Working machinery

Abstract

To provide a work machine that can suppress the load placed on the work machine during breaker work. [Solution] The hydraulic excavator 1 is equipped with a controller 10 that generates an overhead view image of the area around the slewing body 3 using images captured by multiple cameras 13 and displays it on a display 21, and a front work device 4 having a breaker 5. A reference point 5x, which serves as the basis for attitude calculation, is set in the breaker 5. Based on the attitude state of the boom 6 detected by the sensor 6b, the controller 10 sets a first boundary 28, which is the boundary of the allowable working range 32 of the breaker 5, at a position closer to the slewing body 3 than the position reached by the reference point 5x when the arm cylinder 7a that drives the arm 7 reaches the stroke end on the arm dump side, and displays the first boundary 28 on the overhead view image, and also displays a reference image 99 at a position corresponding to the position of the reference point 5x calculated based on the sensor's detected value on the overhead view image.

Description

Technical Field

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

Background Art

[0002] Work machines represented by hydraulic excavators are used for a wide variety of works by attaching various attachments such as buckets, large breakers, small breakers, grapples, and magnets to the tip of a front working device which is an articulated work arm. One type of such attachments is a hydraulic breaker (sometimes simply referred to as a breaker) that crushes concrete structures, rocks, and bedrock by striking with a chisel.

[0003] By the way, since work machines require simultaneous operation of a plurality of actuators, a high level of skilled technique is required of an operator to achieve both work efficiency and accuracy. Therefore, in order to achieve both work efficiency and accuracy without requiring skilled techniques, a so-called machine guidance function, which provides an operator with the posture of the work machine and the tip position of the attachment via a display, is sometimes installed in work machines.

[0004] Patent Document 1 proposes a work machine that, in the machine guidance function, displays a line indicating the direction parallel to the work target surface on an overhead image around the vehicle body, and enables the operator to intuitively understand the swing direction required to make the upper swing body directly face the work target surface.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In breaker operations, the hydraulic cylinder driving the front work device can function as a damper to reduce the impact vibrations applied by the breaker to the front work device. However, if breaker operation is performed at the end of the cylinder's stroke, the impact vibrations are transmitted to the work device without being dampened by the cylinder, making the work device, including the hydraulic cylinder, more susceptible to damage. Therefore, in breaker operations, it is necessary to position the work machine in an appropriate position that is less affected by the load, and the operator must check and correct the position of the work machine each time breaker operation is performed. This may reduce work efficiency.

[0007] In the technology described in Patent Document 1, the operator can grasp the alignment of the upper rotating body with a predetermined work surface, such as a slope of the shaping target, but it cannot provide the guidance necessary for breaker work.

[0008] The objective of the present invention is to provide a work machine that can improve the work efficiency of breaker work. [Means for solving the problem]

[0009] The present invention includes multiple means for solving the above problems, but to give one example, a work machine comprising a traveling body, a slewing body rotatably attached to the traveling body, a boom attached to the slewing body, an arm attached to the tip of the boom, a breaker attached to the tip of the arm, a sensor for detecting the posture of the boom, the arm and the breaker, a plurality of cameras for photographing the area around the slewing body, a display, and a controller for generating an overhead view image of the area around the slewing body using images taken by the plurality of cameras and displaying it on the display, wherein the breaker has a reference point set as the basis for posture calculation, and the controller sets a first boundary, which is the boundary of the allowable working range of the breaker, at a position closer to the slewing body than the position reached by the reference point when the arm cylinder that drives the arm reaches the stroke end on the arm dump side, based on the posture state of the boom detected by the sensor, and displays the first boundary on the overhead view image, and also displays a reference image on the overhead view image at a position corresponding to the position of the reference point calculated based on the detected value of the sensor. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a work machine that can improve the work efficiency of breaker work. [Brief explanation of the drawing]

[0011] [Figure 1] An external view of a hydraulic excavator 1, shown as an example of a work machine according to an embodiment of the present invention. [Figure 2] A schematic diagram of the controller 10 and the hardware connected to it. [Figure 3] A diagram showing the breaker's allowable working range 32. [Figure 4] Diagram illustrating the first boundary 28 of the breaker's allowable working range 32. [Figure 5] Diagram illustrating the second boundary 30 of the breaker's allowable working range 32. [Figure 6]A flowchart relating to display processing for a breaker allowable work range 32 executed by a controller 10. [Figure 7] A diagram showing a display example on a display 21 when any one of three display modes (non-display mode, one-side display mode, and constant display mode (both-side display mode)) is selected. [Figure 8] An explanatory diagram defining the swing angle of a revolving structure 3 relative to a traveling body 2 of a hydraulic excavator 1. [Figure 9] An explanatory diagram of an example of a change in arrangement of the breaker allowable work range 32 when a swing operation of the revolving structure 3 is performed while the one-side display mode is selected. [Figure 10] An explanatory diagram regarding presence or absence of notification based on the state of a notification ON / OFF button and the positional relationship between a reference point 5x and the breaker allowable work range 32. [Figure 11] An explanatory diagram for a case where a first work radius R1 is maximized. [Figure 12] An explanatory diagram for a case where a second work radius R2 is maximized. [Figure 13] A schematic configuration diagram of a work support system for the remotely operable hydraulic excavator 1. [Mode for Carrying Out the Invention]

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 is an external view of the hydraulic excavator 1 shown as an example of the work machine according to the embodiment of the present invention. (a) in Figure 1 is a side view of the hydraulic excavator 1, and (b) is a top view of the hydraulic excavator 1.

