Excavator, control system for excavator, and remote operation system for excavator

Abstract

An excavator (100) comprises a lower traveling body (1), an upper turning body (3) mounted on the lower traveling body (1), an attachment (AT) mounted on the upper turning body (3), and an actuator that moves the attachment (AT). The excavator (100) is configured to control the movement of the actuator in a predetermined work site. The excavator (100) may be configured to expedite or restrain the movement of the actuator in the predetermined work site.

Description

Excavator, excavator control system, and excavator remote control system

[0001] The present disclosure relates to an excavator, a control system for an excavator, and a remote operation system for an excavator.

[0002] BACKGROUND ART Conventionally, there is known an excavator that monitors the surroundings using a camera disposed on an upper rotating body (see Patent Document 1).

[0003] JP 2017-147759 A

[0004] However, with the above-described excavator, there is a risk that detection of an object hidden behind an end attachment such as a bucket may be delayed.

[0005] Therefore, it is desirable to provide a shovel that can more reliably prevent contact between the attachment and objects around the attachment.

[0006] A shovel according to an embodiment of the present disclosure comprises a lower running body, an upper rotating body mounted on the lower running body, an attachment mounted on the upper rotating body, a control device mounted on the upper rotating body, and an actuator that moves the attachment, and the control device is configured to control the movement of the actuator at a specified work site.

[0007] The above-described shovel can more reliably prevent contact between the attachment and objects present around the attachment.

[0008] FIG. 1 is a side view of a shovel according to an embodiment of the present disclosure. FIG. 2 is a top view of a shovel according to an embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of a configuration of a hydraulic system mounted on a shovel. FIG. 4 is a diagram of a part of a hydraulic system related to the operation of an arm cylinder. FIG. 5 is a diagram illustrating an example of a configuration of a discharge amount control function. FIG. 6 is a diagram illustrating an example of the contents of a reference table. FIG. 7 is a flowchart of an example of an operation restriction process. FIG. 8 is a diagram illustrating another example of the contents of a reference table. FIG. 9 is a perspective view of a shovel performing crane work. FIG. 10 is a side view of a shovel performing deep excavation work. FIG. 11 is a diagram illustrating an example of an operation status screen. FIG. 12 is a diagram illustrating another example of an operation status screen. FIG. 13 is a schematic diagram illustrating an example of the configuration of a control system for a shovel.

[0009] First, a shovel 100 as an excavator according to an embodiment of the present disclosure will be described with reference to Figures 1 and 2. Figure 1 is a side view of the shovel 100, and Figure 2 is a top view of the shovel 100.

[0010] In this embodiment, the undercarriage 1 of the excavator 100 includes crawlers 1C as driven bodies. The crawlers 1C are driven by a traveling hydraulic motor 2M mounted on the undercarriage 1. However, the traveling hydraulic motor 2M may be a traveling motor-generator serving as an electric actuator. Specifically, the crawlers 1C include a left crawler 1CL and a right crawler 1CR. The left crawler 1CL is driven by a left traveling hydraulic motor 2ML, and the right crawler 1CR is driven by a right traveling hydraulic motor 2MR. The undercarriage 1 functions as a driven body because it is driven by the crawlers 1C.

[0011] An upper rotating body 3 is rotatably mounted on the lower traveling body 1 via a rotating mechanism 2. The rotating mechanism 2, which serves as a driven body, is driven by a rotating hydraulic motor 2A mounted on the upper rotating body 3. However, the rotating hydraulic motor 2A may also be a rotating motor-generator serving as an electric actuator. The upper rotating body 3 functions as a driven body because it is driven by the rotating mechanism 2.

[0012] A boom 4 serving as a driven body is attached to the upper rotating body 3. An arm 5 serving as a driven body is attached to the tip of the boom 4, and a bucket 6 serving as a driven body and an end attachment is attached to the tip of the arm 5. The end attachment is a member attached to the tip of the arm 5, and may be a breaker, grapple, lifting magnet, or the like. The boom 4, arm 5, and bucket 6 constitute an excavation attachment, which is an example of an attachment AT. The boom 4 is driven by a boom cylinder 7, the arm 5 is driven by an arm cylinder 8, and the bucket 6 is driven by a bucket cylinder 9.

[0013] A boom angle sensor S1 is attached to the boom 4, an arm angle sensor S2 is attached to the arm 5, and a bucket angle sensor S3 is attached to the bucket 6.

[0014] The boom angle sensor S1 detects the rotation angle of the boom 4. In this embodiment, the boom angle sensor S1 is an acceleration sensor, and can detect the boom angle, which is the rotation angle of the boom 4 relative to the upper rotating body 3. For example, the boom angle is at its minimum when the boom 4 is lowered to the lowest position, and increases as the boom 4 is raised.

[0015] The arm angle sensor S2 detects the rotation angle of the arm 5. In this embodiment, the arm angle sensor S2 is an acceleration sensor, and can detect the arm angle, which is the rotation angle of the arm 5 with respect to the boom 4. For example, the arm angle is at its smallest when the arm 5 is fully closed, and increases as the arm 5 opens.

[0016] The bucket angle sensor S3 detects the rotation angle of the bucket 6. In this embodiment, the bucket angle sensor S3 is an acceleration sensor, and can detect the bucket angle, which is the rotation angle of the bucket 6 with respect to the arm 5. For example, the bucket angle is at its minimum when the bucket 6 is fully closed, and increases as the bucket 6 opens.

[0017] The boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 may each be a potentiometer using a variable resistor, a stroke sensor that detects the stroke amount of the corresponding hydraulic cylinder, a rotary encoder that detects the rotation angle around the connecting pin, a gyro sensor, a combination of an acceleration sensor and a gyro sensor, or the like.

[0018] The upper rotating body 3 is provided with a cabin 10 serving as a driver's cab, and is equipped with a power source such as an engine 11. The power source may be a hydrogen engine or an electric motor. The upper rotating body 3 is also equipped with an exterior alarm 45A, an object detection device 70, a positioning device 85, a machine body tilt sensor S4, a rotation angular velocity sensor S5, etc. The interior of the cabin 10 is equipped with an operation device 26, a controller 30, a display device 40, an interior alarm 45B, etc. For convenience, in this specification, the side of the upper rotating body 3 to which the boom 4 is attached is referred to as the front, and the side to which the counterweight is attached is referred to as the rear.

[0019] The controller 30 is an example of a processing circuit, and functions as a control device for controlling the shovel 100. In this embodiment, the controller 30 is configured by a computer including a CPU, RAM, NVRAM, ROM, etc. The controller 30 reads out programs corresponding to each function from the ROM, loads them into the RAM, and causes the CPU to execute the corresponding processing.

[0020] The display device 40 is configured to be able to display image information. In the illustrated example, the display device 40 is an organic EL display, and is configured to be able to present image information to the operator of the shovel 100.

[0021] The exterior alarm 45A is configured to be able to output sound toward the outside of the cabin 10. In the illustrated example, the exterior alarm 45A is an exterior speaker, and is configured to be able to output sound to attract the attention of workers working around the excavator 100.

[0022] The indoor alarm 45B is configured to be able to output sound toward the inside of the cabin 10. In the illustrated example, the indoor alarm 45B is an indoor speaker, and is configured to be able to output sound to attract the attention of the operator operating the excavator 100.

[0023] The object detection device 70 is configured to detect objects present around the excavator 100. Examples of objects include people, animals, vehicles, construction machinery, buildings, holes, etc. The object detection device 70 is, for example, an ultrasonic sensor, a millimeter-wave radar, an imaging device, or an infrared sensor. Examples of the imaging device include a monocular camera, a stereo camera, a LIDAR, or a distance image sensor. In this embodiment, the object detection device 70 includes an attachment camera 70A attached to the attachment AT, a rear camera 70B attached to the rear end of the upper surface of the upper rotating body 3, a front camera 70F attached to the front end of the upper surface of the cabin 10, a left camera 70L attached to the left end of the upper surface of the upper rotating body 3, and a right camera 70R attached to the right end of the upper surface of the upper rotating body 3. In the illustrated example, the attachment camera 70A includes a first camera 70A1 attached to the bucket cylinder 9, a second camera 70A2 attached to the left side of the arm 5, and a third camera 70A3 attached to the right side of the arm 5. Note that the attachment camera 70A may be any one or two of the first camera 70A1 to the third camera 70A3, or may include a camera attached to the rear surface of the arm 5, or may include a camera attached to the ventral surface of the arm 5. Also, the attachment camera 70A may be omitted.

[0024] The object detection device 70 may be configured to be able to detect a predetermined object (e.g., a person) within a predetermined area set around the shovel 100. For example, the object detection device 70 may be configured to be able to distinguish between people and non-human objects when detecting them.

[0025] The positioning device 85 is configured to measure the position of the shovel 100. In this embodiment, the positioning device 85 is a GNSS receiver with an integrated electronic compass, and calculates and outputs the latitude, longitude, and altitude of the shovel 100 based on the received GNSS signal, and also calculates and outputs the orientation of the shovel 100.

[0026] The machine body inclination sensor S4 is configured to detect the inclination of the upper rotating body 3 with respect to a predetermined plane. In this embodiment, the machine body inclination sensor S4 is an acceleration sensor that detects the inclination angle about the longitudinal axis and the lateral axis of the upper rotating body 3 with respect to a horizontal plane. The longitudinal axis and the lateral axis of the upper rotating body 3 are, for example, perpendicular to each other and pass through the shovel center point, which is a point on the rotation axis of the shovel 100.

[0027] The swing angular velocity sensor S5 is configured to detect the swing angular velocity of the upper swing body 3. In this embodiment, the swing angular velocity sensor S5 is a gyro sensor. The swing angular velocity sensor S5 may be a resolver, a rotary encoder, or the like. The swing angular velocity sensor S5 may be configured to output at least one of a swing speed and a swing angle. In this case, at least one of the swing speed and the swing angle may be calculated from the swing angular velocity.

[0028] Hereinafter, any combination of the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine body tilt sensor S4, and turning angular velocity sensor S5 will also be collectively referred to as an attitude sensor.

[0029] Next, a configuration example of a hydraulic system mounted on the shovel 100 will be described with reference to Fig. 3. Fig. 3 is a diagram showing a configuration example of a hydraulic system mounted on the shovel 100. In Fig. 3, a mechanical power transmission system, a hydraulic oil line, a pilot line, and an electrical control system are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively.

[0030] The hydraulic system of the excavator 100 mainly includes an engine 11, a pump regulator 13, a main pump 14, a pilot pump 15, a control valve unit 17, an operating device 26, a discharge pressure sensor 28, an operating sensor 29, a controller 30, and a control valve 60.

[0031] In FIG. 3, the hydraulic system circulates hydraulic oil from a main pump 14 driven by an engine 11 to a hydraulic oil tank via a center bypass line CB or a parallel line PC.

[0032] The engine 11 is a drive source of the excavator 100. In this embodiment, the engine 11 is, for example, a diesel engine that operates to maintain a predetermined rotation speed. An output shaft of the engine 11 is connected to the input shafts of the main pump 14 and the pilot pump 15.

[0033] The main pump 14 is configured to supply hydraulic oil via a hydraulic oil line to the control valve unit 17. In this embodiment, the main pump 14 is a swash plate type variable displacement hydraulic pump.

[0034] The pump regulator 13 is configured to control the discharge rate of the main pump 14. In this embodiment, the pump regulator 13 controls the discharge rate (displacement volume) of the main pump 14 by adjusting the tilt angle of the swash plate of the main pump 14 in response to a control command from the controller 30.

