JP7395521B2 - Excavators and excavator systems - Google Patents

Description

The present disclosure relates to excavators and the like.

In recent years, information technology (IT) has been increasingly used in construction machinery at construction sites and civil engineering sites. For example, various construction information such as excavation depth and slope angle of earthworks is converted into two-dimensional or three-dimensional data. Construction information converted into data is displayed as a graphic on the display screen of a construction machine such as an excavator. The operator can operate the shovel or the like using the construction information displayed on the display screen.

In the technique disclosed in Patent Document 1 below, target terrain and a shovel bucket are displayed on a display screen. The operator can perform excavation work with high precision while checking the target terrain displayed on the display screen and the position of the bucket.

Japanese Patent Application Publication No. 2001-98585

An object of the present disclosure is to provide a shovel or the like that can improve the operability of work performed while checking graphics displayed on a display device.

In one embodiment of the present disclosure,
a lower running body;
an upper rotating body rotatably mounted on the lower traveling body;
a work element mounted on the upper revolving body and including a boom, an arm, and a bucket;
a display device that displays the target shape of the excavation object and the bucket on a display screen in a manner that allows the relative positional relationship between the two to be recognized;
a control device that operates the work element according to the amount of operation of the operating device;
When a figure displayed on the display screen showing the relative positional relationship between the target shape of the excavation object and the bucket is enlarged, the control device controls the boom and the reducing the sensitivity of the movement of the arm and the bucket ;
A shovel will be provided.

Additionally, in other embodiments of the present disclosure,
Displaying the target shape of an object to be excavated by work elements including a boom, an arm, and a bucket of a shovel and the bucket on a display screen in a manner that allows the relative positional relationship between the two to be recognized;
When a graphic representing the relative positional relationship between the target shape of the excavation object and the bucket displayed on the display screen is enlarged, the relationship between the boom, the arm, and the bucket relative to the operation amount of the operating device is enlarged. reduce the sensitivity of movement,
An excavator system is provided.

When the figure is enlarged, the sensitivity of the operation of the work element to the amount of operation of the operating device is reduced, so positioning of the work element becomes easier and workability can be improved.

FIG. 2 is a side view of an excavator according to an embodiment. FIG. 2 is a front view of a display device for an excavator according to an embodiment. FIG. 3 is a diagram showing a figure before enlargement and a figure after enlargement that are displayed on a display screen of a display device. FIG. 1 is a block diagram of an excavator according to an embodiment. 7 is a graph illustrating an example of the relationship between the enlargement rate of a figure and the sensitivity of the operation of a work element. It is a graph which shows an example of the relationship between the operation amount of an operating device, and the command value of a pilot pressure command signal. It is a graph which shows an example of the relationship between a figure enlargement rate and the command value of an engine rotation speed command signal. It is a graph showing an example of the relationship between the figure enlargement ratio and the discharge amount per rotation of the main pump. FIG. 7 is a block diagram for explaining feedback control of a hydraulic actuator in an excavator according to another embodiment. 10 is a graph showing an example of the relationship between the operation amount of the shovel and the operating speed of the hydraulic actuator according to the embodiment shown in FIG. 9.

An excavator according to an embodiment will be described with reference to FIGS. 1 to 8.

FIG. 1 shows a side view of an excavator according to an embodiment. An upper rotating body 11 is rotatably mounted on the lower traveling body 10. A working element 15 for excavating an object to be excavated is mounted on the upper revolving body 11. The work element 15 includes a boom 12 connected to the revolving superstructure 11, an arm 13 connected to the tip of the boom 12, and a bucket 14 connected to the tip of the arm 13.

The boom 12 is driven vertically by a boom cylinder 16. The arm 13 is driven by an arm cylinder 17 to open and close the boom 12 . The bucket 14 is driven by a bucket cylinder 18 to open and close the arm 13 . A hydraulic actuator (hydraulic cylinder) is used for the boom cylinder 16, arm cylinder 17, and bucket cylinder 18.

Attitude sensors 21, 22, and 23 are attached to boom 12, arm 13, and bucket 14, respectively. Posture sensors 21, 22, and 23 detect the postures of boom 12, arm 13, and bucket 14, respectively. As an example, posture sensors 21, 22, and 23 detect the angles of boom 12, arm 13, and bucket 14, respectively, with respect to a horizontal plane.

As another configuration, the attitude sensor 21 detects the angle of the boom 12 with respect to the rotation axis of the upper rotating body 11, the attitude sensor 22 detects the angle of the arm 13 with respect to the boom 12, and the attitude sensor 23 detects the angle of the bucket 14 with respect to the arm 13. An angle may also be detected. Furthermore, as another configuration, the posture sensors 21, 22, and 23 may detect the expansion/contraction lengths of the boom cylinder 16, arm cylinder 17, and bucket cylinder 18, respectively.

