Safety devices for industrial machinery

Abstract

To consistently perform a safety control of a work machine.SOLUTION: A safety system comprises: a detection part 60A that is a detection part capable of detecting objects around a hydraulic shovel 1, having a detection range centering a center axis CL that extends in the direction away from the detection part in a plan view; and a controller 70 that makes judgement, based on a detection result of the aforesaid detection part, of an object entering a monitoring area set relatively to the upper revolving body 12 and executes the safety control according to the judgement result. The detection part 60A is mounted on the upper revolving body 12 in such a way that the center axis CL extends parallel to the center line CA of the work device 14 in the opposite side of the cab 18 in relation to the center line CA in a plan view. The aforesaid monitoring area includes a first monitoring area A1 comprising a first outer edge A1 that extends along the center axis CL in the aforesaid detection part side of the work device 14 in a plan view.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a safety device for a working machine.

Background Art

[0002] Conventionally, in a working machine such as a hydraulic excavator, a device that detects a detection target present around the working machine and performs safety control is known. The working machine includes a lower traveling body, an upper revolving body rotatably supported by the lower traveling body, and an attachment rotatably supported in the vertical direction by the upper revolving body.

[0003] Patent Document 1 discloses a device that restricts the operating speed of the upper revolving body when an object enters a monitoring area set around the upper revolving body of a working machine. In this technology, the distance from the upper revolving body to surrounding objects is detected by a detector such as an ultrasonic sensor or an infrared laser attached to the upper revolving body, and the entry of the object is detected based on the detection result. Further, Patent Document 1 discloses that sensors such as lasers and millimeter-wave radars, cameras, etc. can also be used as the detector.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Detectors such as cameras and ultrasonic sensors have partial variations in detection accuracy within their detection range. Therefore, the technology described in Patent Document 1 has the problem that it is difficult to accurately detect the entry of an object into the monitoring area due to the detection errors of such detectors. In particular, the tip portion of an attachment in a work machine rotates at a high peripheral speed at a position far from the rotation center of the upper rotating body. Therefore, a safety device with high precision is required to reliably prevent contact between the tip portion and the object.

[0006] The present invention aims to provide a safety device for a work machine that can accurately detect objects located around the work machine. [Means for solving the problem]

[0007] The present invention provides a safety device for a work machine. The safety device comprises a detection unit capable of detecting objects in the vicinity of the work machine, the detection unit having a detection range centered on a central axis that extends away from the detection unit in a plan view, and a control unit that determines whether the object has entered a monitoring area set relative to the upper body of the work machine based on the detection result of the detection unit, and performs safety control according to the determination result. The detection unit is mounted on the upper body such that, in a plan view, the central axis extends along the center line with respect to the center line of the work member of the work machine, on the opposite side of the cab of the work machine. The monitoring area includes a first monitoring area having a first outer edge that extends along the central axis on the side of the detection unit that is closer to the work member than the work member in a plan view.

[0008] In this configuration, the detection unit is mounted on the back side of the work member as viewed from the cab of the upper body, and the first monitoring area is set so that the first outer edge of the first monitoring area extends along the central axis of the detection unit. As a result, the detection unit can detect objects with particularly high accuracy around the first outer edge, and interference between the work member and the object in areas that are difficult for the operator inside the cab to see can be suppressed by safety control.

[0009] In the above configuration, the first monitoring area may be set such that the first outer edge and the central axis are parallel in a plan view.

[0010] With this configuration, since the first outer edge of the first monitoring area and the central axis of the detection unit are set parallel to each other, the detection unit can detect the object with particularly high accuracy around the first outer edge, regardless of the distance from the upper body of the object.

[0011] In the above configuration, the first monitoring area may be set such that the first outer edge and the central axis overlap in a plan view.

[0012] With this configuration, the detection unit can detect the object with even higher accuracy around the first outer edge, regardless of the distance from the upper body of the object.

[0013] In the above configuration, the working member may include a base end supported by the upper body and a tip end opposite to the base end, and in a plan view, the first outer edge may extend away from the center line as it moves forward from the upper body, and the first monitoring area may be set such that it intersects the central axis in the area adjacent to the tip end of the working member.

[0014] With this configuration, the first outer edge and the central axis intersect around the tip of the working member, which improves the accuracy of object detection in this area and particularly suppresses interference between the tip, where the peripheral speed is highest due to the rotational movement of the upper body, and the object.

[0015] In the above configuration, the control unit may, based on the detection result of the detection unit, determine that the object has entered the first monitoring area and then stop a predetermined operation of the work machine as a safety control.

[0016] With this configuration, the operation of the work machine is stopped when the object enters the first monitoring area from the first outer edge, thus preventing interference between the object and the work machine with high precision.

[0017] In the above configuration, the monitoring area may further include a second monitoring area that is located on the opposite side of the work member when viewed from the first monitoring area in a plan view, and is in contact with the first monitoring area with the first outer edge as the boundary.

[0018] With this configuration, by placing the second monitoring area outside the first monitoring area, interference between the object and the work machine can be prevented in stages.

[0019] In the above configuration, the control unit may, based on the detection result of the detection unit, determine that the object has entered the first monitoring area and stop a predetermined operation of the work machine as a safety control, and if it determines that the object has entered the second monitoring area, it may slow down a predetermined operation of the work machine as a safety control.

[0020] With this configuration, as the object enters the second monitoring area, the operation of the work machine is slowed down, allowing for more reliable stop control in the subsequent first monitoring area.

[0021] In the above configuration, the device further comprises a sub-detection unit capable of detecting objects around the work machine, the sub-detection unit having a sub-detection range centered on a sub-central axis that extends away from the sub-detection unit in a plan view, the sub-detection unit being mounted on the upper body on the same side as the cab with respect to the center line in a plan view, with the sub-central axis extending along the center line, and the monitoring area further including a sub-monitoring area that extends along the sub-central axis on the side of the sub-detection unit that is closer to the work member in a plan view.

[0022] According to this configuration, by mounting the sub-detection unit on the same side of the working member as the cab in the upper main body, safety control for the object can be executed on both the left and right sides of the working member. As a result, the safety of the working machine can be further enhanced.

[0023] In the above configuration, in the left-right direction of the upper main body, the width of the sub-monitoring area may be set to be smaller than the width of the first monitoring area.

[0024] According to this configuration, by relatively setting the width of the sub-monitoring area to be small, it is possible to prevent excessive activation of safety control in an area that is easily visible to the operator in the cab while executing safety control for the object on both the left and right sides of the working member.

[0025] In the above configuration, it may further include a monitoring area switching unit that can switch between a state where the first monitoring area includes an area overlapping the working member in a plan view and a state where the first monitoring area does not include an area overlapping the working member in a plan view.

