Shovel and end attachment changing method

Abstract

The present disclosure provides a shovel in which an end attachment can be easily replaced.SOLUTION: The shovel 100 includes a lower traveling body 1, an upper turning body 3, an attachment AT, and a controller. The attachment AT includes a bucket 6 rotatably provided via a first pin P1, and a link mechanism L attached to the bucket 6 via a second pin P2 to rotate the bucket 6. The controller has an end attachment replacement mode for acquiring a first posture of the attachment AT in which a load acting on the first pin P1 or the second pin P2 due to the own weight of the bucket 6 is equal to or less than a predetermined value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an excavator and a method for replacing an end attachment. [Background technology]

[0002] Dummy pins used in replacing end attachments attached to excavators have been known for some time (see Patent Document 1 below). The dummy pin described in Patent Document 1 has an outer diameter smaller than the inner diameter of a pin hole provided in an arm for inserting an attachment pin, and is made of a round steel bar with chamfered ends on both longitudinal ends.

[0003] The replacement of an end attachment using a dummy pin in Patent Document 1 is carried out as follows: The dummy pin is inserted into the pin hole in which the mounting pin of the end attachment is inserted, and the mounting pin is pushed out of the pin hole. Then, if necessary, the end attachment is removed with the dummy pin left in the pin hole, and a different end attachment is attached. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-183387 Summary of the Invention [Problem to be solved by the invention]

[0005] When replacing an end attachment that uses a dummy pin as described in Patent Document 1, the load caused by the end attachment's own weight and the reaction force that the end attachment receives from the ground surface tends to act on the attachment pin and dummy pin, which can make it difficult to remove the attachment pin and dummy pin, making it difficult to replace the end attachment.

[0006] The present disclosure provides a shovel that allows for easy replacement of an end attachment, and a method for replacing an end attachment. [Means for solving the problem]

[0007] One aspect of the present disclosure provides a shovel comprising a lower running body, an upper rotating body rotatably mounted on the lower running body, an attachment mounted on the upper rotating body, and a controller that acquires the attitude of the attachment, wherein the attachment has an end attachment rotatably mounted via a first pin and a link mechanism attached to the end attachment via a second pin and rotates the end attachment, and the controller has an end attachment exchange mode that acquires a first attitude of the attachment in which the load acting on the first pin or the second pin due to the weight of the end attachment is below a threshold.

[0008] Another aspect of the present disclosure provides a method for replacing an end attachment of a shovel, wherein the shovel comprises a lower running body, an upper rotating body rotatably mounted on the lower running body, and an attachment mounted on the upper rotating body, the attachment having the end attachment rotatably mounted via a first pin and a link mechanism attached to the end attachment via a second pin and rotating the end attachment, the method including a step of causing the attachment to assume a first posture in which the load acting on the first pin or the second pin due to the weight of the end attachment is equal to or less than a threshold value. [Effects of the Invention]

[0009] According to the above aspects of the present disclosure, it is possible to provide a shovel that allows for easy replacement of an end attachment, and a method for replacing an end attachment. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. [Figure 2] FIG. 2 is a block diagram showing the configuration of a shovel. [Figure 3] FIG. 2 is a functional block diagram of a controller of the excavator. [Figure 4] FIG. 10 is a flow chart illustrating an example of a method for replacing an end attachment. [Figure 5] FIG. 10 is a process diagram illustrating an example of a method for replacing an end attachment. [Figure 6] FIG. 10 is an image diagram showing an example of a guidance image displayed on a display device of the shovel. [Figure 7] 10A to 10C are process diagrams illustrating another example of a method for replacing an end attachment. [Figure 8] FIG. 10 is a flow chart illustrating another example of a method for replacing an end attachment. [Figure 9] 9 is a process diagram illustrating a method for replacing the end attachment shown in FIG. 8. [Figure 10] FIG. 1 is a block diagram showing a configuration of an excavator operation support system. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the shovel and end attachment exchange direction according to the present disclosure will be described with reference to the drawings. The embodiments described below are examples and do not limit the invention. Not all features and combinations thereof in the embodiments of the present disclosure are necessarily essential to the invention. Note that the same or corresponding components in each drawing will be designated by the same or corresponding reference numerals, and redundant description may be omitted.

[0012] [Embodiment 1] Fig. 1 is a side view showing a first embodiment of a shovel according to the present disclosure. Fig. 2 is a block diagram showing an example of the configuration of the shovel 100 shown in Fig. 1. In Fig. 2, paths through which mechanical power is transmitted are indicated by double lines, paths through which high-pressure hydraulic oil that drives the hydraulic actuator HA flows are indicated by solid lines, paths through which pilot pressure is transmitted are indicated by dashed lines, and paths through which electrical signals are transmitted are indicated by dotted lines.

[0013] Hereinafter, the direction in which the attachment AT of the shovel 100 extends (leftward in FIG. 1) will be defined as "front," and directions at the shovel 100 or as seen from the shovel 100 may be described.

[0014] As shown in Fig. 1, the excavator 100 includes a lower traveling body 1, an upper rotating body 3, and an attachment AT. The attachment AT includes, for example, a boom 4, an arm 5, a bucket 6, and a link mechanism L. The boom 4, the arm 5, and the bucket 6 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, respectively.

[0015] The lower traveling body 1 uses crawlers 1C to travel the excavator 100. Specifically, the lower traveling body 1 has a left crawler 1C and a right crawler 1C. The left crawler 1C is hydraulically driven by a traveling hydraulic motor 1ML. Similarly, the right crawler 1C is hydraulically driven by a traveling hydraulic motor 1MR. This allows the lower traveling body 1 to travel on its own.

[0016] The upper rotating body 3 is rotatably mounted on the lower traveling body 1. The upper rotating body 3 rotates relative to the lower traveling body 1, for example, when the rotating mechanism 2 is hydraulically driven by a swing hydraulic motor 2M. In addition, a cabin 10 in which the operator of the excavator 100 boards is provided on the front left side of the upper rotating body 3.

[0017] The boom 4 is rotatably attached to the center of the front of the upper rotating body 3. Specifically, the boom 4 is rotatable around a boom foot pin 4f attached to the upper rotating body 3 along the left-right direction.

[0018] The arm 5 is rotatably attached to the tip of the boom 4. Specifically, the arm 5 is provided rotatably around a boom top pin 4t attached to the tip of the boom 4 along the left-right direction.

[0019] The bucket 6 is rotatably attached to the tip of the arm 5. Specifically, the bucket 6 is provided so as to be rotatable about a first pin P1 attached to the tip of the arm 5 along the left-right direction. The first pin P1 is also referred to as a bucket pin 6p or an arm top pin, for example. The bucket 6 is an example of an end attachment of the excavator 100, and is used, for example, for excavation work, slope work, and ground leveling work.

[0020] The bucket 6 is attached to the tip of the arm 5 in a manner that allows it to be appropriately replaced depending on the type of work being performed by the excavator 100. In other words, instead of the bucket 6, a bucket of a different type from the bucket 6, such as a relatively large bucket, a slope bucket, or a dredging bucket, may be attached to the tip of the arm 5. Also, a type of end attachment other than a bucket, such as an agitator, breaker, crusher, demolition fork, magnet, or grapple, may be attached to the tip of the arm 5. Also, a spare attachment such as a quick coupling or tiltrotator may be provided between the arm 5 and the end attachment.

[0021] The link mechanism L is attached to the end attachment including the bucket 6 via a second pin P2 to rotate the end attachment including the bucket 6. The second pin P2 is also referred to as a link pin Lp, for example. Specifically, the link mechanism L has, for example, a first link L1 and a second link L2.

[0022] For example, one end of the first link L1 is rotatably attached to the tip of the arm 5, and the other end is rotatably attached to the tip of the piston rod of the bucket cylinder 9. For example, one end of the second link L2 is rotatably attached to the tip of the piston rod of the bucket cylinder 9, and the other end is rotatably attached to the end attachment including the bucket 6 via a second pin P2.

[0023] With this configuration, when the piston rod of the bucket cylinder 9 extends, the link mechanism L rotates the end attachment including the bucket 6 about the first pin P1 so as to close it relative to the arm 5. On the other hand, when the piston rod of the bucket cylinder 9 contracts, the link mechanism L rotates the end attachment including the bucket 6 about the first pin P1 so as to open it relative to the arm 5. In other words, the link mechanism L converts the linear motion of the bucket cylinder 9 into rotational motion about the first pin P1.

[0024] The excavator 100 operates driven elements such as the lower running body 1 (i.e., a pair of left and right crawlers 1C, 1C), upper rotating body 3, boom 4, arm 5, and bucket 6, for example, in response to operations by an operator seated in the cabin 10.

[0025] The excavator 100 may also automatically operate the actuators regardless of the operation by the operator. This allows the excavator 100 to realize a function of automatically operating at least some of the driven elements such as the lower traveling body 1, the upper rotating body 3, and the attachment AT, i.e., a so-called "automatic driving function" or "machine control (MC) function."

[0026] The automatic driving function includes, for example, a semi-automatic driving function (an operation-assisted MC function). The semi-automatic driving function is a function that automatically operates driven elements (actuators) other than the driven element (actuator) to be operated in response to an operator's operation. The automatic driving function may also include a fully automatic driving function (a fully automatic MC function). The fully automatic driving function is a function that automatically operates at least some of the multiple driven elements (actuators) without any operator operation. In the excavator 100, when the fully automatic driving function is enabled, the inside of the cabin 10 may be unmanned. The semi-automatic driving function, the fully automatic driving function, etc. include, for example, a rule-based automatic driving function. The rule-based automatic driving function is an automatic driving function in which the operation content of the driven element (actuator) that is the target of automatic driving is automatically determined in accordance with predefined rules. The semi-automatic driving function, the fully automatic driving function, etc. may also include an autonomous driving function. The autonomous driving function is an automatic driving function in which the excavator 100 autonomously makes various decisions, and the operation details of the driven elements (actuators) that are the targets of the automatic driving are determined based on the results of those decisions.

[0027] The shovel 100 includes various components, such as a hydraulic drive system for hydraulically driving the driven elements, an operation system for operating the driven elements, a user interface system for exchanging information with the user, a communication system for communicating with the outside world, and a control system for various controls.

[0028] 2, the hydraulic drive system of the excavator 100 includes a hydraulic actuator HA that hydraulically drives each of the driven elements, such as the lower traveling structure 1 (left and right crawlers 1C, 1C), the upper rotating structure 3, the boom 4, the arm 5, and the bucket 6. The hydraulic drive system of the excavator 100 according to this embodiment also includes an engine 11, a regulator 13, a main pump 14, and a control valve 17.

[0029] The hydraulic actuators HA include traveling hydraulic motors 1ML, 1MR, a swing hydraulic motor 2M, a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9. Note that in the excavator 100, some or all of the hydraulic actuators HA may be replaced with electric actuators. In other words, the excavator 100 may be a hybrid excavator or an electric excavator.

[0030] The engine 11 is a prime mover of the excavator 100 and the main power source in the hydraulic drive system. The engine 11 is, for example, a diesel engine that uses diesel as fuel. The engine 11 is mounted, for example, on the rear of the upper rotating body 3. The engine 11 rotates at a constant speed at a preset target rotation speed under direct or indirect control by a controller 30 (described later), for example, and drives the main pump 14 and the pilot pump 15. Note that instead of or in addition to the engine 11, another prime mover (for example, an electric motor) or the like may be mounted on the excavator 100.

[0031] 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 referred to as the "tilting angle") in response to a control command from the controller 30.

[0032] The main pump 14 supplies hydraulic oil to the control valve 17 through a high-pressure hydraulic line. The main pump 14 is mounted, for example, on the rear of the upper rotating body 3, similar to the engine 11. As described above, the main pump 14 is driven by the engine 11. The main pump 14 is, for example, a variable displacement hydraulic pump. As described above, under the control of the controller 30, the regulator 13 adjusts the tilt angle of the swash plate to adjust the stroke length of the piston, thereby controlling the discharge flow rate and discharge pressure of the main pump 14.