A cabin 30 is mounted on the upper revolving body 11. An operating device 31 and a display device 32 are arranged inside the cabin 30. An operator boards the cabin 30 and operates the operating device 31 to operate the work element 15, thereby performing excavation work or the like. The display device 32 displays guidance information that is referred to during excavation work as a graphic.

FIG. 2 shows a front view of the display device 32. The display device 32 includes a display screen 33 that displays graphics, and an input device 34 that inputs instructions to enlarge or reduce the graphics displayed on the display screen 33. On the display screen 33, the target shape 35 of the excavation object and the work element 15 are displayed as figures in a manner that allows the relative positional relationship between the two to be recognized. The input device 34 includes, for example, an enlarge button that instructs to enlarge a figure, and a reduce button that instructs to reduce a figure. As another configuration, a touch panel may be used for the display screen 33, and this touch panel may be used as an input device. In this case, an enlargement button and a reduction button may be displayed on the display screen 33, or an instruction to enlarge or reduce may be given by a pinch-out operation and a pinch-in operation.

Display device 32 further includes a calibration button 36. By pressing the calibration button 36 with the tip of the bucket 14 (FIG. 1) positioned at the reference point of the excavation object, the relative positional relationship between the target shape 35 in the display screen 33 and the work element 15 can be calibrated. It can be performed.

FIG. 3 shows a figure displayed on the display screen 33 before enlargement and a figure after enlargement. The upper figure in FIG. 3 shows the image before enlargement, and the lower figure shows the image after enlargement. On the display screen 33 before the figure is enlarged, the figure of the entire shovel including the work element 15 and the target shape 35 are displayed. When the input device 34 (FIG. 1) is operated to instruct the enlargement of a figure, the figure displayed on the display screen 33 is enlarged and the tip of the bucket 14 is displayed within the display screen 33. , panning of the enlarged figure is automatically performed. Here, "panning" means moving a large figure (or image) that cannot fit on the display screen 33 vertically and horizontally to display a specific part of the figure on the display screen 33.

Next, a case will be described in which the figure enlargement rate is gradually increased from the figure before enlargement shown in FIG. 3. When the figure is gradually enlarged under the condition that the center position of the figure before enlargement is not displaced within the display screen 33, first, the rear end of the shovel and the rear wheel of the crawler are removed from the display screen 33. At this time, the tip of the bucket 14 is displayed on the periphery of the display screen 33. If the figure enlargement ratio is further increased under the condition that the center position of the figure before enlargement is not displaced, the tip of the bucket 14 will come off the display screen 33. In the embodiment, the state in which the tip of the bucket 14 is displayed on the display screen 33 is maintained by panning the enlarged figure. In addition, in the middle of gradually increasing the figure enlargement rate, the figure enlargement rate is increased so that the tip of the bucket 14 is continuously displayed in a certain area (near center area) including the center of the display screen 33. Panning may be performed little by little.

By panning the enlarged figure, the operator can visually confirm the relative positional relationship between the tip of the bucket 14 and the target shape 35 during the enlargement of the figure and even during the enlargement stage. Thereby, the excavation work can be performed while checking the relative positional relationship between the tip of the bucket 14 and the target shape 35.

FIG. 4 shows a block diagram of the excavator according to the embodiment. The main pump 69 is driven by the power output from the engine 68. Hydraulic oil discharged from the main pump 69 is supplied to the control valve 70. The control valve 70 distributes hydraulic oil to a plurality of hydraulic actuators based on commands from the control device 50. The plurality of hydraulic actuators include a boom cylinder 16, an arm cylinder 17, a bucket cylinder 18, a swing hydraulic motor 80, a right travel hydraulic motor 81, and a left travel hydraulic motor 82. The swing hydraulic motor 80 swings the upper swing structure 11 (FIG. 1). The right travel hydraulic motor 81 and the left travel hydraulic motor 82 drive the right and left crawlers of the lower traveling body 10, respectively.

A signal S1 representing the amount of operation of the operation device 31 is input from the operation device 31 to the amount of operation detection section 51 of the control device 50. The signal S1 may be an electrical signal or a hydraulic signal. The manipulated variable detection section 51 generates manipulated variable data D1 based on the input signal S1.

The graphic display sensitivity generation unit 52 determines the target shape 35 (FIG. 2) of the excavated object based on the construction data 53 stored in advance in the storage device of the control device 50, and displays it on the display screen 33 of the display device 32. do. Furthermore, the shape of the shovel including the work element 15 (FIG. 1) is displayed on the display screen 33 based on the current position information of the shovel.

