Construction machine

Abstract

The present invention provides a construction machine comprising: a shut-off lever for restricting an operation of an operation lever device; a camera for image-capturing a periphery of a vehicle body; a monitor for displaying a camera image captured by the camera; a monitor operation device for instructing an enlargement of a display magnification of the camera image; and a control device for controlling the displaying of the monitor in accordance with an operation of the monitor operation device. When the operation of the operation lever device is restricted by the shut-off lever, the control device for controlling the displaying enlarges a camera image displayed on the monitor in accordance with the display magnification instructed by the monitor operation device, and causes the monitor to display the camera image at a pre-determined prescribed display magnification when the restriction of the operation of the operation lever device by the shut-off lever is released, even when enlargement of the display magnification is instructed by the monitor operation device. Thus, oversight of obstacles by the operator is suppressed during driving.

Description

Construction machinery

[0001] The present invention relates to a construction machine such as a hydraulic excavator.

[0002] Some construction machines, such as hydraulic excavators, are equipped with a function that provides the operator with camera images of the area around the machine. Among these types of construction machines, there is one that divides the camera image into multiple areas, zooms in on a desired area while shrinking other areas, and maintains the overall display area of ​​the camera image while zooming in on a desired area (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2018-33015

[0004] However, in the construction machine of Patent Document 1, surrounding obstacles are displayed smaller than necessary outside the enlarged area, and there is a possibility that the operator will not notice the displayed obstacles while operating the construction machine.

[0005] An object of the present invention is to provide a construction machine that can prevent an operator from overlooking an obstacle while driving.

[0006] In order to achieve the above object, the present invention provides a construction machine comprising a vehicle body, a front working implement attached to the vehicle body, an operating lever device for operating the vehicle body or the front working implement, a shut-off lever for limiting operation of the operating lever device, a camera for photographing the area around the vehicle body, a monitor for displaying camera images photographed by the camera, a monitor operating device for instructing an increase in the display magnification of the camera image displayed on the monitor, and a control device for controlling the display on the monitor in accordance with operation of the monitor operating device, wherein when operation of the operating lever device is limited by the shut-off lever, the control device for controlling the display enlarges the camera image displayed on the monitor in accordance with the display magnification instructed by the monitor operating device, and even when an increase in the display magnification has been instructed by the monitor operating device, causes the camera image to be displayed on the monitor at a predetermined display magnification when the limit on operation of the operating lever device by the shut-off lever is released.

[0007] According to the present invention, it is possible to prevent the operator from overlooking obstacles while driving.

[0008] FIG. 1 is a side view showing the appearance of a hydraulic excavator, which is an example of a construction machine according to a first embodiment of the present invention. FIG. 2 is a schematic view showing the interior of the driver's cab of the hydraulic excavator of FIG. 1. FIG. 3 is a schematic view showing the entire control system for the construction machine according to the first embodiment of the present invention. FIG. 4 is a block diagram showing a schematic representation of the functions of a control device for the construction machine according to the first embodiment of the present invention. FIG. 5 is an example of operation of a touch panel of a monitor provided in the construction machine according to the first embodiment of the present invention. FIG. 6 is an example of operation of a touch panel of a monitor provided in the construction machine according to the first embodiment of the present invention. FIG. 7 is a diagram showing an example of a display pattern of a camera image displayed on a monitor in the construction machine according to the first embodiment of the present invention. FIG. 8 is a diagram showing another example of a display pattern of a camera image displayed on a monitor in the construction machine according to the first embodiment of the present invention. FIG. 9 is a diagram showing an example of setting a setting display area. FIG. 10 is a flowchart showing a monitor display control procedure by the control device provided in the construction machine according to the first embodiment of the present invention. FIG. 11 is an explanatory diagram showing how the display of the camera image on the monitor is enlarged or reduced in response to a zoom operation in the first embodiment of the present invention. FIG. 12 is an explanatory diagram showing how the display of the camera image on the monitor is enlarged or reduced in response to a zoom operation in the first embodiment of the present invention. 10 is a flowchart showing the monitor display control procedure by a control device provided in a construction machine according to a second embodiment of the present invention. FIG. 11 is a block diagram schematically showing the functions of a control device of a construction machine according to a third embodiment of the present invention. FIG. 12 is a flowchart showing the monitor display control procedure by a control device provided in a construction machine according to a third embodiment of the present invention. FIG. 13 is a diagram showing an example of a camera image in a set display area that is forcibly displayed when an object is detected in the third embodiment of the present invention. FIG. 14 is a block diagram schematically showing the functions of a control device of a construction machine according to a fourth embodiment of the present invention. FIG. 15 is a flowchart showing the monitor display control procedure by a control device provided in a construction machine according to a fourth embodiment of the present invention. FIG. 16 is a diagram showing an example of a camera image in a set display area that is forcibly displayed when the output of an acceleration sensor or its rate of change exceeds a predetermined value in the fourth embodiment of the present invention.13 is a flowchart showing a monitor display control procedure performed by a control device provided in a construction machine according to a fifth embodiment of the present invention.

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

[0010] 1 is a side view showing the appearance of a hydraulic excavator, which is an example of a construction machine according to a first embodiment of the present invention. The right side in FIG. 1 is the front of a revolving body 1d.

[0011] The hydraulic excavator 1 includes a vehicle body 1B and an articulated front working unit 1A attached to the vehicle body 1B. The front working unit 1A has a boom 1a, an arm 1b, and a bucket 1c, each of which rotates in a vertical plane. The vehicle body 1B includes a running unit 1e and a rotating unit 1d that is rotatably mounted on the running unit 1e. The rotating unit 1d is equipped with a driver's cab 1f. The base end of the boom 1a of the front working unit 1A is connected to the front of the rotating unit 1d, the arm 1b is connected to the tip of the boom 1a, and the bucket 1c is connected to the tip of the arm 1b. The boom 1a, arm 1b, bucket 1c, rotating unit 1d, and running unit 1e are driven by corresponding hydraulic actuators, specifically, a boom cylinder 2a, an arm cylinder 2b, a bucket cylinder 2c, a swing motor 3d ( FIG. 3 ), and left and right traveling motors 3e, 3f, respectively.

[0012] The rotating body 1d of the hydraulic excavator 1 is provided with an acceleration sensor 8d that outputs the ground angle (angle with respect to the horizontal plane) of the rotating body 1d. An example of the acceleration sensor 8d is an IMU (Inertial Measurement Unit). The boom 1a, arm 1b, and bucket 1c (strictly speaking, the bucket link) are provided with angle sensors 8a-8c that detect the rotation angles of the boom 1a, arm 1b, and bucket 1c, respectively. In this embodiment, IMUs that measure the ground angles of the corresponding members are used as the angle sensors 8a-8c, but it is also possible to use goniometers that measure the relative angles between two members.