[0035] The pilot pump 15 is configured to supply hydraulic oil to hydraulic control devices including the operating device 26 via a pilot line. In this embodiment, the pilot pump 15 is a fixed displacement hydraulic pump. However, the pilot pump 15 may be omitted. In this case, the function of the pilot pump 15 may be realized by the main pump 14. That is, in addition to the function of supplying hydraulic oil to the control valve unit 17, the main pump 14 may have a function of supplying hydraulic oil to the operating device 26, the proportional valve 31 (see FIG. 4), etc. after reducing the pressure of the hydraulic oil by a throttle or the like.

[0036] The control valve unit 17 is a hydraulic control device that controls the hydraulic system in the excavator 100. In this embodiment, the control valve unit 17 includes control valves 171 to 176. The control valve 175 includes a control valve 175L and a control valve 175R, and the control valve 176 includes a control valve 176L and a control valve 1756. The control valve unit 17 can selectively supply hydraulic oil discharged by the main pump 14 to one or more hydraulic actuators via the control valves 171 to 176. The control valves 171 to 176 control the flow rate of hydraulic oil flowing from the main pump 14 to the hydraulic actuators and the flow rate of hydraulic oil flowing from the hydraulic actuators to a hydraulic oil tank. The hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left traveling hydraulic motor 2ML, a right traveling hydraulic motor 2MR, and a swing hydraulic motor 2A.

[0037] The operating device 26 is a device used by an operator to operate the actuators. The actuators include at least one of a hydraulic actuator and an electric actuator. In this embodiment, the operating device 26 supplies hydraulic oil discharged from the pilot pump 15 to the pilot ports of the corresponding control valves in the control valve unit 17 via pilot lines. The pressure of the hydraulic oil supplied to each pilot port (pilot pressure) is a pressure that corresponds to the direction and amount of operation of a lever or pedal (not shown) of the operating device 26 that corresponds to each hydraulic actuator.

[0038] The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In this embodiment, the discharge pressure sensor 28 outputs the detected value to the controller 30.

[0039] The operation sensor 29 is configured to detect the operation of the operation device 26 by the operator. In this embodiment, the operation sensor 29 is an angle sensor that detects the operation direction and operation amount of the lever or pedal of the operation device 26 corresponding to each actuator in the form of an angle, and outputs the detected value to the controller 30. The operation of the operation device 26 may be detected using a sensor other than an angle sensor.

[0040] The main pump 14 includes a left main pump 14L and a right main pump 14R. The left main pump 14L circulates hydraulic oil to a hydraulic oil tank via a left center bypass line CBL or a left parallel line PCL, and the right main pump 14R circulates hydraulic oil to a hydraulic oil tank via a right center bypass line CBR or a right parallel line PCR.

[0041] The left center bypass line CBL is a hydraulic oil line that passes through control valves 171, 173, 175L, and 176L arranged in the control valve unit 17. The right center bypass line CBR is a hydraulic oil line that passes through control valves 172, 174, 175R, and 176R arranged in the control valve unit 17.

[0042] The control valve 171 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the left traveling hydraulic motor 2ML and to discharge the hydraulic oil discharged by the left traveling hydraulic motor 2ML to the hydraulic oil tank.

[0043] The control valve 172 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the right traveling hydraulic motor 2MR and to discharge the hydraulic oil discharged by the right traveling hydraulic motor 2MR to the hydraulic oil tank.

[0044] The control valve 173 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the swing hydraulic motor 2A and to discharge the hydraulic oil discharged by the swing hydraulic motor 2A to the hydraulic oil tank.

[0045] The control valve 174 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the bucket cylinder 9 and to discharge the hydraulic oil in the bucket cylinder 9 to the hydraulic oil tank.

[0046] Control valve 175L is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by left main pump 14L to boom cylinder 7. Control valve 175R is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by right main pump 14R to boom cylinder 7 and to discharge the hydraulic oil in boom cylinder 7 to the hydraulic oil tank.

[0047] The control valve 176L is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the arm cylinder 8 and to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0048] The control valve 176R is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the arm cylinder 8 and to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0049] Left parallel line PCL is a hydraulic oil line that runs parallel to left center bypass line CBL. Left parallel line PCL can supply hydraulic oil to downstream control valves when the flow of hydraulic oil through left center bypass line CBL is restricted or blocked by any of control valves 171, 173, or 175L. Right parallel line PCR is a hydraulic oil line that runs parallel to right center bypass line CBR. Right parallel line PCR can supply hydraulic oil to downstream control valves when the flow of hydraulic oil through right center bypass line CBR is restricted or blocked by any of control valves 172, 174, or 175R.

[0050] The pump regulator 13 includes a left pump regulator 13L and a right pump regulator 13R. The left pump regulator 13L controls the discharge rate (displacement volume) of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L in response to the discharge pressure of the left main pump 14L. Specifically, for example, the left pump regulator 13L adjusts the swash plate tilt angle of the left main pump 14L in response to an increase in the discharge pressure of the left main pump 14L to reduce the discharge rate (displacement volume). The same applies to the right pump regulator 13R. This is to prevent the absorption power (absorption horsepower) of the main pump 14, which is expressed as the product of the discharge pressure and the discharge rate, from exceeding the output power (output horsepower) of the engine 11.

[0051] The operating device 26 includes a left operating lever 26L, a right operating lever 26R, and a travel lever 26D. The travel lever 26D includes a left traveling lever 26DL and a right traveling lever 26DR.

[0052] The left operating lever 26L is used for swing operation and operation of the arm 5. When the left operating lever 26L is operated in the forward / backward direction, it uses the hydraulic oil discharged by the pilot pump 15 to introduce a control pressure corresponding to the amount of lever operation into the pilot port of the control valve 176. When it is operated in the left / right direction, it uses the hydraulic oil discharged by the pilot pump 15 to introduce a control pressure corresponding to the amount of lever operation into the pilot port of the control valve 173.

[0053] Specifically, when the left operating lever 26L is operated in the arm closing direction, it introduces hydraulic oil into the right pilot port of the control valve 176L and into the left pilot port of the control valve 176R. When the left operating lever 26L is operated in the arm opening direction, it introduces hydraulic oil into the left pilot port of the control valve 176L and into the right pilot port of the control valve 176R. When the left operating lever 26L is operated in the left turning direction, it introduces hydraulic oil into the left pilot port of the control valve 173, and when operated in the right turning direction, it introduces hydraulic oil into the right pilot port of the control valve 173.

[0054] The right operating lever 26R is used to operate the boom 4 and the bucket 6. When the right operating lever 26R is operated in the forward / backward direction, it uses the hydraulic oil discharged by the pilot pump 15 to introduce a control pressure corresponding to the amount of lever operation into the pilot port of the control valve 175. When it is operated in the left / right direction, it uses the hydraulic oil discharged by the pilot pump 15 to introduce a control pressure corresponding to the amount of lever operation into the pilot port of the control valve 174.

[0055] Specifically, when the right operating lever 26R is operated in the boom-lowering direction, it introduces hydraulic oil into the right pilot port of the control valve 175R. When the right operating lever 26R is operated in the boom-raising direction, it introduces hydraulic oil into the right pilot port of the control valve 175L and into the left pilot port of the control valve 175R. When the right operating lever 26R is operated in the bucket-closing direction, it introduces hydraulic oil into the right pilot port of the control valve 174, and when operated in the bucket-opening direction, it introduces hydraulic oil into the left pilot port of the control valve 174.

[0056] The travel lever 26D is used to operate the crawler 1C. Specifically, the left travel lever 26DL is used to operate the left crawler 1CL. The left travel lever 26DL may be configured to operate in conjunction with the left travel pedal. When the left travel lever 26DL is operated in the forward / backward direction, it uses hydraulic oil discharged from the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 171. The right travel lever 26DR is used to operate the right crawler 1CR. The right travel lever 26DR may be configured to operate in conjunction with the right travel pedal. When the right travel lever 26DR is operated in the forward / backward direction, it uses hydraulic oil discharged from the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 172.

[0057] The discharge pressure sensor 28 includes a left discharge pressure sensor 28L and a right discharge pressure sensor 28R. The left discharge pressure sensor 28L detects the discharge pressure of the left main pump 14L and outputs the detected value to the controller 30. The same applies to the right discharge pressure sensor 28R.

[0058] The operation sensor 29 includes operation sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. The operation sensor 29LA detects the forward / backward operation of the left control lever 26L by the operator in the form of an angle and outputs the detected value to the controller 30. The operation includes, for example, the lever operation direction and the lever operation amount (lever operation angle). Similarly, the operation sensor 29LB detects the left / right operation of the left control lever 26L by the operator in the form of an angle and outputs the detected value to the controller 30. The operation sensor 29RA detects the forward / backward operation of the right control lever 26R by the operator in the form of an angle and outputs the detected value to the controller 30. The operation sensor 29RB detects the left / right operation of the right control lever 26R by the operator in the form of an angle and outputs the detected value to the controller 30. The operation sensor 29DL detects the operation of the left travel lever 26DL by the operator in the forward / backward direction in the form of an angle, and outputs the detected value to the controller 30. The operation sensor 29DR detects the operation of the right travel lever 26DR by the operator in the forward / backward direction in the form of an angle, and outputs the detected value to the controller 30.

[0059] The controller 30 receives the output of the operation sensor 29 and outputs a control command to the pump regulator 13 as necessary to change the discharge rate of the main pump 14 .

[0060] Here, a description will be given of negative control using the throttle 18 and the control pressure sensor 19. The throttle 18 includes a left throttle 18L and a right throttle 18R, and the control pressure sensor 19 includes a left control pressure sensor 19L and a right control pressure sensor 19R.

[0061] A left throttle 18L is disposed in the left center bypass line CBL between the hydraulic oil tank and the control valve 176L, which is located most downstream. Therefore, the flow of hydraulic oil discharged from the left main pump 14L is restricted by the left throttle 18L. The left throttle 18L generates a control pressure for controlling the left pump regulator 13L. The left control pressure sensor 19L detects this control pressure and outputs the detected value to the controller 30. The controller 30 controls the discharge rate of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L in accordance with this control pressure. The controller 30 decreases the discharge rate of the left main pump 14L as the control pressure increases, and increases the discharge rate of the left main pump 14L as the control pressure decreases. The discharge rate of the right main pump 14R is controlled in a similar manner.

[0062] Specifically, as shown in FIG. 3 , when the excavator 100 is in a standby state in which none of the hydraulic actuators are operated, the hydraulic oil discharged from the left main pump 14L passes through the left center bypass line CBL and reaches the left throttle 18L. The flow of hydraulic oil discharged from the left main pump 14L increases the control pressure generated upstream of the left throttle 18L. As a result, the controller 30 reduces the discharge rate of the left main pump 14L to the minimum allowable discharge rate, thereby suppressing pressure loss (pumping loss) that occurs when the discharged hydraulic oil passes through the left center bypass line CBL. On the other hand, when one of the hydraulic actuators is operated, the hydraulic oil discharged from the left main pump 14L flows into the hydraulic actuator to be operated via the control valve corresponding to the hydraulic actuator. The flow of hydraulic oil discharged from the left main pump 14L reduces or eliminates the amount of hydraulic oil reaching the left throttle 18L, thereby lowering the control pressure generated upstream of the left throttle 18L. As a result, the controller 30 increases the discharge rate of the left main pump 14L, allowing sufficient hydraulic oil to flow into the hydraulic actuator to be operated, ensuring reliable drive of the hydraulic actuator. The controller 30 also controls the discharge rate of the right main pump 14R in a similar manner.

[0063] With the above-described configuration, the hydraulic system of Fig. 3 can suppress unnecessary energy consumption in the main pump 14 in a standby state. The unnecessary energy consumption includes pumping loss caused in the center bypass line CB by the hydraulic oil discharged from the main pump 14. Furthermore, when operating a hydraulic actuator, the hydraulic system of Fig. 3 can reliably supply a necessary and sufficient amount of hydraulic oil from the main pump 14 to the hydraulic actuator to be operated.

