Work machinery

Abstract

To provide a work machine capable of holding sediment evenly all over an opening of a bucket.SOLUTION: A work machine includes a controller that drives a boom, an arm 32, and a bucket 33 to make a series of operation from digging up sediment in a digging target to discharging the sediment to a discharging target be performed automatically. The controller controls the boom, the arm 32, and the bucket 33 so that after making the sediment in the digging target be dug up, shaking operation is performed before discharging the sediment to the discharging target is made to be performed. The shaking operation is operation of making the arm 32 stop after moving, from a state of holding the sediment using the bucket 33, to the side opposite to a machine body by a predetermined distance at speed equal to or higher than predetermined speed.SELECTED DRAWING: Figure 3B

Description

[Technical Field]

[0001] The present invention relates to a work machine that automatically performs a series of operations from excavating earth and sand to discharging the earth. [Background technology]

[0002] Patent Document 1 discloses an automatically operated hydraulic excavator that automatically repeats excavation, forward swing, earth dumping, and return swing. After the excavation operation is completed and before the forward swing operation begins, the opening of the bucket is tilted once in the bucket dump direction, allowing excess earth and rocks held in the bucket to fall naturally. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-115272 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when soil is scooped up with a bucket, the soil may be concentrated toward the tip of the bucket. If an attempt is made to remove the excess soil from the bucket in this state, more soil than necessary will fall. Therefore, it is desirable to retain the soil evenly throughout the entire bucket opening.

[0005] An object of the present invention is to provide a work machine that is capable of holding soil and sand evenly over the entire opening of the bucket. [Means for solving the problem]

[0006] The present invention comprises a machine body, a boom attached to the machine body so as to be rotatable in the vertical direction, an arm attached to the boom so as to be rotatable in the vertical direction, a bucket attached to the arm so as to be rotatable, and a controller that drives the boom, the arm, and the bucket to automatically perform a series of operations from excavating soil within an excavation target to discharging it to a discharge target, wherein the controller controls the boom, the arm, and the bucket so that after excavating the soil within the excavation target, a sift operation is performed and then the soil is discharged to the discharge target, and the sift operation is an operation in which the arm, while holding the soil in the bucket, moves a predetermined distance at a predetermined speed or more in the opposite direction to the machine body and stops. [Effects of the Invention]

[0007] According to the present invention, after the soil is excavated from the excavation target, a sifting operation is performed, and then the soil is discharged to the discharge target. During the sifting operation, the arm is moved at a predetermined speed or faster, causing the soil in the bucket to move in the direction of the arm's movement along with the bucket. When the arm is moved a predetermined distance and stopped, the soil in the bucket moves in the direction of the arm's movement due to inertia and stops. This movement of soil may shake off excess soil in the bucket. In this case, soil can be prevented from spilling from the bucket after the sifting operation until the soil is discharged to the discharge target. Furthermore, if soil is concentrated toward the tip of the bucket, this movement of soil may even out the concentration of soil. In this case, soil can be held evenly throughout the entire opening of the bucket. Therefore, soil can be prevented from spilling from the bucket after the sifting operation until the soil is discharged to the discharge target. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a work machine. [Figure 2] FIG. 2 is a circuit diagram of the work machine. [Figure 3A]FIG. 2 is a side view of the arm and bucket, showing the state in which the bucket is holding earth and sand. [Figure 3B] FIG. 10 is a side view of the arm and bucket, showing a state in which the arm is moved to the opposite side from the machine body while the bucket is rotated so that the opening surface of the bucket is horizontal. [Figure 3C] FIG. 10 is a side view of the arm and bucket, showing a state in which the arm has stopped rotating. [Figure 4] 10 is a flowchart of an automatic driving process. [Figure 5A] FIG. 10 is a side view of the arm and bucket in a modified example, showing the state in which the bucket holds earth and sand. [Figure 5B] FIG. 10 is a side view of the arm and bucket in a modified example, showing a state in which the bucket is in a cradle-holding position. [Figure 5C] FIG. 10 is a side view of the arm and bucket in a modified example, showing a state in which the arm is moved to the opposite side from the machine body while the bucket is rotated so that the opening surface of the bucket is horizontal. [Figure 5D] FIG. 10 is a side view of the arm and bucket in the modified example, showing a state in which the rotation of the arm has stopped. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0010] (Work machine configuration) A work machine according to an embodiment of the present invention automatically performs a series of operations from excavating earth and sand to discharging the earth. As shown in Fig. 1, which is a side view of a work machine 1, the work machine 1 is a machine that performs work using an attachment 30, such as a hydraulic excavator. The work machine 1 has a machine main body 24 having a lower traveling body 21 and an upper rotating body 22, the attachment 30, and a cylinder 40.