[0033] The control valve 17 drives the hydraulic actuators HA in response to an operator's operation of the operating device 26, the details of remote operation, or an operation command corresponding to the automatic operation function. The control valve 17 is mounted, for example, in the center of the upper rotating body 3. As described above, the control valve 17 is connected to the main pump 14 via a high-pressure hydraulic line, and selectively supplies hydraulic oil supplied from the main pump 14 to each hydraulic actuator in response to an operator's operation or an operation command corresponding to the automatic operation function. Specifically, the control valve 17 includes a plurality of control valves (directional control valves) that control the flow rate and flow direction of hydraulic oil supplied from the main pump 14 to each hydraulic actuator HA.

[0034] As shown in FIG. 2, the operating system of the excavator 100 includes a pilot pump 15, an operating device 26, a hydraulic control valve 31, a shuttle valve 32, and a hydraulic control valve 33.

[0035] The pilot pump 15 supplies pilot pressure to various hydraulic devices via a pilot line 25. The pilot pump 15 is mounted, for example, on the rear of the upper rotating body 3, similar to the engine 11. The pilot pump 15 is, for example, a fixed displacement hydraulic pump, and is driven by the engine 11 as described above. The pilot pump 15 may be omitted. In this case, the relatively high-pressure hydraulic oil discharged from the main pump 14 is reduced in pressure by a predetermined pressure reducing valve, and the resulting relatively low-pressure hydraulic oil may be supplied to various hydraulic devices as pilot pressure.

[0036] The operating device 26 is provided near the cockpit of the cabin 10 and is used by the operator to operate the various driven elements. Specifically, the operating device 26 is used by the operator to operate the hydraulic actuators HA that drive the respective driven elements, thereby enabling the operator to operate the driven elements that are the targets of the hydraulic actuators HA. The operating device 26 includes pedal devices and lever devices for operating the respective driven elements (hydraulic actuators HA).

[0037] For example, as shown in Fig. 2, the operating device 26 is of a hydraulic pilot type. Specifically, the operating device 26 uses hydraulic oil supplied from the pilot pump 15 through a pilot line 25 and a pilot line 25A branching from the pilot line 25, and outputs a pilot pressure corresponding to the operation to a secondary pilot line 27A. The pilot line 27A is connected to one inlet port of a shuttle valve 32, and is connected to the control valve 17 via a pilot line 27 connected to an outlet port of the shuttle valve 32. This allows pilot pressure corresponding to the operation of various driven elements (hydraulic actuators HA) in the operating device 26 to be input to the control valve 17 via the shuttle valve 32. Therefore, the control valve 17 can drive each hydraulic actuator HA according to the operation of the operating device 26 by an operator or the like.

[0038] Furthermore, the operating device 26 may be electric. In this case, the pilot line 27A, the shuttle valve 32, and the hydraulic control valve 33 are omitted. Specifically, the operating device 26 outputs an electric signal (hereinafter referred to as an "operation signal") corresponding to the operation content, and the operation signal is input to the controller 30. The controller 30 then outputs a control command corresponding to the operation signal, that is, a control signal corresponding to the operation content of the operating device 26, to the hydraulic control valve 31. As a result, a pilot pressure corresponding to the operation content of the operating device 26 is input from the hydraulic control valve 31 to the control valve 17, and the control valve 17 can drive each hydraulic actuator HA according to the operation content of the operating device 26.

[0039] Furthermore, the control valves (directional control valves) that are built into the control valve 17 and drive the hydraulic actuators HA may be of an electromagnetic solenoid type. In this case, an operation signal output from the operating device 26 may be directly input to the control valve 17 (i.e., to the electromagnetic solenoid type control valve).

[0040] Furthermore, as described above, some or all of the hydraulic actuators HA may be replaced with electric actuators. In this case, the controller 30 may output a control command to the electric actuator or a driver that drives the electric actuator, etc., according to the operation content of the operation device 26 and the content of the remote operation specified by the remote operation signal. Furthermore, when the shovel 100 is remotely operated, the operation device 26 may be omitted. The shovel 100 can also be remotely operated using, for example, a mobile information terminal.

[0041] A hydraulic control valve 31 is provided for each driven element (hydraulic actuator HA) operated by the operating device 26 and for each drive direction of the driven element (hydraulic actuator HA) (e.g., the raising and lowering directions of the boom 4). For example, two hydraulic control valves 31 are provided for each double-acting hydraulic actuator HA for driving the undercarriage 1, the upper rotating body 3, the boom 4, the arm 5, the bucket 6, etc. The hydraulic control valve 31 may be provided, for example, in the pilot line 25B between the pilot pump 15 and the control valve 17 and configured to change its flow area (i.e., the cross-sectional area through which hydraulic oil can flow). This allows the hydraulic control valve 31 to output a predetermined pilot pressure to the secondary pilot line 27B using the hydraulic oil from the pilot pump 15 supplied through the pilot line 25B. Therefore, the hydraulic control valve 31 can indirectly apply a predetermined pilot pressure to the control valve 17 in response to a control signal from the controller 30 via a shuttle valve 32 between the pilot line 27B and the pilot line 27B. Therefore, for example, the controller 30 can cause the hydraulic control valve 31 to supply pilot pressure according to an operation command corresponding to the automatic operation function to the control valve 17, thereby realizing operation of the excavator 100 using the automatic operation function.

[0042] In addition, if the operating device 26 is electric, the controller 30 can supply pilot pressure corresponding to the operation content (operation signal) of the operating device 26 directly to the control valve 17 from the hydraulic control valve 31, thereby realizing operation of the shovel 100 based on the operation of the operator.

[0043] The shuttle valve 32 has two inlet ports and one outlet port, and outputs hydraulic oil having the higher pilot pressure of the two pilot pressures input to the two inlet ports to the outlet port. Similar to the hydraulic control valve 31, a shuttle valve 32 is provided for each driven element (hydraulic actuator HA) to be operated by the operating device 26 and for each drive direction of the driven element (hydraulic actuator HA). For example, two shuttle valves 32 are provided for each double-acting hydraulic actuator HA for driving the undercarriage 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc.

[0044] One of the two inlet ports of the shuttle valve 32 is connected to a pilot line 27A on the secondary side of the operating device 26 (specifically, the above-mentioned lever device or pedal device included in the operating device 26), and the other is connected to a 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 the hydraulic actuator HA, which is the object of operation of the above-mentioned lever device or pedal device connected to one inlet port of the shuttle valve 32.

[0045] Therefore, each of these shuttle valves 32 can apply the higher of the pilot pressure in pilot line 27A on the secondary side of the operating device 26 and the pilot pressure in pilot line 27B on the secondary side of the hydraulic control valve 31 to the pilot port of the corresponding control valve. In other words, by outputting a pilot pressure higher than the pilot pressure on the secondary side of the operating device 26 from the hydraulic control valve 31, the controller 30 can control the corresponding control valve regardless of the operation of the operating device 26 by the operator. Therefore, the controller 30 can control the operation of the driven elements (undercarriage 1, upper revolving body 3, boom 4, arm 5, bucket 6) regardless of the operating state of the operating device 26 by the operator, thereby realizing an automatic operation function and a remote operation function.

[0046] The hydraulic control valve 33 is provided in a pilot line 27A that connects the operating device 26 and the shuttle valve 32. The hydraulic control valve 33 is configured, for example, to be able to change the flow path area. The hydraulic control valve 33 operates in response to a control signal input from the controller 30.

[0047] As a result, for example, when the operating device 26 is being operated by an operator, the controller 30 can forcibly reduce the pilot pressure output from the operating device 26. Therefore, even when the operating device 26 is being operated, the controller 30 can forcibly suppress or stop the operation of the hydraulic actuator HA corresponding to the operation of the operating device 26.

[0048] Furthermore, for example, even when the operating device 26 is being operated by an operator, the controller 30 can reduce the pilot pressure output from the operating device 26 to be lower than the pilot pressure output from the hydraulic control valve 31. Therefore, by controlling the hydraulic control valves 31 and 33, the controller 30 can reliably apply a desired pilot pressure to the pilot port of the control valve in the control valve 17, regardless of the operation of the operating device 26, for example.

[0049] Therefore, the controller 30 can more appropriately realize the automatic operation function and remote control function of the excavator 100 by controlling the hydraulic control valve 33 in addition to the hydraulic control valve 31, for example.

[0050] As shown in FIG. 2, the user interface system of the shovel 100 includes an operation device 26, an output device 50, and an input device 52.

[0051] The output device 50 outputs various information to a user of the shovel 100 (for example, an operator of the cabin 10 or an external remote control operator) or to people in the vicinity of the shovel 100 (for example, a worker or a driver of a work vehicle).

[0052] The output device 50 includes, for example, lighting equipment, display devices, etc. that output various types of information visually. The lighting equipment is, for example, a warning light (indicator lamp), etc. The display device is, for example, a liquid crystal display, an organic EL (Electroluminescence) display, etc. The lighting equipment and display devices may be provided, for example, inside the cabin 10, and output various types of information visually to an operator, etc. inside the cabin 10. The lighting equipment and display devices may also be provided, for example, on the side of the upper rotating body 3, and output various types of information visually to workers, etc. around the excavator 100.

[0053] The output device 50 may also include a sound output device that outputs various types of information auditorily. Examples of sound output devices include a buzzer and a speaker. The sound output device may be provided, for example, inside or outside the cabin 10, and may output various types of information auditorily to an operator inside the cabin 10 or to people (workers, etc.) around the excavator 100. The output device 50 may also include a device that outputs various types of information tactilely, such as by vibrating the operator's seat.

[0054] The input device 52 accepts various inputs from a user of the excavator 100. A signal corresponding to the input accepted by the input device 52 is taken into the controller 30. For example, as shown in FIG. 2 , the input device 52 is provided inside the cabin 10 and accepts inputs from an operator or the like inside the cabin 10. The input device 52 may also be provided, for example, on the side of the upper rotating body 3 and accept inputs from a worker or the like around the excavator 100.

[0055] For example, the input device 52 includes a mechanical input device that accepts input from a user through mechanical operation. The mechanical input device may include 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.

[0056] The input device 52 may also include a voice input device that accepts voice input from the user. The voice input device may include, for example, a microphone. The input device 52 may also include a gesture input device that accepts gesture input from the user. The gesture input device may include, for example, an imaging device that captures images of gestures made by the user. The input device 52 may also include a biometric input device that accepts biometric input from the user. The biometric input may include, for example, input of biometric information such as the user's fingerprint or iris.

[0057] As shown in FIG. 2, the communication system of the shovel 100 according to this embodiment includes a communication device 60.

[0058] The communication device 60 is connected to an external communication line NW and communicates with devices provided separately from the shovel 100. The devices provided separately from the shovel 100 may include devices external to the shovel 100, as well as a portable terminal device (mobile terminal) brought into the cabin 10 by the user of the shovel 100. The communication device 60 may include, for example, a mobile communication module conforming to standards such as 4G (4th Generation) and 5G (5th Generation). The communication device 60 may also include, for example, a satellite communication module. The communication device 60 may also include, for example, a WiFi communication module or a Bluetooth (registered trademark) communication module. When there are multiple connectable communication line NWs, the communication device 60 may include multiple communication devices according to the types of the communication line NWs.

[0059] The communication device 60 communicates with the remote operation support device 200 within the work site and external devices such as the remote operation support device 200, for example, through a local communication line established at the work site. The local communication line is, for example, a local 5G (so-called local 5G) mobile communication line established at the work site or a local network using WiFi 6. The communication device 60 may also communicate with a remote operation support device or the like outside the work site through a wide-area communication line that includes the work site, i.e., a wide-area network.