[0064] The control valve 60 is configured to switch between an enabled state and an disabled state of the operating device 26. The enabled state of the operating device 26 is a state in which the operator can operate the operating device 26 to move the associated driven body, and the disabled state of the operating device 26 is a state in which the operator cannot operate the operating device 26 to move the associated driven body.

[0065] In this embodiment, the control valve 60 is a solenoid valve that can switch between a connected state and a cut-off state of the pilot line CD1 that connects the pilot pump 15 and the operating device 26. Specifically, the control valve 60 is configured to switch between a connected state and a cut-off state of the pilot line CD1 in response to a command from the controller 30.

[0066] The control valve 60 may be configured to operate in conjunction with a gate lock lever (not shown). Specifically, the control valve 60 may be configured to cut off the pilot line CD1 when the gate lock lever is pushed down and to open the pilot line CD1 when the gate lock lever is pulled up. However, the control valve 60 may be a solenoid valve separate from the solenoid valve that can switch the pilot line CD1 between the open and closed states in conjunction with the gate lock lever.

[0067] Next, a configuration for the controller 30 to operate the actuators using the machine control function will be described with reference to Fig. 4. Fig. 4 is a diagram of a portion of the hydraulic system. Specifically, Fig. 4 is a diagram of the hydraulic system portion related to the operation of the arm cylinder 8. Note that the following description with reference to Fig. 4 relates to the operation of the arm cylinder 8, but is similarly applicable to the operation of other actuators such as the boom cylinder 7, bucket cylinder 9, swing hydraulic motor 2A, left traveling hydraulic motor 2ML, or right traveling hydraulic motor 2MR.

[0068] 4, the hydraulic system includes a proportional valve 31. The proportional valve 31 includes proportional valves 31AL and 31AR.

[0069] The proportional valve 31 functions as a control valve for machine control. The proportional valve 31 is disposed in a pipe connecting the pilot pump 15 and the pilot port of the corresponding control valve in the control valve unit 17, and is configured to be able to change the flow path area of ​​the pipe. In this embodiment, the proportional valve 31 operates in response to a control command output by the controller 30. Therefore, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17 via the proportional valve 31, regardless of the operation of the operating device 26 by the operator. The controller 30 can then apply the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve.

[0070] With this configuration, the controller 30 can operate the hydraulic actuator corresponding to a specific operating device 26 even when no operation is being performed on that specific operating device 26. Furthermore, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to that specific operating device 26 even when an operation is being performed on that specific operating device 26.

[0071] For example, as shown in FIG. 4 , the left operating lever 26L is used to operate the arm 5. Specifically, the left operating lever 26L uses hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure corresponding to operation in the forward / backward direction to the pilot port of the control valve 176. More specifically, when the left operating lever 26L is operated in the arm closing direction (rearward), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R. Furthermore, when the left operating lever 26L is operated in the arm opening direction (forward), it applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R.

[0072] The operation device 26 is provided with a switch SW1. In this embodiment, the switch SW1 is a push button switch provided at the tip of the left operation lever 26L. The operator can operate the left operation lever 26L while pressing the switch SW1. The switch SW1 may be provided on the right operation lever 26R or at another position within the cabin 10.

[0073] The operation sensor 29LA detects the operation of the left operation lever 26L in the forward and backward directions by the operator, and outputs the detected value to the controller 30.

[0074] The proportional valve 31AL operates in response to a control command (current command) output by the controller 30. It adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL. The proportional valve 31AR operates in response to a control command (current command) output by the controller 30. It adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR. The proportional valve 31AL can adjust the pilot pressure so that the control valves 176L and 176R can be stopped at any valve position. Similarly, the proportional valve 31AR can adjust the pilot pressure so that the control valves 176L and 176R can be stopped at any valve position.

[0075] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL in response to the arm closing operation by the operator. Furthermore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL, regardless of the arm closing operation by the operator. In other words, the controller 30 can close the arm 5 in response to the arm closing operation by the operator or regardless of the arm closing operation by the operator.

[0076] Furthermore, in response to an arm-opening operation by the operator, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR. Furthermore, regardless of an arm-opening operation by the operator, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR. In other words, the controller 30 can open the arm 5 in response to an arm-opening operation by the operator or regardless of an arm-opening operation by the operator.

[0077] Furthermore, with this configuration, even when the operator is performing an arm closing operation, the controller 30 can, as necessary, reduce the pilot pressure acting on the closing-side pilot ports of the control valve 176 (the left pilot port of the control valve 176L and the right pilot port of the control valve 176R) to forcibly stop the closing operation of the arm 5. The same applies to the case where the opening operation of the arm 5 is forcibly stopped when the operator is performing an arm-opening operation.

[0078] Alternatively, even when the operator is performing an arm closing operation, the controller 30 may control the proportional valve 31AR as necessary to increase the pilot pressure acting on the opening-side pilot ports of the control valve 176 (the right pilot port of the control valve 176L and the left pilot port of the control valve 176R) that are located opposite the closing-side pilot port of the control valve 176, and forcibly return the control valve 176 to the neutral position, thereby forcibly stopping the closing operation of the arm 5. The same applies to the case where the opening operation of the arm 5 is forcibly stopped when the operator is performing an arm-opening operation.

[0079] Although explanation with reference to the drawings is omitted, the same applies to the case where the operation of the boom 4 is forcibly stopped when the operator is performing a boom-raising or boom-lowering operation, the case where the operation of the bucket 6 is forcibly stopped when the operator is performing a bucket-closing or bucket-opening operation, and the case where the swing operation of the upper swing body 3 is forcibly stopped when the operator is performing a swing operation. The same also applies to the case where the traveling operation of the lower traveling body 1 is forcibly stopped when the operator is performing a traveling operation.

[0080] Although the description has been given of an electric control lever as the form of the control device 26, a hydraulic control lever may be used instead. In this case, the lever operation amount of the hydraulic control lever may be detected in the form of an angle by an angle sensor and input to the controller 30. Furthermore, a solenoid valve may be disposed between the control device 26 as a hydraulic control lever and the pilot port of each control valve. The solenoid valve is configured to operate in response to an electrical signal from the controller 30. With this configuration, when manual operation is performed using the control device 26 as a hydraulic control lever, the control device 26 can move each control valve by increasing or decreasing the pilot pressure in response to the lever operation amount. Furthermore, each control valve may be configured as an electromagnetic spool valve. In this case, the electromagnetic spool valve operates in response to an electrical signal from the controller 30 corresponding to the lever operation amount of the electric control lever.

[0081] Next, an example of a function of the controller 30 to control the discharge rate of the main pump 14 (hereinafter referred to as the "discharge rate control function") will be described with reference to Fig. 5. Fig. 5 shows an example of the configuration of the controller 30 that realizes the discharge rate control function. In this embodiment, the controller 30 has a power control unit 30A, an energy saving control unit 30B, a minimum value selection unit 30C, a maximum value setting unit 30D, and a current command output unit 30E.

[0082] The power control unit 30A is a control unit that realizes power control, which is one of the functions of controlling the discharge rate of the main pump 14. The power control unit 30A is configured to derive a command value Qd for the discharge rate Q based on the discharge pressure Pd of the main pump 14. The discharge rate Q is, for example, a displacement volume, which is the amount of hydraulic oil discharged by the main pump 14 when the rotary shaft of the main pump 14 makes one rotation. However, the discharge rate Q may also be the amount of hydraulic oil discharged by the main pump 14 per unit time (e.g., one minute). The power control function adjusts the discharge rate of the main pump 14 so that the absorbed power (absorbed horsepower), which is expressed as the product of the discharge rate and the discharge pressure of the main pump 14, is equal to or less than the output power (output horsepower) of the engine 11. In this embodiment, the power control unit 30A obtains the discharge pressure Pd output by the discharge pressure sensor 28. The power control unit 30A then refers to a lookup table to derive a command value Qd corresponding to the obtained discharge pressure Pd. The reference table is a reference table relating to a PQ diagram that holds, in a referable manner, the correspondence relationship between the maximum allowable absorption power (e.g., maximum allowable absorption horsepower) of the main pump 14, the discharge pressure Pd, and the command value Qd, and is stored in advance in a non-volatile storage device. The power control unit 30A can uniquely determine the command value Qd by referring to the reference table using, for example, the preset maximum allowable absorption horsepower of the main pump 14 and the discharge pressure Pd output by the discharge pressure sensor 28 as search keys.

[0083] The energy-saving control unit 30B is a control unit that realizes negative control, which is one of the functions of controlling the discharge rate of the main pump 14, and is configured to derive a discharge rate command value Qn based on the control pressure Pn. In this embodiment, the energy-saving control unit 30B acquires the control pressure Pn output by the control pressure sensor 19. The energy-saving control unit 30B then refers to a lookup table to derive a command value Qn corresponding to the acquired control pressure Pn. The lookup table is a lookup table that holds a correspondence relationship (flow rate control characteristic) between the control pressure Pn and the command value Qn so that it can be referenced, and is stored in advance in a non-volatile storage device.

[0084] The minimum value selection unit 30C is configured to select and output the minimum value from a plurality of input values. In this embodiment, the minimum value selection unit 30C is configured to output the smaller of the command value Qd and the command value Qn as the final command value Qf.

[0085] The command value Qn derived by the energy saving control unit 30B is typically selected by the minimum value selection unit 30C when a relatively low-load operation, such as finishing work, leveling work, or traveling work, is being performed. That is, the command value Qn is selected when a low-load operation characteristic is adopted. On the other hand, the command value Qd derived by the power control unit 30A is typically selected by the minimum value selection unit 30C when a relatively high-load operation, such as excavation work, is being performed. That is, the command value Qd is selected when a high-load operation characteristic is adopted. In this way, the command value Qd selected by the minimum value selection unit 30C determines whether the main pump 14 is controlled based on the low-load operation characteristic or the high-load operation characteristic.

[0086] The maximum value setting unit 30D is configured to output a maximum command value Qmax. The maximum command value Qmax is a command value corresponding to the maximum discharge amount of the main pump 14. In this embodiment, the maximum value setting unit 30D is configured to output the maximum command value Qmax, which is stored in advance in a nonvolatile storage device or the like, to the current command output unit 30E.

[0087] Current command output unit 30E is configured to output a current command to pump regulator 13. In this embodiment, current command output unit 30E outputs a current command I derived based on the final command value Qf output by minimum value selection unit 30C and the maximum command value Qmax output by maximum value setting unit 30D to pump regulator 13. Note that current command output unit 30E may also output the current command I derived based on the final command value Qf to pump regulator 13. In this case, maximum value setting unit 30D may be omitted.

[0088] In this manner, the controller 30 controls the discharge rate of the main pump 14. In the illustrated example, the controller 30 separately controls the discharge rate of the left main pump 14L and the discharge rate of the right main pump 14R. Specifically, the controller 30 derives a current command for the left pump regulator 13L based on the discharge pressure of the left main pump 14L detected by the left discharge pressure sensor 28L and the control pressure, which is the pressure of hydraulic oil in the left center bypass line CBL, detected by the left control pressure sensor 19L. The controller 30 then controls the discharge rate of the left main pump 14L by outputting a current command to the left pump regulator 13L. The controller 30 also derives a current command for the right pump regulator 13R based on the discharge pressure of the right main pump 14R detected by the right discharge pressure sensor 28R and the control pressure, which is the pressure of hydraulic oil in the right center bypass line CBR, detected by the right control pressure sensor 19R. The controller 30 controls the discharge amount of the right main pump 14R by outputting a current command to the right pump regulator 13R.

