Work machine

Abstract

To suppress noise, and to prevent contact between a work machine and an object at the time of work start.SOLUTION: A work machine includes: a control device for suppressing an outside alarm by an alarm sound output device; an alarm mode switching device for switching between an effective mode for executing the outside alarm by the alarm sound output device when an object is detected by an object detection device and a disabled mode not executing it; and an operation mode switching device for switching between an operation possible state where a work device can operate and an operation impossible state where the work device cannot operate. In the case where the effective mode is set and when an operation preparation operation is performed for switching from the operation impossible state to the operation possible state by the operation mode switching device, the control device performs the outside alarm with a predetermined first notification mode, and in the case where the disabled mode is set and the operation preparation operation is performed, the control device performs the outside alarm with a second notification mode in which the degree of noise is lower than that in the first notification mode.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] There is known a work machine that issues an alarm to those around the vehicle when it detects an object around the vehicle (see Patent Document 1). While issuing an alarm to those around the vehicle can prevent contact between the work machine and objects in the vicinity, it may also cause noise disturbance to neighbors. Patent Document 1 discloses a work machine in which an external alarm function can be enabled or disabled in response to a predetermined operation by the operator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 218453 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 makes it possible to suppress the output of an alarm by disabling the external alarm function. However, if the external alarm function remains disabled when a work operation is started by a work machine, there is a risk that the work machine may come into contact with a worker or other person approaching the work machine before work begins (while it is stopped) when the work machine starts moving. In addition, no consideration is given to the noise that may be generated in the neighborhood when an alarm is output.

[0005] An object of the present invention is to provide a work machine that can prevent contact between the work machine and surrounding objects when starting work, while suppressing the generation of noise. [Means for solving the problem]

[0006] A work machine according to one aspect of the present invention comprises a vehicle body, a work device provided on the vehicle body, an object detection device that detects objects around the vehicle body, an alarm sound output device that issues an external alarm around the vehicle body by outputting a sound, a control device that controls the external alarm issued by the alarm sound output device based on the detection result of the object detection device, an alarm mode switching device that switches between an enabled mode in which the alarm sound output device issues an external alarm when the object is detected by the object detection device and a disabled mode in which the alarm sound output device does not issue an external alarm, and an operation mode switching device that switches between an enabled state in which the work device is operable and an disabled state in which the work device is inoperable. When the enabled mode is set by the alarm mode switching device and an operation preparation operation is performed by the operation mode switching device to switch from the disabled state to the operable state, the control device issues an external alarm by the alarm sound output device in a predetermined first alarm mode, and when the disabled mode is set by the alarm mode switching device and the operation preparation operation is performed, the control device issues an external alarm by the alarm sound output device in a second alarm mode that is quieter than the first alarm mode. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a work machine that can prevent contact between the work machine and surrounding objects when starting work, while suppressing the generation of noise. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a hydraulic excavator. [Figure 2] FIG. 2 is a diagram showing the object detection range of the object detection device provided in the hydraulic excavator. [Figure 3] FIG. 3 is a schematic view of the interior of the driver's cab as seen from the rear of the driver's seat toward the front. [Figure 4] FIG. 4 is a diagram showing a control system that controls each part of the hydraulic excavator according to the first embodiment. [Figure 5]FIG. 5 is a functional block diagram relating to external alarm control by the vehicle body controller according to the first embodiment. [Figure 6] FIG. 6 is a main flowchart of the warning control executed by the vehicle body controller according to the first embodiment. [Figure 7] FIG. 7 is a flowchart showing the operation start warning control of FIG. [Figure 8] FIG. 8 is a flowchart showing the details of the human detection alarm control of FIG. [Figure 9] FIG. 9 is a flowchart showing the details of the operation start warning control executed by the vehicle body controller according to the second embodiment. [Figure 10] FIG. 10 is a diagram showing a control system that controls each part of the hydraulic excavator according to the third embodiment. [Figure 11] FIG. 11 is a table showing examples of the first notification mode and the second notification mode. DETAILED DESCRIPTION OF THE INVENTION

[0009] A working machine according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an example will be described in which the working machine is a crawler hydraulic excavator.

[0010] First Embodiment Fig. 1 is a side view of a hydraulic excavator 1. For ease of explanation, the front-rear and up-down directions of the hydraulic excavator 1 are defined as shown in Fig. 1. That is, in this embodiment, unless otherwise specified, the front of the driver's seat (left direction in the figure) is defined as the front of the hydraulic excavator 1.

[0011] The hydraulic excavator 1 comprises a vehicle body (machine body) 4 and a working device 10 attached to the vehicle body 4. The vehicle body 4 comprises a running body 2 and a rotating body 3 that is rotatably mounted on the running body 2. The working device 10 is attached to the front of the rotating body 3. The running body 2 travels by driving a pair of left and right crawlers by a traveling motor 2a. The rotating body 3 is driven by a swing motor 3a and rotates relative to the running body 2.

[0012] The revolving body 3 has a revolving frame 8, an operator's cab 7 provided on the front left side of the revolving frame 8, a counterweight 9 provided at the rear of the revolving frame 8, and an engine room 6 provided on the revolving frame 8 behind the operator's cab 7. The engine room 6 is equipped with hydraulic equipment such as an engine 80 serving as a prime mover and hydraulic pumps (main pump 31 and pilot pump 32 shown in FIG. 4) driven by the engine 80. A working device 10 is rotatably connected to the center of the front of the revolving frame 8.

[0013] The working device 10 is an articulated working device having a plurality of rotatably connected driven members and a plurality of hydraulic cylinders that drive the plurality of driven members. In this embodiment, three driven members, namely a boom 11, an arm 12, and a bucket 13, are connected in series. The base end of the boom 11 is rotatably connected to the front of the revolving frame 8 by a boom pin 11b. The base end of the arm 12 is rotatably connected to the tip of the boom 11 by an arm pin 12b. The bucket 13 is rotatably connected to the tip of the arm 12 by a bucket pin 13b.

[0014] The boom 11 is driven by a hydraulic cylinder (hereinafter also referred to as boom cylinder 11a) which is a hydraulic actuator, and rotates relative to the revolving frame 8. The arm 12 is driven by a hydraulic cylinder (hereinafter also referred to as arm cylinder 12a) which is a hydraulic actuator, and rotates relative to the boom 11. The bucket 13 is driven by a hydraulic cylinder (hereinafter also referred to as bucket cylinder 13a) which is a hydraulic actuator, and rotates relative to the arm 12.

[0015] A speaker (horn speaker) 23 is provided on the top of the rotating body 3. The speaker 23 is an alarm sound output device that issues an external alarm to workers and other people around the vehicle body 4 by outputting sound. Lights 22 are provided on the outer periphery of the rotating body 3. The lights 22 are provided on the left side, right side, and rear of the rotating body 3. The lights 22 are light-emitting devices that emit light to issue an external alarm to workers and other people around the vehicle body 4. The lights 22 are equipped with a plurality of light-emitting diodes (LEDs).

[0016] Fig. 2 is a diagram showing an object detection range 72 of an object detection device 71 provided in the hydraulic excavator 1. Fig. 2 shows the object detection range 72 when the hydraulic excavator 1 is viewed from above. The hydraulic excavator 1 according to this embodiment is equipped with a plurality of object detection devices 71 attached to the revolving body 3 and detecting objects around the revolving body 3, and a vehicle controller 100 which is a control device that controls external alarms using the speaker 23 and the light 22 based on the detection results of the object detection devices 71.

[0017] The multiple object detection devices 71 are arranged taking into consideration the working range of the hydraulic excavator 1 and the blind spots of the operator. The working range of the hydraulic excavator 1 is the range that the tip of the working implement 10 can reach when the working implement 10 and the rotating unit 3 are operated while the traveling unit 2 is stopped. The working range is set, for example, based on the maximum turning radius of the hydraulic excavator 1. The maximum turning radius corresponds to the length from the central axis of rotation of the rotating unit 3 to the tip of the bucket 13 when the working implement 10 is extended forward (in a direction perpendicular to the central axis of rotation). The multiple object detection devices 71 (71L, 71R, 71B) are arranged at predetermined positions on the rotating unit 3 so that the majority of the working range is covered by their object detection ranges 72 (72L, 72R, 72B).