[0013] The revolving unit 1d is also equipped with GNSS antennas 9a and 9b for acquiring the current position of the hydraulic excavator 1, and multiple cameras 10a, 10b, and 10c for capturing images of the area around the vehicle body 1B. The camera 10a captures the left side of the revolving unit 1d, the camera 10b captures the rear of the revolving unit 1d, and the camera 10c captures the right side of the revolving unit 1d. Furthermore, the hydraulic excavator 1 may be equipped with a light detection and ranging (LiDAR) 10D as an object detection device for detecting objects around the vehicle body 1B. The LiDAR 10D emits multiple laser beams with optical axis angles shifted in the left-right direction (yaw direction) and the up-down direction (pitch direction), and measures the distance to the irradiation point of each laser beam from the time it takes for each laser beam to reflect off an object and become incident thereon. When the LiDAR 10D is installed, the output of the LiDAR 10D provides position data of each irradiation point (point cloud) based on the position of the LiDAR 10D as measurement data, providing three-dimensional measurement data (point cloud data) of the terrain (shape of the ground surface), and enabling the detection of obstacles such as humans and other construction machinery. However, it is also possible to process the images captured by the cameras 10a-10c and detect obstacles through image recognition, and the cameras 10a-10c can also be configured to function as object detection devices.

[0014] In addition, although not shown in Fig. 1, the rotating body 1d is equipped with an engine 4 as a prime mover, a hydraulic pump 5 driven by the engine 4, and a valve 6 that controls the flow of pressurized oil from the hydraulic pump 5 to hydraulic actuators (such as the boom cylinder 2a), as shown in Fig. 3, which will be described later. The valve 6 is controlled in response to the operation of operating lever devices 7a-7d (Fig. 2) provided in the operator's cab 1f, which controls the supply direction and supply flow rate of pressurized oil from the hydraulic pump 5 to each hydraulic actuator, thereby operating each actuator. An electric motor may be used as the prime mover instead of the engine 4.

[0015] -Driver's Cabin- Figure 2 is a schematic diagram showing the interior of the driver's cab 1f. The driver's cab 1f is equipped with control lever devices 7a-7d for operating the vehicle body or front work equipment, a shutoff lever 18 for limiting the operation of the control lever devices 7a-7d, and a monitor 12 for displaying camera images captured by cameras 10a-10c. For example, operating the control lever device 7a on the left side of the driver's seat forward or backward causes the revolving unit 1d to rotate left or right, and operating it left or right causes the arm 1b to rotate forward or backward. Operating the control lever device 7b on the right side of the driver's seat forward or backward causes the boom 1a to rotate up or down, and operating it left or right causes the bucket 1c to rotate. Furthermore, the monitor 12 of this embodiment is equipped with a touch panel 11 as a monitor operating device for instructing the magnification of the camera images displayed on the monitor 12 to be enlarged.

[0016] -Control System- Figure 3 is a schematic diagram showing the overall control system for a construction machine according to the first embodiment of the present invention. A control device 200 that controls each of the on-board devices is mounted on the rotating body 1d of the hydraulic excavator 1. The control device 200 is configured to include a main C / U 50 that controls the actuators, etc., a GNS C / U 40 that processes information acquired by the GNSS antennas 9a and 9b, and a notification C / U 60 that controls various notifications to the operator.

[0017] Signals are input to the main C / U 50 from the control lever devices 7a-7d, angle sensors 8a-8c, cameras 10a-10c, LiDAR 10D, acceleration sensor 8d, key cylinder 14, shutoff lever 18, and the like. The main C / U 50 controls the engine 4, hydraulic pump 5, and valve 6 in response to these input signals, and controls hydraulic actuators such as the boom cylinder 2a to drive the hydraulic excavator 1. The key cylinder 14 is an operating device that issues commands to start and stop the engine 4 and is installed in the operator's cab 1f. As described above, the shutoff lever 18 is an operating device that limits the operation of the control lever devices 7a-7d. It is configured to hydraulically limit the operation of the hydraulic actuators via the control lever devices 7a-7d by cutting off the pilot pressure that drives the valve 6, and also to electrically limit the operation of the hydraulic actuators via the control lever devices 7a-7d by prohibiting the main C / U 50 from outputting a command signal to the valve 6 (strictly speaking, the solenoid valve that controls the pilot pressure to the valve 6) depending on the position of the shutoff lever 18. In either configuration, the position of the shutoff lever 18 is detected by a potentiometer (not shown) or the like and input to the main C / U 50 .

[0018] The notification C / U 60 has the function of excavating data between the main C / U 50 and displaying the operating status of the hydraulic excavator 1, menu screens, camera images captured by the cameras 10a-10c, etc. on the monitor 12 in response to operation of the touch panel 11.

[0019] The notification C / U 60, together with the main C / U 50, constitutes the display control device 100 that controls the display on the monitor 12 in response to operations on the touch panel 11, and plays the role of a visibility assistance system. In this embodiment, a configuration is exemplified in which the functions of the control device 200 as the display control device 100 are shared between the main C / U 50 and the notification C / U 60, but the functions of the display control device 100 may be provided in a single C / U (Control Unit).

[0020] -Controller- The controller 200 generates display signals based on signals from the touch panel 11 and the cameras 10a to 10c, and outputs the generated display signals to the monitor 12 to control the display on the monitor 12.

[0021] The control device 200, which controls the display on the monitor 12, has the function of enlarging or reducing the camera image displayed on the monitor 12 relative to a preset display area (described later) in accordance with the display magnification indicated by the touch panel 11. However, enlarging or reducing the camera image is performed on the condition that the operation of the operating lever devices 7a-7d by the shutoff lever 18 is restricted (disabled). In other words, enlarging or reducing the camera image is permitted only when the operation of the operating lever devices 7a-7d is restricted by the shutoff lever 18.

[0022] Specifically, the control device 200 stores a preset set display area for the camera image so that a predetermined area around the vehicle body 1B is displayed on the monitor 12, and when the operation of the control lever devices 7a-7d is restricted by the shut-off lever 18, the control device 200 enlarges the camera image displayed on the monitor 12 according to the display magnification instructed by the touch panel 11. The same applies when reducing the image after enlarging it. Conversely, when the restriction on the operation of the control lever devices 7a-7d by the shut-off lever 18 is released, the control device 200 displays the camera image on the monitor 12 at the set magnification (a predetermined display magnification) regardless of the current display area and display magnification of the camera image, that is, even when an instruction to increase the display magnification is issued by the touch panel 11.