[0089] Next, an example of the contents of a lookup table referenced by the energy-saving control unit 30B will be described with reference to FIG. 6 . FIG. 6 is a diagram showing an example of the correspondence relationship (flow control characteristics) between the control pressure Pn and the command value Qn, which is an example of the contents of the lookup table. Specifically, FIG. 6 plots the control pressure Pn detected by the control pressure sensor 19 on the horizontal axis and the command value Qn on the vertical axis. A broken line including a sloped line GL indicates the relationship between the command value Qn and the control pressure Pn. The command value Qn corresponds to the target discharge rate of the main pump 14. The controller 30 controls the pump regulator 13 so that the actual discharge rate Q of the main pump 14 becomes the target discharge rate. The lookup table shown in FIG. 6 is used to control the respective discharge rates of the left main pump 14L and the right main pump 14R. When controlling the discharge rate of the left main pump 14L, the horizontal axis of FIG. 6 corresponds to the control pressure detected by the left control pressure sensor 19L, and the vertical axis of FIG. 6 corresponds to the command value for the discharge rate of the left main pump 14L. Similarly, when controlling the discharge rate of the right main pump 14R, the horizontal axis of FIG. 6 corresponds to the control pressure detected by the right control pressure sensor 19R, and the vertical axis of FIG. 6 corresponds to the command value of the discharge rate of the right main pump 14R.

[0090] More specifically, FIG. 6 shows the contents of the lookup table referenced when the left operating lever 26L is operated in the arm-opening direction. In FIG. 6 , a solid line indicates the correspondence relationship (flow control characteristics) between the control pressure Pn and the command value Qn when the left operating lever 26L is operated slightly. For example, a slightly operated lever operation refers to an operation with a lever operation amount of less than 20%, where the lever operation amount when the left operating lever 26L is in the neutral position is 0% and the lever operation amount when the left operating lever 26L is tilted to its fullest extent is 100%. Furthermore, FIG. 6 also shows, with a dashed line, the correspondence relationship (flow control characteristics) between the control pressure Pn and the command value Qn when the left operating lever 26L is operated at a half-lever position. Half-lever operation refers to an operation with a lever operation amount of 20% or more but less than 80%. Similarly, FIG. 6 shows, with a dashed line, the correspondence relationship (flow control characteristics) between the control pressure Pn and the command value Qn when the left operating lever 26L is operated at a full-lever position. Full lever operation means, for example, operation with the lever operated to 80% or more.

[0091] In this embodiment, the energy saving control unit 30B is configured to use the inclined line GL passing through the upper end point A and the lower end point B to derive the command value Qn corresponding to the control pressure Pn.

[0092] The upper end point A defines the upper end of the inclined line GL and is represented by a maximum command value Qmax and a first set pressure Px. The maximum command value Qmax is the upper limit of the command value used in negative control. For example, the set value corresponds to a swash plate tilt angle that is a predetermined angle smaller than the maximum swash plate tilt angle of the main pump 14. The first set pressure Px is a set value that is set regardless of the magnitude of the lever operation amount when the left operating lever 26L is operated in the arm-opening direction. In the example shown in FIG. 6 , the magnitude of the lever operation amount when the left operating lever 26L is operated in the arm-opening direction is the magnitude of the inclination angle (rotation angle) of the left operating lever 26L relative to the left operating lever 26L in the neutral position, and is detected by the operation sensor 29LA as an angle sensor. However, the magnitude of the lever operation amount when the left operating lever 26L is operated in the arm-opening direction may be detected by a device other than an angle sensor, such as a pressure sensor, an acceleration sensor, an angular velocity sensor, a resolver, a voltmeter, or an ammeter.

[0093] The lower end point B defines the lower end of the inclined line GL and is represented by a minimum command value Qmin and a second set pressure Py. The minimum command value Qmin is the lower limit of the command value used in negative control, and is, for example, a set value corresponding to a swash plate tilt angle that is a predetermined angle greater than the minimum swash plate tilt angle of the main pump 14 (e.g., a swash plate tilt angle corresponding to the standby flow rate). The second set pressure Py is a value that is set regardless of the magnitude of the lever operation amount when the left operating lever 26L is operated in the arm opening direction, and corresponds, for example, to the control pressure when hydraulic oil at the standby flow rate passes through the throttle 18.

[0094] In the example shown in FIG. 6, the energy-saving control unit 30B is configured to be able to adjust the correspondence relationship (flow control characteristics) between the control pressure Pn and the command value Qn by changing the position of the upper end point A in the vertical axis direction, i.e., by changing the maximum command value Qmax.

[0095] Specifically, the energy-saving control unit 30B adjusts the correspondence relationship (flow control characteristics) between the control pressure Pn and the command value Qn to be appropriate for the state of the excavator 100 at that time by changing the position of the upper end point A depending on whether fine operation is being performed, half lever operation is being performed, or full lever operation is being performed. In the example shown in FIG. 6 , for convenience of explanation, the energy-saving control unit 30B changes the position of the upper end point A in three stages depending on whether fine operation is being performed, half lever operation is being performed, or full lever operation is being performed. However, the energy-saving control unit 30B may be configured to change the position of the upper end point A in two stages or four or more stages depending on the magnitude of the lever operation amount when the left operating lever 26L is operated in the arm-opening direction, or may be configured to change the position of the upper end point A continuously depending on the magnitude of the lever operation amount when the left operating lever 26L is operated in the arm-opening direction. Alternatively, the energy-saving control unit 30B may be configured not to change the position of the upper end point A even when the magnitude of the lever operation amount changes.

[0096] More specifically, when fine operation is being performed, the energy saving control unit 30B is configured so that the upper end point A becomes the upper end point A1 (the point when the maximum command value Qmax is the set value Qmax1) and the slope line GL becomes the slope line GL1, as shown by the solid line in Figure 6.

[0097] Furthermore, the energy-saving control unit 30B is configured to change the slope GL to a slope GL2 with the upper end point A being an upper end point A2 (the point when the maximum command value Qmax is the set value Qmax2) when the half-lever operation is being performed, as shown by the dashed line in Fig. 6. Furthermore, the energy-saving control unit 30B is configured to change the slope GL to a slope GL3 with the upper end point A being an upper end point A3 (the point when the maximum command value Qmax is the set value Qmax3) when the full-lever operation is being performed, as shown by the dashed line in Fig. 6. Note that the set value Qmax3 may be, for example, a set value corresponding to the maximum swash plate tilt angle of the main pump 14.

[0098] By changing the position of the upper end point A in the vertical axis direction in accordance with the amount of operation of the left operating lever 26L in the arm opening direction in this manner, the energy-saving control unit 30B can suppress or prevent the amount of hydraulic oil flowing into the arm cylinder 8 from becoming unstable during the arm-opening operation. If the amount of hydraulic oil becomes unstable, the operator's body will be shaken back and forth, making it impossible to perform a stable arm-opening operation, further destabilizing the amount of hydraulic oil flowing into the arm cylinder 8. In some cases, the operator may experience hunting, which causes the rotation speed of the engine 11 to become unstable. The energy-saving control unit 30B can suppress or prevent problems such as hunting from occurring. In this way, the energy-saving control unit 30B can improve the operability of the arm 5.

[0099] For example, when the arm opening operation is started in the standby state, the amount of hydraulic oil passing through the throttle 18 decreases when the left operating lever 26L is operated in the arm opening direction. This is because most of the hydraulic oil discharged by the main pump 14 is supplied to the arm cylinder 8. The standby state refers to the state of the excavator 100 when, for example, the engine 11 is running and the operating device 26 is not being operated.

[0100] When the supply of hydraulic oil to the arm cylinder 8 reduces the amount of hydraulic oil passing through the orifice 18, the control pressure Pn (negative control pressure) also decreases, and the command value Qn increases as shown in FIG. 6 . If the gradient line GL were fixed to the gradient line GL3, the command value Qn would increase at a greater rate than if the gradient line GL were fixed to the gradient line GL1, reaching a maximum command value Qmax (set value Qmax3) that is greater than the maximum command value Qmax (set value Qmax1) for the gradient line GL1. Furthermore, the rate of increase in the discharge rate of the main pump 14 relative to an increase in the lever operation amount of the left operating lever 26L would also become excessively large, potentially making it difficult for the operator to perform stable arm-opening operations. This is because the excavator 100 would swing back and forth. This swinging motion could sway the operator seated in the cabin 10 of the excavator 100 back and forth, adversely affecting the operator's operation of the operating device 26.

[0101] In contrast, when the inclined line GL1 is used as the inclined line GL corresponding to the lever operation amount (fine operation) of the left operating lever 26L when starting the arm-opening operation, the upper limit of the command value Qn is limited to the set value Qmax1, which is smaller than the set value Qmax3. Therefore, the rate of increase in the discharge rate of the main pump 14 relative to an increase in the lever operation amount of the left operating lever 26L is kept lower than when the inclined line GL3 is used as the inclined line GL. As a result, the swinging of the excavator 100 in the fore-and-aft direction when the arm-opening operation is started is suppressed, allowing the operator to smoothly open the arm 5.

[0102] Furthermore, as shown in FIG. 6, the upper end point A of the inclined line GL becomes higher as the lever operation amount of the left operating lever 26L increases, so the discharge amount of the main pump 14 is not excessively restricted.

[0103] Specifically, by displacing the upper end point A as described above, the energy saving control unit 30B can prevent the discharge amount Q from becoming small when the arm is opened by full lever operation.

[0104] For example, if the inclination line GL is fixed to the inclination line GL1 used for fine operation when the left operating lever 26L is operated in the arm-opening direction by full lever operation, the upper limit of the command value Qn will be limited to the set value Qmax1, which is smaller than the set value Qmax3. In other words, even though the main pump 14 is in a situation where full lever operation is being performed and the discharge rate Q should be as large as possible, the swash plate tilt angle cannot be increased sufficiently.

[0105] In contrast, when the inclined line GL3 is used as the inclined line GL, the upper end point A is set to the upper end point A3. In this case, the energy-saving control unit 30B derives the set value Qmax3 as the command value Qn when the actual control pressure Pn is the first set pressure Px. As a result, the main pump 14 is controlled to achieve the maximum swash plate tilt angle, enabling the main pump 14 to discharge the maximum discharge rate of hydraulic oil.

[0106] The same applies to the case where the arm 5 is decelerated or stopped while it is open. For example, when the left operating lever 26L is returned from the full lever operation state to the fine operation state, the amount of hydraulic oil passing through the orifice 18 increases. This is because most of the hydraulic oil discharged by the main pump 14 is discharged to the hydraulic oil tank T1 through the center bypass pipe CB.

[0107] As the amount of hydraulic oil passing through the orifice 18 increases, the control pressure Pn (negative control pressure) also increases, causing the command value Qn to decrease as shown in FIG. 6 . If the inclined line GL were fixed to the inclined line GL3, the command value Qn would decrease at a greater rate than if the inclined line GL were fixed to the inclined line GL1, and would reach the minimum command value Qmin. Because of the relatively large inclination (decrease rate) of the inclined line GL3, the decrease rate of the discharge rate of the main pump 14 relative to the decrease in the lever operation amount of the left operating lever 26L would also be excessively large, potentially making it difficult for the operator to perform a stable arm-opening operation. This is because the excavator 100 would swing back and forth, just as when starting the arm-opening operation.

[0108] In contrast, when the inclined line GL1 is used as the inclined line GL corresponding to the lever operation amount (fine operation) of the left operating lever 26L immediately before the arm 5 stops, the upper limit of the command value Qn is limited to the set value Qmax1, which is smaller than the set value Qmax3. Therefore, the rate of decrease in the discharge rate of the main pump 14 relative to a decrease in the lever operation amount of the left operating lever 26L is kept lower than when the inclined line GL3 is used as the inclined line GL. As a result, the swinging of the excavator 100 in the fore-and-aft direction when decelerating the arm 5 is suppressed, allowing the operator to smoothly decelerate the arm 5.

[0109] Furthermore, as shown in FIG. 6, the upper end point A of the inclined line GL becomes lower as the lever operation amount of the left operating lever 26L decreases, so that the discharge volume of the main pump 14 does not change suddenly when the lever operation amount of the left operating lever 26L is gradually reduced.