[0013] The hydraulic excavator 1 includes a traveling body 2, a revolving structure 3 rotatably mounted on the traveling body 2, a front working device 4 that is an articulated work arm mounted on the revolving structure 3, a plurality of cameras 13 mounted on the revolving structure 3 to capture images of the surroundings of the hydraulic excavator 1, a display 21 provided in an operator's cab on the revolving structure 3, and a controller 10 that executes machine guidance, vehicle body control and the like by a processor.

[0014] The front work device 4 includes a boom 6 rotatably attached to the revolving structure 3 via a first pin (boom foot pin) 6c, an arm 7 rotatably attached to the tip end of the boom 6 via a second pin 7c, and a hydraulic breaker (referred to as a breaker) 5 rotatably attached to the tip end of the arm 7 via a third pin 5c.

[0015] The boom 6 is rotated by a pair of hydraulic cylinders (boom cylinders) 6a provided on the left and right of its base end portion, the arm 7 is rotated by a hydraulic cylinder (arm cylinder) 7a spanned between the upper surface of the boom 6 and the base end portion of the arm, and the breaker 5 is rotated by a hydraulic cylinder (attachment cylinder) 5a attached to a link mechanism provided between the breaker 5 and the arm 7.

[0016] An inertial measurement unit (boom IMU) 6b for measuring the angle of the boom 6 is attached to the boom 6, an inertial measurement unit (arm IMU) 7b for measuring the angle of the arm 7 is attached to the arm 7, and an inertial measurement unit (attachment IMU) 5b for measuring the angle of the breaker 5 is attached to the link mechanism. A swing angle sensor 11 that measures the swing angle of the revolving structure 3 relative to the travel body 2, and an inertial measurement unit (not shown) that measures the angle of the revolving structure 3 are attached to the revolving structure 3.

[0017] A chisel 5d is attached to the tip end of the breaker 5, and a piston (not shown) inside the breaker is hydraulically driven to advance and retract along the axial direction of the chisel 5d to repeatedly strike the chisel 5d. The impact energy generated thereby is transmitted to the object to be crushed via the chisel 5d, and the object to be crushed is crushed by the breaker 5.

[0018] A reference point 5x is set on or inside the breaker 5, which serves as the basis for measuring the position and attitude of the breaker 5 during machine guidance. Possible reference points for 5x include, for example, the tip of the chisel 5d, the third pin 5c located at the tip of the arm 7, and the center of gravity of the breaker 5. The position of the reference point 5x is calculated, for example, using coordinate values ​​in three-dimensional space. In this case, it can be calculated from the dimensions of the boom 6, arm 7, and breaker 5, and the inclination angles (attitude angles) of the boom 6, arm 7, and breaker 5 calculated by the IMUs 6b, 7b, and 5b. Alternatively, the inclination angle of the IMU attached to the slewing body 3 may be used to calculate the reference point 5x.

[0019] The running body 2 supports the rotating body 3 so that it can rotate, and has a pair of tracks 2a and 2b positioned on the left and right sides of the vehicle body.

[0020] The cameras 13 are used to generate an overhead view of the area around the hydraulic excavator 1. In this embodiment, one camera 13 is mounted on each side of the rotating body 3, one is mounted behind the rotating body 3, and two cameras 13 are mounted in front of the rotating body 3.

[0021] The controller 10 is a computer having a processor (e.g., a CPU) 17 and memory 16. The processor 17 can execute a program stored in memory 16 to synthesize images taken by multiple cameras 13 to generate an overhead view image of the area around the hydraulic excavator 1, and then display this overhead view image on the display 21.

[0022] As will be explained in detail later, the overhead view image is an image generated by transforming and stitching together images from multiple cameras 13, and is an image of a predetermined area around the hydraulic excavator 1 (for example, an area of ​​270 degrees or more around the hydraulic excavator 1) viewed from above the hydraulic excavator 1. On the overhead view image, a reference image 99 is displayed at a position corresponding to the position of the reference point 5x on the overhead view image, serving as a guide for the position of the reference point 5x. There are no particular limitations on the reference image 99 as long as it is visible on the overhead view image, but for example, an image of the breaker 5 can be used as shown in the examples in Figures 3 and 7 to match the actual machine, or other conspicuous symbols or shapes such as stars or diamonds may be used. The relationship between the reference image 99 and the reference point 5x is such that the reference image 99 is positioned so that the reference point 5x is located within or around the outline of the reference image 99. It is preferable to position an image of the hydraulic excavator 1 viewed from directly above at the center of the overhead view image. The image may be generated from images of the hydraulic excavator 1 captured in real time by camera 13, or from pre-created images of the hydraulic excavator 1 (illustrations, CG, photographs, etc.), or from an appropriate combination of the former and the latter. It is preferable that the overhead image generated by processor 17 be a video (moving image).

[0023] Figure 2 is a schematic diagram of the controller 10 and the hardware connected to it. The controller 10 includes a memory (storage device) 16 that stores various programs and data, and a processor 17 that executes the programs stored in the memory 16. The controller 10 is connected to a boom IMU 6b, an arm IMU 7b, an attachment IMU 5b, a slewing angle sensor 11, an operating device 20 that receives operator input for each hydraulic actuator mounted on the hydraulic excavator 1, multiple cameras 13, a display 21, and an input device 22. The boom IMU 6b receives the tilt angle of the boom 6, the arm IMU 7b receives the tilt angle of the arm 7, the attachment IMU 5b receives the tilt angle of the breaker 5, and the slewing angle of the slewing body 3 relative to the traveling body 2 receives the slewing angle of the slewing body 3 relative to the traveling body 2. Images captured by each camera 13 are input, and signals obtained from the operator's input operations are input from the input device 22. Display commands are output to the display 21.

