Shovel

Abstract

To improve accuracy of facing control for making an upper rotating body directly face a target construction surface.SOLUTION: A shovel comprises: a lower running body; an upper rotating body rotatably mounted on the lower running body; and a control device that performs facing control in which the upper rotating body is made to directly face a target construction surface by applying a rotational force to the lower running body or the upper rotating body to rotate. The control device controls a rotation speed of the lower running body or the upper rotating body based on a rotation angle required for the upper rotating body to directly face the target construction surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an excavator.

Background Art

[0002] Conventionally, in an excavator, so-called alignment control for aligning the upper slewing body with the target construction surface is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In work using an excavator, by improving the accuracy of alignment, the work can be performed accurately and the work efficiency can be improved.

[0005] Therefore, it is preferable to provide an excavator capable of improving the accuracy of alignment control for aligning the upper slewing body with the target construction surface.

Means for Solving the Problems

[0006] To achieve the above object, the present disclosure includes a lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, and a control device that performs alignment control to align the upper slewing body with the target construction surface by applying a turning force to the lower traveling body or the upper slewing body to turn it. The control device is an excavator that controls the turning speed of the lower traveling body or the upper slewing body based on the turning angle required until the upper slewing body faces the target construction surface.

[0007] Further, a lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, and a control device that performs alignment control to align the upper slewing body with a target construction surface by applying a turning force to the lower traveling body or the upper slewing body to cause turning. The control device is an excavator that gives a notification when the upper slewing body is likely to exceed the alignment position with the target construction surface as the lower traveling body or the upper slewing body turns.

Advantages of the Invention

[0008] According to the present disclosure, the accuracy of the alignment control for aligning the upper slewing body with the target construction surface can be improved.

Brief Description of the Drawings

[0009]

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MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] FIG. 1 is a side view of an excavator 100 as a digging machine according to an embodiment of the present invention.

[0012] An upper slewing body 3 is rotatably mounted on a lower traveling body 1 of the excavator 100 via a slewing mechanism 2. A boom 4 is attached to the upper slewing body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 as an end attachment is attached to the tip of the arm 5.

[0013] The boom 4, the arm 5, and the bucket 6 constitute a digging attachment as an example of an attachment. The boom 4 is driven by a boom cylinder 7, the arm 5 is driven by an arm cylinder 8, and the bucket 6 is driven by a bucket cylinder 9. A boom angle sensor S1 is attached to the boom 4, an arm angle sensor S2 is attached to the arm 5, and a bucket angle sensor S3 is attached to the bucket 6.

[0014] The boom angle sensor S1 is configured to detect the rotation angle of the boom 4. In this embodiment, the boom angle sensor S1 is an acceleration sensor and can detect the rotation angle of the boom 4 with respect to the upper slewing body 3 (hereinafter referred to as the "boom angle"). The boom angle, for example, becomes the minimum angle when the boom 4 is lowered to the lowest position, and increases as the boom 4 is raised.

[0015] The arm angle sensor S2 is configured to detect the rotation angle of the arm 5. In this embodiment, the arm angle sensor S2 is an acceleration sensor and can detect the rotation angle of the arm 5 with respect to the boom 4 (hereinafter referred to as the "arm angle"). The arm angle, for example, becomes the minimum angle when the arm 5 is closed to the maximum extent, and increases as the arm 5 is opened.

[0016] The bucket angle sensor S3 is configured to detect the rotation angle of the bucket 6. In this embodiment, the bucket angle sensor S3 is an acceleration sensor and can detect the rotation angle of the bucket 6 with respect to the arm 5 (hereinafter referred to as the "bucket angle"). The bucket angle, for example, becomes the minimum angle when the bucket 6 is closed to the maximum extent, and increases as the bucket 6 is opened.

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

[0018] The upper slewing body 3 is provided with a cabin 10 which is a driver's cab, and a power source such as an engine 11 is mounted thereon. Further, a controller 30, a display device 40, an input device 42, an audio output device 43, a storage device 47, a body tilt sensor S4, a slewing angular velocity sensor S5, a camera S6, a communication device T1, a positioning device P1, etc. are attached to the upper slewing body 3.

[0019] The controller 30 is configured to function as a main control unit that performs drive control of the excavator 100. In the present embodiment, the controller 30 is composed of a computer including a CPU, a RAM, a ROM, etc. Various functions of the controller 30 are realized, for example, by the CPU executing a program stored in the ROM. The various functions include, for example, a machine guidance function that guides (guides) the manual operation of the excavator 100 by the operator, and a machine control function that automatically supports the manual operation of the excavator 100 by the operator. The machine guidance device 50 included in the controller 30 is configured to execute the machine guidance function and the machine control function.

[0020] The display device 40 is configured to display various information. The display device 40 may be connected to the controller 30 via a communication network such as CAN, or may be connected to the controller 30 via a dedicated line. Further, the display device 40 can notify, by an alarm using characters or images or the like, when the upper swing body 3 is likely to exceed the correct alignment position with the target construction surface or when the upper swing body 3 has exceeded the correct alignment position with the target construction surface in the later-described correct alignment control under the control of the controller 30.

[0021] The input device 42 is configured such that the operator can input various information to the controller 30. The input device 42 includes a touch panel, a knob switch, a membrane switch, etc. installed in the cab 10.

[0022] The sound output device 43 is configured to output information by sound. The sound output device 43 may be, for example, an in-vehicle speaker connected to the controller 30, or may be an alarm such as a buzzer. In the present embodiment, the sound output device 43 is configured to output various information by voice in response to a voice output command from the controller 30. Further, the sound output device 43 can notify, by an alarm or the like, when the upper swing body 3 is likely to exceed the correct alignment position with the target construction surface or when the upper swing body 3 has exceeded the correct alignment position with the target construction surface in the later-described correct alignment control under the control of the controller 30.

[0023] The storage device 47 is configured to store various types of information. The storage device 47 is, for example, a non-volatile storage medium such as a semiconductor memory. The storage device 47 may store information output by various devices during the operation of the excavator 100, or may store information acquired via various devices before the operation of the excavator 100 is started. The storage device 47 may store, for example, information regarding a target construction surface acquired via a communication device T1 or the like. The target construction surface may be set by an operator of the excavator 100, or may be set by a construction manager or the like.

[0024] The body tilt sensor S4 is configured to detect the tilt of the upper swing body 3 with respect to the virtual horizontal plane. In the present embodiment, the body tilt sensor S4 is an acceleration sensor that detects the tilt angle around the front-rear axis and the tilt angle around the left-right axis of the upper swing body 3. The front-rear axis and the left-right axis of the upper swing body 3 are orthogonal to each other at, for example, the excavator center point, which is a point on the swing axis of the excavator 100.

[0025] The swing angular velocity sensor S5 is configured to detect the swing angular velocity of the upper swing body 3. The swing angular velocity sensor S5 may be configured to detect or calculate the swing angle of the upper swing body 3. In the present embodiment, the swing angular velocity sensor S5 is a gyro sensor. The swing angular velocity sensor S5 may be a resolver, a rotary encoder, or the like.

[0026] The camera S6 is an example of a space recognition device and is configured to acquire an image of the periphery of the excavator 100. In the present embodiment, the camera S6 includes a front camera S6F that images the space in front of the excavator 100, a left camera S6L that images the space to the left of the excavator 100, a right camera S6R that images the space to the right of the excavator 100, and a rear camera S6B that images the space behind the excavator 100.

[0027] The camera S6 is, for example, a monocular camera having an imaging device such as a CCD or a CMOS, and outputs the captured image to the display device 40. The camera S6 may be a stereo camera, a distance image camera, or the like. Further, the camera S6 may be replaced with another spatial recognition device such as an ultrasonic sensor, a millimeter wave radar, a LIDAR, or an infrared sensor, or may be replaced with a combination of another spatial recognition device and a camera.

[0028] The front camera S6F is attached, for example, to the ceiling of the cabin 10, that is, inside the cabin 10. However, the front camera S6F may be attached to the roof of the cabin 10, that is, outside the cabin 10. The left camera S6L is attached to the left end of the upper surface of the upper swing body 3, the right camera S6R is attached to the right end of the upper surface of the upper swing body 3, and the rear camera S6B is attached to the rear end of the upper surface of the upper swing body 3.

[0029] The communication device T1 controls communication with an external device outside the excavator 100. In the present embodiment, the communication device T1 controls communication with an external device via a satellite communication network, a mobile phone communication network, the Internet, or the like. The external device may be, for example, a management device such as a server installed in an external facility, or an assistance device such as a smartphone carried by an operator around the excavator 100. The external device is configured to be able to manage construction information regarding, for example, one or more excavators 100. The construction information includes information regarding at least one of, for example, the operating time, fuel consumption, and work amount of the excavator 100. The work amount is, for example, the amount of earth and sand excavated and the amount of earth and sand loaded on the dump truck bed. The excavator 100 is configured to transmit construction information regarding the excavator 100 to the external device at a predetermined time interval via the communication device T1.

[0030] The positioning device P1 is configured to measure the position of the upper swing body 3. The positioning device P1 may be configured to measure the orientation of the upper swing body 3. In the present embodiment, the positioning device P1 is, for example, a GNSS compass, which detects the position and orientation of the upper swing body 3 and outputs the detected values to the controller 30. Therefore, the positioning device P1 can function as an orientation detection device that detects the orientation of the upper swing body 3. The orientation detection device may be an azimuth sensor attached to the upper swing body 3.

[0031] FIG. 2 is a block diagram showing a configuration example of the drive system of the excavator 100, in which the mechanical power system, the hydraulic oil line, the pilot line, and the electric control system are indicated by double lines, solid lines, broken lines, and dotted lines, respectively.

[0032] The drive system of the excavator 100 mainly includes an engine 11, a regulator 13, a main pump 14, a pilot pump 15, a control valve 17, an operating device 26, a discharge pressure sensor 28, an operating pressure sensor 29, a controller 30, a proportional valve 31, and the like.

