Construction machinery, drive systems for construction machinery, and drive units for construction machinery

Abstract

To broaden the range of operations that can be performed using construction machinery. [Solution] The excavator 10 includes a first drive unit 51 that outputs torque around a first rotation axis 51J that is perpendicular to a reference axis K extending vertically from the movable vehicle body 12, and a first boom 61 connected to the vehicle body 12 that receives torque from the first drive unit 51 and rotates around the first rotation axis 51J. When the excavator 10 is viewed in a direction parallel to the first rotation axis 51J, the first boom 61 is rotatable in both directions relative to the reference axis K.

Description

Technical Field

[0001] This invention relates to construction machinery, a drive device for construction machinery, and a drive unit for construction machinery.

Background Art

[0002] The excavator disclosed in Patent Document 1 includes a vehicle body, a boom, an arm, and a bucket. The boom is connected to the front end of the vehicle body. The boom is rotatable vertically with respect to the vehicle body. The arm is connected to the tip of the boom. The arm is rotatable vertically with respect to the boom. The bucket is connected to the tip of the arm. The bucket is rotatable vertically with respect to the arm.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology such as Patent Document 1, it is desirable to widen the working range using a series of working mechanisms including a boom.

Means for Solving the Problems

[0005] The construction machinery for solving the above problems includes a drive device that outputs torque centered on a rotation axis orthogonal to a reference axis extending vertically on a travelable vehicle body, and a boom that is connected to the vehicle body and rotates about the rotation axis upon receiving the torque from the drive device. When viewed in a direction parallel to the rotation axis, the boom is rotatable on both one side and the other side with respect to the reference axis.

[0006] In the above configuration, the boom can be extended to both one and the other side of the reference axis. Therefore, work can be performed over a wide area. In construction machinery, when viewed in a direction parallel to the axis of rotation, the boom may be rotatable by 90 degrees or more to one side and 90 degrees or more to the other side with respect to the reference axis.

[0007] In a construction machine, when the drive unit is designated as the first drive unit and the rotation axis as the first rotation axis, a second drive unit outputs torque around a second rotation axis that is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point to the vehicle body, an arm connected to the end of the boom opposite to the connection point to the vehicle body, which rotates around the second rotation axis in response to torque from the second drive unit, and a third rotation axis that is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point to the boom The apparatus comprises a third drive unit that outputs torque centered on a certain axis, and an attachment connected to the end of the arm opposite to the connection point with respect to the boom, which receives torque from the third drive unit and rotates about the third rotation axis, wherein when viewed in a direction parallel to the first rotation axis, the arm is rotatable to one side and the other side with respect to a virtual straight line connecting the first rotation axis and the second rotation axis, and the attachment may be rotatable to one side and the other side with respect to a virtual straight line connecting the second rotation axis and the third rotation axis.

[0008] In a construction machine, when viewed in a direction parallel to the axis of rotation, the vehicle body has an inclined surface that is inclined so as it moves upward, approaching the reference axis, and a top surface that is connected to the uppermost end of the inclined surface and is perpendicular to the reference axis, and the boom may be connected to the top surface.

[0009] The construction machine comprises a slewing device that outputs torque around a slewing axis parallel to the reference axis, and a connecting member interposed between the vehicle body and the boom, which receives torque from the slewing device and rotates around the slewing axis, wherein the connecting member may be rotatable over its entire circumference around the slewing axis.

[0010] In a construction machine, the vehicle body is configured in a frustoconical shape in which the cross-sectional area perpendicular to the reference axis decreases as it extends upward, and the boom may be connected to the top surface, which is the upper surface of the vehicle body.

[0011] In construction machinery, the connection point of the boom to the vehicle body may be located in the center of the vehicle body in a direction perpendicular to both the rotation axis and the reference axis. In a construction machine, when the drive unit is designated as a first drive unit and the rotation axis as a first rotation axis, the machine comprises: a second drive unit that outputs torque around a second rotation axis which is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point with the vehicle body; an arm connected to the end of the boom opposite to the connection point with the vehicle body and rotating around the second rotation axis in response to torque from the second drive unit; a third drive unit that outputs torque around a third rotation axis which is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point with the boom; and an attachment connected to the end of the arm opposite to the connection point with the boom and rotating around the third rotation axis in response to torque from the third drive unit, wherein the attachment has two buckets having openings, the openings of the two buckets facing in opposite directions and aligned in the circumferential direction around the third rotation axis.

