JP7289701B2 - Excavator - Google Patents

Description

The present disclosure relates to excavators.

For example, a front attachment consisting of a link mechanism including a bucket and a boom, and a series of operation states from excavation by this front attachment to earth dumping and return turning are detected, and the load acting on the bucket during this operation is measured. a controller unit, measuring the load acting on the bucket within the time from the end of excavation to the start of earth dumping, and measuring the load acting on the bucket again within the time from the end of earth dumping to the start of excavation, A method for calculating the amount of soil to be operated for a hydraulic excavator is known, which is characterized in that the amount of soil to be operated during excavation work is calculated by obtaining the difference between these two loads (see Patent Document 1).

JP-A-2002-4337

However, in the method disclosed in Patent Document 1, since the center of gravity of the soil in the bucket is the center of gravity of the bucket, there is a possibility that the accuracy of detecting the weight of the soil will decrease when the center of gravity of the soil differs.

Therefore, in view of the above problems, it is an object of the present invention to provide a shovel that can accurately calculate the weight of a load.

In order to achieve the above object, in one embodiment of the present invention, there is provided a lower traveling body, an upper rotating body mounted on the lower traveling body so as to be capable of turning via a rotating mechanism, and a boom attached to the upper rotating body. an attachment having an arm and a bucket; an imaging device that captures an image of a load loaded on the bucket; and a control device. a weight calculation unit that calculates the weight of the load based on the weight center of the load that has been calculated, and the center-of-gravity calculation unit calculates the weight of the load based on at least one of the type and state of the load. estimating the shape of the upper surface of the load, and based on the shape of the load imaged by the imaging device , the estimated shape of the upper surface of the load, and shape information of the inner surface of the bucket; A shovel is provided that estimates the overall shape of an object and calculates the center of gravity of the load based on the estimated overall shape of the load.

According to the above-described embodiment, it is possible to provide a shovel that accurately calculates the weight of a load.

1 is a side view of a shovel as an excavator according to this embodiment; FIG. It is a figure showing roughly an example of composition of a shovel concerning this embodiment. It is a figure showing roughly an example of composition of a hydraulic system of an excavator concerning this embodiment. FIG. 2 is a diagram schematically showing an example of a component related to an operation system in the hydraulic system of the excavator according to the present embodiment; It is a figure which shows roughly an example of the structural part regarding the earth-and-sand load detection function of the excavators which concern on this embodiment. FIG. 4 is a partially enlarged view for explaining the relationship of forces acting on the bucket; FIG. 11 is a schematic diagram illustrating a third center-of-gravity calculation method by the load center-of-gravity calculator. FIG. 11 is a schematic diagram for explaining a fourth center-of-gravity calculation method by the load center-of-gravity calculator.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

[Overview of Excavator]
First, an outline of a shovel 100 according to this embodiment will be described with reference to FIG.

FIG. 1 is a side view of a shovel 100 as an excavator according to this embodiment.

In FIG. 1, the excavator 100 is positioned on a horizontal plane facing the upsloping surface ES to be constructed, and an upslope BS that is an example of a target construction surface to be described later (that is, an upsloping surface BS after construction on the upsloping surface ES). slope shape) is also described. A cylindrical body (not shown) indicating the normal direction of the upslope BS, which is the target construction surface, is provided on the upsloping surface ES to be constructed.

The excavator 100 according to the present embodiment includes a lower traveling body 1, an upper rotating body 3 mounted on the lower traveling body 1 so as to be rotatable via a rotating mechanism 2, a boom 4 and an arm that constitute an attachment (working machine). 5, bucket 6, and cabin 10.

The lower traveling body 1 causes the excavator 100 to travel by hydraulically driving a pair of left and right crawlers by traveling hydraulic motors 1L and 1R (see FIG. 2, which will be described later). That is, a pair of traveling hydraulic motors 1L and 1R (an example of traveling motors) drives a lower traveling body 1 (crawler) as a driven portion.

The upper revolving structure 3 revolves with respect to the lower traveling structure 1 by being driven by a revolving hydraulic motor 2A (see FIG. 2, which will be described later). That is, the swing hydraulic motor 2A is a swing driving section that drives the upper swing body 3 as a driven section, and can change the orientation of the upper swing body 3. As shown in FIG.

Note that the upper swing body 3 may be electrically driven by an electric motor (hereinafter referred to as "swing electric motor") instead of the swing hydraulic motor 2A. In other words, the electric motor for turning is a turning driving portion that drives the upper turning body 3 as a non-driving portion, like the turning hydraulic motor 2A, and can change the orientation of the upper turning body 3 .

The boom 4 is pivotally attached to the center of the front portion of the upper rotating body 3 so as to be able to be raised. An arm 5 is pivotally attached to the tip of the boom 4 so as to be vertically rotatable. A bucket 6 is pivotally mounted so as to be vertically rotatable. The boom 4, arm 5, and bucket 6 are hydraulically driven by boom cylinders 7, arm cylinders 8, and bucket cylinders 9 as hydraulic actuators, respectively.

The bucket 6 is an example of an end attachment, and depending on the type of work, other end attachments such as slope buckets, dredging buckets, and breakers may be attached to the tip of the arm 5 instead of the bucket 6. etc. may be attached.

The cabin 10 is a driver's cab in which an operator boards, and is mounted on the front left side of the upper revolving structure 3 .

[Excavator configuration]
Next, a specific configuration of the excavator 100 according to the present embodiment will be described with reference to FIG. 2 in addition to FIG.

FIG. 2 is a diagram schematically showing an example of the configuration of the shovel 100 according to this embodiment.

In FIG. 2, the mechanical power system, hydraulic oil line, pilot line, and electrical control system are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively.

A drive system of the excavator 100 according to this embodiment includes an engine 11 , a regulator 13 , a main pump 14 and a control valve 17 . Further, the hydraulic drive system of the excavator 100 according to the present embodiment includes traveling hydraulic motors 1L and 1R that hydraulically drive the lower traveling body 1, the upper revolving body 3, the boom 4, the arm 5, and the bucket 6, respectively, as described above. , swing hydraulic motor 2A, boom cylinder 7, arm cylinder 8, bucket cylinder 9 and other hydraulic actuators.

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

The regulator 13 controls the discharge amount of the main pump 14 . For example, the regulator 13 adjusts the angle (tilt angle) of the swash plate of the main pump 14 according to a control command from the controller 30 . The regulator 13 includes, for example, regulators 13L and 13R as described later.

The main pump 14 is mounted, for example, on the rear part of the upper rotating body 3, similarly to the engine 11, and supplies working oil to the control valve 17 through a high-pressure hydraulic line. The main pump 14 is driven by the engine 11 as described above. The main pump 14 is, for example, a variable displacement hydraulic pump, and as described above, under the control of the controller 30, the regulator 13 adjusts the tilting angle of the swash plate, thereby adjusting the stroke length of the piston and discharging. The flow rate (discharge pressure) is controlled. The main pump 14 includes, for example, main pumps 14L and 14R as described later.

The control valve 17 is, for example, a hydraulic control device that is mounted at the center of the upper revolving body 3 and that controls the hydraulic drive system according to the operation of the operation device 26 by the operator. As described above, the control valve 17 is connected to the main pump 14 via the high-pressure hydraulic line, and operates the hydraulic fluid supplied from the main pump 14 according to the operating state of the operating device 26 to the hydraulic actuator (traveling hydraulic motor 1L). , 1R, swing hydraulic motor 2A, boom cylinder 7, arm cylinder 8, and bucket cylinder 9). Specifically, the control valve 17 includes control valves 171 to 176 that control the flow rate and flow direction of hydraulic oil supplied from the main pump 14 to each hydraulic actuator. More specifically, the control valve 171 corresponds to the traveling hydraulic motor 1L, the control valve 172 corresponds to the traveling hydraulic motor 1R, and the control valve 173 corresponds to the turning hydraulic motor 2A. A control valve 174 corresponds to the bucket cylinder 9 , a control valve 175 corresponds to the boom cylinder 7 , and a control valve 176 corresponds to the arm cylinder 8 . Further, the control valve 175 includes, for example, control valves 175L and 175R as described later, and the control valve 176 includes, for example, control valves 176L and 176R as described later. Details of the control valves 171 to 176 will be described later.

The operating system of the excavator 100 according to this embodiment includes a pilot pump 15 and an operating device 26 . The operation system of the excavator 100 also includes a shuttle valve 32 as a configuration related to a machine control function by the controller 30, which will be described later.

The pilot pump 15 is mounted, for example, on the rear portion of the upper revolving body 3 and supplies pilot pressure to the operating device 26 via a pilot line. The pilot pump 15 is, for example, a fixed displacement hydraulic pump, and is driven by the engine 11 as described above.

The operation device 26 is provided near the cockpit of the cabin 10, and is an operation input means for the operator to operate various operation elements (lower traveling body 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc.). is. In other words, the operating device 26 allows the operator to operate the hydraulic actuators (that is, the traveling hydraulic motors 1L and 1R, the turning hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, etc.) that drive the respective operating elements. is an operation input means for performing The operating device 26 is connected to the control valve 17 directly through its secondary pilot line, or indirectly through a shuttle valve 32 (to be described later) provided in the secondary pilot line. As a result, the control valve 17 can receive a pilot pressure corresponding to the operation state of the lower traveling body 1 , the upper swing body 3 , the boom 4 , the arm 5 , the bucket 6 and the like in the operating device 26 . Therefore, the control valve 17 can drive each hydraulic actuator according to the operating state of the operating device 26 . The operating device 26 includes, for example, a lever device that operates the arm 5 (arm cylinder 8). Further, the operation device 26 includes, for example, lever devices 26A to 26C that operate the boom 4 (boom cylinder 7), the bucket 6 (bucket cylinder 9), and the upper swing body 3 (swing hydraulic motor 2A) (see FIG. 4). reference). Further, the operating device 26 includes, for example, a lever device and a pedal device for operating the pair of left and right crawlers (traveling hydraulic motors 1L and 1R) of the lower traveling body 1, respectively.

The shuttle valve 32 has two inlet ports and one outlet port, and outputs to the outlet port the hydraulic fluid having the higher pilot pressure among the pilot pressures input to the two inlet ports. Shuttle valve 32 has two inlet ports, one of which is connected to operating device 26 and the other of which is connected to proportional valve 31 . The outlet port of shuttle valve 32 is connected through a pilot line to the pilot port of the corresponding control valve in control valve 17 (see FIG. 4 for details). 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. That is, the controller 30, which will be described later, causes the proportional valve 31 to output a pilot pressure that is higher than the secondary-side pilot pressure output from the operating device 26, so that the corresponding control can be performed regardless of the operation of the operating device 26 by the operator. Valves can be controlled to control the operation of various operating elements. The shuttle valves 32 include, for example, shuttle valves 32AL, 32AR, 32BL, 32BR, 32CL, 32CR as described later.