[0110] That is, by displacing the upper end point A as described above, the energy saving control unit 30B can prevent the discharge amount Q from becoming unstable when the arm opening operation is decelerated.

[0111] In this way, the controller 30 can more flexibly control the discharge rate Q of the main pump 14 by changing the flow rate control characteristics of the negative control in accordance with the operation of the left operating lever 26L, that is, by displacing the upper end point A in the vertical axis direction. Specifically, the energy-saving control unit 30B can suppress or prevent the amount of hydraulic oil flowing into the arm cylinder 8 from becoming unstable by adjusting the inclined line GL in accordance with the lever operation amount of the left operating lever 26L. Therefore, the energy-saving control unit 30B can smoothly open the arm 5 in accordance with, for example, operation of the left operating lever 26L in the arm-opening direction.

[0112] The above explanation with reference to Figure 6 relates to when the left operating lever 26L is operated in the arm opening direction, but it also applies to when the left operating lever 26L is operated in the arm closing direction, when the left operating lever 26L is operated in the left-right direction, when the right operating lever 26R is operated in the front-rear direction, when the right operating lever 26R is operated in the left-right direction, when the travel lever 26D is operated in the front-rear direction, and when the travel pedal is operated in the front-rear direction.

[0113] Next, a process in which the controller 30 restricts the movement of the driven body (hereinafter referred to as "movement restriction process") will be described with reference to Fig. 7. Fig. 7 is a flowchart of an example of the movement restriction process. The controller 30 repeatedly executes this movement restriction process at a predetermined control period.

[0114] First, the controller 30 determines whether the operation device 26 has been operated (step ST1). In this embodiment, the controller 30 determines whether the operation device 26 has been operated based on the output of the operation sensor 29. For example, the controller 30 determines whether an arm closing operation and an arm opening operation have been performed based on the output of the operation sensor 29LA, and determines whether a left turning operation and a right turning operation have been performed based on the output of the operation sensor 29LB. Alternatively, the controller 30 determines whether a boom raising operation and a boom lowering operation have been performed based on the output of the operation sensor 29RA, and determines whether a bucket closing operation and a bucket opening operation have been performed based on the output of the operation sensor 29RB. Similarly, the controller 30 determines whether a forward operation of the left crawler 1CL has been performed and whether a reverse operation of the left crawler 1CL has been performed based on the output of the operation sensor 29DL, and determines whether a forward operation of the right crawler 1CR has been performed and whether a reverse operation of the right crawler 1CR has been performed based on the output of the operation sensor 29DR.

[0115] When it is determined that the operation device 26 has not been operated (NO in step ST1), the controller 30 ends the current operation restriction process.

[0116] If it is determined that the operating device 26 has been operated (YES in step ST1), the controller 30 determines whether work is being performed at a predetermined work site (step ST2). In this embodiment, the controller 30 determines whether work is being performed at a predetermined work site, i.e., whether the shovel 100 is located at a predetermined work site, based on an image acquired by an imaging device serving as the object detection device 70. For example, the controller 30 determines that work is being performed at a predetermined work site when it detects an image of a road cone, a traffic cone bar, an A-type barricade, a single-pipe barricade, or a guard fence in the image acquired by the imaging device. Note that the controller 30 may also determine whether the shovel 100 is located at a predetermined work site based on the output of the positioning device 85. For example, the controller 30 determines that work is being performed at a predetermined work site when the current position of the shovel 100 is included within a geographical range preset as the range of the predetermined work site. In this case, the geographical range may be defined by multiple location information (latitude, longitude, and altitude).

[0117] The predetermined work site may be, for example, a work site in an urban area, or a work site adjacent to a roadway, sidewalk, cliff, or hole. Alternatively, the predetermined work site may be a work site where predetermined work, such as deep excavation work or crane work, is performed. The predetermined work site may be a work site where work by the excavator 100 is performed in an area smaller than the maximum work radius circular area (an area represented by a circle centered on the swing axis and having a radius equal to the distance between the position reached by the attachment AT when the attachment AT is fully extended and the swing axis) due to the presence of objects around the excavator 100. In this case, the controller 30 may determine that the predetermined work (deep excavation work) is being performed when an image of a hole deeper than a predetermined depth is detected in an image acquired by the imaging device. Alternatively, the controller 30 may determine that the predetermined work (crane work) is being performed when an image of a load lifted by the attachment AT is detected in an image acquired by the imaging device.

[0118] If it is determined that the work is not being performed at a predetermined work site (NO in step ST2), the controller 30 ends the current operation restriction process.

[0119] If it is determined that the work is being performed at a predetermined work site (YES in step ST2), the controller 30 restricts the movement of the driven body (step ST3). In this embodiment, the controller 30 restricts the movement of the driven body by controlling the discharge rate of the main pump 14. The driven body is at least one of the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, and the bucket 6.

[0120] With this configuration, the controller 30 can restrict the movement of the driven body when the shovel 100 is located within a predetermined work site. For example, the controller 30 can suppress the operating speed of the attachment AT when it starts to move. As a result, the controller 30 can more reliably prevent, for example, the attachment AT from coming into contact with objects around the attachment AT.

[0121] Next, with reference to FIG. 8 , another example of the contents of the lookup table referred to by the energy-saving control unit 30B will be described. FIG. 8 is a diagram showing another example of the correspondence relationship (flow control characteristic) between the control pressure Pn and the command value Qn, which is another example of the contents of the lookup table, and corresponds to FIG. 6 . Specifically, FIG. 8 shows the flow control characteristic employed when the movement of the driven body is restricted, while FIG. 6 shows the flow control characteristic employed when the movement of the driven body is not restricted. The lookup table shown in FIG. 8 is used to control the discharge rates of the left main pump 14L and the right main pump 14R. When controlling the discharge rate of the left main pump 14L, the horizontal axis of FIG. 8 corresponds to the control pressure detected by the left control pressure sensor 19L, and the vertical axis of FIG. 8 corresponds to the command value for the discharge rate of the left main pump 14L. Similarly, when controlling the discharge rate of the right main pump 14R, the horizontal axis of FIG. 8 corresponds to the control pressure detected by the right control pressure sensor 19R, and the vertical axis of FIG. 8 corresponds to the command value for the discharge rate of the right main pump 14R.

[0122] More specifically, Fig. 8 shows the contents of the lookup table that is referenced when the left operating lever 26L is operated in the arm-opening direction, and the flow control characteristics when the left operating lever 26L is slightly operated are shown by a solid line including a sloped line GL1A. Fig. 8 also shows the flow control characteristics when the left operating lever 26L is half-operated by a dashed line including a sloped line GL2A. Fig. 8 also shows the flow control characteristics when the left operating lever 26L is fully operated by a dashed line including a sloped line GL3A.

[0123] The slope line GL1A is the same as the slope line GL1 shown in FIG. 6 in that the command value Qn increases as the control pressure Pn decreases, but differs from the slope line GL1 shown in FIG. 6 in that the rate of increase increases as the control pressure Pn decreases. The slope line GL1 shown in FIG. 6 has a constant rate of increase. The slope line GL2A is the same as the slope line GL2 shown in FIG. 6 in that the command value Qn increases as the control pressure Pn decreases, but differs from the slope line GL2 shown in FIG. 6 in that the rate of increase increases as the control pressure Pn decreases. The slope line GL3A is the same as the slope line GL3 shown in FIG. 6 in that the command value Qn increases as the control pressure Pn decreases, but differs from the slope line GL3 shown in FIG. 6 in that the rate of increase increases as the control pressure Pn decreases.

[0124] The controller 30 can appropriately limit the movement of the driven body by employing the flow control characteristics shown in FIG. 8 . For example, when the shovel 100 is located at a predetermined work site, the controller 30 can suppress the opening speed of the arm 5 when the arm 5 starts to move in response to an arm-opening operation. That is, the controller 30 can suppress the arm 5 from opening at an excessively high speed when the arm-opening operation is performed. Note that in the example shown in FIG. 8 , even when restricting the movement of the driven body including the arm 5, the controller 30 does not limit the maximum operating speed of the arm 5. That is, the controller 30 is configured so that the maximum operating speed of the arm 5 when the movement of the arm 5 is restricted is the same as the maximum operating speed of the arm 5 when the movement of the arm 5 is not restricted. This means that when the arm-opening operation is continued by full lever operation, the operating speed of the arm 5 reaches its maximum value regardless of whether the movement of the arm 5 is restricted or not. However, the time required for the operating speed of the arm 5 to reach its maximum value when the movement of the arm 5 is restricted is longer than when the movement of the arm 5 is not restricted.

[0125] Next, an example of a situation in which the movement of the driven body is restricted by the operation restriction process will be described with reference to Fig. 9. Fig. 9 is a perspective view of the excavator 100 performing crane work.

[0126] In the example shown in FIG. 9 , the excavator 100 is lifting a sewer pipe BP in order to bury the sewer pipe BP in an excavation trench EX formed in a road. The operator of the excavator 100 is attempting to perform a right swing operation in accordance with instructions from a rigging operator FS located to the left front of the excavator 100. The controller 30 continuously monitors the distance DB between the excavator 100 (bucket 6) or the sewer pipe BP and the rigging operator FS based on the output of the front camera 70F. The operator of the excavator 100 is attempting to swing the upper rotating body 3 to the right using the left operating lever 26L to bring the sewer pipe BP closer to the excavation trench EX. At this time, the rigging operator FS may get too close to the excavator 100 (bucket 6) or the sewer pipe BP, for example, to adjust the attitude of the sewer pipe BP.

[0127] In such a situation, when the controller 30 detects at least one image of an object such as a road cone RC, a guardrail GR, a utility pole EP, or a sewer pipe BP in the image acquired by the forward camera 70F, it may determine that work is being carried out at a specified work site and restrict the movement of the driven body.

[0128] Specifically, when the controller 30 detects an image of a guardrail GR or a utility pole EP in the image acquired by the forward camera 70F, it may determine that work is being carried out at a specified work site (a work site adjacent to a sidewalk or roadway) and restrict the movement of the driven body.

[0129] Alternatively, when the controller 30 detects an image of a suspended load (a sewer pipe BP lifted by a hook attached to the tip of the arm 5) in the image acquired by the forward camera 70F, it may determine that the work is being done at a specified work site (crane work) and suppress the movement of the driven body.

[0130] The suppression of the movement of the driven body may be achieved, for example, by suppressing the rise of the main pump 14, that is, by switching the flow control characteristics shown in FIG. 6 to the flow control characteristics shown in FIG. 8 . Alternatively, the suppression of the movement of the driven body may be achieved by reducing the maximum operating speed of the driven body, reducing the relief pressure of a relief valve (not shown) provided in the center bypass pipe CB, reducing the output power (rotation speed) of a power source such as the engine 11 or an electric motor, or switching the operation mode of the excavator 100. The operation mode includes, for example, an excavation mode selected when excavation work is performed and a crane mode selected when crane work is performed. In the crane mode, the amount of movement of the actuator relative to the amount of operation of the operating device 26 is smaller than in the excavation mode.

[0131] Note that when the distance DB is less than a predetermined value, the controller 30 may output a shutoff command to the control valve 60 to switch the pilot line CD1 to the shutoff state when a left turning operation is performed, in order to disable the left operating lever 26L and stop the rotation of the turning hydraulic motor 2A.

[0132] In a configuration in which the movement of the shovel 100 is uniformly restricted when an object is present around the shovel 100, not only left-turn operations but also right-turn operations are invalidated. Therefore, the controller 30 may determine whether or not it is permissible to move the driven body for each operation performed via the operating device 26. In this case, in a situation such as that shown in FIG. 9 , the controller 30 can prohibit rotation of the swing hydraulic motor 2A in response to a left-turn operation by the operator, while allowing rotation of the swing hydraulic motor 2A in response to a right-turn operation by the operator. This is because the controller 30 can determine that there is no risk of the shovel 100 and the object coming too close, even if the shovel 100 is turned right. As a result, the controller 30 can quickly bring the sewer pipe BP closer to the excavation trench EX while preventing the shovel 100 (bucket 6) or the sewer pipe BP from coming too close to the slinging operator FS.