[0012] In a construction machine, the bucket has a box-shaped bucket body with an opening and a claw protruding from the opening edge of the bucket body, and when viewed in a direction parallel to the third axis of rotation, in each bucket, the claw protrudes from the position on the opening edge of the bucket body furthest from the third axis of rotation, and when viewed in a direction parallel to the third axis of rotation, the rotational trajectory of the protruding end of the claw in one bucket and the rotational trajectory of the protruding end of the claw in the other bucket may overlap when the attachment rotates once around the third axis of rotation while the arm is in a fixed position.

[0013] In a construction machine, when the drive device is designated as a first drive device and the rotation axis as a first rotation axis, the machine includes: a second drive device that outputs torque around a second rotation axis which is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point with the vehicle body; an arm connected to the end of the boom opposite to the connection point with the vehicle body and rotating around the second rotation axis in response to torque from the second drive device; a third drive device that outputs torque around a third rotation axis which is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point with the boom; and an attachment connected to the end of the arm opposite to the connection point with the boom and rotating around the third rotation axis in response to torque from the third drive device, wherein when viewed in a direction parallel to the first rotation axis, the arm may be rotatable to the extent that the third rotation axis is located on a half-line extending from the second rotation axis and intersecting the first rotation axis.

[0014] In a construction machine, when the drive unit is designated as the first drive unit and the rotation axis as the first rotation axis, a second drive unit outputs torque around a second rotation axis that is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point to the vehicle body; an arm connected to the end of the boom opposite to the connection point to the vehicle body and rotates around the second rotation axis in response to torque from the second drive unit; a third drive unit outputs torque around a third rotation axis that is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point to the boom; an attachment connected to the end of the arm opposite to the connection point to the boom and rotates around the third rotation axis in response to torque from the third drive unit; and a control system for the first drive unit, the second drive unit, and the third drive unit. The device comprises a control device, the control device being capable of switching between a first posture in which, when viewed in a direction parallel to the first rotation axis, the boom is rotated to one side with respect to the reference axis, and the third rotation axis is located on the opposite side of the second rotation axis from the first rotation axis in a direction perpendicular to both the first rotation axis and the reference axis, and a second posture in which, when viewed in a direction parallel to the first rotation axis, the boom is rotated to the other side with respect to the reference axis, and the third rotation axis is located on the opposite side of the second rotation axis from the first rotation axis in a direction perpendicular to both the first rotation axis and the reference axis, and when switching between the first posture and the second posture, the arm may be rotated across a half-line extending from the second rotation axis and intersecting the first rotation axis when viewed in a direction parallel to the first rotation axis.

[0015] A construction machine for solving the above problems comprises: a first slewing device that outputs torque around a first slewing axis extending vertically above and below a drivable vehicle body; a boom connected to the vehicle body and rotating around the first slewing axis in response to torque from the first slewing device; a second slewing device that outputs torque around a second slewing axis parallel to the first slewing axis and passing through the end of the boom opposite to the connection point to the vehicle body; an arm connected to the end of the boom opposite to the connection point to the vehicle body and rotating around the second slewing axis in response to torque from the second slewing device; and an attachment connected to the end of the arm opposite to the connection point to the boom.

[0016] In the above configuration, the boom and arm can move over a wide area on a plane perpendicular to the first pivot axis. With this configuration, work can be performed over a wide area. In construction machinery, the attachment may be an electrically operated telescopic device that extends and retracts in a direction along an operating axis parallel to the first pivot axis.

[0017] A construction machine to solve the above problems includes: a first drive unit that outputs torque around a first rotation axis perpendicular to a reference axis extending vertically from the drivable vehicle body; a boom connected to the vehicle body that rotates around the first rotation axis in response to torque from the first drive unit; a second drive unit that outputs torque around a second rotation axis parallel to the first rotation axis and passing through the end of the boom opposite to the connection point to the vehicle body; and a boom connected to the end of the boom opposite to the connection point to the vehicle body that rotates around the second rotation axis in response to torque from the second drive unit. The device comprises a rotating arm and an attachment connected to the end of the arm opposite to the connection point with the boom. When the first drive unit, the boom, the second drive unit, the arm, and the attachment are combined to form one working mechanism, there are two sets of the working mechanisms. When viewed in a direction parallel to the first rotation axis of a specific working mechanism among the two sets of the working mechanisms, the two sets of the working mechanisms are located on one side and the other side of the center of the vehicle body in a direction perpendicular to both the first rotation axis and the reference axis for the specific working mechanism.

[0018] In the above configuration, the work mechanisms are located on both sides of the vehicle's center. Therefore, work can be performed on both sides of the vehicle's center. With this configuration, work can be performed over a wide area.