[0033] The engine 11 is a drive source of the excavator 100. In the present embodiment, the engine 11 is, for example, a diesel engine that operates to maintain a predetermined rotational speed. The output shaft of the engine 11 is connected to the input shafts of the main pump 14 and the pilot pump 15, respectively.

[0034] The main pump 14 is configured to supply hydraulic oil to the control valve 17 via the hydraulic oil line. In the present embodiment, the main pump 14 is a swash plate type variable displacement hydraulic pump.

[0035] The regulator 13 is configured to control the discharge rate of the main pump 14. In the present embodiment, the regulator 13 controls the discharge rate of the main pump 14 by adjusting the swash plate tilt angle of the main pump 14 in response to a control command from the controller 30. For example, the controller 30 receives the output of the operation pressure sensor 29 or the like, and outputs a control command to the regulator 13 as necessary to change the discharge rate of the main pump 14.

[0036] The pilot pump 15 supplies hydraulic oil to various hydraulic control devices including the operation device 26 and the proportional valve 31 via a pilot line. In the present embodiment, the pilot pump 15 is a fixed displacement hydraulic pump. However, the pilot pump 15 may be omitted. In this case, the function performed by the pilot pump 15 may be realized by the main pump 14. That is, the main pump 14 may be provided with a circuit separate from the function of supplying hydraulic oil to the control valve 17, and may have a function of supplying hydraulic oil to the operation device 26 or the like after reducing the supply pressure of the hydraulic oil by means of a throttle or the like.

[0037] The control valve 17 is a hydraulic control device that controls the hydraulic system in the excavator 100. In the present embodiment, the control valve 17 includes control valves 171 to 176. The control valve 17 can selectively supply the hydraulic oil discharged by the main pump 14 to one or a plurality of hydraulic actuators through the control valves 171 to 176. The control valves 171 to 176 are configured to control the flow rate of the hydraulic oil flowing from the main pump 14 to the hydraulic actuator and the flow rate of the hydraulic oil flowing from the hydraulic actuator to the hydraulic oil tank. The hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left travel hydraulic motor 1L, a right travel hydraulic motor 1R, and a swing hydraulic motor 2A. The swing hydraulic motor 2A may be a swing motor generator as an electric actuator.

[0038] The operating device 26 is a device used by an operator for operating the actuator. The actuator includes at least one of a hydraulic actuator and an electric actuator. In the present embodiment, the operating device 26 supplies the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via a pilot line. The pressure of the hydraulic oil (pilot pressure) supplied to each of the pilot ports is, in principle, a pressure corresponding to the operating direction and operating amount of the operating device 26 corresponding to each of the hydraulic actuators. At least one of the operating devices 26 is configured to be able to supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via a pilot line and a shuttle valve 32.

[0039] The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In the present embodiment, the discharge pressure sensor 28 outputs the detected value to the controller 30.

[0040] The operating pressure sensor 29 is configured to detect the operation content of the operator using the operating device 26. In the present embodiment, the operating pressure sensor 29 detects the operating direction and operating amount of the operating device 26 corresponding to each of the actuators in the form of pressure, and outputs the detected value to the controller 30. The operation content of the operating device 26 may be detected using other sensors other than the operating pressure sensor.

[0041] The proportional valve 31 that functions as a control valve for machine control is disposed in the pipeline connecting the pilot pump 15 and the shuttle valve 32, and is configured to be able to change the flow passage area of the pipeline. In the present embodiment, the proportional valve 31 operates according to a control command output by the controller 30. Therefore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via the proportional valve 31 and the shuttle valve 32, regardless of the operation of the operating device 26 by the operator.

[0042] The shuttle valve 32 has two inlet ports and one outlet port. One of the two inlet ports is connected to the operating device 26, and the other is connected to the proportional valve 31. The outlet port is connected to the pilot port of the corresponding control valve in the control valve 17. Therefore, the shuttle valve 32 can apply the higher one of the pilot pressure generated by the operating device 26 and the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve.

[0043] With this configuration, the controller 30 can operate the hydraulic actuator corresponding to the specific operating device 26 even when an operation on the specific operating device 26 is not being performed.

[0044] Next, the machine guidance device 50 included in the controller 30 will be described.

[0045] The machine guidance device 50 is configured to execute, for example, a machine guidance function. In the present embodiment, the machine guidance device 50 conveys work information such as the distance between the target construction surface and the working part of the attachment to the operator. Information regarding the target construction surface is, for example, stored in advance in the storage device 47. The machine guidance device 50 may acquire information regarding the target construction surface from an external device via the communication device T1. Information regarding the target construction surface is, for example, expressed in a reference coordinate system. The reference coordinate system is, for example, the World Geodetic System. The World Geodetic System is a three-dimensional orthogonal XYZ coordinate system with the origin at the center of gravity of the Earth, the X-axis in the direction of the intersection of the Greenwich meridian and the equator, the Y-axis in the direction of 90 degrees east longitude, and the Z-axis in the direction of the North Pole. The target construction surface may be set based on the relative positional relationship with a reference point. In this case, the operator may define an arbitrary point at the construction site as the reference point. The working part of the attachment is, for example, the tip of the bucket 6 or the back surface of the bucket 6. The machine guidance device 50 may be configured to guide the operation of the excavator 100 by conveying work information to the operator via the display device 40 or the sound output device 43 or the like. Further, the machine guidance device 50 gives a notification when the upper swing body 3 is likely to exceed the facing position with the target construction surface or when the upper swing body 3 has exceeded the facing position with the target construction surface in the facing control. The reference on the excavator 100 side for determining whether or not the upper swing body 3 is facing the target construction surface is, for example, the tip of the bucket 6 or the back surface of the bucket 6. The machine guidance device 50 may be configured to give a notification via the display device 40 or the sound output device 43 or the like when the upper swing body 3 is likely to exceed the facing position with the target construction surface or when the upper swing body 3 has exceeded the facing position with the target construction surface in the facing control.

[0046] The machine guidance device 50 may execute a machine control function for automatically assisting the manual operation of the excavator 100 by the operator. For example, when the operator is manually performing an excavation operation, the machine guidance device 50 may automatically operate at least one of the boom 4, the arm 5, and the bucket 6 so that the target construction surface and the tip position of the bucket 6 coincide.

[0047] In this embodiment, the machine guidance device 50 is incorporated in the controller 30, but it may be a control device provided separately from the controller 30. In this case, the machine guidance device 50 is composed of a computer including a CPU and an internal memory, for example, similar to the controller 30. Then, various functions of the machine guidance device 50 are realized by the CPU executing a program stored in the internal memory. Further, the machine guidance device 50 and the controller 30 are communicably connected to each other through a communication network such as CAN.

[0048] Specifically, the machine guidance device 50 acquires information from a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body inclination sensor S4, a turning angular velocity sensor S5, a camera S6, a positioning device P1, a communication device T1, an input device 42, and the like. Then, the machine guidance device 50 calculates, for example, the distance between the bucket 6 and the target construction surface based on the acquired information, and transmits the magnitude of the distance between the bucket 6 and the target construction surface to the operator of the excavator 100 by at least one of voice and image display. Further, the machine guidance device 50 limits the turning speed of the upper swing body 3 when the turning speed of the upper swing body 3 exceeds a predetermined speed when starting the facing control described later. Further, the machine guidance device 50 determines whether the upper swing body 3 is likely to exceed the facing position with the target construction surface or whether the upper swing body 3 has exceeded the facing position with the target construction surface based on the calculated distance, and notifies the operator of the fact when the upper swing body 3 is likely to exceed the facing position with the target construction surface or when the upper swing body 3 has exceeded the facing position with the target construction surface by at least one of sound and display.

[0049] Therefore, the machine guidance device 50 includes a position calculation unit 51, a distance calculation unit 52, an information transmission unit 53, an automatic control unit 54, and a turning speed calculation unit 57.

[0050] The position calculation unit 51 is configured to calculate the position of the object to be positioned. In the present embodiment, the position calculation unit 51 calculates the coordinate points in the reference coordinate system of the working part of the attachment. Specifically, the position calculation unit 51 calculates the coordinate points of the tip of the bucket 6 from the respective rotation angles of the boom 4, the arm 5, and the bucket 6. The position calculation unit 51 calculates not only the coordinate points at the center of the tip of the bucket 6, but also the coordinate points at the left end of the tip of the bucket 6 and the coordinate points at the right end of the tip of the bucket 6 in order to determine whether the upper swing body 3 is about to exceed the facing position with the target construction surface or whether the upper swing body 3 has exceeded the facing position with the target construction surface. Further, the position calculation unit 51 may calculate the swing angle of the upper swing body 3 based on the position of the bucket 6.

[0051] The distance calculation unit 52 is configured to calculate the distance between two objects to be positioned. In the present embodiment, the distance calculation unit 52 calculates the vertical distance between the tip of the bucket 6 and the target construction surface. The distance calculation unit 52 may calculate the distances (for example, vertical distances) between the respective coordinate points at the left end and the right end of the tip of the bucket 6 and the corresponding target construction surface so that the machine guidance device 50 can determine whether the excavator 100 is facing the target construction surface.

[0052] The swing speed calculation unit 57 calculates the swing speed of the upper swing body 3 based on the swing angle of the upper swing body 3 calculated by the position calculation unit 51. Specifically, the swing speed calculation unit 57 calculates the swing speed of the upper swing body 3 by differentiating the swing angle of the upper swing body 3 calculated by the position calculation unit 51 with respect to time.

[0053] The information transmission unit 53 is configured to transmit various types of information to the operator of the excavator 100. In the present embodiment, the information transmission unit 53 transmits the magnitudes of the various distances calculated by the distance calculation unit 52 to the operator of the excavator 100. Specifically, using at least one of visual information and auditory information, the magnitude of the vertical distance between the tip of the bucket 6 and the target construction surface is transmitted to the operator of the excavator 100. Further, the information transmission unit 53 notifies the operator of the excavator 100 when the upper swing body 3 is likely to exceed the facing position with the target construction surface or when the upper swing body 3 has exceeded the facing position with the target construction surface.