[0060] 2, the control system of the shovel 100 includes a controller 30. The control system of the shovel 100 according to this embodiment also includes an operating pressure sensor 29, an imaging device 40, and sensors S1 to S9.

[0061] The controller 30 performs various controls related to the shovel 100. The functions of the controller 30 may be realized by any hardware or any combination of hardware and software. For example, as shown in FIG. 2, the controller 30 includes an auxiliary storage device 30A, a memory device 30B, a CPU (Central Processing Unit) 30C, and an interface device 30D, which are connected by a bus BS1.

[0062] The auxiliary storage device 30A is a nonvolatile storage means that stores the program to be installed as well as necessary files, data, etc. The auxiliary storage device 30A is, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a flash memory. For example, when a program startup instruction is received, the memory device 30B loads the program from the auxiliary storage device 30A so that it can be read by the CPU 30C. The memory device 30B is, for example, an SRAM (Static Random Access Memory).

[0063] The CPU 30C, for example, executes a program loaded into the memory device 30B and, in accordance with the instructions of the program, realizes various functions of the controller 30. The interface device 30D functions, for example, as a communication interface for connecting to a communication line inside the shovel 100. The interface device 30D may include a plurality of different types of communication interfaces according to the type of communication line to be connected.

[0064] The interface device 30D also functions as an external interface for reading data from a recording medium and writing data to a recording medium. The recording medium is, for example, a dedicated tool connected to a connector installed inside the cabin 10 via a detachable cable. The recording medium may also be a general-purpose recording medium, such as an SD memory card or a USB (Universal Serial Bus) memory. As a result, a program for realizing various functions of the controller 30 may be provided by, for example, a portable recording medium and installed in the auxiliary storage device 30A of the controller 30. The program may also be downloaded from another computer external to the excavator 100 via the communication device 60 and installed in the auxiliary storage device 30A.

[0065] Note that some of the functions of the controller 30 may be realized by another controller (control device). That is, the functions of the controller 30 may be realized in a distributed manner by a plurality of controllers mounted on the shovel 100.

[0066] The operating pressure sensor 29 detects the pilot pressure on the secondary side (pilot line 27A) of the hydraulic pilot type operating device 26, i.e., the pilot pressure corresponding to the operating state of each driven element (hydraulic actuator) in the operating device 26. The detection signal of the pilot pressure by the operating pressure sensor 29, which corresponds to the operating state of each driven element (hydraulic actuator HA) in the operating device 26, is taken into the controller 30.

[0067] It should be noted that if the operating device 26 is electric or if the operating device 26 is omitted, the operating pressure sensor 29 is omitted. In these cases, the controller 30 can grasp the operating state of each driven element through the operating device 26 based on the operation signal received from the operating device 26.

[0068] The imaging device 40 captures images of the surroundings of the shovel 100. The imaging device 40 is, for example, a monocular camera. The imaging device 40 may also be a three-dimensional camera (3D camera) that can acquire not only two-dimensional image information but also three-dimensional information including information about the distance to an object shown in the image and the depth of the image, such as a stereo camera, a ToF (Time of Flight) camera, or a depth camera.

[0069] For example, the imaging device 40 includes a plurality of cameras. One camera images the area in front of the upper rotating body 3. Another camera images the area behind the upper rotating body 3. Another camera images the area to the left of the upper rotating body 3. Another camera images the area to the right of the upper rotating body 3. This allows the imaging device 40 to capture an image of the entire circumference of the shovel 100, that is, the range covering an angular direction of 360 degrees, when viewed from above the shovel 100.

[0070] The output data of the imaging device 40 (plurality of cameras) is taken into the controller 30 via a one-to-one communication line or an in-vehicle network. This allows the controller 30 to grasp the situation around the shovel 100, for example, based on the output data of the plurality of cameras. Note that some or all of the plurality of cameras may be omitted. Furthermore, the shovel 100 may be provided with a ranging sensor (also referred to as a "distance sensor") capable of acquiring information indicating the distance to an object around the shovel 100, instead of or in addition to the imaging device 40. The ranging sensor is, for example, a LiDAR (Light Detecting and Ranging), a millimeter-wave radar, an ultrasonic sensor, or the like.

[0071] The sensor S1 is attached to the boom 4 and measures the attitude of the boom 4. The sensor S1 outputs measurement data representing the attitude of the boom 4. The attitude of the boom 4 is, for example, the attitude angle (hereinafter referred to as "boom angle") around the rotation axis of the base end of the boom 4, which corresponds to the connection part between the boom 4 and the upper rotating body 3. The sensor S1 includes, for example, a rotary potentiometer, a rotary encoder, an acceleration sensor, an angular acceleration sensor, a 6-axis sensor, an IMU (Inertial Measurement Unit), etc. The same may apply to the sensors S2 to S4 below. The sensor S1 may also include a cylinder sensor that detects the extension / retraction position of the boom cylinder 7. The same may apply to the sensors S2 and S3 below. The output of the sensor S1 (measurement data representing the attitude of the boom 4) is input to the controller 30. This allows the controller 30 to grasp the attitude of the boom 4.

[0072] The sensor S2 is attached to the arm 5 and measures the posture of the arm 5. The sensor S2 outputs measurement data that indicates the posture of the arm 5. The posture of the arm 5 is, for example, the posture angle (hereinafter referred to as "arm angle") around the rotation axis of the base end of the arm 5, which corresponds to the connection part between the arm 5 and the boom 4. The output of the sensor S2 (measurement data that indicates the posture of the arm 5) is input to the controller 30. This enables the controller 30 to grasp the posture of the arm 5.

[0073] The sensor S3 is attached to the bucket 6 and measures the attitude of the bucket 6. The sensor S3 outputs measurement data that indicates the attitude of the bucket 6. The attitude of the bucket 6 is, for example, the attitude angle around the rotation axis of the base end of the bucket 6 that corresponds to the connection part with the arm 5 (hereinafter referred to as the "bucket angle"). The output of the sensor S3 (measurement data that indicates the attitude of the bucket 6) is input to the controller 30. This enables the controller 30 to grasp the attitude of the bucket 6.

[0074] The sensor S4 measures the attitude state of the machine body of the shovel 100 (for example, the upper rotating body 3). The sensor S4 outputs measurement data representing the attitude state of the machine body of the shovel 100. The attitude state of the machine body of the shovel 100 is, for example, the inclination state of the machine body with respect to a predetermined reference plane (for example, a horizontal plane). For example, the sensor S4 is attached to the upper rotating body 3 and measures the inclination angles of the shovel 100 about two axes in the fore-aft and lateral directions (hereinafter referred to as the "fore-aft inclination angle" and the "lateral inclination angle"). The output of the sensor S4 (measurement data representing the attitude state of the machine body of the shovel 100) is taken into the controller 30. This allows the controller 30 to grasp the attitude state (inclination state) of the machine body (upper rotating body 3).

[0075] The sensor S5 is attached to the upper rotating body 3 and measures the rotation state of the upper rotating body 3. The sensor S5 outputs measurement data that indicates the rotation state of the upper rotating body 3. The sensor S5 measures, for example, the rotation angular velocity and rotation angle of the upper rotating body 3. The sensor S5 includes, for example, a gyro sensor, a resolver, a rotary encoder, etc. The output of the sensor S5 (measurement data that indicates the rotation state of the upper rotating body 3) is input to the controller 30. This allows the controller 30 to grasp the rotation state of the upper rotating body 3, such as the rotation angle.

[0076] The controller 30 can grasp (estimate) the position of the tip end (bucket 6) of the attachment AT based on the outputs of the sensors S1 to S5. If the sensor S4 includes a gyro sensor, a six-axis sensor, an IMU, or the like that can detect angular velocity around three axes, the rotation state (e.g., rotation angular velocity) of the upper rotating body 3 may be detected based on the detection signal of the sensor S4. In this case, the sensor S5 may be omitted.

[0077] The sensor S6 measures the position of the shovel 100. The sensor S6 may measure the position in world (global) coordinates, or may measure the position in local coordinates at the work site. In the former case, the sensor S6 is, for example, a GNSS (Global Navigation Satellite System) sensor. In the latter case, the sensor S6 is a transceiver that communicates with equipment that serves as a reference for the position at the work site and is capable of outputting a signal corresponding to the position relative to the reference. The output of the sensor S6 is taken into the controller 30.

[0078] Sensor S7 measures the pressure (cylinder pressure) in the oil chamber of boom cylinder 7. Sensor S7 includes, for example, a sensor that measures the cylinder pressure (rod pressure) in the oil chamber formed on the rod side of boom cylinder 7, and a sensor that measures the cylinder pressure (bottom pressure) in the oil chamber formed on the bottom side. The output of sensor S7 (i.e., measurement data of the cylinder pressure of boom cylinder 7) is taken into controller 30.

[0079] The sensor S8 measures the pressure (cylinder pressure) of the oil chamber of the arm cylinder 8. The sensor S8 includes, for example, a sensor that measures the cylinder pressure (rod pressure) of the oil chamber formed on the rod side of the arm cylinder 8, and a sensor that measures the cylinder pressure (bottom pressure) of the oil chamber formed on the bottom side of the arm cylinder 8. The output of the sensor S8 (i.e., the measurement data of the cylinder pressure of the arm cylinder 8) is taken into the controller 30.

[0080] The sensor S9 measures the pressure (cylinder pressure) of the oil chamber of the bucket cylinder 9. The sensor S9 includes, for example, a sensor that measures the cylinder pressure (rod pressure) of the oil chamber formed on the rod side of the bucket cylinder 9, and a sensor that measures the cylinder pressure (bottom pressure) of the oil chamber formed on the bottom side of the bucket cylinder 9. The output of the sensor S9 (i.e., the measurement data of the cylinder pressure of the bucket cylinder 9) is taken into the controller 30.

[0081] The controller 30 can grasp the load state acting on the attachment AT based on the outputs of the sensors S7 to S9. The load acting on the attachment AT includes, for example, the reaction force acting on the bucket 6 from the soil on the ground being worked on, the weight of the soil contained in the bucket 6, and the like. Note that some or all of the sensors S1 to S9 may be omitted depending on necessity. The shovel 100 may be equipped with other sensors capable of grasping the state of the shovel 100. For example, the shovel 100 may be equipped with a direction sensor capable of detecting its own direction. The direction sensor is, for example, an electronic compass including a geomagnetic sensor.

[0082] Next, an example of the end attachment replacement function of the shovel 100 will be described with reference to FIGS. 3 to 6 in addition to FIGS. 1 and 2.

[0083] Fig. 3 is a functional block diagram of the controller 30 of the shovel 100. Fig. 4 is a flow chart illustrating an example of a method for replacing an end attachment according to this embodiment. Fig. 5 is a process chart illustrating an example of a method for replacing an end attachment. Fig. 6 is an image diagram showing an example of a guidance image GG displayed on a display device included in the output device 50 of the shovel 100.

[0084] 3, the controller 30 of the excavator 100 includes, for example, an operation amount acquisition unit 301, an information acquisition unit 302, an attitude calculation unit 303, a mode acquisition unit 304, a target acquisition unit 305, a control signal generation unit 306, and a guidance generation unit 307. These units of the controller 30 represent the functions of the controller 30 that are realized, for example, by a program installed in the auxiliary storage device 30A being loaded into the memory device 30B and executed by the CPU 30C.

[0085] The operation amount obtaining unit 301 obtains, for example, a detection signal of a pilot pressure corresponding to the operation state of the operation device 26 detected by the operation pressure sensor 29. Furthermore, if the operation device 26 is an electric type, the operation amount obtaining unit 301 obtains an operation signal corresponding to the operation state of the operation device 26 from the operation device 26. The operation amount obtaining unit 301 outputs, for example, to the control signal generating unit 306, the operation amount of the operation device 26 based on the obtained detection signal or operation signal.