[0024] The input device 22 outputs a signal to the controller 10 that corresponds to the operator's input operation to the input device 22. For example, in this embodiment, regarding the superimposition of the area on the overhead image on the display 21 of the working posture in which the work device 4 is less likely to be subjected to load during breaker work (referred to as the breaker allowable working range), the operator can input an operation to select one of three modes: (1) a non-display mode in which the breaker allowable working range is not displayed, (2) a constant display mode (both-sided display mode) in which the breaker allowable working range is displayed both in front of and behind the traveling body 2, and (3) a one-sided display mode in which the breaker allowable working range is displayed only on the side closer to the front working device 4 of the traveling body 2. In addition, the operator can input an operation to select ON / OFF a notification that alerts the operator when the reference point of the breaker 5 has moved out of the breaker allowable working range on the overhead image.

[0025] Memory 16 stores the dimensions of the boom 6, arm 7, breaker 5, slewing body 3, and traveling body 2. The posture of the hydraulic excavator 1, including the front working device 4, can be calculated from these dimensions and the inclination angles of each part 6, 7, and 5 of the working device 4 measured by the respective IMUs 6b, 7b, and 5b.

[0026] Figure 3 shows the breaker's allowable working range 32.

[0027] The breaker allowable working range 32 is the range in which the breaker 5 should be kept during breaker operation in order to prevent excessive load from being placed on the front working device 4 during breaker operation. The breaker allowable working range 32 is preferably set for each posture of the boom 6, and is preferably defined on a projection plane onto the horizontal plane (horizontal projection plane), similar to the overhead view image. The breaker allowable working range 32 may be set in front of the traveling body 2, behind it, or both, but in the example in Figure 3, it is located in front of and behind the traveling body 2 (i.e., front and rear of the traveling body 2).

[0028] The boundary of the breaker's allowable working range 32 can be defined by two circles or arcs with different radii centered on the pivot center 3x of the slewing body 3. In this embodiment, these two boundaries are defined by arcs 28 and 30 on the horizontal projection plane. The boundary located relatively further out (further from the pivot center 3x) of the two radial boundaries of the breaker's allowable working range 32 is called the first boundary 28, and the boundary located relatively further in (closer to the pivot center 3x) is called the second boundary 30. The first boundary 28 is located inside the arc drawn by the maximum working radius of the front work device 4, and the second boundary 30 is located outside the arc drawn by the minimum working radius of the front work device 4.

[0029] Figure 4 is an explanatory diagram of the first boundary 28 of the breaker allowable working range 32. The first boundary 28 is set to a position closer to the slewing body 3 than the arc 29 drawn at the position reached by the reference point 5x when the arm cylinder 7a reaches the stroke end on the arm dump side (i.e., when the arm cylinder 7a is in its most retracted state) in the posture of the boom 6 detected by the boom IMU 6b (the posture of the boom 6 at that time). Preferably, the radius of the first boundary 28 (first working radius R1) is the radius defined when the arm cylinder 7a is extended by 5-10% of its movable range from its most retracted state in the posture of the boom 6 at that time. However, from the viewpoint of suppressing damage to hydraulic equipment and ensuring the breaker allowable working range, it is preferable that the radius R1 of the first boundary 28 be the radius defined when the arm cylinder 7a is extended by 100 [mm] from its most retracted state. In this embodiment, the first boundary 28 is calculated based on this.

[0030] Figure 5 is an explanatory diagram of the second boundary 30 of the breaker's allowable working range 32. Working in the arm-vertical position, where the arm 7 is perpendicular to the horizontal plane, is prone to stress on the work machine from the perspective of impact vibration. The second boundary 30 is set to avoid working in the arm-vertical position. The second boundary 30 is set at a position further away from the slewing body 3 than the arc 31 drawn at the position reached by the reference point 5x when the second pin 7c and the third pin 5c are aligned vertically, in the boom 6 position detected by the boom IMU 6b (the boom 6 position at that time), and closer to the slewing body 3 than the first boundary 28. The second working radius R2 is the horizontal distance between the reference point 5x of the breaker 5 and the slewing center 3x in the position where the arm 7 is held perpendicular to the horizontal plane, in the boom 6 position at that time. The position of the second pin 7c (the position of the tip of the boom 6) in the horizontal projection plane also corresponds to the position of the tip of the arm 7 (i.e., the third pin 5c) in the arm-vertical position where the arm 7 is held perpendicular to the horizontal plane. In other words, the second boundary 30 can be set at a position further from the slewing body 3 than the position of the tip of the boom 6 detected by the boom IMU 6b, and closer to the slewing body 3 than the first boundary 28. When the radius of the arc 31 is the second working radius R2, the radius of the second boundary 30 should be set to the second working radius R2 or a larger value.

