23B that generate pilot pressures that operate the multiple control valves 22 using the discharge pressure of the pilot pump 21 as the source pressure, a lock valve 24 provided between the pilot pump 21 and the multiple pairs of electromagnetic proportional valves 23A, 23B, and a control device 25 that controls the multiple pairs of electromagnetic proportional valves 23A, 23B. Although not shown, the control device 25 includes a processor that executes control according to a program and a memory that stores the program and data.

[0016] The locking device 8 has a lock lever 26 that can be switched between a locked position and an unlocked position, and a lock switch (not shown) that outputs a signal in response to the switching of the lock lever 26. The lock lever 26 is provided at the entrance to the operator's cab 5, and allows the operator to get on and off when switched to the locked position (raised position), and prevents the operator from getting on and off when switched to the unlocked position (lowered position). The lock switch outputs a signal to the lock valve 24 when the lock lever 26 is switched to the unlocked position.

[0017] The lock valve 24 is shut off when the lock lever 26 is switched to the locked position (i.e., when no signal is input from the lock switch). This disables all of the solenoid proportional valves 23A, 23B from generating pilot pressure, prohibiting the operation of all of the hydraulic actuators 18 (i.e., the operation of the traveling body 1, the revolving body 2, and the work implement 10). The lock valve 24 is connected when the lock lever 26 is switched to the unlocked position (i.e., when a signal is input from the lock switch). This enables all of the solenoid proportional valves 23A, 23B to generate pilot pressure, permitting the operation of all of the hydraulic actuators 18 (i.e., the operation of the traveling body 1, the revolving body 2, and the work implement 10).

[0018] The mode selector switch 9 (input device) receives an instruction to switch between the on-board operation mode and the remote operation mode, and the control device 25 controls the switching between the on-board operation mode and the remote operation mode. When the mode selector switch 9 receives an instruction to switch from the remote operation mode to the on-board operation mode, the control device 25 switches from the remote operation mode to the on-board operation mode. In the on-board operation mode, the control device 25 controls the solenoid proportional valves 23A, 23B in response to the operation of the operating device 7. This drives the hydraulic actuator 18, which in turn drives the traveling body 1, the revolving body 2, or the working device 10. The details of this will be explained below.

[0019] The operating device 7 has an operating member (more specifically, an operating lever or an operating pedal) that can be operated by an operator, a potentiometer (not shown) that detects the amount of operation on one side of the operating member and outputs a corresponding first operating signal, and a potentiometer (not shown) that detects the amount of operation on the other side of the operating member and outputs a corresponding second operating signal.

[0020] The control device 25 generates a drive signal corresponding to a first operation signal from the operating device 7 and outputs it to the solenoid proportional valve 23A. Then, the pilot pressure generated by the solenoid proportional valve 23A switches the control valve 22 to one switching position (the right side in FIG. 2), causing the hydraulic pump 20 to supply pressure oil to a port on one side (the left side in FIG. 2) of the hydraulic actuator 18, thereby driving the hydraulic actuator 18. Alternatively, the control device 25 generates a drive signal corresponding to a second operation signal from the operating device 7 and outputs it to the solenoid proportional valve 23B. Then, the pilot pressure generated by the solenoid proportional valve 23B switches the control valve 22 to the other switching position (the left side in FIG. 2), causing the hydraulic pump 20 to supply pressure oil to a port on the other side (the right side in FIG. 2) of the hydraulic actuator 18, thereby driving the hydraulic actuator 18.

[0021] The control device 25 switches from the on-board operation mode to the remote operation mode when the mode selector switch 9 receives an instruction to switch from the on-board operation mode to the remote operation mode while satisfying predetermined conditions (described in detail later). In the remote operation mode, the control device 25 controls the electromagnetic proportional valves 23A, 23B in response to the operation of the remote control device 28. This drives the hydraulic actuator 18, which in turn drives the traveling body 1, the revolving body 2, or the working device 10. The details of this will be described below.

[0022] The remote control device 28 is movable by an operator and is used for remote control. The remote control device 28 has a plurality of control levers 29 that can be operated by the operator, a potentiometer (not shown) that detects the amount of operation on one side of each control lever 29 and generates a corresponding first remote control signal, a potentiometer (not shown) on the other side that detects the amount of operation on the other side of each control lever 29 and generates a corresponding second remote control signal, and a wireless transmitter (not shown) that transmits the first or second remote control signal to the excavator.