The operating device 26 (the left operating lever, the right operating lever, the left travel lever, and the right travel lever) may be of an electric type that outputs an electric signal instead of a hydraulic pilot type that outputs a pilot pressure. In this case, an electric signal from the operating device 26 is input to the controller 30, and the controller 30 controls each of the control valves 171 to 176 in the control valve 17 according to the input electric signal, thereby 26, various hydraulic actuators are operated according to the operation contents. For example, the control valves 171 to 176 in the control valve 17 may be electromagnetic solenoid type spool valves driven by commands from the controller 30 . Further, for example, electromagnetic valves that operate according to electrical signals from the controller 30 may be arranged between the pilot pump 15 and the pilot ports of the respective control valves 171-176. In this case, when a manual operation is performed using the electric operating device 26, the controller 30 controls the solenoid valve with an electric signal corresponding to the amount of operation (for example, the amount of lever operation) to increase or decrease the pilot pressure. By doing so, each of the control valves 171 to 176 can be operated in accordance with the content of the operation on the operation device 26 .

The control system of the excavator 100 according to the present embodiment includes a controller 30, a discharge pressure sensor 28, an operation pressure sensor 29, a proportional valve 31, a display device 40, an input device 42, an audio output device 43, a memory It includes a device 47, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, an aircraft tilt sensor S4, a turning state sensor S5, an imaging device S6, a positioning device P1, and a communication device T1.

A controller 30 (an example of a control device) is provided in, for example, the cabin 10 and performs drive control of the shovel 100 . The functions of the controller 30 may be realized by arbitrary hardware, software, or a combination thereof. For example, the controller 30 is mainly a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a nonvolatile auxiliary storage device, and various input/output interfaces. Configured. The controller 30 implements various functions by executing, on the CPU, various programs stored in, for example, a ROM or a nonvolatile auxiliary storage device.

For example, the controller 30 sets a target rotational speed based on a work mode or the like preset by a predetermined operation of an operator or the like, and performs drive control to rotate the engine 11 at a constant speed.

Further, for example, the controller 30 outputs a control command to the regulator 13 as necessary to change the discharge amount of the main pump 14 .

Further, for example, the controller 30 controls a machine guidance function that guides manual operation of the excavator 100 through the operating device 26 by the operator. The controller 30 also controls, for example, a machine control function that automatically assists the manual operation of the excavator 100 by the operator through the operating device 26 . That is, the controller 30 includes the machine guidance section 50 as a functional section related to the machine guidance function and the machine control function. The controller 30 also includes a sediment load processing unit 60, which will be described later.

Note that part of the functions of the controller 30 may be implemented by another controller (control device). That is, the functions of the controller 30 may be implemented in a manner distributed by a plurality of controllers. For example, the machine guidance function and machine control function may be realized by a dedicated controller (control device).

A discharge pressure sensor 28 detects the discharge pressure of the main pump 14 . A detection signal corresponding to the discharge pressure detected by the discharge pressure sensor 28 is taken into the controller 30 . The discharge pressure sensor 28 includes, for example, discharge pressure sensors 28L and 28R as described later.

As described above, the operation pressure sensor 29 detects the pilot pressure on the secondary side of the operation device 26, that is, the operation state (for example, the operation direction, the operation amount, etc.) related to each operating element (that is, the hydraulic actuator) in the operation device 26. Detects the pilot pressure corresponding to the operation content). A pilot pressure detection signal corresponding to the operation state of the lower traveling body 1 , the upper swing body 3 , the boom 4 , the arm 5 , the bucket 6 , etc. in the operating device 26 by the operation pressure sensor 29 is taken into the controller 30 . The operating pressure sensor 29 includes, for example, operating pressure sensors 29A to 29C as described later.

Instead of the operating pressure sensor 29, other sensors capable of detecting the operating state of each operating element in the operating device 26, such as the operating amount (tilting amount) and tilting direction of the lever devices 26A to 26C can be detected. Other encoders, potentiometers, etc. may be provided.

The proportional valve 31 is provided in a pilot line that connects the pilot pump 15 and the shuttle valve 32, and is configured to change its flow area (cross-sectional area through which hydraulic oil can flow). The proportional valve 31 operates according to control commands input from the controller 30 . As a result, even when the operator does not operate the operation device 26 (specifically, the lever devices 26A to 26C), the controller 30 controls the hydraulic oil discharged from the pilot pump 15 to the proportional valve 31 and the Via the shuttle valve 32 it can be fed to the corresponding control valve pilot port in the control valve 17 . The proportional valve 31 includes, for example, proportional valves 31AL, 31AR, 31BL, 31BR, 31CL, and 31CR as described later.

The display device 40 is provided at a location within the cabin 10 that is easily visible to a seated operator, and displays various information images under the control of the controller 30 . The display device 40 may be connected to the controller 30 via an in-vehicle communication network such as CAN (Controller Area Network), or may be connected to the controller 30 via a one-to-one dedicated line.

The input device 42 is provided within the cabin 10 within reach of a seated operator, receives various operation inputs from the operator, and outputs signals to the controller 30 according to the operation inputs. The input device 42 includes a touch panel mounted on the display of the display device that displays various information images, knob switches provided at the tips of the lever portions of the lever devices 26A to 26C, button switches provided around the display device 40, and levers. , toggles, rotary dials, etc. A signal corresponding to the operation content for the input device 42 is captured by the controller 30 .

The audio output device 43 is provided in the cabin 10, is connected to the controller 30, and outputs audio under the control of the controller 30, for example. The audio output device 43 is, for example, a speaker, buzzer, or the like. The audio output device 43 outputs various information as audio in response to an audio output command from the controller 30 .

The storage device 47 is provided, for example, in the cabin 10 and stores various information under the control of the controller 30 . 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 operation of the excavator 100, or may store information acquired via various devices before the excavator 100 starts operating. The storage device 47 may store data relating to the target construction surface acquired via the communication device T1 or the like or set via the input device 42 or the like, for example. The target construction plane may be set (stored) by the operator of the excavator 100, or may be set by the construction manager or the like.

The boom angle sensor S1 is attached to the boom 4 and measures the elevation angle of the boom 4 with respect to the upper rotating body 3 (hereinafter referred to as "boom angle"). Detect the angle formed by the straight line connecting the fulcrums at both ends. The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an IMU (Inertial Measurement Unit), and the like. The boom angle sensor S1 may also include a potentiometer using a variable resistor, a cylinder sensor that detects the stroke amount of the hydraulic cylinder (boom cylinder 7) corresponding to the boom angle, and the like. The same applies to the arm angle sensor S2 and the bucket angle sensor S3 below. A detection signal corresponding to the boom angle by the boom angle sensor S1 is taken into the controller 30 .

The arm angle sensor S2 is attached to the arm 5, and the rotation angle of the arm 5 with respect to the boom 4 (hereinafter referred to as "arm angle"), for example, the angle of the arm 5 with respect to a straight line connecting fulcrums at both ends of the boom 4 in a side view. Detects the angle formed by the straight line connecting the fulcrums at both ends of . A detection signal corresponding to the arm angle by the arm angle sensor S2 is taken into the controller 30 .

The bucket angle sensor S3 is attached to the bucket 6, and the angle of rotation of the bucket 6 with respect to the arm 5 (hereinafter referred to as "bucket angle"), for example, the angle of the bucket 6 with respect to a straight line connecting fulcrums at both ends of the arm 5 in a side view. Detects the angle formed by a straight line connecting the fulcrum of the blade and the tip (cutting edge). A detection signal corresponding to the bucket angle by the bucket angle sensor S3 is taken into the controller 30 .

The fuselage tilt sensor S4 detects the tilt state of the fuselage (the upper rotating body 3 or the lower traveling body 1) with respect to the horizontal plane. The machine body tilt sensor S4 is attached to, for example, the upper revolving body 3, and measures the tilt angles of the excavator 100 (that is, the upper revolving body 3) about two axes in the front-rear direction and the left-right direction (hereinafter referred to as "front-rear tilt angle" and "left-right tilt angle"). tilt angle”). The body tilt sensor S4 may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an IMU, and the like. A detection signal corresponding to the tilt angle (front-rear tilt angle and left-right tilt angle) by the body tilt sensor S4 is taken into the controller 30 .

The turning state sensor S<b>5 outputs detection information regarding the turning state of the upper turning body 3 . The turning state sensor S5 detects, for example, the turning angular velocity and turning angle of the upper turning body 3 . The turning state sensor S5 may include, for example, a gyro sensor, resolver, rotary encoder, and the like. A detection signal corresponding to the turning angle and turning angular velocity of the upper turning body 3 by the turning state sensor S5 is taken into the controller 30 .

The imaging device S6 as a space recognition device images the surroundings of the excavator 100 . The imaging device S6 includes a camera S6F for imaging the front of the excavator 100, a camera S6L for imaging the left of the excavator 100, a camera S6R for imaging the right of the excavator 100, and a camera S6B for imaging the rear of the excavator 100. .

The camera S6F is attached to the ceiling of the cabin 10, that is, inside the cabin 10, for example. In addition, the camera S6F may be attached to the outside of the cabin 10, such as the roof of the cabin 10, the side of the boom 4, or the like. The camera S6L is attached to the left end of the upper surface of the upper rotating body 3, the camera S6R is attached to the right end of the upper surface of the upper rotating body 3, and the camera S6B is attached to the rear end of the upper surface of the upper rotating body 3.

The imaging device S6 (cameras S6F, S6B, S6L, S6R) is, for example, a monocular wide-angle camera having a very wide angle of view. Also, the imaging device S6 may be a stereo camera, a distance image camera, or the like. An image captured by the imaging device S6 is captured by the controller 30 via the display device 40 .

The imaging device S6 as a space recognition device may function as an object detection device. In this case, the imaging device S6 may detect objects existing around the excavator 100 . Objects to be sensed may include, for example, people, animals, vehicles, construction machinery, buildings, holes, and the like. Further, the imaging device S6 may calculate the distance to the object recognized from the imaging device S6 or the excavator 100 . The imaging device S6 as an object detection device can include, for example, a stereo camera, a distance image sensor, and the like. The space recognition device is, for example, a monocular camera having an imaging device such as a CCD or CMOS, and outputs captured images to the display device 40 . The space recognition device may also be configured to calculate the distance from the space recognition device or shovel 100 to the recognized object. Further, in addition to the imaging device S6, other object detection devices such as an ultrasonic sensor, a millimeter wave radar, a LIDAR, an infrared sensor, etc. may be provided as the space recognition device. When a millimeter wave radar, an ultrasonic sensor, a laser radar, or the like is used as the space recognition device 80, a large number of signals (laser light, etc.) are transmitted to an object, and the reflected signals are received. Object distance and direction may be detected.

Note that the imaging device S6 may be directly connected to the controller 30 so as to be communicable.

A boom rod pressure sensor S7R and a boom bottom pressure sensor S7B are attached to the boom cylinder 7 . The arm cylinder 8 is attached with an arm rod pressure sensor S8R and an arm bottom pressure sensor S8B. A bucket rod pressure sensor S9R and a bucket bottom pressure sensor S9B are attached to the bucket cylinder 9 . The boom rod pressure sensor S7R, boom bottom pressure sensor S7B, arm rod pressure sensor S8R, arm bottom pressure sensor S8B, bucket rod pressure sensor S9R, and bucket bottom pressure sensor S9B are also collectively referred to as "cylinder pressure sensors."