[0054] For example, the information transmission unit 53 may transmit the magnitude of the vertical distance between the tip of the bucket 6 and the target construction surface to the operator using intermittent sounds from the sound output device 43. In this case, the information transmission unit 53 may shorten the interval of the intermittent sounds as the vertical distance becomes smaller. The information transmission unit 53 may use continuous sounds, or may change at least one of the pitch and intensity of the sounds to represent the difference in the magnitude of the vertical distance. Further, the information transmission unit 53 may issue an alarm when the tip of the bucket 6 is at a position lower than the target construction surface. The alarm is, for example, a continuous sound significantly louder than the intermittent sound. Also, the information transmission unit 53 may notify the operator to that effect using the sound from the sound output device 43 when the upper swing body 3 is likely to exceed the facing position with the target construction surface or when the upper swing body 3 has exceeded the facing position with the target construction surface.

[0055] Further, the information transmission unit 53 may cause the display device 40 to display the magnitude of the vertical distance between the tip of the bucket 6 and the target construction surface as work information. The display device 40 displays, for example, the work information received from the information transmission unit 53 on the screen together with the image data received from the camera S6. The information transmission unit 53 may transmit the magnitude of the vertical distance to the operator using, for example, an image of an analog meter or an image of a bar graph indicator. Also, the information transmission unit 53 may notify the operator to that effect using characters or images via the display device 40 when the upper swing body 3 is likely to exceed the facing position with the target construction surface or when the upper swing body 3 has exceeded the facing position with the target construction surface.

[0056] The automatic control unit 54 automatically supports the manual operation of the excavator 100 by the operator by automatically operating the actuator. For example, when the operator is manually performing an arm closing operation, the automatic control unit 54 may automatically extend and contract at least one of the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 so that the target construction surface coincides with the position of the tip of the bucket 6. In this case, the operator can close the arm 5 while making the tip of the bucket 6 coincide with the target construction surface by, for example, only operating the arm operation lever in the closing direction. This automatic control may be configured to be executed when a predetermined switch, which is one of the input devices 42, is pressed. The predetermined switch may be, for example, a machine control switch (hereinafter referred to as "MC switch"), and may be arranged at the tip of the operating device 26 as a knob switch.

[0057] When a predetermined switch such as an MC switch is pressed, the automatic control unit 54 may automatically rotate the slewing hydraulic motor 2A to align the upper slewing body 3 with the target construction surface. In this case, the operator can align the upper slewing body 3 with the target construction surface by simply pressing a predetermined switch or by operating the slewing operation lever while pressing the predetermined switch. Alternatively, the operator can align the upper slewing body 3 with the target construction surface and start the machine control function by simply pressing a predetermined switch. At this time, based on the position of the bucket 6 calculated by the position calculation unit 51, the automatic control unit 54 may automatically rotate the slewing hydraulic motor 2A to align the upper slewing body 3 with the target construction surface on the condition that there is a construction surface directly below the bucket 6. Hereinafter, the control for aligning the upper slewing body 3 with the target construction surface is referred to as "alignment control". In the alignment control, the machine guidance device 50 determines that the excavator 100 is aligned with the target construction surface when the vertical distance from the coordinate point at the left end of the tip of the bucket 6 to the target construction surface (left-end vertical distance) is equal to the vertical distance from the coordinate point at the right end of the tip of the bucket 6 to the target construction surface (right-end vertical distance). However, even when the difference between the left-end vertical distance and the right-end vertical distance is not equal to zero, that is, when the difference between the left-end vertical distance and the right-end vertical distance is less than or equal to a predetermined value, the machine guidance device 50 may determine that the excavator 100 is aligned with the target construction surface. After automatically rotating the slewing hydraulic motor 2A, when the machine guidance device 50 determines that the excavator 100 is aligned with the target construction surface, it may use at least one of visual information and auditory information to notify the operator that the alignment control has been completed. That is, the machine guidance device 50 may notify the operator that the upper slewing body 3 has been aligned with the target construction surface.

[0058] In this embodiment, the automatic control unit 54 can automatically operate each actuator by individually and automatically adjusting the pilot pressure acting on the control valve corresponding to each actuator. For example, in the facing control, the automatic control unit 54 may operate the swing hydraulic motor 2A based on the difference between the left vertical distance and the right vertical distance. Specifically, when the swing operation lever is operated with a predetermined switch pressed, the automatic control unit 54 determines whether the swing operation lever is operated in a direction to face the upper swing body 3 toward the target construction surface. For example, when the swing operation lever is operated in a direction in which the vertical distance between the tip of the bucket 6 and the target construction surface (upward slope surface) increases, the automatic control unit 54 does not execute the facing control. On the other hand, when the swing operation lever is operated in a direction in which the vertical distance between the tip of the bucket 6 and the target construction surface (upward slope surface) decreases, the automatic control unit 54 executes the facing control. As a result, the automatic control unit 54 can operate the swing hydraulic motor 2A so that the difference between the left vertical distance and the right vertical distance becomes smaller. Thereafter, when the difference becomes less than or equal to a predetermined value or zero, the automatic control unit 54 stops the swing hydraulic motor 2A. Alternatively, the automatic control unit 54 may set the swing angle at which the difference becomes less than or equal to a predetermined value or zero as the target angle, and perform swing angle control so that the angle difference between the target angle and the current swing angle (detected value) becomes zero. In this case, the swing angle is, for example, the angle of the front-rear axis of the upper swing body 3 with respect to the reference direction.

[0059] Further, when an operation related to the target construction surface such as an excavation operation or a slope finishing operation is being performed, the automatic control unit 54 may automatically operate the actuator so that the state in which the upper swing body 3 faces the target construction surface is maintained. For example, when the orientation of the upper swing body 3 changes due to an excavation reaction force or the like and the upper swing body 3 no longer faces the target construction surface, the automatic control unit 54 may automatically operate the swing hydraulic motor 2A in order to quickly face the upper swing body 3 toward the target construction surface. Alternatively, when an operation related to the target construction surface is being performed, the automatic control unit 54 may prophylactically operate the actuator so that the orientation of the upper swing body 3 does not change due to an excavation reaction force or the like.

[0060] Further, when the turning speed of the upper slewing body 3 calculated by the turning speed calculation unit 57 exceeds a predetermined speed, the automatic control unit 54 restricts the turning speed of the turning hydraulic motor 2A in the facing control, thereby restricting the turning speed of the upper slewing body 3. The automatic control unit 54 obtains a predetermined speed that is a condition for restricting the rotational speed of the turning hydraulic motor 2A by using the turning angle of the upper slewing body 3 calculated by the position calculation unit 51 and the distance between the tip of the bucket 6 and the target construction surface calculated by the distance calculation unit 52. Specifically, the automatic control unit 54 calculates the turning angle required for the upper slewing body 3 to face the target construction surface by using the turning angle of the upper slewing body 3 calculated by the position calculation unit 51 and the distance between the tip of the bucket 6 and the target construction surface calculated by the distance calculation unit 52, and obtains a predetermined speed based on the calculated turning angle. For example, when the turning angle required for the upper slewing body 3 to face the target construction surface is large, since the angle turned at the restricted turning speed is large, even if the turning speed before restriction is large, the turning speed will sufficiently decrease before the upper slewing body 3 faces the target construction surface, and the possibility that the upper slewing body 3 exceeds the facing position with the target construction surface becomes low. Therefore, the predetermined speed that is a condition for restricting the rotational speed of the turning hydraulic motor 2A is set to be large. On the other hand, when the turning angle required for the upper slewing body 3 to face the target construction surface is small, since the angle turned at the restricted turning speed is small, if the turning speed before restriction is large, the turning speed will not sufficiently decrease before the upper slewing body 3 faces the target construction surface, and the possibility that the upper slewing body 3 exceeds the facing position with the target construction surface becomes high. Therefore, the predetermined speed that is a condition for restricting the rotational speed of the turning hydraulic motor 2A is set to be small. In this way, the automatic control unit 54 controls the turning speed of the upper slewing body 3 based on the turning angle required for the upper slewing body 3 to face the target construction surface. In addition to the above-described turning angle, the turning operation amount with respect to the operating device 26 may be used for setting the predetermined speed. Specifically, when the operation amount with respect to the operating device 26 is large, even if the turning speed is restricted at a predetermined speed based on the turning angle, the turning speed will exceed the predetermined speed as it reaches the predetermined speed while being accelerated, and the possibility that the upper slewing body 3 exceeds the facing position with the target construction surface becomes high.Therefore, when the operation amount for the operation device 26 is large, the predetermined speed may be set to be smaller than the predetermined speed obtained based on the turning angle. On the other hand, when the operation amount for the operation device 26 is small, if the turning speed is limited at the predetermined speed obtained based on the turning angle, the turning speed will sufficiently decrease before the upper swing body 3 faces the target construction surface, and the possibility that the upper swing body 3 exceeds the facing position with the target construction surface is low. Therefore, it is not necessary to reduce the predetermined speed obtained based on the turning angle according to the turning operation amount.

[0061] Next, referring to FIG. 3, a configuration example of the hydraulic system mounted on the excavator 100 will be described.

[0062] FIG. 3 is a schematic diagram showing a configuration example of the hydraulic system mounted on the excavator 100 of FIG. 1. Similar to FIG. 2, FIG. 3 shows the mechanical power system, the hydraulic oil line, the pilot line, and the electric control system with double lines, solid lines, broken lines, and dotted lines, respectively.

[0063] The hydraulic system circulates hydraulic oil from the main pumps 14L and 14R driven by the engine 11 to the hydraulic oil tank through at least one of the center bypass pipelines 40L and 40R and the parallel pipelines 42L and 42R. The main pumps 14L and 14R correspond to the main pump 14 in FIG. 2.

[0064] The center bypass pipeline 40L is a hydraulic oil line passing through the control valves 171, 173, 175L, and 176L arranged in the control valve 17. The center bypass pipeline 40R is a hydraulic oil line passing through the control valves 172, 174, 175R, and 176R arranged in the control valve 17. The control valves 175L and 175R correspond to the control valve 175 in FIG. 2. The control valves 176L and 176R correspond to the control valve 176 in FIG. 2.