[0031] Returning to Figure 3, the third boundary 24 and the fourth boundary 25, which are the boundaries of the breaker allowable working range 32 in the rotation direction of the slewing body 3 (circumferential direction of the breaker allowable working range 32), will be explained. In this embodiment, the breaker allowable working range 32 is the area enclosed by the first boundary 28, the second boundary 30, the third boundary 24, and the fourth boundary 25. However, the third boundary 24 and the fourth boundary 25 do not need to be set.

[0032] The third boundary 24 is a straight line passing through the front end of one of the two tracks 2a, 2b on the running body 2 (the right track), the pivot center 3x of the slewing body 3, and the rear end of the other (left track) track 2b. The fourth boundary 25 is a straight line passing through the front end of the other (left track) track 2b on the running body 2, the pivot center 3x of the slewing body 3, and the rear end of one of the two tracks 2a, 2b (the right track). Note that the front end of the tracks 2a, 2b refers to the front side of the rectangle that appears when viewed from directly above. Similarly, the rear end of the tracks 2a, 2b refers to the rear side.

[0033] Incidentally, the breaker 5 is heavier than the bucket, and moving the breaker 5 to the side of the vehicle 2 is likely to cause it to tip over. However, by setting the third boundary 24 and the fourth boundary 25 as described above, and excluding the right and left sides of the vehicle 2 from the allowable working range 32 of the breaker 5, the movement of the breaker 5 to the side of the vehicle 2 is suppressed, thus suppressing the occurrence of tipping over. In addition, if the vehicle 2 is driven with the breaker 5 moved to the side of the vehicle 2, a load is placed on the track on the breaker 5 side, so wear tends to occur unevenly on the track closer to the breaker 5, but by setting the third boundary 24 and the fourth boundary 25 as described above, the occurrence of such problems can also be suppressed.

[0034] Furthermore, while the two boundaries (straight lines) 24 and 25 can both be defined to pass through the front end of one track and the rear end of the other track, it is preferable to define them to pass through the position furthest from the pivot center 3x at either the front or rear end of the track, as shown in the example in Figure 3.

[0035] Figure 6 is a flowchart showing the display process for the breaker's allowable working range 32, which is performed by the controller 10.

[0036] When processing begins, in step S1, the controller 10 synthesizes the video (images) from the five cameras 13 to generate an overhead view (overhead image) of the area around the hydraulic excavator 1 and displays it on the display 21.

[0037] In step S2, the controller 10 determines, based on the input from the input device 22, whether the mode for displaying the breaker's permissible working range 32 on the display 21 (hereinafter sometimes referred to as the "display mode") is set to a non-display mode that does not display the breaker's permissible working range 32 on the display 21. If the non-display mode is set to a non-display mode, the process returns to step S1. In this case, only the overhead view is displayed on the display 21, and the breaker's permissible working range 32 is not displayed (see screen 38 in Figure 7, described later). On the other hand, if any other mode is set to a non-display mode, the process proceeds to step S3.

[0038] Figure 7 shows an example of the display on the display 21 when one of the three display modes (off mode, one-sided display mode, and always-on display mode (two-sided display mode)) is selected.

[0039] The screen 38 located in the lower left of the figure is a display screen in a hidden mode that does not show the breaker allowable working range 32; the screen 34 located at the top of the figure is a display screen in a constantly displayed mode (both-sided display mode) that shows the breaker allowable working range 32 both in front of and behind the vehicle 2; and the screen 36 located in the lower right of the figure is a display screen in a one-sided display mode that shows the breaker allowable working range 32 only on the side closer to the front work device 4 of the vehicle 2.

[0040] Each of the screens 34, 36, and 38 in the figure displays an image of the hydraulic excavator 1 viewed from above and an overhead view of the area around the hydraulic excavator 1. The arrow 33 in the figure indicates the forward direction (forward direction) of the vehicle 2. In the example of Figure 7, the display 21 is a touch panel display that also functions as an input device 22. Mode selection buttons 35, 37, and 39 are located in the lower right corner of each screen 34, 36, and 38, allowing the user to select one of three display modes. As shown in the example, the name of the selected display mode may also be displayed on buttons 35, 37, and 39 on each screen. In the lower left corner of each screen 34, 36, and 38, there is an ON / OFF button for a notification that alerts the user when the reference point 5x of the breaker 5 deviates from the breaker's allowable working range 32 on the overhead view image.

[0041] Returning to the explanation of Figure 6, in step S3, the controller 10 determines, based on the input from the input device 22, whether a one-sided display mode is selected as the display mode for the breaker allowable working range 32 on the display 21, which displays the breaker allowable working range 32 on the side closer to the front work device 4, either in front of or behind the traveling body 2. If the one-sided display mode is selected, the process proceeds to step S4. On the other hand, if the constant display mode (both-sided display mode) is selected, the process proceeds to step S7, where the breaker allowable working range 32 is displayed on both the front and rear sides of the traveling body 2.

[0042] In step S4, in order to determine whether to display the breaker allowable working range 32 in front of or behind the traveling body 2, it is determined whether the swivel angle obtained from the swivel angle sensor 11 is 90 degrees or less or 270 degrees or more. The definition of the swivel angle in this embodiment will be explained using Figure 8.

[0043] Figure 8 is an explanatory diagram illustrating the definition of the slewing angle of the slewing body 3 relative to the traveling body 2 of the hydraulic excavator 1. Arrow 33 indicates the forward direction of the traveling body 2, and the angle at which this forward direction coincides with the front of the slewing body 3 is defined as 0 degrees. The slewing angle of the slewing body 3 is defined to increase from 0 degrees counterclockwise up to 360 degrees. As a result, for example, if the slewing body 3 rotates 90 degrees counterclockwise from the state shown in Figure 8, the angle will be 90 degrees, and similarly, if the slewing body 3 rotates 90 degrees clockwise, the angle will be 270 degrees.

