JP2021188432A - Shovel - Google Patents

Abstract

To provide a technology that can further improve the stability of a shovel during the discharge operation of an attachment.SOLUTION: A shovel in accordance with an embodiment of the present disclosure is provided with a lower traveling body, an upper revolving body that is mounted on the lower traveling body so that it can revolve freely, an attachment including a boom attached to the upper revolving body, an arm attached to a tip of the boom, and a bucket attached to a tip of the arm, and a boom cylinder that drives the boom. When the attachment performs a discharging operation to discharge the contents of the bucket to the outside, hydraulic fluid is supplied to the boom cylinder regardless of the operation state of the boom.SELECTED DRAWING: Figure 7

Description

This disclosure relates to excavators.

For example, there is known a technique for relieving the hydraulic oil in the oil chamber on the bottom side of the boom cylinder when the attachment that discharges the contained matter such as earth and sand stored in the bucket to the outside (hereinafter referred to as “draining operation”) is operated. (See Patent Document 1).

According to such a technique, during the discharge operation of the attachment, the pressure in the oil chamber on the bottom side of the boom cylinder, which rises due to the unswinging force of the force in the extension direction acting on the boom cylinder, is released and acts on the airframe. The overturning moment can be suppressed.

Japanese Unexamined Patent Publication No. 2019-7175

However, with the above technology, although it is possible to suppress the dynamically generated overturning moment acting on the airframe, the boom moves in the downward direction, so that the entire center of gravity of the attachment moves in the direction away from the airframe. Static stability may be reduced.

Therefore, in view of the above problems, it is an object of the present invention to provide a technique capable of further improving the stability of the excavator during the discharge operation of the attachment.

In order to achieve the above object, in one embodiment of the present disclosure,
With the lower running body,
The upper swivel body that is freely mounted on the lower traveling body and the upper swivel body
An attachment including a boom attached to the upper swing body, an arm attached to the tip of the boom, and a bucket attached to the tip of the arm.
With a boom cylinder for driving the boom,
When the attachment performs a discharge operation for discharging the contents of the bucket to the outside, hydraulic oil is supplied to the boom cylinder regardless of the operating state of the boom.
A shovel is provided.

According to the above-described embodiment, it is possible to provide a technique capable of further improving the stability of the excavator during the discharge operation of the attachment.

It is a schematic diagram which shows an example of the excavator management system. It is a figure which shows an example of the structure of a shovel management system. It is a figure which shows another example of the configuration of a shovel management system. It is a figure which shows the behavior change of the excavator at the time of the discharge operation of the excavator (attachment). It is a figure which shows the force and the moment which act on each of a boom cylinder and a machine body at the time of the excavator (attachment) discharge operation. It is a figure which shows the force and the moment which act on each of a boom cylinder and a machine body at the time of the excavator (attachment) discharge operation. It is a figure which shows the 1st example of the structure about the behavior stabilization at the time of discharging operation of a shovel. It is a figure which shows the 2nd example of the structure about the behavior stabilization at the time of a shovel discharge operation. It is a flowchart which shows the 1st example of the control process about the behavior stabilization at the time of a shovel discharge operation schematically. It is a flowchart which shows the 2nd example of the control process about the behavior stabilization at the time of a shovel discharge operation schematically. It is a flowchart which shows the 3rd example of the control process about the behavior stabilization at the time of a shovel discharge operation schematically.

Hereinafter, embodiments will be described with reference to the drawings.

[Overview of excavator management system]
First, the outline of the excavator management system SYS according to the present embodiment will be described with reference to FIG.

FIG. 1 is a schematic view showing an example of the excavator management system SYS according to the present embodiment.

As shown in FIG. 1, the excavator management system SYS includes an excavator 100 and a management device 200.

The excavator 100 included in the excavator management system SYS may be one or a plurality of excavators 100. Similarly, the excavator management system SYS may have a plurality of management devices 200. That is, the plurality of management devices 200 may carry out the processing related to the excavator management system SYS in a distributed manner. For example, each of the plurality of management devices 200 communicates with each other with a part of the excavators 100 in charge of the plurality of excavators 100, and executes a process for the part of the excavators 100. good.

The excavator management system SYS collects information from the excavator 100 in the management device 200, for example, and monitors various states of the excavator 100 (for example, the presence or absence of abnormalities in various devices mounted on the excavator 100).

Further, the excavator management system SYS may support the remote control of the excavator 100 in the management device 200, for example.

<Overview of excavator>
As shown in FIG. 1, the excavator 100 according to the present embodiment includes a lower traveling body 1, an upper swivel body 3 mounted on the lower traveling body 1 so as to be swivelable via a swivel mechanism 2, a boom 4, and an arm 5. , And an attachment including a bucket 6 and a cabin 10 on which the operator is boarded. Hereinafter, the front of the excavator 100 has an attachment to the upper swivel body 3 when the shovel 100 is viewed from directly above along the swivel axis of the upper swivel body 3 in a plan view (hereinafter, simply referred to as “planar view”). Corresponds to the direction of extension. Further, the left and right sides of the excavator 100 correspond to the left and right sides as seen from the operator in the cabin 10, respectively.

The lower traveling body 1 includes, for example, a pair of left and right crawlers. The lower traveling body 1 travels the excavator 100 by hydraulically driving each crawler with the traveling hydraulic motor 1ML on the left side and the traveling hydraulic motor 1MR (see FIG. 2) on the right side.

The upper swivel body 3 swivels with respect to the lower traveling body 1 by hydraulically driving the swivel mechanism 2 with the swivel hydraulic motor 2A.

The boom 4 is vertically attached to the center of the front portion of the upper swing body 3, the arm 5 is attached to the tip of the boom 4 so as to be vertically rotatable, and the bucket 6 is vertically rotated to the tip of the arm 5. Can be installed.

The bucket 6 is an example of an end attachment. The bucket 6 is used, for example, for excavation work and the like. Further, another end attachment may be attached to the tip of the arm 5 instead of the bucket 6 depending on the work content and the like. The other end attachment may be, for example, another type of bucket, such as a slope bucket, a dredging bucket, or the like. Further, the other end attachment may be an end attachment of a type other than a bucket such as a stirrer or a breaker.

The boom 4, arm 5, and bucket 6 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 as hydraulic actuators, respectively.

The cabin 10 is a cockpit on which the operator is boarded, and is mounted on the front left side of the upper swivel body 3.

The excavator 100 is equipped with a communication device 60 and can communicate with the management device 200 through a predetermined communication line NW (Network). As a result, the excavator 100 can transmit (upload) various information to the management device 200, and can receive various signals (for example, information signals and control signals) from the management device 200. The communication line NW includes, for example, a wide area network (WAN). The wide area network may include, for example, a mobile communication network having a base station as an end. Further, the wide area network may include, for example, a satellite communication network that uses a communication satellite in the sky above the excavator 100. Further, the wide area network may include, for example, an Internet network. Further, the communication line NW may include, for example, a local network (LAN: Local Area Network) of the facility where the management device 200 is installed. The local network may be a wireless line, a wired line, or a line including both of them. Further, the communication line NW may include, for example, a short-range communication line based on a predetermined wireless communication method such as WiFi or Bluetooth (registered trademark).

The excavator 100 operates an actuator (for example, a hydraulic actuator) in response to an operation of an operator boarding the cabin 10, and operates elements such as a lower traveling body 1, an upper swivel body 3, a boom 4, an arm 5, and a bucket 6. (Hereinafter, "driven element") is driven.

Further, the excavator 100 may be configured to be operable instead of being operable by the operator of the cabin 10, or in addition, to be remotely controlled (remote operation) from the outside of the excavator 100. When the excavator 100 is remotely controlled, the inside of the cabin 10 may be unmanned. Hereinafter, the description will proceed on the premise that the operation of the operator includes at least one of the operation of the cabin 10 with respect to the operation device 26 and the remote operation by an external operator.

The remote control includes, for example, an embodiment in which the excavator 100 is operated by an input from a user (operator) regarding the actuator of the excavator 100 performed by a predetermined external device (for example, the management device 200). In this case, the excavator 100 transmits, for example, image information around the excavator 100 (hereinafter, “peripheral image”) based on the output of the image pickup apparatus S6 described later to an external device, and the image information is displayed on the external device. It may be displayed on the device (hereinafter, "display device for remote operation"). Further, various information images (information screens) displayed on the output device 50 in the cabin 10 of the excavator 100 may be similarly displayed on the remote control display device of the external device. As a result, the operator of the external device remotely controls the excavator 100 while checking the display contents such as the surrounding image showing the surrounding state of the excavator 100 and various information images displayed on the remote control display device, for example. be able to. Further, the excavator 100 operates the actuator in response to the remote control signal indicating the content of the remote control received from the external device, and the lower traveling body 1, the upper turning body 3, the boom 4, the arm 5, and the shovel 100 operate the actuator. A driven element such as a bucket 6 may be driven.

Further, the remote control may include, for example, an embodiment in which the excavator 100 is operated by an external voice input or a gesture input to the excavator 100 by a person (for example, a worker) around the excavator 100. Specifically, the excavator 100 is performed by a voice or a worker spoken by a surrounding worker or the like through an image pickup device or a voice input device (for example, a microphone) mounted on the shovel 100 (own machine). Recognize gestures, etc. Then, the excavator 100 operates an actuator according to the recognized voice, gesture, or the like to drive driven elements such as the lower traveling body 1, the upper turning body 3, the boom 4, the arm 5, and the bucket 6. It's okay.

Further, the excavator 100 may automatically operate the actuator regardless of the contents of the operator's operation. As a result, the excavator 100 automatically operates at least a part of the driven elements such as the lower traveling body 1, the upper turning body 3, the boom 4, the arm 5, and the bucket 6 (so-called "automatic driving function" or "automatic driving function" or ". Machine control function ") is realized.