[0086] The information acquisition unit 302 acquires, for example, the detection results of sensors S1 to S9. More specifically, the information acquisition unit 302 acquires, for example, the boom angle θ1, the arm angle θ2, the bucket angle θ3, the front-to-rear and left-to-right inclination angles of the excavator 100, the swing angular velocity and swing angle of the upper swing body 3, etc. as the detection results of sensors S1 to S5. In addition, the information acquisition unit 302 acquires, for example, the position of the excavator 100, the cylinder pressure of the boom cylinder 7, the cylinder pressure of the arm cylinder 8, the cylinder pressure of the bucket cylinder 9, etc. as the detection results of sensors S6 to S9. The information acquisition unit 302 outputs the acquired detection results to the attitude calculation unit 303.

[0087] The attitude calculation unit 303 calculates the attitude of the attachment AT based on, for example, the boom angle θ1, arm angle θ2, bucket angle θ3, the front-to-back tilt angle and left-to-right tilt angle of the excavator 100, etc. input from the information acquisition unit 302. The attitude calculation unit 303 may also calculate the load state of the attachment AT based on, for example, the attitude of the attachment AT and the cylinder pressures of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 input from the information acquisition unit 302. The attitude calculation unit 303 outputs the calculated attitude and load state of the attachment AT to, for example, the control signal generation unit 306 and the guidance generation unit 307.

[0088] The mode acquisition unit 304 acquires, for example, the control mode of the shovel 100 input by the operator of the shovel 100 via the input device 52. The control modes of the shovel 100 include, for example, a normal mode and an end attachment exchange mode. The control modes of the shovel 100 may also include, for example, a traveling mode, a payload (weighing) mode, a machine control-machine guidance (MC-MG) mode, a calibration mode, etc. The mode acquisition unit 304 outputs the acquired control mode to the target acquisition unit 305, for example.

[0089] The target acquisition unit 305 acquires the target posture of the attachment AT, for example, in accordance with the control mode input from the mode acquisition unit 304. Specifically, when the control mode input from the mode acquisition unit 304 is the end attachment exchange mode, the target acquisition unit 305 acquires a predetermined posture of the attachment AT stored in advance in the auxiliary storage device 30A or the like as the target posture of the attachment AT.

[0090] The predetermined posture of the attachment AT acquired by the target acquisition unit 305 in the end attachment replacement mode includes, for example, a first posture PS1 of the attachment AT in which the load acting on the first pin P1 or the second pin P2 due to the weight of the end attachment is equal to or less than a predetermined threshold. The first posture PS1 of the attachment AT is stored in the auxiliary storage device 30A, for example, for each type of end attachment.

[0091] The load threshold is set to a load that allows a worker to easily remove the first pin P1 or the second pin P2 with that load acting on it. More specifically, the load threshold can be set to a load that allows a standard worker to manually remove the first pin P1 or the second pin P2 with that load acting on it without using a tool such as a hammer. The load threshold includes, for example, a minimum value of the load acting on the first pin P1 or the second pin P2 due to the weight of the end attachment. This minimum load value may be zero. In this case, the load acting on the first pin P1 or the second pin P2 is only the load due to the weight of the first pin P1 or the second pin P2.

[0092] The load acting on the first pin P1 or the second pin P2 due to the weight of the end attachment may be measured using a sensor such as a strain gauge, but is not necessarily required. If the load is not measured, for example, a posture of the attachment AT that allows a worker to easily remove the first pin P1 or the second pin P2 may be stored in the auxiliary storage device 30A as the first posture PS1 of the attachment AT. This ensures that when the attachment AT is made to assume the first posture PS1, the load acting on the first pin P1 or the second pin P2 due to the weight of the end attachment will be equal to or less than a threshold value.

[0093] In the example shown in FIG. 5 , the first attitude PS1 of the attachment AT is an attitude of the attachment AT in which the load acting on the first pin P1 due to the weight of the bucket 6 is below a threshold value at which the first pin P1 can be easily removed. Specifically, for example, when the attachment AT takes the first attitude PS1, the center of gravity GC of the bucket 6 is positioned directly below the second pin P2. In other words, when the attachment AT takes the first attitude PS1, for example, the link pin Lp, which is the second pin P2, and the center of gravity GC of the bucket 6 are aligned vertically. In other words, the first attitude PS1 of the attachment AT is an attitude in which, for example, the center of gravity GC of the end attachment is positioned directly below the second pin P2, and the load acting on the second pin P2 due to the weight of the bucket 6 is maximized. The center of gravity GC of the end attachment can be calculated based on the dimensions of the end attachment.

[0094] 5, when the attachment AT takes the first posture PS1, the second link L2 of the link mechanism L, which is rotatably connected to the bucket 6 via the second pin P2, is aligned in the vertical direction. Specifically, the second link L2 of the link mechanism L is generally parallel to the vertical direction. As a result, the second link L2 of the link mechanism L, the second pin P2 connecting the second link L2 to the bucket 6, and the center of gravity GC of the bucket 6 are aligned in a straight line in the vertical direction.

[0095] That is, the first orientation PS1 of the attachment AT is, for example, an orientation in which the second link L2 of the link mechanism L, the second pin P2, and the center of gravity GC of the end attachment are aligned in a vertical line. More specifically, the first orientation PS1 of the attachment AT is an orientation in which, for example, the load acting on the second pin P2 due to the weight of the end attachment is at its maximum, and the second link L2 of the link mechanism L attached to the end attachment via the second pin P2 is aligned in the vertical direction. In this state, the load acting on the first pin P1 due to the weight of the end attachment is below a threshold value that makes it easy to remove the first pin P1.

[0096] Furthermore, in the example shown in FIG. 5, when the attachment AT takes the first position PS1, the toe of the lower end of the bucket 6 is spaced from the ground surface GS. That is, the first position PS1 of the attachment AT is a position in which there is a space between the lower end of the end attachment and the ground surface GS. The space between the lower end of the end attachment and the ground surface GS is not particularly limited, but is, for example, approximately 50 mm. As a result, no reaction force from the ground surface GS acts on the end attachment, and only the load due to the end attachment's own weight acts on the first pin P1 and the second pin P2. Furthermore, since the second pin P2 bears almost all of the load due to the end attachment's own weight, the load acting on the first pin P1 due to the end attachment's own weight is minimized and approaches zero as much as possible.

[0097] Furthermore, the predetermined posture of the attachment AT acquired by the target acquisition unit 305 in the end attachment replacement mode includes, for example, the second posture PS2 of the attachment AT shown in FIG. 5. The second posture PS2 of the attachment AT is based on, for example, a state in which the first pin P1 has been removed from the attachment AT in the first posture PS1. The second posture PS2 of the attachment AT is, for example, a posture of the attachment AT in which the support member BM is positioned below the center of gravity GC of the bucket 6, which is the end attachment, and the weight of the bucket 6 is supported by the support member BM. The support member BM is not particularly limited as long as it can support the weight of the end attachment, but for example, steel materials such as angles that can be procured at the work site can be used.

[0098] The position of the support member BM below the center of gravity GC of the end attachment when the attachment AT is in the second position PS2 includes the position directly below the center of gravity GC. The position of the support member BM may be shifted from directly below the center of gravity GC of the end attachment as long as the end attachment does not touch the ground when the attachment AT is in the second position PS2. In the example shown in Figure 5, when the attachment AT is in the second position PS2, the bottom surface of the bucket 6 is supported by the support member BM without coming into contact with the ground surface GS, and there is a gap between the bottom surface and the ground surface GS.

[0099] As shown in FIG. 3, the target acquisition unit 305 outputs, for example, the first attitude PS1 and the second attitude PS2 of the attachment AT acquired from the auxiliary storage device 30A to the control signal generation unit 306 and the guidance generation unit 307.

[0100] The control signal generating unit 306 receives, for example, the control mode selected by the operator of the excavator 100, the target attitude of the attachment AT, and the operation amount of the operating device 26. Based on these inputs, the control signal generating unit 306 generates a control signal for driving the hydraulic actuator HA and outputs it to the hydraulic control valve 31 and the hydraulic control valve 33.

[0101] The guidance generation unit 307 outputs a control signal for causing a display device included in the output device 50 to display a guidance image GG, for example, based on the current attitude and target attitude of the attachment AT input from the attitude calculation unit 303 and the target acquisition unit 305. The guidance generation unit 307 may also generate a control signal for causing a speaker included in the output device 50 to output sound, for example.

[0102] 6, the guidance image GG includes, for example, an image that visually shows the boom angle θ1, the arm angle θ2, and the bucket angle θ3 in association with an image of the excavator 100 that includes the attachment AT. The guidance image GG may also include, for example, a table that shows the target angles θ1t, θ2t, θ3t, current angles θ1c, θ2c, θ3c, and angle differences θ1d, θ2d, θ3d of the boom angle θ1, arm angle θ2, and bucket angle θ3 that correspond to the first posture PS1 and the second posture PS2, which are the target postures.

[0103] Next, the replacement direction of the end attachment of this embodiment will be described along with an example of processing by the controller 30 of the shovel 100 according to this embodiment.

[0104] For example, when the controller 30 starts the processing flow shown in FIG. 4, it executes processing P01 for acquiring the control mode and processing P02 for determining whether the control mode is the attachment exchange mode.

[0105] In process P01, the mode acquisition unit 304 of the controller 30 accepts input of a control mode by the user of the shovel 100, for example, via the input device 52. Furthermore, in this process P01, the mode acquisition unit 304 may also accept, for example, selection of manual operation or machine control-machine guidance (MC-MG) in the control mode along with input of the control mode by the user of the shovel 100.

[0106] In process P02, if the mode acquisition unit 304 determines that the input control mode is not the attachment exchange mode (NO), it ends the process flow shown in Fig. 4. Thereafter, the controller 30 starts another process flow corresponding to the input control mode.

[0107] On the other hand, when the operator of the excavator 100 selects the attachment change mode via the input device 52 in process P01, the mode acquisition unit 304 determines in process P02 that the selected control mode is the attachment change mode (YES). Then, the controller 30 executes process P11 to acquire the first attitude PS1 of the attachment AT.

[0108] In this process P11, the target acquisition unit 305 of the controller 30 acquires, for example, the first attitude PS1 of the attachment AT stored in the auxiliary storage device 30A, and outputs it to the control signal generation unit 306 and the guidance generation unit 307. Thereafter, the controller 30 executes, for example, a process P12 for making the attachment AT take the first attitude PS1, and a process P13 for determining whether the current attitude of the attachment AT is the first attitude PS1.

[0109] For example, suppose that in the above-mentioned process P01, the operator of the excavator 100 selects manual control when selecting the attachment change mode. In this case, in process P12, the guidance generation unit 307 generates, for example, a control signal for displaying a guidance image GG showing the first position PS1 of the attachment AT, and outputs it to a display device included in the output device 50. The guidance generation unit 307 also generates, for example, a control signal for outputting audio guidance to guide the operator to take the first position PS1 of the attachment AT, and outputs it to a speaker included in the output device 50.

[0110] Also, in this process P12, the operator of the excavator 100 operates the operating device 26 while referring to the guidance image GG displayed on the display device of the output device 50 and listening to the audio guidance output from the speaker, to cause the attachment AT to take the first posture PS1 shown in Fig. 5. The posture calculation unit 303 of the controller 30 outputs, for example, the current posture of the attachment AT to the guidance generation unit 307.

[0111] Then, in process P13, the guidance generation unit 307, for example, compares the current posture of the attachment AT with the first posture PS1 and determines whether or not the current posture of the attachment AT satisfies the first posture PS1. In this process P13, if the guidance generation unit 307 determines, for example, that the current posture of the attachment AT does not satisfy the first posture PS1 (NO), it executes process P12 again and changes the guidance image GG and audio guidance according to the current posture of the attachment AT.