[0133] Alternatively, the controller 30 may be configured not to restrict the movement of the driven body until the distance DB between the shovel 100 (bucket 6) or the sewer pipe BP and the slinging operator FS becomes less than a predetermined value, even when the shovel 100 is located at a predetermined work site. In other words, the controller 30 may be configured to restrict the movement of the driven body only when the operation of the driven body is started in a state where the distance DB is less than the predetermined value.

[0134] Furthermore, the controller 30 may be configured to notify at least one of the operator of the excavator 100 and the rigging operator FS when the distance DB falls below a predetermined value. In the illustrated example, when the controller 30 determines that the distance DB has fallen below the predetermined value based on the image acquired by the forward camera 70F, it causes the exterior alarm 45A and the interior alarm 45B to output an alarm sound. This is to attract the attention of the operator and the rigging operator FS. Note that the controller 30 may also attract the operator's attention by displaying image information on the display device 40 informing that the distance DB has fallen below the predetermined value, or may attract the attention of the rigging operator FS by turning on a rotating light attached to the exterior of the cabin 10.

[0135] With the above-described configuration, the controller 30 can more reliably prevent contact between the attachment AT and objects present around the attachment AT when the shovel 100 is located at a work site where crane work is being performed.

[0136] Next, another example of a situation in which the movement of the driven body is restricted by the operation restriction process will be described with reference to Fig. 10. Fig. 10 is a side view of the shovel 100 performing deep digging work.

[0137] In the example shown in FIG. 10 , the excavator 100 is digging the hole HL deep by inserting the bucket 6 into the hole HL. A worker WK is waiting in the hole HL near the bucket 6 to monitor the work status. The worker WK sends a signal to the operator of the excavator 100 as needed. The operator of the excavator 100 follows the signal from the worker WK and loads the soil at the bottom of the hole HL into the bucket 6, then loads the soil into the bed of a dump truck DT parked near the excavator 100. The controller 30 continuously monitors whether the worker WK is near the bucket 6 based on the output of the attachment camera 70A. In the illustrated example, the controller 30 monitors whether the worker WK is within a predetermined distance DS (within the range indicated by the dashed line L1) from the connecting pin 6P that connects the arm 5 and the bucket 6. The dashed-dotted line L2 in FIG. 10 represents the imaging range of the attachment camera 70A.

[0138] The operator of the excavator 100 is using the operating device 26 to perform a combined operation including an arm closing operation and a bucket closing operation to collect earth and sand in the hole HL into the bucket 6. At this time, the worker WK may get too close to the bucket 6, for example, to check the position (depth) of the tip of the bucket 6.

[0139] In such a situation, when the controller 30 detects the worker WK within a predetermined distance DS from the connecting pin 6P based on the image acquired by the attachment camera 70A, the controller 30 may determine that the work is being performed at a predetermined work site (a work site where deep excavation work is being performed) and may restrict the movement of the driven body. In other words, the controller 30 may determine that the worker WK is present near the bucket 6 and may restrict the movement of the driven body.

[0140] In the illustrated example, by switching the flow control characteristics as shown in Fig. 6 to the flow control characteristics as shown in Fig. 8, the controller 30 can suppress the rate of increase in the operating speed when the attachment AT starts to move, compared to when the movement of the driven body is not restricted. In other words, the controller 30 can suppress the rate of increase in the discharge rate of the main pump 14 in response to an increase in the operation amount of the operating device 26, compared to when the movement of the driven body is not restricted. Note that even when restricting the movement of the driven body in this way, the controller 30 does not impose a limit on the maximum operating speed of the attachment AT (maximum command value Qmax corresponding to the maximum discharge rate of the main pump 14).

[0141] Specifically, for example, the controller 30 can slow down the lowering movement of the boom 4 when the operator starts a boom lowering operation in order to enter the bucket 6 located above the hole HL into the hole HL. In other words, compared to when the movement of the driven body (boom 4) is not restricted, the controller 30 can restrict the descent speed of the boom 4 by reducing the rate of increase in the flow rate of hydraulic oil flowing into the rod-side oil chamber of the boom cylinder 7 in response to an increase in the lever operation amount of the right operating lever 26R in the boom lowering direction until that lever operation amount reaches a predetermined lever operation amount.

[0142] Furthermore, the controller 30 can slow down the closing movement of the arm 5 when, for example, the operator starts an arm closing operation in order to excavate earth and sand at the bottom of the hole HL with the bucket 6 that has reached the bottom of the hole HL. Similarly, the controller 30 can slow down the raising movement of the boom 4 when, for example, the operator starts a boom raising operation in order to lift up the earth and sand that has been taken into the bucket 6.

[0143] On the other hand, the controller 30 does not slow down the boom-raising and swinging operation (combined operation including a swing operation and a boom-raising operation) when the operator starts a combined operation including a swing operation and a boom-raising operation to raise the boom 4 while rotating the upper rotating body 3 with the bucket 6 lifted above the hole HL. This is because the controller 30 can determine that the worker WK is not present within the predetermined distance DS from the connecting pin 6P when the bucket 6 is lifted above the hole HL. This allows the operator to perform unlimited boom-raising and swinging operations and quickly load earth and sand into the bed of the dump truck DT without stress. Furthermore, the controller 30 does not slow down the boom-lowering and swinging operation (combined operation including a swing operation and a boom-lowering operation) when the operator starts a combined operation including a swing operation and a boom-lowering operation to move the bucket 6 from above the bed of the dump truck DT to above the hole HL. The detection target does not necessarily have to be the worker WK. For example, the controller 30 may determine whether or not the actuator's operation needs to be restricted based on whether or not a pre-registered object other than earth and sand, such as a guardrail GR, a utility pole EP, or a sewer pipe BP, has been detected. Furthermore, the controller 30 may determine whether or not the actuator's operation needs to be restricted based on the angle (slope) of the side wall of the hole HL in Fig. 10 , the presence or absence of a safety device (such as the presence or absence of a trench box), the presence or absence of vibrations associated with the operation of the excavator, and the like. In this way, the controller 30 can improve the safety of the work site by determining whether or not the actuator's operation needs to be restricted based on the presence or absence of an object in the work area, etc.

[0144] In addition, suppression of the movement of the driven body may be achieved by reducing the maximum operating speed of the driven body, reducing the relief pressure of a relief valve (not shown) provided in the center bypass pipe CB, reducing the output power (rotation speed) of a power source such as the engine 11 or an electric motor, or switching the operating mode of the excavator 100.

[0145] With the above-described configuration, the controller 30 can more reliably prevent contact between the attachment AT and objects around the attachment AT, even when the shovel 100 is located at a work site where deep excavation work is being performed.

[0146] Next, an operation status screen, which is a screen displayed on the display device 40 while the excavator 100 is operating, will be described with reference to Figures 11 and 12. Figures 11 and 12 show examples of the configuration of the operation status screen.

[0147] The display device 40 has a control unit 40a, an image display unit 41, and an operation unit 42. The control unit 40a controls the image displayed on the image display unit 41. In this embodiment, the control unit 40a is configured as a computer including a CPU, a volatile storage device, a non-volatile storage device, etc. In this case, the control unit 40a reads out programs corresponding to each function from the non-volatile storage device, loads them into the volatile storage device, and causes the CPU to execute the corresponding process.

[0148] The image display unit 41 includes a date and time display area 41a, a driving mode display area 41b, an end attachment display area 41c, a fuel efficiency display area 41d, an engine control status display area 41e, an engine operating time display area 41f, a coolant temperature display area 41g, a remaining fuel amount display area 41h, a rotation speed mode display area 41i, a urea water remaining amount display area 41j, a hydraulic oil temperature display area 41k, an air conditioner operating status display area 41m, an image display area 41n, and a menu display area 41p.

[0149] The travel mode display area 41b, the end attachment display area 41c, the engine control state display area 41e, the rotation speed mode display area 41i, and the air conditioner operation state display area 41m are areas that display setting state information, which is information about the setting state of the excavator 100. The fuel consumption display area 41d, the engine operating time display area 41f, the coolant temperature display area 41g, the remaining fuel amount display area 41h, the remaining urea water amount display area 41j, and the hydraulic oil temperature display area 41k are areas that display operating state information, which is information about the operating state of the excavator 100.

[0150] The date and time display area 41a is an area that displays the current date and time. The travel mode display area 41b is an area that displays the current travel mode. The end attachment display area 41c is an area that displays an image representing the currently attached end attachment. The fuel efficiency display area 41d is an area that displays fuel efficiency information calculated by the controller 30. The fuel efficiency display area 41d includes an average fuel efficiency display area 41d1 that displays the average fuel efficiency for the entire period or the average fuel efficiency for a partial period, and an instantaneous fuel efficiency display area 41d2 that displays the instantaneous fuel efficiency. The entire period means, for example, the entire period after the excavator 100 is shipped. The partial period means, for example, a period arbitrarily set by the operator.

[0151] The engine control status display area 41e is an area that displays the control status of the engine 11. The engine operating time display area 41f is an area that displays information related to the operating time of the engine 11. The coolant temperature display area 41g is an area that displays the current temperature state of the engine coolant. The remaining fuel amount display area 41h is an area that displays the remaining amount of fuel stored in the fuel tank. The rotation speed mode display area 41i is an area that displays, as an image, the current rotation speed mode set by the engine rotation speed adjustment dial 75. The urea water remaining amount display area 41j is an area that displays, as an image, the remaining amount of urea water stored in the urea water tank. The hydraulic oil temperature display area 41k is an area that displays the temperature state of the hydraulic oil in the hydraulic oil tank.

[0152] The air conditioner operation status display area 41m includes an air outlet display area 41m1 that displays the current air outlet position, an operation mode display area 41m2 that displays the current operation mode, a temperature display area 41m3 that displays the current set temperature, and an air volume display area 41m4 that displays the current set air volume.

[0153] The image display area 41n is an area where an image captured by the imaging device is displayed. The image display area 41n has a first image display area 41n1 located above and a second image display area 41n2 located below. In the example shown in FIGS. 11 and 12 , the bucket-periphery image BG is arranged in the first image display area 41n1, and the overhead-view image FV is arranged in the second image display area 41n2. However, the image display area 41n may also arrange the bucket-periphery image BG in the second image display area 41n2, and the overhead-view image FV in the first image display area 41n1. Furthermore, although the bucket-periphery image BG and the overhead-view image FV are arranged adjacent to each other vertically in the example shown in FIGS. 11 and 12 , they may also be arranged with an interval between them.

[0154] The bucket surrounding image BG is an image displayed when deep digging work is being performed, and is an image generated based on an image acquired by the attachment camera 70A. The bucket surrounding image BG may be an image that has undergone viewpoint conversion processing, or an image that has not undergone viewpoint conversion processing. The bucket surrounding image BG may also be a CG image that includes an arm image 5G (a CG image showing the position of the arm 5), a bucket image 6G (a CG image showing the position of the bucket 6), and a worker image WG (a CG image showing the position of a worker WK working around the bucket 6).

[0155] In the illustrated example, the bucket peripheral image BG includes a first bucket peripheral image BG1 (see FIG. 11) and a second bucket peripheral image BG2 (see FIG. 12). The first bucket peripheral image BG1 is an image that shows the state inside the hole HL that is the target of deep excavation work when viewed from above, and the second bucket peripheral image BG2 is an image that shows the position inside the hole HL that is the target of deep excavation work when viewed from the side.