The automatic operation function is a function (so-called "semi-automatic luck function") in which a driven element (actuator) other than the driven element (actuator) to be operated is automatically operated in response to an operator's operation on the operation device 26 or a remote control. Alternatively, "operation support type machine control function") may be included. In addition, the automatic operation function is a function that automatically operates at least a part of a plurality of driven elements (hydraulic actuators) on the premise that there is no operation or remote control of the operator's operation device 26 (so-called "fully automatic operation function"). Alternatively, "fully automatic machine control function") may be included. When the fully automatic driving function is enabled in the excavator 100, the inside of the cabin 10 may be unmanned. Further, the semi-automatic operation function, the fully automatic operation function, and the like may include an embodiment in which the operation content of the driven element (actuator) to be automatically operated is automatically determined according to a predetermined rule. Further, for the semi-automatic operation function, the fully automatic operation function, etc., the excavator 100 autonomously makes various judgments, and the driven element (hydraulic actuator) to be automatically operated is autonomously operated according to the judgment results. A mode in which the content is determined (so-called “autonomous driving function”) may be included.

<Overview of management device>
The management device 200 manages the excavator 100, such as the state of the excavator 100 and the work of the excavator 100.

The management device 200 may be, for example, a cloud server installed in a management center or the like outside the work site where the excavator 100 works. Further, the management device 200 is, for example, an edge server arranged in a work site where the excavator 100 works, or in a place relatively close to the work site (for example, a telecommunications carrier's station building or a base station). You may. Further, the management device 200 may be a stationary terminal device or a portable terminal device (portable terminal) arranged in a management office or the like in the work site of the excavator 100. The stationary terminal device may include, for example, a desktop computer terminal. Further, the portable terminal device may include, for example, a smartphone, a tablet terminal, a laptop computer terminal, or the like.

The management device 200 has, for example, a communication device 220 (see FIGS. 2 and 3), and as described above, communicates with the excavator 100 through the communication line NW. As a result, the management device 200 can receive various information uploaded from the excavator 100 and transmit various signals to the excavator 100. Therefore, the user of the management device 200 can confirm various information about the excavator 100 through the output device 240 (see FIGS. 2 and 3). Further, the management device 200 can, for example, transmit an information signal to the excavator 100 to provide information necessary for work, or transmit a control signal to control the excavator 100. The users of the management device 200 include, for example, the owner of the excavator 100, the manager of the excavator 100, the engineer of the manufacturer of the excavator 100, the operator of the excavator 100, the manager, the supervisor, and the operator of the work site of the excavator 100. May be included.

Further, the management device 200 may be configured to be able to support the remote control of the excavator 100. For example, the management device 200 is a remote control display that displays an input device for the operator to perform remote control (hereinafter, “remote control device” for convenience), image information (surrounding image) around the shovel 100, and the like. You may have a device. The signal input from the remote control device is transmitted to the excavator 100 as a remote control signal. As a result, the user (operator) of the management device 200 can remotely control the excavator 100 by using the remote control device while checking the surroundings of the excavator 100 on the remote control display device.

[Excavator management system configuration]
Next, a specific configuration of the excavator management system SYS will be described with reference to FIGS. 2 and 3 in addition to FIG.

2 and 3 are block diagrams showing an example and other examples of the configuration of the excavator management system SYS according to the present embodiment. In FIGS. 2 and 3, the path through which mechanical power is transmitted is a double line, the path through which high-pressure hydraulic oil for driving a hydraulic actuator flows is a solid line, the path through which pilot pressure is transmitted is a broken line, and an electric signal is transmitted. The routes are indicated by dotted lines. 2 and 3 differ from each other only in the configuration of the excavator 100 and the excavator 100 of the management device 200.

<Composition of excavator>
The excavator 100 includes a hydraulic drive system for hydraulically driving a driven element, an operation system for operating the driven element, a user interface system for exchanging information with a user, a communication system for communicating with the outside, a control system for various controls, and the like. Includes each component of.

<< Hydraulic drive system >>
As shown in FIGS. 2 and 3, the hydraulic drive system of the excavator 100 according to the present embodiment has the lower traveling body 1 (left and right crawlers), the upper turning body 3, the boom 4, the arm 5, and the bucket as described above. It includes a hydraulic actuator that hydraulically drives each of the driven elements such as 6. The hydraulic actuator includes a traveling hydraulic motor 1ML, 1MR, a turning hydraulic motor 2A, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, and the like. Further, the hydraulic drive system of the excavator 100 according to the present embodiment includes an engine 11, a regulator 13, a main pump 14, and a control valve 17.

The engine 11 is the main power source in the hydraulic drive system. The engine 11 is, for example, a diesel engine that uses light oil as fuel. The engine 11 is mounted on the rear portion of the upper swing body 3, for example. The engine 11 rotates constantly at a preset target rotation speed under direct or indirect control by the controller 30, which will be described later, to drive the main pump 14 and the pilot pump 15.

The regulator 13 controls (adjusts) the discharge amount of the main pump 14 under the control of the controller 30. For example, the regulator 13 adjusts the angle of the swash plate of the main pump 14 (hereinafter, “tilt angle”) in response to a control command from the controller 30.

The main pump 14 supplies hydraulic oil to the control valve 17 through a high pressure hydraulic line. The main pump 14 is mounted on the rear portion of the upper swing body 3, for example, like the engine 11. The main pump 14 is driven by the engine 11 as described above. The main pump 14 is, for example, a variable displacement hydraulic pump, and as described above, the stroke length of the piston is adjusted by adjusting the tilt angle of the swash plate by the regulator 13 under the control of the controller 30, and the discharge is performed. The flow rate (discharge pressure) is controlled.

The control valve 17 is a hydraulic control device that controls the hydraulic actuator in response to the contents of the operation or remote control of the operator to the operation device 26, or the operation command regarding the automatic operation function output from the controller 30. The control valve 17 is mounted on the central portion of the upper swing body 3, for example. As described above, the control valve 17 is connected to the main pump 14 via the high-pressure hydraulic line, and the hydraulic oil supplied from the main pump 14 is output from the operating state of the operating device 26 or the operation command from the controller 30. It is selectively supplied to hydraulic actuators (running hydraulic motor 1ML, 1MR, swivel hydraulic motor 2A, boom cylinder 7, arm cylinder 8, bucket cylinder 9, etc.). Specifically, the control valve 17 includes a plurality of control valves (also referred to as "direction switching valves") 17A to 17F that control the flow rate and the flow direction of the hydraulic oil supplied from the main pump 14 to each of the hydraulic actuators. .. Hereinafter, the control valves 17A to 17F may be comprehensively referred to, or any one of the control valves 17A to 17F may be individually referred to as "control valve 17X".

The control valve 17A is configured to supply hydraulic oil to the traveling hydraulic motor 1ML, discharge the hydraulic oil from the traveling hydraulic motor, and return the hydraulic oil to the tank. Thereby, the control valve 17B can drive the traveling hydraulic motor 1ML according to the pilot pressure supplied from the hydraulic control valve 31 corresponding to the operation of the traveling hydraulic motor 1MR (that is, the operation of the left crawler). ..

The control valve 17B is configured to supply hydraulic oil to the traveling hydraulic motor 1MR, discharge the hydraulic oil from the traveling hydraulic motor, and return the hydraulic oil to the tank. Thereby, the control valve 17B can drive the traveling hydraulic motor 1MR according to the pilot pressure supplied from the hydraulic control valve 31 corresponding to the operation of the traveling hydraulic motor 1MR (that is, the operation of the crawler on the right side). ..

The control valve 17C is configured to supply hydraulic oil to the swing hydraulic motor 2A, discharge the hydraulic oil from the swing hydraulic motor 2A, and return the hydraulic oil to the tank. As a result, the control valve 17C can drive the swing hydraulic motor 2A according to the pilot pressure supplied from the hydraulic control valve 31 corresponding to the operation of the swing hydraulic motor 2A (that is, the operation of the upper swing body 3). can.

The control valve 17D is configured to supply hydraulic oil to the boom cylinder 7 and discharge the hydraulic oil from the boom cylinder 7 so that the hydraulic oil can be returned to the tank. Thereby, the control valve 17D can drive the boom cylinder 7 according to the pilot pressure supplied from the hydraulic control valve 31 corresponding to the operation of the boom cylinder 7 (that is, the operation of the boom 4).

The control valve 17E is configured to supply hydraulic oil to the arm cylinder 8 and discharge the hydraulic oil from the arm cylinder 8 so that the hydraulic oil can be returned to the tank. Thereby, the control valve 17E can drive the arm cylinder 8 according to the pilot pressure supplied from the hydraulic control valve 31 corresponding to the operation of the arm cylinder 8 (that is, the operation of the arm 5).

The control valve 17F is configured to supply hydraulic oil to the bucket cylinder 9 and discharge the hydraulic oil from the bucket cylinder 9 so that the hydraulic oil can be returned to the tank. As a result, the control valve 17F can drive the bucket cylinder 9 according to the pilot pressure supplied from the hydraulic control valve 31 corresponding to the operation of the bucket cylinder 9 (that is, the operation of the bucket 6).

The control valve 17X is, for example, a spool valve having two ports P1 and P2 to which pilot pressure is supplied (see, for example, control valve 17D in FIGS. 7 and 8). The control valve 17X has a built-in spool that can move in the axial direction, and the spool is urged from spring members provided at both ends thereof toward the opposite end so as to be balanced at a predetermined neutral position. There is.

When hydraulic oil is supplied to the port P1 of the control valve 17X, the pressure (pilot pressure) acts on one end in the axial direction of the spool, and the spool moves to the other end side in the axial direction with respect to the neutral position. As a result, the control valve 17X communicates the path for supplying hydraulic oil to one of the two hydraulic oil supply / discharge ports of the hydraulic actuator and discharging the hydraulic oil from the other as the spool moves, so that the hydraulic actuator can be used. It can be driven in one direction.