The boom rod pressure sensor S7R detects the pressure in the rod side oil chamber of the boom cylinder 7 (hereinafter referred to as "boom rod pressure"), and the boom bottom pressure sensor S7B detects the pressure in the bottom side oil chamber of the boom cylinder 7 (hereinafter referred to as "boom rod pressure"). , “boom bottom pressure”). The arm rod pressure sensor S8R detects the pressure in the rod side oil chamber of the arm cylinder 8 (hereinafter referred to as "arm rod pressure"), and the arm bottom pressure sensor S8B detects the pressure in the bottom side oil chamber of the arm cylinder 8 (hereinafter referred to as "arm rod pressure"). , “arm bottom pressure”) is detected. The bucket rod pressure sensor S9R detects the pressure of the rod side oil chamber of the bucket cylinder 9 (hereinafter referred to as "bucket rod pressure"), and the bucket bottom pressure sensor S9B detects the pressure of the bottom side oil chamber of the bucket cylinder 9 (hereinafter referred to as "bucket rod pressure"). , “bucket bottom pressure”) is detected.

The positioning device P1 measures the position and orientation of the upper revolving structure 3 . The positioning device P1 is, for example, a GNSS (Global Navigation Satellite System) compass, detects the position and orientation of the upper swing structure 3, and the detection signal corresponding to the position and orientation of the upper swing structure 3 is captured by the controller 30. . Further, the function of detecting the orientation of the upper revolving body 3 among the functions of the positioning device P1 may be replaced by an orientation sensor attached to the upper revolving body 3 .

The communication device T1 communicates with an external device through a predetermined network including a mobile communication network, a satellite communication network, the Internet network, etc., which terminates in a base station. The communication device T1 includes, for example, a mobile communication module compatible with mobile communication standards such as LTE (Long Term Evolution), 4G (4th Generation), and 5G (5th Generation), and a satellite communication module for connecting to a satellite communication network. modules and the like.

The machine guidance section 50 executes control of the excavator 100 regarding machine guidance functions, for example. The machine guidance unit 50, for example, conveys work information such as the distance between the target work surface and the tip of the attachment, specifically, the work site of the end attachment, to the operator through the display device 40, the voice output device 43, and the like. . Data relating to the target construction surface is stored in advance in the storage device 47, for example, as described above. Data relating to the target construction surface is expressed, for example, 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 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. It is an XYZ coordinate system. The operator may set an arbitrary point on the construction site as a reference point, and set the target construction plane through the input device 42 based on the relative positional relationship with the reference point. The work site of the bucket 6 is, for example, the toe of the bucket 6, the back surface of the bucket 6, and the like. Further, when a breaker, for example, is employed as the end attachment instead of the bucket 6, the tip of the breaker corresponds to the working portion. The machine guidance unit 50 notifies the operator of work information through the display device 40, the audio output device 43, etc., and guides the operator's operation of the excavator 100 through the operation device 26. FIG.

The machine guidance unit 50 also controls the excavator 100 regarding machine control functions, for example. For example, when the operator is manually excavating, the machine guidance unit 50 controls 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 match. may be operated automatically.

The machine guidance unit 50 receives information from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the body tilt sensor S4, the turning state sensor S5, the imaging device S6, the positioning device P1, the communication device T1, the input device 42, and the like. get. Then, for example, the machine guidance unit 50 calculates the distance between the bucket 6 and the target construction surface based on the acquired information, and the bucket The operator is notified of the distance between 6 and the target construction surface, and the tip of the attachment (specifically, the work site such as the toe or back of the bucket 6) matches the target construction surface. Automatically control the movement of attachments. The machine guidance unit 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 angle calculation unit 55 as a detailed functional configuration related to the machine guidance function and the machine control function. , and a relative angle calculator 56 .

The position calculator 51 calculates the position of a predetermined positioning target. For example, the position calculator 51 calculates the coordinate points in the reference coordinate system of the tip of the attachment, more specifically, the working part such as the tip of the bucket 6 or the back surface thereof. Specifically, the position calculator 51 calculates the coordinate point of the work site of the bucket 6 from elevation angles (boom angle, arm angle, and bucket angle) of the boom 4 , arm 5 , and bucket 6 .

The distance calculator 52 calculates the distance between two positioning targets. For example, the distance calculator 52 calculates the distance between the tip of the attachment, more specifically, the working part such as the toe or back of the bucket 6 and the target construction surface. Further, the distance calculation unit 52 may calculate the angle (relative angle) between the back surface of the bucket 6 as the work site and the target construction surface.

The information transmission unit 53 transmits (notifies) various types of information to the operator of the excavator 100 through predetermined notification means such as the display device 40 and the audio output device 43 . The information transmission unit 53 notifies the operator of the excavator 100 of the magnitude (degree) of the various distances calculated by the distance calculation unit 52 . For example, using at least one of visual information from the display device 40 and auditory information from the audio output device 43, the operator is informed of the distance (size) between the tip of the bucket 6 and the target construction surface. In addition, the information transmission unit 53 uses at least one of the visual information from the display device 40 and the auditory information from the audio output device 43 to use (the magnitude of) the relative angle between the back surface of the bucket 6 as the working part and the target construction surface. ) may be communicated to the operator.

Specifically, the information transmission unit 53 uses the intermittent sound produced by the voice output device 43 to inform the operator of the distance (for example, the vertical distance) between the work site of the bucket 6 and the target construction surface. In this case, the information transmission unit 53 may shorten the interval of the intermittent sound as the vertical distance becomes smaller, and lengthen the sense of the intermittent sound as the vertical distance becomes larger. Further, the information transmission unit 53 may use a continuous sound, or may express the difference in vertical distance while changing the pitch, strength, etc. of the sound. In addition, the information transmission unit 53 may issue an alarm through the audio output device 43 when the tip of the bucket 6 is positioned lower than the target construction surface, that is, when it exceeds the target construction surface. The alarm is, for example, a continuous sound significantly louder than the intermittent sound.

In addition, the information transmission unit 53 is used to determine the distance between the tip of the attachment, specifically, the working portion of the bucket 6 and the target construction surface, and the relative angle between the back surface of the bucket 6 and the target construction surface. The size or the like may be displayed on the display device 40 as work information. The display device 40 displays the work information received from the information transmission unit 53 together with the image data received from the imaging device S6 under the control of the controller 30, for example. The information transmission unit 53 may transmit the magnitude of the vertical distance to the operator, for example, using an image of an analog meter, an image of a bar graph indicator, or the like.

The automatic control unit 54 automatically supports the operator's manual operation of the excavator 100 through the operation device 26 by automatically operating the actuator. Specifically, as will be described later, the automatic control unit 54 controls control valves (specifically, The pilot pressure acting on control valve 173, control valves 175L, 175R, and control valve 174) can be individually and automatically adjusted. Thereby, the automatic control unit 54 can automatically operate each hydraulic actuator. Control relating to the machine control function by the automatic control unit 54 may be executed, for example, when a predetermined switch included in the input device 42 is pressed. The predetermined switch is, for example, a machine control switch (hereinafter referred to as "MC (Machine Control) switch"). may be placed at the tip of the The following description is based on the premise that the machine control function is valid when the MC switch is pressed.

For example, when the MC switch or the like is pressed, the automatic control unit 54 automatically activates at least one of the boom cylinder 7 and the bucket cylinder 9 in accordance with the operation of the arm cylinder 8 in order to support excavation work and shaping work. expand and contract. Specifically, when the operator manually closes the arm 5 (hereinafter referred to as "arm closing operation"), the automatic control unit 54 controls the target construction surface and the work site such as the toe or back surface of the bucket 6. At least one of the boom cylinder 7 and the bucket cylinder 9 is automatically extended and contracted so that the position of the boom cylinder 7 and the bucket cylinder 9 match. In this case, the operator can close the arm 5 while aligning the toe of the bucket 6 with the target construction surface, for example, simply by closing the lever device corresponding to the operation of the arm 5 .

Further, when the MC switch or the like is pressed, the automatic control unit 54 may automatically rotate the swing hydraulic motor 2A (an example of an actuator) in order to make the upper swing structure 3 face the target construction surface. . Hereinafter, the control by which the controller 30 (automatic control unit 54) causes the upper rotating body 3 to face the target construction surface will be referred to as "facing control". As a result, the operator or the like simply depresses a predetermined switch, or, with the switch being depressed, operates a lever device 26C, which will be described later, corresponding to a revolving operation. It can face the face. Further, the operator can cause the upper revolving structure 3 to face the target construction surface and start the machine control function related to the above-described excavation work of the target construction surface, etc., simply by pressing the MC switch.

For example, when the upper revolving body 3 of the excavator 100 is facing the target construction surface, the tip of the attachment (for example, the tip of the bucket 6 as a work site, the back surface, etc.) is moved to the target construction surface ( In this state, it is possible to move along the direction of inclination of the upward slope BS). Specifically, when the upper revolving body 3 of the excavator 100 faces the target construction plane, the operation surface of the attachment (attachment operation surface) perpendicular to the revolving plane of the excavator 100 is the target construction surface corresponding to the cylindrical body. It is a state including the normal of the surface (in other words, a state along the normal).

If the attachment operating surface of the excavator 100 does not include the normal line of the target construction surface corresponding to the cylinder, the tip of the attachment cannot move the target construction surface in the direction of inclination. Therefore, as a result, the excavator 100 cannot properly construct the target construction surface. On the other hand, the automatic control unit 54 automatically rotates the hydraulic swing motor 2A so that the upper swing structure 3 faces the front. As a result, the excavator 100 can appropriately construct the target construction surface.

In direct facing control, the automatic control unit 54 controls, for example, the left end vertical distance between the left end coordinate point of the toe of the bucket 6 and the target construction surface (hereinafter simply referred to as the “left end vertical distance”), When the right end vertical distance between the right end coordinate point and the target construction surface (hereinafter simply referred to as "right end vertical distance") is equal, it is determined that the shovel is facing the target construction surface. In addition, the automatic control unit 54 determines whether the difference is equal to or less than a predetermined value, not when the left edge vertical distance and the right edge vertical distance are equal (that is, when the difference between the left edge vertical distance and the right edge vertical distance is zero). , it may be determined that the excavator 100 is facing the target construction surface.