[0026] According to this configuration, depending on the situation at the work site, it is possible to switch the range of the first monitoring area between a case where it is desired to activate safety control in the area below the working member and a case where activation of safety control in the same area is prohibited.

Advantages of the Invention

[0027] As described above, according to the present invention, there is provided a safety device for a working machine capable of accurately detecting an object located around the working machine.

Brief Description of the Drawings

[0028] [Figure 1] It is a side view showing a hydraulic excavator which is an example of a working machine according to a first embodiment of the present invention. [Figure 2] It is a plan view of the hydraulic excavator. [Figure 3] It is a block diagram showing a hydraulic circuit, a controller, etc. mounted on the hydraulic excavator. [Figure 4] Block diagram showing the main functions of the aforementioned controller. [Figure 5] This graph shows the result of a camera, which is an example of a detection unit according to one embodiment of the present invention, detecting an object. [Figure 6] This is a plan view of a hydraulic excavator, which is an example of a work machine according to the second embodiment of the present invention. [Figure 7] This is a plan view of a hydraulic excavator, which is an example of a work machine according to the third embodiment of the present invention. [Figure 8] This is a side view showing the camera's field of view in a hydraulic excavator, which is an example of a work machine according to the third embodiment of the present invention. [Figure 9] This is a plan view of a hydraulic excavator, which is an example of a work machine according to the fourth embodiment of the present invention. [Figure 10] This is an example of an image captured by a camera in a hydraulic excavator, which is an example of a work machine according to the fifth embodiment of the present invention. [Modes for carrying out the invention]

[0029] Preferred embodiments of the present invention will be described with reference to the drawings.

[0030] <First Embodiment> Figures 1 and 2 are a side view and a top view of a hydraulic excavator 1, which is an example of a work machine equipped with a safety device according to the first embodiment of the present invention. The hydraulic excavator 1 comprises a lower traveling body 10 (lower body) that can travel on the ground G, an upper rotating body 12 (upper body) mounted on the lower traveling body 10 so as to be able to rotate around an axis extending in the vertical direction, a work device 14 (working member) mounted on the upper rotating body 12, and a work drive device.

[0031] The lower running body 10 comprises a pair of right crawlers 11R and left crawlers 11L, positioned on the right and left sides, respectively. Each of the right and left crawlers 11R and 11L operates to ensure that the lower running body 10 travels on the ground G.

[0032] The upper slewing body 12 includes a slewing frame 16 and a plurality of elements mounted thereon. The plurality of elements include an engine room 17 for housing the engine, a cab 18 which is the driver's cabin, and a counterweight 19 which constitutes the rear end of the upper slewing body 12.

[0033] The working device 14 includes a boom 21, an arm 22, and a bucket 24. The boom 21 is supported at the front end of the slewing frame 16 so as to be able to be raised and lowered. The arm 22 is connected to the tip of the boom 21 so as to be able to rotate vertically relative to the boom 21. The bucket 24 is a tip attachment for performing excavation work, etc., and is attached to the tip of the arm 22 so as to be able to rotate vertically relative to the arm 22. As shown in Figure 2, the working device 14 has a center line CA extending in the front-rear direction of the upper slewing body 12 and is supported by the upper slewing body 12 so as to be able to be raised and lowered. The cab 18 is located at the front end of the upper slewing body 12 and is positioned to the left of the working device 14.

[0034] Figure 3 shows the hydraulic circuit, multiple object detectors 60 (detection units), alarm 62, display device 64, and controller 70 (control unit) mounted on the hydraulic excavator 1. The controller 70 consists of, for example, a microcomputer and controls the operation of each element included in the hydraulic circuit. On the other hand, the controller 70 is electrically connected to the multiple object detectors 60, alarm 62 and display device 64 and together with them constitutes a safety device.

[0035] The hydraulic circuit includes a pump unit 30, a plurality of hydraulic actuators, a plurality of control valves, an operating device, a plurality of operating valves, and a plurality of pilot pressure sensors.

[0036] The pump unit 30 includes a plurality of hydraulic pumps, each of which includes at least one main pump and a pilot pump. The plurality of hydraulic pumps are connected to an engine (not shown) which is a power source, and are driven by the power output of the engine to discharge hydraulic fluid.

[0037] Each of the aforementioned hydraulic actuators receives hydraulic fluid from the pump unit 30 to move the movable parts of the hydraulic excavator, and includes a plurality of working hydraulic cylinders shown in Figure 1, namely a boom cylinder 26, an arm cylinder 27, and a bucket cylinder 28, and a slewing motor 32, a right travel motor 33, and a left travel motor 34 shown in Figure 3.

[0038] The boom cylinder 26 extends and retracts to raise and lower the boom 21 relative to the upper slewing body 12 when supplied with hydraulic fluid. The arm cylinder 27 extends and retracts to rotate the arm 22 relative to the boom 21 when supplied with hydraulic fluid. The bucket cylinder 28 extends and retracts to rotate the bucket 24 relative to the arm 22 when supplied with hydraulic fluid.

[0039] The slewing motor 32 includes a pair of right-slewing ports and left-slewing ports, and when hydraulic fluid is supplied to one of the right-slewing and left-slewing ports, it operates to rotate the upper slewing body 12 in the direction corresponding to that port (right-slewing direction or left-slewing direction).

[0040] The right travel motor 33 includes a pair of right forward ports and right reverse ports, and operates to move the right crawler 11R in the direction corresponding to the port (forward or reverse) when hydraulic fluid is supplied to one of the right forward or right reverse ports. Similarly, the left travel motor 34 includes a pair of left forward ports and left reverse ports, and operates to move the left crawler 11L in the direction corresponding to the port (forward or reverse) when hydraulic fluid is supplied to one of the left forward or left reverse ports.

[0041] The plurality of control valves are valves that open and close to enable control of the movement of each of the plurality of hydraulic actuators, and include the swing control valve 36, the right travel control valve 37, and the left travel control valve 38 shown in Figure 3.

[0042] The swivel control valve 36 is interposed between the pump unit 30 and the swivel motor 32 and opens and closes to change the direction and flow rate (swivel flow rate) of the hydraulic fluid supplied from the pump unit 30 to the swivel motor 32. The swivel control valve 36 is composed of a pilot-operated directional control valve including a right-swivel pilot port and a left-swivel pilot port. When pilot pressure is input to the right-swivel pilot port, the valve opens to allow hydraulic fluid to be supplied to the right-swivel port of the swivel motor 32 at a flow rate (right-swivel flow rate) corresponding to the magnitude of the pilot pressure. Conversely, when pilot pressure is input to the left-swivel pilot port, the valve opens to allow hydraulic fluid to be supplied to the left-swivel port of the swivel motor 32 at a flow rate (left-swivel flow rate) corresponding to the magnitude of the pilot pressure.