[0112] On the other hand, in process P13, if the guidance generating unit 307 determines that the current posture of the attachment AT satisfies the first posture PS1 (YES), it executes process P14, which prompts the removal of the first pin P1. In this process P14, the guidance generating unit 307 outputs, for example, via the output device 50, a guidance image GG or audio guidance indicating that the attachment AT satisfies the first posture PS1 and that the first pin P1 can be removed.

[0113] This allows the operator of the shovel 100 or a worker around the shovel 100 to remove the first pin P1 (bucket pin 6p) from the attachment AT that has assumed the first posture PS1, as shown in FIG. 5. At this time, the load due to the weight of the bucket 6 acting on the second pin P2 (link pin Lp) is at its maximum, and almost no load due to the weight of the bucket 6 acts on the first pin P1. In addition, because there is a gap between the bucket 6 and the ground surface GS, no radial force caused by the bucket 6 being pressed against the ground surface GS acts on the first pin P1. This allows the operator or worker to easily and safely remove the first pin P1.

[0114] Also, for example, suppose that in the above-mentioned process P01, the operator of the excavator 100 selects MC-MG when selecting the attachment exchange mode. In this case, in process P12, the control signal generation unit 306 generates, for example, a control signal for causing the attachment AT to assume the first position PS1, and outputs it to the hydraulic control valve 31 or the hydraulic control valve 33. Furthermore, the guidance generation unit 307 generates, for example, a control signal for outputting a guidance image GG or audio guidance notifying that the attachment AT will automatically assume the first position PS1, and outputs it to the display device or speaker of the output device 50.

[0115] Then, in process P13, the control signal generating unit 306, for example, compares the current posture of the attachment AT with the first posture PS1 and determines whether or not the current posture of the attachment AT satisfies the first posture PS1. In this process P13, if the control signal generating unit 306 determines, for example, that the current posture of the attachment AT does not satisfy the first posture PS1 (NO), it executes process P12 again and brings the posture of the attachment AT closer to the first posture PS1.

[0116] On the other hand, in process P13, if the control signal generating unit 306 determines that the current posture of the attachment AT satisfies the first posture PS1 (YES), it stops the operation of the attachment AT. Also, the guidance generating unit 307 executes process P14, for example, and outputs a guidance image GG and audio guidance via the output device 50, indicating that the attachment AT satisfies the first posture PS1 and that the first pin P1 can be removed.

[0117] The operator of the excavator 100 or a nearby worker removes the first pin P1 from the attachment AT that has taken the first attitude PS1, for example, by following the guidance image GG or audio guidance. Thereafter, when the operator inputs via the input device 52 that the removal of the first pin P1 has been completed, the controller 30 executes, for example, a process P21 for acquiring the second attitude PS2 of the attachment AT.

[0118] In this process P21, the target acquisition unit 305 of the controller 30 acquires, for example, the second attitude PS2 of the attachment AT stored in the auxiliary storage device 30A, and outputs it to the control signal generation unit 306 and the guidance generation unit 307. Thereafter, the controller 30 executes, for example, a process P22 for making the attachment AT take the second attitude PS2, and a process P23 for determining whether the current attitude of the attachment AT is the second attitude PS2.

[0119] In the example shown in FIG. 5, the controller 30 executes, for example, processing in steps P22 and P23 to make the attachment AT assume the second preliminary position PS2A and then the second position PS2.

[0120] For example, suppose that in the above-mentioned process P01, the operator of the excavator 100 selects manual control when selecting the attachment change mode. In this case, in process P22, the guidance generating unit 307 generates, for example, a control signal for displaying a guidance image GG showing the second preliminary position PS2A of the attachment AT, and outputs the control signal to a display device included in the output device 50. The guidance generating unit 307 also generates, for example, a control signal for outputting audio guidance to guide the operator to take the second preliminary position PS2A of the attachment AT, and outputs the control signal to a speaker included in the output device 50.

[0121] Also, in this process P22, the operator of the excavator 100 operates the operating device 26 while referring to the guidance image GG displayed on the display device of the output device 50 and listening to the audio guidance output from the speaker, to cause the attachment AT to assume the preliminary second posture PS2A shown in Fig. 5. The posture calculation unit 303 of the controller 30 outputs, for example, the current posture of the attachment AT to the guidance generation unit 307.

[0122] Then, in process P23, the guidance generating unit 307, for example, compares the current attitude of the attachment AT with the preliminary second attitude PS2A and determines whether or not the current attitude of the attachment AT satisfies the preliminary second attitude PS2A. In this process P23, if the guidance generating unit 307 determines, for example, that the current attitude of the attachment AT does not satisfy the preliminary second attitude PS2A (NO), it executes process P22 again and changes the guidance image GG and audio guidance according to the current attitude of the attachment AT.

[0123] On the other hand, in process P23, if the guidance generating unit 307 determines that the current posture of the attachment AT satisfies the preliminary second posture PS2A (YES), for example, the process returns to process P22 and executes the process of causing the attachment AT to assume the second posture PS2. At this time, the guidance generating unit 307 outputs, via the output device 50, a guidance image GG or audio guidance indicating that the attachment AT satisfies the preliminary second posture PS2A shown in FIG. 5 and that it is possible to position the support member BM.

[0124] As shown in Fig. 5, the second preliminary position PS2A of the attachment AT is a position during transition from the first position PS1 to the second position PS2. In the second preliminary position PS2A of the attachment AT, the bucket 6 has the first pin P1 (bucket pin 6p) removed, the toe of the bucket 6 is in contact with the ground, and there is a gap below the center of gravity GC. This allows the operator of the excavator 100 or a worker near the excavator 100 to place a support member BM, such as an angle, below the center of gravity GC of the bucket 6, which is the end attachment of the attachment AT in the second preliminary position PS2A.

[0125] For example, when the operator of the excavator 100 inputs via the input device 52 that the placement of the support member BM has been completed, the guidance generating unit 307 executes a process P22 for causing the attachment AT to assume the second position PS2. In this process P22, the guidance generating unit 307 generates a control signal for displaying a guidance image GG showing the second position PS2 of the attachment AT, and outputs this to a display device included in the output device 50. The guidance generating unit 307 also generates a control signal for outputting audio guidance for causing the operator to assume the second position PS2 of the attachment AT, and outputs this to a speaker included in the output device 50.

[0126] Also, in this process P22, the operator of the excavator 100 operates the operating device 26 to cause the attachment AT to assume the second attitude PS2 shown in FIG. 5 while referring to the guidance image GG displayed on the display device of the output device 50 and listening to the audio guidance output from the speaker. The attitude calculation unit 303 of the controller 30 outputs, for example, the current attitude of the attachment AT to the guidance generation unit 307. The operator of the excavator 100 balances the bucket 6 on the support member BM, for example, by finally lowering the boom 4 and moving the arm 5 in the direction of arrow A1, thereby forming a gap between the ground surface GS and the bucket 6.

[0127] Then, in process P23, the guidance generation unit 307, for example, compares the current posture of the attachment AT with the second posture PS2 and determines whether or not the current posture of the attachment AT satisfies the second posture PS2. In this process P23, if the guidance generation unit 307 determines, for example, that the current posture of the attachment AT does not satisfy the second posture PS2 (NO), it executes process P22 again and changes the guidance image GG and audio guidance according to the current posture of the attachment AT.

[0128] On the other hand, in process P23, if the guidance generating unit 307 determines that the current posture of the attachment AT satisfies the second posture PS2 (YES), it executes process P24 to prompt the removal of the second pin P2. In this process P24, the guidance generating unit 307 outputs, for example, via the output device 50, a guidance image GG or audio guidance indicating that the attachment AT satisfies the second posture PS2 and that the removal of the second pin P2 is possible.

[0129] As a result, the operator of the shovel 100 or a worker around the shovel 100 can interpose the stopper ST for preventing tipping between the bucket 6 of the attachment AT in the second position PS2 and the ground surface GS, and remove the second pin P2 (link pin Lp), for example, as shown in Figure 5. At this time, the weight of the bucket 6, which is the end attachment, is supported almost entirely by the support member BM, and a gap is formed between the ground surface GS and the bucket 6.

[0130] Therefore, the second pin P2 is hardly subjected to a load due to the weight of the bucket 6. Furthermore, for example, radial force caused by the bucket 6 being pressed against the ground surface GS is not applied to the second pin P2. Therefore, an operator or worker can easily and safely remove the second pin P2. The stopper ST is not particularly limited as long as it can prevent the bucket 6 from tipping over, and a piece of lumber or the like that can be procured at the work site can be used. Furthermore, by interposing the stopper ST and the support member BM between the end attachment and the ground surface GS, it becomes easier to transport the end attachment, for example, by a forklift.

[0131] Also, for example, suppose that in the above-mentioned process P01, the operator of the excavator 100 selects MC-MG when selecting the attachment change mode. In this case, in process P22, the control signal generation unit 306 generates, for example, a control signal for causing the attachment AT to assume the second preliminary position PS2A or the second position PS2, and outputs the control signal to the hydraulic control valve 31 or the hydraulic control valve 33. Furthermore, the guidance generation unit 307 generates, for example, a control signal for outputting a guidance image GG or audio guidance notifying the operator that the attachment AT will automatically assume the second preliminary position PS2A or the second position PS2, and outputs the control signal to the display device or speaker of the output device 50.

[0132] Then, in process P23, the control signal generating unit 306, for example, compares the current posture of the attachment AT with the preliminary second posture PS2A or the second posture PS2, and determines whether the current posture of the attachment AT satisfies the preliminary second posture PS2A or the second posture PS2. In this process P23, if the control signal generating unit 306 determines, for example, that the current posture of the attachment AT does not satisfy the preliminary second posture PS2A or the second posture PS2 (NO), it executes process P22 again and brings the attachment AT closer to the preliminary second posture PS2A or the second posture PS2.

[0133] On the other hand, in process P23, if the control signal generating unit 306 determines that the current posture of the attachment AT satisfies the preliminary second posture PS2A or the second posture PS2 (YES), it stops the operation of the attachment AT. Also, for example, after the posture of the attachment AT satisfies the second posture PS2, the guidance generating unit 307 executes the above-mentioned process P24 and outputs a guidance image GG or audio guidance via the output device 50, indicating that the second pin P2 can be removed.

[0134] Thereafter, the operator of the excavator 100 or a nearby worker follows, for example, the guidance image GG or the audio guidance to remove the second pin P2 from the attachment AT that has taken the second posture PS2.

[0135] In process P24, for example, when the operator of the shovel 100 inputs via the input device 52 that removal of the second pin P2 has been completed, the controller 30 ends, for example, the process flow shown in Fig. 4 and terminates the attachment replacement mode. Thereafter, the operator of the shovel 100 operates, for example, the operating device 26 to cause the attachment AT to take the standby second posture PS2P as shown in Fig. 5, thereby separating the bucket 6 from the link mechanism L, and performs the task of replacing the bucket 6 with another end attachment.

[0136] In the example shown in Figure 5, the first position PS1 of the attachment AT is described as a position in which the load acting on the second pin P2 due to the weight of the end attachment is at its maximum. However, the first position PS1 of the attachment AT may also be a position in which the load acting on the first pin P1 due to the weight of the end attachment is at its maximum. Specifically, the first position PS1 of the attachment AT may be, for example, a position in which the center of gravity GC of the end attachment is located directly below the first pin P1. This makes it possible to easily remove the second pin P2 from the attachment AT in the first position PS1.

[0137] As described above, the excavator 100 of this embodiment includes the lower traveling body 1, the upper rotating body 3 rotatably mounted on the lower traveling body 1, the attachment AT mounted on the upper rotating body 3, and the controller 30 that acquires the attitude of the attachment AT. The attachment AT has an end attachment such as a bucket 6 rotatably mounted via a first pin P1, and a link mechanism L that is attached to the end attachment via a second pin P2 and rotates the end attachment. The controller 30 has an end attachment exchange mode that acquires a first attitude PS1 of the attachment AT in which the load acting on the first pin P1 or the second pin P2 due to the weight of the end attachment is equal to or less than a threshold.