On the other hand, when hydraulic oil is supplied to the port P2 of the control valve 17X, the pressure (pilot pressure) acts on the other end of the spool in the axial direction, and the spool moves to one end side in the axial direction with reference to the neutral position. .. As a result, the control valve 17X communicates the hydraulic actuator with a path for supplying hydraulic oil to the other of the two hydraulic oil supply / discharge ports of the hydraulic actuator and discharging the hydraulic oil from one of the two hydraulic actuator ports as the spool moves. It can be driven in other directions.

<< Operation system >>
As shown in FIGS. 2 and 3, the operation system of the excavator 100 according to the present embodiment includes a pilot pump 15, a gate lock valve 25V, an operation device 26, and a hydraulic control valve 31. Further, as shown in FIG. 2, the operation system of the excavator 100 according to the present embodiment includes a shuttle valve 32 and a hydraulic control valve 33 when the operation device 26 is a hydraulic pilot type.

The pilot pump 15 supplies pilot pressure to various hydraulic devices via the pilot line 25. The pilot pump 15 is mounted on the rear portion of the upper swing body 3, for example, like the engine 11. The pilot pump 15 is, for example, a fixed-capacity hydraulic pump, and is driven by the engine 11 as described above.

The gate lock valve 25V is provided in the pilot line 25 upstream of all various hydraulic devices supplied with hydraulic oil from the pilot pump 15. The gate lock valve 25V switches communication and disconnection (non-communication) of the pilot line 25 by ON / OFF of the limit switch linked with the operation of the gate lock lever inside the cabin 10. Specifically, when the gate lock lever is raised, that is, when the cockpit is open, the limit switch is turned off, and the solenoid of the gate lock valve 25V receives a voltage from a power source (for example, a battery). No application is applied, and the gate lock valve 25V is in a non-communication state. Therefore, the pilot line 25 is cut off, and hydraulic oil is not supplied to various hydraulic devices including the hydraulic control valve 31. On the other hand, when the gate lock lever is lowered, that is, when the cockpit is closed, the limit switch is turned on, a voltage is applied to the solenoid of the gate lock valve 25V from the power supply, and the gate lock valve 25V communicates. Become a state. Therefore, the pilot line 25 communicates with each other, and hydraulic oil is supplied to various hydraulic devices including the hydraulic control valve 31.

The operating device 26 is provided near the cockpit of the cabin 10 and is used by the operator to operate various driven elements (lower traveling body 1, upper turning body 3, boom 4, arm 5, bucket 6, etc.). .. In other words, the operating device 26 is a hydraulic actuator in which the operator drives each driven element (that is, a traveling hydraulic motor 1ML, 1MR, a turning hydraulic motor 2A, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, etc.). It is used to perform the operation of. The operating device 26 includes, for example, a lever device for operating each of the boom 4 (boom cylinder 7), the arm 5 (arm cylinder 8), the bucket 6 (bucket cylinder 9), and the upper swing body 3 (swing hydraulic motor 2A). include. Further, the operating device 26 includes, for example, a pedal device or a lever device that operates each of the left and right crawlers (traveling hydraulic motors 1ML, 1MR) of the lower traveling body 1.

For example, as shown in FIG. 2, the operating device 26 is a hydraulic pilot type. Specifically, the operating device 26 uses the hydraulic oil supplied from the pilot pump 15 through the pilot line 25 and the pilot line 25A branched from the pilot line 25 to apply a pilot pressure according to the operation content to the pilot on the secondary side. Output to line 27A. The pilot line 27A is connected to one inlet port of the shuttle valve 32 and is connected to the control valve 17 via a pilot line 27 connected to the outlet port of the shuttle valve 32. As a result, the pilot pressure can be input to the control valve 17 via the shuttle valve 32 according to the operation content of the various driven elements (hydraulic actuators) in the operating device 26. Therefore, the control valve 17 can drive each hydraulic actuator according to the operation content for the operating device 26 such as the operator.

Further, for example, as shown in FIG. 3, the operating device 26 is an electric type. Specifically, the operation device 26 outputs an electric signal (hereinafter, “operation signal”) according to the operation content, and the operation signal is taken into the controller 30. Then, the controller 30 outputs a control command according to the content of the operation signal, that is, a control signal according to the operation content to the operation device 26 to the hydraulic control valve 31. As a result, the pilot pressure corresponding to the operation content of the operation device 26 is input from the hydraulic control valve 31 to the control valve 17, and the control valve 17 drives each hydraulic actuator according to the operation content of the operation device 26. Can be done.

Further, the control valve 17X (direction switching valve) built in the control valve 17 for driving each hydraulic actuator may be an electromagnetic solenoid type. In this case, the operation signal output from the operation device 26 may be directly input to the control valve 17, that is, the electromagnetic solenoid type control valve 17X.

The hydraulic control valve 31 is provided for each driven element (hydraulic actuator) to be operated by the operating device 26. That is, the hydraulic control valve 31 is, for example, a crawler on the left side (running hydraulic motor 1ML), a crawler on the right side (running hydraulic motor 1MR), an upper swivel body 3 (swivel hydraulic motor 2A), a boom 4 (boom cylinder 7), and an arm. It is provided for each of 5 (arm cylinder 8) and bucket 6 (bucket cylinder 9). The hydraulic control valve 31 is provided, for example, in the pilot line 25B between the pilot pump 15 and the control valve 17, and is configured so that the flow path area (that is, the cross-sectional area through which the hydraulic oil can flow) can be changed. good. As a result, the hydraulic control valve 31 can output a predetermined pilot pressure to the pilot line 27B on the secondary side by utilizing the hydraulic oil of the pilot pump 15 supplied through the pilot line 25B. Therefore, as shown in FIG. 2, the hydraulic control valve 31 indirectly controls a predetermined pilot pressure according to the control signal from the controller 30 through the shuttle valve 32 between the pilot line 27B and the pilot line 27. It can act on 17. Further, as shown in FIG. 3, the hydraulic control valve 31 can directly apply a predetermined pilot pressure according to the control signal from the controller 30 to the control valve 17 through the pilot line 27B and the pilot line 27. can. Therefore, the controller 30 can supply the pilot pressure according to the operation content of the electric operation device 26 from the hydraulic control valve 31 to the control valve 17, and can realize the operation of the excavator 100 based on the operation of the operator.

Further, the controller 30 may control, for example, the hydraulic control valve 31 to realize an automatic operation function. Specifically, the controller 30 outputs a control signal corresponding to an operation command related to the automatic operation function to the hydraulic control valve 31 regardless of whether or not the operation device 26 is operated. As a result, the controller 30 can supply the pilot pressure corresponding to the operation command related to the automatic operation function from the hydraulic control valve 31 to the control valve 17, and can realize the operation of the excavator 100 based on the automatic operation function.

Further, the controller 30 may control, for example, the hydraulic control valve 31 to realize remote control of the excavator 100. Specifically, the controller 30 outputs a control signal corresponding to the content of the remote control specified by the remote control signal received from the management device 200 to the hydraulic control valve 31 by the communication device 60 described later. As a result, the controller 30 can supply the pilot pressure corresponding to the content of the remote control from the hydraulic control valve 31 to the control valve 17, and can realize the operation of the excavator 100 based on the remote control of the operator.

As shown in FIG. 2, the shuttle valve 32 has two inlet ports and one outlet port, and the hydraulic oil having the higher pilot pressure of the pilot pressures input to the two inlet ports is discharged to the outlet port. To output to. The shuttle valve 32 is provided for each driven element (hydraulic actuator) to be operated by the operating device 26. That is, the shuttle valve 32 is, for example, a left crawler (running hydraulic motor 1ML), a right crawler (running hydraulic motor 1MR), an upper swing body 3 (swing hydraulic motor 2A), a boom 4 (boom cylinder 7), and an arm 5. It is provided for each (arm cylinder 8) and bucket 6 (bucket cylinder 9). One of the two inlet ports of the shuttle valve 32 is connected to the pilot line 27A on the secondary side of the operating device 26 (specifically, the lever device or pedal device described above included in the operating device 26), and the other It is connected to the pilot line 27B on the secondary side of the hydraulic control valve 31. The outlet port of the shuttle valve 32 is connected through the pilot line 27 to the pilot port of the corresponding control valve of the control valve 17. The corresponding control valve is a control valve that drives a hydraulic actuator that is an operation target of the above-mentioned lever device or pedal device connected to one inlet port of the shuttle valve 32. Therefore, these shuttle valves 32 correspond to the higher of the pilot pressure of the pilot line 27A on the secondary side of the operating device 26 and the pilot pressure of the pilot line 27B on the secondary side of the hydraulic control valve 31, respectively. It can act on the pilot port of the control valve. That is, the controller 30 controls the corresponding control valve regardless of the operator's operation on the operating device 26 by outputting the pilot pressure higher than the pilot pressure on the secondary side of the operating device 26 from the hydraulic control valve 31. be able to. Therefore, the controller 30 can control the operation of the driven element (lower traveling body 1, upper turning body 3, attachment) regardless of the operating state of the operator with respect to the operating device 26, and can realize the automatic driving function.

As shown in FIG. 2, the hydraulic control valve 33 is provided on the pilot line 27A connecting the operating device 26 and the shuttle valve 32. The hydraulic control valve 33 is configured so that the flow path area thereof can be changed, for example. The hydraulic control valve 33 operates in response to a control signal input from the controller 30. As a result, the controller 30 can forcibly reduce the pilot pressure output from the operating device 26 when the operating device 26 is operated by the operator. Therefore, the controller 30 can forcibly suppress or stop the operation of the hydraulic actuator corresponding to the operation of the operating device 26 even when the operating device 26 is being operated. Further, for example, even when the operating device 26 is operated, the controller 30 reduces the pilot pressure output from the operating device 26 to be lower than the pilot pressure output from the hydraulic control valve 31. Can be done. Therefore, the controller 30 controls the hydraulic control valve 31 and the hydraulic control valve 33 to, for example, apply a desired pilot pressure to the pilot port of the control valve in the control valve 17 regardless of the operation content of the operating device 26. It can work reliably. Therefore, for example, the controller 30 can more appropriately realize the automatic operation function and the remote control function of the excavator 100 by controlling the hydraulic control valve 33 in addition to the hydraulic control valve 31.