[0043] The right travel control valve 37 is interposed between the pump unit 30 and the right travel motor 33 and opens and closes to change the direction and flow rate (right travel flow rate) of the hydraulic fluid supplied from the pump unit 30 to the right travel motor 33. The right travel control valve 37 is composed of a pilot-operated directional control valve including a right forward pilot port and a right reverse pilot port. When pilot pressure is input to the right forward pilot port, the valve opens to allow hydraulic fluid to be supplied to the right forward port of the right travel motor 33 at a flow rate (right forward flow rate) corresponding to the magnitude of the pilot pressure. Conversely, when pilot pressure is input to the right reverse pilot port, the valve opens to allow hydraulic fluid to be supplied to the right reverse port of the right travel motor 33 at a flow rate (right reverse flow rate) corresponding to the magnitude of the pilot pressure.

[0044] The left travel control valve 38 is interposed between the pump unit 30 and the left travel motor 34 and opens and closes to change the direction and flow rate (left travel flow rate) of the hydraulic fluid supplied from the pump unit 30 to the left travel motor 34. The left travel control valve 38 is composed of a pilot-operated directional control valve including a left forward pilot port and a left reverse pilot port. When pilot pressure is input to the left forward pilot port, the valve opens to allow hydraulic fluid to be supplied to the left forward port of the left travel motor 34 at a flow rate (left forward flow rate) corresponding to the magnitude of the pilot pressure. Conversely, when pilot pressure is input to the left reverse pilot port, the valve opens to allow hydraulic fluid to be supplied to the left reverse port of the left travel motor 34 at a flow rate (left reverse flow rate) corresponding to the magnitude of the pilot pressure.

[0045] The aforementioned plurality of control valves also include boom control valves, arm control valves, and bucket control valves (not shown) provided for the boom cylinder 26, arm cylinder 27, and bucket cylinder 28, respectively.

[0046] The operating device receives an operation to move the hydraulic excavator and inputs an operation signal to the controller 70, and includes a plurality of actuators corresponding to each of the plurality of control valves. Each of the plurality of actuators is composed of a so-called remote control valve connected to the pilot pump, and opens to allow the pilot pressure corresponding to the operation given to the remote control valve to be supplied to the corresponding control valve.

[0047] The operations provided to the control device include controlled operations that are subject to safety control. In this embodiment, these controlled operations include a rotation operation to rotate the upper rotating body 12 relative to the lower traveling body 10, and right and left travel operations to move the right and left crawlers 11R and 11L, respectively. These right and left travel operations correspond to travel operations that cause the lower traveling body 10 to perform a travel motion.

[0048] Figure 3 shows the rotation control device 42, the right travel control device 43, and the left travel control device 44, which are among the plurality of control devices to which the controlled operation is assigned.

[0049] The slewing control device 42 includes a slewing lever and a slewing pilot valve connected thereto, which opens to supply a pilot pressure corresponding to the magnitude of the slewing operation to the pilot port of the slewing control valve 36, which corresponds to the direction of the slewing operation applied to the slewing lever, among the right slewing and left slewing pilot ports of the slewing control valve 36. The right travel control device 43 includes a right travel lever and a right travel pilot valve connected thereto, which opens to supply a pilot pressure corresponding to the magnitude of the right travel operation to the pilot port of the right travel control valve 37, which corresponds to the direction of the right travel operation applied to the right travel lever, among the right forward and left forward pilot ports of the right travel control valve 37. Similarly, the left travel control device 44 includes a left travel lever and a left travel pilot valve connected thereto, which opens to supply a pilot pressure corresponding to the magnitude of the left travel operation to the pilot port of the left travel control valve 38, which corresponds to the direction of the left travel operation applied to the left travel lever, among the left forward and left forward pilot ports of the left travel control valve 38.

[0050] The aforementioned plurality of operating devices include, in addition to the slewing operating device 42 and the right and left travel operating devices 43 and 44, a boom operating device that receives boom operation to move the boom 21 and allows the supply of pilot pressure to the boom control valve, an arm operating device that receives arm operation to move the arm 22 and allows the supply of pilot pressure to the arm control valve, and a bucket operating device that receives bucket operation to move the bucket 24 and allows the supply of pilot pressure to the bucket control valve. The boom operation, the arm operation, and the bucket operation are all operations for moving the work device 14.

[0051] The plurality of operating valves are interposed between the swivel control valve 42, the right travel control valve 43, and the left travel control valve 44, and the corresponding swivel control valve 36, the right travel control valve 37, and the left travel control valve 38, respectively, enabling the controller 70 to limit the swivel pilot pressure and the right and left travel pilot pressures. Specifically, each of the plurality of operating valves is composed of an electromagnetic pressure reducing valve, and the pressure reducing valve limits the pilot pressure to a degree corresponding to the limiting command input to the pressure reducing valve. In this embodiment, each of the pressure reducing valves is an inversely proportional electromagnetic pressure reducing valve, and the pilot pressure is limited to a greater degree the larger the limiting command. The pressure reducing valve may also be an electromagnetic proportional pressure reducing valve.

[0052] Specifically, the plurality of control valves include the right-turn control valve 46R and left-turn control valve 46L shown in Figure 3, the right-forward travel control valve 47F and the right-reverse travel control valve 47B, and the left-forward travel control valve 48F and the left-reverse travel control valve 48B.

[0053] The right-turn control valve 46R is interposed between the swivel actuator 42 and the right-turn pilot port of the swivel control valve 36, and operates to limit the right-turn pilot pressure input from the swivel actuator 42 to the right-turn pilot port to a degree corresponding to the right-turn limit command input from the controller 70 to the right-turn control valve 46R. Similarly, the left-turn control valve 46L is interposed between the swivel actuator 42 and the left-turn pilot port of the swivel control valve 36, and operates to limit the left-turn pilot pressure input from the swivel actuator 42 to the left-turn pilot port to a degree corresponding to the left-turn limit command input from the controller 70 to the left-turn control valve 46L.

[0054] The right forward travel control valve 47F is interposed between the right travel control device 43 and the right forward pilot port of the right travel control valve 37, and operates to limit the right forward pilot pressure input from the right travel control device 43 to the right forward pilot port to a degree corresponding to the right forward travel restriction command input from the controller 70 to the right forward travel control valve 47F. Similarly, the right reverse travel control valve 47R is interposed between the right travel control device 43 and the right reverse pilot port of the right travel control valve 37, and operates to limit the right reverse pilot pressure input from the right travel control device 43 to the right reverse pilot port to a degree corresponding to the right reverse travel restriction command input from the controller 70 to the right reverse travel control valve 47R.