[0138] With this configuration, the excavator 100 of this embodiment can cause the attachment AT to assume the first posture PS1 as shown in FIG. 5 using the guidance image GG or audio guidance generated by the controller 30, or the MC-MG by the controller 30. As a result, for example, the second pin P2 and the center of gravity GC of the bucket 6 are aligned vertically. This causes almost all of the load due to the weight of the end attachment, such as the bucket 6, to act on the second pin P2, and the load due to the weight of the end attachment acting on the first pin P1 can be reduced to or below a threshold value that makes it easy to remove the first pin P1, and can be brought as close to zero as possible. This makes it easy for an operator or worker to remove the first pin P1, and makes it easy to replace the end attachment.

[0139] Furthermore, as described above, the first posture of the attachment AT may be a posture in which the load acting on the second pin P2 is equal to or less than a threshold value. In this case, for example, the first pin P1 and the center of gravity GC of the bucket 6 are aligned vertically. This causes almost all of the load due to the weight of the end attachment, such as the bucket 6, to act on the first pin P1, and the load acting on the second pin P2 due to the weight of the end attachment can be reduced to or less than a threshold value that makes it easy to remove the second pin P2, and can be brought as close to zero as possible. This makes it easy for an operator or worker to remove the second pin P2, and makes it easy to replace the end attachment.

[0140] Furthermore, in the excavator 100 of this embodiment, in the end attachment replacement mode, the controller 30 acquires a first attitude PS1 of the attachment AT. The first attitude PS1 of the attachment AT is an attitude in which the load acting on the second pin P2 due to the weight of the end attachment such as the bucket 6 is at its maximum, and the second link L2 of the link mechanism L attached to the end attachment such as the bucket 6 via the second pin P2 is aligned in the vertical direction.

[0141] With this configuration, by causing the attachment AT to take the first posture PS1, the second link L2 of the link mechanism L, the second pin P2, and the center of gravity GC of the end attachment such as the bucket 6 can be aligned in a vertical line, as shown in Figure 5. This allows the first pin P1, such as the bucket pin 6p that rotatably connects the end attachment to the tip of the arm 5, to be removed while the end attachment such as the bucket 6 is stably supported by the link mechanism L.

[0142] Furthermore, in the end attachment replacement mode of the excavator 100 of this embodiment, the controller 30 acquires the second attitude PS2 of the attachment AT as shown in Fig. 5. The second attitude PS2 of the attachment AT is an attitude in which the first pin P1 is removed from the attachment AT and the support member BM is positioned below the center of gravity GC of the end attachment, such as the bucket 6, and the weight of the end attachment is supported by the support member BM.

[0143] With this configuration, most of the weight of the end attachment, such as the bucket 6, can be supported by the support member BM. As a result, the load due to the weight of the end attachment acting on the second pin P2, which rotatably connects the second link L2 of the link mechanism L to the end attachment, and the load due to the end attachment being pressed against the ground surface GS, can be reduced as close to zero as possible. This makes it easy for an operator or worker to remove the second pin P2, making it easy to replace the end attachment.

[0144] In the excavator 100 of this embodiment, the first posture PS1 is a posture in which there is a gap between an end attachment such as the bucket 6 and the ground surface GS.

[0145] With this configuration, when the attachment AT assumes the first posture PS1, no reaction force from the ground surface GS acts on the end attachment, and only the load due to the end attachment's own weight acts on the first pin P1 and the second pin P2. Furthermore, since the second pin P2 bears almost all of the load due to the end attachment's own weight, the load acting on the first pin P1 due to the end attachment's own weight is minimized and approaches zero as much as possible. Similarly, since the first pin P1 bears almost all of the load due to the end attachment's own weight, the load acting on the second pin P2 due to the end attachment's own weight is minimized and approaches zero as much as possible. Therefore, simply by adjusting the position of the second pin P2 or the first pin P1 and the position of the center of gravity GC of the end attachment, the load acting on the first pin P1 or the second pin P2 due to the end attachment's own weight can be minimized. Therefore, the excavator 100 of this embodiment makes it easy for an operator to remove the first pin P1 or the second pin P2.

[0146] Moreover, the excavator 100 that is the target of the end attachment replacement method according to this embodiment includes a lower traveling body 1, an upper rotating body 3 that is rotatably mounted on the lower traveling body 1, and an attachment AT that is mounted on the upper rotating body 3. The attachment AT has an end attachment such as a bucket 6 that is rotatably mounted via a first pin P1, and a link mechanism L that is attached to the end attachment via a second pin P2 and rotates the end attachment. As shown in FIG. 4 , the end attachment replacement method according to this embodiment includes a step P12 of causing the attachment AT to assume a first position PS1 in which the load acting on the first pin P1 or the second pin P2 due to the weight of the end attachment is equal to or less than a threshold value.

[0147] By performing step P12, the attachment AT is brought into the first position PS1 as shown in FIG. 5, so that the second pin P2 and the center of gravity GC of the bucket 6 are aligned vertically. This causes almost all of the load due to the weight of the end attachment, such as the bucket 6, which is spaced from the ground surface GS, to act on the second pin P2. As a result, the load acting on the first pin P1 due to the end attachment's own weight and the load caused by the end attachment being pressed against the ground surface GS can be reduced to or below a threshold value at which the first pin P1 can be easily removed, and can be reduced to as close to zero as possible. Therefore, the attachment replacement method of this embodiment makes it easy for an operator or worker to remove the first pin P1, making it possible to easily replace the end attachment.

[0148] Furthermore, as described above, the first posture of the attachment AT may be a posture in which the load acting on the first pin P1 is equal to or less than a threshold value. In this case, for example, the first pin P1 and the center of gravity GC of the bucket 6 are aligned vertically. This causes almost all of the load due to the weight of the end attachment, such as the bucket 6, to act on the first pin P1. As a result, the load acting on the second pin P2 due to the weight of the end attachment and the load caused by the end attachment being pressed against the ground surface GS can be reduced to or less than a threshold value at which the second pin P2 can be easily removed, and can be reduced to as close to zero as possible. This makes it easy for an operator or worker to remove the second pin P2, and makes it possible to easily replace the end attachment.

[0149] The end attachment replacement method of this embodiment also includes a step P12 of placing the attachment AT in a first position PS1. The first position PS1 of the attachment AT is a position in which the load acting on the second pin due to the weight of the end attachment, such as the bucket 6, is maximized and the second link L2 of the link mechanism L attached to the end attachment via the second pin P2 is parallel to the vertical direction.

[0150] By causing the attachment AT to take the first attitude PS1 through step P12, the second link L2 of the link mechanism L, the second pin P2, and the center of gravity GC of the end attachment such as the bucket 6 can be aligned in a vertical line, as shown in Fig. 5. This allows the first pin P1, such as the bucket pin 6p that rotatably connects the end attachment to the tip of the arm 5, to be removed while the end attachment such as the bucket 6 is stably supported by the link mechanism L.

[0151] Furthermore, the method for replacing an end attachment in this embodiment includes a step P22 of causing the attachment AT to assume a second position PS2, as shown in Fig. 4. The second position PS2 of the attachment AT is a position in which the first pin P1 is removed from the attachment AT and the support member BM is positioned below the center of gravity GC of the end attachment, such as the bucket 6, and the weight of the end attachment is supported by the support member BM.

[0152] By performing step P22, most of the weight of the end attachment, such as the bucket 6, can be supported by the support member BM. As a result, the load due to the weight of the end attachment acting on the second pin P2, which rotatably connects the second link L2 of the link mechanism L to the end attachment, and the load due to the end attachment being pressed against the ground surface GS can be reduced as close to zero as possible. This makes it easy for an operator or worker to remove the second pin P2, making it easy to replace the end attachment.

[0153] As described above, according to this embodiment, it is possible to provide a shovel 100 that allows easy replacement of an end attachment, and a method for replacing an end attachment. Note that the shovel and the method for replacing an end attachment according to the present disclosure are not limited to the above-described embodiment. Below, a modified example of the above-described embodiment will be described with reference to FIG. 7 and with reference to FIGS. 1 to 6.

[0154] Figure 7 is a process diagram illustrating a modified example of the method for replacing the shovel 100 and end attachment of the aforementioned embodiment 1. The method for replacing the shovel 100 and end attachment of this modified example differs from the method for replacing the shovel 100 and end attachment of the aforementioned embodiment 1 mainly in that the end attachment is changed from the bucket 6 to a grapple 6G. Therefore, in Figure 7, the same parts as those of the aforementioned embodiment 1 are designated by the same reference numerals, and description thereof will be omitted.

[0155] In the shovel 100 of this modified example, the controller 30 has an end attachment replacement mode, similar to the shovel 100 of the above-described first embodiment. In the end attachment replacement mode, the controller 30 executes processing to acquire a first orientation PS1, similar to processing P11 shown in Fig. 4. This first orientation PS1 is, for example, as shown in Fig. 7, the orientation of the attachment AT in which the load acting on the first pin P1 due to the weight of the grapple 6G is equal to or less than a threshold value.

[0156] In the first position PS1 of the attachment AT, for example, the four claws 6c of the grapple 6G are spread out in the front, rear, left, and right directions, leaving a gap of approximately 30 mm between the tips of the four claws 6c and the ground surface GS. The four claws 6c of the grapple 6G are opened and closed, for example, by the extension and contraction of a hydraulic cylinder provided in the grapple 6G. The four claws 6c of the grapple 6G are rotated, for example, by the rotation of a hydraulic motor built into the base of the grapple 6G. Hydraulic oil is supplied to the hydraulic cylinder and hydraulic motor of the grapple 6G via, for example, a control valve 17.

[0157] Furthermore, the end attachment replacement method of this modified example includes a step P12 of causing the attachment AT to assume a first position PS1, similar to the method of the first embodiment described above. As a result, as shown in Fig. 7, when the attachment AT assumes the first position PS1, the second pin P2 and the center of gravity of the grapple 6G are positioned along the vertical direction. Furthermore, the second link L2 of the link mechanism L is positioned along the vertical direction and is generally parallel to the vertical direction.

[0158] The controller 30 of the excavator 100 of this modified example executes, for example, in the end attachment replacement mode, a process for acquiring the first standby position PS1P, the second standby position PS2A, and the second position PS2 shown in Fig. 7. These positions are stored in advance in, for example, the auxiliary storage device 30A. Furthermore, the controller 30 executes, for example, a process for causing the attachment AT to assume the first standby position PS1P, the second standby position PS2A, and the second position PS2.

[0159] Specifically, for example, with the attachment AT in the first position PS1, the operator or worker removes the first pin P1, and then slightly closes the arm 5 to cause the attachment AT to assume the first backup position PS1P. As a result, the tip of the rear claw 6c of the front, rear, left, and right claws 6c provided on the grapple 6G comes into contact with the ground surface GS. In this state, the support member BM is placed under the lower ends of the left and right open claws 6c of the grapple 6G. The support member BM is not particularly limited, but can be, for example, a steel plate or scrap metal about 30 mm thick that can be procured at the work site.

[0160] Thereafter, with the lower end of the open claw 6c on the rear side of the grapple 6G remaining on the ground, the arm 5 is closed in the direction of arrow A2, and the second link L2 of the link mechanism L is laid down so that its angle with the horizontal is 45 degrees or less, causing the attachment AT to assume the second preliminary position PS2A.Then, the boom 4 is lowered and the arm 5 is moved in the direction of arrow A3, causing the attachment AT to assume the second position PS2.