[0011] The lower traveling body 21 is a part that allows the work machine 1 to travel, and is equipped with, for example, crawlers. The upper rotating body 22 is attached to the upper part of the lower traveling body 21 so as to be able to rotate via a rotating device 25. A cab (operator's compartment) 23 is provided at the front of the upper rotating body 22.

[0012] The attachment 30 is attached to the upper rotating body 22 so as to be rotatable in the vertical direction. The attachment 30 includes a boom 31, an arm 32, and a bucket 33. The boom 31 is attached to the upper rotating body 22 so as to be rotatable (raised and lowered) in the vertical direction. The boom 31 rotates around a boom foot pin 31a, which serves as its fulcrum. The arm 32 is attached to the boom 31 so as to be rotatable in the vertical direction. The bucket 33 is attached to the arm 32 so as to be rotatable in the front-to-rear direction. The bucket 33 is used for tasks such as digging, leveling, and scooping earth and sand.

[0013] The cylinder 40 is capable of hydraulically rotating the attachment 30. The cylinder 40 is a hydraulic telescopic cylinder. The cylinder 40 includes a boom cylinder 41, an arm cylinder 42, and a bucket cylinder 43.

[0014] The boom cylinder 41 rotates the boom 31 relative to the upper rotating body 22. A base end of the boom cylinder 41 is rotatably attached to the upper rotating body 22. A tip end of the boom cylinder 41 is rotatably attached to the boom 31.

[0015] The arm cylinder 42 rotates the arm 32 relative to the boom 31. A base end of the arm cylinder 42 is rotatably attached to the boom 31. A tip end of the arm cylinder 42 is rotatably attached to the arm 32.

[0016] The bucket cylinder 43 rotates the bucket 33 relative to the arm 32. A base end of the bucket cylinder 43 is rotatably attached to the arm 32. A tip end of the bucket cylinder 43 is rotatably attached to a link member 34 that is rotatably attached to the bucket 33.

[0017] The work machine 1 also has an angle sensor 52 and an inclination angle sensor 60 .

[0018] The angle sensor 52 detects the rotation angle of the upper rotating body 22 relative to the lower traveling body 21. The angle sensor 52 is, for example, an encoder, a resolver, or a gyro sensor. In this embodiment, the rotation angle of the upper rotating body 22 when the front of the upper rotating body 22 coincides with the front of the lower traveling body 21 is defined as 0°.

[0019] The inclination angle sensor 60 detects the attitude of the attachment 30. The inclination angle sensor 60 includes a boom inclination angle sensor 61, an arm inclination angle sensor 62, and a bucket inclination angle sensor 63.

[0020] The boom inclination angle sensor 61 is attached to the boom 31 and detects the attitude of the boom 31. The boom inclination angle sensor 61 is a sensor that acquires the inclination angle of the boom 31 with respect to the horizontal line, and is, for example, an inclination (acceleration) sensor. The boom inclination angle sensor 61 may also be a rotation angle sensor that detects the rotation angle of the boom foot pin 31a (boom base end) or a stroke sensor that detects the stroke amount of the boom cylinder 41.