[0065] The control valve 171 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged from the main pump 14L to the left travel hydraulic motor 1L and to discharge the hydraulic oil discharged from the left travel hydraulic motor 1L to the hydraulic oil tank.

[0066] The control valve 172 is a spool valve that switches the flow of the hydraulic oil to supply the hydraulic oil discharged from the main pump 14R to the right travel hydraulic motor 1R and to discharge the hydraulic oil discharged from the right travel hydraulic motor 1R to the hydraulic oil tank.

[0067] The control valve 173 is a spool valve that switches the flow of the hydraulic oil to supply the hydraulic oil discharged from the main pump 14L to the swing hydraulic motor 2A and to discharge the hydraulic oil discharged from the swing hydraulic motor 2A to the hydraulic oil tank.

[0068] The control valve 174 is a spool valve that switches the flow of the hydraulic oil to supply the hydraulic oil discharged from the main pump 14R to the bucket cylinder 9 and to discharge the hydraulic oil in the bucket cylinder 9 to the hydraulic oil tank.

[0069] The control valves 175L and 175R are spool valves that switch the flow of the hydraulic oil to supply the hydraulic oil discharged from the main pumps 14L and 14R to the boom cylinder 7 and to discharge the hydraulic oil in the boom cylinder 7 to the hydraulic oil tank.

[0070] The control valves 176L and 176R are spool valves that switch the flow of the hydraulic oil to supply the hydraulic oil discharged from the main pumps 14L and 14R to the arm cylinder 8 and to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0071] The parallel pipeline 42L is a hydraulic oil line parallel to the center bypass pipeline 40L. The parallel pipeline 42L is configured to supply hydraulic oil to a downstream control valve when the flow of hydraulic oil through the center bypass pipeline 40L is restricted or blocked by any of the control valves 171, 173, 175L. The parallel pipeline 42R is a hydraulic oil line parallel to the center bypass pipeline 40R. The parallel pipeline 42R is configured to supply hydraulic oil to a downstream control valve when the flow of hydraulic oil through the center bypass pipeline 40R is restricted or blocked by any of the control valves 172, 174, 175R.

[0072] The regulators 13L, 13R control the discharge amounts of the main pumps 14L, 14R by adjusting the swash plate tilt angles of the main pumps 14L, 14R according to the discharge pressures of the main pumps 14L, 14R. The regulators 13L, 13R correspond to the regulator 13 in FIG. 2. For example, the regulator 13L adjusts the swash plate tilt angle of the main pump 14L in response to an increase in the discharge pressure of the main pump 14L to decrease the discharge amount. The same applies to the regulator 13R. This is to ensure that the absorption power (absorption horsepower) of the main pump 14, which is represented by the product of the discharge pressure and the discharge amount, does not exceed the output power (output horsepower) of the engine 11.

[0073] The discharge pressure sensor 28L is an example of the discharge pressure sensor 28, detects the discharge pressure of the main pump 14L, and outputs the detected value to the controller 30. The same applies to the discharge pressure sensor 28R.

[0074] Here, the negative control used in the hydraulic system of FIG. 3 will be described.

[0075] In the center bypass pipeline 40L, a throttle 18L is arranged between the most downstream control valve 176L and the hydraulic oil tank. The flow of the hydraulic oil discharged by the main pump 14L is restricted by the throttle 18L. Then, the throttle 18L generates a control pressure for controlling the regulator 13L. The control pressure sensor 19L is a sensor for detecting the control pressure and outputs the detected value to the controller 30. Similarly, in the center bypass pipeline 40R, a throttle 18R is arranged between the most downstream control valve 176R and the hydraulic oil tank. The flow of the hydraulic oil discharged by the main pump 14R is restricted by the throttle 18R. Then, the throttle 18R generates a control pressure for controlling the regulator 13R. The control pressure sensor 19R is a sensor for detecting the control pressure and outputs the detected value to the controller 30.

[0076] The controller 30 controls the discharge amount of the main pump 14L by adjusting the swash plate tilt angle of the main pump 14L according to the control pressure detected by the control pressure sensor 19L. The controller 30 decreases the discharge amount of the main pump 14L as the control pressure increases, and increases the discharge amount of the main pump 14L as the control pressure decreases.

[0077] Specifically, as shown in FIG. 3, in the standby state where none of the hydraulic actuators in the excavator 100 are operated, the hydraulic oil discharged by the main pump 14L reaches the throttle 18L through the center bypass pipeline 40L. Then, the flow of the hydraulic oil discharged by the main pump 14L increases the control pressure generated upstream of the throttle 18L. As a result, the controller 30 decreases the discharge amount of the main pump 14L to the allowable minimum discharge amount and suppresses the pressure loss (pumping loss) when the discharged hydraulic oil passes through the center bypass pipeline 40L.

[0078] When any one of the hydraulic actuators is operated, the hydraulic oil discharged by the main pump 14L flows into the hydraulic actuator to be operated through the control valve corresponding to the hydraulic actuator to be operated. Then, the flow of the hydraulic oil discharged by the main pump 14L reduces or eliminates the amount reaching the throttle 18L, and decreases the control pressure generated upstream of the throttle 18L. As a result, the controller 30 increases the discharge amount of the main pump 14L, circulates sufficient hydraulic oil to the hydraulic actuator to be operated, and ensures the driving of the hydraulic actuator to be operated. Note that the above description regarding the main pump 14L is similarly applicable to the main pump 14R.

[0079] With the above configuration, in the standby state, the hydraulic system of FIG. 3 can suppress the wasteful energy consumption in the main pumps 14L and 14R. The wasteful energy consumption includes the pumping loss generated by the hydraulic oil discharged by the main pumps 14L and 14R in the center bypass pipelines 40L and 40R. Also, when operating the hydraulic actuator, the hydraulic system of FIG. 3 can supply sufficient hydraulic oil from the main pumps 14L and 14R to the hydraulic actuator to be operated.

[0080] Next, with reference to FIGS. 4A to 4C, a configuration for automatically operating the actuator will be described.

[0081] FIGS. 4A to 4C are diagrams showing a part of the hydraulic system extracted. Specifically, FIG. 4A is a diagram showing the part of the hydraulic system related to the operation of the boom cylinder 7, FIG. 4B is a diagram showing the part of the hydraulic system related to the operation of the bucket cylinder 9, and FIG. 4C is a diagram showing the part of the hydraulic system related to the operation of the swing hydraulic motor 2A.

[0082] The boom operation lever 26A in Fig. 4A is an example of the operation device 26 and is used to operate the boom 4. The boom operation lever 26A utilizes the hydraulic oil discharged by the pilot pump 15 and acts on the pilot ports of the control valves 175L and 175R with a pilot pressure according to the operation content. Specifically, when the boom operation lever 26A is operated in the boom raising direction, it acts on the right pilot port of the control valve 175L and the left pilot port of the control valve 175R with a pilot pressure according to the operation amount. Also, when the boom operation lever 26A is operated in the boom lowering direction, it acts on the right pilot port of the control valve 176R with a pilot pressure according to the operation amount.

[0083] The operation pressure sensor 29A is an example of the operation pressure sensor 29, detects the operation content of the operator on the boom operation lever 26A in the form of pressure, and outputs the detected value to the controller 30. The operation content is, for example, the operation direction and the operation amount (operation angle), etc.

[0084] The proportional valves 31AL and 31AR are examples of the proportional valve 31, and the shuttle valves 32AL and 32AR are examples of the shuttle valve 32. The proportional valve 31AL operates according to the current command output by the controller 30. Then, the proportional valve 31AL adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 through the proportional valve 31AL and the shuttle valve 32AL to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. The proportional valve 31AR operates according to the current command output by the controller 30. Then, the proportional valve 31AR adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 through the proportional valve 31AR and the shuttle valve 32AR to the right pilot port of the control valve 175R. The proportional valves 31AL and 31AR can adjust the pilot pressure so that the control valves 175L and 175R can be stopped at an arbitrary valve position.

[0085] With this configuration, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31AL and the shuttle valve 32AL, for example, regardless of the boom raising operation by the operator. That is, the controller 30 can automatically raise the boom 4. Also, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31AR and the shuttle valve 32AR, regardless of the boom lowering operation by the operator. That is, the controller 30 can automatically lower the boom 4.

[0086] The bucket operation lever 26B in Fig. 4B is an example of the operation device 26 and is used to operate the bucket 6. The bucket operation lever 26B utilizes the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the operation content to the pilot port of the control valve 174. Specifically, when the bucket operation lever 26B is operated in the bucket opening direction, it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 174. Also, when the bucket operation lever 26B is operated in the bucket closing direction, it applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 174.

[0087] The operation pressure sensor 29B is an example of the operation pressure sensor 29, detects the operation content of the operator on the bucket operation lever 26B in the form of pressure, and outputs the detected value to the controller 30.

[0088] The proportional valves 31BL and 31BR are examples of the proportional valve 31, and the shuttle valves 32BL and 32BR are examples of the shuttle valve 32. The proportional valve 31BL operates according to the current command output by the controller 30. Then, the proportional valve 31BL adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31BL and the shuttle valve 32BL. The proportional valve 31BR operates according to the current command output by the controller 30. Then, the proportional valve 31BR adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31BR and the shuttle valve 32BR. The proportional valves 31BL and 31BR can adjust the pilot pressure so that the control valve 174 can be stopped at an arbitrary valve position.

[0089] With this configuration, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31BL and the shuttle valve 32BL, regardless of the bucket closing operation by the operator. That is, the controller 30 can automatically close the bucket 6. Also, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31BR and the shuttle valve 32BR, regardless of the bucket opening operation by the operator. That is, the controller 30 can automatically open the bucket 6.

[0090] The swing operation lever 26C in Fig. 4C is an example of the operating device 26 and is used to swing the upper swing body 3. The swing operation lever 26C utilizes the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the operation content to the pilot port of the control valve 173. Specifically, when the swing operation lever 26C is operated in the left swing direction, a pilot pressure corresponding to the operation amount is applied to the left pilot port of the control valve 173. Also, when the swing operation lever 26C is operated in the right swing direction, a pilot pressure corresponding to the operation amount is applied to the right pilot port of the control valve 173.