<< User interface system >>
As shown in FIGS. 2 and 3, the user interface system of the excavator 100 according to the present embodiment includes an operation device 26, an output device 50, and an input device 52.

The output device 50 outputs various information to the user (operator) of the excavator 100 inside the cabin 10.

For example, the output device 50 is provided in a place in the cabin 10 that is easily visible to a seated operator, and includes an indoor lighting device, a display device, and the like that output various information by a visual method. The lighting device is, for example, a warning light or the like. The display device is, for example, a liquid crystal display or an organic EL (Electroluminescence) display.

Further, for example, the output device 50 includes a sound output device that outputs various information by an auditory method. The sound output device includes, for example, a buzzer, a speaker, and the like.

The input device 52 is provided in a range close to the seated operator in the cabin 10, receives various inputs by the operator, and signals corresponding to the received inputs are taken into the controller 30.

For example, the input device 52 is an operation input device that accepts operation inputs. The operation input device includes a touch panel mounted on the display device, a touch pad installed around the display device, a button switch, a lever, a toggle, a knob switch provided on the operation device 26 (lever device), and the like.

Further, for example, the input device 52 may be a voice input device that accepts the voice input of the operator. The voice input device includes, for example, a microphone.

Further, for example, the input device 52 may be a gesture input device that accepts the gesture input of the operator. The gesture input device includes, for example, an image pickup device (indoor camera) installed in the cabin 10.

<< Communication system >>
As shown in FIGS. 2 and 3, the communication system of the excavator 100 according to the present embodiment includes the communication device 60.

The communication device 60 is connected to the communication line NW and communicates with a device (for example, a management device 200) provided separately from the excavator 100. The device provided separately from the excavator 100 may include a device outside the excavator 100 and a portable terminal device brought into the cabin 10 by the user of the excavator 100. Communication device 60 may comprise, for example, a mobile communication module that conforms to 4G (4 ^th Generation) and 5G (5 ^th Generation) standard such. Further, the communication device 60 may include, for example, a satellite communication module. Further, the communication device 60 may include, for example, a WiFi communication module, a Bluetooth communication module, or the like.

<< Control system >>
As shown in FIGS. 2 and 3, the control system of the excavator 100 according to the present embodiment includes the controller 30. Further, the control system of the excavator 100 according to the present embodiment includes a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body tilt sensor S4, a turning state sensor S5, an image pickup device S6, and a boom. It includes a cylinder pressure sensor S7, an arm cylinder pressure sensor S8, and a bucket cylinder pressure sensor S9. Further, as shown in FIG. 2, the control system of the shovel 100 according to the present embodiment includes an operating pressure sensor 29 when the operating device 26 is a hydraulic pilot type.

The controller 30 performs various controls related to the excavator 100. The function of the controller 30 may be realized by any hardware, or a combination of any hardware and software. For example, the controller 30 is a computer including a CPU (Central Processing Unit), a memory device such as a RAM (Random Access Memory), a non-volatile auxiliary storage device such as a ROM (Read Only Memory), an interface device for various input / output, and the like. Is mainly composed of. The controller 30 realizes various functions by, for example, loading a program installed in the auxiliary storage device into the memory device and executing the program on the CPU.

The controller 30 controls the operation of the hydraulic actuator (driven element) of the excavator 100, for example, with the hydraulic control valve 31 as the control target.

Specifically, the controller 30 may control the operation of the hydraulic actuator (driven element) of the excavator 100 based on the operation of the operating device 26 with the hydraulic control valve 31 as the control target.

Further, the controller 30 may control the remote control of the hydraulic actuator (driven element) of the excavator 100 with the hydraulic control valve 31 as the control target. That is, the operation of the hydraulic actuator (driven element) of the excavator 100 may include remote control of the hydraulic actuator from the outside of the excavator 100.

Further, the controller 30 may control the automatic operation function of the shovel 100 with the hydraulic control valve 31 as the control target. That is, the operation of the hydraulic actuator of the excavator 100 may include an operation command of the hydraulic actuator of the excavator 100, which is output based on the automatic operation function.

Further, the controller 30 controls, for example, the stabilization of the behavior of the excavator 100 (hereinafter, “behavior stabilization”). The controller 30 includes a determination unit 301 and a stabilization control unit 302 as functional units related to stabilizing the behavior of the excavator 100.

A part of the function of the controller 30 may be realized by another controller (control device). That is, the function of the controller 30 may be realized in a distributed manner by a plurality of controllers.

As shown in FIG. 2, the operating pressure sensor 29 operates the pilot pressure on the secondary side (pilot line 27A) of the hydraulic pilot type operating device 26, that is, the operation of each driven element (hydraulic actuator) in the operating device 26. Detects the pilot pressure corresponding to the condition. The pilot pressure detection signal corresponding to the operating state of the lower traveling body 1, the upper swing body 3, the boom 4, the arm 5, the bucket 6 and the like in the operating device 26 by the operating pressure sensor 29 is taken into the controller 30.

The boom angle sensor S1 acquires detection information regarding the posture angle of the boom 4 (hereinafter, “boom angle”) with respect to a predetermined reference (for example, a horizontal plane or a state of both ends of the movable angle range of the boom 4). The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, an angular velocity sensor, a six-axis sensor, an IMU (Inertial Measurement Unit), and the like. Further, the boom angle sensor S1 may include a cylinder sensor capable of detecting the expansion / contraction position of the boom cylinder 7.

The arm angle sensor S2 is a posture angle of the arm 5 with respect to a predetermined reference (for example, a straight line connecting the connecting points at both ends of the boom 4 or a state of both ends of the movable angle range of the arm 5) (hereinafter, “arm angle”). ”) To acquire the detection information. The arm angle sensor S2 may include, for example, a rotary encoder, an acceleration sensor, an angular velocity sensor, a six-axis sensor, an IMU, and the like. Further, the arm angle sensor S2 may include a cylinder sensor capable of detecting the expansion / contraction position of the arm cylinder 8.

The bucket angle sensor S3 has a posture angle of the bucket 6 with respect to a predetermined reference (for example, a straight line connecting the connecting points at both ends of the arm 5 or a state of both ends of the movable angle range of the bucket 6) (hereinafter, “bucket angle”). ”) To acquire the detection information. The bucket angle sensor S3 may include, for example, a rotary encoder, an acceleration sensor, an angular velocity sensor, a six-axis sensor, an IMU, and the like. Further, the bucket angle sensor S3 may include a cylinder sensor capable of detecting the expansion / contraction position of the bucket cylinder 9.

The airframe tilt sensor S4 acquires detection information regarding the tilted state of the airframe including the lower traveling body 1 and the upper swivel body 3. The machine body tilt sensor S4 is mounted on the upper swivel body 3, for example, and acquires detection information regarding the tilt angle in the front-rear direction and the left-right direction of the upper swivel body 3 (hereinafter, “front-back tilt angle” and “left-right tilt angle”). .. The machine body tilt sensor S4 may include, for example, an acceleration sensor (tilt sensor), an angular velocity sensor, a six-axis sensor, an IMU, and the like.

The turning state sensor S5 acquires detection information regarding the turning state of the upper turning body 3. The turning state sensor S5 acquires, for example, detection information regarding the turning angle of the upper turning body 3 with respect to a predetermined reference (for example, a state in which the forward direction of the lower traveling body 1 coincides with the front of the upper turning body 3). The swivel state sensor S5 includes, for example, a potentiometer, a rotary encoder, a resolver, and the like.

Further, it is possible to acquire detection information regarding the posture state of the upper swivel body 3 including not only the tilt angle of the upper swivel body 3 but also the swivel angle by the constituent elements of the body tilt sensor S4 (for example, a six-axis sensor, an IMU, etc.). In this case, the turning state sensor S5 may be omitted.

Further, for example, the excavator 100 may be further equipped with a positioning device capable of positioning the absolute position of the own machine. The positioning device is, for example, a GNSS (Global Navigation Satellite System) sensor. This makes it possible to improve the estimation accuracy of the posture state of the excavator 100.

Further, the sensors S1 to S5 may be omitted. For example, when the information around the excavator 100 acquired by the image pickup device S6, the distance sensor described later, or the like includes information on the positions and shapes of surrounding objects and attachments as seen from the machine body (upper swivel body 3). There is. In this case, for example, the controller 30 can estimate the posture state of the excavator 100 from the information depending on the required accuracy.

The image pickup apparatus S6 captures the surroundings of the excavator 100 and outputs the captured image. The captured image output from the image pickup device S6 is captured by the controller 30.

The image pickup apparatus S6 includes, for example, a monocular camera, a stereo camera, a depth camera, and the like. The image pickup device, and the image pickup device S6, based on the captured image, three-dimensional data (for example, point cloud data or surface data) representing the position and outer shape of an object around the shovel 100 within a predetermined imaging range (angle of view). ) May be obtained.

Instead of or in addition to the image pickup apparatus S6, for example, a distance sensor such as a LIDAR (Light Detecting and Ranging), a millimeter wave radar, an ultrasonic sensor, an infrared sensor, or a distance image sensor may be mounted on the shovel 100. The distance sensor may acquire three-dimensional data representing the position and shape of an object around the excavator 100 within a predetermined detection range.