[0044] In step S4, if it is determined that the slewing angle of the slewing body 3 is 90 degrees or less or 270 degrees or more, the front work device 4 is positioned on the front side of the traveling body 2, and the process proceeds to step S5 to display the breaker allowable working range 32 in front of the traveling body 2. On the other hand, if it is determined that the slewing angle is greater than 90 degrees and less than 270 degrees, the front work device 4 is positioned on the rear side of the traveling body 2, and the process proceeds to step S6 to display the breaker allowable working range 32 behind the traveling body 2.

[0045] When displaying the breaker allowable working range 32 on the overhead view in steps S5, 6, and 7, the controller 10 calculates the positions of the first boundary 28 and the second boundary 30 on the overhead view in the posture of the boom 6 at that time, and displays the first boundary 28 and the second boundary 30 at those positions on the overhead view.

[0046] Using Figure 9, an example of how the breaker's allowable working range 32 changes when the slewing body 3 is rotated while the one-sided display mode is selected will be explained. However, in each screen 46-50 of Figure 9, the slewing body 3 is always positioned so that its forward direction faces upward on the screen.

[0047] In Figure 9, the leftmost screen 46 shows a rotation angle of 0 degrees, with the breaker's allowable working range 32 positioned in front of the vehicle 2. From the state of screen 46, rotating the rotating body 3 clockwise (to the right) by 45 degrees results in a rotation angle of 315 degrees, transitioning to screen 47 located to the right of screen 46, where the breaker's allowable working range 32 is positioned in front of the vehicle 2. From the state of screen 47, rotating the rotating body 3 clockwise (to the right) by 60 degrees results in a rotation angle of 255 degrees, transitioning to screen 48 located to the right of screen 47, where the breaker's allowable working range 32 is positioned behind the vehicle 2. From screen 48, rotating the rotating body 3 clockwise (to the right) by 105 degrees results in a rotation angle of 150 degrees, transitioning to screen 49 located to the right of screen 48, where the breaker's allowable working range 32 is positioned behind the vehicle 2. When the rotating body 3 is rotated 90 degrees clockwise (to the right) from screen 49, the rotation angle becomes 60 degrees, and the screen transitions to screen 50, which is located to the right of screen 49, with the breaker's allowable working range 32 positioned in front of the traveling body 2.

[0048] Returning to the explanation of Figure 6, in step S8, the controller 10 determines, based on the input from the input device 22, whether the notification ON / OFF button 42, which sets whether or not to notify the system that the reference point 5x of the breaker 5 has deviated from the breaker's allowable working range 32 on the overhead image, is ON. In this embodiment, the ON / OFF button 42 is provided on the screen of the display 21, and the notification ON / OFF setting may be displayed on the button 42.

[0049] In step S8, if it is determined that the notification ON / OFF button 42 is ON, the process proceeds to step S9. On the other hand, if it is determined that it is OFF, the process returns to step S1, and no notification is sent regardless of the position of the reference point 5x.

[0050] In step S9, the controller 10 calculates the position of the reference point 5x of the breaker 5 based on the outputs of IMUs 5b, 6b, and 7b, and the dimensions of the boom 6, arm 7, and breaker 5. Based on the calculation result, it determines whether the reference point 5x of the breaker 5 is located outside the breaker allowable working range 32. If the reference point 5x is inside the breaker allowable working range 32, the process returns to step S1 and no notification is given. On the other hand, if the reference point 5x is outside the breaker allowable working range 32, the process proceeds to step S10, and the operator is notified that breaker work is being performed outside the breaker allowable working range 32.

[0051] It is preferable to set the system so that no notification is given when the reference point 5x is located on the first working radius R1, but a notification is given when it is located on the second working radius R2. In addition to displaying the information on the display 21, means of notifying (warning) the operator via the notification device include sounding an alarm through the speaker or illuminating a warning light.

[0052] Using Figure 10, we will explain the status of the notification ON / OFF button and whether or not a notification is issued based on the positional relationship between the reference point 5x and the breaker's allowable working range 32.

[0053] If you turn off notifications on screen 40, the second screen from the left in the diagram, you will be taken to screen 41, located to the left of screen 40, and the ON / OFF button in the lower left corner of the screen will display that notifications are OFF, as shown in display 42. If you turn notifications ON again on screen 41, you will be taken back to screen 40, and the ON / OFF button will display that notifications are ON, as shown in display 43. If, in a state like screen 40, you extend the front working device 4 of the hydraulic excavator 1, for example, in an arm dump operation, and the reference point 5x deviates from the breaker's allowable working range 32, you will be taken to screen 45, located to the right of screen 40, and a notification 44 will be displayed indicating that the breaker 5 is outside the breaker's allowable working range 32. If you turn off notifications on screen 45, you will be taken to screen 46, located to the right of screen 45, and a display 42 will be shown indicating that the alarm notification for when the breaker 5 deviates from the allowable working range 32 is OFF, and even if the front working device 4 deviates from the allowable working range 32, a notification 44 like that on screen 45 will not be displayed. If you turn the notification ON again on screen 46, you will be taken back to screen 45, and a notification 44 will be displayed indicating that breaker 5 has deviated from the permissible working range 32.