[0018] Object detection device 71B detects objects within a fan-shaped object detection range 72B set on the rear side of the revolving unit 3. Object detection device 71L detects objects within a fan-shaped object detection range 72L set on the left side of the revolving unit 3. Object detection device 71R detects objects within a fan-shaped object detection range 72R set on the right side of the revolving unit 3.

[0019] The object detection device 71 includes a detection unit and a detection controller connected to the detection unit and the vehicle body controller 100. The detection unit is a unit that integrates a 3D sensor as an object detection sensor for detecting objects (obstacles) and an imaging device that captures images of the surroundings of the vehicle body 4. The detection controller determines whether or not an object is present within a predetermined object detection range 72 based on information output from the 3D sensor of the detection unit, and outputs the determination result to the vehicle body controller 100.

[0020] The 3D sensor is, for example, an infrared sensor that uses the optical pulse time-of-flight (TOF) method. The object detection range 72 of the 3D sensor is a range in which objects can be detected in both the vertical and horizontal directions. The bottom end of each object detection range 72 is set above a certain height so that the traveling body 2 of the hydraulic excavator 1 itself is not detected as an obstacle. The object detection range 72 of each object detection device 71 is set by a detection controller.

[0021] The detection controller of the object detection device 71 determines whether one or more objects (people, vehicles, etc.) are present within the object detection range 72 based on the signal from the detection unit, and outputs the determination result to the vehicle body controller 100. When an object is detected by the object detection device 71, it means that the detection controller of the object detection device 71 has determined that an object is present. When an object is not detected by the object detection device 71, it means that the detection controller of the object detection device 71 has determined that an object is not present. Note that the 3D sensor is not limited to an infrared sensor, and various sensors can be used. For example, the 3D sensor may be an ultrasonic sensor, a millimeter-wave radar, a LiDAR (Light Detection and Ranging), or the like.

[0022] Furthermore, the detection controller of the object detection device 71 outputs data of the image captured by the imaging device to the vehicle body controller 100. The imaging device is, for example, a wide-angle video camera equipped with an imaging element such as a CCD or CMOS, which has excellent durability and weather resistance, and a wide-angle lens.

[0023] 3 is a schematic diagram of the interior of the cab 7 as viewed from the rear of the cab 75 toward the front. As shown in FIG. 3, the interior of the cab 7 is provided with the cab 75 in which the operator sitting in the cab 7 is seated, indoor operation lever devices B1 to B4 for operating each part of the hydraulic excavator 1, and a vehicle controller 100 for controlling the operation of the hydraulic excavator 1.

[0024] A touch panel monitor 18 is attached to the support pillar 76 on the right side as viewed from the driver's seat 75. The touch panel monitor 18 has a display device that displays various types of information to the operator, and an input device for making various settings for the hydraulic excavator 1. The display device of the touch panel monitor 18 is, for example, a liquid crystal display, and displays on a display screen a display image that shows various types of information, such as operating information for the hydraulic excavator 1, based on control signals from the vehicle body controller 100. The input device of the touch panel monitor 18 is, for example, a touch sensor that can be operated by a finger, a touch pen, or the like, and inputs predetermined information to the vehicle body controller 100 in response to operation by the operator.

[0025] An indoor control lever device B1 for operating the bucket 13 and the boom 11 is provided to the right of the driver's seat 75, and an indoor control lever device B2 for operating the revolving unit 3 and the arm 12 is provided to the left of the driver's seat 75. A pair of indoor control lever devices B3 and B4 are provided in front of the driver's seat 75. The indoor control lever device B4 is an operation lever for operating the left crawler, and the indoor control lever device B3 is an operation lever for operating the right crawler. Hereinafter, the indoor control lever devices B1 to B4 will be collectively referred to as the operation device 34. The indoor control lever devices B1 and B2 constitute the operation device 34 for operating the work device 10. The indoor control lever device B2 constitutes the operation device 34 for operating the revolving unit 3. The indoor control lever devices B3 and B4 constitute the operation device 34 for operating the traveling unit 2.

[0026] A gate lock lever device 60 is provided inside the cab 7 on the left side (door side) of the left indoor operation lever device B2. The gate lock lever device 60 can be switched between an inactive position (hereinafter also referred to as a locked position) that allows entry and exit of the cab 7 and disables operation of the operation device 34, and an active position (hereinafter also referred to as an unlocked position) that prohibits entry and exit of the cab 7 and enables operation of the operation device 34. When the gate lock lever device 60 is operated to the inactive position, the working device 10 is placed in an inoperable state in which it is inoperable. When the gate lock lever device 60 is operated to the active position, the working device 10 is placed in an operable state in which it is operable. In other words, the gate lock lever device 60 functions as an operation mode switching device that switches between an operable state and an inoperable state.

[0027] A mode selector switch 19, which is an alarm mode switching device for switching the control mode of the external alarm, is provided inside the operator's cab 7. By operating the mode selector switch 19, the operator can switch the control mode of the external alarm between an enabled mode and an disabled mode.

[0028] The mode selector switch 19 can be manually switched between an enabled position and an disabled position. The enabled position is an operating position for setting the external alarm control mode to the enabled mode. In the enabled mode, if the object detection device 71 detects an operator or the like around the hydraulic excavator 1 (object detection range 72) while the hydraulic excavator 1 is working, an external alarm is issued by the speaker 23. The disabled position is an operating position for setting the external alarm control mode to the disabled mode. In the disabled mode, even if an operator or the like is present around the hydraulic excavator 1 (object detection range 72) while the hydraulic excavator 1 is working, an external alarm is not issued by the speaker 23. Note that in the disabled mode, a configuration may be adopted in which an external alarm is not issued even if the object detection device 71 detects an operator or the like, or a configuration may be adopted in which object detection by the object detection device 71 is not performed at all.

[0029] When the operator switches the mode selector switch 19 from the disabled position to the enabled position, a valid operation signal is output from the mode selector switch 19 to the vehicle body controller 100. When the operator switches the mode selector switch 19 from the enabled position to the disabled position, a valid operation signal is output from the mode selector switch 19 to the vehicle body controller 100.

[0030] FIG. 4 is a diagram showing a control system that controls each part of the hydraulic excavator 1. Note that, hereinafter, the travel motor (hydraulic motor) 2a, swing motor (hydraulic motor) 3a, boom cylinder (hydraulic cylinder) 11a, arm cylinder (hydraulic cylinder) 12a, and bucket cylinder (hydraulic cylinder) 13a mounted on the hydraulic excavator 1 are collectively referred to as hydraulic actuators. The hydraulic excavator 1 is provided with a plurality of hydraulic actuators, but FIG. 4 illustrates only a hydraulic cylinder 37 (e.g., boom cylinder 11a) for driving a driven member of the work implement 10 as a representative. Furthermore, an electric operating device 34 that operates the hydraulic actuators, solenoid proportional valves 33a, 33b that are driven in response to operation of the operating device 34, and a flow control valve 40 are provided for each of the plurality of hydraulic actuators, but FIG. 4 illustrates only the configuration for controlling one hydraulic actuator as a representative.

[0031] As shown in FIG. 4, the hydraulic system 30 of the hydraulic excavator 1 includes a main pump 31, a pilot pump 32, a hydraulic cylinder 37 driven by hydraulic oil supplied from the main pump 31, a flow control valve (control valve) 40 that controls the flow (flow rate and direction) of hydraulic oil supplied from the main pump 31 to the hydraulic cylinder 37, and electromagnetic proportional valves 33 (33a, 33b) that output a command pilot pressure (pilot pressure) that drives the flow control valve 40.