[0021] The arm inclination angle sensor 62 is attached to the arm 32 and detects the posture of the arm 32. The arm inclination angle sensor 62 is a sensor that acquires the inclination angle of the arm 32 with respect to the horizontal line, and is, for example, an inclination (acceleration) sensor. The arm inclination angle sensor 62 may be a rotation angle sensor that detects the rotation angle of the arm connecting pin (base end of the arm) or a stroke sensor that detects the stroke amount of the arm cylinder 42.

[0022] The bucket inclination angle sensor 63 is attached to the link member 34 and detects the attitude of the bucket 33. The bucket inclination angle sensor 63 is a sensor that acquires the inclination angle of the bucket 33 with respect to the horizontal line, and may be, for example, an inclination (acceleration) sensor. The bucket inclination angle sensor 63 may also be a rotation angle sensor that detects the rotation angle of the bucket connecting pin (bucket base end) or a stroke sensor that detects the stroke amount of the bucket cylinder 43.

[0023] The work machine 1 also has an imaging device 55. The imaging device 55 is attached to the boom 31, for example. The imaging device 55 may also be installed in a location remote from the work machine 1. In this embodiment, the imaging device 55 is a camera, and captures an image of at least the bucket 33. The imaging device 55 may also be a lidar (LIDAR), an ultrasonic sensor, a millimeter-wave radar, a stereo camera, a distance image sensor, an infrared sensor, or the like.

[0024] In this embodiment, the excavation target is a soil pit 70, but it may also be a pile of soil or a container placed directly on the ground. In this embodiment, the soil removal target is a dump truck (not shown), but it may also be a truck.

[0025] (Circuit configuration of work machine) As shown in FIG. 2, which is a circuit diagram of the work machine 1, the work machine 1 has a controller 11 and a storage device 13.

[0026] The controller 11 automatically controls the work machine 1. By driving the boom 31, the arm 32, the bucket 33, and the slewing device 25, the controller 11 causes the work machine 1 to automatically perform a series of operations from digging up earth and sand in the earth and sand pit 70 to discharging the earth and sand onto a dump truck. In other words, the work machine 1 is automatically operated. Specifically, the controller 11 automatically operates the slewing device 25 and the attachment 30 based on the detection values ​​of the angle sensor 52 and the tilt angle sensor 60.

[0027] In this embodiment, the controller 11 controls the boom 31, the arm 32, the bucket 33, and the swing device 25 so that after the soil in the soil pit 70 has been excavated, a sift operation is performed, and then the upper swing body 22 is rotated to position the bucket 33 above the bed of the dump truck. After that, the controller 11 controls the boom 31, the arm 32, the bucket 33, and the swing device 25 so that after the soil has been discharged onto the bed of the dump truck, the upper swing body 22 is rotated to position the bucket 33 above the soil pit 70.

[0028] The sieving operation is an operation in which, while holding soil and sand in the bucket 33, the bucket 33 is rotated so that the opening surface of the bucket 33 is horizontal, and the arm 32 is moved a predetermined distance at a predetermined speed or more in the opposite direction from the machine body 24 and stopped.

[0029] As shown in FIGS. 3A to 3C, which are side views of the arm 32 and the bucket 33, the sieving operation is performed as follows. First, as shown in FIG. 3A, the boom 31, arm 32, and bucket 33 are stopped with the bucket 33 holding earth and sand. Next, as shown in FIG. 3B, the arm 32 is moved toward the opposite side from the machine body 24 (the arm is pushed) while rotating the bucket 33 so that the opening surface of the bucket 33 is horizontal. At this time, the movement speed of the arm 32 is equal to or greater than a predetermined speed. The predetermined speed is a speed faster than the speed of the arm 32 during excavation. Next, as shown in FIG. 3C, when the arm 32 has moved a predetermined distance, the rotation of the arm 32 is stopped. At this time, the opening surface of the bucket 33 is horizontal.