[0055] The left forward travel control valve 48F is interposed between the left travel control device 44 and the left forward pilot port of the left travel control valve 38, and operates to limit the left forward pilot pressure input from the left travel control device 44 to the left forward travel limit command input from the controller 70 to the left forward travel control valve 48F to a degree corresponding to the left forward travel limit command. Similarly, the left reverse travel control valve 48R is interposed between the left travel control device 44 and the left reverse pilot port of the left travel control valve 38, and operates to limit the left reverse pilot pressure input from the left travel control device 44 to the left reverse pilot port to a degree corresponding to the left reverse travel limit command input from the controller 70 to the left reverse travel control valve 48R.

[0056] Each of the plurality of pilot pressure sensors is an operation amount detector that detects the magnitude (operation amount) of the turning operation, the rightward travel operation, and the leftward travel operation, respectively. Specifically, each of the plurality of pilot pressure sensors is composed of a pressure sensor that detects the pilot pressure input to the turning control valve 36, the rightward travel control valve 37, and the leftward travel control valve 38, respectively, and inputs a detection signal corresponding to the magnitude of the pilot pressure, that is, a detection signal corresponding to the target operation amount, to the controller 70. Specifically, the plurality of pilot pressure sensors include a right-turn pilot pressure sensor 52R that detects the right-turn pilot pressure, a left-turn pilot pressure sensor 52L that detects the left-turn pilot pressure sensor, a right-forward pilot pressure sensor 53F that detects the right-forward pilot pressure, a right-reverse pilot pressure sensor 53B that detects the right-reverse pilot pressure, a left-forward pilot pressure sensor 54F that detects the left-forward pilot pressure, and a left-reverse pilot pressure sensor 54B that detects the left-reverse pilot pressure.

[0057] In the hydraulic circuit, the swing motor 32, swing control valve 36, and right and left swing operation valves 46R and 46L, together with the pump unit 30, constitute a swing drive circuit for swinging the upper swing body 12. Similarly, the right travel motor 33, right travel control valve 37, and right forward and right reverse travel operation valves 47F and 47B, together with the pump unit 30, constitute a right travel drive circuit for moving the right crawler 11R, and the left travel motor 34, left travel control valve 38, and left forward and left reverse travel operation valves 48F and 48B, together with the pump unit 30, constitute a left travel drive circuit for moving the left crawler 11L.

[0058] Each of the multiple object detectors is positioned at a specific location on the hydraulic excavator and detects objects present around the excavator. They generate a detection signal that enables the acquisition of positional information, including the distance from the specific location to the object, and input this signal to the controller 70. In this embodiment, each of the multiple object detectors is composed of an imaging device such as a monocular camera or a stereo camera, and generates an image including the object. In other embodiments, each object detector may be a sensor such as an ultrasonic sensor, an infrared laser, or a millimeter-wave radar.

[0059] Specifically, the plurality of object detectors (detection units) according to this embodiment are arranged on the upper slewing body 12 so as to be able to detect objects around the hydraulic excavator 1, and include the front object detector 60A, right object detector 60R, left object detector 60L, and rear object detector 60B shown in Figure 2. The front object detector 60A is positioned at the right front end of the upper slewing body 12 so as to be able to detect objects located in front of the upper slewing body 12. The right object detector 60R is positioned on the right side of the upper slewing body 12 so as to be able to detect objects located at least to the right of the upper slewing body 12, the left object detector 60L is positioned on the left side of the upper slewing body 12 so as to be able to detect objects located at least to the left of the upper slewing body 12, and the rear object detector 60B is positioned at the rear end of the upper slewing body 12 so as to be able to detect objects located at least behind the upper slewing body 12.

[0060] The alarm device 62 issues an alarm when an alarm command is input from the controller 70. The alarm device 62 may be an audible alarm, such as a buzzer, or an illuminating alarm, such as an alarm lamp.

[0061] The display device 64 has a screen capable of displaying surrounding images including the object to be detected, and is positioned inside the cab 18 so that the operator can view the screen. The display device 64 displays an image corresponding to the display command signal input from the controller 70.

[0062] The controller 70 determines the presence or absence of an object to be detected around the hydraulic excavator 1 based on the image signals input from each of the object detectors 60A, 60R, 60L, and 60B, and executes a predetermined safety control when the object to be detected enters a preset monitoring area.

[0063] The safety control includes speed limit control, alarm control, and display control. The speed limit control is a control that limits (reduces) the speed of a preset restricted operation among the operations of the hydraulic excavator 1 according to the detection distance, and may include a control that sets the speed to 0, i.e., a stop control that forcibly stops the restricted operation. In this embodiment, the restricted operation includes at least the rotation operation of the upper slewing body 12 relative to the lower traveling body 10, and depending on the situation, also includes the travel operation of the right crawler 11R and the left crawler 11L. Alternatively, the restricted operation may also include the operation of the work device 14, for example, the luffing operation of the boom 21 and the rotation operation of the arm 22. The alarm control is a control that causes the alarm device 62 to issue the alarm based on the detection of the object to be detected. The display control is a control that causes the display device 64 to display a warning image based on the detection of the object to be detected. The warning image is, for example, an image taken by each of the object detectors 60A, 60R, 60L, and 60B, and is a surrounding image including the object to be detected.

[0064] The controller 70 determines whether the detected object has entered the monitoring area, which is set relative to the upper rotating body 12, based on the detection result of the object detector 60, and executes various safety controls according to the determination result. The controller 70 has multiple functions as shown in Figure 4 for executing safety controls, and these multiple functions include a position information generation unit 72, a safety control determination unit 74, a rotation restriction command unit 76, a travel restriction command unit 78, an alarm command unit 82, and a display command unit 84. These functions are realized, for example, by the CPU included in the controller 70 executing a program that is pre-stored in the memory included in the controller 70.

[0065] The position information generation unit 72 periodically (specifically, every time a preset sampling period has elapsed) acquires image signals input from each of the object detectors 60A, 60R, 60L, and 60B, and processes these image signals to determine whether or not there is a detection target object within the shooting range of the object detectors 60A, 60R, 60L, and 60B, and, if there is a detection target object, it identifies a distance value corresponding to the distance of the detection target object from the reference position (in this embodiment, the position where each of the object detectors 60A, 60R, 60L, and 60B is positioned), i.e., the detection distance, and generates position information including the position of the detection target object and the distance value. In other words, the position information generation unit 72, together with the object detectors 60A, 60R, 60L, and 60B, constitutes a position information acquisition unit that periodically acquires position information. The detection target object preferably includes at least a person (worker), but may also include objects other than people.