[0156] As shown in Fig. 11 , the first bucket peripheral image BG1 includes an arm image 5G, a bucket image 6G, and a worker image WG. In Fig. 11 , the arm image 5G indicates the position of the arm 5 when viewed from above, the bucket image 6G indicates the position of the bucket 6 when viewed from above the hole HL, and the worker image WG indicates the position of the worker WK when viewed from above the hole HL. By looking at the first bucket peripheral image BG1, the operator of the excavator 100 can recognize that the worker WK is present diagonally forward and to the left of the bucket 6 within the hole HL.

[0157] As shown in FIG. 12 , the second bucket peripheral image BG2 includes a shovel image 100G, a hole image HG, and a worker image WG. The shovel image 100G is a CG image showing the position of the shovel 100 when viewed from the side, and includes an arm image 5G and a bucket image 6G. The hole image HG is a CG image showing the position of the hole HL that is the target of deep excavation work. In FIG. 12 , the arm image 5G shows the position of the arm 5 when the work site is viewed from the side, the bucket image 6G shows the position of the bucket 6 when the work site is viewed from the side, the worker image WG shows the position of the worker WK when the work site is viewed from the side, and the hole image HG shows the position of the hole HL when the work site is viewed from the side. By looking at the second bucket peripheral image BG2, the operator of the shovel 100 can recognize that the worker WK is present in front of the bucket 6 at approximately the same height as the bucket 6.

[0158] The overhead image FV is a virtual viewpoint image generated by the control unit 40a, and is generated based on images acquired by the rear camera 70B, the left camera 70L, and the right camera 70R. Furthermore, a shovel graphic GE corresponding to the shovel 100 is placed in the center of the overhead image FV. This is to allow the operator to more intuitively grasp the positional relationship between the shovel 100 and objects existing around the shovel 100.

[0159] 11 and 12, the image display area 41n is a vertically long area, but it may also be a horizontally long area. When the image display area 41n is a horizontally long area, the image display area 41n may include an overhead image FV as a first image display area 41n1 on the left side and a bucket surrounding image BG as a second image display area 41n2 on the right side. In this case, the overhead image FV may be positioned to the left of the bucket surrounding image BG with a gap therebetween. Alternatively, the overhead image FV may be positioned to the right of the bucket surrounding image BG.

[0160] 11 and 12, the tab areas 41p1 to 41p7 are arranged at intervals on the left and right at the bottom of the image display section 41. An icon representing the content of related information is displayed in each of the tab areas 41p1 to 41p7.

[0161] In the tab area 41p1, menu detail item icons for displaying the menu detail items are displayed. When the operator selects the tab area 41p1, the icons displayed in the tab areas 41p2 to 41p7 are switched to icons associated with the menu detail items.

[0162] The tab area 41p4 displays an icon for displaying information related to the digital level. When the operator selects the tab area 41p4, the bucket surroundings image BG is switched to a first screen showing information related to the digital level.

[0163] The tab area 41p6 displays icons for displaying information related to information-based construction. When the operator selects the tab area 41p6, the bucket surrounding image BG is switched to a second screen showing information related to information-based construction.

[0164] In the tab area 41p7, an icon for displaying information relating to the crane mode is displayed. When the operator selects the tab area 41p7, the bucket surroundings image BG is switched to the third screen showing information relating to the crane mode.

[0165] However, any of the menu screens, such as the first screen, second screen, or third screen, may be superimposed on the bucket surroundings image BG. Alternatively, the bucket surroundings image BG may be reduced in size to make room for displaying the menu screen. Alternatively, the overhead-view image FV may be configured to switch to the menu screen. Alternatively, the menu screen may be superimposed on the overhead-view image FV. Alternatively, the overhead-view image FV may be reduced in size to make room for displaying the menu screen.

[0166] 11 and 12, no icons are displayed in the tab areas 41p2, 41p3, and 41p5. Therefore, even if the operator operates the tab areas 41p2, 41p3, or 41p5, no change occurs in the image displayed on the image display unit 41.

[0167] The icons displayed in the tab areas 41p1 to 41p7 are not limited to the examples described above, and icons for displaying other information may be displayed.

[0168] In the example shown in FIGS. 11 and 12 , the operation unit 42 is configured with multiple button-type switches that allow the operator to select tab areas 41p1 to 41p7 and input settings. Specifically, the operation unit 42 includes seven switches 42a1 to 42a7 arranged in an upper row and seven switches 42b1 to 42b7 arranged in a lower row. Switches 42b1 to 42b7 are arranged below switches 42a1 to 42a7, respectively. However, the number, shape, and arrangement of the switches in the operation unit 42 are not limited to the above example. For example, the operation unit 42 may be configured as a jog wheel or jog switch, combining the functions of multiple button-type switches into one. The operation unit 42 may also be configured as a component independent of the display device 40. The tab areas 41p1 to 41p7 may also be configured as software buttons. In this case, the operator can select any tab area by touching the tab areas 41p1 to 41p7.

[0169] 11 and 12, the switch 42a1 is disposed below the tab area 41p1 in correspondence with the tab area 41p1, and functions as a switch for selecting the tab area 41p1. The same applies to each of the switches 42a2 to 42a7.

[0170] This configuration allows the operator to intuitively recognize which of the switches 42a1 to 42a7 to operate when selecting a desired one of the tab areas 41p1 to 41p7.

[0171] The switch 42b1 is a switch that switches the captured image displayed in the image display area 41n. The display device 40 is configured so that each time the switch 42b1 is operated, the captured image displayed in the first image display area 41n1 of the image display area 41n is switched in the order of, for example, the rear image, the left image, the right image, the overhead image FV, and the bucket-periphery image BG. Alternatively, the display device 40 may be configured so that each time the switch 42b1 is operated, the captured image displayed in the second image display area 41n2 of the image display area 41n is switched in the order of, for example, the rear image, the left image, the right image, the overhead image FV, and the bucket-periphery image BG. Alternatively, the display device 40 may be configured so that each time the switch 42b1 is operated, the captured image displayed in the first image display area 41n1 of the image display area 41n is swapped with the captured image displayed in the second image display area 41n2.

[0172] In this way, the operator may switch between the screens displayed in the first image display area 41n1 and the second image display area 41n2 by operating the switch 42b1 of the operation unit 42. Alternatively, the operator may switch between the screens displayed in the first image display area 41n1 and the second image display area 41n2 by operating the switch 42b1. The display device 40 may also be provided with a separate switch for switching between the screens displayed in the second image display area 41n2.

[0173] 11 and 12, the operation unit 42 is configured so that the air volume of the air conditioner is reduced when the switch 42b2 is operated, and is increased when the switch 42b3 is operated.

[0174] The switch 42b4 is a switch that switches the cooling and heating functions ON and OFF. In the example shown in Figures 11 and 12, the operation unit 42 is configured so that the cooling and heating functions are switched ON and OFF every time the switch 42b4 is operated.

[0175] The switches 42b5 and 42b6 are switches for adjusting the set temperature of the air conditioner. In the example shown in Figures 11 and 12, the operation unit 42 is configured so that when the switch 42b5 is operated, the set temperature is lowered, and when the switch 42b6 is operated, the set temperature is raised.

[0176] The switch 42b7 is a switch for switching the content of information displayed in the engine operation time display area 41f regarding the operation time of the engine 11. The information regarding the operation time of the engine 11 includes, for example, the accumulated operation time for the entire period and the accumulated operation time for a partial period.

[0177] Switches 42a2 to 42a6 and 42b2 to 42b6 are configured to allow the user to input numbers displayed on or near the switches, while switches 42a3, 42a4, 42a5, and 42b4 are configured to allow the user to move the cursor left, up, right, and down, respectively, when the cursor is displayed on image display unit 41.

[0178] The above-described functions given to the switches 42a1 to 42a7 and 42b1 to 42b7 are merely examples, and the switches 42a1 to 42a7 and 42b1 to 42b7 may be configured to perform other functions.

[0179] As described above, as shown in FIG. 1 , the excavator 100 according to the embodiment of the present disclosure includes a lower traveling body 1, an upper rotating body 3 mounted on the lower traveling body 1, an attachment AT including an end attachment such as a bucket 6 mounted on the upper rotating body 3, a controller 30 as a control device mounted on the upper rotating body 3, and actuators such as a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 that move the attachment AT. The controller 30 is configured to control the movement of the actuators at a predetermined work site. Specifically, the controller 30 is configured to promote or suppress the movement of the actuators. The promotion of the movement of the actuators may be achieved, for example, by promoting the rise of the main pump 14, that is, by switching the flow control characteristic shown in FIG. 8 to the flow control characteristic shown in FIG. 6. Alternatively, the promotion of the movement of the actuator may be achieved by increasing the maximum operating speed of the actuator, increasing the relief pressure of a relief valve (not shown) provided in the center bypass pipe CB, increasing the output power (rotation speed) of a power source such as the engine 11 or an electric motor, or switching the operation mode of the excavator 100. The suppression of the movement of the actuator may be achieved, for example, by suppressing the rise of the main pump 14, that is, by switching the flow control characteristics shown in FIG. 6 to the flow control characteristics shown in FIG. 8. Alternatively, the suppression of the movement of the actuator may be achieved by stopping the actuator, reducing the maximum operating speed of the actuator, reducing the relief pressure of a relief valve (not shown) provided in the center bypass pipe CB, reducing the output power (rotation speed) of a power source such as the engine 11 or an electric motor, or switching the operation mode of the excavator 100.

[0180] With this configuration, the controller 30 can more reliably prevent contact between the attachment and objects present around the attachment. This is because the movement of the actuator can be suppressed when the shovel 100 is located at a specific work site, such as a work site in an urban area, where a situation may arise in which the worker is forced to work near the attachment. On the other hand, the controller 30 can promote the movement of the actuator when the shovel 100 is located at a work site other than the specific work site where a situation may arise in which the worker is forced to work near the attachment. Therefore, the controller 30 can increase the work efficiency of the shovel 100 when the shovel 100 is located at a work site other than the specific work site.

[0181] The controller 30 may be configured to determine whether or not the operator is at a predetermined work site based on information acquired by the information acquisition device, and to promote or suppress the movement of the actuator when it is determined that the operator is at the predetermined work site. The information acquisition device may be, for example, a positioning device 85, an imaging device, or a communication device. The information acquisition device may be a switch (a switch provided on the display device 40, etc.) that the operator can operate to notify the controller 30 that the operator is at the predetermined work site.

[0182] Specifically, the controller 30 may be configured to determine whether or not the robot is at a specified work site based on location information acquired by the positioning device 85 as an information acquisition device, and to promote or suppress the movement of the actuator if it is determined that the robot is at the specified work site.

[0183] Alternatively, the controller 30 may be configured to determine whether or not the person is at a specified work site based on images acquired by an imaging device serving as an information acquisition device, and to promote or suppress the movement of the actuator if it is determined that the person is at the specified work site.

[0184] With this configuration, the controller 30 can more reliably prevent contact between the attachment and objects present around the attachment while preventing excessive restriction on the movement of the driven body. This is because the controller 30 can more accurately determine whether the shovel 100 is located at a predetermined work site where the movement of the driven body should be restricted. In other words, the controller 30 can suppress or prevent the current work site from being erroneously determined to be the predetermined work site.

[0185] 1 , a shovel 100 according to another embodiment of the present disclosure includes a lower traveling body 1, an upper rotating body 3 mounted on the lower traveling body 1, an attachment AT including an end attachment such as a bucket 6 mounted on the upper rotating body 3, actuators such as a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 that move the attachment AT, and a controller 30 as a control device that detects objects present around the end attachment. The controller 30 is configured to suppress movement of the actuators when it detects an object present around the end attachment.

[0186] With this configuration, the controller 30 can more reliably prevent contact between the attachment and objects present around the attachment. Furthermore, the controller 30 is configured to suppress the movement of the actuator rather than stop the movement of the actuator when an object present around the end attachment is detected. This allows the operator of the shovel 100 to continue working with the shovel 100 even when a worker is present around the end attachment. As a result, this configuration can suppress a decrease in the work efficiency of the shovel 100 even when a worker is present around the end attachment.