[0161] This places the left and right claws 6c of the grapple 6G on the left and right support members BM, forming a gap between the lower ends of the claws 6c of the grapple 6G, which are spread forward and backward, and the ground surface GS. As a result, similar to the second position PS2 of the attachment AT shown in FIG. 5, most of the weight of the grapple 6G, which is an end attachment, can be supported by the left and right support members BM. This reduces to as close as possible to zero the load due to the weight of the grapple 6G acting on the second pin P2, which rotatably connects the second link L2 of the link mechanism L to the grapple 6G, and the load due to the grapple 6G being pressed against the ground surface GS. This makes it easy for an operator or worker to remove the second pin P2, making it possible to easily replace end attachments such as the grapple 6G.

[0162] [Embodiment 2] Next, a second embodiment of the shovel and attachment replacement method according to the present disclosure will be described with reference to FIGS. 1 to 3 and 6 and with reference to FIGS. 8 and 9.

[0163] Fig. 8 is a flow chart illustrating a method for replacing an end attachment according to the second embodiment, along with the flow of processing by the controller 30 of the shovel 100 according to the second embodiment. Fig. 9 is a process chart illustrating the method for replacing an end attachment according to the second embodiment.

[0164] The shovel 100 and the method for replacing an end attachment of this embodiment differ from the shovel 100 and the method for replacing an end attachment of the above-described first embodiment in that a dummy pin Pd having a smaller diameter than the first pin P1 is used when replacing the end attachment. Other configurations of the shovel 100 and the method for replacing an end attachment of this embodiment are similar to those of the shovel 100 and the method for replacing an end attachment of the above-described first embodiment, and therefore similar parts are denoted by the same reference numerals and description thereof will be omitted.

[0165] When the controller 30 of the excavator 100 of this embodiment starts the processing flow shown in Fig. 8, it executes processing P01 to processing P13 similar to the processing performed by the controller 30 of the first embodiment described above and shown in Fig. 4. When the controller 30 determines in processing P13 that the posture of the attachment AT satisfies the first posture PS1 (YES), it executes processing P15, which prompts the user to replace the first pin P1 with a dummy pin Pd, as shown in Fig. 8.

[0166] In this process P15, the guidance generation unit 307 of the controller 30 outputs, via the output device 50, a guidance image GG or audio guidance indicating, for example, that the attachment AT has fulfilled the first posture PS1 and the first pin P1 can be replaced with a dummy pin Pd.

[0167] The operator of the excavator 100 or a nearby worker, for example, follows the guidance image GG or audio guidance to remove the first pin P1 from the attachment AT that has taken the first posture PS1 shown in Fig. 9 and replace it with a dummy pin Pd that has a smaller diameter than the first pin P1. Thereafter, when the operator inputs via the input device 52 that the replacement of the first pin P1 has been completed, the controller 30 executes, for example, a process P31 for acquiring a third posture PS3 of the attachment AT.

[0168] 9, the third position PS3 of the attachment AT is a position in which the first pin P1 has been replaced with a smaller-diameter dummy pin Pd, the center of gravity GC of an end attachment such as the bucket 6 is located directly below the dummy pin Pd, and the second link L2 of the link mechanism L is aligned vertically. In other words, when the attachment AT takes the third position PS3, the dummy pin Pd and the center of gravity GC of the bucket 6 are aligned in a straight line in the vertical direction, and the second link L2 of the link mechanism L is generally parallel to the vertical direction.

[0169] In process P31, the target acquisition unit 305 of the controller 30 acquires, for example, the third posture PS3 of the attachment AT stored in the auxiliary storage device 30A, and outputs it to the control signal generation unit 306 and the guidance generation unit 307. Thereafter, the controller 30 executes, for example, process P32 to make the attachment AT assume the third posture PS3, and process P33 to determine whether the current posture of the attachment AT is the third posture PS3, as shown in Figure 8.

[0170] For example, suppose that in the above-mentioned process P01, the operator of the excavator 100 selects manual control when selecting the attachment change mode. In this case, in process P32, the guidance generation unit 307 generates, for example, a control signal for displaying a guidance image GG showing the third position PS3 of the attachment AT, and outputs it to a display device included in the output device 50. The guidance generation unit 307 also generates, for example, a control signal for outputting audio guidance to guide the operator to take the third position PS3 of the attachment AT, and outputs it to a speaker included in the output device 50.

[0171] Also, in this process P32, the operator of the excavator 100 operates the operating device 26 while referring to the guidance image GG displayed on the display device of the output device 50 and listening to the audio guidance output from the speaker, to cause the attachment AT to take the third posture PS3 shown in Fig. 9. The posture calculation unit 303 of the controller 30 outputs, for example, the current posture of the attachment AT to the guidance generation unit 307.

[0172] Then, in process P33, the guidance generation unit 307, for example, compares the current posture of the attachment AT with the third posture PS3 and determines whether or not the current posture of the attachment AT satisfies the third posture PS3. In this process P33, if the guidance generation unit 307 determines, for example, that the current posture of the attachment AT does not satisfy the third posture PS3 (NO), it executes process P32 again and changes the guidance image GG and audio guidance according to the current posture of the attachment AT.

[0173] On the other hand, in process P33, if the guidance generating unit 307 determines that the current posture of the attachment AT satisfies the third posture PS3 (YES), it executes process P34, which prompts the removal of the second pin P2. In this process P34, the guidance generating unit 307 outputs, for example, via the output device 50, a guidance image GG or audio guidance indicating that the attachment AT satisfies the third posture PS3 and that the removal of the second pin P2 is possible.

[0174] The operator of the excavator 100 or a nearby worker removes the second pin P2 from the attachment AT in the third position PS3, for example, following the guidance image GG or audio guidance. Thereafter, when the operator inputs via the input device 52 that the removal of the second pin P2 has been completed, the controller 30 executes a process P41 for acquiring the fourth position PS4 of the attachment AT, as shown in FIG. 8, for example.

[0175] As shown in Figure 9, the fourth position PS4 of the attachment AT is a position in which the second pin P2 is removed from the attachment AT and an end attachment such as a bucket 6 is in contact with the ground, creating a gap between the upper end of the dummy pin Pd and the upper end of the pin hole in the end attachment. Specifically, when the attachment AT takes the fourth position PS4, the weight of the bucket 6 is supported by the ground surface GS. Therefore, when the attachment AT takes the fourth position PS4, the dummy pin Pd is no longer subjected to the load due to the weight of the end attachment such as the bucket 6 or the load caused by the end attachment being pressed against the ground surface GS.

[0176] Specifically, when the attachment AT takes the fourth position PS4, for example, a gap is formed between the upper end of the dummy pin Pd and the upper end of the pinhole through which the dummy pin Pd is inserted, which is provided in an end attachment such as the bucket 6. Similarly, a gap is formed between the upper end of the dummy pin Pd and the upper end of the pinhole through which the dummy pin Pd is inserted, which is provided in the attachment AT, such as the tip of the arm 5. Furthermore, the lower end of the dummy pin Pd comes into contact with the lower ends of the pinholes in the end attachment and the attachment AT, resulting in a state in which only the weight of the dummy pin Pd is supported. Alternatively, the lower end of the dummy pin Pd comes into contact with the lower end of the pinhole in the end attachment, resulting in a gap being formed between the lower end of the dummy pin Pd and the lower end of the pinhole in the attachment AT.

[0177] In process P41, the target acquisition unit 305 of the controller 30 acquires, for example, the fourth attitude PS4 of the attachment AT stored in the auxiliary storage device 30A, and outputs it to the control signal generation unit 306 and the guidance generation unit 307. Thereafter, the controller 30 executes, for example, process P42 to make the attachment AT take the fourth attitude PS4, and process P43 to determine whether the current attitude of the attachment AT is the fourth attitude PS4.

[0178] For example, suppose that in the above-mentioned process P01, the operator of the excavator 100 selects manual control when selecting the attachment change mode. In this case, in process P42, the guidance generation unit 307 generates, for example, a control signal for displaying a guidance image GG showing the fourth position PS4 of the attachment AT, and outputs it to a display device included in the output device 50. The guidance generation unit 307 also generates, for example, a control signal for outputting audio guidance to guide the operator to take the fourth position PS4 of the attachment AT, and outputs it to a speaker included in the output device 50.

[0179] Also, in this process P42, the operator of the excavator 100 operates the operating device 26 while referring to the guidance image GG displayed on the display device of the output device 50 and listening to the audio guidance output from the speaker, to cause the attachment AT to take the fourth posture PS4 shown in Fig. 9. The posture calculation unit 303 of the controller 30 outputs, for example, the current posture of the attachment AT to the guidance generation unit 307.

[0180] Then, in process P43, the guidance generation unit 307, for example, compares the current posture of the attachment AT with the fourth posture PS4 and determines whether or not the current posture of the attachment AT satisfies the fourth posture PS4. In this process P43, if the guidance generation unit 307 determines, for example, that the current posture of the attachment AT does not satisfy the fourth posture PS4 (NO), it executes process P42 again and changes the guidance image GG and audio guidance according to the current posture of the attachment AT.

[0181] On the other hand, in process P33, if the guidance generating unit 307 determines that the current posture of the attachment AT satisfies the fourth posture PS4 (YES), it executes process P44, which prompts the removal of the dummy pin Pd. In this process P34, the guidance generating unit 307 outputs, for example, via the output device 50, a guidance image GG or audio guidance indicating that the attachment AT satisfies the fourth posture PS4 and that the dummy pin Pd can be removed.

[0182] When the attitude of the attachment AT satisfies the fourth attitude PS4, for example, as described above, a gap is generated between the upper end of the dummy pin Pd and the upper end of the pin hole of the end attachment and the upper end of the pin hole of the attachment AT. Also, when the attitude of the attachment AT satisfies the fourth attitude PS4, for example, as described above, the dummy pin Pd is supported by the lower ends of the pin holes of the end attachment and the attachment AT, or by only the lower end of the pin hole of the end attachment.

[0183] As a result, when the attitude of the attachment AT takes on the fourth attitude PS4, the radial force due to the end attachment's own weight and the radial force due to the end attachment being pressed against the ground surface GS no longer act on the dummy pin Pd. In other words, when the attitude of the attachment AT takes on the fourth attitude PS4, no radial force other than the force due to its own weight acts on the dummy pin Pd, and gaps are created between the upper ends of the dummy pins Pd and the upper ends of the pinholes of the end attachment and attachment AT.

[0184] As a result, when the posture of the attachment AT satisfies the fourth posture PS4, for example, the dummy pin Pd moves in the pin holes of the end attachment and the attachment AT, generating a metallic sound. Therefore, the operator of the excavator 100 or nearby workers can recognize that the posture of the attachment AT has satisfied the fourth posture PS4, for example, based on the metallic sound generated by the dummy pin Pd moving in the pin holes of the end attachment and the attachment AT.

[0185] Thereafter, the operator of the excavator 100 or a nearby worker follows, for example, the guidance image GG or the audio guidance to remove the dummy pin Pd from the attachment AT that has taken the fourth posture PS4.

[0186] In process P44, for example, when the operator of the shovel 100 inputs via the input device 52 that removal of the dummy pin Pd has been completed, the controller 30 ends the process flow shown in Fig. 8, for example, and ends the attachment replacement mode. Thereafter, the operator of the shovel 100 operates the operation device 26, for example, to cause the attachment AT to assume the fourth standby position PS4P as shown in Fig. 9, thereby separating the bucket 6 from the link mechanism L, and performs the task of replacing the bucket 6 with another end attachment.

[0187] As described above, in the end attachment replacement mode of the shovel 100 of this embodiment, the controller 30 acquires the third posture PS3. The third posture PS3 is a posture in which, with the first pin P1 of the attachment AT replaced with a dummy pin Pd having a smaller diameter, the center of gravity GC of the attachment AT is located directly below the dummy pin Pd and the second link L2 of the link mechanism L is aligned in the vertical direction.