[0091] The operation pressure sensor 29C is an example of the operation pressure sensor 29, detects the operation content of the operator on the turning operation lever 26C in the form of pressure, and outputs the detected value to the controller 30.

[0092] The proportional valves 31CL and 31CR are examples of the proportional valve 31, and the shuttle valves 32CL and 32CR are examples of the shuttle valve 32. The proportional valve 31CL operates according to the current command output by the controller 30. Then, the proportional valve 31CL adjusts the pilot pressure by the hydraulic oil introduced into the left pilot port of the control valve 173 from the pilot pump 15 via the proportional valve 31CL and the shuttle valve 32CL. The proportional valve 31CR operates according to the current command output by the controller 30. Then, the proportional valve 31CR adjusts the pilot pressure by the hydraulic oil introduced into the right pilot port of the control valve 173 from the pilot pump 15 via the proportional valve 31CR and the shuttle valve 32CR. The proportional valves 31CL and 31CR can adjust the pilot pressure so that the control valve 173 can be stopped at an arbitrary valve position.

[0093] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31CL and the shuttle valve 32CL regardless of the left turning operation by the operator. That is, the controller 30 can automatically turn the upper swing body 3 to the left. Also, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31CR and the shuttle valve 32CR regardless of the right turning operation by the operator. That is, the controller 30 can automatically turn the upper swing body 3 to the right.

[0094] The excavator 100 may be configured to automatically open and close the arm 5 and to automatically move the lower traveling body 1 forward and backward. In this case, the hydraulic system portion related to the operation of the arm cylinder 8, the hydraulic system portion related to the operation of the left traveling hydraulic motor 1L, and the hydraulic system portion related to the operation of the right traveling hydraulic motor 1R may be configured in the same manner as the hydraulic system portion related to the operation of the boom cylinder 7 and the like.

[0095] Next, with reference to FIG. 5, another configuration example of the machine guidance device 50 will be described.

[0096] FIG. 5 is a block diagram showing another configuration example of the drive system of the excavator 100 and corresponds to FIG. 2. The drive system of FIG. 5 is different from the drive system of FIG. 2 in that the machine guidance device 50 includes a turning angle calculation unit 55 and a relative angle calculation unit 56, but is common in other respects. Therefore, the description of the common parts will be omitted, and the different parts will be described in detail.

[0097] The turning angle calculation unit 55 calculates the turning angle of the upper slewing body 3. This is to specify the current orientation of the upper slewing body 3. In the present embodiment, the turning angle calculation unit 55 calculates, as the turning angle, the angle of the front-rear axis of the upper slewing body 3 with respect to the reference direction based on the output of the GNSS compass as the positioning device P1. The turning angle calculation unit 55 may calculate the turning angle based on the output of the turning angular velocity sensor S5. Further, when a reference point is set at the construction site, the turning angle calculation unit 55 may use the direction of the reference point viewed from the turning axis as the reference direction.

[0098] The turning angle indicates the direction in which the attachment operating surface extends. The attachment operating surface is, for example, a virtual plane that longitudinally cuts the attachment and is arranged to be perpendicular to the turning plane. The turning plane is, for example, a virtual plane including the bottom surface of the turning frame perpendicular to the turning axis. The machine guidance device 50 determines that the upper slewing body 3 is facing the target construction surface, for example, when it determines that the attachment operating surface AF (see FIG. 8A) includes the normal line of the target construction surface.

[0099] The relative angle calculation unit 56 calculates the relative angle as the turning angle necessary to align the upper slewing body 3 directly with the target construction surface. The relative angle is, for example, the relative angle formed between the direction of the front-rear axis of the upper slewing body 3 when the upper slewing body 3 is aligned directly with the target construction surface and the current direction of the front-rear axis of the upper slewing body 3. In the present embodiment, the relative angle calculation unit 56 calculates the relative angle based on the information regarding the target construction surface stored in the storage device 47 and the turning angle calculated by the turning angle calculation unit 55.

[0100] When the slewing operation lever is operated while a predetermined switch is pressed, the automatic control unit 54 determines whether or not the slewing operation lever has been operated in the direction of aligning the upper slewing body 3 directly with the target construction surface. When it is determined that the slewing operation lever has been operated in the direction of aligning the upper slewing body 3 directly with the target construction surface, the automatic control unit 54 sets the relative angle calculated by the relative angle calculation unit 56 as the target angle. Then, when the change in the turning angle after the slewing operation lever has been operated reaches the target angle, it is determined that the upper slewing body 3 is aligned directly with the target construction surface, and the movement of the slewing hydraulic motor 2A is stopped. Further, the automatic control unit 54 obtains a predetermined speed that is a condition for restricting the rotational speed of the slewing hydraulic motor 2A in the alignment control, using the turning angle of the upper slewing body 3 calculated by the turning angle calculation unit 55 and the relative angle calculated by the relative angle calculation unit 56.

[0101] In this way, the machine guidance device 50 in FIG. 5 can align the upper slewing body 3 directly with the target construction surface, similarly to the machine guidance device 50 in FIG. 2.

[0102] Next, with reference to FIGS. 6, 7A, 7B, 8A, and 8B, an example of the alignment control in which the controller 30 aligns the upper slewing body 3 directly with the target construction surface will be described.

[0103] FIG. 6 is a flowchart showing the process of facing control. The controller 30 executes this process when the MC switch is pressed. FIGS. 7A and 7B are top views of the excavator 100 when facing control is executed, and FIGS. 8A and 8B are perspective views of the excavator 100 when viewed from the left rear when facing control is executed. Specifically, FIGS. 7A and 8A show a state where the upper swing body 3 is not facing the target construction surface, and FIGS. 7B and 8B show a state where the upper swing body 3 is facing the target construction surface. The target construction surface in FIGS. 7A, 7B, 8A, and 8B is, for example, the uphill slope surface BS as shown in FIG. 1. And the area NS represents a state where the uphill slope surface BS is not completed, that is, a state where the ground surface ES does not coincide with the uphill slope surface BS as shown in FIG. 1, and the area CS represents a state where the uphill slope surface BS is completed, that is, a state where the ground surface ES coincides with the uphill slope surface BS.

[0104] The state where the upper swing body 3 is facing the target construction surface includes, for example, a state where, as shown in FIG. 7B, on the virtual horizontal plane, the angle α formed between the line segment L1 representing the direction (extension direction) of the target construction surface and the line segment L2 representing the longitudinal axis of the upper swing body 3 is 90 degrees. The extension direction of the slope surface as the direction of the target construction surface represented by the line segment L1 is, for example, a direction perpendicular to the slope length direction. The slope length direction is, for example, a direction along the virtual line segment connecting the upper end (slope shoulder) and the lower end (slope bottom) of the slope surface at the shortest distance. The state where the upper swing body 3 is facing the target construction surface may be defined as a state where, on the virtual horizontal plane, the angle β (see FIG. 7A) formed between the line segment L2 representing the longitudinal axis of the upper swing body 3 and the line segment L3 perpendicular to the direction (extension direction) of the target construction surface is 0 degrees. Note that the direction represented by the line segment L3 corresponds to the horizontal component direction of the perpendicular dropped to the target construction surface.

[0105] The virtual cylindrical body CB in FIGS. 8A and 8B represents a part of the normal line of the target construction surface (the upward slope surface BS), the dashed-dotted line represents a part of the virtual turning plane SF, and the dashed line represents a part of the virtual attachment operation surface AF. The attachment operation surface AF is arranged perpendicular to the turning plane SF. And as shown in FIG. 8B, when the upper slewing body 3 is facing the target construction surface, the attachment operation surface AF is arranged to include a part of the normal line represented by the virtual cylindrical body CB, that is, the attachment operation surface AF is arranged to extend along a part of the normal line.

[0106] The automatic control unit 54 sets, for example, the turning angle when the attachment operation surface AF and the target construction surface (the upward slope surface BS) are perpendicular as the target angle. Then, the automatic control unit 54 detects the current turning angle based on the output of the positioning device P1 or the like, and calculates the difference between the target angle and the current turning angle (the detected value). Then, the automatic control unit 54 operates the slewing hydraulic motor 2A so that the difference becomes less than or equal to a predetermined value or zero. Specifically, the automatic control unit 54 determines that the upper slewing body 3 is facing the target construction surface when the difference between the target angle and the current turning angle becomes less than or equal to a predetermined value or zero. In addition, when the slewing operation lever is operated with a predetermined switch pressed, the automatic control unit 54 determines whether the slewing operation lever is operated in the direction of facing the upper slewing body 3 to the target construction surface. For example, when the slewing operation lever is operated in the direction in which the difference between the target angle and the current turning angle increases, the automatic control unit 54 determines that the slewing operation lever is not operated in the direction of facing the upper slewing body 3 to the target construction surface, and does not execute the facing control. On the other hand, when the slewing operation lever is operated in the direction in which the difference between the target angle and the current turning angle decreases, the automatic control unit 54 determines that the slewing operation lever is operated in the direction of facing the upper slewing body 3 to the target construction surface, and executes the facing control. As a result, the slewing hydraulic motor 2A can be operated so that the difference between the target angle and the current turning angle becomes smaller. After that, when the difference between the target angle and the current turning angle becomes less than or equal to a predetermined value or zero, the automatic control unit 54 stops the slewing hydraulic motor 2A.

[0107] The case shown in FIG. 7B is one example showing a state where the attachment operation surface AF includes the normal line (virtual cylindrical body CB). The angle α formed between the line segment L1 indicating the direction of the target construction surface and the line segment L2 indicating the longitudinal axis of the upper swing body 3 is 90°. However, if the attachment operation surface AF includes the normal line (virtual cylindrical body CB), the angle α does not necessarily have to be 90°. For example, since the ground on which the excavator 100 is installed is often a ground with large undulations, even when the attachment operation surface AF includes the normal line (virtual cylindrical body CB), the angle α does not always become 90°.

[0108] Based on the descriptions regarding FIGS. 7A, 7B, 8A, and 8B above, referring to FIG. 6 again, the process of the facing process will be described.