[0019] A drive system for construction machinery that solves the above problems is capable of outputting torque around a rotation axis that is perpendicular to a reference axis extending vertically above the drivable vehicle body, to a boom that is rotatably connected to the vehicle body, and when viewed in a direction parallel to the rotation axis, the boom can be rotated in both directions relative to the reference axis.

[0020] In the above configuration, the boom can be extended to both one and the other side of the reference axis. Therefore, work can be performed over a wide area. The drive unit of the construction machine may be capable of rotating the boom by 90 degrees or more to one side and 90 degrees or more to the other side with respect to the reference axis when viewed in a direction parallel to the rotation axis.

[0021] The drive unit for construction machinery to solve the above problems includes: a first drive unit capable of outputting torque around the first rotation axis to a boom that is rotatably connected to the vehicle body so as to a first rotation axis perpendicular to a reference axis extending vertically up and down the vehicle body; a second drive unit capable of outputting torque around the second rotation axis to an arm that is connected to the end of the boom opposite to the connection point to the vehicle body, passes through that end and is rotatable around a second rotation axis parallel to the first rotation axis; and a second drive unit connected to the end of the arm opposite to the connection point to the boom, passes through that end and is parallel to the first rotation axis. The device comprises an attachment rotatable about a third rotation axis parallel to a first rotation axis, and a third drive unit capable of outputting torque about the third rotation axis, wherein when viewed in a direction parallel to the first rotation axis, the first drive unit can rotate the boom in both directions with respect to the reference axis, the second drive unit can rotate the arm in both directions with respect to a virtual straight line connecting the first rotation axis and the second rotation axis, and the third drive unit can rotate the attachment in both directions with respect to a virtual straight line connecting the second rotation axis and the third rotation axis.

[0022] In the above configuration, the boom can be extended to both one and the other side of the reference axis. Furthermore, in this configuration, the arm can be rotated relative to the boom, and the attachment can be rotated relative to the arm, regardless of whether the boom is positioned on one or the other side of the reference line. Through these movements of the boom, arm, and attachment, the attachment can be moved to various positions. Therefore, work can be performed over a wide area.

[0023] The drive unit of a construction machine for solving the above problems is capable of outputting torque about a rotational axis that is orthogonal to a reference axis extending vertically above and below a travelable vehicle body, and is connected to a boom that is rotatably connected to the vehicle body about the rotational axis. When viewed in a direction facing a direction parallel to the rotational axis, the drive unit includes a drive device that can rotationally drive the boom on both sides, i.e., one side and the other side, with respect to the reference axis, and a connecting member that is interposed between the vehicle body and the boom and is rotatable about a swivel axis parallel to the reference axis. The drive unit is capable of outputting torque about the swivel axis and can rotationally drive the connecting member over a full circle about the swivel axis.

[0024] In the above configuration, the boom can be moved to both sides, i.e., one side and the other side, with respect to the reference axis. Further, in the above configuration, the boom can be moved to various positions on a plane orthogonal to the reference axis. Therefore, work can be performed over a wide range.

[0025] The drive unit of a construction machine for solving the above problems includes a first swivel device that outputs torque about a first swivel axis that is rotatably connected to a boom that is rotatably connected to a travelable vehicle body about the first swivel axis extending vertically above and below the vehicle body, and a second swivel device that outputs torque about a second swivel axis. The second swivel device is connected to an end portion of the boom opposite to the connection portion of the boom to the vehicle body and is rotatable about the second swivel axis that passes through the end portion and is parallel to the first swivel axis.

[0026] In the above configuration, the boom and the arm can be widely moved on a plane orthogonal to the first swivel axis. Therefore, work can be performed over a wide range.

Effects of the Invention

[0027] With the above technical idea, the working range of a construction machine can be widened.