As shown in FIG. 1, the image pickup apparatus S6 is attached to, for example, the front end of the upper surface of the cabin 10 and acquires a captured image in front of the upper swivel body 3 including the working range of the end attachment (bucket 6). As a result, the controller 30 can recognize the situation in front of the excavator 100 based on the output of the image pickup apparatus S6. Further, the controller 30 determines the position of the shovel 100, the turning state of the upper swivel body 3, and the like based on changes in the position and appearance of objects around the shovel 100 recognized from the output (captured image) of the image pickup device S6. Can be recognized. Further, the imaging range of the imaging device S6 includes a boom 4, an arm 5, and an end attachment (bucket 6), that is, an attachment. Thereby, the controller 30 can recognize the posture state of the attachment (for example, at least one posture angle of the boom 4, the arm 5, and the bucket 6) based on the output of the image pickup apparatus S6. Therefore, when the excavator 100 is remotely controlled, the controller 30 transmits information on the surrounding image and the recognition result based on the image pickup apparatus S6 to the management device 200 and the like, and sends the excavator 100 (own machine) and its surroundings to an external operator. Can provide information about the situation. Further, when the excavator 100 operates with the fully automatic operation function, the control device (for example, the controller 30) related to the fully automatic operation function is a hydraulic actuator while grasping the surrounding situation of the excavator 100, the posture state of the own machine, and the like. Operation commands related to can be output. Further, when the shovel 100 operates with the fully automatic operation function, the controller 30 transmits information on the surrounding image and the recognition result based on the image pickup device S6 to the management device 200 and the like, and a user (monitorer) who monitors the work externally. ) Can provide information on the excavator 100 (own machine) and its surroundings.

Further, the image pickup device S6 may be configured to be able to acquire a captured image regarding at least one of the left side, the right side, and the rear side of the upper swivel body 3. As a result, the controller 30 can recognize not only the front of the excavator 100 but also the left, right, and rear situations of the excavator 100.

The boom cylinder pressure sensor S7 detects the hydraulic pressure (cylinder pressure) of the boom cylinder 7. The boom cylinder pressure sensor S7 includes, for example, a pressure sensor that detects the pressures of the bottom side oil chamber and the rod side oil chamber of the boom cylinder 7. The output (detection signal) of the boom cylinder pressure sensor S7 is taken into the controller 30.

The arm cylinder pressure sensor S8 detects the hydraulic pressure (cylinder pressure) of the arm cylinder 8. The arm cylinder pressure sensor S8 includes, for example, a pressure sensor that detects the pressures of the bottom side oil chamber and the rod side oil chamber of the arm cylinder 8. The output (detection signal) of the arm cylinder pressure sensor S8 is taken into the controller 30.

The bucket cylinder pressure sensor S9 detects the hydraulic pressure (cylinder pressure) of the bucket cylinder 9. The bucket cylinder pressure sensor S9 includes, for example, a pressure sensor that detects the pressures of the bottom side oil chamber and the rod side oil chamber of the bucket cylinder 9. The output (detection signal) of the bucket cylinder pressure sensor S9 is taken into the controller 30.

The determination unit 301 determines the success or failure of a condition for controlling the stability of the behavior of the shovel 100 during the discharge operation of the attachment (hereinafter, “control execution condition”).

The control execution condition includes "the attachment is performing a discharge operation" as an essential condition (hereinafter, "control execution essential condition"). That is, the determination unit 301 determines whether or not the attachment is performing the ejection operation. The discharge operation of the attachment includes at least an operation of opening the bucket 6 from a substantially fully closed state. Further, the attachment ejection operation may include an arm 5 opening operation that is performed together with the bucket 6 opening operation.

The determination unit 301 may determine, for example, whether or not the attachment is performing a discharge operation based on the content of the operation of the attachment (boom 4, arm 5, and bucket 6). As described above, the operation of the attachment may include the operation of the operation device 26, remote control, operation commands based on the automatic operation function, and the like.

Specifically, the determination unit 301 may grasp the operation content of the operation device 26 based on the output of the operation pressure sensor 29 or the operation signal. Further, the determination unit 301 may grasp the content of the remote control based on the remote control signal received from the management device 200 through the communication device 60. Further, the determination unit 301 may acquire an operation command generated by the control device (for example, the controller 30) related to the automatic operation function and grasp the content of the operation command.

Further, the determination unit 301 may grasp the content of the attachment operation based on the actual pilot pressure of the pilot line 27. The actual pilot pressure of the pilot line 27 is detected by the pressure sensor installed in the pilot line 27, and the detection signal is taken into the controller 30.

Further, the determination unit 301 may determine, for example, whether or not the attachment is performing a discharge operation based on a change in the posture state of the attachment.

Specifically, the determination unit 301 may grasp the posture state of the attachment and its change based on the outputs of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3.

Further, the determination unit 301, for example, has a static thrust in the raising direction of the boom 4 (hereinafter, “static boom thrust”) and a dynamic thrust in the raising direction of the boom 4 (hereinafter, “dynamic boom thrust”). ) May be used to determine whether or not the attachment is ejecting. The static boom thrust is the thrust in the raising direction of the boom 4 based on the posture state of the attachment, the center of gravity and its own weight of the attachment, and the external force acting on the attachment, which is derived from the balance equation of the force of the attachment. The dynamic boom thrust is a thrust in the raising direction of the boom 4 based on the actual value of the cylinder pressure of the boom cylinder 7 (detected value of the boom cylinder pressure sensor S7).

Specifically, the determination unit 301 can determine that the attachment is performing the discharge operation when the dynamic boom thrust is significantly reduced with respect to the static boom thrust. When the attachment starts the discharging operation, as described later, the opening operation of the bucket 6 and the arm 5 exerts a force in the extension direction on the boom cylinder 7, and as a result, the pressure in the oil chamber on the bottom side of the boom cylinder 7 is relative. This is because it is greatly reduced (see FIGS. 4 and 5).

Further, the determination unit 301 may determine whether or not the attachment is performing the ejection operation by grasping the operating state of the attachment, for example, based on the captured image of the image pickup device S6.

Further, the control execution condition may include a condition for further limiting the scene in which the control relating to the behavior stabilization of the shovel 100 is executed during the discharge operation of the attachment (hereinafter, “control execution limited condition”). The details of the control execution limited condition will be described later.

The stabilization control unit 302 controls the behavior stabilization of the excavator 100 when it is determined by the determination unit 301 that all the control execution conditions are satisfied. Details of the control related to the stabilization of the behavior of the excavator 100 will be described later.

<Configuration of management device>
As shown in FIG. 2, the management device 200 includes a control device 210, a communication device 220, an input device 230, and an output device 240.

The control device 210 performs various controls related to the management device 200. The function of the control device 210 is realized by arbitrary hardware, an arbitrary combination of hardware and software, and the like. The control device 210 is mainly composed of a computer including, for example, a memory device such as a CPU and RAM, a non-volatile auxiliary storage device such as ROM, and an interface device for various input / output. The control device 210 realizes various functions by executing, for example, a program installed in the auxiliary storage device on the CPU.

For example, the control device 210 may acquire information received from the shovel 100 by the communication device 220, construct a database, or perform predetermined processing to generate processing information.

Further, for example, the control device 210 controls the remote control of the excavator 100. The control device 210 takes in an input signal related to the remote control of the shovel 100 received by the remote control device, and uses the communication device 220 to input an operation input content, that is, a remote control signal representing the content of the remote control of the shovel 100. It may be sent to the excavator 100.

The communication device 220 connects to the communication line NW and communicates with the outside of the management device 200 (for example, the excavator 100).

The input device 230 receives an input from the manager, a worker, or the like of the management device 200, and outputs a signal representing the content of the input (for example, operation input, voice input, gesture input, etc.). The signal representing the content of the input is taken into the control device 210.

The input device 230 may include, for example, a remote control device. As a result, the operator of the management device 200 can remotely control the excavator 100 by using the remote control device.

The output device 240 outputs various information to the user of the management device 200.

The output device 240 includes, for example, a lighting device and a display device that output various information to the user of the management device 200 by a visual method. The lighting device includes, for example, a warning lamp and the like. The display device includes, for example, a liquid crystal display, an organic EL display, and the like. Further, the output device 240 includes a sound output device that outputs various information to the user of the management device 200 by an auditory method. The sound output device includes, for example, a buzzer, a speaker, and the like.

The display device displays various information images related to the management device 200. The display device may include, for example, a display device for remote control, and the display device for remote control may include image information (surrounding image) around the shovel 100 uploaded from the shovel 100 under the control of the control device 210. May be displayed. As a result, the user (operator) of the management device 200 can remotely control the shovel 100 while checking the image information around the shovel 100 displayed on the remote control display device.

[Behavior of the excavator when the attachment is ejected]
Next, the behavior of the excavator 100 during the ejection operation of the attachment will be described with reference to FIGS. 4 to 6.

FIG. 4 is a diagram showing the behavior of the excavator 100 during the discharging operation. Specifically, FIG. 4 shows the cylinder pressure of the oil chamber on the bottom side of the boom cylinder 7 and the pitching angle of the machine body (upper swivel body 3) during the discharge operation of the excavator 100 (around the axis of the upper swivel body 3 in the left-right direction). Includes graphs 410 and 420 showing changes in rotation angle) over time. 5 and 6 are diagrams showing the forces and moments acting on the boom cylinder 7 and the airframe during the discharge operation of discharging the earth and sand DT of the excavator 100 from the bucket 6 to the outside. Specifically, FIG. 5 is a diagram showing forces and moments acting on each of the boom cylinder 7 and the airframe at the start of the discharge operation of the excavator 100 (at time t1 in FIG. 4), and FIG. 6 is a diagram showing the forces and moments acting on each of the boom cylinder 7 and the airframe. It is a figure which shows the force and the moment which act on each of the boom cylinder 7 and the machine body after the start of the discharge operation of the excavator 100 (at the time t2 of FIG. 4).