[0066] The safety control determination unit 74 determines whether safety control is necessary and the content of the safety control based on the location information generated by the location information generation unit 72. Specifically, if the safety control determination unit 74 in this embodiment determines that safety control is necessary, it identifies the operation for which speed restrictions should be imposed and determines the degree of speed restriction for the restricted operation corresponding to the detection distance. Speed ​​restrictions include forced stops.

[0067] The Swing Restriction Command Unit 76 generates a Swing Restriction Command signal. The Swing Restriction Command signal is a signal for executing a Swing Restriction Control among the safety controls determined by the Safety Control Determination Unit 74. Specifically, when a control that restricts the speed of a right turn or left turn is identified, the signal is for restricting the speed (turn speed) to the degree of restriction determined for that speed (including forced stopping). The Swing Restriction Command Unit 76 inputs the Swing Restriction Command signal to the operating valve corresponding to the restricted operation among the right turn operating valve 46R and the left turn operating valve 46L (right turn operating valve 46R if the right turn operation is restricted).

[0068] The driving restriction command unit 78 generates a driving restriction command signal. The driving restriction command signal is a signal for executing driving restriction control among the safety controls determined by the safety control determination unit 74. Specifically, when a control that limits the speed of forward driving or reverse driving is identified, the signal is for limiting the speed (driving speed) to the degree of restriction determined for that speed (driving speed) (including forced stopping). The driving restriction command unit 78 inputs the turning restriction command signal to the operating valves corresponding to the restricted operation to be restricted from among the right forward driving operating valve 47F, right reverse driving operating valve 47B, left forward driving operating valve 48F, and left reverse driving operating valve 48B (right reverse driving operating valve 47B and left forward driving operating valve 48B if reverse driving is restricted).

[0069] The alarm command unit 82 generates an alarm command signal when the safety control determination unit 74 determines that safety control is necessary, and inputs the alarm command signal to the alarm device 62 to cause the alarm device 62 to issue an alarm.

[0070] The display command unit 84 generates a display command signal when the safety control determination unit 74 determines that safety control is necessary, and inputs the display command signal to the display device 64, thereby displaying a warning image on the display device 64.

[0071] Referring to Figure 2, in this embodiment, multiple monitoring areas are set around the upper rotating body 12 as a reference. Specifically, the monitoring areas include a first stop area A1 (first monitoring area), a second stop area A2, a first deceleration area B1 (second monitoring area), a second deceleration area B2, and a third deceleration area B3.

[0072] The first stopping area A1 is set to extend along the work device 14 on the right side of the upper rotating body 12. In this embodiment, the first stopping area A1 has a trapezoidal shape that extends long in the front-rear direction when viewed from above. The first stopping area A1 includes a first outer edge A1R and a first inner edge A1L. The first outer edge A1R defines the outer (right) side of the first stopping area A1 and extends in the front-rear direction of the upper rotating body 12. Similarly, the first inner edge A1L defines the inner (left) side of the first stopping area A1 and extends in the front-rear direction of the upper rotating body 12. When the forward object detector 60A detects that an object to be detected has entered the first stopping area A1, the controller 70 forcibly stops at least the driving of the work device 14, the rightward rotation of the upper rotating body 12, and the forward movement of the lower traveling body 10. In the above definition, the inner and outer positions are defined as the position closer to the working device 14 (inner) and the position further away (outer).

[0073] As shown in Figure 2, the second stopping area A2 is formed on both the left and right sides and rear of the upper rotating body 12 and has a U-shape in plan view. The second stopping area A2 includes the rear stopping area A21 behind the upper rotating body 12, the left stopping area A22 to the left of the upper rotating body 12, and the right stopping area A23 to the right of the upper rotating body 12. When the rear object detector 60B, the right object detector 60R, and the left object detector 60L detect that an object to be detected has entered the second stopping area A2, the controller 70 forcibly stops at least the left and right rotation movement of the upper rotating body 12 and the reverse movement of the lower traveling body 10.

[0074] The first deceleration region B1 is located on the opposite side of the working device 14 when viewed from the first stopping region A1 in a plan view, and is positioned to be tangent to the first stopping region A1 with the first outer edge A1R as its boundary. The first deceleration region B1 has a trapezoidal shape that extends long in the front-rear direction in a plan view. The first deceleration region B1 includes a second outer edge B1R and a second inner edge B1L. The second outer edge B1R defines the outer (right) side of the first deceleration region B1 and extends in the front-rear direction of the upper rotating body 12. Similarly, the second inner edge B1L defines the inner (left) side of the first deceleration region B1 and extends in the front-rear direction of the upper rotating body 12. The second inner edge B1L is positioned to overlap with the first outer edge A1R. When the forward object detector 60A detects that the object to be detected has entered the first deceleration region B1, the controller 70 decelerates at least the rightward rotation of the upper rotating body 12.

[0075] As shown in Figure 2, the second deceleration area B2 and the third deceleration area B3 are located to the left and right outside the left stopping area A22 and the right stopping area A23. When the left object detector 60L or the right object detector 60R detects that an object to be detected has entered the second deceleration area B2 or the third deceleration area B3, the controller 70 decelerates the left and right rotational movement of at least the upper rotating body 12.

[0076] Figure 5 is a graph showing the results of object detection by a camera, which is an example of an object detector 60 according to this embodiment. Figure 5 shows the detection results of a front object detector 60A mounted on the front side of the upper rotating body 12. The horizontal axis of Figure 5 shows the distance from the front object detector 60A in the left-right direction (X distance), and the vertical axis shows the distance from the front object detector 60A in the front-back direction (Y distance). An object detector, such as a camera, has a detection range (field of view) centered on a central axis CL that extends away from the object detector. This detection range has a conical shape with its apex at the position of zero on the horizontal axis and zero on the vertical axis of Figure 5. As shown in Figure 2, when the front object detector 60A is mounted on the front end of the upper rotating body 12, the central axis CL is positioned to extend forward from the upper rotating body 12 in a plan view.

[0077] In Figure 5, the cluster of black dots represents the measured distance from the object detector 60A to the object, and the white circles nearby indicate the measurement points of the same object by the object detector 60A. As shown in Figure 5, in the central region CP near the central axis CL, the error between the measured value and the measurement point is smaller, and the object can be detected with higher accuracy than in the right region RP to the right of the central axis CL and the left region LP to the left of the central axis CL. In the case of a camera, this error is due to the increase in lens distortion and the decrease in the number of pixels per unit angle as the distance from the central axis CL to the left and right increases. Therefore, in order to detect an object with high accuracy using the object detector 60, it is desirable to suitably utilize the area between the right region RP and the left region LP with the central region CP as the center in Figure 5, and in particular, detection within a range of ±0.5m to the left and right of the central axis CL is especially desirable.