Brief Description of the Drawings

[0028] [Figure 1] Figure 1 is a schematic top view showing the general configuration of an excavator. [Figure 2] Figure 2 is a schematic side view showing the general configuration of an excavator. [Figure 3] Figure 3 is a schematic side view illustrating the general configuration of an excavator. [Figure 4] Figure 4 shows the rotational trajectories of the first and second buckets. [Figure 5] Figure 5 is a schematic representation of the second work tool. [Figure 6] Figure 6 is a schematic side view illustrating an example of how an excavator is used. [Figure 7] Figure 7 is a schematic top view illustrating an example of how an excavator is used. [Figure 8] Figure 8 is a schematic side view illustrating an example of a modified excavator. [Figure 9] Figure 9 is a schematic side view illustrating an example of the excavator shown in Figure 8 in use. [Figure 10] Figure 10 is a top view relating to the usage state shown in Figure 9. [Figure 11] Figure 11 is a schematic diagram illustrating an example of a modification to the first mechanism in the excavator shown in Figure 8. [Figure 12] Figure 12 is a schematic side view illustrating an example of a modified excavator. [Figure 13] Figure 13 is a schematic side view illustrating an example of the excavator shown in Figure 12 in use. [Figure 14] Figure 14 is a schematic top view showing an example of the arrangement of the first and second working mechanisms. [Figure 15] Figure 15 is a schematic side view illustrating an example of a modified excavator. [Modes for carrying out the invention]

[0029] <Overall Structure> Hereinafter, an embodiment of a construction machine, a drive system for a construction machine, and a drive unit for a construction machine will be described with reference to the drawings. Note that the drawings may show components enlarged for ease of understanding. Also, the dimensional ratios of the components may differ from those of the actual components or those shown in other drawings. In this embodiment, "parallel" includes both cases where two straight lines extend without intersecting at different positions and cases where two straight lines coincide perfectly.

[0030] As shown in Figure 1, the excavator 10, a construction machine, comprises a body 12 and a pair of running gears 16. As shown in Figure 2, the body 12 comprises a lower body 14 and an upper body 20. The upper body 20 is located on the opposite side of the ground G from the lower body 14. In this embodiment, the up, down, front, back, left, and right directions of the excavator 10 are defined with respect to the body 12. That is, the direction in which the upper body 20 is located when viewed from the lower body 14 is the up direction, and the opposite direction is the down direction. In addition, a specific direction perpendicular to the up direction is the forward direction, and the opposite direction is the rear direction. Furthermore, one of the directions perpendicular to both the up direction and the forward direction is the left direction, and the other is the right direction. Hereinafter, the forward and rear directions may be collectively referred to as the X direction. The left and right directions may be collectively referred to as the Y direction. The up and down directions may be collectively referred to as the Z direction.

[0031] As shown in Figure 1, a pair of running gears 16 are located on both the left and right sides of the lower body 14. The running gears 16 include crawler tracks for travel and an operating mechanism for rotating the crawler tracks. As shown by the dashed line of reference numeral 16 in Figure 2, the crawler tracks are in the shape of an endless belt. The crawler tracks extend in the X direction and open on both the left and right sides. The underside of the crawler tracks is in contact with the ground G. As the crawler tracks rotate, the excavator 10 and, consequently, the vehicle body 12 move. In other words, the vehicle body 12 is capable of travel.

[0032] As shown in Figure 2, the lower body 14 is, for example, rectangular. The lower body 14 houses various mechanisms, devices, and parts necessary for operating the excavator 10. The upper body 20 is frustoconical in shape. The central axis of the upper body 20 is referred to as the reference axis K. The reference axis K extends approximately in the Z direction. That is, the reference axis K approximately coincides with the vertical axis of the excavator 10 and, consequently, the vehicle body 12, and extends vertically above and below the vehicle body 12. In this embodiment, the reference axis K passes through the geometric center of the lower body 14 when viewed from the upper body 20 side. Furthermore, the reference axis K is approximately perpendicular to a horizontal plane that is virtually extended from the ground G to which the lower surface of the crawler of the running gear 16 is in contact. Due to the shape of the upper body 20, the cross-sectional area perpendicular to the reference axis K becomes smaller as it extends upwards. The upper body 20 is hollow. That is, the inside of the upper body 20 is a storage space.

[0033] The upper body 20 comprises a top surface 23, a bottom surface 21, and a side surface 22. The bottom surface 21 is the downward-facing surface of the upper body 20. The bottom surface 21 is circular. The bottom surface 21 is approximately perpendicular to the reference axis K. The side surface 22 rises from the bottom surface 21. The specific axis perpendicular to the reference axis K is called the first rotation axis 51J. Viewing the excavator 10 in a plan view in a direction parallel to the first rotation axis 51J is called a specific plan view. As shown in Figure 2, in the specific plan view, the side surface 22 is inclined so that it approaches the reference axis K as it goes upwards. In other words, the side surface 22 is an inclined surface. The top surface 23 is the upward-facing surface of the upper body 20. The top surface 23 is circular. The top surface 23 connects to the entire uppermost end of the side surface 22. The top surface 23 is approximately perpendicular to the reference axis K. In a specific planar view, the inferior angle θ between the top surface 23 and the side surface 22 is approximately 120 degrees. The inferior angle θ is the angle between the top surface 23 and the side surface 22 that is smaller than 180 degrees. Note that the magnitude of the inferior angle θ shown in Figure 2 is for convenience only. Although not shown in the illustration, an opening is provided near the center of the top surface 23 that connects the inside and outside of the upper body 20.