[0054] <Changes in the breaker's allowable working range 32 according to the posture of boom 6> The position of the breaker's allowable working range 32 on the overhead view may change depending on the orientation of the boom 6. More specifically, the positions of the first boundary 28 and the second boundary 30 may change depending on the orientation of the boom 6.

[0055] First, we will explain the change in the value of the first working radius R1 that defines the first boundary 28 with respect to the boom posture using Figure 11. Figure 11 is an explanatory diagram of the case when the first working radius R1 is at its maximum.

[0056] As shown in this figure, the first working radius R1 is maximized when the height of the first pin (boom foot pin) 6c coincides with the height of the reference point 5x of the breaker 5. However, at this time, the length of the arm cylinder 7a is maintained extended by a predetermined value (e.g., 100 mm) corresponding to 5-10% of the stroke length from the stroke end on the arm dump side.

[0057] When the boom is raised from the position of boom 6 where the first working radius R1 is maximized (referred to as the first reference position), the trajectory of reference point 5x traces a circle centered on the first pin 6c. In other words, when the boom is raised from the position of boom 6 where the first working radius R1 is maximized (first reference position), the first working radius R1 changes to decrease, and the first boundary 28 moves in a direction that brings it closer to the slewing body 3. Similarly, when the boom is lowered from the position of boom 6 where the first working radius R1 is maximized (first reference position), the first working radius R1 changes to decrease, and the first boundary 28 moves in a direction that brings it closer to the slewing body 3.

[0058] Next, we will explain the change in the value of the second working radius R2 that defines the second boundary 30 with respect to the boom attitude using Figure 12. Figure 12 is an explanatory diagram of the case when the second working radius R2 is at its maximum.

[0059] As shown in this figure, the second working radius R2 is defined by the coordinates of the reference point 5x when the arm 7 is positioned in a vertical position with respect to the horizontal plane, and is maximized when the boom 6 is positioned in a position where the height of the first pin (boom foot pin) 6c and the height of the second pin 7c coincide (referred to as the second reference position). In other words, the second working radius R2 is maximized when the boom 6 is positioned in the second reference position and the arm 7 is positioned vertically so that the second pin 7c and the third pin 5c are aligned vertically.

[0060] When the boom is raised from the position of boom 6 where the second working radius R2 is maximized (second reference position), the trajectory of the second pin 7c traces a circle centered on the first pin 6c. In other words, when the boom is raised from the position of boom 6 where the second working radius R2 is maximized (second reference position), the second working radius R2 changes to decrease, and the second boundary 30 moves in a direction that brings it closer to the slewing body 3. Similarly, when the boom is lowered from the position of boom 6 where the second working radius R2 is maximized (second reference position), the second working radius R2 changes to decrease, and the second boundary 30 moves in a direction that brings it closer to the slewing body 3.

[0061] By changing the positions of the first boundary 28 and the second boundary 30 according to the posture of the boom 6 in this way, the accuracy of the boundary position of the breaker allowable working range 32 can be improved, thereby more appropriately suppressing the load on the hydraulic excavator 1 during breaker operation.

[0062] <Effects> (1) In the above embodiment, the work machine 1 comprises a traveling body 2, a slewing body 3 rotatably attached to the traveling body 2, a boom 6 attached to the slewing body 3, an arm 7 attached to the tip of the boom 6, a breaker 5 attached to the tip of the arm 7, sensors 6b, 7b, 5b for detecting the posture of the boom 6, arm 7, and breaker 5, a plurality of cameras 13 for photographing the area around the slewing body 3, a display 21, and a controller 10 that generates an overhead view image of the area around the slewing body 3 using images taken by the plurality of cameras 13 and displays it on the display 21. In this configuration, the breaker 5 has a reference point 5x set as the basis for attitude calculation, and the controller 10 sets a first boundary 28, which is the boundary of the allowable working range 32 of the breaker 5, at a position closer to the slewing body 3 than the position to which the reference point 5x reaches when the arm cylinder 7a that drives the arm 7 reaches the stroke end on the arm dump side, based on the attitude state of the boom 6 detected by the sensor 6b, and displays the first boundary 28 on the overhead view image, as well as a reference image 99 at a position corresponding to the position of the reference point 5x calculated based on the sensor's detected value on the overhead view image.

[0063] In this configuration, the overhead view displayed on the display 21 shows the boundary 28 of the breaker's allowable working range 32 and a reference image (image of breaker 5) 99 that serves as a guide for the reference point 5x. This makes it easy to perform breaker work so that the reference point 5x (breaker 5) is located within the breaker's allowable working range 32. In other words, the operator can be informed via the display 21 whether the posture of the hydraulic excavator 1 is appropriate for breaker work, thereby improving the work efficiency of breaker work.

[0064] (2) In the work machine described in (1) above, the controller 10 sets a second boundary 30 which is the boundary of the breaker allowable working range 32 at a position further from the slewing body 3 than the position of the tip of the boom 6 detected by the sensor (boom IMU 6b), and closer to the slewing body 3 than the first boundary 28, and displays the first boundary 28, the second boundary 30, and the reference image 99 on the overhead view image.

[0065] In this configuration, the overhead view displayed on the display 21 shows the boundaries 28 and 30 of the breaker's allowable working range 32 and the reference image (image of breaker 5) 99, making it easy to perform breaker work so that the reference point 5x (breaker 5) is located within the breaker's allowable working range 32. In other words, the operator can be informed via the display 21 whether the posture of the hydraulic excavator 1 is appropriate for breaker work, thereby improving the work efficiency of breaker work.