[0032] The main pump 31 and the pilot pump 32 are connected to an engine 80 and driven by the engine 80 to discharge hydraulic oil (pressurized oil). The main pump 31 is a variable displacement hydraulic pump, and the pilot pump 32 is a fixed displacement hydraulic pump. The engine 80 is a drive source that drives the hydraulic pumps (i.e., a power source for the hydraulic excavator 1), and is configured by an internal combustion engine such as a diesel engine, for example.

[0033] The electromagnetic proportional valves 33a, 33b are pressure reducing valves that generate command pilot pressure using the pressure (discharge pressure) of the hydraulic oil discharged from the pilot pump 32, which is a pilot hydraulic source, as their source pressure and output the command pilot pressure to pressure receiving sections 41a, 41b of the flow control valve 40. The electromagnetic proportional valves 33a, 33b are controlled based on a control signal (control current) from the vehicle body controller 100. The operation device 34 provided inside the operator's cab 7 commands the operations of the work implement 10, the revolving unit 3, and the traveling unit 2 in response to operation by the operator. The operation device 34 has an operation lever 34a that can be tilted, and an operation sensor 34b that outputs a signal (wired operation signal) to the vehicle body controller 100 in accordance with the operation amount (operation angle) of the operation lever 34a.

[0034] The vehicle body controller 100 controls the electromagnetic proportional valves 33a, 33b based on wired operation signals from the operation device 34. The operation device 34 corresponds to the indoor operation lever devices B1 to B4 (see FIG. 3) corresponding to the hydraulic actuator. For example, if the hydraulic cylinder 37 shown in FIG. 4 is the boom cylinder 11a, the operation device 34 is the indoor operation lever device B1 on the right side of the driver's seat.

[0035] When the command pilot pressure generated by the solenoid proportional valve 33a acts on the pressure-receiving portion 41a of the flow control valve 40, which is located in the neutral position (N), the flow control valve 40 is driven in one direction, and the flow control valve 40 is switched from the neutral position (N) to the first position (P1). As a result, pressure oil discharged from the main pump 31 is guided to the bottom chamber of the hydraulic cylinder 37 (boom cylinder 11a), and hydraulic oil is discharged from the rod chamber to the tank 39, causing the hydraulic cylinder 37 (boom cylinder 11a) to extend. As a result, the driven member (boom 11) rotates in the first direction (upward).

[0036] When the command pilot pressure generated by the solenoid proportional valve 33b acts on the pressure-receiving portion 41b of the flow control valve 40, which is located in the neutral position (N), the flow control valve 40 is driven in the other direction, and the flow control valve 40 is switched from the neutral position (N) to the second position (P2). As a result, pressure oil discharged from the main pump 31 is guided to the rod chamber of the hydraulic cylinder 37 (boom cylinder 11a), and hydraulic oil is discharged from the bottom chamber to the tank 39, causing the hydraulic cylinder 37 (boom cylinder 11a) to contract. As a result, the driven member (boom 11) rotates in the second direction (downward).

[0037] The hydraulic oil discharged from the main pump 31 is supplied to the hydraulic cylinder 37 through a flow control valve 40 to drive the working device 10. Although not shown, the hydraulic oil discharged from the main pump 31 is also supplied to the swing motor 3a and the traveling motor 2a through flow control valves to drive the swing unit 3 and the traveling unit 2, respectively.

[0038] The gate lock lever device 60 has a gate lock lever 60a and an operation position sensor 60b that detects the operation position of the gate lock lever 60a and outputs an operation signal representing the detection result to the vehicle body controller 100. A lock valve 36 is provided in a pilot line 38, which is an oil passage connecting the pilot pump 32 and the electromagnetic proportional valve 33. The lock valve 36 is an electromagnetic switching valve that is switched between an open position that opens the pilot line 38 and a closed position that closes the pilot line 38, depending on the operation position of the gate lock lever 60a.

[0039] When the operator switches the gate lock lever 60a from the lock position to the unlock position, that is, when an unlock operation that validates the operation of the operating device 34 is performed, an unlock operation signal is output from the operation position sensor 60b to the vehicle body controller 100. When the operator switches the gate lock lever 60a from the unlock position to the lock position, that is, when a lock operation that invalidates the operation of the operating device 34 is performed, a lock operation signal is output from the operation position sensor 60b to the vehicle body controller 100.

[0040] When an unlock operation signal is input from the operation position sensor 60b to the vehicle body controller 100, the vehicle body controller 100 supplies power to the lock valve 36. This switches the lock valve 36 to the open position. When the gate lock lever 60a is in the unlock position, a command pilot pressure corresponding to the operation amount of the operation lever 34a is generated by the solenoid proportional valve 33, and the hydraulic actuator corresponding to the operated operation lever 34a is operated. In other words, when the gate lock lever 60a is operated to the unlock position (a position that closes the entrance / exit), the operation of the hydraulic actuator by the operation device 34 becomes possible (a state in which operation of the operation device 34 is valid).

[0041] When a lock operation signal is input from the operation position sensor 60b to the vehicle body controller 100, the vehicle body controller 100 stops the supply of power to the lock valve 36. This switches the lock valve 36 to the shut-off position. The pilot source pressure to the solenoid proportional valve 33 is shut off, and operation by the operation lever 34a is disabled. In other words, when the gate lock lever 60a is operated to the lock position (a position that opens the entrance / exit), operation of the hydraulic actuator by the operation device 34 becomes disabled (operation of the operation device 34 becomes disabled).

[0042] The hydraulic excavator 1 is equipped with a vehicle body controller 100, which is a control device that controls various devices such as a touch panel monitor 18, lights 22, speakers 23, and an electromagnetic proportional valve 33. The vehicle body controller 100 is composed of a computer that includes a processing device 101 such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), or DSP (Digital Signal Processor), a non-volatile memory 102 such as a ROM (Read Only Memory), flash memory, or hard disk drive, a volatile memory 103 known as RAM (Random Access Memory), an input interface, an output interface, and other peripheral circuits. These pieces of hardware work together to run software and realize multiple functions. The vehicle body controller 100 may be composed of a single computer or multiple computers.

[0043] The nonvolatile memory 102 stores programs capable of executing various calculations. In other words, the nonvolatile memory 102 is a storage medium (storage device) from which programs for realizing the functions of this embodiment can be read. The volatile memory 103 is a storage medium (storage device) that temporarily stores the results of calculations performed by the processing device 101 and signals input from the input interface. The processing device 101 is a device that loads the programs stored in the nonvolatile memory 102 into the volatile memory 103 and executes the calculations, and performs predetermined calculations on data taken in from the input interface, the nonvolatile memory 102, and the volatile memory 103 in accordance with the programs.

[0044] The input interface converts signals input from various devices into data that can be calculated by the processing device 101. The output interface generates an output signal according to the calculation result in the processing device 101, and outputs the signal to various devices.

[0045] The hydraulic excavator 1 is equipped with an engine controller 130, which is a control device that controls the rotational speed of the engine 80. The engine controller 130 is connected to the vehicle body controller 100. The engine controller 130 controls the rotational speed of the engine 80 by adjusting the amount of fuel injected into the cylinders of the engine 80 using a fuel injector 80b. The engine 80 is provided with a rotational speed sensor 80a that detects the rotational speed of the engine 80. The engine controller 130 controls the fuel injector 80b so that the actual rotational speed detected by the rotational speed sensor 80a becomes the target rotational speed of the engine 80 output from the vehicle body controller 100.

[0046] The functions of the vehicle body controller 100 will be described in detail with reference to Fig. 5. Fig. 5 is a functional block diagram related to external alarm control by the vehicle body controller 100. As shown in Fig. 5, the vehicle body controller 100 has functions as a detection determination unit 111, a mode setting unit 112, an operation determination unit 113, and an alarm control unit 114.