Detection values S2 of the posture sensors 21, 22, and 23 are input to the graphic display sensitivity generation section 52 of the control device 50. The graphic display sensitivity generation unit 52 calculates the current posture of the work element 15 based on the detection values S2 of the posture sensors 21, 22, and 23. The current posture of the work element 15 of the shovel is reflected in the figure of the work element 15 of the shovel displayed on the display screen 33.

The relative positional relationship between the target shape 35 and the work element 15 can be calibrated by operating the calibration button 36 (FIG. 2) with the tip of the bucket 14 aligned with the reference point of the excavated object. good.

The graphic display sensitivity generation unit 52 further generates sensitivity data D2 of the operation of the work element based on the current enlargement rate of the graphic. Here, "sensitivity of the operation of the work element" means the degree of movement of the tip of the work element 15 (the tip of the bucket 14) with respect to a change in the amount of operation of the operating device 31. When the sensitivity data D2 of the operation of the work element 15 is large, the amount of movement of the tip of the work element 15 is larger than when it is small, even if the change in the operation amount is small. Conversely, when the sensitivity data D2 of the motion of the work element 15 is small, the amount of movement of the tip of the work element 15 is smaller than when it is large, even if the change in the operation amount is large.

FIG. 5 shows an example of a graph defining the relationship between the enlargement rate of a figure and the sensitivity of the operation of a work element. The horizontal axis represents the figure magnification rate, and the vertical axis represents the sensitivity of the operation of the work element. As the figure magnification increases, the sensitivity of the operation of the work element decreases.

A pilot pressure command generation unit 54 of the control device 50 (FIG. 4) generates a pilot pressure command signal S3 based on the manipulated variable data D1 and the sensitivity data D2. Pilot pressure command signal S3 is generated for each hydraulic actuator.

The pilot pressure control valve 60 receives the pilot pressure command signal S3 and generates a hydraulic signal P3 by converting the primary pilot pressure (the discharge pressure of the pilot pump) into the secondary pilot pressure. A control circuit 61 controls the opening degree of the control valve 70 based on the oil pressure signal P3. Thereby, the flow rate of hydraulic oil supplied to each hydraulic actuator is controlled.

The set value of the throttle volume 37 is input to the engine rotation speed command generating section 56 of the control device 50 . The engine rotation speed command generation unit 56 generates an engine rotation speed command signal S4 based on the setting value of the throttle volume 37, the operation amount data D1, and the sensitivity data D2. Engine control unit 67 receives engine rotation speed command signal S4 and controls engine 68 so that the rotation speed of engine 68 approaches the command value.

Pump horsepower command generation section 55 of control device 50 generates horsepower control signal S5 based on manipulated variable data D1 and sensitivity data D2. The horsepower control valve 64 receives the horsepower control signal S5 and generates a hydraulic signal P5 used for horsepower control of the main pump 69 by converting the primary pilot pressure to the secondary pilot pressure.

The control circuit 65 receives the hydraulic signal P5 and controls the tilt angle of the swash plate of the main pump 69. Thereby, the discharge amount per rotation of the main pump 69 can be increased or decreased.

Next, with reference to FIGS. 6 to 8, a method for changing the degree of movement of the tip of the working element 15 based on the sensitivity data D2 will be described using three examples.

In the example shown in FIG. 6, the degree of movement of the tip of the work element 15 is changed by changing the command value of the pilot pressure command signal S3 generated by the pilot pressure command generation unit 54 (FIG. 4) according to the sensitivity data D2. change.

FIG. 6 shows an example of the relationship between the operation amount of the operating device 31 (FIG. 4) and the command value of the pilot pressure command signal S3. The horizontal axis represents the manipulated variable, and the vertical axis represents the command value of the pilot pressure command signal S3. The relationship between the manipulated variable and the pilot pressure command signal S3 is defined for each graphic enlargement ratio. When the manipulated variable exceeds the upper limit of the dead zone, the pilot pressure command signal S3 increases as the manipulated variable increases. As the enlargement ratio of the figure increases, the slope of the pilot pressure command signal S3 with respect to the manipulated variable becomes smaller. In other words, as the enlargement ratio of the figure increases, the ratio of variation in the pilot pressure command signal S3 to variation in the manipulated variable becomes smaller.

When the fluctuation in the pilot pressure command signal S3 becomes smaller, the fluctuation in the flow rate of the hydraulic oil supplied to the hydraulic actuator also becomes smaller. This reduces the degree of movement of the tip of the working element 15 with respect to changes in the amount of operation of the operating device 31. In other words, the sensitivity of the movement of the tip of the working element 15 is reduced.