[0066] (3) In the work machine described in (1) above, the first boundary 28 is an arc centered on the pivot center 3x of the slewing body 3, and the controller 10 displays the portion of the first boundary 28 located in front of and behind the traveling body 2 that supports the slewing body 3 in a rotatable manner on the overhead view image. By making the boundary 28 of the breaker's permissible working range 32 an arc in accordance with the movement trajectory of the breaker 5 accompanying the slewing motion of the slewing body 3, the accuracy of the boundary position of the breaker's permissible working range 32 can be improved, so that the load on the hydraulic excavator 1 during breaker operation can be suppressed more appropriately. In addition, by displaying the breaker's permissible working range 32 in front of and behind the traveling body 2 on the overhead view image of the display 21, the breaker 5 is prevented from moving to the side of the traveling body 2 outside the breaker's permissible working range 32, so that the risk of the hydraulic excavator 1 tipping over can be reduced, and uneven wear of the tracks 2a and 2b can be suppressed.

[0067] (4) In the work machine described in (1) or (3) above, the controller 10 sets a third boundary 24 which is a straight line passing through the front end of one of the two tracks 2a, 2b of the traveling body 2, the pivot center 3x of the rotating body 3, and the rear end of the other track 2b of the two tracks 2a, 2b, and is the boundary of the breaker's allowable working range, and a fourth boundary 25 which is a straight line passing through the front end of the other track 2b, the pivot center 3x of the rotating body 3, and the rear end of one of the tracks 2a, and is the boundary of the breaker's allowable working range, and displays a reference image (image of the breaker), the first boundary 28, the third boundary 24, and the fourth boundary 25 on the overhead view image.

[0068] By setting circumferential boundaries 24 and 25 of the breaker's allowable working range 32 in this manner and displaying them on the display 21, the breaker 5 is prevented from moving to the side of the vehicle 2 beyond these boundaries 24 and 25. This reduces the risk of the hydraulic excavator 1 tipping over and also prevents uneven wear of the tracks 2a and 2b.

[0069] (5) In any one of the work machines described in (1) to (4) above, the controller 10 outputs a warning via the display 21 (notification device) when the reference point 5x is located outside the breaker allowable working range 32 on the overhead view image (a notification indicating that the breaker 5 has deviated from the breaker allowable working range 32).

[0070] By outputting a warning (notification) in this manner, the operator can quickly recognize that the breaker 5 has deviated from the breaker's permissible working range 32, thereby reducing the time during which the breaker 5 deviates from the breaker's permissible working range 32.

[0071] Furthermore, boundaries may be set by offsetting a predetermined distance inside the allowable working range 32 from each boundary 28, 30, 24, and 25 of the breaker allowable working range 32, and the system may be configured to output a warning when the work deviates from these boundaries. Alternatively, the warning may be changed according to the distance of the reference point 5x from each boundary 28, 30, 24, and 25 of the breaker allowable working range 32.

[0072] (6) In any one of the work machines described in (1)-(5) above, the controller 10 switches whether to display the portion of the first boundary 28 that is located in front of the traveling body 2 or the portion that is located behind the traveling body 2, based on the rotation angle of the rotating body 3 relative to the traveling body 2.

[0073] By switching the display position of the first boundary 28 based on the rotation angle of the rotating body 3 in this way, the first boundary 28 can be displayed only at a position close to the front of the rotating body 3 where the breaker 5 is located, thereby suppressing the display of unnecessary first boundaries 28 on the overhead view. This also makes it easier for the operator to check the surroundings.

[0074] (7) In any one of the work machines described in (1)-(6) above, the controller 10 switches the display of the first boundary 28 on the display 21 based on the operator's input.

[0075] This allows the operator to choose whether or not to display the first boundary 28 according to their intentions, thus preventing the first boundary 28 from being displayed on the overhead view against the operator's intentions when the vehicle 2 moves after the breaker work is completed. This also makes it easier for the operator to check their surroundings.

[0076] <Other> Furthermore, after the flow shown in Figure 6 is started, the controller 10 may be configured to determine whether the attachment mounted on the front work device 4 is a breaker 5 or not, and to hide the breaker allowable working range 32 (first boundary 28, second boundary 30) while an attachment other than a breaker 5 (e.g., a bucket) is mounted. Alternatively, the controller 10 may be configured to automatically select the hide mode while an attachment other than a breaker 5 is mounted.

[0077] The sensors used to measure the posture of the front work device 4 are not limited to IMUs 6b, 7b, and 5b, but may also be used, such as sensors that detect the stroke length of each hydraulic cylinder 6a, 7a, and 5a, or tilt angle sensors for the boom 6, arm 7, and breaker 5.

[0078] In the above description, the case where the display 21 is a touch panel display capable of incorporating the functions of the input device 22 was explained, but the display 21 and the input device 22 (e.g., a switch) may be independent.

[0079] By the way, the above embodiment described a system for when an operator is on board and operating the hydraulic excavator 1, but this embodiment is also applicable to a hydraulic excavator 1 that is operated by remote control by an operator. Next, a work support system for a remotely operated hydraulic excavator 1 will be described using Figure 13. Note that the same reference numerals are used for the same parts as in Figure 2.