Further, the automatic control unit 54 may operate the turning hydraulic motor 2A in the facing control, for example, based on the difference between the left end vertical distance and the right end vertical distance. Specifically, when a predetermined switch such as an MC switch is depressed and the lever device 26C corresponding to the turning operation is operated, the lever device 26C is moved in the direction in which the upper turning body 3 faces the target construction surface. Determine whether or not it has been operated. For example, when the lever device 26C is operated in a direction that increases the vertical distance between the toe of the bucket 6 and the target construction surface (uphill slope BS), the automatic control unit 54 does not perform facing control. On the other hand, when the turning operation lever is operated in the direction in which the vertical distance between the toe of the bucket 6 and the target construction surface (uphill slope BS) becomes smaller, the automatic control unit 54 performs facing control. As a result, the automatic control unit 54 can operate the turning hydraulic motor 2A so that the difference between the left end vertical distance and the right end vertical distance becomes small. After that, when the difference becomes equal to or less than a predetermined value or becomes zero, the automatic control section 54 stops the turning hydraulic motor 2A. Further, the automatic control unit 54 sets a turning angle at which the difference is a predetermined value or less or zero as a target angle, and the target angle and the current turning angle (specifically, based on the detection signal of the turning state sensor S5). The operation of the turning hydraulic motor 2A may be controlled so that the angle difference from the detected value) becomes zero. In this case, the turning angle is, for example, the angle of the longitudinal axis of the upper turning body 3 with respect to the reference direction.

As described above, when a swing electric motor is mounted on the excavator 100 instead of the swing hydraulic motor 2A, the automatic control unit 54 performs facing control with the swing electric motor (an example of an actuator) as the control target. .

The turning angle calculator 55 calculates the turning angle of the upper turning body 3 . Thereby, the controller 30 can identify the current orientation of the upper swing body 3 . The turning angle calculator 55 calculates the angle of the longitudinal axis of the upper turning body 3 with respect to the reference direction as the turning angle, for example, based on the output signal of the GNSS compass included in the positioning device P1. Further, the turning angle calculator 55 may calculate the turning angle based on the detection signal of the turning state sensor S5. Further, when a reference point is set at the construction site, the turning angle calculator 55 may set the direction of the reference point viewed from the turning axis as the reference direction.

The turning angle indicates the direction in which the attachment operating surface extends with respect to the reference direction. The attachment operating surface is, for example, a virtual plane that traverses the attachment and is arranged so as to be perpendicular to the revolving plane. The pivot plane is, for example, a virtual plane that includes the bottom surface of the pivot frame perpendicular to the pivot axis. The controller 30 (machine guidance section 50) determines that the upper rotating body 3 faces the target construction surface, for example, when it determines that the attachment operating surface includes the normal line of the target construction surface.

The relative angle calculator 56 calculates a turning angle (relative angle) necessary for making the upper turning body 3 face the target construction surface. The relative angle is formed, for example, between the direction of the front-rear axis of the upper revolving body 3 when the upper revolving body 3 faces the target construction surface, and the current direction of the front-rear axis of the upper revolving body 3. It is a relative angle. The relative angle calculator 56 calculates the relative angle based on, for example, the data on the target construction surface stored in the storage device 47 and the turning angle calculated by the turning angle calculator 55 .

When the lever device 26C corresponding to the turning operation is operated in a state where a predetermined switch such as the MC switch is pressed, the automatic control unit 54 is turned in the direction in which the upper turning body 3 faces the target construction surface. determine whether or not When the automatic control unit 54 determines that the upper turning body 3 has been turned in the direction to face the target construction surface, the automatic control unit 54 sets the relative angle calculated by the relative angle calculating unit 56 as the target angle. Then, when the change in the swing angle after the lever device 26C is operated reaches the target angle, the automatic control unit 54 determines that the upper swing structure 3 has faced the target working surface, and the hydraulic swing motor 2A is turned on. You can stop moving. As a result, the automatic control unit 54 can cause the upper rotating body 3 to face the target construction surface on the premise of the configuration shown in FIG. 2 . In the embodiment of direct facing control, an example of direct facing control with respect to the target construction surface was shown, but the present invention is not limited to this. For example, when scooping up temporarily placed earth and sand onto a dump truck, a target excavation trajectory corresponding to the target volume is generated, and the turning operation is controlled so that the attachment faces the target excavation trajectory. may In this case, the target excavation trajectory is changed each time the scooping operation is performed. Therefore, after the earth is discharged to the dump truck, it is controlled to face the newly changed target excavation trajectory.

Also, the swing hydraulic motor 2A has a first port 2A1 and a second port 2A2. The hydraulic sensor 21 detects the pressure of hydraulic fluid in the first port 2A1 of the turning hydraulic motor 2A. The hydraulic sensor 22 detects the pressure of hydraulic fluid in the second port 2A2 of the turning hydraulic motor 2A. Detection signals corresponding to the discharge pressure detected by the hydraulic sensors 21 and 22 are taken into the controller 30 .

Also, the first port 2A1 is connected via a relief valve 23 to a hydraulic oil tank. The relief valve 23 opens when the pressure on the side of the first port 2A1 reaches a predetermined relief pressure, and discharges hydraulic fluid on the side of the first port 2A1 to the hydraulic fluid tank. Similarly, the second port 2A2 is connected via a relief valve 24 to the hydraulic oil tank. The relief valve 24 opens when the pressure on the side of the second port 2A2 reaches a predetermined relief pressure, and discharges hydraulic fluid on the side of the second port 2A2 to the hydraulic fluid tank.

[Excavator hydraulic system]
Next, referring to FIG. 3, the hydraulic system of the excavator 100 according to this embodiment will be described.

FIG. 3 is a diagram schematically showing an example of the configuration of the hydraulic system of the excavator 100 according to this embodiment.

In FIG. 3, the mechanical power system, hydraulic oil line, pilot line, and electrical control system are indicated by double lines, solid lines, broken lines, and dotted lines, respectively, as in FIG. 2 and the like.

The hydraulic system realized by the hydraulic circuit circulates hydraulic oil from main pumps 14L and 14R driven by the engine 11 to hydraulic oil tanks through center bypass oil passages C1L and C1R and parallel oil passages C2L and C2R. Let

The center bypass oil passage C1L starts from the main pump 14L, passes through the control valves 171, 173, 175L, 176L arranged in the control valve 17 in order, and reaches the hydraulic oil tank.

The center bypass oil passage C1R starts from the main pump 14R, passes through the control valves 172, 174, 175R, and 176R arranged in the control valve 17 in order, and reaches the hydraulic oil tank.

The control valve 171 is a spool valve that supplies hydraulic fluid discharged from the main pump 14L to the traveling hydraulic motor 1L and discharges hydraulic fluid discharged from the traveling hydraulic motor 1L to the hydraulic fluid tank.

The control valve 172 is a spool valve that supplies hydraulic fluid discharged from the main pump 14R to the traveling hydraulic motor 1R and discharges hydraulic fluid discharged from the traveling hydraulic motor 1R to the hydraulic fluid tank.

The control valve 173 is a spool valve that supplies hydraulic fluid discharged from the main pump 14L to the swing hydraulic motor 2A and discharges hydraulic fluid discharged from the swing hydraulic motor 2A to a hydraulic fluid tank.

The control valve 174 is a spool valve that supplies the hydraulic fluid discharged from the main pump 14R to the bucket cylinder 9 and discharges the hydraulic fluid in the bucket cylinder 9 to the hydraulic fluid tank.

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

The control valves 176L, 176R supply the hydraulic fluid discharged from the main pumps 14L, 14R to the arm cylinder 8 and discharge the hydraulic fluid in the arm cylinder 8 to the hydraulic fluid tank.

The control valves 171, 172, 173, 174, 175L, 175R, 176L, and 176R respectively adjust the flow rate of the hydraulic oil supplied to and discharged from the hydraulic actuator and control the flow direction according to the pilot pressure acting on the pilot port. to switch.

The parallel oil passage C2L supplies hydraulic oil for the main pump 14L to the control valves 171, 173, 175L, 176L in parallel with the center bypass oil passage C1L. Specifically, the parallel oil passage C2L branches off from the center bypass oil passage C1L on the upstream side of the control valve 171, and supplies hydraulic oil for the main pump 14L in parallel to each of the control valves 171, 173, 175L, and 176R. configured as possible. As a result, the parallel oil passage C2L supplies hydraulic oil to the downstream control valves when the flow of hydraulic oil through the center bypass oil passage C1L is restricted or blocked by any of the control valves 171, 173, 175L. can.

The parallel oil passage C2R supplies hydraulic oil for the main pump 14R to the control valves 172, 174, 175R, 176R in parallel with the center bypass oil passage C1R. Specifically, the parallel oil passage C2R branches off from the center bypass oil passage C1R on the upstream side of the control valve 172, and supplies hydraulic oil for the main pump 14R in parallel to each of the control valves 172, 174, 175R, and 176R. configured as possible. The parallel oil passage C2R can supply hydraulic oil to control valves further downstream when the flow of hydraulic oil through the center bypass oil passage C1R is restricted or blocked by any of the control valves 172, 174, 175R.

The regulators 13L, 13R respectively adjust the discharge amounts of the main pumps 14L, 14R by adjusting the tilt angles of the swash plates of the main pumps 14L, 14R under the control of the controller 30 .

A discharge pressure sensor 28L detects the discharge pressure of the main pump 14L, and a detection signal corresponding to the detected discharge pressure is taken into the controller 30. FIG. The same applies to the discharge pressure sensor 28R. Thereby, the controller 30 can control the regulators 13L and 13R according to the discharge pressures of the main pumps 14L and 14R.

Negative control throttles (hereinafter referred to as "negative control throttles") 18L, 18R are provided between the control valves 176L, 176R, which are the most downstream, respectively, in the center bypass oil passages C1L, C1R and the hydraulic oil tank. As a result, the flow of hydraulic oil discharged by the main pumps 14L, 14R is restricted by the negative control throttles 18L, 18R. The negative control throttles 18L and 18R generate a control pressure (hereinafter referred to as "negative control pressure") for controlling the regulators 13L and 13R.

The negative control pressure sensors 19L and 19R detect the negative control pressure, and a detection signal corresponding to the detected negative control pressure is received by the controller 30. FIG.

The controller 30 may control the regulators 13L, 13R according to the discharge pressures of the main pumps 14L, 14R detected by the discharge pressure sensors 28L, 28R to adjust the discharge amounts of the main pumps 14L, 14R. For example, the controller 30 may control the regulator 13L and adjust the tilt angle of the swash plate of the main pump 14L according to an increase in the discharge pressure of the main pump 14L, thereby reducing the discharge amount. The same applies to the regulator 13R. Thereby, the controller 30 performs total horsepower control of the main pumps 14L, 14R so that the absorption horsepower of the main pumps 14L, 14R represented by the product of the discharge pressure and the discharge amount does not exceed the output horsepower of the engine 11. be able to.

Further, the controller 30 may adjust the discharge amounts of the main pumps 14L, 14R by controlling the regulators 13L, 13R according to the negative control pressures detected by the negative control pressure sensors 19L, 19R. For example, the controller 30 reduces the discharge amounts of the main pumps 14L and 14R as the negative control pressure increases, and increases the discharge amounts of the main pumps 14L and 14R as the negative control pressure decreases.