[0023] The control device 25 receives a first or second remote control signal from the remote control device 28 via, for example, a wireless receiver 30 disposed in the operator's cab 5. The control device 25 generates a drive signal corresponding to the first remote control signal from the remote control device 28 and outputs it to the solenoid proportional valve 23A. The control valve 22 is then switched to one of the switching positions by the pilot pressure generated by the solenoid proportional valve 23A, causing the hydraulic pump 20 to supply pressure oil to one of the ports of the hydraulic actuator 18, thereby driving the hydraulic actuator 18. Alternatively, the control device 25 generates a drive signal corresponding to a second remote control signal from the remote control device 28 and outputs it to the solenoid proportional valve 23B. The control valve 22 is then switched to the other switching position by the pilot pressure generated by the solenoid proportional valve 23B, causing the hydraulic pump 20 to supply pressure oil to the other of the ports of the hydraulic actuator 18, thereby driving the hydraulic actuator 18.

[0024] Here, a feature of this embodiment is that the control device 25 allows switching from the on-board operation mode to the remote operation mode when it is determined that the operator is not in the cab 5 and that the remote control device 28 is outside a predetermined range (in this embodiment, the cab 5). The details of this will be explained using Fig. 3. Fig. 3 is a flowchart showing the processing contents of the control device in this embodiment.

[0025] In step S1, the control device 25 determines whether or not an operator is present in the cab 5, for example, based on the detection result of the human presence sensor 31 (see FIG. 2 above; for example, an infrared sensor, a camera, or a seat sensor). When it is determined that an operator is not present in the cab 5, the process proceeds to step S2.

[0026] In step S2, the control device 25 determines whether the remote control device 28 is outside a predetermined range (the driver's cab 5 in this embodiment) based on whether the strength of the signal transmitted from the remote control device 28 and received by the wireless receiver 30 is equal to or less than a threshold value (first threshold value). When it is determined that the remote control device 28 is outside the predetermined range because the strength of the signal transmitted from the remote control device 28 and received by the wireless receiver 30 is equal to or less than the threshold value, the process proceeds to step S3.

[0027] In step S3, the control device 25 allows switching from the on-board operation mode to the remote operation mode. That is, when the mode selector switch 9 receives an instruction to switch from the on-board operation mode to the remote operation mode, the control device 25 switches from the on-board operation mode to the remote operation mode.

[0028] When it is determined in step S1 that the operator is present in the cab 5, or when it is determined in step S2 that the strength of the signal transmitted from the remote control device 28 and received by the wireless receiver 30 exceeds a threshold and therefore the remote control device 28 is present within a predetermined range, the process proceeds to step S4.

[0029] In step S4, the control device 25 does not allow (prohibits) switching from the on-board operation mode to the remote operation mode. That is, even if the mode selector switch 9 receives an instruction to switch from the on-board operation mode to the remote operation mode, the control device 25 does not switch from the on-board operation mode to the remote operation mode.

[0030] As described above, the control device 25 of this embodiment allows switching from the on-board operation mode to the remote operation mode when the operator is not in the cab 5 and the remote control device 28 is outside the cab 5 (in other words, when the operator does not intend to operate the shovel manually but intends to operate it remotely). Therefore, unlike when switching from the on-board operation mode to the remote operation mode is allowed when the operator is in the cab 5 and the remote control device 28 is outside the cab (in other words, when the operator intends to operate the shovel manually but another person can remotely operate the shovel), it is possible to prevent the operator from performing an unintended action when switching from the on-board operation mode to the remote operation mode. This makes it possible to improve safety.

[0031] Furthermore, the control device 25 of this embodiment prohibits switching from the on-board operation mode to the remote operation mode when the operator is in the cab 5 or when the remote operation device 28 is in the cab 5. This further enhances safety.

[0032] In the above embodiment, the control device 25 switches from the on-board operation mode to the remote operation mode when the operator is not in the cab 5, the remote control device 28 is outside a predetermined range, and the mode selector switch 9 receives an instruction to switch from the on-board operation mode to the remote operation mode. However, the present invention is not limited to this. The control device 25 may automatically switch from the on-board operation mode to the remote operation mode when the operator is not in the cab 5 and the remote control device 28 is outside a predetermined range.