[0034] <Main slewing mechanism> As shown in Figure 2, the excavator 10 is equipped with a main slewing device 30. The main slewing device 30 is located inside the upper body 20. The main slewing device 30 is cylindrical in shape as a whole. The central axis of the main slewing device 30 extends approximately in the Z direction. The main slewing device 30 comprises a main body 30A and an output member 30B. For convenience, the main body 30A and the output member 30B are shown separated by a dotted line in the drawing. This is also the case for other slewing devices described later.

[0035] The outer casing of the main body 30A is fixed to the inner wall of the upper body 20. The main body 30A includes an electric motor and a reduction gear. The electric motor is the drive source for the main slewing device 30. The electric motor receives power from a battery (not shown). Depending on the power supply to the electric motor, the output shaft of the electric motor can output torque in both forward and reverse directions. The reduction gear amplifies the torque output by the output shaft of the electric motor at a predetermined ratio and outputs it to the output member 30B. The reduction gear can be, for example, an eccentric oscillating gear type or a planetary gear type. The reduction gear can be of any type as long as it is configured to amplify and output the torque from the electric motor. The output member 30B is rotatable relative to the outer casing of the main body 30A.

[0036] The output member 30B rotates around the main pivot axis 30J by receiving torque from the reduction gear. The main pivot axis 30J extends approximately in the Z direction. In this embodiment, the main pivot axis 30J approximately coincides with the reference axis K. The output member 30B, and thus the main pivot device 30, outputs torque around this main pivot axis 30J. The output member 30B is rotatable over its entire circumference in both forward and reverse directions according to the rotation direction of the electric motor. A portion of the upper part of the output member 30B protrudes upward from the top surface 23 of the upper body 20 through an opening in the top surface 23.

[0037] <Connecting members> As shown in Figure 2, the excavator 10 is equipped with a connecting member 25. The connecting member 25 is located on the upward side relative to the top surface 23 of the upper body 20. As shown in Figure 1, the connecting member 25 is disc-shaped. The diameter of the circle of the connecting member 25 is slightly smaller than the diameter of the top surface 23. The center of the circle of the connecting member 25 is located on the reference axis K. As shown in Figure 2, the lower surface of the connecting member 25 faces the top surface 23. The lower surface of the connecting member 25 is fixed to the output member 30B of the main slewing device 30. The connecting member 25 rotates integrally with the output member 30B of the main slewing device 30. That is, the connecting member 25 rotates around the main slewing axis 30J by receiving torque from the main slewing device 30. In relation to the rotation range of the output member 30B of the main slewing axis 30J, the connecting member 25 can rotate around the entire circumference of the main slewing axis 30J. In other words, the main slewing device 30 is capable of outputting torque to the connecting member 25 around the main slewing axis 30J. The main slewing device 30 is also capable of rotating the connecting member 25 around the entire circumference of the main slewing axis 30J. Although not shown in the figures, a bearing is positioned between the exposed area of ​​the lower surface of the connecting member 25, which is the area away from the output member 30B of the main slewing device 30, and the top surface 23 of the upper body 20, to support the connecting member 25 so that it can rotate relative to the top surface 23.

[0038] <Supporting wall> As shown in Figure 2, the excavator 10 is equipped with a support wall 27. The support wall 27 protrudes upward from the upper surface of the connecting member 25. The support wall 27 is rectangular in shape. The support wall 27 is fixed to the upper surface of the connecting member 25. The support wall 27 straddles the center of the upper body 20 in a direction perpendicular to both the reference axis K and the first rotation axis 51J.

[0039] <First mechanism> As shown in Figures 1 and 2, the excavator 10 is equipped with a first mechanism 41. The first mechanism 41 comprises a first drive unit 51, a second drive unit 52, a third drive unit 53, a first boom 61, a first arm 62, and a first attachment 63. Note that the second mechanism 42, which will be described later, is not shown in Figure 2. Also, Figure 2 shows a usage state in which both the first boom 61 and the first arm 62 extend linearly upward, which is different from the usage state in Figure 1.

[0040] <First drive unit> As shown in Figure 1, the first drive unit 51 is located next to the support wall 27. The first drive unit 51 comprises a main body 51A and a first output member 51B. For convenience, the main body 51A and the first output member 51B are shown separated by a dotted line in the drawing. This is also the case for the other drive units.