[0030] By moving the arm 32 at a predetermined speed or faster, the soil in the bucket 33 moves in the direction of movement of the arm 32 along with the bucket 33. Then, when the arm 32 is moved a predetermined distance and stopped, the soil in the bucket 33 moves in the direction of movement of the arm 32 due to inertia and stops. This movement of soil may shake off excess soil in the bucket 33. In this case, spillage of soil from the bucket 33 after the sifting operation and before the soil is discharged into the dump truck bed can be prevented. Furthermore, if soil is concentrated toward the tip of the bucket 33, this movement of soil may even out the soil. In this case, soil can be held evenly throughout the entire opening of the bucket 33. Therefore, spillage of soil from the bucket 33 after the sifting operation and before the soil is discharged into the dump truck bed can be prevented.

[0031] During the sieving operation, the bucket 33 is rotated so that the opening of the bucket 33 is horizontal, while the arm 32 is moved a predetermined distance at a predetermined speed or faster in the direction opposite the machine body 24 and then stopped. By horizontalizing the opening of the bucket 33 through the sieving operation, the soil and sand that has been concentrated toward the tip of the bucket 33 can be suitably leveled.

[0032] 3A, controller 11 sets angle θ between opening plane A of bucket 33 and horizontal plane H when bucket 33 scoops up soil and sand to a predetermined angle or more. The predetermined angle θ is, for example, 40 to 60°. This makes it possible to reduce the amount of soil and sand held by bucket 33, and therefore the amount of soil and sand spilling from bucket 33.

[0033] As shown in FIG. 1 , the controller 11 controls the sieving operation by elevating the bucket 33 holding the soil and sand above a predetermined height. The predetermined height is, for example, the height of the boom foot pin 31a. When soil and sand are scooped up at a position lower than the ground in the soil and sand pit 70, the bucket 33 is positioned lower than the ground. If the sieving operation is performed in this state, the machine body 24 may become unstable due to the moment. Therefore, by elevating the bucket 33 holding the soil and sand above a predetermined height, the sieving operation can be performed with the machine body 24 stabilized.

[0034] The controller 11 also sets a predetermined distance for moving the arm 32 during the sieving operation. If the predetermined distance for moving the arm 32 is long, there is a risk that the bucket 33 will hit an obstacle located further back than the earth and sand pit 70 as viewed from the machine body 24. Furthermore, if the object to be excavated is not the earth and sand pit 70 but a container placed on the ground, there is a risk that the bucket 33 will hit the side of the object to be excavated (an obstacle) located further back as viewed from the machine body 24 if the predetermined distance for moving the arm 32 is long. Therefore, the controller 11 sets the predetermined distance to a length that will prevent the bucket 33 from hitting an obstacle located on the opposite side of the machine body 24. The set predetermined distance is stored in the storage device 13.

[0035] The predetermined distance is set as follows: The size of the earth and sand pit 70 is taught in advance, and a safe predetermined distance (that does not extend beyond the earth and sand pit 70) is calculated from the distance between the bucket 33 and the outer periphery of the earth and sand pit 70. Alternatively, an image of the earth and sand pit 70 is captured by the imaging device 55, and the distance between the bucket 33 and the outer periphery of the earth and sand pit 70 is determined, and the safe predetermined distance is calculated.

[0036] By preventing the bucket 33 from hitting an obstacle even when the arm 32 is moved a predetermined distance, the sieving operation can be performed safely.

[0037] Furthermore, the controller 11 does not perform the sifting operation if there is not a predetermined amount of soil or sand at the tip end of the bucket 33 imaged by the imaging device 55. The predetermined amount is the amount at which a leveling effect can be expected from the sifting operation. Therefore, if there is not a predetermined amount of soil or sand at the tip end of the bucket 33, a leveling effect cannot be expected, and there is little need to perform the sifting operation. In this case, by not performing the sifting operation, it is possible to move on to the next operation (swinging operation) earlier.

[0038] (Work machine operation) Next, the operation of the work machine 1 will be described with reference to FIG. 4, which is a flowchart of the automatic driving process.