[0187] The controller 30 may be configured to detect objects present around the end attachment based on images acquired by an imaging device attached to the attachment AT.

[0188] In the example shown in FIG. 10 , the controller 30 is configured to detect objects present around the bucket 6 based on images acquired by an attachment camera 70A attached to the bucket cylinder 9. However, the controller 30 may also be configured to detect objects present around the bucket 6 based on images acquired by at least one of a rear camera 70B, a front camera 70F, a left camera 70L, and a right camera 70R attached to the upper rotating body 3. Alternatively, the controller 30 may be configured to detect objects present around the bucket 6 based on images acquired by an external camera installed outside the excavator 100. Specifically, as shown in FIG. 10 , the controller 30 may be configured to detect objects present around the bucket 6 based on images acquired by a camera 70D mounted on an air vehicle 50 or images acquired by a fixed camera 70P attached to a pole 55 installed at the work site. The air vehicle 50 is an autonomous air vehicle that can be flown by remote control or automatic piloting, and includes, for example, a multicopter, an airship, or the like.

[0189] With this configuration, the controller 30 can more reliably prevent contact between the attachment and objects present around the attachment while preventing excessive restriction of the movement of the driven body. This is because the controller 30 can more accurately detect whether or not an object is present around the end attachment. In other words, the controller 30 can suppress or prevent erroneous detection of an object.

[0190] Furthermore, the controller 30 may be configured to alert at least one of the operator and the worker when it detects a worker present around the end attachment.

[0191] With this configuration, the controller 30 can more reliably prevent contact between the attachment and a worker present around the attachment.

[0192] The actuators are typically hydraulic actuators. The controller 30 may be configured to promote or suppress the movement of the hydraulic actuators by controlling the movement of at least one of a hydraulic pump such as the main pump 14 that supplies hydraulic oil to the hydraulic actuators, a control valve such as the control valves 171 to 176 that control the flow rate of hydraulic oil flowing into the hydraulic actuators, and a power source such as the engine 11 that drives the hydraulic pumps. However, the actuators may also be electric actuators.

[0193] Furthermore, information acquired by the shovel 100 may be shared with an administrator, other shovel operators, and the like through a shovel control system SYS as shown in FIG. 13 . FIG. 13 is a schematic diagram showing an example of the configuration of a shovel control system SYS. The control system SYS is a system that controls the shovel 100. In this embodiment, the control system SYS is mainly composed of the shovel 100, a support device 200, and a management device 300. The shovel 100, the support device 200, and the management device 300 each include a communication device and are directly or indirectly connected to each other via a mobile phone communication network, a satellite communication network, a short-range wireless communication network, or the like. The shovel 100, the support device 200, and the management device 300 constituting the control system SYS may each be one or more. In the example of FIG. 13 , the control system SYS includes one shovel 100, one support device 200, and one management device 300.

[0194] The support device 200, which is a device that supports the control of the shovel 100, is typically a mobile terminal device, and is, for example, a computer such as a notebook PC, tablet PC, or smartphone carried by a worker or the like at a work site. The support device 200 may also be a computer carried by the operator of the shovel 100. However, the support device 200 may also be a fixed terminal device.

[0195] The management device 300, which is a device for managing various types of information, is typically a fixed terminal device, such as a server computer installed in a management center outside the work site, etc. The management device 300 may also be a portable computer (for example, a portable terminal device such as a notebook PC, tablet PC, or smartphone).

[0196] At least one of the support device 200 and the management device 300 may be equipped with a monitor and an operating device for remote operation. In this case, the shovel 100 and at least one of the support device 200 and the management device 300 constitute a remote operation system for the shovel. A remote operator can operate the shovel 100 using the operating device for remote operation. The operating device for remote operation is connected to the controller 30 via a communication network such as a mobile phone communication network, a satellite communication network, or a short-range wireless communication network. In this configuration, the control system SYS may be configured so that a user of the support device 200 can intervene in the operation of the shovel 100 by the operator of the shovel 100 or the remote operator. In this case, the user of the support device 200 can intervene in the operation of the shovel 100 while, for example, near the edge of the hole HL while observing the positional relationship between the worker WK in the hole HL and the bucket 6 of the shovel 100, thereby ensuring the safety of the worker WK.

[0197] The controller 30 may be included in the support device 200 or in the management device 300. In addition, all or part of the functions executed by the controller 30 may be executed by the support device 200 or in the management device 300.

[0198] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments, nor is it limited to the embodiments described below. Various modifications or substitutions may be applied to the above-described or below-described embodiments without departing from the scope of the present invention. Furthermore, features described separately may be combined unless technical contradictions arise.

[0199] For example, in the above-described embodiment, the controller 30 is configured to suppress the movement of the driven body when it determines that the work is being performed at a specified work site, but it may also be configured to promote the movement of the driven body.

[0200] The promotion of the movement of the driven body may be achieved, for example, by promoting the rise of the main pump 14, that is, by switching the flow control characteristics as shown in Fig. 8 to the flow control characteristics as shown in Fig. 6. Alternatively, the promotion of the movement of the driven body may be achieved by increasing the maximum operating speed of the driven body, increasing the relief pressure of a relief valve (not shown) provided in the center bypass pipe CB, increasing the output power (rotation speed) of a power source such as the engine 11 or an electric motor, or switching the operation mode of the excavator 100.

[0201] Furthermore, the above-described embodiment discloses a hydraulic control lever equipped with a hydraulic pilot circuit. For example, in the hydraulic pilot circuit for the left control lever 26L, hydraulic oil supplied from the pilot pump 15 to the left control lever 26L is transmitted to the pilot port of the control valve 176 at a flow rate corresponding to the aperture of a remote control valve that is opened or closed by tilting the left control lever 26L in the arm-opening direction. Alternatively, in the hydraulic pilot circuit for the right control lever 26R, hydraulic oil supplied from the pilot pump 15 to the right control lever 26R is transmitted to the pilot port of the control valve 175 at a flow rate corresponding to the aperture of a remote control valve that is opened or closed by tilting the right control lever 26R in the boom-raising direction.

[0202] However, instead of a hydraulic control lever equipped with such a hydraulic pilot circuit, an electric control system equipped with an electric control lever may be employed. In this case, the lever operation amount of the electric control lever is input to the controller 30 as, for example, an electric signal. Furthermore, a solenoid valve is disposed between the pilot pump 15 and the pilot port of each control valve. The solenoid valve is configured to operate in response to an electric signal from the controller 30. With this configuration, when manual operation is performed using the electric control lever, the controller 30 controls the solenoid valve with an electric signal corresponding to the lever operation amount to increase or decrease the pilot pressure, thereby moving each control valve (each spool valve) to a desired position.

[0203] When an electric operation system equipped with an electric operation lever is employed, the controller 30 can easily switch between a manual control mode and an automatic control mode. The manual control mode is a mode in which the actuator is operated in response to manual operation of the operation device 26 by an operator, and the automatic control mode is a mode in which the actuator is operated regardless of manual operation. When the controller 30 switches from the manual control mode to the automatic control mode, the multiple control valves (spool valves) may be controlled separately in response to an electric signal corresponding to the lever operation amount of one electric operation lever.

[0204] This application claims priority based on Japanese Patent Application No. 2022-061307, filed on March 31, 2022, the entire contents of which are incorporated herein by reference.

[0205] DESCRIPTION OF SYMBOLS 1... Lower traveling body 1C... Crawler 1CL... Left crawler 1CR... Right crawler 2... Swing mechanism 2A... Swing hydraulic motor 2M... Travel hydraulic motor 2ML... Left traveling hydraulic motor 2MR... Right traveling hydraulic motor 3... Upper rotating body 4... Boom 5... Arm 6... Bucket 7... Boom cylinder 8... Arm cylinder 9... Bucket cylinder 10... Cabin 11... Engine 13... Pump regulator 14... Main pump 15... Pilot pump 17... Control valve unit 18... Throttle 19... Control pressure sensor 26... Operation device 26D... Travel lever 26DL... Left traveling lever 26DR... Right traveling lever 26L... Left operation lever 26R... Right operation lever 28... Discharge pressure sensor 29... Operation sensor 30... Controller 31... Proportional valve 40... Display device 50... Flying body 55... Pole 60... Control valve 70: Object detection device 70A: Attachment camera 70B: Rear camera 70D: Camera 70F: Front camera 70L: Left camera 70P: Fixed point camera 70R: Right camera 85: Positioning device 100: Shovel 171 to 176: Control valves 200: Support device 300: Management device CD1: Pilot line S1: Boom angle sensor S2: Arm angle sensor S3: Bucket angle sensor S4: Machine body inclination sensor S5: Turning angular velocity sensor SYS: Control system

Claims

1. A lower running body; An upper rotating body mounted on the lower traveling body; An attachment mounted on the upper rotating body; an actuator for moving the attachment; The actuator is configured to suppress movement at a site where a predetermined task is performed, The predetermined task is a task performed by moving the attachment in a situation where a worker works in the vicinity of the attachment. Shovel.

2. The predetermined work is a deep excavation work or a crane work, The shovel according to claim 1.

3. The actuator is configured to suppress movement when an object present around the end attachment is detected. The shovel according to claim 1.

4. determining whether or not the user is present at a site where the predetermined work is to be performed based on the information acquired by the information acquisition device, and suppressing the movement of the actuator when it is determined that the user is present at a site where the predetermined work is to be performed; The shovel according to claim 1.

5. determining whether or not the user is present at a site where the predetermined work is to be performed based on position information acquired by a positioning device serving as the information acquisition device, and suppressing movement of the actuator when it is determined that the user is present at the site where the predetermined work is to be performed. The shovel according to claim 4.

6. determining whether or not the person is present at a site where the predetermined work is to be performed based on an image acquired by an imaging device serving as the information acquisition device, and suppressing movement of the actuator when it is determined that the person is present at the site where the predetermined work is to be performed. The shovel according to claim 4.

7. The end attachment is configured to detect an object present around the end attachment based on an image acquired by an imaging device attached to the attachment, The image acquired by the imaging device attached to the attachment includes an image of the end attachment. The shovel according to claim 3.

8. When a worker is detected around the end attachment, the attention of at least one of the operator and the worker is called. The shovel according to claim 3.

9. the actuator is a hydraulic actuator; suppressing the movement of the hydraulic actuator by controlling the movement of at least one of a hydraulic pump that supplies hydraulic oil to the hydraulic actuator, a control valve that controls the flow rate of hydraulic oil flowing into the hydraulic actuator, and a power source that drives the hydraulic pump; The shovel according to claim 1.

10. suppressing the movement of the actuator without limiting the maximum value of the operating speed of the actuator at the site where the predetermined work is performed; The shovel according to claim 1.

11. suppressing the movement of the actuator by stopping the actuator, reducing the maximum operating speed of the actuator, reducing the relief pressure of a relief valve provided in a center bypass pipeline, reducing the output power of a power source, or switching an operation mode of the shovel; The shovel according to claim 1.

12. A control system for a shovel including a lower traveling body, an upper rotating body mounted on the lower traveling body, an attachment mounted on the upper rotating body, and an actuator that moves the attachment, The actuator is configured to suppress movement when an object is detected around the end attachment at a site where a predetermined operation is performed, The predetermined task is a task performed by moving the attachment in a situation where a worker works in the vicinity of the attachment. Excavator control system.

13. A remote control system for a shovel comprising: a lower traveling body; an upper rotating body mounted on the lower traveling body; an attachment mounted on the upper rotating body; and an actuator for moving the attachment, The actuator is configured to suppress movement when an object is detected around the end attachment at a site where a predetermined operation is performed, The predetermined task is a task performed by moving the attachment in a situation where a worker works in the vicinity of the attachment. Remote control system for excavators.