Specifically, in the standby state (the state shown in FIG. 3) in which none of the hydraulic actuators in the excavator 100 is operated, hydraulic oil discharged from the main pumps 14L and 14R flows through the center bypass oil passages C1L and C1R. It passes through and reaches the negative control diaphragms 18L and 18R. The flow of hydraulic oil discharged from the main pumps 14L, 14R increases the negative control pressure generated upstream of the negative control throttles 18L, 18R. As a result, the controller 30 reduces the discharge amount of the main pumps 14L, 14R to the allowable minimum discharge amount, thereby suppressing the pressure loss (pumping loss) when the discharged hydraulic oil passes through the center bypass oil passages C1L, C1R. .

On the other hand, when one of the hydraulic actuators is operated through the operating device 26, hydraulic fluid discharged from the main pumps 14L and 14R is directed to the operated hydraulic actuator through the control valve corresponding to the operated hydraulic actuator. flow in. The flow of the hydraulic oil discharged from the main pumps 14L, 14R reduces or eliminates the amount reaching the negative control throttles 18L, 18R, thereby reducing the negative control pressure generated upstream of the negative control throttles 18L, 18R. As a result, the controller 30 can increase the discharge amounts of the main pumps 14L and 14R, circulate sufficient working oil to the hydraulic actuator to be operated, and reliably drive the hydraulic actuator to be operated.

[Details of the configuration of the machine control function of the excavator]
Next, with reference to FIG. 4, the details of the configuration regarding the machine control function of the excavator 100 will be described.

FIG. 4 is a diagram schematically showing an example of a component related to the operating system of the hydraulic system of the excavator 100 according to this embodiment. Specifically, FIG. 4A is a diagram showing an example of a pilot circuit that applies pilot pressure to the control valves 175L and 175R that hydraulically control the boom cylinder 7. As shown in FIG. 4B is a diagram showing an example of a pilot circuit that applies pilot pressure to the control valve 174 that hydraulically controls the bucket cylinder 9. As shown in FIG. FIG. 4C is a diagram showing an example of a pilot circuit that applies pilot pressure to the control valve 173 that hydraulically controls the swing hydraulic motor 2A.

Further, for example, as shown in FIG. 4A, the lever device 26A is used by an operator or the like to operate the boom cylinder 7 corresponding to the boom 4. As shown in FIG. 26 A of lever apparatuses output the pilot pressure according to the operation content to the secondary side using the hydraulic fluid discharged from the pilot pump 15. As shown in FIG.

The shuttle valve 32AL has two inlet ports each connected to a pilot line on the secondary side of the lever device 26A corresponding to operation in the raising direction of the boom 4 (hereinafter referred to as "boom raising operation") and a secondary side of the proportional valve 31AL. The outlet port is connected to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R.

The shuttle valve 32AR has two inlet ports each connected to a pilot line on the secondary side of the lever device 26A corresponding to operation in the lowering direction of the boom 4 (hereinafter referred to as "boom lowering operation") and a secondary port of the proportional valve 31AR. The outlet port is connected to the right pilot port of the control valve 175R.

That is, the lever device 26A applies pilot pressure corresponding to the operation content (for example, operation direction and operation amount) to the pilot ports of the control valves 175L and 175R via the shuttle valves 32AL and 32AR. Specifically, when the boom is operated to raise the boom, the lever device 26A outputs a pilot pressure corresponding to the amount of operation to one inlet port of the shuttle valve 32AL, and outputs the pilot pressure to the right side of the control valve 175L via the shuttle valve 32AL. and the left pilot port of the control valve 175R. In addition, when the boom is lowered, the lever device 26A outputs a pilot pressure corresponding to the amount of operation to one inlet port of the shuttle valve 32AR. to act on

The proportional valve 31AL operates according to the control current input from the controller 30. Specifically, the proportional valve 31AL uses hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other inlet port of the shuttle valve 32AL. Thereby, the proportional valve 31AL can adjust the pilot pressure acting on the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the shuttle valve 32AL.

The proportional valve 31AR operates according to the control current input from the controller 30. As shown in FIG. Specifically, the proportional valve 31AR uses hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other inlet port of the shuttle valve 32AR. This allows the proportional valve 31AR to adjust the pilot pressure acting on the right pilot port of the control valve 175R via the shuttle valve 32AR.

That is, the proportional valves 31AL and 31AR can adjust the pilot pressure output to the secondary side so that the control valves 175L and 175R can be stopped at any valve position regardless of the operating state of the lever device 26A.

The proportional valve 33AL, like the proportional valve 31AL, functions as a control valve for machine control. The proportional valve 33AL is arranged in a pipeline that connects the operating device 26 and the shuttle valve 32AL, and is configured to change the flow area of the pipeline. In this embodiment, the proportional valve 33AL operates according to the control command output by the controller 30. FIG. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 reduces the pressure of the hydraulic oil discharged by the operating device 26, and then, via the shuttle valve 32AL, the corresponding control valve in the control valve 17. can be supplied to the pilot port of

Similarly, the proportional valve 33AR functions as a control valve for machine control. The proportional valve 33AR is arranged in a pipeline that connects the operating device 26 and the shuttle valve 32AR, and is configured to change the flow area of the pipeline. In this embodiment, the proportional valve 33AR operates according to a control command output by the controller 30. FIG. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 reduces the pressure of the hydraulic oil discharged by the operating device 26, and then, via the shuttle valve 32AR, the corresponding control valve in the control valve 17. can be supplied to the pilot port of

The operation pressure sensor 29A detects the operation content of the lever device 26A by the operator in the form of pressure (operation pressure), and a detection signal corresponding to the detected pressure is taken into the controller 30. FIG. Thereby, the controller 30 can grasp the operation content with respect to 26 A of lever apparatuses.

Regardless of the operator's operation to raise the lever device 26A, the controller 30 directs hydraulic fluid discharged from the pilot pump 15 through the proportional valve 31AL and the shuttle valve 32AL to the right pilot port and the control port of the control valve 175L. It can be fed to the left pilot port of valve 175R. In addition, the controller 30 directs the hydraulic oil discharged from the pilot pump 15 to the pilot port on the right side of the control valve 175R via the proportional valve 31AR and the shuttle valve 32AR, regardless of the boom lowering operation of the lever device 26A by the operator. can be supplied to That is, the controller 30 can automatically control the operation of raising and lowering the boom 4 . Further, even when a specific operating device 26 is being operated, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to the specific operating device 26 .

The proportional valve 33AL operates according to a control command (current command) output by the controller 30 . Then, the pilot pressure of hydraulic oil introduced from 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 lever device 26A, the proportional valve 33AL, and the shuttle valve 32AL is reduced. The proportional valve 33AR operates according to a control command (current command) output by the controller 30. Then, the pilot pressure of hydraulic fluid introduced from the pilot pump 15 to the right pilot port of the control valve 175R via the lever device 26A, the proportional valve 33AR, and the shuttle valve 32AR is reduced. The proportional valves 33AL, 33AR can adjust the pilot pressure so that the control valves 175L, 175R can be stopped at any valve position.

With this configuration, even when the operator is raising the boom, the controller 30 can operate the raising side pilot port of the control valve 175 (the left side pilot port of the control valve 175L and the control valve 175R right pilot port) to forcibly stop the boom 4 closing operation. The same applies to the case where the lowering operation of the boom 4 is forcibly stopped while the boom lowering operation is being performed by the operator.

Alternatively, the controller 30 may optionally control the proportional valve 31AR to oppose the raise side pilot port of the control valve 175, even when the operator is raising the boom. By increasing the pilot pressure acting on the lower pilot port of the control valve 175 (the right pilot port of the control valve 175R) and forcibly returning the control valve 175 to the neutral position, the boom 4 is forcibly raised. You can stop it. In this case, the proportional valve 33AL may be omitted. The same applies to the case where the lowering operation of the boom 4 is forcibly stopped when the boom lowering operation is being performed by the operator.

As shown in FIG. 4B, the lever device 26B is used by an operator or the like to operate the bucket cylinder 9 corresponding to the bucket 6 . The lever device 26B uses hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure to the secondary side in accordance with the details of its operation.

The shuttle valve 32BL has two inlet ports each connected to a pilot line on the secondary side of the lever device 26B corresponding to the operation of the bucket 6 in the closing direction (hereinafter referred to as "bucket closing operation") and a secondary port of the proportional valve 31BL. , and the outlet port is connected to the left pilot port of control valve 174 .

The shuttle valve 32BR has two inlet ports each connected to a pilot line on the secondary side of the lever device 26B corresponding to the operation in the opening direction of the bucket 6 (hereinafter referred to as "bucket opening operation") and a secondary port of the proportional valve 31BR. , and the outlet port is connected to the right pilot port of control valve 174 .

That is, the lever device 26B causes the pilot pressure corresponding to the operation content to act on the pilot port of the control valve 174 via the shuttle valves 32BL and 32BR. Specifically, when the bucket is closed, the lever device 26B outputs a pilot pressure corresponding to the operation amount to one inlet port of the shuttle valve 32BL, and outputs the pilot pressure to the left side of the control valve 174 via the shuttle valve 32BL. acting on the pilot port of Further, when the bucket is operated to open, the lever device 26B outputs a pilot pressure corresponding to the amount of operation to one inlet port of the shuttle valve 32BR, and the right pilot port of the control valve 174 is output via the shuttle valve 32BR. to act on

The proportional valve 31BL operates according to the control current input from the controller 30. As shown in FIG. Specifically, the proportional valve 31BL uses hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32BL. This allows the proportional valve 31BL to adjust the pilot pressure acting on the left pilot port of the control valve 174 via the shuttle valve 32BL.

The proportional valve 31BR operates according to the control current that the controller 30 outputs. Specifically, the proportional valve 31BR uses hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32BR. This allows the proportional valve 31BR to adjust the pilot pressure acting on the right pilot port of the control valve 174 via the shuttle valve 32BR.

That is, the proportional valves 31BL and 31BR can adjust the pilot pressure output to the secondary side so that the control valve 174 can be stopped at any valve position regardless of the operating state of the lever device 26B.

The proportional valve 33BL, like the proportional valve 31BL, functions as a control valve for machine control. The proportional valve 33BL is arranged in a pipeline that connects the operating device 26 and the shuttle valve 32BL, and is configured to change the flow area of the pipeline. In this embodiment, the proportional valve 33BL operates according to a control command output by the controller 30. FIG. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 reduces the pressure of the hydraulic oil discharged by the operating device 26, and then, via the shuttle valve 32BL, the corresponding control valve in the control valve 17. can be supplied to the pilot port of

Similarly, the proportional valve 33BR functions as a control valve for machine control. The proportional valve 33BR is arranged in a pipeline that connects the operating device 26 and the shuttle valve 32BR, and is configured to change the flow area of the pipeline. In this embodiment, the proportional valve 33BR operates according to a control command output by the controller 30. FIG. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 reduces the pressure of the hydraulic oil discharged by the operating device 26, and then, via the shuttle valve 32BR, the corresponding control valve in the control valve 17. can be supplied to the pilot port of

The operation pressure sensor 29B detects the operation content of the lever device 26B by the operator in the form of pressure (operation pressure), and a detection signal corresponding to the detected pressure is taken into the controller 30. FIG. Thereby, the controller 30 can grasp the operation content of the lever device 26B.