[0039] First, the controller 11 causes the work machine 1 to perform an excavation operation (step S1). The excavation operation is an operation to excavate earth and sand in the earth and sand pit 70. At this time, the angle θ between the opening plane A of the bucket 33 and the horizontal plane H when the bucket 33 scoops up earth and sand is set to a predetermined angle or more. This makes it possible to reduce the amount of earth and sand held by the bucket 33, and therefore the amount of earth and sand spilling from the bucket 33.

[0040] Next, the controller 11 determines whether the height of the bucket 33 is equal to or greater than a predetermined height (step S2). If it is determined in step S2 that the height of the bucket 33 is not equal to or greater than the predetermined height (S2: NO), the controller 11 raises the bucket 33 to equal to or greater than the predetermined height (step S3). By raising the bucket 33 holding the soil and sand to equal to or greater than the predetermined height, the machine body 24 can then be stabilized to perform the sieving operation. Furthermore, the machine body 24 can then be turned safely.

[0041] In step S2, if it is determined that the height of the bucket 33 is equal to or greater than a predetermined height (S2: YES), or after step S3, the controller 11 determines whether or not there is a predetermined amount of earth and sand on the tip side of the bucket 33 (step S4). In step S4, if it is determined that there is a predetermined amount of earth and sand on the tip side of the bucket 33 (S4: YES), the controller 11 sets a predetermined distance (step S5). By setting the predetermined distance to a length that prevents the bucket 33 from hitting an obstacle, the sieving operation can be performed safely.

[0042] Next, the controller 11 causes the work machine 1 to perform a sift operation (step S6). The sift operation may shake off excess soil and sand in the bucket 33. Also, if soil and sand is concentrated at the tip of the bucket 33, the soil and sand may be leveled out. The controller 11 then proceeds to step S7.

[0043] In the sieving operation, the predetermined speed may be increased or decreased depending on the amount of soil and sand at the tip end of bucket 33. For example, if the amount of soil and sand at the tip end of bucket 33 is greater than the predetermined amount, the predetermined speed can be increased to suitably level the uneven soil and sand.

[0044] If it is determined in step S4 that there is not a predetermined amount of earth and sand on the tip side of the bucket 33 (S4: NO), the controller 11 proceeds to step S7. In other words, the controller 11 does not cause the work machine 1 to perform a sift operation. If there is not a predetermined amount of earth and sand on the tip side of the bucket 33, a leveling effect cannot be expected, and there is little need to perform a sift operation. In this case, not performing a sift operation allows for an early transition to a swing operation.

[0045] In step S7, the controller 11 causes the work machine 1 to perform a swing operation (step S7). This swing operation is an operation of swinging the upper swing body 22 and moving the bucket 33 above the bed of the dump truck. Next, the controller 11 causes the work machine 1 to perform an earth dumping operation (step S8). The earth dumping operation is an operation of dumping earth onto the bed of the dump truck. Next, the controller 11 causes the work machine 1 to perform a swing operation (step S9). This swing operation is an operation of swinging the upper swing body 22 and moving the bucket 33 above the earth and sand pit 70. Then, the process returns to step S1.

[0046] (effect) As described above, with the work machine 1 according to this embodiment, after the soil in the soil pit 70 is excavated, a sift operation is performed, and the soil is then dumped onto the bed of the dump truck. During the sift operation, the arm 32 is moved at a predetermined speed or faster, causing the soil in the bucket 33 to move together with the bucket 33 in the direction of movement of the arm 32. When the arm 32 is moved a predetermined distance and stopped, the soil in the bucket 33 moves within the bucket 33 in the direction of movement of the arm 32 by inertia and stops. This movement of soil may shake off excess soil in the bucket 33. In this case, it is possible to prevent soil from spilling from the bucket 33 after the sift operation until the soil is dumped onto the bed of the dump truck. Furthermore, if soil is concentrated toward the tip of the bucket 33, this movement of soil may even out the concentration of soil. In this case, the soil can be held evenly throughout the entire opening of the bucket 33. Therefore, after the sifting operation, it is possible to prevent earth and sand from spilling out of the bucket 33 until the earth and sand are discharged onto the bed of the dump truck.