[0047] The detection determination unit 111 determines whether or not an object detection state is in place based on a signal output from the object detection device 71. The detection determination unit 111 determines that an object detection state is in place when a signal indicating that an object has been detected in at least one of the object detection ranges 72 of the multiple object detection devices 71 is input. The detection determination unit 111 determines that an object detection state is not in place (i.e., an object non-detection state) when a signal indicating that an object has not been detected in any of the object detection ranges 72 of the multiple object detection devices 71 is input.

[0048] The detection determination unit 111 determines whether or not the detected object is a person based on the detection result of the object detection device 71. In other words, the detection determination unit 111 determines whether or not a person has been detected as an object based on the signal output by the object detection device 71. Various methods can be used to determine whether or not the detected object is a person (person detection method). For example, the detection determination unit 111 determines whether or not the detected object is a person based on an image captured by the image capture device of the object detection device 71. The detection determination unit 111 can recognize people in the captured image by arbitrarily applying a known image processing method, a machine learning-based classifier, or the like.

[0049] A well-known image processing method is, for example, template matching (pattern matching). The detection and determination unit 111 performs a matching process using a template that is predetermined for the shape of a body part such as a person's head. When the body part is extracted from the captured image through the matching process, the detection and determination unit 111 determines that the object including the body part is a person.

[0050] The detection determination unit 111 may determine that the detected object is a person when the intensity of the reflected wave received by the 3D sensor of the object detection device 71 is within a predetermined range. Alternatively, the detection determination unit 111 may determine whether or not the object is a person by so-called sensor fusion, based on both the captured image captured by the imaging device and the detection result of the 3D sensor. Furthermore, the method of detecting a person is not limited to the case where the detection determination unit 111 determines whether or not the detected object is a person by a matching process or the like. The detection controller of the object detection device 71 may perform a matching process or the like to determine whether or not the object is a person, and the detection determination unit 111 may determine whether or not the person is detected based on a signal representing the determination result from the object detection device 71. That is, the detection determination unit 111 may determine that a person has been detected when the signal acquired from the object detection device 71 indicates that a person has been detected, and may determine that a person has not been detected when the signal acquired from the object detection device 71 indicates that a person has not been detected.

[0051] The mode setting unit 112 sets the control mode of the external alarm by the speaker 23 and the light 22 to either an effective mode or an ineffective mode based on an operation signal from the mode selector switch 19. When an effective operation signal is input from the mode selector switch 19, the mode setting unit 112 sets the control mode of the external alarm to the effective mode. When an ineffective operation signal is input from the mode selector switch 19, the mode setting unit 112 sets the control mode of the external alarm to the ineffective mode.

[0052] The operation determination unit 113 determines whether or not an operation preparation operation for making the working implement 10, the traveling unit 2, and the revolving unit 3 operable, i.e., an unlock operation, has been performed, based on an operation signal from the operation position sensor 60b of the gate lock lever device 60. When the operation position sensor 60b detects that the gate lock lever 60a has been operated from the lock position to the unlock position, the operation determination unit 113 determines that an unlock operation has been performed.

[0053] The operation determination unit 113 determines whether or not a lock operation (hydraulic lock operation) has been performed to render the working implement 10, the traveling unit 2, and the revolving unit 3 inoperable, based on an operation signal from the operation position sensor 60b of the gate lock lever device 60. When the operation position sensor 60b detects that the gate lock lever 60a has been operated from the unlocked position to the locked position, the operation determination unit 113 determines that a lock operation has been performed.

[0054] The alarm control unit 114 controls the speaker 23, the light 22, and the touch panel monitor 18 based on the determination results of the detection determination unit 111, the mode setting unit 112, and the operation determination unit 113. The speaker 23 outputs an alarm sound based on a control command from the alarm control unit 114. The alarm sound is, for example, a sound or voice guidance of a predetermined pattern. The light 22 outputs an alarm light based on a control command from the alarm control unit 114. The alarm light is, for example, output in a predetermined light emission pattern. The touch panel monitor 18 displays a warning screen on the display screen based on a control command from the alarm control unit 114. The warning screen includes an image such as a message or icon indicating that an object has been detected around the hydraulic excavator 1.

[0055] The details of the warning control executed by the vehicle body controller 100 will be described with reference to the flowcharts of Figures 6 to 8. Figure 6 is a main flowchart of the warning control executed by the vehicle body controller 100. Figure 7 is a flowchart showing the details of the operation start warning control of Figure 6, and Figure 8 is a flowchart showing the details of the human detection warning control of Figure 6.

[0056] The process of the flowchart shown in FIG. 6 is started, for example, when the ignition switch is turned on (that is, the key is turned on), and is repeatedly executed after initial settings including the start-up process of the object detection device 71 are performed.

[0057] In step S110, the vehicle body controller 100 executes operation start warning control to notify workers and the like around the hydraulic excavator 1 that work by the hydraulic excavator 1 will begin. When the operation start warning control is completed, the process proceeds to the next step S140.

[0058] In step S140, if a person (worker, etc.) enters the object detection range 72 during work by the hydraulic excavator 1, the vehicle body controller 100 executes human detection alarm control to warn the person. When the human detection alarm control is completed, the processing shown in the flowchart of Fig. 6 ends. As a result, the operation start alarm control of step S110 is executed again.

[0059] The operation start warning control (step S110 in FIG. 6) will be described in detail with reference to FIG. 7. In step S113, the operation determination unit 113 determines whether or not an unlocking operation (operation preparation operation) has been performed. If an unlocking operation has been performed, the operation determination unit 113 determines that an operation preparation operation has been performed, and proceeds to step S116. This determination process (step S113) is repeatedly executed until a positive determination is made.

[0060] In step S116, the alarm control unit 114 determines whether the control mode of the external alarm is set to the valid mode or the invalid mode. If it is determined that the valid mode is set, the process proceeds to step S121. If it is determined that the valid mode is not set (i.e., the invalid mode is set), the process proceeds to step S124.

[0061] In step S121, the alarm control unit 114 issues an external alarm in a predetermined first alarm mode. The alarm control unit 114 controls the speaker 23 to continuously output a beep sound from the speaker 23 for a predetermined period of time, and also to output from the speaker 23 an audio guide including a message notifying the user that work has started. The alarm control unit 114 also controls the light 22 to turn on a red LED included in the light 22 for a predetermined period of time. In other words, the first alarm mode is an alarm mode in which an audio guide is output together with a beep sound (continuous sound), and a red light is turned on.

[0062] In step S124, the alarm control unit 114 issues an external alarm in a predetermined second alarm mode. The alarm control unit 114 controls the speaker 23 to output audio guidance from the speaker 23. The alarm control unit 114 also controls the light 22 to turn on the red LED included in the light 22 for a predetermined period of time. In other words, the second alarm mode is an alarm mode in which audio guidance is output and a red light is turned on. In the external alarm in the second alarm mode, no beep sound is output.

[0063] In this embodiment, the notification mode of the external alarm using the light 22 is the same in the first and second notification modes. Meanwhile, the notification mode of the external alarm using the speaker 23 is different in the first and second notification modes. As described above, the first notification mode includes a beep, whereas the second notification mode does not. A beep is a sound composed of a single waveform. The frequency of the beep output in the external alarm in the first notification mode is approximately 2000 Hz. The frequency of the voice guidance output in the external alarm in the first and second notification modes is approximately 500 to 1000 Hz, which is lower than the frequency of the beep. Thus, the second notification mode is a notification mode that omits the beep sound of the first notification mode. This results in a lower noise level of the external alarm in the second notification mode than in the first notification mode. Specifically, in the second notification mode, the beep sound is omitted, resulting in a lower sound pressure level [dB] and a lower maximum sound frequency [Hz] than in the first notification mode. The lower the sound pressure level, the lower the noise level.