As shown in FIG. 5, when the attachment ejection operation is started, at least the bucket 6 operates in the opening direction. Therefore, the reaction force acts in the raising direction of the boom 4, and the force F1 in the extending direction acts on the rod of the boom cylinder 7. As a result, as shown in FIG. 4 (graph 410), the cylinder pressure in the oil chamber on the bottom side of the boom cylinder 7 decreases from the time t1 when the attachment discharge operation is started, and the thrust of the boom 4 (dynamic boom thrust). Decreases. Further, a moment M1 of a force in the direction of tilting backward acts on the body of the excavator 100 (the upper swing body 3) by the force F1 in the extension direction acting on the boom cylinder 7.

After the start of the attachment discharge operation, the hydraulic oil inside the boom cylinder 7 functions as a spring element with respect to the displacement of the rod due to the force F1 in the extension direction acting on the boom cylinder 7 at the start. Therefore, as shown in FIG. 6, after the start of the attachment discharge operation, the force F2 acts in the contraction direction by swinging back the force F1 that acts in the extension direction at the start. As a result, as shown in FIG. 4 (graph 410), the cylinder pressure in the oil chamber on the bottom side of the boom cylinder 7 reaches a minimum value between time t1 and time t2 after the start of the attachment discharge operation. Turns up. After that, the cylinder pressure in the oil chamber on the bottom side of the boom cylinder 7 reaches a maximum value to some extent higher than before the start of the attachment discharge operation at time t2, and the thrust of the boom 4 (dynamic boom thrust) is discharged. It rises from before the start of. Further, the moment M2 of the force in the forward tilting direction acts on the body of the excavator 100 (upper swivel body 3) by the force F2 in the contraction direction acting on the boom cylinder 7. As a result, as shown in FIG. 4 (graph 420), the pitching angle of the body of the excavator 100 changes in the forward tilting direction (the direction in which the rear portion is raised).

When the attachment is ejected in this way, the force F1 due to the reaction force of the operation of the bucket 6 and the like and the swinging back force F2 with respect to the force F1 act on the boom cylinder 7. Therefore, the vibration is excited by the force F1 in the extension direction and the force F2 in the opposite contraction direction, and the excavator 100 (airframe) may be vibrated. In addition, the swing-back force F2 becomes excessive, or the vibration amplitude is amplified, and the same contraction direction force as the swing-back force F2 (cylinder pressure in the oil chamber on the bottom side of the boom cylinder 7) becomes excessive. , The excavator 100 may fall forward. Therefore, in the present embodiment, the controller 30 controls the behavior stabilization of the excavator 100 during the ejection operation of the attachment, specifically, the control of suppressing the dynamic stability deterioration of the excavator 100 such as vibration and overturning. conduct.

[Method of stabilizing the behavior of the excavator]
Next, with reference to FIGS. 7 and 8, a specific example of a method for stabilizing the behavior during the discharge operation by the attachment of the excavator 100 will be described.

<First example of a method for stabilizing the behavior of a shovel>
FIG. 7 is a diagram showing a first example of a configuration for stabilizing the behavior of the excavator 100 during a discharge operation.

As shown in FIG. 7, the control valve 17D is a spool valve capable of moving toward both ends in the axial direction with respect to a predetermined neutral position by the pilot pressure of the hydraulic oil supplied through the pilot line 27. Is.

The control valve 17D includes pilot ports P1 and P2.

The control valve 17D is an elastic body (for example, a spring) from both ends in the axial direction so as to be balanced at a predetermined neutral position in the axial direction in a state where hydraulic oil (pilot pressure) is not supplied to any of the pilot ports P1 and P2. ). When the spool is in the neutral position, the control valve 17D communicates a center bypass oil passage for circulating hydraulic oil between the main pump 14 and the tank, and the oil passage and boom between the main pump 14 and the boom cylinder 7. The oil passage between the cylinder 7 and the tank is shut off.

The pilot port P1 is provided at one end (left end in the drawing) of the control valve 17D in the axial direction, and is connected to a pilot line 27 corresponding to an operation in the extension direction of the boom cylinder 7 (up direction of the boom 4). As a result, the control valve 17D moves the spool to the other end side with reference to the neutral position by the hydraulic oil supplied to the pilot port P1, and the boom cylinder 7 is adjusted to the operating state of the boom 4 (boom cylinder 7). The hydraulic oil in the bottom side oil chamber can be supplied and the hydraulic oil in the rod side oil chamber can be discharged to the tank.

The pilot port P2 is provided at the other end (right end in the drawing) of the control valve 17D in the axial direction, and is connected to a pilot line 27 corresponding to an operation in the contraction direction (lowering direction of the boom 4) of the boom cylinder 7. As a result, the hydraulic oil supplied to the pilot port P2 causes the control valve 17D to move the spool to one end side with reference to the neutral position, and to match the operating state of the boom 4 (boom cylinder 7) with the boom cylinder 7. The hydraulic oil can be supplied to the rod side oil chamber and the hydraulic oil can be discharged to the tank from the bottom side oil chamber.

Further, as shown in FIG. 7, in this example, the hydraulic control system of the excavator 100 includes a control valve 70.

The control valve 70 can supply the hydraulic oil discharged from the main pump 14 to the rod-side oil chamber of the boom cylinder 7, and can discharge the hydraulic oil in the rod-side oil chamber to the tank.

The control valve 70 includes two electromagnetic solenoids S1 and S2.

The control valve 70 is urged by an elastic body (for example, a spring) from both ends in the axial direction so as to be balanced at a predetermined neutral position in the axial direction in a state where no control current is applied to any of the electromagnetic solenoids S1 and S2. Has been done. When the spool is in the neutral position, the control valve 70 cuts off the hydraulic oil path between the main pump 14 and the boom cylinder 7, and the hydraulic oil between the rod side oil chamber of the boom cylinder 7 and the tank. Also blocks the route.

The electromagnetic solenoid S1 is provided at one end in the axial direction (left end in the figure), extends according to the control current applied from the controller 30, and has the spool axially from one end to the other end (in the figure) with reference to the neutral position. It is configured so that it can be moved toward (the right side of the inside).

The control valve 70 communicates the path between the main pump 14 and the boom cylinder 7 when the spool moves from one end to the other end with respect to the neutral position by the control current applied to the electromagnetic solenoid S1. Then, the control valve 70 supplies the hydraulic oil of the flow rate corresponding to the opening degree to the rod side oil chamber of the boom cylinder 7.

The electromagnetic solenoid S2 is provided at the other end in the axial direction, extends according to the control current applied from the controller 30, and can move the spool axially from the other end to one end with reference to the neutral position. Possible to be configured.

When the spool moves from the other end toward one end by the control current applied to the electromagnetic solenoid S2 with respect to the neutral position, the control valve 70 follows a path between the rod-side oil chamber of the boom cylinder 7 and the tank. Communicate. Then, the control valve 70 discharges the hydraulic oil having a flow rate corresponding to the opening degree from the rod-side oil chamber of the boom cylinder 7 to the tank.

As in the case of the control valve 17D, the control valve 70 may have a form in which the spool moves with the hydraulic oil supplied to the pilot ports at both ends in the axial direction. In this case, the two pilot ports of the control valve 70 each use the hydraulic oil supplied from the pilot pump 15 to output the hydraulic oil of the pilot pressure according to the control current from the controller 30. It may be connected to (eg, a proportional valve).

When the control execution condition is satisfied, the stabilization control unit 302 outputs a control command (control current) to the electromagnetic solenoid S1. As a result, the controller 30 can supply the hydraulic oil to the rod side oil chamber of the boom cylinder 7 while holding the hydraulic oil in the bottom side oil chamber of the boom cylinder 7 by using the control valve 70. Therefore, F1 in the extending direction acting on the rod and the force DG in the countering direction act on the boom cylinder 7 with the start of the discharge operation of the attachment, and the piston rod (boom 4) of the boom cylinder 7 moves. It can be suppressed. Therefore, the controller 30 can suppress the generation of the swinging back force F2 of the force F1 and suppress the decrease in the dynamic stability of the excavator 100, that is, the vibration of the excavator 100 and the tipping forward.

The flow rate of the hydraulic oil supplied from the control valve 70 to the rod side oil chamber of the boom cylinder 7 is, for example, the load state of the boom cylinder 7, that is, the weight of the contents contained in the bucket 6 at the start of the discharge operation. It may be controlled in consideration. This is because as the weight of the contents of the bucket 6 increases, the reaction force acting on the boom 4 due to the opening operation of the bucket 6 or the like at the start of the attachment discharging operation increases. That is, the stabilization control unit 302 may determine the control command value (control current value) in consideration of the weight of the contents accommodated in the bucket 6 at the start of the discharge operation. In this case, the stabilization control unit 302 measures (estimates) the weight of the contents contained in the bucket 6 based on the pressure of the oil chamber on the bottom side of the boom cylinder 7 immediately before the start of the discharge operation of the attachment, for example. It's okay. Further, the stabilization control unit 302 may recognize the contents of the bucket 6 and estimate the weight thereof based on the image captured by the image pickup device S6.

The flow rate of the hydraulic oil supplied from the control valve 70 to the rod-side oil chamber of the boom cylinder 7 may be controlled in consideration of, for example, the speed and acceleration of the opening operation of the bucket 6 and the arm 5. This is because as the speed and acceleration of the bucket 6 and the arm 5 increase, the reaction force acting on the boom 4 due to the opening operation of the bucket 6 and the like at the start of the attachment discharging operation increases. That is, the stabilization control unit 302 may determine the control command value (control current value) to be supplied to the electromagnetic solenoid S1 of the control valve 70 in consideration of the speed and acceleration of the opening operation of the bucket 6 and the arm 5. In this case, the stabilization control unit 302 may acquire the speed and acceleration of the arm 5 and the bucket 6 based on the outputs of the arm angle sensor S2 and the bucket angle sensor S3, for example. Further, the stabilization control unit 302 estimates the speed and acceleration of the arm 5 and the bucket 6 based on the output of the arm angle sensor S2 and the bucket angle sensor S3 based on the operation content (operation amount) of the arm 5 and the bucket 6. You may.