[0109] First, the machine guidance device 50 included in the controller 30 determines whether a facing deviation has occurred. In the present embodiment, the machine guidance device 50 determines whether a facing deviation has occurred based on the information regarding the target construction surface pre-stored in the storage device 47 and the output of the positioning device P1 as the direction detection device. The information regarding the target construction surface includes information regarding the direction of the target construction surface. The positioning device P1 outputs information regarding the direction of the upper swing body 3. For example, as shown in FIG. 8A, when the attachment operation surface AF does not include the normal line of the target construction surface, the machine guidance device 50 determines that a facing deviation has occurred between the target construction surface and the excavator 100. In such a state, as shown in FIG. 7A, the angle α formed between the line segment L1 representing the direction of the target construction surface and the line segment L2 representing the direction of the upper swing body 3 is an angle other than 90°.

[0110] Note that the machine guidance device 50 may determine whether a front alignment deviation has occurred based on the image captured by the camera S6. For example, the machine guidance device 50 may perform various image processes on the image captured by the camera S6 to derive information regarding the shape of the slope surface that is the work target, and determine whether a front alignment deviation has occurred based on the derived information. Alternatively, the machine guidance device 50 may determine whether a front alignment deviation has occurred based on the output of another space recognition device other than the camera S6, such as an ultrasonic sensor, a millimeter-wave radar, a distance image sensor, a LIDAR, or an infrared sensor.

[0111] When it is determined that a front alignment deviation has occurred, the machine guidance device 50 determines whether the swing operation lever has been operated in the direction of aligning the upper swing body 3 with the target construction surface with a predetermined switch pressed (steps ST1, ST2).

[0112] When the predetermined switch is pressed (YES in step ST1) and the swing operation lever is being operated in the direction of aligning the upper swing body 3 with the target construction surface (YES in step ST2), the machine guidance device 50 determines whether the target construction surface is directly below the bucket 6 based on the position of the bucket 6 calculated by the position calculation unit 51 (step ST3).

[0113] At this time, it may be determined whether there are any obstacles around the excavator 100. For example, the machine guidance device 50 performs image recognition processing on the image captured by the camera S6 to determine whether there is an image related to a predetermined obstacle in the captured image. The predetermined obstacle is, for example, at least one of a person, an animal, a machine, a building, and the like. And when it is determined that there is no image related to the predetermined obstacle in the image related to the predetermined range set around the excavator 100, it is determined that there is no obstacle around the excavator 100. The predetermined range includes, for example, a range where an object that may come into contact with the excavator 100 when the excavator 100 is moved to face the target construction surface with the upper swing body 3. The range RA represented by the cross-hatching pattern in FIG. 7A is an example of the predetermined range. However, the predetermined range may be set as a wider range, for example, within a range of a predetermined distance from the swing axis 2X.

[0114] The machine guidance device 50 may also determine whether there are any obstacles around the excavator 100 based on the output of another spatial recognition device other than the camera S6, such as an ultrasonic sensor, a millimeter-wave radar, a distance image sensor, a LIDAR, or an infrared sensor.

[0115] While a predetermined switch is pressed, the swing operation lever is operated in a direction to face the upper swing body 3 toward the target construction surface, and when the target construction surface is directly below the bucket 6 (YES in step ST3), the machine guidance device 50 executes alignment control (step ST4). In the examples of FIGS. 7A, 7B, 8A, and 8B, the automatic control unit 54 of the machine guidance device 50 outputs a current command to the proportional valve 31CL (see FIG. 4C). Then, the pilot pressure generated by the hydraulic oil flowing out of the pilot pump 15 and passing through the proportional valve 31CL and the shuttle valve CL acts on the left pilot port of the control valve 173. The control valve 173 displaced rightward allows the hydraulic oil discharged from the main pump 14L to flow into the first port 2A1 of the swing hydraulic motor 2A. Further, the control valve 173 allows the hydraulic oil flowing out of the second port 2A2 of the swing hydraulic motor 2A to flow out to the hydraulic oil tank. As a result, the swing hydraulic motor 2A rotates in the forward direction, and a swing force is applied to the upper swing body 3 around the swing axis 2X as shown by the arrow in FIG. 7A to swing the upper swing body 3 leftward. Thereafter, as shown in FIG. 7B, when the angle α becomes 90 degrees, or when the angle β becomes 0 degrees, the automatic control unit 54 stops outputting the current command to the proportional valve 31CL and reduces the pilot pressure acting on the left pilot port of the control valve 173. The control valve 173 is displaced leftward and returns to the neutral position, blocking the flow of hydraulic oil from the main pump 14L toward the first port 2A1 of the swing hydraulic motor 2A. Further, the control valve 173 blocks the flow of hydraulic oil from the second port 2A2 of the swing hydraulic motor 2A toward the hydraulic oil tank. As a result, the swing hydraulic motor 2A stops rotating in the forward direction, and the leftward swing of the upper swing body 3 is stopped.

[0116] In addition, when determining whether there are any obstacles around the excavator 100, if it is determined that there are obstacles around the excavator 100, the machine guidance device 50 may end the current alignment process without performing the alignment control. This is to prevent the excavator 100 from coming into contact with the obstacles due to the execution of the alignment control. In this case, the machine guidance device 50 may output an alarm. Further, the machine guidance device 50 may transmit information about the obstacles, such as the presence or absence of obstacles, the position of the obstacles, and the type of the obstacles, to an external device via the communication device T1. Also, the machine guidance device 50 may receive information about the obstacles acquired by other excavators via the communication device T1.

[0117] In this way, the controller 30 can execute the alignment control to align the upper swing body 3 with the target construction surface by applying a turning force to the upper swing body 3 to turn it.

[0118] Further, as described above, the controller 30 is configured to execute the alignment control when a predetermined switch is operated. For example, it may be configured to execute the alignment control when the MC switch is operated. In this case, when the MC switch for starting the machine control function is pressed, the controller 30 can automatically align the upper swing body 3 with the target construction surface. That is, the controller 30 can execute the alignment control as part of the machine control function. Therefore, when the machine control function is executed, the controller 30 can reduce the annoyance felt by the operator of the excavator 100 when aligning the excavator 100 with the target construction surface. As a result, the controller 30 can improve the working efficiency of the excavator 100. In this way, while a predetermined switch is being operated, an operation for swinging the upper swing body 3 is performed, and alignment control may be performed when there is a target construction surface below the operating elements of the excavator 100 for constructing the target construction surface such as the bucket 6. Thereby, it is possible to assist the operator in attempting to align the upper swing body 3 with the target construction surface only when there is a target construction surface below the operating elements of the excavator 100 for constructing the target construction surface such as the bucket 6. Further, if the switch for pressing when performing automatic control of the attachment other than the alignment control and the switch for pressing when performing the alignment control are the same switch, after performing the alignment control by operating the swing operation lever while pressing the switch to align the upper swing body 3 with the target construction surface, automatic control can be performed by operating another lever while continuously pressing the switch. Thereby, the alignment control and the automatic control can be performed in a series of operations.

[0119] In the above-described alignment control, by improving the alignment accuracy, the work can be performed accurately and the work efficiency can be improved. Therefore, the control for improving the alignment accuracy will be described below.

[0120] FIG. 9A is a flowchart for explaining an example of the process added to the alignment control.

[0121] In this process, when starting the alignment control, the automatic control unit 54 determines whether the turning speed of the upper slewing body 3 calculated by the turning speed calculation unit 57 exceeds a predetermined speed (step ST11). As described above, the alignment control is started when there is a target construction surface directly below the bucket 6. Therefore, even if the turning speed of the upper slewing body 3 in the alignment control is predetermined, the turning speed of the upper slewing body 3 may be high when there is no target construction surface directly below the bucket 6. In that case, if the alignment control continues, there is a risk that the upper slewing body 3 cannot stop at the alignment position with the target construction surface. Therefore, when starting the alignment control, the automatic control unit 54 first calculates the turning angle of the upper slewing body 3 calculated by the position calculation unit 51 and the distance between the tip of the bucket 6 and the target construction surface calculated by the distance calculation unit 52, and uses them to calculate the turning angle required for the upper slewing body 3 to face the target construction surface. When the turning angle required for the upper slewing body 3 to face the target construction surface is small, since the angle turned at the limited turning speed is small, if the turning speed before being limited is large, the turning speed may not decrease sufficiently until the upper slewing body 3 faces the target construction surface, and the possibility that the upper slewing body 3 exceeds the alignment position with the target construction surface increases. On the other hand, when the turning angle required for the upper slewing body 3 to face the target construction surface is large, since the angle turned at the limited turning speed is large, even if the turning speed before being limited is large, the turning speed decreases sufficiently until the upper slewing body 3 faces the target construction surface, and the possibility that the upper slewing body 3 exceeds the alignment position with the target construction surface decreases. Therefore, the automatic control unit 54 sets a predetermined speed, which is a condition for limiting the turning speed of the upper slewing body 3, to be faster as the turning angle of the upper slewing body 3 is smaller.

[0122] Also, in the turning speed calculation unit 57, the turning speed of the upper slewing body 3 is calculated by time-differentiating the turning angle of the upper slewing body 3 calculated by the position calculation unit 51. Therefore, the automatic control unit 54 can determine whether the turning speed of the upper slewing body 3 calculated by the turning speed calculation unit 57 exceeds a predetermined speed obtained according to the turning angle required for the upper slewing body 3 to face the target construction surface.

[0123] When the turning speed of the upper swing body 3 exceeds a predetermined speed (YES in step ST11), the automatic control unit 54 restricts the turning speed of the upper swing body 3 (step ST12). Specifically, the automatic control unit 54 changes the pilot pressure that exits from the pilot pump 15 and acts on the control valve 173 via the proportional valve 31CL and the shuttle valve CL, thereby reducing the amount of hydraulic oil flowing into the swing hydraulic motor 2A. As a result, the turning force applied to the upper swing body 3 decreases, and the turning speed of the upper swing body 3 slows down. Note that the degree to which the automatic control unit 54 slows down the turning speed of the upper swing body 3 may be set according to the turning angle required until the upper swing body 3 faces the target construction surface, and further according to the 100 types and sizes of the excavator 100. Also, instead of slowing down the turning speed of the upper swing body 3 by changing the pilot pressure that exits from the pilot pump 15 and acts on the control valve 173 via the proportional valve 31CL and the shuttle valve CL, a resistance force in the direction opposite to the operation direction may be applied to the lever of the operating device 26 being operated in the turning operation, and the turning speed of the upper swing body 3 may be controlled to slow down by restricting the operation amount of the lever.