[0064] When the warning (steps S121, S124) notifying the start of work by the hydraulic excavator 1 ends, the operation start warning control (step S110 in FIG. 6) is completed.

[0065] The details of the human detection alarm control (step S140 in FIG. 6) will be described with reference to FIG. 8. In step S143, the operation determination unit 113 determines whether or not a locking operation has been performed. If it is determined that a locking operation has not been performed (i.e., if the operation position of the gate lock lever 60a is maintained in the unlocked position), the process proceeds to step S146. If it is determined that a locking operation has been performed, the process proceeds to step S155.

[0066] In step S146, the detection determination unit 111 determines whether or not an object has been detected by the object detection device 71. If the detection determination unit 111 determines that an object has not been detected by the object detection device 71, the process proceeds to step S155. If the detection determination unit 111 determines that an object has been detected by the object detection device 71, the detection determination unit 111 determines whether or not the detected object is a person, that is, whether or not a person has been detected as an object. If the detection determination unit 111 determines that the detected object is a person, that is, if it determines that a person has been detected, the process proceeds to step S149. If the detection determination unit 111 determines that the detected object is not a person, that is, if it determines that a person has not been detected, the process proceeds to step S155.

[0067] In step S149, the alarm control unit 114 determines whether the control mode of the external alarm is set to the valid mode or the invalid mode. If it is determined that the valid mode is set, the process proceeds to step S152. If it is determined that the valid mode is not set (i.e., the invalid mode is set), the process proceeds to step S155.

[0068] In step S152, the alarm control unit 114 issues an external alarm in a predetermined alarm mode. The alarm control unit 114 controls the speaker 23 to output a beep sound intermittently for a predetermined period of time from the speaker 23, and also to output from the speaker 23 an audio guide including a message to warn a person (such as a worker) who has entered the object detection range 72. The alarm control unit 114 also controls the light 22 to flash a red LED included in the light 22 for a predetermined period of time. In other words, the alarm mode when a person is detected is an alarm mode in which audio guidance is output together with a beep sound (intermittent sound), and a red light is flashed, which differs from the first and second alarm modes.

[0069] In step S155, the alarm control unit 114 stops the external alarm if an external alarm is being issued. This completes the human detection alarm control (step S140 in FIG. 6). Note that if an external alarm is not being issued, the control to stop the external alarm is omitted, and the human detection alarm control (step S140 in FIG. 6) is completed.

[0070] The order of the alarm control processes is not limited to the above example. For example, the order of the processes in step S146 and step S149 in Fig. 8 may be reversed.

[0071] According to the above-described embodiment, the following advantageous effects are achieved.

[0072] (1) A hydraulic excavator (work machine) 1 includes a vehicle body 4, a working implement 10 provided on the vehicle body 4, an object detection device 71 that detects objects around the vehicle body 4, a speaker (alarm sound output device) 23 that issues an external alarm around the vehicle body 4 by outputting sound, a vehicle body controller (control device) 100 that controls the external alarm issued by the speaker 23 based on the detection result of the object detection device 71, a mode selector switch (alarm mode selector) 19 for switching the control mode of the external alarm between an enabled mode and a disabled mode, and a gate lock lever device (operation mode selector) 60 that switches between an enabled state in which the working implement 10 is operable and an disabled state in which the working implement 10 is inoperable. The enabled mode is a control mode in which an external alarm is issued by the speaker 23 when an object is detected by the object detection device 71. The disabled mode is a control mode in which an external alarm is not issued by the speaker 23 when an object is detected by the object detection device 71. The vehicle body controller 100 sets the control mode for the external alarm by the speaker 23 to either an enabled mode or an disabled mode based on an operation signal from the mode selector switch 19. Based on an operation signal from the gate lock lever device 60, the vehicle body controller 100 determines whether an unlocking operation (operation preparation operation) has been performed to make the working device 10 operable.

[0073] When the valid mode is set by the mode selector switch 19, the vehicle body controller 100 issues an external alarm through the speaker 23 when an object is detected by the object detection device 71 (Yes in S146, Yes in S149, S152 in FIG. 8). When the invalid mode is set by the mode selector switch 19, the vehicle body controller 100 does not issue an external alarm through the speaker 23 when an object is detected by the object detection device 71 (Yes in S146, No in S149, S155 in FIG. 8). In other words, when the invalid mode is set, the vehicle body controller 100 does not issue an external alarm through the speaker 23 even if a person (object) is present within the object detection range 72 of the object detection device 71.

[0074] When the valid mode is set by the mode selector switch 19 and an unlocking operation (operation preparation operation) for switching from an inoperable state to an operable state is performed by the gate lock lever device 60, the vehicle body controller 100 issues an external alarm through the speaker 23 in a predetermined first alarm mode (Yes in S113, Yes in S116, S121 in FIG. 7). When the invalid mode is set by the mode selector switch 19 and an unlocking operation is performed, the vehicle body controller 100 issues an external alarm through the speaker 23 in a second alarm mode that is quieter than the first alarm mode (Yes in S113, No in S116, S124 in FIG. 7).

[0075] In this configuration, when the valid mode is set, an alarm sound is output when a person (worker, etc.) enters the object detection range 72 of the object detection device 71. This makes it possible to prevent contact between the hydraulic excavator 1 and the intruding person (worker, etc.). Furthermore, when the invalid mode is set, no alarm sound is output even if a person (worker, etc.) enters the object detection range 72 of the object detection device 71, making it possible to suppress the generation of noise.

[0076] In this configuration, regardless of the external alarm control mode, an alarm sound is output when an unlocking operation is performed and each part of the hydraulic excavator 1 (the working implement 10, the traveling unit 2, and the rotating unit 3) is in an operable state (i.e., the hydraulic excavator 1 is in a workable state). This makes it possible to prevent contact between the hydraulic excavator 1 and people in the vicinity (workers, etc.) when work starts. Note that the alarm sound notification mode when the disabled mode is set (second alarm mode) is different from the alarm sound notification mode when the enabled mode is set (first alarm mode), so that workers and operators can recognize whether the control mode is set to the enabled mode or the disabled mode. In an external alarm in the first alarm mode, the vehicle controller 100 causes the speaker 23 to output an alarm sound that is unpleasant to people in order to attract their attention. This makes it possible to effectively prevent contact between the hydraulic excavator 1 and people in the vicinity (workers, etc.) when work starts. In contrast, the noise level of the external alarm in the second notification mode is smaller than the noise level of the external alarm in the first notification mode. That is, in the external alarm in the second notification mode, the vehicle body controller 100 causes the speaker 23 to output an alarm sound that is difficult to recognize as noise. This makes it possible to prevent contact between the hydraulic excavator 1 and people (workers, etc.) in the vicinity when work starts, while suppressing the generation of noise.

[0077] (2) The first notification mode is a notification mode in which at least a beep sound is output. In this embodiment, voice guidance is output along with the beep sound. The second notification mode outputs voice guidance without outputting a beep sound, thereby reducing the sound pressure level. In other words, the second notification mode is a notification mode in which the level of noise is reduced compared to the first notification mode by reducing the types of sounds output. The frequency of the beep sound is higher than the frequency of the voice guidance. For this reason, the beep sound is more likely to be perceived as noise than a human voice. In other words, the beep sound is more likely to be perceived as noise. In an external alarm in the second notification mode, noise can be reduced by not outputting a beep sound.

[0078] (3) The hydraulic excavator 1 includes an operating device 34 that operates the work implement 10, the traveling unit 2, and the revolving unit 3, and a gate lock lever device (lock operating device) 60 that serves as an operation mode switching device that switches between an inoperable state and an operable state and that is capable of performing a lock operation that disables operation of the operating device 34 and an unlock operation that enables operation of the operating device 34. When an unlock operation is performed by the gate lock lever device 60 (when the operating position is switched from the lock position to the unlock position), the vehicle body controller 100 determines that an operation preparation operation has been performed by the operating device 34 to make each part of the hydraulic excavator 1 operable. In other words, the operation preparation operation according to this embodiment is an unlock operation of the gate lock lever device 60. With this configuration, an external alarm can be issued when an unlock operation is performed by the gate lock lever device 60.