[0047] During the sieving operation, the bucket 33 is rotated so that the opening of the bucket 33 is horizontal, while the arm 32 is moved a predetermined distance at a predetermined speed or faster in the direction opposite the machine body 24 and then stopped. By horizontalizing the opening of the bucket 33 through the sieving operation, the soil and sand that has been concentrated toward the tip of the bucket 33 can be suitably leveled.

[0048] Furthermore, when bucket 33 is used to scoop up soil and sand, angle θ between opening plane A of bucket 33 and horizontal plane H is set to a predetermined angle or greater. This makes it possible to reduce the amount of soil and sand held by bucket 33, and therefore the amount of soil and sand spilling from bucket 33.

[0049] Furthermore, the sifting operation is performed with the bucket 33 holding the soil and sand raised above a predetermined height. For example, when soil and sand are scooped up at a position lower than the ground in a soil and sand pit 70, the bucket 33 is positioned lower than the ground. If the sifting operation were performed in this state, the machine body 24 may become unstable due to the moment. Therefore, by raising the bucket 33 holding the soil and sand above a predetermined height, the sifting operation can then be performed with the machine body 24 stabilized.

[0050] In addition, the predetermined distance for the sieving operation is set to a length that prevents the bucket 33 from hitting obstacles located on the opposite side of the machine body 24. If the predetermined distance for moving the arm 32 is long, there is a risk that the bucket 33 will hit an obstacle such as the side of the soil pit 70. By setting the predetermined distance to a length that prevents the bucket 33 from hitting an obstacle, the sieving operation can be performed safely.

[0051] Furthermore, if there is not a predetermined amount of soil or sand on the tip side of the bucket 33, the sifting operation is not performed. The predetermined amount is the amount that can be expected to have a leveling effect by the sifting operation. Therefore, if there is not a predetermined amount of soil or sand on the tip side of the bucket 33, a leveling effect cannot be expected, and there is little need to perform the sifting operation. In this case, not performing the sifting operation allows for an earlier transition to the next operation.

[0052] (Variation) As shown in FIGS. 5A to 5D, which are side views of the arm 32 and the bucket 33, the controller may cause the bucket 33 holding earth and sand to assume a holding position, and then perform a sieving operation. Specifically, first, as shown in FIG. 5A, the boom 31, arm 32, and bucket 33 are stopped while the bucket 33 is holding earth and sand. Next, as shown in FIG. 5B, the bucket 33 is rotated to assume the holding position. The holding position is a position in which the opening of the bucket 33 is inclined with respect to the horizontal plane so that the opening faces away from the machine body 24. Next, as shown in FIG. 5C, the bucket 33 is rotated so that the opening faces of the bucket 33 are horizontal, while the arm 32 is moved away from the machine body 24 (the arm is pushed). Next, as shown in FIG. 5D, when the arm 32 has moved a predetermined distance, the rotation of the arm 32 is stopped. At this time, the opening faces of the bucket 33 become horizontal.

[0053] By performing the sift operation after placing the bucket 33 in the holding position, the soil at the tip of the bucket 33 can be suitably moved to the back side of the bucket 33. This makes it possible to suitably level the soil that has been concentrated at the tip of the bucket 33.

[0054] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and other aspects can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferred actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention. [Explanation of symbols]

[0055] 1. Work machinery 11 Controller 13 Storage device 21 Undercarriage 22 Upper rotating body 23 Cab 24 Machine body 25 Swivel 30 Attachments 31 Boom 31a Boom foot pin 32 Arm 33 Bucket 34 Link member 40 cylinders 41 Boom cylinder 42 Arm cylinder 43 Bucket cylinder 52 Angle Sensor 55 Imaging device 60 Inclination sensor 61 Boom tilt angle sensor 62 Arm tilt angle sensor 63 Bucket tilt angle sensor 70 Earth and sand pit (excavation target)