[0041] The outer casing of the main body 51A is fixed to the side of the support wall 27. The main body 51A includes an electric motor and a reduction gear. The electric motor is the power source of the first drive unit 51. The electric motor receives power from a battery (not shown). Depending on the power supply to the electric motor, the output shaft of the electric motor can output torque in both forward and reverse directions. The reduction gear amplifies the torque output by the output shaft of the electric motor at a predetermined ratio and outputs it to the first output member 51B. The reduction gear may be, for example, an eccentric oscillating gear type or a planetary gear type. The reduction gear can be of any type as long as it is configured to amplify and output the torque from the electric motor.

[0042] The first output member 51B is rotatable relative to the outer casing of the main body 51A. The first output member 51B rotates around the first rotation axis 51J in response to torque from the reduction gear. As described above, the first rotation axis 51J is a specific axis that is substantially perpendicular to the reference axis K. The first output member 51B, and thus the first drive unit 51, outputs torque around this first rotation axis 51J. The first output member 51B is rotatable over its entire circumference in both forward and reverse directions, depending on the rotation direction of the electric motor. The first drive unit 51, together with the main slewing device 30, constitutes a specific drive unit.

[0043] <First boom> As shown in Figure 1, the first boom 61 is located on the opposite side of the support wall 27 from the first drive unit 51. The first boom 61 is a long, plate-like or columnar shape. In this embodiment, the first boom 61 extends in a straight line. The first longitudinal end 61A of the first boom 61 is positioned where the first rotation axis 51J passes through. The first output member 51B of the first drive unit 51 is fixed to the first end 61A of the first boom 61. The first boom 61 rotates integrally with the first output member 51B. That is, the first boom 61 rotates about the first rotation axis 51J in response to torque from the first drive unit 51. In other words, the first drive unit 51 outputs torque to the first boom 61 about the first rotation axis 51J.

[0044] As described above, the first end 61A of the first boom 61 is connected to the support wall 27 via the first drive unit 51. Then, as shown in Figure 2, the support wall 27 is connected to the top surface 23 of the upper body 20 via the connecting member 25 and the main slewing device 30. In other words, the first end 61A of the first boom 61 is connected to the top surface 23 of the upper body 20 via the first drive unit 51, the support wall 27, the connecting member 25, and the main slewing device 30. Therefore, the first end 61A of the first boom 61 corresponds to the connection point between the first boom 61 and the upper body 20. In consideration of the arrangement of the support wall 27 relative to the upper body 20 as described above, the first end 61A of the first boom 61 is located approximately in the center of the upper body 20 in a direction perpendicular to both the reference axis K and the first rotation axis 51J. Furthermore, as a result of the above-described connection configuration, the support wall 27 and the connecting member 25 are interposed between the first boom 61 and the top surface 23 of the upper body 20.

[0045] As described above, the first boom 61 rotates about the first rotation axis 51J. The angular range of this rotation will be explained with reference to Figure 2. As described above, the angle θ between the top surface 23 and the side surface 22 of the upper body 20 is approximately 120 degrees. Also, as described above, the first output member 51B of the first drive unit 51 is rotatable around the entire circumference in both forward and reverse directions about the first rotation axis 51J, which is approximately perpendicular to the reference axis K. The first rotation axis 51J passes near the top surface 23. In relation to the positional relationship between the first rotation axis 51J and the top surface 23, and the magnitude of the angle θ between the top surface 23 and the side surface 22, the first boom 61 is rotatable within the following rotation range in a specific planar view. The first boom 61 is rotatable to one side and the other side with respect to the reference axis K. More specifically, in a specific plan view, the first boom 61 is rotatable to one side and the other side, straddling a reference half-line that extends from the first rotation axis 51J on the reference axis K toward the opposite side from the top surface 23. More specifically, the first boom 61 is rotatable to one side with respect to the reference half-line up to a first rotation angle, and is also rotatable to the other side with respect to the reference half-line up to a first rotation angle. The first rotation angle is approximately 150 degrees. In other words, in a specific plan view, the first drive device 51 is capable of driving the first boom 61 to rotate both to one side and the other side with respect to the reference axis K. More specifically, the first drive device 51 is capable of driving the first boom 61 to rotate to one side with respect to the reference half-line up to a first rotation angle. Furthermore, the first drive device 51 is capable of driving the first boom 61 to rotate to the other side with respect to the reference half-line up to a first rotation angle. A half-line is a straight line that extends only in one direction from a specific point.