[0033] In the above embodiment, the control device 25 allows switching from the on-board operation mode to the remote operation mode when the conditions that the operator is not present in the cab 5 and the remote control device 28 is located outside a predetermined range are satisfied. However, other conditions may be added. For example, as in a modified example shown in FIG. 4 , in an additional step S5, the control device 25 may determine whether the lock lever 26 of the locking device 8 is switched to the unlocked position, for example, based on whether a signal is input from a lock switch. When it is determined that the lock lever 26 of the locking device 8 is switched to the locked position, the process proceeds to step S4, and the control device 25 does not allow switching from the on-board operation mode to the remote operation mode. In other words, even if the operator is not present in the cab 5 and the remote control device 28 is located outside the predetermined range, the control device 25 does not allow (prohibits) switching from the on-board operation mode to the remote operation mode when the lock lever 26 of the locking device 8 is in the locked position. On the other hand, when it is determined that the lock lever 26 of the locking device 8 is switched to the unlock position, the operator is not in the cab 5, and the remote control device 28 is outside the predetermined range, the process proceeds to step S3, and switching from the on-board operation mode to the remote operation mode is permitted. In this modified example, safety can be further improved by adding a condition for confirming the operator's intention to perform remote operation (switching the lock lever 26 of the locking device 8 to the unlock position).

[0034] Furthermore, in the above embodiment and modified example, the control device 25 has been described as determining whether the remote control device 28 is outside a predetermined range, specifically, outside the cab 5, but this is not limiting. The control device 25 may determine whether the remote control device 28 is outside the cab 5 and outside the working range of the work implement 10 (specifically, the range of a circle whose center is the center of rotation of the rotating unit 2 and whose radius is the maximum distance from the center of rotation of the rotating unit 2 to the bucket 14 of the work implement 10) based on, for example, whether the strength of a signal transmitted from the remote control device 28 and received by the wireless receiver 30 is equal to or less than a threshold (a second threshold, where the second threshold is less than the first threshold). In other words, even if the operator is not inside the cab 5 and the remote control device 28 is outside the cab 5, the control device 25 does not allow (prohibits) switching from the on-board operation mode to the remote operation mode when the remote control device 28 is within the working range of the work implement 10. This improves the safety of the operator carrying the remote control device 28.

[0035] Furthermore, in the above embodiment and modified examples, the mode changeover switch 9 is provided in the driver's cab 5, but this is not limiting. The mode changeover switch 9 may be provided in the remote control device 28, for example, or may be provided in both the driver's cab 5 and the remote control device 28. This allows for quick switching from the on-board operation mode to the remote operation mode.

[0036] Although the above description has been given taking as an example a case where the present invention is applied to a shovel, which is one type of work machine, the present invention is not limited to this and may be applied to other work machines. [Explanation of symbols]

[0037] 1. Running body 2 Rotating body 5. Driver's cab 7 Operating device 8 Locking device 9 Mode switch (input device) 10 Work equipment 25 Control device 28 Remote Control Device

Claims

1. a vehicle body having a driver's cab; a working device connected to the vehicle body; an operating device disposed in the driver's cab; a mobile remote control device for remote operation; a control device that controls switching between an on-board operation mode in which the vehicle body and the working device are driven in response to operation of the operation device and a remote operation mode in which the vehicle body and the working device are driven in response to operation of the remote operation device, the control device allows switching from the on-board operation mode to the remote operation mode when it is determined that an operator is not present in the cab and that the remote operation device is present outside the cab.

2. 2. The work machine according to claim 1, a control device that prohibits switching from the on-board operation mode to the remote operation mode when an operator is present in the cab or when the remote operation device is present in the cab.

3. 2. The work machine according to claim 1, a locking device that is provided in the driver's cab and that can be switched between a locked position that prohibits driving of the vehicle body and the working device and an unlocked position that allows driving of the vehicle body and the working device, the control device prohibits switching from the on-board operation mode to the remote operation mode when the locking device is in the locked position, even when an operator is not present in the cab and the remote operation device is present outside the cab.

4. 2. The work machine according to claim 1, the control device prohibits switching from the on-board operation mode to the remote operation mode when the remote operation device is within a working range of the work device, even when an operator is not present in the cab and the remote operation device is present outside the cab.

5. 2. The work machine according to claim 1, an input device that receives an instruction to switch from the on-board operation mode to the remote operation mode, the control device switches from the on-board operation mode to the remote operation mode when the input device receives an instruction to switch from the on-board operation mode to the remote operation mode while an operator is not present in the cab and the remote operation device is present outside the cab.

6. 2. The work machine according to claim 1, The control device automatically switches from the on-board operation mode to the remote operation mode when an operator is not present in the cab and the remote operation device is present outside the cab.

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