Claims

1. The machine body, a boom attached to the machine body so as to be rotatable in the vertical direction; an arm attached to the boom so as to be rotatable in the vertical direction; a bucket pivotally attached to the arm; a controller that drives the boom, the arm, and the bucket to automatically perform a series of operations from excavating soil within an excavation target to discharging the soil to a discharge target; and the controller controls the boom, the arm, and the bucket so that after excavating earth and sand within the excavation target, a sift operation is performed and then the earth is discharged onto the earth discharge target; The sieving operation is an operation in which, from a state in which the soil and sand are held in the bucket, the arm is moved in a direction opposite to the machine body at a predetermined speed or more by a predetermined distance and then stopped; The sift operation is an operation of a work machine characterized in that, from a state in which the bucket holds soil and sand, the bucket is rotated in a direction in which the tip of the bucket approaches the machine body and the opening surface is horizontal with respect to the arm, while the arm is moved in the opposite direction from the machine body at or above the predetermined speed for the predetermined distance and then stopped.

2. The machine body, a boom attached to the machine body so as to be rotatable in the vertical direction; an arm attached to the boom so as to be rotatable in the vertical direction; a bucket pivotally attached to the arm; a controller that drives the boom, the arm, and the bucket to automatically perform a series of operations from excavating soil within an excavation target to discharging the soil to a discharge target; and the controller controls the boom, the arm, and the bucket so that after excavating earth and sand within the excavation target, a sift operation is performed and then the earth is discharged onto the earth discharge target; The sieving operation is an operation in which, from a state in which the soil and sand are held in the bucket, the arm is moved in a direction opposite to the machine body at a predetermined speed or more by a predetermined distance and then stopped; The controller causes the bucket holding the soil and sand to assume a holding position and then causes the sieving operation to be performed, The working machine is characterized in that the tucked posture is a posture in which the open face of the bucket is inclined with respect to a horizontal plane so that the open face faces away from the machine body.

3. an imaging device that images the bucket, The controller is characterized in that it causes the sieving operation to be performed when there is a predetermined amount of earth and sand on the tip side of the bucket in the image.

3. A work machine according to claim 1 or 2.

4. The machine body, a boom attached to the machine body so as to be rotatable in the vertical direction; an arm attached to the boom so as to be rotatable in the vertical direction; a bucket pivotally attached to the arm; a controller that drives the boom, the arm, and the bucket to automatically perform a series of operations from excavating soil within an excavation target to discharging the soil to a discharge target; and The controller causes a sieving operation to be performed after the soil and sand in the excavation target is excavated, Thereafter, the boom, the arm, and the bucket are controlled so as to discharge earth onto the earth discharge target, The sieving operation is an operation in which, from a state in which the soil and sand are held in the bucket, the arm is moved in a direction opposite to the machine body at a predetermined speed or more by a predetermined distance and then stopped; an imaging device that images the bucket, The controller is configured to not perform the sieving operation when there is not a predetermined amount of earth and sand on the tip side of the bucket in the image captured.

5. The controller increases or decreases the predetermined speed depending on the amount of soil and sand on the tip side of the bucket. A work machine according to claim 3 or 4.

6. the controller calculates the predetermined distance by determining a distance between the bucket and an outer periphery of the excavation target based on the image of the excavation target captured by the imaging device. A work machine according to any one of claims 3 to 5.

7. the controller calculates the predetermined distance from a distance between the bucket and an outer periphery of the excavation target. A work machine according to any one of claims 1 to 5.

8. the controller calculates the predetermined distance from a distance between the bucket and an outer periphery of the excavation target based on a size of the excavation target that has been taught in advance; 8. The work machine according to claim 7.

9. 9. The work machine according to claim 1, wherein the controller sets an angle between an opening surface of the bucket and a horizontal plane to a predetermined angle or greater when the bucket is used to scoop up earth and sand.

10. 10. The work machine according to claim 1, wherein the controller causes the bucket holding earth and sand to perform the sieving operation while the bucket is raised to a predetermined height or higher.

11. The work machine according to any one of claims 1 to 10, wherein the controller sets the predetermined distance to a length that prevents the bucket from hitting an obstacle located on the opposite side of the machine body.

Images