In the example shown in FIG. 7, the tip of the work element 15 is moved by changing the command value of the engine speed command signal S4 generated by the engine speed command generation unit 56 (FIG. 4) according to the sensitivity data D2. change the degree of

FIG. 7 shows the enlargement ratio of the figure and the correction coefficient of the engine rotation speed command in the unit of "%". In a typical excavator, the command value of the engine speed is set by the operator operating the throttle volume 37 (FIG. 4). The rotation speed of the engine 68 is controlled to match the command value set by the throttle volume 37.

In the example shown in FIG. 7, the engine rotation speed correction coefficient is 100% when the figure enlargement rate is the smallest, and as the figure enlargement rate increases, the engine rotation speed correction coefficient becomes smaller. The engine rotation speed command generation unit 56 (FIG. 4) generates the engine rotation speed command signal S4 by multiplying the engine rotation speed command value set by the throttle volume 37 by the correction coefficient determined from FIG. Therefore, as the enlargement ratio of the figure increases, the command value of the engine rotation speed command signal S4 decreases. As a result, the amount of hydraulic oil discharged from the main pump 69 (FIG. 4) decreases, and the degree of movement of the tip of the working element 15 in response to changes in the amount of operation of the operating device 31 decreases. In other words, the sensitivity of the movement of the tip of the working element 15 is reduced.

In the example shown in FIG. 8, the degree of movement of the tip of the work element 15 is controlled by changing the command value of the horsepower control signal S5 generated by the pump horsepower command generation unit 55 (FIG. 4) according to the sensitivity data D2. change. As the command value of the horsepower control signal S5 increases, the discharge amount per rotation of the main pump 69 (FIG. 4) increases.

FIG. 8 shows an example of the relationship between the figure enlargement ratio and the discharge amount per rotation of the main pump 69. The horizontal axis represents the enlargement rate of the figure, and the vertical axis represents the discharge amount per rotation of the main pump 69. Even if the amount of operation is the same, the discharge amount per revolution of the main pump 69 decreases as the enlargement ratio of the figure increases. As a result, the degree of movement of the tip of the working element 15 with respect to a change in the amount of operation of the operating device 31 becomes smaller. In other words, the sensitivity of the movement of the tip of the working element 15 is reduced.

Next, the excellent effects of the above embodiment will be explained.

If the sensitivity of the operation of the work element 15 remains unchanged even when the figure displayed on the display screen 33 (FIG. 3) is enlarged, even if the amount of operation of the operation device 31 is small, the tip of the bucket 14 moves significantly within the display screen 33. Reducing the sensitivity of the operation of the work element 15 when the figure is enlarged reduces the amount of movement of the tip of the bucket 14 within the display screen 33. Therefore, when the operator performs the operation while looking at the display screen 33, it is possible to reduce the sense of discomfort given to the operator when enlarging the figure.

When an operator wants to perform work while increasing the positional accuracy of the tip of the bucket 14, it is conceivable that the figure displayed on the display screen 33 is enlarged. When the magnification of the figure increases and the sensitivity of the operation of the work element 15 decreases, it becomes easier to position the tip of the bucket 14 with high precision. Therefore, the operation feeling as intended by the operator can be obtained.

A method of adjusting the sensitivity of the operation of the work element 15 by the command value of the pilot pressure command signal S3 shown in FIG. 6, and a method of adjusting the sensitivity of the operation of the work element 15 by the command value of the engine rotation speed command signal S4 shown in FIG. The following three methods may be used in combination: a method of adjusting the sensitivity of the operation of the work element 15 using the command value of the horsepower control signal S5 shown in FIG.

Next, other embodiments will be described with reference to FIGS. 9 and 10. Hereinafter, differences from the embodiments shown in FIGS. 1 to 8 will be explained, and explanations of common configurations will be omitted. In the embodiments shown in FIGS. 1 to 8, open-loop control is applied to the control of the work element 15. In contrast, in this embodiment, closed loop control is applied to control the work element 15.

FIG. 9 shows a block diagram of feedback control of the hydraulic actuator in the excavator according to this embodiment. In FIG. 9, the boom cylinder 16 is shown as the hydraulic actuator, but the control of the other hydraulic actuators is also similar to the control of the boom cylinder 16.

A flow rate sensor 57 is attached to a flow path of hydraulic oil supplied to the boom cylinder 16. The detected value of the flow rate sensor 57 is fed back to the pilot pressure command generation section 54 of the control device 50. The pilot pressure command generation unit 54 calculates a target value for the operating speed of the boom cylinder 16 based on the operation amount data D1 and the sensitivity data D2. The relationship between the operation amount data D1 and the target value of the operating speed may be defined in advance by a correspondence table or by a function.