[0080] The work support system shown in Figure 13 includes a remote control device 56 to which remote operation commands for the hydraulic excavator 1 are input by an operator (remote operator) in a remote control room 53; a controller 15 on the remote control room 53 side capable of processing operation signals and the like input from the remote control device 56; a display 57 that has the same role as the display 21 on the hydraulic excavator 1 side; and a communication processing device 54 that transmits and receives various information necessary for remotely operating the hydraulic excavator 1 to and from the controller 10 on the hydraulic excavator 1 side via a network 55.

[0081] Remote operation by the operator in the remote control room 53 is often performed by displaying the image from the on-board camera 13 of the hydraulic excavator 1 on the display 57 and relying on this image. However, since it is difficult to grasp the sense of depth from the image of the camera 13, when performing breaker work by remote control, it is difficult for the remote operator to determine from the camera image alone whether they are in an appropriate working posture for the breaker work.

[0082] Therefore, by displaying the same overhead view as on the display 21 and the breaker's permissible working range 32 on the display 57 in the remote control room 53, as shown in the configuration in Figure 13, the operator can determine whether the hydraulic excavator 1 is in an appropriate position for breaker work even when operating remotely, and even if it is difficult to grasp the sense of depth, the hydraulic excavator 1 can be made to assume an appropriate position for breaker work.

[0083] Furthermore, the configurations of the controllers 10 and 15 described above, as well as the functions and execution processes of each such configuration, may be partially or entirely implemented in hardware (for example, by designing the logic for executing each function using an integrated circuit). Alternatively, the configurations of the controllers 10 and 15 described above may be implemented as programs (software) that are read and executed by an arithmetic processing unit (e.g., a CPU) to realize the functions of the controllers 10 and 15. Information related to such programs can be stored, for example, in semiconductor memory (flash memory, SSD, etc.), magnetic storage devices (hard disk drives, etc.), and recording media (magnetic disks, optical disks, etc.).

[0084] Furthermore, in the descriptions of each embodiment above, the control lines and information lines shown are those deemed necessary for the description of that embodiment, but this does not necessarily mean that all control lines and information lines related to the product are shown. In reality, it is safe to assume that almost all components are interconnected. [Explanation of Symbols]

[0085] 2…Traction unit, 2a…Track, 2b…Track, 3…Slewing unit, 3x…Slewing center, 4…Front working device, 5…Hydraulic breaker (breaker), 5…Breaker, 5b…Attachment IMU, 5c…Third pin, 5x…Reference point, 6…Boom, 6b…Boom IMU, 6c…First pin (boom foot pin), 7…Arm, 7a…Hydraulic cylinder (arm cylinder), 7b…Arm IMU, 7c…Second pin, 13…Camera, 17…Processor, 21…Display, 24…Third boundary, 25…Fourth boundary, 28…First boundary, 30…Second boundary, 32…Breaker allowable working range, 42…ON / OFF button, 57…Display, 99…Reference image (breaker image)

Claims

1. A work machine comprising: a traveling body; a slewing body rotatably attached to the traveling body; a boom attached to the slewing body; an arm attached to the tip of the boom; a breaker attached to the tip of the arm; a sensor for detecting the posture of the boom, the arm, and the breaker; a plurality of cameras for photographing the area around the slewing body; a display; and a controller for generating an overhead view image of the area around the slewing body using images captured by the plurality of cameras and displaying it on the display, The aforementioned breaker has a reference point set as the basis for attitude calculation. The aforementioned controller, Based on the state of the boom's posture detected by the sensor, a first boundary, which is the boundary of the breaker's allowable working range, is set at a position closer to the pivoting body than the position reached by the reference point when the arm cylinder driving the arm reaches the stroke end on the arm dump side. The first boundary is displayed on the overhead view image, and a reference image is displayed on the overhead view image at a position corresponding to the position of the reference point calculated based on the sensor's detection value. A work machine characterized by the following features.

2. In the work machine according to claim 1, The controller sets a second boundary, which is the boundary of the allowable working range, at a position further from the slewing body than the position of the boom tip detected by the sensor, and closer to the slewing body than the first boundary, and displays the first boundary, the second boundary, and the reference image on the overhead view image. A work machine characterized by the following features.

3. In the work machine according to claim 1, The first boundary is an arc centered on the pivot point of the rotating body, The controller displays the portion of the first boundary located in front of and behind the vehicle on the overhead view image. A work machine characterized by the following features.

4. In the work machine according to claim 1, The aforementioned controller, A third boundary is defined as a straight line passing through the front end of one of the two tracks of the running body, the pivot center of the slewing body, and the rear end of the other track, which serves as the boundary of the allowable working range. A fourth boundary is defined as a straight line passing through the front end of the other track, the pivot center of the slewing body, and the rear end of the one track, which serves as the boundary of the allowable working range. The reference image, the first boundary, the third boundary, and the fourth boundary are displayed on the overhead view image. A work machine characterized by the following features.

5. In the work machine according to claim 1, The aforementioned controller, When the aforementioned reference point is located outside the permitted working range, a warning is output via the notification device. A work machine characterized by the following features.

6. In the work machine according to claim 1, The controller switches whether to display the portion of the first boundary located in front of the vehicle or the portion located behind the vehicle, based on the turning angle of the turning body relative to the vehicle. A work machine characterized by the following features.

7. In the work machine according to claim 1, The controller switches the display of the first boundary on the display based on the operator's input. A work machine characterized by the following features.

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