[0079] (4) The vehicle body controller 100 determines whether or not a person has been detected as an object based on the signal output by the object detection device 71 (S146 in FIG. 8). When the valid mode is set and the vehicle body controller 100 determines that a person has been detected based on the signal from the object detection device 71, the vehicle body controller 100 issues an external alarm through the speaker 23 (Yes in S146, Yes in S149, S152 in FIG. 8). When the valid mode is set and the vehicle body controller 100 determines that a person has not been detected based on the signal from the object detection device 71, the vehicle body controller 100 does not issue an external alarm through the speaker 23 (No in S146, S155 in FIG. 8). With this configuration, an external alarm can be issued only when a person is present within the object detection range 72.

[0080] Second Embodiment A hydraulic excavator 1 according to a second embodiment of the present invention will be described with reference to Fig. 9. Note that the same reference symbols are used to designate components that are the same as or equivalent to those described in the first embodiment, and differences will be mainly described.

[0081] Fig. 9 is a flowchart similar to Fig. 7, showing the details of the operation start warning control executed by the vehicle body controller 100 according to the second embodiment. In the flowchart of Fig. 9, the processes of steps S215 and S227 are added to the flowchart of Fig. 7.

[0082] If it is determined in step S113 that an unlock operation (operation preparation operation) has been performed, the process proceeds to step S215. In step S215, the detection determination unit 111 determines whether or not an object has been detected by the object detection device 71. If the detection determination unit 111 determines that an object has not been detected by the object detection device 71, the process proceeds to step S227. If the detection determination unit 111 determines that an object has been detected by the object detection device 71, the detection determination unit 111 determines whether or not the detected object is a person. If the detection determination unit 111 determines that the detected object is a person, the process proceeds to step S116. If the detection determination unit 111 determines that the detected object is not a person, the process proceeds to step S227.

[0083] In step S227, the alarm control unit 114 issues an external alarm in the third alarm mode. The alarm control unit 114 controls the speaker 23 to continuously output a beep sound from the speaker 23 for a predetermined period of time, and also to output from the speaker 23 an audio guide including a message notifying the user that work has started. The alarm control unit 114 also controls the light 22 to turn on the red LED included in the light 22 for a predetermined period of time. In other words, the third alarm mode is an alarm mode in which audio guidance is output along with a beep sound (continuous sound), and a red light is turned on. The third alarm mode differs from the first alarm mode in that the volume (volume, sound pressure level) of the beep sound in the third alarm mode is smaller than the volume (volume, sound pressure level) of the beep sound in the first alarm mode.

[0084] As described above, the vehicle body controller 100 according to the second embodiment issues an external alarm through the speaker 23 in the first alarm mode if an object is detected by the object detection device 71 and the valid mode is set when an operation preparation operation is performed. Furthermore, the vehicle body controller 100 according to the second embodiment issues an external alarm through the speaker 23 in the second alarm mode if an object is detected by the object detection device 71 and the invalid mode is set when an operation preparation operation is performed. Furthermore, the vehicle body controller 100 according to the second embodiment issues an external alarm through the speaker 23 in the third alarm mode, which is quieter than the first alarm mode, when an object is not detected by the object detection device 71 when an operation preparation operation is performed.

[0085] In this configuration, by setting the third notification mode to an output mode of the alarm sound that is less likely to be recognized as noise (for example, a mode in which the volume is reduced), it is possible to suppress the generation of noise more than in the first embodiment.

[0086] <Modification of the second embodiment> 9, an external alarm is issued in the third notification mode, but the external alarm may not be issued. In other words, if an object is not detected by the object detection device 71 when an operation preparation operation is performed, the vehicle body controller 100 does not issue an external alarm through the speaker 23. According to this configuration, similar to the second embodiment, noise generation can be suppressed more than in the first embodiment.

[0087] <Third embodiment> A hydraulic excavator 1 according to a third embodiment of the present invention will be described with reference to FIG. 10. Components that are the same as or equivalent to those described in the first embodiment will be assigned the same reference symbols, and differences will be mainly described. In the first embodiment, an example was described in which an external alarm is issued in the first or second notification mode when an operator in the cab 7 performs an unlocking operation using the gate lock lever device 60. In contrast, in the third embodiment, an example will be described in which, when the hydraulic excavator 1 is remotely operated, an external alarm is issued in the first or second notification mode when an operator performs an unlocking operation using the remote control device 5.

[0088] Fig. 10 is a diagram similar to Fig. 4, showing a control system for controlling each part of the hydraulic excavator 1 according to the third embodiment. As shown in Fig. 10, the hydraulic excavator 1 according to the third embodiment includes a wireless receiver 20 that receives a wireless operation signal transmitted from the remote control device 5.

[0089] The remote control device 5 is a wireless control device that can be carried by the operator and that can remotely control the hydraulic excavator 1. The remote control device 5 includes a plurality of remote control lever devices A1 to A4, a plurality of remote control switches 53, a wireless communication device 52 for wirelessly communicating with the hydraulic excavator 1, and a terminal controller 54. The plurality of remote control switches 53 include an ignition switch 53a for remotely starting the engine 80 of the hydraulic excavator 1, a lock switch (operation mode switching device, lock operating device) 53b for applying or releasing the hydraulic lock, and a mode switching switch (alarm mode switching device) 53c for switching between an enabled mode and an disabled mode. The plurality of remote control lever devices A1 to A4 have the same functions as the plurality of indoor operation lever devices B1 to B4 (see FIG. 3) that constitute the operation device 34 provided inside the operator's cab 7 of the hydraulic excavator 1.

[0090] The terminal controller 54 functions as a terminal control device that controls the wireless communication device 52. The terminal controller 54 is composed of a microcomputer that includes a processing device such as a CPU, a volatile memory called RAM (Random Access Memory) as a storage device, a non-volatile memory such as a flash memory, an input / output interface (not shown), and other peripheral circuits.

[0091] The terminal controller 54 transmits wireless operation signals (remote operation signals) to the hydraulic excavator 1 via the wireless communication device 52 in response to the operations of the remote control lever devices A1 to A4, the ignition switch 53a, the lock switch 53b, the mode changeover switch 53c, etc.

[0092] When an engine start operation (for example, a long press operation for a predetermined time or more) is performed using the ignition switch 53a of the remote control device 5, an engine start signal is transmitted to the hydraulic excavator 1. When the vehicle body controller 100 receives the engine start signal via the wireless receiver 20, it executes start control of the engine 80. When an engine stop operation (for example, a short press operation for less than a predetermined time) is performed using the ignition switch 53a of the remote control device 5, an engine stop signal is transmitted to the hydraulic excavator 1. When the vehicle body controller 100 receives the engine stop signal via the wireless receiver 20, it executes stop control of the engine 80.

[0093] When an unlock operation (for example, a long press operation for a predetermined time or longer) is performed using the lock switch 53b of the remote control device 5, an unlock signal is transmitted to the hydraulic excavator 1. When the unlock signal is received via the wireless receiver 20, the vehicle body controller 100 switches the lock valve 36 to the open position. When a lock operation (for example, a short press operation for less than a predetermined time) is performed using the lock switch 53b of the remote control device 5, a lock signal is transmitted to the hydraulic excavator 1. When the lock signal is received via the wireless receiver 20, the vehicle body controller 100 switches the lock valve 36 to the shut-off position.