[0046] Assuming a specific planar view, the following can be said regarding the rotation of the first boom 61. The imaginary straight line connecting the first end 61A of the first boom 61 and the second end 61B, which is the end opposite to the first end 61A, is called the first imaginary straight line 41E. In this embodiment, this first imaginary straight line 41E corresponds to the imaginary straight line connecting the first rotation axis 51J and the second rotation axis 52J, which will be described later. When the first boom 61 rotates to one side with respect to the reference axis K, it means that the first imaginary straight line 41E rotates to one side with respect to the reference axis K, with respect to the first rotation axis 51J as the center. Similarly, when the first boom 61 rotates to the other side with respect to the reference axis K, it means that the first imaginary straight line 41E rotates to the other side with respect to the reference axis K, with respect to the first rotation axis 51J as the center.

[0047] <Second drive unit> As shown in Figure 1, the second drive unit 52 is located near the second end 61B of the first boom 61. In a direction parallel to the first rotation axis 51J, the second drive unit 52 is located on the opposite side of the first boom 61 from the first drive unit 51. The second drive unit 52 is configured similarly to the first drive unit 51. That is, the second drive unit 52 comprises a main body 52A having a reduction gear in addition to an electric motor which is the drive source, and a second output member 52B that rotates by receiving torque from the main body 52A. The outer casing of the main body 52A is fixed to the second end 61B of the first boom 61. The second output member 52B rotates about the second rotation axis 52J by receiving torque from the reduction gear in the main body 52A. The second rotation axis 52J extends approximately parallel to the first rotation axis 51J at a different position from the first rotation axis 51J. The second rotation axis 52J passes through the second end 61B of the first boom 61. The second output member 52B and, consequently, the second drive unit 52, output torque centered on this second rotation axis 52J. The second output member 52B is rotatable over its entire circumference in both forward and reverse directions, depending on the rotation direction of the electric motor.

[0048] <First Arm> As shown in Figure 1, the first arm 62 is located next to the second drive unit 52. In a direction parallel to the first rotation axis 51J, the first arm 62 is located on the opposite side of the second drive unit 52 from the first boom 61. The first arm 62 is a long, plate-like or columnar shape. In this embodiment, the first arm 62 extends in a straight line. The first longitudinal end 62A of the first arm 62 is positioned where the second rotation axis 52J passes through. The first end 62A of the first arm 62 is fixed to the second output member 52B of the second drive unit 52. The first end 62A of the first arm 62 rotates integrally with the second output member 52B. That is, the first arm 62 rotates about the second rotation axis 52J in response to torque from the second drive unit 52. In other words, the second drive unit 52 outputs torque to the first arm 62 about the second rotation axis 52J. Thus, the first end 62A of the first arm 62 is connected to the second drive unit 52. At the same time, the first end 62A of the first arm 62 is connected to the second end 61B of the first boom 61 via the second drive unit 52. In other words, the first end 62A of the first arm 62 corresponds to the connection point with the first boom 61.

[0049] As described above, the first arm 62 rotates in response to torque from the second drive unit 52. The second output member 52B of the second drive unit 52 is rotatable around the entire circumference in both forward and reverse directions about the second rotation axis 52J. Therefore, in the specific plan view shown in Figure 2, the first arm 62 is rotatable on both sides of the first virtual straight line 41E connecting the first rotation axis 51J and the second rotation axis 52J. In detail, the first arm 62 of this embodiment is rotatable on both sides of the first virtual straight line 41E, crossing a first virtual half-line that extends from the second rotation axis 52J in the direction opposite to the first rotation axis 51J, in conjunction with the arrangement of the first attachment 63, which will be described later. More specifically, the first arm 62 is rotatable to one side of the first virtual half-line up to a second rotation angle, and also rotatable to the other side of the first virtual half-line up to a second rotation angle. The second rotation angle is approximately 180 degrees. In other words, in a specific plan view, the second drive device 52 can rotate the first arm 62 both to one side and to the other side of the first virtual half-line. More specifically, the second drive device 52 can rotate the first arm 62 to one side of the first virtual half-line up to a second rotation angle. Furthermore, the second drive device 52 can rotate the first arm 62 to the other side of the first virtual half-line up to a second rotation angle.