The pilot pressure command generation unit 54 calculates the operating speed of the boom cylinder 16 based on the flow rate of hydraulic oil supplied to the boom cylinder 16. The command value of the pilot pressure command signal S3 is determined so that the calculated value of the operating speed matches the target value of the operating speed. By performing closed-loop control in this manner, the operator can operate the hydraulic actuator at the intended operating speed.

FIG. 10 shows an example of the relationship between the operation amount and the operating speed of the hydraulic actuator. The horizontal axis represents the amount of operation, and the vertical axis represents the operating speed of the hydraulic actuator. As the amount of operation increases, the operating speed of the hydraulic actuator increases. As the enlargement ratio of the figure increases, the slope of the operating speed of the hydraulic actuator with respect to the operation amount becomes smaller. When the amount of operation is the same, the larger the enlargement ratio of the figure, the slower the operating speed of the hydraulic actuator becomes. As a result, the degree of movement of the tip of the working element 15 with respect to a change in the amount of operation of the operating device 31 becomes smaller. In other words, the sensitivity of the movement of the tip of the working element 15 is reduced.

In the embodiments shown in FIGS. 9 and 10, as in the embodiments shown in FIGS. 1 to 8, it is possible to reduce the sense of discomfort given to the operator when the operator performs an operation while looking at the display screen 33. In addition to this, it also provides the operator with the desired operating feel.

In the above embodiment, the target shape 35 displayed on the display screen 33 (FIG. 2) is defined by the intersection line of the target surface of the excavation object, the vertical plane, and the vertical plane. That is, the target shape 35 was displayed on the display screen 33 as a two-dimensional figure in a vertical plane.

The construction data 53 (FIG. 4) that defines the target shape of the excavated object is originally three-dimensional image data. The target shape 35 may be displayed as a three-dimensional image on the display screen 33 based on this three-dimensional image data. In this case, the sensitivity of the 15 operations of the work elements may be adjusted based on the magnification rate of the three-dimensional image.

Although the present invention has been described above along with examples, the present invention is not limited to these. For example, it will be obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

10 Lower traveling body 11 Upper rotating body 12 Boom 13 Arm 14 Bucket 15 Working element 16 Boom cylinder 17 Arm cylinder 18 Bucket cylinder 21, 22, 23 Attitude sensor 30 Cabin 31 Operating device 32 Display device 33 Display screen 34 Input device 35 Excavation target Target shape of object 36 Calibration button 37 Throttle volume 50 Control device 51 Manipulated amount detection section 52 Graphic display sensitivity generation section 53 Construction data 54 Pilot pressure command generation section 55 Pump horsepower command generation section 56 Engine speed command generation section 57 Flow rate sensor 60 Pilot pressure control valve 61 Control circuit 64 Horsepower control valve 65 Control circuit 67 Engine control unit 68 Engine 69 Main pump 70 Control valve 80 Swing hydraulic motor 81 Right travel hydraulic motor 82 Left travel hydraulic motor D1 Operation amount data D2 Sensitivity data P3, P5 Oil pressure signal S1 Signal representing operation amount S2 Detection value of attitude sensor S3 Pilot pressure command signal S4 Engine speed command signal S5 Horsepower control signal

Claims (4)

a lower running body;
an upper rotating body rotatably mounted on the lower traveling body;
a work element mounted on the upper revolving body and including a boom, an arm, and a bucket;
a display device that displays the target shape of the excavation object and the bucket on a display screen in a manner that allows the relative positional relationship between the two to be recognized;
a control device that operates the work element according to the amount of operation of the operating device;
When a figure displayed on the display screen showing the relative positional relationship between the target shape of the excavation object and the bucket is enlarged, the control device controls the boom and the reducing the sensitivity of the movement of the arm and the bucket ;
shovel. comprising an input device for inputting an instruction to enlarge or reduce the figure;
The input device is a button or a touch panel,
The excavator according to claim 1. The control device enlarges the graphic so that the tip of the bucket remains displayed on the display screen.
The excavator according to claim 1 or 2. Displaying the target shape of an object to be excavated by work elements including a boom, an arm, and a bucket of a shovel and the bucket on a display screen in a manner that allows the relative positional relationship between the two to be recognized;
When a graphic representing the relative positional relationship between the target shape of the excavation object and the bucket displayed on the display screen is enlarged, the relationship between the boom, the arm, and the bucket relative to the operation amount of the operating device is enlarged. reduce the sensitivity of movement,
excavator system.

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