[0094] When an operation to switch the external alarm control mode from the disabled mode to the enabled mode is performed using the mode selector switch 53c of the remote control device 5 (for example, a long press operation for a predetermined time or longer), a valid operation signal is transmitted to the hydraulic excavator 1. When the vehicle body controller 100 receives the valid operation signal via the wireless receiver 20, it sets the external alarm control mode to the enabled mode. When an operation to switch the external alarm control mode from the enabled mode to the disabled mode is performed using the mode selector switch 53c of the remote control device 5 (for example, a short press operation for less than a predetermined time), a valid operation signal is transmitted to the hydraulic excavator 1. When the vehicle body controller 100 receives the invalid operation signal via the wireless receiver 20, it sets the external alarm control mode to the disabled mode.

[0095] According to the third embodiment, in the operation determination process (S113) of FIG. 7, if an unlock signal is input, the vehicle body controller 100 proceeds to step S116. As described above, the third embodiment differs from the first embodiment in that the unlock operation, the switching operation of the external alarm control mode, and the like are performed by the remote control device 5. Other controls are performed in the same manner as in the first embodiment. Therefore, the third embodiment achieves the same effects as the first embodiment.

[0096] <Modification of the third embodiment> In the third embodiment, an example has been described in which the remote control device 5 is a portable device that can be carried around. However, the remote control device 5 may be a fixed device that imitates the operation device 34 in the driver's cab 7.

[0097] The following modified examples are also within the scope of the present invention, and it is possible to combine the configuration shown in the modified example with the configuration described in the above embodiment, to combine the configurations described in the different embodiments above, or to combine the configurations described in the different modified examples below.

[0098] <Variation 1> In the first embodiment, the first alert mode is an alert mode in which a beep and voice guidance are output, and the second alert mode is an alert mode in which voice guidance is output without outputting a beep. However, examples of the first alert mode and the second alert mode are not limited to the examples described in the above embodiment. The second alert mode only needs to have a lower noise level than the first alert mode. The noise level corresponds to the degree to which a person who hears a sound feels uncomfortable. The noise level is correlated with the loudness (sound pressure level) of the sound, the output time of the sound, and the frequency of the sound. Specifically, the louder the sound (sound pressure level), the longer the output time of the sound, and the higher the frequency, the higher the noise level. In other words, the second alert mode may be any of an alert mode in which the loudness (sound pressure level) of the sound is lower than the first alert mode, an alert mode in which the output time of the sound is shorter than the first alert mode, and an alert mode in which the frequency of the sound is lower than the first alert mode. Fig. 11 is a table showing examples of the first notification mode and the second notification mode. Fig. 11 shows only the notification mode using the speaker 23, and omits the notification mode using the light 22. Modified examples of the first notification mode and the second notification mode will be described with reference to Fig. 11.

[0099] <Variation 1-1> Only the volume (volume, sound pressure level) of the alarm sound may differ between the first and second alert modes. In Modification 1-1, the volume (volume, sound pressure level) of the sound output by the external alarm in the second alert mode is smaller than the volume (volume, sound pressure level) of the sound output by the external alarm in the first alert mode. In this manner, in Modification 1-1, the volume of the sound output from the speaker 23 is smaller in the second alert mode than in the first alert mode. According to this modification, by setting the control mode of the external alarm to the disabled mode, the volume (volume, sound pressure level) of the alarm sound can be reduced when work begins. In other words, by reducing the volume of the alarm sound, the degree of noise of the alarm sound can be reduced. This makes it possible to suppress the generation of noise.

[0100] <Variation 1-2> Only the output time of the alarm sound may differ between the first and second alert modes. In Modification 1-2, the output time of the alarm sound in the second alert mode (e.g., about 1 second) is shorter than the output time of the alarm sound in the first alert mode (e.g., about 5 seconds). Thus, in Modification 1-2, the duration of the sound output from speaker 23 is shorter in the second alert mode than in the first alert mode. According to this modification, by setting the control mode of the external alarm to the disabled mode, the output time of the alarm sound when work starts can be shortened. In other words, by shortening the output time of the alarm sound, the noise level of the alarm sound can be reduced. This makes it possible to suppress the generation of noise.

[0101] <Variation 1-3> Only the frequency of the alarm sound may differ between the first and second alert modes. In Modification 1-3, the frequency of the alarm sound in the second alert mode (e.g., about 1000 Hz) is lower than the frequency of the alarm sound in the first alert mode (e.g., about 2000 Hz). Thus, in Modification 1-3, the frequency of the sound output from speaker 23 is lower in the second alert mode than in the first alert mode. According to this modification, by setting the external alarm control mode to the disabled mode, the frequency of the alarm sound when work begins can be lowered. In other words, by lowering the frequency of the alarm sound, the noise level of the alarm sound can be reduced. This makes it possible to suppress the generation of noise.

[0102] <Variation 1-4> Only the output pattern of the alarm sound may differ between the first and second alert modes. In Modification 1-4, the output pattern of the alarm sound in the first alert mode is a continuous sound in which sound is output continuously for a predetermined time, and the output pattern of the alarm sound in the second alert mode is an intermittent sound in which sound is output intermittently for a predetermined time. Thus, in Modification 1-4, the total output time of sound output from speaker 23 is shorter in the second alert mode than in the first alert mode. According to this modification, by setting the control mode of the external alarm to the disabled mode, the total output time of the alarm sound when work starts can be reduced. In other words, the noise level of the alarm sound can be reduced by reducing the total output time of the alarm sound. This makes it possible to suppress noise generation.

[0103] <Variation 1-5> In Modification 1-5, the output pattern of the alarm sound in the first and second alert modes is an intermittent sound, in which sound is output intermittently for a predetermined time. However, the interval between sounds in the intermittent sound, i.e., the time from the stop of sound output to the start of the next sound output, differs between the first and second alert modes. The output duration of one intermittent sound is the same in the first and second alert modes. Thus, in Modification 1-5, the interval between sounds of the alarm sound (intermittent sound) in the second alert mode is longer than the interval between sounds of the alarm sound (intermittent sound) in the first alert mode. Therefore, in Modification 1-5, similar to Modification 1-4, the total output duration of the sound output from the speaker 23 is shorter in the second alert mode than in the first alert mode. According to this modification, by setting the external alarm control mode to the disabled mode, the total output duration of the alarm sound at the start of work can be reduced. In other words, the noise level of the alarm sound can be reduced by reducing the total output duration of the alarm sound. This makes it possible to suppress the generation of noise.

[0104] <Variation 2> In the second embodiment, the third alert mode described above is an example in which the volume (volume, sound pressure level) of the beep sound is smaller than that of the first alert mode. However, the present invention is not limited to this. As in Variation 1-2 above, the output time of the alarm sound in the third alert mode may be shorter than that of the first alert mode. As in Variation 1-3 above, the frequency of the alarm sound in the third alert mode may be lower than that of the first alert mode. As in Variation 1-4 and Variation 1-5 above, the output patterns of the alarm sounds in the first and third alert modes may be set so that the total output time of the sound output from the speaker 23 is shorter in the third alert mode than in the first alert mode. In other words, it is sufficient that the noise level of the external alarm in the third alert mode is smaller than that of the external alarm in the first alert mode.

[0105] <Variation 3> In the first embodiment, an example has been described in which it is determined that an operation preparation operation has been performed when an unlocking operation is performed by the gate lock lever device (operation mode switching device, lock operation device) 60. In the second embodiment, an example has been described in which it is determined that an operation preparation operation has been performed when an unlocking operation is performed by the lock switch (operation mode switching device, lock operation device) 53b of the remote control device 5. However, the present invention is not limited to these.

[0106] For example, in the first embodiment, the vehicle body controller 100 may determine that an operation preparation operation has been performed when an operation to start the engine 80 is performed using the ignition switch. Furthermore, in the second embodiment, the vehicle body controller 100 may determine that an operation preparation operation has been performed when an operation to start the engine 80 is performed using the remote control device 5. Specifically, when the ignition switch 53a of the remote control device 5 is operated, an engine start signal is transmitted from the remote control device 5 to the hydraulic excavator 1. When the engine start signal is input to the vehicle body controller 100 via the wireless receiver 20, the vehicle body controller 100 determines that an operation preparation operation has been performed. Note that when the engine start signal is input, the vehicle body controller 100 preferably issues an external alarm in the first or second notification mode and then starts start control of the engine 80.