[0188] With this configuration, most of the load due to the weight of the end attachment, such as the bucket 6, acts on the dummy pin Pd, and the load due to the weight of the end attachment acting on the second pin P2 can be reduced to as close to zero as possible. This makes it easy for an operator or worker to remove the second pin P2, and makes it easy to replace the end attachment.

[0189] In the excavator 100 of this embodiment, the controller 30 acquires a fourth posture PS4 in the end attachment replacement mode. The fourth posture PS4 is a posture in which, with the second pin P2 removed from the attachment AT and an end attachment such as the bucket 6 on the ground, a gap is generated between the upper end of the dummy pin Pd and the upper end of the pin hole of the end attachment.

[0190] With this configuration, the dummy pins Pd are not subjected to the load caused by the weight of the end attachment such as the bucket 6 or the load caused by the end attachment being pressed against the ground surface GS. Therefore, the operator or worker can easily remove the dummy pins Pd, and the end attachment such as the bucket 6 can be easily replaced.

[0191] The end attachment replacement method of this embodiment also includes a step P32 of causing the attachment AT to assume a third position PS3. The third position PS3 is a position in which, with the first pin P1 of the attachment AT replaced with a smaller-diameter dummy pin Pd, the center of gravity GC of the end attachment, such as the bucket 6, is located directly below the dummy pin Pd and the second link L2 of the link mechanism L is parallel to the vertical direction.

[0192] With this configuration, most of the load due to the weight of the end attachment, such as the bucket 6, acts on the dummy pin Pd, and the load due to the weight of the end attachment acting on the second pin P2 can be reduced to as close to zero as possible. This makes it easy for an operator or worker to remove the second pin P2, and makes it easy to replace the end attachment.

[0193] The end attachment replacement method of this embodiment also includes a step P42 of causing the attachment AT to assume a fourth position PS4. The fourth position PS4 of the attachment AT is a position in which, with the second pin P2 removed from the attachment AT and an end attachment such as a bucket 6 in contact with the ground, a gap is created between the upper end of the dummy pin Pd and the upper end of the pin hole in the end attachment.

[0194] With this configuration, the dummy pin Pd is not subjected to the load caused by the weight of the end attachment such as the bucket 6 or the load caused by the bucket 6 being pressed against the ground surface GS. Therefore, the operator or worker can easily remove the dummy pin Pd, and the end attachment such as the bucket 6 can be easily replaced.

[0195] In the end attachment replacement method of this embodiment, the first position PS1 is a position in which there is a gap between the end attachment such as the bucket 6 and the ground surface GS.

[0196] With this configuration, when the attachment AT assumes the first posture PS1, no reaction force from the ground surface GS acts on the end attachment, and only the load due to the end attachment's own weight acts on the first pin P1 and the second pin P2. Furthermore, since the second pin P2 bears almost all of the load due to the end attachment's own weight, the load acting on the first pin P1 due to the end attachment's own weight is minimized and approaches zero as much as possible. Similarly, since the first pin P1 bears almost all of the load due to the end attachment's own weight, the load acting on the second pin P2 due to the end attachment's own weight is minimized and approaches zero as much as possible. Therefore, simply by adjusting the position of the second pin P2 or the first pin P1 and the position of the center of gravity GC of the end attachment, the load acting on the first pin P1 or the second pin P2 due to the end attachment's own weight can be minimized. Therefore, according to the end attachment replacement method of this embodiment, it is possible for the worker to easily remove the first pin P1 or the second pin P2.

[0197] As described above, according to this embodiment, similar to the first embodiment described above, it is possible to provide a shovel 100 that allows easy replacement of an end attachment, and a method for replacing an end attachment. Note that the shovel and method for replacing an end attachment according to the present disclosure are not limited to the embodiment described above. Below, a modified example of the embodiment described above will be described with reference to FIG. 10.

[0198] Fig. 10 is a block diagram showing the configuration of an operation support system SYS for the shovel 100. As shown in Fig. 10, the operation support system SYS includes the shovel 100 and a remote control room RC. Note that the detailed configuration of the shovel 100 is omitted from Fig. 10 because the shovel 100 shown in Fig. 10 has the same configuration as the shovel 100 shown in Fig. 1.

[0199] The shovel 100 and the remote control room RC are connected to each other so as to be able to send and receive data via a communication line NW. Note that the shovel 100 and the remote control room RC may also be connected to each other so as to be able to send and receive data directly to each other without going through the communication line NW. In the illustrated example, the shovel 100 transmits information about the work site to the remote control room RC. This allows the remote operator RO in the remote control room RC to understand the situation at the work site based on the information from the shovel 100.

[0200] The shovel 100 is provided with a sensor that can three-dimensionally recognize the position and shape of an object present at the work site. For example, the shovel 100 is provided with a spatial recognition device. Therefore, the shovel 100 can transmit the results of three-dimensionally measuring the work site to the remote control room RC.

[0201] The spatial recognition device is a device for recognizing the space around the shovel 100. In the illustrated example, the spatial recognition device is a LiDAR. The LiDAR measures the distance between the LiDAR and each of one million or more points within a monitoring range. The spatial recognition device may be any device that can measure the distance to an object. For example, the spatial recognition device may be a stereo camera, or may be a combination of the imaging device 40 and a ranging device such as a millimeter-wave radar.

[0202] The operation support system SYS may include one or more shovels 100. When the system includes multiple shovels 100, the remote operator RO operating a specific shovel 100 can obtain information about the work site obtained by the specific shovel 100, as well as information about the work site obtained by one or more other shovels 100.

[0203] The remote control room RC is equipped with a remote communication device 60E, a remote controller 30E, a remote operation device 26E, an operation sensor 29E, and a remote output device 50E including a display device. The remote control room RC is also equipped with an operation seat DS where a remote operator RO who remotely operates the excavator 100 sits.

[0204] The remote communication device 60E is configured to be able to communicate with the communication device 60 attached to the excavator 100.

[0205] The remote controller 30E is a computing device that executes various calculations. In this embodiment, the remote controller 30E is configured as a microcomputer including a CPU and memory. The various functions of the remote controller 30E are realized by the CPU executing programs stored in the memory.

[0206] The display device included in the remote output device 50E is a device capable of displaying various types of information. The display device displays an image based on information transmitted from the shovel 100 so that the remote operator RO in the remote control room RC can visually recognize the surroundings of the shovel 100. In the illustrated example, the display device is a liquid crystal display that displays an image captured by the imaging device 40 mounted on the shovel 100. The display device may be a display or projector that realizes naked-eye stereoscopic vision, or may be VR goggles or the like.

[0207] The remote control device 26E is provided with an operation sensor 29E for detecting the operation content of the remote control device 26E. The operation sensor 29E is, for example, an inclination sensor that detects the inclination angle of the operation lever, or an angle sensor that detects the swing angle of the operation lever around the swing axis. The operation sensor 29E may be composed of other sensors such as a pressure sensor, a current sensor, a voltage sensor, or a distance sensor. The operation sensor 29E outputs information regarding the detected operation content of the remote control device 26E to the remote controller 30E. The remote controller 30E generates an operation signal based on the received information and transmits the generated operation signal to the shovel 100. The operation sensor 29E may be configured to generate the operation signal. In this case, the operation sensor 29E may output the operation signal to the remote communication device 60E without passing through the remote controller 30E. With this configuration, the remote operator RO can remotely operate the shovel 100 from the remote control room RC.

[0208] As described above, the operation support system SYS of this embodiment includes the shovel 100, the remote operation device 26E, and the remote communication device 60E. The shovel 100 includes a communication device 60 that can communicate with the remote communication device 60E. With this configuration, the operation support system SYS of this embodiment can make it easy for a worker at the work site to replace the end attachment of the shovel 100 when the remote operator RO remotely operates the shovel 100.

[0209] The preferred embodiments of the present disclosure have been described above. However, the invention according to the present disclosure is not limited to the above-described embodiments. Various modifications, substitutions, etc. may be applied to the above-described embodiments without departing from the scope of the invention according to the present disclosure. Furthermore, each of the features described with reference to the above-described embodiments may be combined as appropriate as long as there is no technical contradiction. [Explanation of symbols]

[0210] 1 Undercarriage 3 Upper rotating body 6 Bucket (end attachment) 6G Grapple (end attachment) 30 Controllers 100 Shovel AT Attachment BM support member GC center of gravity L-link mechanism L2 Second Link (Link) P1 First pin P2 Second pin P12 Process of making the attachment take the first position P22 The process of making the attachment take the second posture P32 Process of making the attachment take the third position P42 The process of making the attachment take the fourth position Pd dummy pin PS1 1st posture PS2 2nd posture PS3 3rd posture PS4 4th posture

Claims

1. a lower running body; an upper rotating body rotatably provided on the lower traveling body; an attachment provided on the upper rotating body; a controller that acquires the posture of the attachment; The attachment has an end attachment rotatably provided via a first pin, and a link mechanism attached to the end attachment via a second pin to rotate the end attachment, the controller has an end attachment exchange mode that acquires a first posture of the attachment in which a load acting on the first pin or the second pin due to the weight of the end attachment is equal to or less than a threshold. Shovel.

2. In the end attachment exchange mode, the controller determines whether a load acting on the second pin due to the weight of the end attachment is maximized and whether a link of the link mechanism attached to the end attachment via the second pin assumes the first posture along a vertical direction; The shovel according to claim 1.

3. In the end attachment exchange mode, the controller acquires a second posture of the attachment in which the weight of the end attachment is supported by the support member in a state in which the first pin is removed from the attachment and a support member is disposed below the center of gravity of the end attachment; The shovel according to claim 2.

4. In the end attachment exchange mode, the controller acquires a third posture of the attachment in which, with the first pin of the attachment replaced with a dummy pin having a smaller diameter, the center of gravity of the end attachment is located directly below the dummy pin and the link is aligned in a vertical direction. The shovel according to claim 2.

5. In the end attachment exchange mode, the controller, with the second pin removed from the attachment and the end attachment in a grounded state, acquires a fourth posture of the attachment that generates a gap between an upper end of the dummy pin and upper ends of pin holes of the attachment and the end attachment; The shovel according to claim 4.

6. the first attitude is an attitude in which there is a gap between the end attachment and the ground surface; The shovel according to claim 1.

7. A method for replacing an end attachment of a shovel, comprising: The shovel includes a lower traveling body, an upper rotating body rotatably provided on the lower traveling body, and an attachment provided on the upper rotating body, The attachment has the end attachment rotatably provided via a first pin, and a link mechanism attached to the end attachment via a second pin to rotate the end attachment, a step of causing the end attachment to take a first posture in which a load acting on the first pin or the second pin due to the weight of the end attachment is equal to or less than a threshold value; How to replace the end attachment.

8. a step of causing the attachment to take the first posture in which a load acting on the second pin due to the weight of the end attachment becomes maximum and a link of the link mechanism attached to the end attachment via the second pin becomes parallel to the vertical direction, The method for replacing an end attachment according to claim 7.

9. and a step of removing the first pin from the attachment and causing the attachment to assume a second posture in which the weight of the end attachment is supported by the support member while a support member is disposed below the center of gravity of the end attachment. The method for replacing an end attachment according to claim 8.

10. and a step of causing the attachment to assume a third posture in which, with the first pin of the attachment replaced with a dummy pin having a smaller diameter, the center of gravity of the end attachment is located directly below the dummy pin and the link is parallel to the vertical direction. The method for replacing an end attachment according to claim 8.

11. and a step of removing the second pin from the attachment and causing the attachment to assume a fourth posture in which a gap is generated between an upper end of the dummy pin and an upper end of the pin hole of the end attachment in a state in which the second pin is removed from the attachment and the end attachment is grounded. The method for replacing an end attachment according to claim 10.

12. the first attitude is an attitude in which there is a gap between the end attachment and the ground surface; The method for replacing an end attachment according to claim 7.

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