[0124] As described above, the excavator 100 in this embodiment includes a lower traveling body 1, an upper slewing body 3 that is rotatably mounted on the lower traveling body 1, and a controller 30 that performs alignment control to make the upper slewing body 3 face the target construction surface by applying a turning force to the upper slewing body 3 to turn it. The controller 30 controls the turning speed of the upper slewing body 3 based on the turning angle required until the upper slewing body 3 faces the target construction surface. Thereby, in the alignment control for making the upper slewing body 3 face the target construction surface, it becomes difficult for the upper slewing body 3 to exceed the alignment position with the target construction surface, and the accuracy of the alignment control can be improved. For example, when the turning speed of the upper slewing body 3 exceeds a predetermined speed, the controller 30 can improve the accuracy of the alignment control by limiting the turning speed of the upper slewing body 3. Also, at this time, by obtaining the predetermined speed, which is a condition for limiting the turning speed of the upper slewing body 3, based on the turning angle required until the upper slewing body 3 faces the target construction surface, regardless of the magnitude of the inertial force due to turning when the upper slewing body 3 turns and faces the target construction surface, it is possible to make it difficult for the upper slewing body 3 to exceed the alignment position with the target construction surface in the alignment control for making the upper slewing body 3 face the target construction surface.

[0125] Further, the automatic control unit 54 determines whether the upper slewing body 3 is likely to exceed the alignment position with the target construction surface in the alignment control (step ST13). Here, the controller 30 calculates the distance between the tip of the bucket 6 and the target construction surface by the distance calculation unit 52. Therefore, the automatic control unit 54 constantly determines whether the upper slewing body 3 is likely to exceed the alignment position with the target construction surface based on the distance calculated by the distance calculation unit 52.

[0126] And when the upper swing body 3 is likely to exceed the directly facing position with the target construction surface (YES in step ST13), in the information transmission unit 53, it is notified to the operator of the excavator 100 that the upper swing body 3 is likely to exceed the directly facing position with the target construction surface (step ST14). The notification at this time may be performed using, for example, the sound from the sound output device 43. Also, it may be performed using characters or images via the display device 40. In this way, when the controller 30 notifies the operator of the excavator 100 when the upper swing body 3 is likely to exceed the directly facing position with the target construction surface due to the rotation of the upper swing body 3, the operator of the excavator 100 can be made to recognize that the upper swing body 3 is likely to exceed the directly facing position with the target construction surface due to the rotation of the upper swing body 3 in the direct facing control.

[0127] Further, the automatic control unit 54 constantly determines whether the upper swing body 3 has exceeded the directly facing position with the target construction surface based on the distance calculated by the distance calculation unit 52 (step ST15).

[0128] And when the upper swing body 3 has exceeded the directly facing position with the target construction surface (YES in step ST15), in the information transmission unit 53, it is notified to the operator of the excavator 100 that the upper swing body 3 has exceeded the directly facing position with the target construction surface (step ST16). The notification at this time may be performed using, for example, the sound from the sound output device 43. Also, it may be performed using characters or the like via the display device 40. In this way, when the controller 30 notifies the operator of the excavator 100 when the upper swing body 3 has exceeded the directly facing position with the target construction surface due to the rotation of the upper swing body 3, the operator of the excavator 100 can be made to recognize that the upper swing body 3 has exceeded the directly facing position with the target construction surface due to the rotation of the upper swing body 3 in the direct facing control.

[0129] Note that the information transmission unit 53 may use different sounds when the upper swing body 3 is about to exceed the facing position with the target construction surface and when the upper swing body 3 has exceeded the facing position with the target construction surface. For example, when the upper swing body 3 is about to exceed the facing position with the target construction surface, the information transmission unit 53 may perform a first notification using an intermittent sound via the sound output device 43, and when the upper swing body 3 has exceeded the facing position with the target construction surface, the information transmission unit 53 may perform a second notification using a continuous sound via the sound output device 43. Thereby, the operator can distinguish and recognize the case where the upper swing body 3 is about to exceed the facing position with the target construction surface and the case where the upper swing body 3 has exceeded the facing position with the target construction surface.

[0130] In this embodiment, after restricting the turning speed of the upper swing body 3 in step ST12, it is determined whether the upper swing body 3 is about to exceed the facing position with the target construction surface or has exceeded it, and the notifications in steps ST14 and ST16 are performed. However, the notifications in steps ST14 and ST16 may be performed without restricting the turning speed of the upper swing body 3 in step ST12. In that case, in the flow shown in FIG. 9A, the processes in steps ST13 and ST15 may be performed without performing the processes in steps ST11 and ST12, or when the determination in step ST11 is NO, the processes in steps ST13 and ST15 may be shifted to. Even in that case, in the facing control, when the upper swing body 3 turns and is about to exceed the facing position with the target construction surface or has exceeded the facing position, the operator of the excavator 100 can be made to recognize that fact.

[0131] Next, an example of a method for restricting the turning speed of the upper swing body 3 will be described.

[0132] FIG. 9B is a flowchart for explaining an example of a method for restricting the turning speed of the upper swing body 3.

[0133] In this process, when starting the facing control, the automatic control unit 54 determines whether the turning speed of the upper swing body 3 exceeds a predetermined speed (step ST21), and then determines whether the difference between the turning speed of the upper swing body 3 and the predetermined speed is greater than a predetermined value (step ST22).

[0134] And when the difference between the turning speed of the upper swing body 3 and the predetermined speed is equal to or less than the predetermined value (NO in step ST22), the automatic control unit 54 changes the pilot pressure acting on the control valve 173 from the pilot pump 15 via the proportional valve 31CL and the shuttle valve CL as described above, thereby reducing the amount of hydraulic oil flowing into the turning hydraulic motor 2A. As a result, the turning force applied to the upper swing body 3 is reduced and the turning speed of the upper swing body 3 is slowed down (step ST23).

[0135] On the other hand, when the difference between the turning speed of the upper swing body 3 and the predetermined speed is greater than the predetermined value (YES in step ST22), there is a possibility that the automatic control unit 54 cannot slow down the turning speed of the upper swing body 3 to the target turning speed. Therefore, when the difference between the turning speed of the upper swing body 3 and the predetermined speed is greater than the predetermined value, the automatic control unit 54 applies a turning force in the direction opposite to the current turning force applied to the upper swing body 3 (step ST24). Specifically, when a pilot pressure is acting on the left pilot port of the control valve 173 to turn the upper swing body 3, the pilot pressure generated by the hydraulic oil flowing from the pilot pump 15 through the proportional valve 31CL and the shuttle valve CL is made to act on the right pilot port of the control valve 173. The control valve 173 receiving the pilot pressure at the right pilot port is displaced to the left, and the hydraulic oil discharged from the main pump 14L flows into the second port 2A2 of the turning hydraulic motor 2A. Further, the control valve 173 causes the hydraulic oil flowing out from the first port 2A1 of the turning hydraulic motor 2A to flow out to the hydraulic oil tank. As a result, the turning hydraulic motor 2A rotates in the reverse direction. At this time, although a turning force in the reverse direction is applied to the upper swing body 3, due to the inertial force of the previous turning of the upper swing body 3, the upper swing body 3 does not turn in the reverse direction for a while.

[0136] After that, after the turning speed of the upper swing body 3 has slowed down to or approached the target turning speed, the addition of the reverse turning force to the upper swing body 3 is stopped.

[0137] In this way, in this example, when the difference between the current turning speed of the upper swing body 3 and the predetermined speed when the controller 30 starts the facing control is greater than a predetermined value, the controller 30 applies a turning force to the upper swing body 3 that is opposite to the turning force currently applied to the upper swing body 3. Thereby, even when the difference between the turning speed of the upper swing body 3 and the predetermined speed when starting the facing control is greater than the predetermined value, the possibility that the automatic control unit 54 cannot slow down the turning speed of the upper swing body 3 to the target turning speed can be reduced.

[0138] Next, another example of improving the facing accuracy will be described.

[0139] FIG. 9C is a flowchart for explaining another example of the process added to the facing control.

[0140] Also in this process, similar to the flow shown in FIG. 9A, when starting the facing control, the automatic control unit 54 determines whether the turning speed of the upper swing body 3 exceeds a predetermined speed (step ST31). If the turning speed of the upper swing body 3 exceeds the predetermined speed, the turning speed of the upper swing body 3 is limited (step ST32).

[0141] Further, as described above, the automatic control unit 54 constantly determines whether the upper swing body 3 has exceeded the facing position with the target construction surface based on the distance calculated by the distance calculation unit 52 (step ST33).

[0142] When the upper revolving body 3 exceeds the facing position with the target construction surface (YES in step ST33), the automatic control unit 54 applies a turning force in the direction opposite to the current turning force applied to the upper revolving body 3. Specifically, when pilot pressure acts on the left pilot port of the control valve 173 to turn the upper revolving body 3, the pilot pressure generated by the hydraulic oil flowing out of the pilot pump 15 and passing through the proportional valve 31CL and the shuttle valve CL is applied to the right pilot port of the control valve 173. The control valve 173 receiving the pilot pressure at the right pilot port is displaced leftward, and the hydraulic oil discharged by the main pump 14L flows into the second port 2A2 of the swing hydraulic motor 2A. Also, the control valve 173 causes the hydraulic oil flowing out from the first port 2A1 of the swing hydraulic motor 2A to flow out to the hydraulic oil tank. As a result, the swing hydraulic motor 2A rotates in the reverse direction. At this time, a turning force in the opposite direction is applied to the upper revolving body 3. Also, since the turning speed of the upper revolving body 3 is slow due to the speed limit in step ST32, the upper revolving body 3 turns in the reverse direction (step ST34).