The controller 30 supplies the hydraulic oil discharged 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, regardless of the bucket closing operation of the lever device 26B by the operator. can be made In addition, the controller 30 directs the hydraulic oil discharged from the pilot pump 15 to the pilot port on the right side of the control valve 174 via the proportional valve 31BR and the shuttle valve 32BR, regardless of the bucket opening operation of the lever device 26B by the operator. can be supplied to That is, the controller 30 can automatically control the opening/closing operation of the bucket 6 . Further, even when a specific operating device 26 is being operated, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to the specific operating device 26 .

The operation of the proportional valves 33BL and 33BR for forcibly stopping the operation of the bucket 6 when the bucket closing operation or bucket opening operation is performed by the operator is performed by the boom raising operation or the boom lowering operation by the operator. The operation of the proportional valves 33AL and 33AR for forcibly stopping the operation of the boom 4 is the same as that of the operation of the proportional valves 33AL and 33AR, and redundant description will be omitted.

Further, for example, as shown in FIG. 4C, the lever device 26C is used by an operator or the like to operate the swing hydraulic motor 2A corresponding to the upper swing body 3 (swing mechanism 2). 26 C of lever apparatuses output the pilot pressure according to the operation content to the secondary side using the hydraulic fluid discharged from the pilot pump 15. FIG.

The two inlet ports of the shuttle valve 32CL are the pilot line on the secondary side of the lever device 26C and the proportional valve 31CL. , and the outlet port is connected to the left pilot port of the control valve 173 .

The shuttle valve 32CR has two inlet ports each corresponding to a rightward swinging operation of the upper swing body 3 (hereinafter referred to as a "rightward swinging operation"), a pilot line on the secondary side of the lever device 26C, and a proportional valve. It is connected to the pilot line on the secondary side of 31CR, and the outlet port is connected to the right pilot port of the control valve 173 .

That is, the lever device 26C applies pilot pressure to the pilot port of the control valve 173 through the shuttle valves 32CL and 32CR in accordance with the content of operation in the left-right direction. Specifically, when the lever device 26C is turned to the left, it outputs a pilot pressure corresponding to the amount of operation to one inlet port of the shuttle valve 32CL, and outputs the pilot pressure to the left side of the control valve 173 via the shuttle valve 32CL. acting on the pilot port of Further, when the lever device 26C is operated to turn to the right, the pilot pressure corresponding to the operation amount is output to one inlet port of the shuttle valve 32CR, and the pilot pressure on the right side of the control valve 173 is output via the shuttle valve 32CR. Act on the port.

The proportional valve 31CL operates according to the control current input from the controller 30 . Specifically, the proportional valve 31CL uses hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32CL. This allows the proportional valve 31CL to adjust the pilot pressure acting on the left pilot port of the control valve 173 via the shuttle valve 32CL.

The proportional valve 31CR operates according to the control current that the controller 30 outputs. Specifically, the proportional valve 31CR uses hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32CR. This allows the proportional valve 31CR to adjust the pilot pressure acting on the right pilot port of the control valve 173 via the shuttle valve 32CR.

That is, the proportional valves 31CL and 31CR can adjust the pilot pressure output to the secondary side so that the control valve 173 can be stopped at any valve position regardless of the operating state of the lever device 26C.

The proportional valve 33CL, like the proportional valve 31CL, functions as a control valve for machine control. The proportional valve 33CL is arranged in a pipeline that connects the operating device 26 and the shuttle valve 32CL, and is configured to change the flow area of the pipeline. In this embodiment, the proportional valve 33CL operates according to a control command output by the controller 30. FIG. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 reduces the pressure of the hydraulic oil discharged by the operating device 26, and then, via the shuttle valve 32CL, the corresponding control valve in the control valve 17. can be supplied to the pilot port of

Similarly, the proportional valve 33CR functions as a control valve for machine control. The proportional valve 33CR is arranged in a pipeline that connects the operating device 26 and the shuttle valve 32CR, and is configured to change the flow area of the pipeline. In this embodiment, the proportional valve 33CR operates according to a control command output by the controller 30. FIG. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 reduces the pressure of the hydraulic oil discharged by the operating device 26, and then, via the shuttle valve 32CR, the corresponding control valve in the control valve 17. can be supplied to the pilot port of

The operation pressure sensor 29</b>C detects the operating state of the lever device 26</b>C by the operator as pressure, and a detection signal corresponding to the detected pressure is taken into the controller 30 . Thereby, the controller 30 can grasp the operation content in the left-right direction with respect to the lever apparatus 26C.

The controller 30 supplies the hydraulic fluid 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 of the lever device 26C by the operator. can be made In addition, the controller 30 directs the hydraulic oil discharged from the pilot pump 15 to the pilot on the right side of the control valve 173 via the proportional valve 31CR and the shuttle valve 32CR, regardless of the right turning operation of the lever device 26C by the operator. can be supplied to the port. That is, the controller 30 can automatically control the turning motion of the upper turning body 3 in the horizontal direction. Further, even when a specific operating device 26 is being operated, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to the specific operating device 26 .

The operation of the proportional valves 33CL and 33CR for forcibly stopping the operation of the upper swing body 3 when the operator is performing a swinging operation is performed by the operator's boom raising operation or boom lowering operation. This operation is the same as the operation of the proportional valves 33AL and 33AR for forcibly stopping the operation of the boom 4 when the operation of the boom 4 is stopped, and redundant description will be omitted.

The excavator 100 may further include a configuration for automatically opening and closing the arm 5 and a configuration for automatically moving the undercarriage 1 forward and backward. In this case, in the hydraulic system, the components related to the operation system of the arm cylinder 8, the components related to the operation system of the travel hydraulic motor 1L, and the components related to the operation of the travel hydraulic motor 1R are the components related to the operation system of the boom cylinder 7. It may be configured in the same manner as the parts (FIGS. 4A to 4C).

[Details of configuration related to excavator sediment load detection function]
Next, with reference to FIG. 5, the details of the configuration of the earth and sand load detection function of the excavator 100 according to the present embodiment will be described. FIG. 5 is a diagram schematically showing an example of a component related to the sediment load detection function of the excavator 100 according to this embodiment.

As described above with reference to FIG. 3 , the controller 30 includes the earth and sand load processing section 60 as a functional section related to the function of detecting the earth and sand load excavated by the bucket 6 .

The sediment load processing unit 60 has a load weight calculation unit 61 , a maximum load amount detection unit 62 , an additional load amount calculation unit 63 , a remaining load amount calculation unit 64 , and a load center of gravity calculation unit 65 .

Here, an example of operation of loading earth and sand (load) to a dump truck by the excavator 100 according to the present embodiment will be described.

First, the excavator 100 excavates earth and sand with the bucket 6 by controlling the attachment at the excavation position (excavation operation). Next, the excavator 100 swings the upper swing body 3 to move the bucket 6 from the excavation position to the dumping position (swing operation). A loading platform of a dump truck is arranged below the dumping position. Next, at the dumping position, the excavator 100 controls the attachment to dump the earth and sand in the bucket 6, thereby loading the earth and sand in the bucket 6 onto the bed of the dump truck (earth dumping operation). Next, the excavator 100 swings the upper swing body 3 to move the bucket 6 from the dumping position to the excavating position (swing operation). By repeating these operations, the excavator 100 loads the excavated earth and sand onto the bed of the dump truck.

The load weight calculator 61 calculates the weight of the earth and sand (load) in the bucket 6 . A method of calculating the weight of earth and sand will be described later.

The maximum loading amount detection unit 62 detects the maximum loading amount of the dump truck to be loaded with earth and sand. For example, the maximum loading amount detection unit 62 identifies the dump truck to be loaded with earth and sand based on the image captured by the imaging device S6. Next, the maximum loading amount detection unit 62 detects the maximum loading amount of the dump truck based on the specified image of the dump truck. For example, the maximum loading amount detection unit 62 determines the type of dump truck (size, etc.) based on the specified image of the dump truck. The maximum loading amount detection unit 62 has a table that associates the vehicle type with the maximum loading amount, and obtains the maximum loading amount of the dump truck based on the vehicle type and the table determined from the image. The maximum load capacity, vehicle type, etc. of the dump truck may be input by the input device 42 , and the maximum load capacity detector 62 may obtain the maximum load capacity of the dump truck based on the input information of the input device 42 .

The additional loading amount calculation unit 63 calculates the weight of earth and sand loaded on the dump truck. That is, each time the earth and sand in the bucket 6 are dumped onto the loading platform of the dump truck, the added load amount calculation unit 63 adds the earth and sand weight in the bucket 6 calculated by the load weight calculation unit 61, An additional loading amount (total weight), which is the total weight of earth and sand loaded on the truck bed, is calculated. Note that when the dump truck to be loaded with earth and sand becomes a new dump truck, the added load amount is reset.

The remaining load amount calculation unit 64 calculates the difference between the maximum load amount of the dump truck detected by the maximum load amount detection unit 62 and the current addition load amount calculated by the addition load amount calculation unit 63 as the remaining load amount. The remaining load capacity is the remaining weight of earth and sand that can be loaded on the dump truck.

The load center of gravity calculator 65 calculates the center of gravity of the earth and sand (load) in the bucket 6 . A method of calculating the center of gravity of earth and sand will be described later.

The display device 40 displays the weight of earth and sand in the bucket 6 calculated by the load weight calculator 61, the maximum load of the dump truck detected by the maximum load detector 62, and the load calculated by the additional load calculator 63. The additional load of the dump truck (total weight of earth and sand loaded on the platform) and the remaining load of the dump truck calculated by the remaining load calculating unit 64 (remaining weight of loadable earth and sand) may be displayed. .

It should be noted that the display device 40 may be configured to issue a warning when the additional load capacity exceeds the maximum load capacity. Further, when the calculated earth and sand weight in the bucket 6 exceeds the remaining load capacity, the display device 40 may be configured to display a warning. Note that the warning is not limited to being displayed on the display device 40 , and may be output as an audio output by the audio output device 43 . As a result, it is possible to prevent the earth and sand from being loaded in excess of the maximum load capacity of the dump truck.

[Earth weight calculation method]
Next, a method of calculating the weight of earth and sand (loaded material) in the bucket 6 in the loaded material weight calculator 61 of the excavator 100 according to the present embodiment will be described with reference to FIG. 5 and FIG.

FIG. 6 is a partially enlarged view for explaining the relationship of forces acting on the bucket 6. As shown in FIG. Also, FIG. 6A shows a case where the shape of the earth and sand in the bucket 6 is the first shape (reference shape). FIG. 6B shows a case where the shape of the earth and sand in the bucket 6 is the second shape (an example of the shape when measuring the weight of the earth and sand).