<Second example of the method of stabilizing the behavior of the excavator>
FIG. 8 is a diagram showing a second example of the configuration relating to the stabilization of the behavior of the excavator 100 during the discharging operation.

As shown in FIG. 8, in this example, when the control execution condition is satisfied, the stabilization control unit 302 outputs a control command (control current) to the hydraulic control valve 31 corresponding to the operation in the extension direction of the boom cylinder 7. , The hydraulic oil is supplied to the pilot port P1 of the control valve 17D. As a result, the controller 30 uses the control valve 17D to supply the hydraulic oil to the bottom side oil chamber of the boom cylinder 7 and discharge the hydraulic oil from the rod side oil chamber to the tank when the attachment is discharged. Can be done. Therefore, the controller 30 can positively move the boom cylinder 7 in the same direction as the extension direction F1 acting on the rod with the start of the attachment ejection operation, and suppress the generation of the swing-back force F2. .. Therefore, the controller 30 can suppress a decrease in the dynamic stability of the excavator 100, that is, vibration of the excavator 100, a fall forward, and the like.

The flow rate of the hydraulic oil supplied from the control valve 17D to the oil chamber on the bottom side of the boom cylinder 7 is, for example, the load state of the boom cylinder 7, that is, the bucket 6 at the start of the discharge operation, as in the case of the first example described above. It may be controlled in consideration of the weight of the contents contained in the cylinder. That is, the stabilization control unit 302 may determine the control command value (control current value) to the hydraulic control valve 31 in consideration of the weight of the content contained in the bucket 6 at the start of the discharge operation.

Further, the flow rate of the hydraulic oil supplied from the control valve 17D to the oil chamber on the bottom side of the boom cylinder 7 takes into consideration the speed and acceleration of the opening operation of the bucket 6 and the arm 5, as in the case of the first example described above. May be controlled. That is, the stabilization control unit 302 may determine the control command value (control current value) to be supplied to the hydraulic control valve 31 in consideration of the speed and acceleration of the opening operation of the bucket 6 and the arm 5.

[Control method for stabilizing the behavior of the shovel]
Next, with reference to FIGS. 9 to 11, a specific example of the control process relating to the stabilization of the behavior of the excavator 100 during the discharging operation will be described.

<First example of control method>
FIG. 9 is a flowchart schematically showing a first example of the control process relating to the stabilization of the behavior of the excavator 100 during the discharging operation. The process of this flowchart is repeatedly executed at predetermined control cycles during the operation of the excavator 100, that is, from the start (for example, key switch ON) to the stop (for example, the key switch OFF) of the excavator 100. Hereinafter, the same may apply to the processing of the flowcharts of FIGS. 10 and 11.

As shown in FIG. 9, in step S102, the determination unit 301 determines whether or not the attachment is performing the ejection operation. That is, the determination unit 301 determines the success or failure of the control execution essential condition. The determination unit 301 proceeds to step S104 when the attachment has started the ejection operation, and ends the current flowchart in other cases.

In step S104, the stabilization control unit 302 calculates a control command value for behavior stabilization. In the case of the above-mentioned FIG. 7 (first example), the stabilization control unit 302 calculates a control command value (control current value) to the control valve 70 (electromagnetic solenoid S1), and the above-mentioned FIG. 8 (second example). In the case of, the control command value (control current value) to the hydraulic control valve 31 corresponding to the pilot port P1 of the control valve 17D is calculated.

When the process of step S104 is completed, the controller 30 proceeds to step S106.

In step S106, the stabilization control unit 302 outputs a control command to the control valve 70 or the control valve 70 corresponding to the pilot port P1 of the control valve 17D based on the calculation result of step S104. As a result, the controller 30 can supply hydraulic oil to the boom cylinder 7 through the control valve 70 or the control valve 17D so as to suppress the swing-back force F2.

When the process of step S106 is completed, the controller 30 ends the process of the current flowchart.

As described above, in this example, the controller 30 supplies hydraulic oil to the boom cylinder 7 regardless of the operating state of the boom 4 when the attachment is discharged, and the dynamic stability of the excavator 100 is increased. It is possible to suppress a decrease (for example, vibration or a fall forward).

<Second example of control method>
FIG. 10 is a flowchart schematically showing a second example of the control process relating to the stabilization of the behavior of the excavator 100 during the discharging operation.

As shown in FIG. 10, step S202 is the same as the process of step S102 in FIG. 9, and therefore the description thereof will be omitted.

When the process of step S202 is completed, the controller 30 proceeds to step S204.

In step S204, the determination unit 301 determines whether or not the boom 4 is being operated. That is, the determination unit 301 determines whether or not "the operation of the boom 4 is not performed" as the control execution limiting condition is satisfied. If the boom 4 is not operated, the determination unit 301 proceeds to step S206, and if the boom 4 is operated, the determination unit 301 ends the processing of the current flowchart.

Since the processing of steps S206 and S208 is the same as that of steps S104 and S106 of FIG. 9, the description thereof will be omitted.

When the process of step S208 is completed, the controller 30 ends the process of the current flowchart.

As described above, in this example, the controller 30 applies hydraulic oil to the boom cylinder 7 only when the boom 4 (boom cylinder 7) is not operated when the attachment is discharged. Can be supplied. Thereby, for example, in a state where the operator is operating the boom 4, it is possible to suppress a situation in which the boom 4 performs an operation different from the operation and gives a sense of discomfort to the operator. Therefore, in this example, it is possible to suppress a decrease in the dynamic stability of the excavator 100 during the discharging operation while suppressing the operator's discomfort.

<Third example of control method>
FIG. 11 is a flowchart schematically showing a third example of the control process relating to the stabilization of the behavior of the excavator 100 during the discharging operation.

As shown in FIG. 11, since step S302 is the same as the process of step S102 in FIG. 9, the description thereof will be omitted.

When the process of step S302 is completed, the controller 30 proceeds to step S304.

In step S304, the determination unit 301 determines whether or not the excavator 100 (airframe) is likely to vibrate or tip over. That is, the determination unit 301 determines the success or failure of "the state in which the dynamic stability of the excavator 100 (airframe) is likely to decrease" as a control execution limiting condition.

In a state where the dynamic stability of the excavator 100 (airframe) is likely to decrease, for example, a state in which the bucket 6 contains an container exceeding a predetermined standard, in other words, a load on the attachment is a predetermined standard. The state exceeding is included. This is because the heavier the weight of the contained material such as earth and sand contained in the bucket 6, the greater the reaction force acting on the boom 4 due to the attachment discharging operation (opening operation of the bucket 6 or the like). The predetermined criterion may be, for example, greater than zero or zero. In the latter case, the determination unit 301 determines that the control execution limitation condition is satisfied if the bucket 6 contains even a small amount of the contained object.

Further, in a state where the dynamic stability of the excavator 100 (airframe) is likely to decrease, for example, the speed and acceleration of the bucket 6 and the arm 5 are relatively large (specifically, larger than a predetermined standard). ) The state is included. This is because, as described above, as the speed and acceleration of the opening operation of the bucket 6 and the arm 5 increase, the reaction force acting on the boom 4 due to the attachment discharging operation (opening operation of the bucket 6 and the like) increases.

The determination unit 301 proceeds to step S306 when the excavator 100 (airframe) is likely to vibrate or tip over, that is, when the dynamic stability is likely to be relatively reduced. Otherwise, the process proceeds to step S308.

Since steps S306 and S308 are the same as the processes of steps S104 and S106 of FIG. 9, the description thereof will be omitted.

When the process of step S308 is completed, the controller 30 ends the process of the current flowchart.

As described above, in this example, the controller 30 is limited to the case where the dynamic stability of the excavator 100 (airframe) is likely to be relatively lowered when the attachment is ejected. Hydraulic oil can be supplied to the boom cylinder 7. As a result, for example, in a situation where the bucket 6 has no contents and the excavator 100 (airframe) is unlikely to vibrate or tip over, the boom 4 operates regardless of the operation, giving the operator a sense of discomfort. It is possible to suppress such a situation. Therefore, in this example, it is possible to suppress a decrease in the dynamic stability of the excavator 100 during the discharging operation while suppressing the operator's discomfort.

<Other examples of control methods>
The above-mentioned second example and the third example may be combined.

Specifically, the stabilization control unit 302 corresponds to steps S206 and S208 (steps S306 and S308) when both the control execution limiting conditions corresponding to step S204 in FIG. 10 and step S304 in FIG. 11 are satisfied. It may be in the form of performing the processing. In this case, the same determination process as in step S304 may be inserted between step S202 and step S204, or between step S204 and step S206.

As a result, in this example, the excavator 100 exhibits the actions and effects of both the second and third examples described above.

[Action]
Next, the operation of the excavator 100 according to the present embodiment will be described.

In the present embodiment, the excavator 100 includes a lower traveling body 1, an upper swivel body 3 rotatably mounted on the lower traveling body, a boom 4 attached to the upper swivel body 3, and an arm 5 attached to the tip of the boom 4. And an attachment including a bucket attached to the tip of the arm 5, and a boom cylinder 7 for driving the boom 4. Then, the excavator 100 supplies hydraulic oil to the boom cylinder 7 regardless of the operating state of the boom 4 when the attachment performs a discharge operation for discharging the contents of the bucket 6 to the outside.

For example, when the attachment discharges, the reaction force of the opening operation of the arm 5 and the bucket 6 exerts a force in the extension direction on the boom cylinder 7 to reduce the load, and then the boom cylinder 7 swings back. A force in the contraction direction acts on the cylinder, increasing its load. As a result, when the load (pressure) of the boom cylinder increases or decreases, the hydraulic oil inside the boom cylinder 7 acts as a spring element, and the entire attachment vibrates, which may cause the airframe to vibrate or the airframe to tip over. be.