[0143] After that, the automatic control unit 54 performs alignment control until the upper revolving body 3 faces the target construction surface (step ST35).

[0144] In this way, in this example, when the controller 30 determines that the upper revolving body 3 has exceeded the facing position with the target construction surface due to the turning of the upper revolving body 3, the upper revolving body 3 is turned in the reverse direction until the upper revolving body 3 faces the target construction surface. Thereby, even when the upper revolving body 3 exceeds the facing position with the target construction surface due to the turning of the upper revolving body 3, the upper revolving body 3 can be made to face the target construction surface.

[0145] In this example, when the upper revolving body 3 exceeds the facing position with the target construction surface, the upper revolving body 3 is revolved in the reverse direction under the control of the automatic control unit 54. However, when the upper revolving body 3 exceeds the facing position with the target construction surface, the upper revolving body 3 may be revolved in the reverse direction by operating the operating device 26 until the upper revolving body 3 faces the target construction surface. In such a configuration, in the facing control, when the upper revolving body 3 stops at the facing position with the target construction surface, even if a turning operation is performed by operating the lever while pressing a predetermined switch, the upper revolving body 3 maintains the facing state without revolving. On the other hand, when the upper revolving body 3 exceeds the facing position with the target construction surface, when a turning operation in the direction in which the upper revolving body 3 faces the target construction surface is performed by operating the lever of the operating device 26, the upper revolving body 3 will revolve in the direction in which it faces the target construction surface.

[0146] Also, in this embodiment, when the revolving speed of the lower traveling body 1 or the upper revolving body 3 at the start of the facing control exceeds a predetermined speed, the controller 30 limits their revolving speeds. However, when the revolving angle required until the upper revolving body 3 faces the target construction surface is large and the turning operation amount for the operating device 26 is large, the inertial force due to turning becomes large, and there may be a case where the revolving speed of the lower traveling body 1 or the upper revolving body 3 exceeds the predetermined speed even during the execution of the facing control. Even in that case, similar to this embodiment, the controller 30 will limit the revolving speed of the lower traveling body 1 or the upper revolving body 3.

[0147] Note that the controller 30 may also make the upper revolving body 3 face the target construction surface by operating other actuators. For example, as shown in FIGS. 10A and 10B, the controller 30 may make the upper revolving body 3 face the target construction surface by automatically operating the left traveling hydraulic motor 1L and the right traveling hydraulic motor 1R.

[0148] FIG. 10A and FIG. 10B are top views of the excavator 100 when the facing process is executed, corresponding to FIGS. 7A and 7B. That is, FIG. 10A shows a state where the upper swing body 3 is not facing the target construction surface, and FIG. 10B shows a state where the upper swing body 3 is facing the target construction surface.

[0149] In the examples of FIGS. 10A and 10B, the controller 30 rotates the right travel hydraulic motor 1R forward and the left travel hydraulic motor 1L backward to perform a super-close turning, so as to align the upper swing body 3 with the target construction surface.

[0150] In such a configuration, it includes a lower traveling body 1, an upper swing body 3 rotatably mounted on the lower traveling body 1, and a controller 30 that performs a facing control to align the upper swing body 3 with the target construction surface by applying a turning force to the lower traveling body 1 to turn it. When the current turning speed of the lower traveling body 1 exceeds a predetermined speed, the controller 30 will limit the turning speed of the lower traveling body 1.

[0151] In the above-described embodiment, a hydraulic operating device is adopted as the operating device 26, but an electric operating device may also be adopted.

[0152] FIG. 11 shows a configuration example of an operating system including an electric operating device.

[0153] Specifically, the operating system of FIG. 11 is an example of a boom operating system, mainly including a pilot pressure actuated control valve 17, a boom operating lever 26A as an electric operating lever, a controller 30, a solenoid valve 60 for boom raising operation, and a solenoid valve 62 for boom lowering operation. The operating system of FIG. 11 can be similarly applied to an arm operating system, a bucket operating system, etc.

[0154] As shown in FIG. 3, the pilot pressure-operated control valve 17 includes control valves 175L and 175R for the boom cylinder 7. The solenoid valve 60 is configured to be able to adjust the flow passage area of the oil passage connecting the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R, respectively. The solenoid valve 62 is configured to be able to adjust the flow passage area of the oil passage connecting the pilot pump 15 to the right pilot port of the control valve 175R.

[0155] When manual operation is performed, the controller 30 generates a boom raising operation signal (electrical signal) or a boom lowering operation signal (electrical signal) according to the operation signal (electrical signal) output by the operation signal generation unit of the boom operation lever 26A. The operation signal output by the operation signal generation unit of the boom operation lever 26A is an electrical signal that changes according to the operation amount and operation direction of the boom operation lever 26A.

[0156] Specifically, when the boom operation lever 26A is operated in the boom raising direction, the controller 30 outputs a boom raising operation signal (electrical signal) corresponding to the lever operation amount to the solenoid valve 60. The solenoid valve 60 adjusts the flow passage area according to the boom raising operation signal (electrical signal) and controls the pilot pressure acting on the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. Similarly, when the boom operation lever 26A is operated in the boom lowering direction, the controller 30 outputs a boom lowering operation signal (electrical signal) corresponding to the lever operation amount to the solenoid valve 62. The solenoid valve 62 adjusts the flow passage area according to the boom lowering operation signal (electrical signal) and controls the pilot pressure acting on the right pilot port of the control valve 175R.

[0157] When performing automatic control, the controller 30 generates a boom raising operation signal (electrical signal) or a boom lowering operation signal (electrical signal) according to a correction operation signal (electrical signal), instead of the operation signal output by the operation signal generation unit of the boom operation lever 26A. The correction operation signal may be an electrical signal generated by the machine guidance device 50, or an electrical signal generated by a control device other than the machine guidance device 50.

Explanation of Signs

[0158] 1 Lower traveling body 1L Left traveling hydraulic motor 1R Right traveling hydraulic motor 2 Slewing mechanism 2A Slewing hydraulic motor 3 Upper slewing body 4 Boom 5 Arm 6 Bucket 7 Boom cylinder 8 Arm cylinder 9 Bucket cylinder 10 Cabin 11 Engine 13, 13L, 13R Regulator 14, 14L, 14R Main pump 15 Pilot pump 17 Control valve 18L, 18R Throttle 19L, 19R Control pressure sensor 26 Operating device 26A Boom operation lever 26B Bucket operation lever 26C Slewing operation lever 28, 28L, 28R Discharge pressure sensor 29, 29A, 29B, 29C Operating pressure sensor 30 Controller 31, 31AL, 31AR, 31BL, 31BR, 31CL, 31CR Proportional valve 32, 32AL, 32AR, 32BL, 32BR, 32CL, 32CR Shuttle valve 40 Display device 42 Input device 43, A2 Sound output device 47 Memory device 50 Machine guidance device 51 Position calculation unit 52 Distance calculation unit 53 Information transmission unit 54 Automatic control unit 55 Swivel angle calculation unit 56 Relative angle calculation unit 57 Swivel speed calculation unit 60, 62 Solenoid valve 171 - 174, 175L, 175R, 176L, 176R Control valve RC Remote operation room S1 Boom angle sensor S2 Arm angle sensor S3 Bucket angle sensor S4 Machine body tilt sensor S5 Swivel angular velocity sensor S6 Camera S6B Rear camera S6F Front camera S6L Left camera S6R Right camera P1 Positioning device T1 Communication device

Claims

1. A lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, and a control device that performs alignment control to align the upper slewing body with a target construction surface by applying a turning force to the lower traveling body or the upper slewing body to cause turning. The excavator is provided with: The control device controls the turning speed of the lower traveling body or the upper slewing body based on the turning angle required until the upper slewing body faces the target construction surface.

2. The excavator according to claim 1, wherein the control device limits the turning speed when the turning speed of the lower traveling body or the upper slewing body exceeds a predetermined speed.

3. The excavator according to claim 2, wherein the predetermined speed is obtained based on the turning angle required until the upper slewing body faces the target construction surface.

4. When the difference between the turning speed of the lower traveling body or the upper slewing body at the start of the alignment control and the predetermined speed is greater than a predetermined value, the control device applies a turning force in the direction opposite to the current turning force applied to the lower traveling body or the upper slewing body to which the turning force is applied. The excavator according to claim 2.

5. The excavator according to claim 1, wherein the control device notifies the operator of the excavator when the upper slewing body is likely to exceed the alignment position with the target construction surface due to the turning of the lower traveling body or the upper slewing body.

6. The excavator according to claim 1, wherein the control device notifies the operator of the excavator when the upper slewing body exceeds the alignment position with the target construction surface due to the turning of the lower traveling body or the upper slewing body.

7. When the upper slewing body is likely to exceed the alignment position with the target construction surface due to the turning of the lower traveling body or the upper slewing body, the control device gives a first notification to the operator of the excavator, and when the upper slewing body exceeds the alignment position with the target construction surface due to the turning of the lower traveling body or the upper slewing body, the control device gives a second notification in a manner different from the first notification to the operator of the excavator. The excavator according to claim 1.

8. The excavator according to claim 1, wherein when the upper slewing body exceeds the facing position with the target construction surface due to the lower traveling body or the upper slewing body slewing, the control device slews the lower traveling body or the upper slewing body in the reverse direction until the upper slewing body faces the target construction surface.

9. The excavator according to claim 1, wherein the control device performs the facing control when an operation for slewing the lower traveling body or the upper slewing body is performed while a predetermined switch is being operated, and when the target construction surface is below an operating element of the excavator that constructs the target construction surface.

10. A lower traveling body, An upper slewing body rotatably mounted on the lower traveling body, A control device that performs facing control to face the upper slewing body to a target construction surface by applying a turning force to the lower traveling body or the upper slewing body to cause turning, The excavator, wherein the control device gives a notification when the upper slewing body is likely to exceed the facing position with the target construction surface due to the lower traveling body or the upper slewing body slewing.

Images