[0078] Referring to Figure 2, in this embodiment, the front object detector 60A is mounted on the upper rotating body 12 such that, in a plan view, it is on the opposite side of the cab 18 from the center line CA of the work device 14, and its central axis CL extends along the center line CA. The monitoring area set by the controller 70 includes the first stop area A1 (first monitoring area). The first outer edge A1R of the first stop area A1 extends along the central axis CL on the side of the front object detector 60A that is on the work device 14 side in a plan view.

[0079] Therefore, for example, if the upper rotating body 12 rotates to the right while a worker is on the ground to the right of the work device 14, the worker enters the first deceleration region B1 as the upper rotating body 12 rotates, and then enters the first stopping region A1. At this time, since the central axis CL of the front object detector 60A is positioned along the first outer edge A1R of the first stopping region A1, the front object detector 60A can detect the worker with high accuracy at the moment the worker crosses the first outer edge A1R. Therefore, the control to stop the rotation operation can be activated without delay.

[0080] Thus, in this embodiment, by defining the relative positional relationship between the central axis CL of the front object detector 60A and the first outer edge A1R of the first stop area A1, the front object detector 60A can detect objects with particularly high accuracy around the first outer edge A1R, and interference between the work device 14 and the object being detected in an area that is difficult for the operator operating the hydraulic excavator 1 inside the cab 18 to see can be stably suppressed by safety control. In particular, by aligning the central axis CL of the front object detector 60A with the upstream side edge, i.e., the first outer edge A1R, when the object being detected enters the first stop area A1 as the upper rotating body 12 rotates, the entry of the object being detected into the first stop area A1 can be detected with high accuracy. As mentioned above, in order to effectively utilize the detection accuracy of the front object detector 60A, it is desirable that the first outer edge A1R be included within a range of ±0.5m in the left-right direction with respect to the central axis CL.

[0081] Furthermore, in this embodiment, since the first outer edge A1R of the first stopping region A1 and the central axis CL of the front object detector 60A are set parallel to each other, the front object detector 60A can detect the object with particularly high accuracy around the first outer edge A1R, regardless of the distance from the upper rotating body 12 of the object to be detected, at both short and long distances.

[0082] Furthermore, in this embodiment, since the first stopping area A1 is set such that the first outer edge A1R and the central axis CL overlap in a plan view, it becomes possible to detect the object with even higher accuracy regardless of the distance from the upper rotating body 12 of the object to be detected.

[0083] Furthermore, in this embodiment, as the object to be detected enters the first stopping area A1 from the first outer edge A1R, the operation of the hydraulic excavator 1, particularly the rotational movement of the upper rotating body 12, is stopped. Therefore, interference between the object to be detected and the hydraulic excavator 1, especially the working device 14, can be prevented with high precision.

[0084] In addition, in this embodiment, the monitoring area further includes a first deceleration area B1 (second monitoring area) which is located on the opposite side of the work device 14 when viewed from the first stop area A1 in a plan view, and is in contact with the first stop area A1 with the first outer edge A1R as the boundary. By arranging the first deceleration area B1 outside the first stop area A1 in this way, interference between the object to be detected and the hydraulic excavator 1 can be prevented in stages.

[0085] In particular, as the object being detected enters the first deceleration region B1, the operation of the hydraulic excavator 1, especially the rotational movement of the upper rotating body 12, is decelerated, which allows for more reliable stopping control in the subsequent first stopping region A1.

[0086] <Second Embodiment> Next, a safety device for a work machine according to a second embodiment of the present invention will be described. Figure 6 is a plan view of a hydraulic excavator 1, which is an example of a work machine according to this embodiment. In the first embodiment described above, the first stopping area A1 was set so that the first outer edge A1R is parallel to the front-rear direction of the upper slewing body 12. However, as shown in Figure 6, when the work device 14 includes a base end supported by the upper slewing body 12 and a tip end opposite to the base end, the first outer edge A1R may extend away from the center line CA as it moves forward of the upper slewing body 12 in a plan view.

[0087] In this case, as shown in Figure 6, the front object detector 60A is also installed at a slight inclination toward the right front, and its central axis CL is positioned along the first outer edge A1R. By setting the width in the left-right direction of the part of the first stopping area A1 that is farther from the upper rotating body 12 to be wider than the width in the left-right direction of the part that is closer to the upper rotating body 12, interference between the tip of the work device 14, which has a high peripheral speed when rotating, and the object to be detected can be reliably prevented.

[0088] Furthermore, in this embodiment, as shown in Figure 6, it becomes possible to position the first stopping area A1 around the tip of the working device 14 to extend beyond the vehicle width of the upper rotating body 12.

[0089] <Third Embodiment> Next, a safety device for a work machine according to a third embodiment of the present invention will be described. Figure 7 is a plan view of a hydraulic excavator 1, which is an example of a work machine according to this embodiment. Figure 8 is a side view showing the field of view of the camera of the front object detector 60A in the hydraulic excavator 1 according to this embodiment.

[0090] In this embodiment, there is a difference in the installation of the front object detector 60A compared to the second embodiment described above. Specifically, as shown in Figure 7, in a plan view, the first outer edge A1R extends away from the center line CA as it moves forward of the upper rotating body 12, while the central axis CL of the front object detector 60A extends along the front-rear direction of the upper rotating body 12. The first stopping area A1 is set such that the first outer edge A1R intersects the central axis CL in the area adjacent to the tip of the work device 14.

[0091] With this configuration, the first outer edge A1R and the central axis CL intersect around the tip of the work device 14, making it possible to improve the detection accuracy of objects to be detected in this area, and particularly suppressing interference between the tip, where the peripheral speed is highest due to the rotational movement of the upper rotating body 12, and the object to be detected. In this embodiment as well, it is desirable that the distance between the region of the first outer edge A1R closest to the upper rotating body 12 and the central axis CL be set to within ±0.5m.

[0092] In this embodiment and the previous second embodiment, taking into account that the rotational movement of the upper slewing body 12 is less likely to stop due to inertia when the working device 14 is in the position where it extends the furthest forward (maximum reach position), the width of the first stopping area A1 in the left-right direction is set to be large at the tip of the working device 14. On the other hand, in the area close to the upper slewing body 12, the width of the first stopping area A1 in the left-right direction is reduced to prevent the safety control from being activated unnecessarily and to avoid impairing the workability of the hydraulic excavator 1.