On the other hand, in the present embodiment, the excavator 100 can supply hydraulic oil to the boom cylinder 7 regardless of the operating state of the boom 4 when the attachment performs the discharging operation. Therefore, the excavator 100 can suppress an increase / decrease in the load (pressure) of the boom cylinder 7 by the hydraulic oil supplied to the boom cylinder 7, and can suppress vibration and overturning of the excavator 100. Therefore, the dynamic stability of the excavator 100 can be improved.

Further, in the present embodiment, the excavator 100 supplies hydraulic oil to the boom cylinder 7 in order to improve the dynamic stability. Therefore, the excavator 100 suppresses the movement of the boom 4 in the lowering direction by its own weight, as in the method of discharging the hydraulic oil of the boom cylinder 7 to the outside and suppressing the function of the hydraulic oil as a spring element. be able to. Therefore, the static stability of the excavator 100 and the safety of the excavator 100 can be further improved.

Further, in the present embodiment, when the attachment discharges, the excavator 100 suppresses the swing-back operation of the boom cylinder 7 in the contraction direction due to the force in the extension direction acting on the boom cylinder 7 due to the discharge operation of the attachment. As such, hydraulic oil may be supplied to the boom cylinder 7.

As a result, the excavator 100 suppresses the swing-back operation of the boom cylinder 7 in the contraction direction, which causes a decrease in the dynamic stability of the excavator 100 (for example, vibration or overturning). It is possible to suppress the increase / decrease of the load of.

Further, in the present embodiment, when the attachment performs the discharge operation, the excavator 100 supplies the hydraulic oil to the bottom side oil chamber of the boom cylinder 7 and discharges the hydraulic oil from the rod side oil chamber of the boom cylinder 7. The boom 4 may be moved in the upward direction.

As a result, the excavator 100 supplies and discharges the hydraulic oil of the boom cylinder 7 so as to be synchronized with the force in the extension direction acting on the boom cylinder 7 as a reaction force of the operation of the arm 5 and the bucket 6 during the discharge operation, and the boom. 4 can be moved in the upward direction. Therefore, the excavator 100 suppresses the swinging back operation of the boom cylinder 7 in the contraction direction, and suppresses the fluctuation of the load (pressure) of the boom cylinder 7 which causes a decrease in the dynamic stability of the excavator 100. Can be done.

Further, in the present embodiment, when the attachment discharges, the excavator 100 supplies the hydraulic oil to the rod side oil chamber while holding the hydraulic oil in the bottom side oil chamber of the boom cylinder 7, and is in the extension direction. The movement of the boom 4 in the raising direction due to the force may be suppressed.

As a result, the excavator 100 supplies hydraulic oil only to the rod-side oil chamber of the boom cylinder 7, and opposes the force in the extension direction acting on the boom cylinder 7 as a reaction force of the operation of the arm 5 and the bucket 6 during the discharge operation. The drag force can be applied to the boom cylinder 7. Therefore, the excavator 100 can suppress the movement of the boom cylinder 7 at the start of the discharge operation of the attachment, and as a result, can suppress the operation of swinging back the boom cylinder 7 in the contraction direction. Therefore, the excavator 100 can suppress fluctuations in the load (pressure) of the boom cylinder 7, which causes a decrease in the dynamic stability of the own machine (excavator 100).

Further, in the present embodiment, the excavator 100 may supply hydraulic oil to the boom cylinder 7 when the attachment is discharging while the boom 4 is not operated.

As a result, the excavator 100 can supply the hydraulic oil to the boom cylinder 7 in accordance with the discharge operation of the attachment only in the state where the boom 4 is not operated. Therefore, the excavator 100 gives priority to the operation of the boom 4 when the boom 4 is operated while suppressing the decrease in the dynamic stability of the excavator 100, and operates the boom 4 according to the operation. Can be realized.

Further, in the present embodiment, the excavator 100 is attached to the boom cylinder 7 when the attachment is ejecting in a state where the dynamic stability of the own machine (excavator 100) is relatively likely to decrease. Hydraulic oil may be supplied.

As a result, the excavator 100 can supply the hydraulic oil to the boom cylinder 7 accompanying the discharge operation of the attachment only in a state where there is a high possibility that the excavator 100 actually vibrates or falls. Therefore, the excavator 100 suppresses a decrease in the dynamic stability of the own machine (excavator 100) due to the discharge operation of the attachment, and at the same time, the operator feels uncomfortable due to the hydraulic oil being supplied to the boom cylinder 7 regardless of the operation. Can be suppressed.

Further, in the present embodiment, the state in which the dynamic stability of the excavator 100 is relatively likely to decrease may include a state in which the bucket 6 contains an container exceeding a predetermined standard.

As a result, the excavator 100 is booming in a situation where a large amount of earth and sand or other contained matter is accommodated in the bucket 6 and the reaction force of the operation of the arm 5 and the bucket 6 due to the discharge operation of the attachment tends to be relatively large. Hydraulic oil can be supplied to the cylinder 7. Therefore, the excavator 100 can suppress a dynamic decrease in stability (for example, vibration of the machine body, overturning, etc.) according to a specific situation.

Further, in the present embodiment, the state in which the dynamic stability of the excavator 100 is relatively likely to decrease includes a state in which the velocity or acceleration of at least one of the arm 5 and the bucket 6 is relatively large. It's okay.

As a result, in the excavator 100, the speed and acceleration of the arm 5 and the bucket 6 at the time of discharging the attachment tend to be relatively high, and the reaction force of the operation of the arm 5 and the bucket 6 tends to be relatively large. Hydraulic oil can be supplied to the boom cylinder 7. Therefore, the excavator 100 can suppress a dynamic decrease in stability according to a specific situation.

Further, in the present embodiment, when the attachment performs the discharging operation, the excavator 100 uses the boom cylinder with a flow rate of hydraulic oil according to the acceleration of the boom 4, the acceleration of the arm 5, and the load state of the attachment by the contents of the bucket 6. 7 may be supplied.

As a result, the excavator 100 suppresses fluctuations in the load (pressure) of the boom cylinder 7 according to the acceleration of the arm 5 and the bucket 6 during the discharge operation of the attachment and the load state of the attachment due to the contents of the bucket 6. It is possible to supply hydraulic oil with an appropriate flow rate.

[Transform / Change]
Although the embodiments have been described in detail above, the present disclosure is not limited to such a specific embodiment, and various modifications and changes can be made within the scope of the gist described in the claims.

For example, in the above-described embodiment, the excavator 100 is configured to hydraulically drive all the driven elements such as the lower traveling body 1, the upper swivel body 3, the boom 4, the arm 5, and the bucket 6. Alternatively, the entire structure may be electrically driven by an electric actuator. That is, the configuration and the like disclosed in the above-described embodiment may be applied to a hybrid excavator, an electric excavator, or the like.

1 Lower traveling body 1ML, 1MR Traveling hydraulic motor 2A Swing hydraulic motor 3 Upper swivel body 4 Boom 5 Arm 6 Bucket 7 Boom cylinder 8 Arm cylinder 9 Bucket cylinder 10 Cabin 11 Engine 13 Regulator 14 Main pump 15 Pilot pump 17 Control valve 17A ~ 17F Control valve 25, 25A, 25B, 27, 27A, 27B Pilot line 25V Gate lock valve 30 Controller 31 Hydraulic control valve 33 Hydraulic control valve 50 Output device 52 Input device 60 Communication device 70 Control valve 100 Excavator 200 Management device 301 Judgment unit 302 Stabilization control unit S1 Boom angle sensor S2 Arm angle sensor S3 Bucket angle sensor S4 Machine tilt sensor S5 Swing state sensor S6 Imaging device S7 Boom cylinder pressure sensor S8 Arm cylinder pressure sensor S9 Bucket cylinder pressure sensor

Claims (9)

With the lower running body,
The upper swivel body that is freely mounted on the lower traveling body and the upper swivel body
An attachment including a boom attached to the upper swing body, an arm attached to the tip of the boom, and a bucket attached to the tip of the arm.
With a boom cylinder for driving the boom,
When the attachment performs a discharge operation for discharging the contents of the bucket to the outside, hydraulic oil is supplied to the boom cylinder regardless of the operating state of the boom.
Excavator. When the attachment performs the discharging operation, the boom cylinder is prevented from swinging back in the contraction direction of the boom cylinder due to an extension force acting on the boom cylinder due to the discharging operation of the attachment. Supply hydraulic oil to
The excavator according to claim 1. When the attachment performs the discharge operation, the hydraulic oil is supplied to the oil chamber on the bottom side of the boom cylinder, the hydraulic oil is discharged from the oil chamber on the rod side of the boom cylinder, and the boom is moved in the upward direction.
The excavator according to claim 2. When the attachment performs the discharge operation, the hydraulic oil is supplied to the rod side oil chamber while holding the hydraulic oil in the bottom side oil chamber of the boom cylinder, and the boom is raised in the direction of the extension force. Suppress the movement to,
The excavator according to claim 2. When the attachment is performing the discharging operation when the boom is not operated, hydraulic oil is supplied to the boom cylinder.
The excavator according to any one of claims 1 to 4. When the attachment is performing the discharging operation in a state where the dynamic stability of the excavator is relatively likely to decrease, hydraulic oil is supplied to the boom cylinder.
The excavator according to any one of claims 1 to 5. A condition in which the excavator's dynamic stability is relatively likely to be reduced includes a condition in which the bucket contains more than a predetermined standard.
The excavator according to claim 6. Conditions in which the dynamic stability of the excavator is relatively likely to decrease include conditions in which the velocity or acceleration of at least one of the arm and the bucket is relatively high.
The excavator according to claim 6 or 7. When the attachment performs the discharging operation, the boom cylinder is supplied with a flow rate of hydraulic oil according to the acceleration of the boom, the acceleration of the attachment, and the load state of the attachment by the contents of the bucket.
The excavator according to any one of claims 1 to 8.

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