[0023] In other words, the set display area is displayed even if the current display area of ​​the camera image is shifted from the set display area or the display magnification has been changed from the set magnification. The set magnification is the display magnification of the set display area. The display of this set display area is a forced process, and when the set display area is forcibly displayed, the display area and display magnification that were displayed as the camera image until just before are not compared with the set display area. If the set display area is already displayed when the shut-off lever 18 is switched to the release position, even if the display of the camera image is forcibly switched to the set display area, the display of the camera image will not change as a result.

[0024] In this embodiment, the control device 200 enlarges or reduces the camera image in response to a pinch operation (pinch out operation / pinch in operation) performed on the touch panel 11. Furthermore, in this embodiment, a plurality of display patterns for the camera image are prepared as options, and the control device 200 selects a display pattern from the options in response to an operation signal input from the touch panel 11, and displays the camera image on the monitor 12 in the selected display pattern.

[0025] FIG. 4 is a block diagram schematically illustrating the functions of the control device 200. As shown in FIG. 4, the control device 200 includes an operation content determination unit 101, a display pattern setting unit 102, a display pattern storage unit 103, a display image creation unit 104, a set display area storage unit 105, and an operation restriction status determination unit 106 in order to perform the above-described display control. These may be realized by hardware elements such as circuits, or by software elements such as programs. For example, the operation content determination unit 101, the display pattern setting unit 102, the display image creation unit 104, and the operation restriction status determination unit 106 are functions executed by a computing device (e.g., a CPU) of the control device 200, and the display pattern storage unit 103 and the set display area storage unit 105 are configured by a storage device (e.g., a HDD) included in or connected to the control device 200. Each function will be described below.

[0026] [Operation restriction state determination unit] The operation restriction state determination unit 106 determines, for example, based on the output of the potentiometer of the shutoff lever 18, whether the position of the shutoff lever 18 is a restriction position that restricts (disables) the operation of the operating lever devices 7a-7d, or a release position that allows the operation of the operating lever devices 7a-7d.

[0027] [Operation Content Determination Unit] The operation content determination unit 101 determines the operation content based on an operation signal input from the touch panel 11. The operation content determination unit 101 determines the operation content based on the position on the screen of the touch panel 11 touched by the operator, the number of fingers touching, the movement of the touching fingers, etc. For example, a pinch-out operation ( FIG. 5A ) or a pinch-in operation ( FIG. 5B ) is recognized as the movement of two fingers touching the screen widening or narrowing the distance between them, and the screen display is enlarged or reduced around the midpoint between the positions where the two fingers touched.

[0028] [Display Pattern Setting Unit] The display pattern setting unit 102 sets a display pattern specified on the touch panel 11 based on the operation content determined by the operation content determination unit 101. At least one display pattern (a plurality of display patterns in this embodiment) is stored in advance in the display pattern storage unit 103 for, for example, the display format of the camera image displayed on the monitor 12. The display pattern setting unit 102 reads and sets a display pattern corresponding to the operation content determined by the operation content determination unit 101 from the display pattern storage unit 103. Examples of display patterns of the camera image displayed on the monitor 12 are shown in Figures 6A and 6B.

[0029] The camera video 201 according to the first display pattern illustrated in FIG. 6A is a real-time bird's-eye view image of the hydraulic excavator 1 generated by combining images captured by the cameras 10a-10c. Specifically, the camera video 201 is a projected display of an bird's-eye view image of the surroundings of the hydraulic excavator 1 generated by combining images captured by the cameras 10a, 10b, and 10c around a hydraulic excavator icon 201d. In an area 201a to the left of the hydraulic excavator icon 201d in the camera video 201, the image captured by the camera 10a is converted into a bird's-eye view image and displayed. Similarly, in an area 201b behind the hydraulic excavator icon 201d and an area 201c to the right of the hydraulic excavator icon 201d, the images captured by the cameras 10b and 10c are converted into bird's-eye views and displayed, respectively.

[0030] The camera image 202 according to the second display pattern illustrated in FIG. 6B is obtained by displaying cropped images captured by cameras 10a and 10b side by side in adjacent areas 202a and 202b. Images captured by different cameras are displayed in areas 202a and 202b, but different areas of an image captured by the same camera can also be displayed side by side in areas 202a and 202b. While FIG. 6B illustrates an example in which areas 202a and 202b displaying two camera images are arranged horizontally, areas 202a and 202b may also be arranged vertically. The camera images displayed in areas 202a and 202b can be switched freely, and each area 202a and 202b can display an image captured by one selected from cameras 10a-10c. Alternatively, a screen configuration in which two camera images are displayed side by side can be adopted, or a screen configuration in which only one image selected from cameras 10a-10c is displayed enlarged instead of displaying multiple camera images side by side can be adopted.

[0031] [Set Display Area Storage Unit] In FIG. 4 , the set display area storage unit 105 stores a set display area that is preset for the camera image displayed on the monitor 12 so that a predetermined area around the vehicle body 1B is displayed on the monitor 12. The set display area is a recommended area for the surrounding area to be displayed on the camera image on the monitor 12 while the hydraulic excavator 1 is operating. For example, an initial value for the set display area is set when the hydraulic excavator 1 is shipped, and the setting can be changed thereafter as needed. The set display area may be an area of ​​a specific size or an area having a range defined by upper and lower limits. The predetermined area around the vehicle body 1B related to the set display area is an area where attention should be paid to interference between an obstacle and the vehicle body 1B. In this embodiment, since the rear end of the revolving unit 1d is in the blind spot of the operator in the cab 1f and is the portion of the revolving unit 1d that describes the maximum turning trajectory, the predetermined area is an area corresponding to the turning radius of the rear end of the revolving unit 1d. That is, in this embodiment, the camera image of the set display area displayed on the monitor 12 shows a surrounding area that is equal to or larger than the turning radius at the rear end of the revolving unit 1d. When multiple display patterns are prepared, the set display area storage unit 105 stores a display magnification (set magnification) that is individually set for each display pattern for displaying the set display area, so that the set display area is displayed on the monitor 12 in each of the multiple display patterns.