[0107] As described above, the hydraulic excavator (work machine) 1 according to this modification includes a main pump (hydraulic pump) 31 that supplies hydraulic oil to the actuators (boom cylinder 11a, arm cylinder 12a, and bucket cylinder 13a) of the work implement 10, and an engine (drive source) 80 that drives the main pump 31. The vehicle controller (control device) 100 determines that an operation preparation operation has been performed when an operation to start the engine 80 has been performed. In other words, the operation preparation operation according to this modification is an operation to start the engine 80. In this case, the ignition switch 53a can be said to be an operation mode switching device that switches between an inoperable state and an operable state. With this configuration, an external alarm can be issued when an operation to start the engine 80 is performed.

[0108] <Variation 4> In the above embodiment, an example has been described in which, when the valid mode is set and an object is detected by the object detection device 71, an external alarm is issued by the light 22, and when the invalid mode is set, an external alarm is not issued by the light 22 even if an object is present within the object detection range 72 of the object detection device 71. However, even when the invalid mode is set, an external alarm may be issued by the light 22.

[0109] The hydraulic excavator (work machine) 1 according to this modification is equipped with a light (light-emitting device) 22 that emits light to issue an external alarm around the vehicle body 4. When an object is detected by the object detection device 71, the vehicle body controller (control device) 100 issues an external alarm using the light 22 regardless of the external alarm control mode. That is, when the valid mode is set, the vehicle body controller 100 according to this modification issues an external alarm using the speaker 23 and the light 22 when an object is detected by the object detection device 71. Furthermore, when the invalid mode is set, the vehicle body controller 100 according to this modification issues an external alarm using the light 22 but does not issue an external alarm using the speaker 23 when an object is detected by the object detection device 71. According to this configuration, when the invalid mode is set and an object (person) is detected, an alarm sound is not output, but an alarm light is output. This makes it possible to effectively prevent contact between the hydraulic excavator 1 and workers during operation while suppressing noise generation.

[0110] <Variation 5> In the above embodiment, an example has been described in which an external alarm is issued in a predetermined alarm mode when a person is detected. However, an external alarm may also be issued in a predetermined alarm mode when an object other than a person, such as a work vehicle such as a dump truck or a wheel loader, is detected. With this configuration, it is possible to notify the operator of the work vehicle that the work vehicle has entered the object detection range 72 of the object detection device 71 of the hydraulic excavator 1.

[0111] <Variation 6> In the above embodiment, the engine 80 is used as the drive source for driving the main pump 31. However, the drive source for driving the main pump 31 may be an electric motor.

[0112] <Variation 7> In the above embodiment, an example has been described in which the object detection device 71 includes a 3D sensor and an imaging device. However, the object detection device 71 may be configured to include either a 3D sensor or an imaging device.

[0113] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments. [Explanation of symbols]

[0114] 1...hydraulic excavator (work machine), 2...traveling body, 2a...traveling motor (hydraulic motor, hydraulic actuator), 3...swivel body, 3a...swivel motor (hydraulic motor, hydraulic actuator), 4...vehicle body (machine body), 5...remote control device, 7...operator's room (cab), 10...working device, 11...boom, 11a...boom cylinder (hydraulic cylinder, hydraulic actuator), 12...arm, 12a...arm cylinder (hydraulic cylinder, hydraulic actuator), 13...bucket, 13a...bucket cylinder (hydraulic cylinder, hydraulic actuator), 18...touch panel monitor (display device, input device), 19...mode change switch (alarm mode change device), 22...light (light-emitting device), 23...speaker (alarm sound output device), 31...main pump (hydraulic pump), 34...operating device, 34a...operating lever, 34b ...operation sensor, 36...lock valve, 37...hydraulic cylinder (hydraulic actuator), 53a...ignition switch (operation mode switching device), 53b...lock switch (operation mode switching device, lock operation device), 53c...mode switching switch (alarm mode switching device), 54...terminal controller, 60...gate lock lever device (operation mode switching device, lock operation device), 60a...gate lock lever, 60b...operation position sensor, 71...object detection device, 72...object detection range, 80...engine (drive source), 100...vehicle body controller (control device), 101...processing device, 102...non-volatile memory, 103...volatile memory, 111...detection determination unit, 112...mode setting unit, 113...operation determination unit, 114...alarm control unit, A1 to 4...remote operation lever device, B1 to B4...indoor operation lever device

Claims

1. A work machine comprising a vehicle body, a work device provided on the vehicle body, an object detection device that detects objects around the vehicle body, an alarm sound output device that issues an external alarm around the vehicle body by outputting sound, and a control device that controls the external alarm issued by the alarm sound output device based on the detection result of the object detection device, an alarm mode switching device for switching between an effective mode in which an external alarm is issued by the alarm sound output device when the object is detected by the object detection device and an ineffective mode in which no external alarm is issued; an operation mode switching device for switching between an operable state in which the working device is operable and an inoperable state in which the working device is inoperable; Equipped with The control device when the valid mode is set by the alarm mode switching device and an operation preparation operation for switching from the inoperable state to the operable state is performed by the operation mode switching device, an external alarm is issued by the alarm sound output device in a predetermined first alert mode, When the invalid mode is set by the alarm mode switching device and the operation preparation operation is performed, the alarm sound output device issues an external alarm in a second alarm mode that is lower in noise than the first alarm mode. A work machine characterized by:

2. 2. The work machine according to claim 1, The volume of the sound output from the alarm sound output device is smaller in the second alert mode than in the first alert mode. A work machine characterized by:

3. 2. The work machine according to claim 1, The duration of the sound output from the alarm sound output device is shorter in the second alert mode than in the first alert mode. A work machine characterized by:

4. 2. The work machine according to claim 1, the first notification mode is a notification mode in which at least a beep sound is output, The second notification mode is a notification mode in which the beep sound is not output but a voice guidance is output. A work machine characterized by:

5. 2. The work machine according to claim 1, an operating device for operating the working device; the operation mode switching device is a lock operation device capable of a lock operation that disables operation of the operation device and an unlock operation that enables operation of the operation device, The operation preparation operation is the unlocking operation of the lock operation device. A work machine characterized by:

6. 2. The work machine according to claim 1, a hydraulic pump that supplies hydraulic oil to an actuator of the working device; a drive source that drives the hydraulic pump, the operation preparation operation is an operation for starting the driving source, A work machine characterized by:

7. 2. The work machine according to claim 1, The control device When the operation preparation operation is performed, if the object is detected by the object detection device and the valid mode is set, an external alarm is issued by the alarm sound output device in the first alarm mode, When the operation preparation operation is performed, if the object is detected by the object detection device and the disable mode is set, an external alarm is issued by the alarm sound output device in the second alarm mode, When the object is not detected by the object detection device when the operation preparation operation is performed, an external alarm is issued by the alarm sound output device in a third alarm mode that is lower in noise level than the first alarm mode, or an external alarm is not issued by the alarm sound output device. A work machine characterized by:

8. 2. The work machine according to claim 1, The control device determining whether a person has been detected as the object based on the signal output by the object detection device; When the valid mode is set and it is determined that a person has been detected, an external alarm is issued by the alarm sound output device, When the valid mode is set and it is determined that no person is detected, the alarm sound output device does not issue an external alarm. A work machine characterized by:

9. 2. The work machine according to claim 1, a light-emitting device that emits light to give an external warning around the vehicle body; When the valid mode is set and the object is detected by the object detection device, an external alarm is issued by the alarm sound output device and the light-emitting device; When the invalid mode is set and the object is detected by the object detection device, an external alarm is issued by the light-emitting device, but an external alarm is not issued by the alarm sound output device. A work machine characterized by:

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