As shown in FIG. 6A, the rear end side of the bucket cylinder 9 is connected to the vicinity of the rear end of the arm 5 by a connecting pin 9a. The tip side of the bucket cylinder 9 is connected to one ends of two links 91 and 92 by a connecting pin 9b. One end of the link 91 is connected to the tip of the bucket cylinder 9 by a connecting pin 9b, and the other end is connected to the vicinity of the tip of the arm 5 by a connecting pin 9c. One end of the link 92 is connected to the tip of the bucket cylinder 9 by a connecting pin 9b, and the other end is connected to the vicinity of the base end of the bucket 6 by a connecting pin 9d.

Also, as shown in FIG. 6A, L1 is the horizontal distance between the center of gravity Ge of the bucket 6 and the center of the connecting pin 6b. L2 is the horizontal distance between the center of gravity Gl of the earth and sand L in the bucket 6 and the center of the connecting pin 6b. L3 is the distance between a line segment (the central axis of the bucket cylinder 9) passing through the center of the connecting pin 9a and the center of the connecting pin 9b and the center of the connecting pin 9c. L4 is the distance between the line segment (the central axis of the link 92) passing through the center of the connecting pin 9b and the center of the connecting pin 9d and the center of the connecting pin 9c. L5 is the distance between the line segment (the central axis of the link 92) passing through the center of the connecting pin 9b and the center of the connecting pin 9d and the center of the bucket support shaft 6b.

When the bucket 6 of the shovel 100 is maintained in a predetermined load holding posture regardless of the tilt angle of the arm 5, for example, in a predetermined horizontal posture in which the bucket tip 6a is at the same height as the bucket support shaft 6b, the bucket support A moment M due to the weight of the bucket 6 side and a moment due to the reaction force F of the bucket cylinder 9 that maintains the bucket 6 in the cargo holding posture act around the shaft 6b. Since the bucket 6 is balanced in this state, both moments are opposite in direction and equal in magnitude due to the balance condition.

The moment M due to the weight of the bucket 6 can be divided into the moment Me due to the weight We of the bucket 6 and the moment Ml due to the weight Wl of the soil L, and can be expressed by the following equation (1).

M=Me+Ml (1)

Next, the moment due to the reaction force F of the bucket cylinder 9 that maintains the bucket 6 in the load holding posture will be described. First, assuming that the moment mc is given by the reaction force F of the bucket cylinder 9 about the center of the connecting pin 9c of the link 91, it can be expressed by the following equation (2-1).

mc=F L3 (2-1)

On the other hand, the link 91 and the link 92 are rotatably connected at the center of the connecting pin 9b. It can be expressed by the following equation (2-2) from the balance with the moment mc.

fbd L4=mc (2-2)

Furthermore, around the center of the bucket support shaft 6b, since the reaction force fcd acting on the center of the connecting pin 9d and the moment M of the bucket 6 are balanced, the equation (2-3) below can be used.

fcd·L5=M (2-3)

By rearranging the equations (2-1) to (2-3), the balance equation can be represented by the following equation (2).

F・L3・L5/L4=M (2)

Here, when the bucket 6 is kept in a predetermined load holding posture, the positions of the connecting pins 9a to 9d with respect to the position of the bucket support shaft 6b are detected by posture sensors (for example, boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, body tilt sensor S4, turning state sensor S5) can be uniquely obtained, and distances L3, L4, and L5 can be obtained.

Further, when P is the load pressure detected based on the pressure sensor of the bucket cylinder 9 (for example, bucket rod pressure sensor S9R, bucket bottom pressure sensor S9) and S is the pressure receiving area of the piston of the bucket cylinder 9, the bucket cylinder 9 can be expressed by the following equation (3).

F=P×S (3)

As described above, the moment due to the reaction force F of the bucket cylinder 9 can be obtained from the equations (2) and (3) based on the detected values of the attitude sensor and the pressure sensor of the bucket cylinder 9 .

On the other hand, the moment Me due to the dead weight We of the bucket 6 can be expressed by the following equation (4). Also, the moment Ml due to the weight Wl of the earth and sand L can be expressed by the following equation (5).

Me=We×L1 (4)
Ml=Wl×L2 (5)

In addition, when the bucket 6 is kept in a predetermined load holding posture, the distance L1 can be obtained by the posture sensor. Note that the distance L2 is obtained in advance experimentally and stored in the controller 30, for example. Alternatively, the distance L2 may be obtained based on the center of gravity of the earth and sand calculated by the load center-of-gravity calculator 65, which will be described later.

As described above, based on the detected values of the attitude sensor and the pressure sensor of the bucket cylinder 9, the weight Wl of the earth and sand L can be obtained from equations (1) to (5). Although the case where the earth and sand weight is obtained based on the pressure of the bucket cylinder 9 has been described as an example, the present invention is not limited to this. For example, the weight Wl of the soil L may be obtained based on the detected values of the attitude sensor and the pressure sensor of the boom cylinder 7 . Further, the weight Wl of the earth and sand L may be obtained based on the detected values of the attitude sensor and the pressure sensor of the arm cylinder 8 . Note that the relational expressions in these cases can be obtained in the same manner, and the description thereof is omitted.

Here, during the excavation operation of the excavator 100, earth and sand enter the bucket 6 from the tip 6a of the bucket. Depending on the skill of the operator, the shape of the earth and sand L in the bucket 6 is not limited to the case where the earth and sand L are evenly loaded inside the bucket 6 like the standard shape shown in FIG. 6(A). For example, as shown in FIG. 6B, the shape of the earth and sand La in the bucket 6 may be biased toward the tip 6a of the bucket and differ from the reference shape. In this case, the position of the center of gravity Gla of the earth and sand La in the bucket 6 may differ from the position of the center of gravity Gl of the earth and sand L of the reference shape shown in FIG. 6(A).

Returning to FIG. 5 , the load center-of-gravity calculator 65 has a function of calculating the position of the center of gravity of the earth and sand loaded on the bucket 6 . The load center-of-gravity calculator 65 calculates the position of the center-of-gravity of the earth and sand, for example, using any one of the first to fourth center-of-gravity calculation methods.

(First gravity center calculation method)
A first method of calculating the center of gravity by the load center of gravity calculator 65 will be described. The imaging device S6 images the shape of the earth and sand loaded on the bucket 6 . The load center-of-gravity calculator 65 acquires an image captured by the imaging device S6. The load center-of-gravity calculator 65 calculates the position of the center of gravity of the earth and sand based on the shape of the earth and sand imaged by the imaging device S6.

Here, the load center-of-gravity calculator 65 has shape information of the inner surface of the bucket 6 . The load center-of-gravity calculator 65 estimates the overall shape of the earth and sand loaded on the bucket 6 based on the shape of the earth and sand imaged by the imaging device S6 and the shape information of the inner surface of the bucket 6 . The load center-of-gravity calculator 65 calculates the position of the center of gravity of the earth and sand based on the estimated overall shape of the earth and sand. For example, the load center-of-gravity calculator 65 calculates the position of the center of gravity of the earth and sand based on the estimated overall shape of the earth and sand, assuming that the density distribution of the earth and sand is uniform.

As the imaging device S6 that captures the shape of the earth and sand loaded on the bucket 6, for example, a camera S6F that captures the front of the excavator 100 may be used. Also, a camera (not shown) for imaging the shape of earth and sand may be provided on the boom 4 or the arm 5 . By providing an imaging device on the boom 4 or the arm 5, it is possible to image the earth and sand from above, so that the shape of the earth and sand can be estimated more accurately. These cameras may also be, for example, stereo cameras.

(Second gravity center calculation method)
A second center-of-gravity calculation method by the load center-of-gravity calculator 65 will be described. The operator operates the input device 42 to select parameters before starting excavation operation of the excavator 100 . As parameters, for example, the type of earth and sand to be excavated (for example, soil, sand, gravel, etc.) and the condition of the earth and sand (for example, wet state, dry state, etc.) are input. The load center-of-gravity calculator 65 calculates the position of the center of gravity of the earth and sand based on at least one of the input type and state of the earth and sand.

Here, the angle of repose differs depending on the type and state of earth and sand. Therefore, when the bucket 6 is used to excavate the earth and sand, and the attitude of the bucket 6 is set to the attitude for estimating the weight of the earth and sand (load holding attitude), the shape of the upper surface of the earth and sand loaded on the bucket 6 is estimated according to the type and condition of the earth and sand. can do. The load center of gravity calculation unit 65 estimates the overall shape of the earth and sand loaded on the bucket 6 based on the estimated shape of the upper surface of the earth and sand and shape information of the inner surface of the bucket 6 . Further, the load center-of-gravity calculator 65 calculates the position of the center of gravity of the earth and sand based on the estimated overall shape of the earth and sand.

Note that a table in which the parameters (type, state) of the earth and sand are associated with the position of the center of gravity of the earth and sand loaded in the bucket 6 may be stored in the load center-of-gravity calculation unit 65 . In this case, the load center-of-gravity calculator 65 can calculate the position of the center of gravity of the earth and sand based on the input parameters and the table. Note that the table may be obtained through experiments, simulations, or the like.

(Third gravity center calculation method)
A third center-of-gravity calculation method by the load center-of-gravity calculator 65 will be described with reference to FIG. FIG. 7 is a schematic diagram for explaining the third gravity center calculation method by the load center-of-gravity calculator 65. As shown in FIG.

Based on the cylinder pressure of the bucket cylinder 9 when the bucket 6 is in the first state and the cylinder pressure of the bucket cylinder 9 when the bucket 6 is in the second state, the load center of gravity calculation unit 65 calculates the weight of the earth and sand. Calculate the position of the center of gravity.

First, the controller 30 puts the bucket 6 in the first state (indicated by solid lines in FIG. 7). In the example shown in FIG. 7, the posture is such that the opening surface of the bucket 6 is horizontal. Let Ge1 be the center of gravity of the bucket 6 in the first state, and Gl1 be the center of gravity of the earth and sand in the first state. Let L be the horizontal distance from the bucket support shaft 6b to the center of gravity Ge1, and L+ΔL be the horizontal distance from the bucket support shaft 6b to the center of gravity Gl1. Also, let W be the weight of the earth and sand.

In the first state, the torque τ1 due to the weight of the earth and sand on the bucket support shaft 6b can be expressed by the following equation (6).

τ1=W(L+ΔL) (6)

Next, the controller 30 puts the bucket 6 in the second state (indicated by a two-dot chain line in FIG. 7). In the example shown in FIG. 7, the attitude is such that the bucket angle is opened by θ from the first state. Let Ge2 be the center of gravity of the bucket 6 in the second state, and Gl2 be the center of gravity of the earth and sand in the second state. In this case, the horizontal distance from the bucket support shaft 6b to the center of gravity Ge2 is Lsin θ, and the horizontal distance from the bucket support shaft 6b to the center of gravity Gl2 is Lsin θ+ΔLsin θ.

In the second state, the torque τ2 due to the weight of the earth and sand on the bucket support shaft 6b can be expressed by the following equation (7).

τ2=W(L sin θ+ΔL sin θ) (7)

In equations (6) and (7), the soil weight W is the same, so the following equation (8) is derived.