[0032] The area corresponding to the turning radius of the rear end of the rotating unit 1d is the narrowest area set as the set display area, and the set display area can be set wider than this. However, if the area is wider than necessary, obstacles displayed on the screen will be small and difficult to see on the monitor 12, so it is necessary to ensure that the obstacles displayed on the monitor 12 do not become excessively small.

[0033] FIG. 7 is a diagram showing an example of the setting of the set display area. The smaller area 204a shown by the dotted line in FIG. 7 is an example of the boundary of the area around the vehicle body that is desired to be shown to the operator on the monitor 12 as a visibility assistance system while the hydraulic excavator 1 is operating. In the example of FIG. 1, the area 204a is set to a value that covers the maximum turning radius of the hydraulic excavator 1. An example of the width of the set display area is area 204a. The larger area 204b shown by the dotted line in FIG. 7 is an example of a boundary that defines the wide-area limit of the area set as the set display area. If an area wider than this area 204b is displayed, obstacles displayed in the camera image 201 will be smaller than allowable, and the visibility of the obstacles will be excessively reduced. The set display area should not be wider than this area 204b. While FIG. 7 illustrates the camera image 201, which is a composite overhead image, the same concept applies to the camera image 202 ( FIG. 6B ), which displays images from individual cameras.

[0034] [Display Image Creation Unit] In FIG. 4, the display image creation unit 104 generates a display image of the display pattern set by the display pattern setting unit 102 from image data input in real time from the cameras 10a-10c based on an operation signal input from the touch panel 11, and outputs the generated image to the monitor 12. Furthermore, the display image creation unit 104 appropriately outputs information such as meters required for driving, maps, menu screens, and setting screens to the monitor 12 based on the operation signal input from the touch panel 11. Furthermore, if the operation content determination unit 101 determines that a pinch operation has been performed on the control lever devices 7a-7d using the shutoff lever 18 based on the determination result of the operation restriction state determination unit 106, the display image creation unit 104 enlarges or reduces the camera image in accordance with the operation. However, if the restriction on the operation of the control lever devices 7a-7d using the shutoff lever 18 is released, the display image creation unit 104 sets the display magnification of the camera image to the set magnification regardless of the current zoom ratio of the camera image and displays the camera image in the set display area on the monitor 12.

[0035] For example, if the operator interrupts operation of the hydraulic excavator 1 to take a break or the like, when resuming operation of the hydraulic excavator 1, the operator can quickly check the situation around the vehicle body 1B by enlarging the camera image before switching the shutoff lever 18 to the release position. Then, when the operator switches the shutoff lever 18 to the release position and starts operating the hydraulic excavator 1, the camera image is automatically switched to a state showing the set display area, without the operator having to adjust the enlargement ratio of the camera image.

[0036] -Display Control- Fig. 8 is a flowchart showing the display control procedure for the monitor 12 by the control device 200. The control device 200 periodically (for example, at short intervals of about 0.1 seconds) executes the flow of Fig. 8 while power is on.

[0037] When the flow of FIG. 8 starts, the control device 200 sets the display magnification of the camera image to the set display magnification and displays the camera image (camera image at the set magnification) in the set display area on the monitor 12 (step S101), and the operation limit state determination unit 106 determines whether the shutoff lever 18 is in the restricted position (step S102). If the shutoff lever 18 is in the released position, the control device 200 skips the next process and returns to step S101. If the shutoff lever 18 is in the restricted position, the control device 200 determines with the operation content determination unit 101 whether an operation to enlarge ( FIG. 5A ) or reduce ( FIG. 5B ) the camera image is being performed on the touch panel 11 (step S103). If an operation to enlarge or reduce the camera image is being performed, the control device 200 determines with the operation content determination unit 101 whether the operation is an operation to enlarge the camera image (step S104).

[0038] If it is determined in step S104 that an operation to enlarge the camera image has been performed, the control device 200 causes the display image creation unit 104 to generate an enlarged image corresponding to the operation, outputs it to the monitor 12, enlarges and displays the camera image displayed on the monitor 12 (step S105), and proceeds to step S108. On the other hand, if it is determined in step S104 that an operation to enlarge the camera image has not been performed, that is, that an operation to reduce the camera image has been performed, the control device 200 causes the display image creation unit 104 to generate a reduced image corresponding to the operation, outputs it to the monitor 12, and reduces and displays the camera image displayed on the monitor 12 (step S106), and proceeds to step S108. If an operation to enlarge or reduce the camera image has not been performed, the control device 200 does not enlarge or reduce the camera image (step S107), and proceeds to step S108.

[0039] When the procedure proceeds to step S108, the control device 200 determines whether the position of the shutoff lever 18 is in the release position using the operation restriction state determination unit 106. If the position of the shutoff lever 18 is in the release position, the control device 200 causes the display image creation unit 104 to create and output a camera image (camera image at the set magnification) that shows the set display area regardless of the display magnification or display area of ​​the camera image currently being displayed, and displays it on the monitor 12 (step S109), and the procedure returns to step S101. If the position of the shutoff lever 18 is in the limit position, the control device 200 returns to step S103 from step S108.

[0040] 9A to 9C are explanatory diagrams illustrating how the display of the camera image on the monitor is enlarged or reduced in response to a zoom operation. For example, assume that in step S101 of Fig. 8, the camera image 201A shown in Fig. 9A is displayed on the monitor 12. The camera image 201A is an image at a set magnification that shows a set display area, and the area that is desired to be shown to the operator while operating the hydraulic excavator 1 is displayed at an appropriate size, and if a predicted obstacle is within the display area of ​​the camera image 201A, the obstacle is clearly reflected in the camera image 201A.

[0041] When a zoom-out operation is performed on this camera image 201A, if the shut-off lever 18 is in the limit position, the camera image 201A is zoomed out, and a camera image 201B with a wider area than the camera image 201A is displayed on the monitor 12, as shown in Fig. 9B, for example. Furthermore, when a zoom-in operation is performed on the camera image 201A, if the shut-off lever 18 is in the limit position, the camera image 201A is zoomed in, and a camera image 201C with a narrower area than the camera image 201A is displayed on the monitor 12, as shown in Fig. 9C, for example. Because the camera image 201B is a reduced-scale display of a composite overhead image using images captured by the cameras 10a-10c, a wide range can be confirmed at a glance, but the images captured by the cameras 10a-10c and the hydraulic excavator icon 201d are displayed smaller, and if there is an obstacle around the vehicle body 1B, the obstacle is also displayed smaller in size in the camera image. Unlike camera image 201B, camera image 201C shows a large image of the area near the hydraulic excavator 1, but the display area is missing from the set display area, narrowing the visible range.