[0093] In Figure 7, there is concern that the region close to the upper rotating body 12 is susceptible to lens distortion and other effects because the first outer edge A1R and the central axis CL are far apart. However, as shown in Figure 8, the number of pixels per unit angle is higher (higher resolution) in this region compared to the area around the tip of the work device 14 (the region far from the upper rotating body 12), so the detection accuracy (distance measurement accuracy) is less likely to decrease. For example, when the front object detector 60A is installed at a predetermined height and elevation angle on the front end of the upper rotating body 12, the difference in the number of pixels is α = 185Px in the section 1 to 2m in front of the front object detector 60A, while in the section 9 to 10m, the difference in the number of pixels is β = 15Px. This shows that the resolution of the front object detector 60A is higher in the region close to the upper rotating body 12 than in the region farther away, so safety can be ensured even if the lateral width of the region close to the upper rotating body 12 is reduced.

[0094] <Fourth Embodiment> Next, a safety device for a work machine according to the fourth embodiment of the present invention will be described. Figure 9 is a plan view of a hydraulic excavator 1, which is an example of a work machine according to this embodiment. This embodiment differs from the first embodiment in that the object detector 60 further has a sub-pre-object detector 60C (sub-detection unit), and the monitoring area further has a third stop area A3 and a fourth deceleration area B4.

[0095] The secondary front object detector 60C has a secondary detection range centered on a secondary central axis CM that extends away from the secondary detection unit in a plan view. The secondary front object detector 60C is mounted on the upper rotating body 12 such that, in a plan view, it is on the same side as the cab 18 with respect to the center line CA of the work device 14, and the secondary central axis CM extends along the center line CA.

[0096] The third stopping area A3 (sub-monitoring area) is located to the left of the work device 14, i.e., on the same side as the cab 18. The third stopping area A3 has a third outer edge A3L and a third inner edge A3R. The third outer edge A3L extends along the central axis (sub-central axis CM) of the sub-front object detector 60C, on the side of the sub-front object detector 60C that is closer to the work device 14 in a plan view. The third inner edge A3R is located closer to the work device 14 than the third outer edge A3L. The third outer edge A3L and the third inner edge A3R extend along the front-rear direction of the upper rotating body 12. The function of the third stopping area A3 is the same as that of the first stopping area A1.

[0097] The fourth deceleration region B4 is located adjacent to the left side of the third stopping region A3. The fourth deceleration region B4 has a fourth outer edge B4L and a fourth inner edge B4R. The fourth inner edge B4R is positioned to overlap with the third outer edge A3L. The fourth outer edge B4L is located to the left of the fourth inner edge B4R. The fourth outer edge B4L and the fourth inner edge B4R extend along the longitudinal direction of the upper rotating body 12. The function of the fourth deceleration region B4 is the same as that of the first deceleration region B1.

[0098] Thus, in this embodiment, the sub-object detector 60C is mounted on the same side of the upper rotating body 12 as the cab 18 relative to the working device 14, enabling safety control for detected objects on both the left and right sides of the working device 14. As a result, the safety of the hydraulic excavator 1 can be further enhanced.

[0099] Furthermore, in this embodiment, as shown in Figure 9, the width of the third stop area A3 (sub-monitoring area) is set smaller than the width of the first stop area A1 (first monitoring area) in the left-right direction of the upper rotating body 12. By setting the width of the third stop area A3 to be relatively smaller in this way, it is possible to perform safety control for the object to be detected on both the left and right sides of the work device 14 while suppressing excessive activation of safety control in the area (third stop area A3) that is easily visible to the operator inside the cab 18.

[0100] <Fifth Embodiment> Next, a safety device for a work machine according to the fifth embodiment of the present invention will be described. Figure 10 is an example of an image taken by the camera of the front object detector 60A in a hydraulic excavator 1, which is an example of a work machine according to this embodiment. In this embodiment, there is a difference in the setting range of the first stop area A1 compared to the fourth embodiment described above. In this embodiment, as shown in Figure 4, the safety device further includes an input unit 90 (monitoring area switching unit). The input unit 90 receives predetermined information from, for example, an operator inside the cab 18. The information is for switching the range of the first stop area A1. Specifically, the information allows switching between a state in which the first stop area A1 includes an area that overlaps with the work device 14 in a plan view, and a state in which the first stop area A1 does not include an area that overlaps with the work device 14 in a plan view.

[0101] In Figure 9, the first stop area A1 is set to the right of the work device 14, and the third stop area A3 is set to the left of the work device 14, with no monitoring area set below the work device 14. On the other hand, as shown in image I taken by the camera of the front object detector 60A in Figure 10, the first stop area A1 can include the work device lower area A4 depending on the switching information input to the input unit 90. In this case, even if a person H (worker) is located in the work device lower area A4 below the work device 14, the controller 70 can perform safety control. The control by the controller 70 may include control of the rotation of the boom 21, arm 22, and bucket 24, in addition to control of the slewing and traveling operations.

[0102] Thus, in this embodiment, it is possible to switch the range of the first stop area A1 depending on the conditions of the work site, either by activating safety control in the area below the work device 14 or by prohibiting the activation of safety control in that area. In particular, when changing the tip attachment such as the bucket 24, when reinforcing the underside of the arm 22, or when paint peels off from the work device 14, false detection by the front object detector 60A may occur. In this case, the operator would want to prohibit the activation of safety control in that area. On the other hand, if there is an obstacle below the work device 14, it is necessary to prevent interference between the work device 14 and the obstacle. In this embodiment, since it is possible to select whether or not to execute safety control in the area A4 below the work device according to the needs of the work site, it is also possible to prevent impairing the operability of the hydraulic excavator 1.

[0103] The present invention is not limited to the embodiments described above. The present invention encompasses, for example, the following embodiments.

[0104] The positional information for detecting an object may be any information relating to the relative position of the object to be detected with respect to a reference position set for the work machine, and may include only information relating to the distance of the object from the reference position, or it may include other information. For example, a slewing angle sensor may be provided to detect the slewing angle of the upper slewing body 12 relative to the lower traveling body 10, and the position coordinates of the object to be detected may be determined based on the slewing angle detected by the slewing angle sensor.

[0105] Furthermore, the reference position does not necessarily have to be the installation location of the object detector (i.e., the distance does not have to be the distance from the object detector to the object to be detected), but may be another part of the work machine or a position set around the work machine. For example, the part of the work machine closest to the object to be detected may be identified based on the detection signal generated by the object detector, and the position of that part may be set as the reference position. In other words, the reference position may be set so that the shortest distance is always calculated as the distance.