τ1/(L+ΔL)=τ2/(L sin θ+ΔL sin θ) (8)

Here, the torque τ1 and the torque τ2 can be obtained from the cylinder pressure of the bucket cylinder 9 (bucket rod pressure sensor S9R, bucket bottom pressure sensor S9B) and the attitude sensor (bucket angle sensor S3). Also, the angle θ can be determined by the bucket angle sensor S3. Further, the center of gravity Ge2 of the bucket 6 is obtained in advance, and the distance L is also a known value. The load center-of-gravity calculator 65 can calculate the position of the center of gravity of the earth and sand based on these values and equation (8).

(Fourth center-of-gravity calculation method)
A fourth center-of-gravity calculation method by the load center-of-gravity calculator 65 will be described with reference to FIG. FIG. 8 is a schematic diagram for explaining a fourth center-of-gravity calculation method by the load center-of-gravity calculator 65. As shown in FIG.

The load center of gravity calculator 65 calculates the position of the center of gravity of the earth and sand based on at least two of the pressure of the boom cylinder 7 , the pressure of the arm cylinder 8 and the pressure of the bucket cylinder 9 .

First, the controller 30 puts the attachment in a predetermined state. In the example shown in FIG. 8, the posture is such that the opening surface of the bucket 6 is horizontal. Here, the center of gravity of the earth and sand L of the reference shape is assumed to be Gl, and the center of gravity of the actual earth and sand La is assumed to be Gla. Let L3 be the horizontal distance from the boom support shaft that connects the upper rotating body 3 and boom 4 to the center of gravity Gl, and L4 be the horizontal distance from the arm support shaft that connects the boom 4 and the arm 5 to the center of gravity Gl. Let ΔL be the horizontal distance of Gla. Also, let W be the weight of the earth and sand.

A torque τ3 due to the weight of the earth and sand on the boom support shaft can be expressed by the following equation (9). A torque τ4 due to the weight of the earth and sand on the arm support shaft can be expressed by the following equation (10).

τ3=W(L3−ΔL) (9)
τ4=W(L4−ΔL) (10)

Since the earth and sand weight W is the same in the equations (9) and (10), the following equation (11) is derived.

τ3/(L3−ΔL)=τ4/(L4−ΔL) (11)

Here, the torque τ3 can be obtained from the cylinder pressure of the boom cylinder 7 (boom rod pressure sensor S7R, boom bottom pressure sensor S7B) and attitude sensors (boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3). . The torque τ4 can be obtained from the cylinder pressure of the arm cylinder 8 (arm rod pressure sensor S8R, arm bottom pressure sensor S8B) and attitude sensors (boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3). The center of gravity Gl is a preset value, and the distances L3 and L4 can be obtained by attitude sensors (boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3). The load center-of-gravity calculator 65 can calculate the distance ΔL based on these values and equation (11). That is, the load center-of-gravity calculator 65 can calculate the position of the center-of-gravity Lla of the earth and sand La.

Although the case where the position of the center of gravity of the earth and sand is calculated based on the pressure of the boom cylinder 7 and the pressure of the arm cylinder 8 has been described as an example, the present invention is not limited to this. For example, based on the pressure of the boom cylinder 7 and the pressure of the bucket cylinder 9, the position of the center of gravity of the earth and sand may be calculated. Alternatively, the position of the center of gravity of the earth and sand may be calculated based on the pressure of the arm cylinder 8 and the pressure of the bucket cylinder 9 . Note that the relational expressions in these cases can be obtained in the same manner, and the description thereof is omitted.

As described above, according to the excavator 100 according to the present embodiment, the weight of excavated earth and sand can be detected. Further, according to the excavator 100 according to the present embodiment, the load center of gravity calculation unit 65 can calculate the center of gravity of the earth and sand, and the weight of the earth and sand can be calculated based on the calculated center of gravity of the earth and sand. As a result, for example, even if the earth and sand loaded on the bucket 6 are uneven, the weight of the earth and sand can be calculated based on the center of gravity of the earth and sand, and the detection accuracy of the earth and sand weight can be improved. can.

Also, the weight of earth and sand loaded on the dump truck can be calculated. As a result, overloading of the dump truck can be prevented. For example, the load capacity of the dump truck is checked by a truck scale or the like before it leaves the work site and goes out onto the public road. If the load exceeds the maximum load, the dump truck must return to the position of the excavator 100 and reduce the amount of earth and sand loaded. Therefore, the operational efficiency of the dump truck is lowered. In addition, the lack of loading of dump trucks increases the total number of dump trucks that transport earth and sand, and reduces the operational efficiency of dump trucks. In contrast, according to the excavator 100 according to the present embodiment, it is possible to load the dump truck with earth and sand while preventing overloading, so it is possible to improve the operation efficiency of the dump truck.

The display device 40 also displays the weight of earth and sand in the bucket 6, the maximum load capacity of the dump truck, the additional load capacity, and the remaining load capacity. As a result, the operator on the shovel 100 can load the dump truck with earth and sand by performing work while referring to these displays.

Although the embodiments and the like of the excavator 100 have been described above, the present invention is not limited to the above-described embodiments and the like, and various modifications and improvements can be made within the scope of the gist of the invention described in the claims. is possible.

Although it has been described that the load weight calculation unit 61 calculates the weight of the earth and sand based on the pressure of the bucket cylinder 9 (the boom cylinder 7 and the arm cylinder 8), the method of calculating the weight of the earth and sand is not limited to this. . The load weight calculation unit 61 may calculate the weight of the earth and sand based on the turning torque when turning the upper turning body 3 .

A case will be described where the load weight calculator 61 calculates the weight of earth and sand based on the revolving torque when the upper revolving body 3 revolves. The equation of motion of the turning torque τ when turning the upper turning body 3 can be expressed by the following equation (12). Note that the attachment angle θ includes the boom angle, arm angle, and bucket angle.

Further, the equation of motion of the turning torque τ ₀ when turning the upper turning body 3 when there is no earth and sand in the bucket 6 (when the bucket is empty) can be expressed by the following equation (13).

Further, the equation of motion of the turning torque _τw when turning the upper turning body 3 when there is earth and sand in the bucket 6 can be expressed by the following equation (14).

Here, from the equations (13) and (14), the difference Δτ between the turning torque τ _w in the presence of earth and sand and the turning torque τ ₀ in the absence of earth and sand can be expressed by the following equation (15). .

Here, since the parameters other than the load weight M in Equation (15) are known or measurable, the load weight M can be calculated.

That is, the load weight calculator 61 acquires the swing driving force of the upper swing body 3 during the swing motion of the upper swing body 3 . Here, the swing driving force of the upper swing body 3 is obtained from the pressure difference between one port and the other port of the swing hydraulic motor 2A, that is, the difference in hydraulic pressure detected by the hydraulic sensors 21 and 22 .

Also, the load weight calculator 61 acquires the attitude of the attachment by means of the attitude sensor. For example, the attachment angles (boom angle, arm angle, bucket angle) are acquired by the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3. Also, the inclination angle of the aircraft may be acquired by the aircraft inclination sensor S4. Further, the load weight calculator 61 acquires the turning angular velocity and turning angle of the upper turning body 3 from the turning state sensor S5.

Moreover, the load weight calculator 61 has a table in advance. On the table, the load weight M is associated with the attitude of the attachment and the turning driving force.

Accordingly, the load weight calculator 61 can calculate the load weight M based on the turning driving force, the information of the attitude sensor, and the table.

Further, the load weight calculator 61 may obtain the swing inertia from the swing driving force, and calculate the load weight M based on the swing inertia thus obtained.

Here, the turning inertia when there is no earth and sand in the bucket 6 can be obtained from the posture of the attachment and known information (the position of the center of gravity of each part, the weight, etc.). Also, the turning inertia when the bucket 6 has earth and sand can be calculated from the turning torque.

The amount of increase from the turning inertia without earth and sand to the turning inertia with earth and sand is based on the weight of earth and sand in the bucket 6 . Therefore, the load weight M can be calculated by comparing the turning inertia in the absence of earth and sand with the turning inertia in the presence of earth and sand. In other words, the load weight M can be calculated based on the difference between these turning inertias.

Here, the position of the center of gravity of earth and sand is included in the terms of Jw and hw in Equation (14). By calculating the center-of-gravity position of the earth and sand by the load center-of-gravity calculator 65, it is possible to improve the calculation accuracy even when the load weight M is calculated using the turning torque of the upper swing body 3. FIG.

In addition, the turning driving force includes the influence of inertia moment and turning centrifugal force. Therefore, the method of calculating the earth and sand weight in the load weight calculator 61 can directly obtain the load weight M without requiring complicated compensation when calculating the weight of the load.

Although the excavator 100 has been described as an example in which the upper revolving body 3 revolves, the present invention is not limited to this. For example, when the upper swing body 3 swings and the attachment has a velocity component in a direction other than the swing direction, the load weight M may be obtained in consideration of the speed of the attachment. For example, when the bucket 6 moves away from or approaches the rotation axis of the upper rotating body 3, or when the bucket 6 moves upward or downward along the rotating axis of the upper rotating body 3, the speed of the bucket 6 is The load weight M may be determined by taking this into account.

100 Excavator 1 Undercarriage 2 Swing Mechanism 2A Swing Hydraulic Motor 2A1 First Port 2A2 Second Port 3 Upper Slewing Body 4 Boom (Attachment)
5 Arm (Attachment)
6 bucket (attachment)
7 boom cylinder 8 arm cylinder 9 bucket cylinders 21, 22 oil pressure sensor 30 controller (control device)
40 display device 42 input device 43 audio output device 47 storage device 60 sediment load processing section 61 load weight calculation section (weight calculation section)
62 Maximum loading amount detection unit 63 Additional loading amount calculation unit 64 Remaining loading amount calculation unit 65 Loaded object gravity center calculation unit (gravity center calculation unit)
S1 Boom angle sensor S2 Arm angle sensor S3 Bucket angle sensor S4 Body tilt sensor S5 Turning state sensor S6 Imaging device S7R Boom rod pressure sensor S7B Boom bottom pressure sensor S8R Arm rod pressure sensor S8B Arm bottom pressure sensor S9R Bucket rod pressure sensor S9B Bucket Bottom pressure sensor DT Dump truck

Claims (2)

a lower running body;
an upper revolving body rotatably mounted on the lower traveling body via a revolving mechanism;
an attachment attached to the upper swing structure and having a boom, an arm and a bucket;
an imaging device that captures an image of a load loaded on the bucket;
a controller;
The control device is
a center-of-gravity calculation unit that calculates the center of gravity of the load;
a weight calculation unit that calculates the weight of the load based on the calculated center of gravity of the load,
The center-of-gravity calculation unit
estimating the shape of the upper surface of the load based on at least one of the type and state of the load;
estimating the overall shape of the load based on the shape of the load imaged by the imaging device , the estimated shape of the upper surface of the load, and shape information of the inner surface of the bucket;
calculating the center of gravity of the load based on the estimated overall shape of the load;
Excavator. The imaging device is a stereo camera,
Shovel according to claim 1 .

Images