[0042] In this embodiment, when the shut-off lever 18 is switched to the release position, regardless of whether the camera image being displayed on the monitor 12 is at the set magnification like camera image 201A or at a lower or higher magnification than the set magnification like camera image 201B or 201C, the camera image 201A at the set magnification is displayed on the monitor 12 in the processing of step S109.

[0043] - Effect - (1) In this embodiment, the control device 200 can enlarge the camera image displayed on the monitor 12 in accordance with the display magnification instructed by the touch panel 11, provided that operation of the control lever devices 7a-7d is restricted by the shut-off lever 18. This allows the operator to arbitrarily adjust the display magnification of the camera image and change the area visible on the monitor 12 according to the purpose, for example by enlarging the image when wanting to check the detailed condition of the area near the hydraulic excavator 1, thereby contributing to improved work efficiency.

[0044] Furthermore, while being able to enlarge the camera image displayed on the monitor 12 is convenient for the operator to enlarge and check the area of ​​interest in detail, it may result in the area displayed by the camera image becoming excessively narrow when the hydraulic excavator 1 is being operated. The original purpose of displaying the camera image is to provide the operator with visual information about the area around the hydraulic excavator 1 while it is being operated, and there is a recommended appropriate range for the area to be displayed. For example, if the camera image remains enlarged when the operator is operating the hydraulic excavator 1, the area displayed on the monitor 12 may be incomplete relative to the appropriate range that should be presented to the operator, and there is a possibility that the operator will not be able to see the current situation around the hydraulic excavator 1.

[0045] In response to this, the control device 200 allows the display magnification of the camera image to be changed on the condition that the operation of the control lever devices 7a-7d is restricted by the shut-off lever 18, and when the operation restriction of the control lever devices 7a-7d by the shut-off lever 18 is released, the camera image is displayed on the monitor 12 at the set magnification regardless of the current display magnification of the camera image. Therefore, the camera image displayed on the monitor 12 while the hydraulic excavator 1 is in operation will automatically have the set magnification.

[0046] As described above, according to this embodiment, the appropriate range is displayed on the monitor 12 while the hydraulic excavator 1 is in operation, thereby preventing the operator from overlooking obstacles. For example, when the operator resumes operation of the hydraulic excavator 1 after a break, he or she can adjust the display magnification of the camera image on the monitor 12 while the excavator is stopped to quickly check various conditions, and further, when the shut-off lever 18 is switched to the release position to start operating the hydraulic excavator 1, the display magnification of the camera image on the monitor 12 automatically becomes the set magnification without the operator having to manually adjust it each time, which prevents the operator from forgetting to adjust the camera image and saves labor by eliminating the operator's need to adjust the camera image.

[0047] If the camera image displayed on the monitor 12 can be reduced in size, it is convenient for quickly checking the overall situation around the hydraulic excavator 1. However, on the other hand, there is a possibility that the area displayed by the camera image during operation of the hydraulic excavator 1 may become excessively wide. If the display area of ​​the camera image is wide beyond the appropriate range, the display of obstacles and the like that should be notified to the operator may become too small and may be overlooked. Even in this case, when the operation restriction on the operating lever devices 7a-7d by the shutoff lever 18 is released, the camera image is displayed on the monitor 12 at the set magnification regardless of the current display magnification of the camera image, and the same effect as in the case of an enlarged display is obtained.

[0048] (2) The multiple display patterns include an overhead image of the hydraulic excavator 1 generated by combining images captured by multiple cameras 10a-10c, and by displaying the set display area using this overhead image, it is possible to make it easier for the operator to understand the positional relationship between obstacles and the hydraulic excavator 1.

[0049] (3) The display area is set so that an area corresponding to the turning radius of the rotating body 1d is displayed. Therefore, obstacles that may interfere with the vehicle body 1B when the vehicle body 1B turns can be displayed on the monitor 12, and interference between the vehicle body 1B and the obstacles can be rationally suppressed.

[0050] (4) In addition, in this embodiment, a plurality of display patterns of the camera image are prepared and the display pattern can be switched as desired, and the display magnification is set individually for each display pattern so that a set display area is displayed on the monitor 12 for each of the plurality of display patterns, and the set display area is displayed on the monitor 12 regardless of the display pattern. Therefore, it is possible to prevent obstacles that the operator should be aware of while driving from not appearing in the camera image or from being difficult to identify depending on the selected display pattern.

[0051] (5) Furthermore, since the touch panel 11 is used as a monitor operation device for operating the monitor 12, the operator can intuitively and easily zoom in or out on the camera image by pinching the touch panel 11.

[0052] Second Embodiment A second embodiment of the present invention will be described. This embodiment differs from the first embodiment in that, when the touch panel 11 remains unoperated for a preset time α [s], the control device 200 causes the monitor 12 to display the camera image at the set magnification and the setting display area, similar to when the shutoff lever 18 is switched to the release position. The term "unoperated state exceeding the set time α" does not mean that the cumulative time during which the touch panel 11 has not been operated exceeds the set time α, but rather that the duration of the unoperated state up to the present exceeds the set time α. The set time α can be, for example, a time from several seconds to a dozen seconds.

[0053] In this embodiment, a set time α is set in advance for determining whether the touch panel 11 is in a no-operation state, with respect to a no-operation duration Tm [s] during which the touch panel 11 remains in a no-operation state. In this embodiment, the display image creation unit 104 determines whether the no-operation duration Tm of the touch panel 11 exceeds the set time α (Tm>α), and when the no-operation duration Tm exceeds the set time α, the display of the camera image is forcibly switched to the set display area, regardless of the display area and display magnification of the currently displayed camera image, even if the shutoff lever 18 is in the restricted position. Of course, even if the no-operation duration Tm is equal to or shorter than the set time α, the display of the camera image is forcibly switched to the set display area when the shutoff lever 18 is switched to the released position, as in the first embodiment.

[0054] -Display Control- Figure 10 is a flowchart showing the monitor display control procedure performed by a control device provided in a construction machine according to a second embodiment of the present invention. Figure 10 corresponds to Figure 8 of the first embodiment, and in Figure 10, processes that are similar to or correspond to those in the first embodiment are given the same numbers as in Figure 8, and descriptions thereof will be omitted as appropriate. The control device 200 repeatedly executes the flow of Figure 10 periodically (for example, at short intervals of about 0.1 seconds) while power is supplied.