[0106] Furthermore, the detection unit according to the present invention is not limited to those including an imaging device such as a camera. For example, if there are no special limitations on the object to be detected (i.e., when it is not necessary to identify the object to be detected), the object detector may be a distance detector such as an infrared depth sensor or millimeter-wave radar. Alternatively, it may be an imaging device capable of generating three-dimensional information, such as a stereo camera, rather than a monocular camera.

[0107] In the present invention, when speed limit control is performed, the specific means for performing the speed limit control are not limited. For example, in a work machine in which the slewing control device 42 and the travel control devices 43, 44 are electric lever devices, that is, devices that generate an electrical signal corresponding to an operation input by an operator and input it to a controller, and the controller is configured to operate solenoid valves interposed between the pilot hydraulic power source and control valves (e.g., slewing control valve 36 and travel control valves 37, 38) based on the electrical signal, the speed limit (i.e., reducing the actual speed to a speed lower than the speed corresponding to the operation) may be performed by changing the command input to the solenoid valve.

[0108] In the above embodiment, the operation of the hydraulic excavator 1 was described as being forcibly stopped in the first stopping area A1, but it is also possible to issue the alarm or the like when an object is detected in an area similar to the first stopping area A1. Furthermore, each deceleration area B1 to B3 does not need to be set. [Explanation of symbols]

[0109] 1. Hydraulic excavator (working machine) 10 Lower running body (lower main body) 12. Upper rotating body (upper main body) 14 Working equipment 60 Object Detectors 60A Front object detector (detection unit) 60B Rear Object Detector 60C Sub-object detector 60R Right Object Detector 60L Left Object Detector 70 Control Department A1 First Stop Area (First Surveillance Area) A1R 1st outer side A1L 1st inner side A2 Second Stop Area A3 Third Stop Area (Secondary Surveillance Area) B1 First deceleration zone (Second surveillance zone) B2 Second Deceleration Zone B3 Third Deceleration Zone CA Centerline CL central axis

Claims

1. A safety device for industrial machinery, A detection unit capable of detecting objects around the aforementioned work machine, the detection unit having a detection range centered on a central axis extending away from the detection unit in a plan view, and having the characteristic that the detection error increases as it moves away from the central axis, The system includes a control unit that determines whether the object has entered a monitoring area set relative to the upper body of the work machine based on the detection result of the detection unit, and executes safety control according to the determination result, The detection unit is mounted on the upper body such that, in a plan view, its central axis extends along the center line with respect to the center line of the working member of the working machine, on the opposite side of the cab of the working machine. The monitoring area includes a first monitoring area having a first outer edge that extends along the central axis on the side of the detection unit that is closer to the work member in a plan view, A safety device for a work machine, wherein the first monitoring area is set such that, in a plan view, the first outer edge and the central axis are parallel, and the first outer edge is included within a range of ±0.5 m in the left-right direction with respect to the central axis.

2. The safety device for a work machine according to claim 1, wherein the first monitoring area is set such that the first outer edge and the central axis overlap in a plan view.

3. A safety device for a work machine, A detection unit capable of detecting objects around the aforementioned work machine, the detection unit having a detection range centered on a central axis extending away from the detection unit in a plan view, and having the characteristic that the detection error increases as it moves away from the central axis, The system includes a control unit that determines whether the object has entered a monitoring area set relative to the upper body of the work machine based on the detection result of the detection unit, and executes safety control according to the determination result, The detection unit is mounted on the upper body such that, in a plan view, its central axis extends along the center line with respect to the center line of the working member of the working machine, on the opposite side of the cab of the working machine. The working member includes a base end supported by the upper body and a tip end opposite to the base end, The monitoring area includes a first monitoring area having a first outer edge that extends along the central axis on the side of the detection unit that is closer to the work member in a plan view, A safety device for a work machine, wherein, in a plan view, the first outer edge extends away from the center line as it moves forward of the upper body, and the first monitoring area is set such that it intersects the central axis in the area adjacent to the tip of the work member.

4. A safety device for a work machine, A detection unit capable of detecting objects around the aforementioned work machine, the detection unit having a detection range centered on a central axis extending away from the detection unit in a plan view, and having the characteristic that the detection error increases as it moves away from the central axis, The system includes a control unit that determines whether the object has entered a monitoring area set relative to the upper body of the work machine based on the detection result of the detection unit, and executes safety control according to the determination result, The detection unit is mounted on the upper body at an angle such that, in a plan view, it is on the opposite side of the cab of the work machine with respect to the center line of the work member of the work machine, and the central axis moves away from the center line as it advances forward of the upper body. The monitoring area includes a first monitoring area having a first outer edge that extends along the central axis on the side of the detection unit that is closer to the work member in a plan view, A safety device for a work machine, wherein, in a plan view, the first monitoring area is set such that the first outer edge moves away from the center line as it advances forward of the upper body.

5. The safety device for a work machine according to any one of claims 1 to 4, wherein the control unit determines, based on the detection result of the detection unit, that the object has entered the first monitoring area, and as a safety control, stops a predetermined operation of the work machine.

6. The safety device for a work machine according to any one of claims 1 to 4, wherein the monitoring area is located on the opposite side of the work member when viewed from the first monitoring area in a plan view, and further includes a second monitoring area that is in contact with the first monitoring area with the first outer edge as the boundary.

7. The safety device for a work machine according to claim 6, wherein the control unit determines, based on the detection result of the detection unit, that the object has entered the first monitoring area, and stops a predetermined operation of the work machine as a safety control, and determines, that the object has entered the second monitoring area, and slows down a predetermined operation of the work machine as a safety control.

8. A sub-detection unit capable of detecting objects in the vicinity of the aforementioned work machine, further comprising a sub-detection unit having a sub-detection range centered on a sub-central axis that extends in a direction away from the sub-detection unit in a plan view, The sub-detection unit is mounted on the upper body such that, in a plan view, it is on the same side as the cab with respect to the center line, and the sub-center axis extends along the center line. The safety device for a work machine according to any one of claims 1 to 4, wherein the monitoring area further includes a sub-monitoring area that extends along the sub-central axis on the side of the sub-detection unit side of the work member in a plan view.

9. The safety device for a work machine according to claim 8, wherein the width of the sub-monitoring area is set to be smaller than the width of the first monitoring area in the left-right direction of the upper body.

10. The safety device for a work machine according to any one of claims 1 to 4, further comprising a monitoring area switching unit capable of switching between a state in which the first monitoring area includes an area that overlaps with the work member in a plan view, and a state in which the first monitoring area does not include an area that overlaps with the work member in a plan view.

Images