[0055] When the flow of Figure 10 is started, the control device 200 executes steps S101 to S108 in the same manner as in the first embodiment, and if a zoom-in or zoom-out operation is performed on the touch panel 11, it zooms in or out on the camera image displayed on the monitor 12, and determines whether the position of the shut-off lever 18 has been switched to the release position.If the shut-off lever 18 has been switched to the release position, the procedure returns to step S101 via step S109.

[0056] In this embodiment, if it is determined that the shutoff lever 18 remains in the limit position, the control device 200 does not proceed to step S109, but instead proceeds from step S108 to step S108a to determine whether the current no-operation duration Tm of the touch panel 11 exceeds the set time α (Tm>α). If the no-operation duration Tm exceeds the set time α, the control device 200 forcibly switches the display of the camera image currently being displayed on the monitor 12 to the set display area (step S109), and returns the process to step S101. If the no-operation duration Tm is equal to or less than the set time α, the control device 200 returns from step S108a to step S103.

[0057] The other configurations and functions of the construction machine of this embodiment are the same as those of the construction machine of the first embodiment.

[0058] Effect: According to this embodiment, when the duration of no operation Tm of the touch panel 11 exceeds the set time α, the camera image displayed on the monitor 12 switches to the setting display area, even if the shutoff lever 18 is in the restricting position. For example, while the operator is operating the monitor 12 with the shutoff lever 18 restricting operation of the control lever devices 7a-7d, the duration of no operation Tm does not exceed the set time α. Therefore, by positioning the shutoff lever 18 in the restricting position, the operator can operate the touch panel 11 without restriction. Thereafter, for example, when the operator has finished operating the touch panel 11 and is waiting, the setting display area is displayed on the camera image when the duration of no operation Tm exceeds the set time α. The same applies when the shutoff lever 18 is switched to the release position to start operating the hydraulic excavator 1. This embodiment also provides the same effect as the first embodiment, and allows zooming in and out of the camera image only while the operator is operating the touch panel 11 with the shutoff lever 18 restricting operation of the control lever devices 7a-7d.

[0059] (Third Embodiment) A third embodiment of the present invention will be described. This embodiment differs from the first embodiment in that, when an object is detected by the object detection device, the control device 200 causes the monitor 12 to display the camera image at the set magnification, as in the case where the shutoff lever 18 is switched to the release position, and causes the monitor 12 to display a set display area. In this embodiment, a configuration will be described in which the cameras 10a-10c also function as object detection devices, but it is of course also possible to use the LiDAR 10D as the object detection device.

[0060] -Control device- Figure 11 is a block diagram showing the functions of a control device for a construction machine according to a third embodiment of the present invention. Figure 11 corresponds to Figure 4 of the first embodiment, and elements in Figure 11 that are the same as or correspond to those in the first embodiment are given the same reference numerals as in Figure 4, and descriptions thereof will be omitted where appropriate.

[0061] 11 , in order to execute the above-described display control, the control device 200 includes an operation content determination unit 101, a display pattern setting unit 102, a display pattern storage unit 103, a display image creation unit 104, a set display area storage unit 105, and an operation restriction state determination unit 106, as well as an object detection unit 107. The object detection unit 107 is a function executed by a calculation unit (e.g., a CPU) of the control device 200.

[0062] In this embodiment, the object detection unit 107 detects objects based on the output of the cameras 10a-10c. In this case, the object can be detected by image processing. The area in which the object is detected can be appropriately set within the captureable area of ​​the cameras 10a-10c, but it is also possible to determine whether an object has been detected in a set display area, for example.

[0063] In this embodiment, the display image creation unit 104 inputs the object detection determination result of the object detection unit 107 based on the images captured by the cameras 10a-10c, and if an object is detected, even if the shutoff lever 18 is in the restricted position, the display magnification of the camera image is set to the set magnification and the camera image in the set display area is forcibly displayed on the monitor 12, regardless of the display area and display magnification of the currently displayed camera image. Therefore, even if the camera image is being enlarged by operating the touch panel 11, if an object is detected, the display of the camera image is forcibly switched to the set display area. Of course, even if no object is detected, if the shutoff lever 18 is switched to the released position, the display of the camera image is forcibly switched to the set display area, as in the first embodiment.

[0064] -Display Control- Figure 12 is a flowchart showing the monitor display control procedure performed by a control device provided in a construction machine according to a third embodiment of the present invention. Figure 12 corresponds to Figure 8 of the first embodiment and Figure 10 of the second embodiment, and in Figure 12, processes that are similar to or correspond to those in the first or second embodiment are given the same numbers as in Figure 8 or Figure 10, and descriptions thereof will be omitted as appropriate. The control device 200 repeatedly executes the flow in Figure 12 periodically (for example, at short intervals of about 0.1 seconds) while power is supplied.

[0065] When the flow of Figure 12 is started, the control device 200 executes steps S101 to S108 in the same manner as in the first and second embodiments, and if a zoom-in or zoom-out operation is performed on the touch panel 11, it zooms in or out on the camera image displayed on the monitor 12, and determines whether the position of the shut-off lever 18 has been switched to the release position.If the shut-off lever 18 has been switched to the release position, the procedure returns to step S101 via step S109.

[0066] In this embodiment, if it is determined that the shut-off lever 18 remains in the limit position, the control device 200 does not proceed to step S109, but instead proceeds from step S108 to step S108b to determine whether an object has been detected by the cameras 10a-10c. If an object has been detected, the control device 200 forcibly switches the display of the camera image currently being displayed on the monitor 12 to the set display area (step S109), and returns the process to step S101. If an object has not been detected, the control device 200 returns the process from step S108b to step S103.

[0067] The other configurations and functions of the construction machine of this embodiment are the same as those of the construction machine of the first or second embodiment.

[0068] Fig. 13 is a diagram showing an example of a camera image in the set display area that is forcibly displayed when an object is detected in this embodiment. The camera image 201A shown in Fig. 13 is an image that shows the set display area as described in Fig. 9A, and in Fig. 13, a detected obstacle 201e is displayed in the area 201a to the left of the hydraulic excavator icon 201d. In Fig. 13, a human is shown as the obstacle 201e, but other obstacles such as construction machinery or structures are also displayed in the same manner when they are detected.

[0069] - Effects - In this embodiment, the same effects as in the first embodiment can be obtained. In addition, when an object is detected, the camera image is switched to a set display area, so that, for example, if an obstacle 201e such as a person or another construction machine approaches the vehicle body 1B while the operation of the hydraulic excavator 1 is interrupted and the camera image is enlarged to check the condition near the vehicle body 1B, the display of the camera image is automatically switched to the set display area, and the obstacle 201e approaching the vehicle body 1B is displayed on the monitor 12. This allows the operator to quickly become aware of the presence of the obstacle 201e around the vehicle body 1B before starting operation of the hydraulic excavator 1.

[0070] This embodiment can be combined with the second embodiment. In this case, zooming in and out of the camera image is permitted on the condition that the operation of the operating lever devices 7a-7d is disabled by the shut-off lever 18, and when the shut-off lever 18 is switched to the release position, when the duration Tm of no operation of the touch panel 11 exceeds the set time α, or when an obstacle 201e is detected, the display magnification of the camera image becomes the set magnification regardless of the display area or display magnification of the camera image currently being displayed, and the camera image in the set display area is displayed on the monitor 12.

[0071] (Fourth Embodiment) A fourth embodiment of the present invention will be described. This embodiment differs from the first embodiment in that, when the output of the acceleration sensor 8d or its rate of change exceeds a predetermined value, the control device 200 causes the monitor 12 to display the camera image at a set magnification and a set display area on the monitor 12. The predetermined value is a threshold value set in advance for detecting a collision between the hydraulic excavator 1 (e.g., the vehicle body 1B) and an obstacle (e.g., another construction machine or falling rocks).

[0072] -Control device- Figure 14 is a block diagram showing the functions of a control device for a construction machine according to a fourth embodiment of the present invention. Figure 14 corresponds to Figure 4 of the first embodiment and Figure 11 of the third embodiment, and elements in Figure 14 that are the same as or correspond to those in the embodiments already explained are given the same reference numerals as in Figures 4 and 11, and explanations thereof will be omitted as appropriate.

[0073] In this embodiment, the display image creation unit 104 inputs the output signal A of the acceleration sensor 8d, and when the output of the acceleration sensor 8d or its rate of change exceeds a predetermined value β, the display magnification of the camera image is set to the set magnification and the camera image in the set display area is forcibly displayed on the monitor 12, regardless of the display area or display magnification of the currently displayed camera image, even if the shut-off lever 18 is in the restricted position. Therefore, even if the camera image is being enlarged by operating the touch panel 11, if an impact is applied to the vehicle body 1B, for example, due to another construction machine colliding with the vehicle body 1B, the display of the camera image is forcibly switched to the set display area, as in the first embodiment. Of course, even if the output of the acceleration sensor 8d or its rate of change does not exceed the predetermined value, when the shut-off lever 18 is switched to the released position, the display of the camera image is forcibly switched to the set display area, as in the first embodiment.

[0074] -Display Control- Figure 15 is a flowchart showing the monitor display control procedure performed by a control device provided in a construction machine according to a fourth embodiment of the present invention. Figure 15 corresponds to Figures 8, 10, and 12 of the previously described embodiments, and processes in Figure 15 that are similar to or correspond to those in the previously described embodiments are given the same numbers as in Figure 8, 10, or 12, and descriptions thereof will be omitted as appropriate. The control device 200 repeatedly executes the flow in Figure 15 periodically (for example, at short intervals of about 0.1 seconds) while power is supplied.

[0075] When the flow of Figure 15 is started, the control device 200 executes steps S101 to S108 in the same manner as in each of the previously described embodiments, and if a zoom-in or zoom-out operation is performed on the touch panel 11, it zooms in or out on the camera image displayed on the monitor 12, and determines whether the position of the shut-off lever 18 has been switched to the release position.If the shut-off lever 18 has been switched to the release position, the procedure returns to step S101 via step S109.

[0076] In this embodiment, if it is determined that the shutoff lever 18 remains in the limit position, the control device 200 does not proceed to step S109, but instead proceeds from step S108 to step S108c to determine whether the output input in real time from the acceleration sensor 8d or its rate of change exceeds a predetermined value. If the output or its rate of change of the acceleration sensor 8d exceeds the predetermined value, the control device 200 forcibly switches the display of the camera image currently being displayed on the monitor 12 to the set display area (step S109) and returns the process to step S101. If the output or its rate of change of the acceleration sensor 8d is equal to or less than the predetermined value, the control device 200 returns from step S108c to step S103.

[0077] The other configurations and functions of the construction machine of this embodiment are the same as those of the construction machines of the above-described embodiments.

[0078] Fig. 16 is a diagram showing an example of a camera image in the setting display area that is forcibly displayed when the output of the acceleration sensor 8d or its rate of change exceeds a predetermined value in this embodiment. The camera image 201A shown in Fig. 16 is an image that reflects the setting display area as described in Fig. 9A, and Fig. 16 shows an obstacle 201f that has collided with the vehicle body 1B in an area 201c to the right of the hydraulic excavator icon 201d. Although Fig. 16 shows a dump truck as an example of the obstacle 201f, obstacles such as other construction machinery or objects (falling rocks, etc.) are also displayed in the same manner when a collision with the hydraulic excavator 1 is detected based on the output of the acceleration sensor 8d.

[0079] - Effects - In this embodiment, the same effects as in the first embodiment can be obtained. In addition, when the output of the acceleration sensor 8d or its rate of change exceeds a predetermined value, the camera image is switched to a set display area. Therefore, for example, if an obstacle 201f such as another construction machine collides with the vehicle body 1B while the operation of the hydraulic excavator 1 is interrupted and the camera image is enlarged to check the condition near the vehicle body 1B, the display of the camera image will automatically switch to the set display area, and the obstacle 201f that collided with the hydraulic excavator 1 will be displayed on the monitor 12. This allows the operator to quickly learn of the obstacle 201f that has collided with the hydraulic excavator 1, the collision position of the obstacle 201f relative to the hydraulic excavator 1, the state of the collision, etc.

[0080] In this embodiment, an example in which a display control function according to the output of the acceleration sensor 8d is added to the first embodiment has been described, but it goes without saying that this embodiment can be combined with at least one of the second embodiment and the third embodiment.

[0081] Fifth Embodiment A fifth embodiment of the present invention will be described. This embodiment differs from the first embodiment in that the control device 200 stores, in addition to the set display area, a wide-area display area that is set wider than the set display area, and when switching the display on the monitor 12 to a camera image in the set display area, the camera image in the wide-area display area is displayed on the monitor 12, and then the display is switched to the camera image in the set display area. As an example, when the area 204a in Figure 7 is set as the set display area, the area 204b in the same figure can be set as the wide-area display area.

[0082] In this embodiment, the wide-area display area is set in advance and stored together with the set display area in set display area storage unit 105. In this embodiment, when shut-off lever 18 is switched to the release position, display image creation unit 104 forcibly switches the display of the camera image to the wide-area display area regardless of the display area or display magnification of the camera image currently being displayed, and after displaying the wide-area display area for a predetermined time (e.g., several seconds), switches the display to the set display area.

[0083] -Display Control- Figure 17 is a flowchart showing the monitor display control procedure performed by a control device provided in a construction machine according to a fifth embodiment of the present invention. Figure 17 corresponds to Figures 8, 10, 12, and 15 of the previously described embodiments, and processes in Figure 17 that are similar to or correspond to those in the previously described embodiments are given the same numbers as in Figure 8, 10, 12, or 15, and descriptions thereof will be omitted as appropriate. The control device 200 repeatedly executes the flow in Figure 17 periodically (for example, at short intervals of about 0.1 seconds) while power is supplied.

[0084] When the flow of FIG. 17 begins, the control device 200 executes steps S101-S108, as in the previously described embodiments. When a zoom operation is performed on the touch panel 11, the control device 200 zooms in or out on the camera image displayed on the monitor 12, and determines whether the shutoff lever 18 has been switched to the release position. If the shutoff lever 18 is in the release position, the control device 200 uses the display image creation unit 104 to create a camera image showing the wide-area display area regardless of the display magnification or display area of ​​the currently displayed camera image, and displays the image on the monitor 12 for a predetermined period of time (step S108f). Then, the control device 200 displays the camera image showing the set display area on the monitor 12 (step S109), and returns the procedure to step S101. For example, after the camera image 201B of FIG. 9B is displayed, the display switches to the camera image 201A of FIG. 9A. If the shutoff lever 18 is in the limit position, the control device 200 returns the procedure from step S108 to step S103.

[0085] The other configurations and functions of the construction machine of this embodiment are the same as those of the construction machines of the above-described embodiments.

[0086] Fig. 16 is a diagram showing an example of a camera image in the setting display area that is forcibly displayed when the output of the acceleration sensor 8d or its rate of change exceeds a predetermined value in this embodiment. The camera image 201A shown in Fig. 16 is an image that reflects the setting display area as described in Fig. 9A, and Fig. 16 shows an obstacle 201f that has collided with the vehicle body 1B in an area 201c to the right of the hydraulic excavator icon 201d. Although Fig. 16 shows a dump truck as an example of the obstacle 201f, obstacles such as other construction machinery or objects (falling rocks, etc.) are also displayed in the same manner when a collision with the hydraulic excavator 1 is detected based on the output of the acceleration sensor 8d.

[0087] -Effects- In this embodiment, the same effects as in Embodiment 1 can be obtained. In addition, because the display of the camera image is switched in stages to the set display area via the wide-area display area, the operator can quickly check the situation around the hydraulic excavator 1 using the camera image in the wide-area display area before the display of the camera image is switched to the set display area.

[0088] Note that, although this embodiment has been described as an example in which gradual switching of the display area is applied to the first embodiment, it goes without saying that it can also be applied to any of the second embodiment, the third embodiment, the fourth embodiment, and an embodiment in which at least two of these are combined.

[0089] (Modifications) The present invention is not limited to the above-described embodiments and may include various modifications. For example, the present invention is not necessarily limited to configurations that include all of the configurations described in the above-described embodiments. For example, it is possible to replace some of the configurations with other configurations. It is also possible to delete some of the configurations of the embodiments or add other configurations.

[0090] For example, in the above embodiment, an example has been described in which the touch panel 11 is used as the monitor operation device for operating the monitor 12, but the monitor operation device may be an operation device that uses physical buttons, dials, switches, etc. Also, while the hydraulic excavator 1 equipped with multiple cameras 10a-10c has been described as an example, the present invention is also applicable to a hydraulic excavator 1 equipped with only one camera. Furthermore, while the hydraulic excavator 1 has been described as an example of a construction machine to which the present invention is applied, the present invention is also applicable to other construction machines such as wheel loaders.

[0091] 1...hydraulic excavator (construction machinery), 1A...front working machine, 1B...vehicle body, 7a-7d...operation lever device, 8d...acceleration sensor, 10a-10c...camera (object detection device), 10D...LiDAR (object detection device), 11...touch panel (monitor operation device), 12...monitor, 18...shut-off lever, 200...control device, 201...camera image (bird's-eye view image), 201A...camera image (setting display area), 201B...camera image (wide-area display area), 201C...camera image (enlarged display), 202...camera image, Tm...non-operation duration, α...setting time

Claims

1. A construction machine comprising: a vehicle body; a front working machine attached to said vehicle body; an operating lever device for operating said vehicle body or said front working machine; a shut-off lever for limiting the operation of said operating lever device; a camera for photographing the area around said vehicle body; a monitor for displaying camera images photographed by said camera; a monitor operating device for instructing an enlargement of a display magnification of the camera image displayed on said monitor; and a control device for controlling the display of said monitor in accordance with the operation of said monitor operating device, wherein the control device for controlling the display enlarges the camera image displayed on said monitor in accordance with the display magnification instructed by said monitor operating device when the operation of said operating lever device is restricted by said shut-off lever, and displays the camera image on said monitor at a predetermined display magnification when the restriction on operation of said operating lever device by said shut-off lever is released even when an enlargement of the display magnification has been instructed by said monitor operating device.

2. A construction machine as described in claim 1, characterized in that the control device causes the camera image to be displayed on the monitor at the specified display magnification when the monitor operation device remains in a non-operated state for a preset period of time.

3. A construction machine as claimed in claim 1, comprising a plurality of cameras, and wherein the control device synthesizes images taken by the plurality of cameras to generate an overhead image of the vehicle body as the camera image.

4. A construction machine as described in claim 3, further comprising an object detection device for detecting objects around the vehicle body, and wherein the control device, when an object is detected by the object detection device, causes the camera image to be displayed on the monitor at the specified display magnification.

5. A construction machine according to claim 4, wherein the camera also functions as the object detection device.

6. A construction machine as claimed in claim 3, further comprising an acceleration sensor provided on the vehicle body, and wherein the control device displays the camera image on the monitor at the predetermined display magnification when the output of the acceleration sensor or its rate of change exceeds a predetermined value.

7. A construction machine as described in claim 1, wherein the control device stores a preset set display area for the camera image so that a specified area around the vehicle body is displayed on the monitor, and a wide-area display area set wider than the set display area, and when switching the display on the monitor to the camera image of the set display area, the camera image of the wide-area display area is displayed on the monitor, and then the control device switches to the camera image of the set display area.

Images