[0050] Similar to the case of the first boom 61, assuming a specific planar view, the following can be said about the rotation of the first arm 62. The imaginary line connecting the first end 62A of the first arm 62 and the second end 62B, which is the end opposite to the first end 62A, is called the second imaginary line 41F. In this embodiment, this second imaginary line 41F corresponds to the imaginary line connecting the second rotation axis 52J and the third rotation axis 53J, which will be described later. Rotation of the first arm 62 to one side with respect to the first imaginary line 41E means that the second imaginary line 41F rotates to one side with respect to the first imaginary line 41E about the second rotation axis 52J. Similarly, rotation to the other side means that the second imaginary line 41F rotates to the other side with respect to the first imaginary line 41E about the second rotation axis 52J.

[0051] <Third drive unit> As shown in Figure 1, the third drive unit 53 is located near the second end 62B of the first arm 62. In a direction parallel to the first rotation axis 51J, the third drive unit 53 is located in approximately the same position as the second drive unit 52. The third drive unit 53 is configured similarly to the first drive unit 51 and the second drive unit 52. That is, the third drive unit 53 comprises a main body 53A having a reduction gear in addition to an electric motor which is the drive source, and a third output member 53B that rotates by receiving torque from the main body 53A. The outer casing of the main body 53A is fixed to the second end 61B of the first arm 62. The third output member 53B rotates about the third rotation axis 53J by receiving torque from the reduction gear in the main body 53A. The third rotation axis 53J is located at a different position from the first rotation axis 51J and the second rotation axis 52J, and extends approximately parallel to the first rotation axis 51J. The third rotation axis 53J passes through the second end 61B of the first arm 62. The third output member 53B and, consequently, the third drive unit 53, output torque centered on this third rotation axis 53J. The third output member 53B is rotatable over its entire circumference in both forward and reverse directions, depending on the rotation direction of the electric motor. The third drive unit 53, together with the first drive unit 51 and the second drive unit 52, constitutes the first drive unit.

[0052] <First Attachment> As shown in Figure 1, the first attachment 63 is located near the second end 62B of the first arm 62. The first attachment 63 comprises a first work tool 65 and a connecting piece 64.

[0053] As shown in Figures 1 and 2, the connecting piece 64 is plate-shaped and generally rectangular. As shown in Figure 1, the connecting piece 64 is positioned where the third rotation axis 53J passes through. In a direction parallel to the first rotation axis 51J, the connecting piece 64 is located on the opposite side of the third drive unit 53 from the second end 62B of the first arm 62. The main surface of the connecting piece 64 faces the third output member 53B of the third drive unit 53. The main surface of the connecting piece 64 is fixed to the third output member 53B. The main surface is the largest surface area of ​​the outer surface of the plate-shaped object. The connecting piece 64 rotates integrally with the third output member 53B. That is, the connecting piece 64 and, by extension, the first attachment 63, receive torque from the third drive unit 53 and rotate about the third rotation axis 53J. In other words, the third drive unit 53 outputs torque to the first attachment 63 centered on the third rotation axis 53J. Thus, the first attachment 63 is connected to the third drive unit 53. At the same time, the first attachment 63 is connected to the second end 62B of the first arm 62 via the third drive unit 53.

[0054] As described above, the connecting piece 64 rotates in response to torque from the third drive unit 53. The third output member 53B of the third drive unit 53 is rotatable around the third rotation axis 53J in both forward and reverse directions. Therefore, in the specific plan view shown in Figure 2, the first attachment 63 is rotatable in both directions relative to the second virtual straight line 41F connecting the second rotation axis 52J and the third rotation axis 53J. The first attachment 63 of this embodiment is rotatable approximately 360 degrees in one direction relative to the second virtual straight line 41F, and is rotatable approximately 360 degrees in the other direction relative to the second virtual straight line 41F. In other words, the first attachment 63 of this embodiment can achieve the following rotational movements. In a specific plan view, the first attachment 63 is rotatable on the second virtual line 41F, straddling a first half-line that extends from the third rotation axis 53J toward the opposite side of the second rotation axis 52J. Also, in a specific plan view, the first attachment 63 is rotatable on the second virtual line 41F, straddling a second half-line that extends from the third rotation axis 53J toward the second rotation axis 52J. In other words, in a specific plan view, the third drive device 53 can rotate the first attachment 63 on both sides, straddling the first half-line. Also, in a specific plan view, the third drive device 53 can rotate the first attachment 63 on both sides, straddling the second half-line.

[0055] Assuming a specific planar view, the following can be said regarding the rotation of the first attachment 63. As shown in Figure 2, the virtual straight line connecting the connection point between the connecting piece 64 and the first arm 62 and a specific point on the first work tool 65 is called the attachment straight line 41H. In this embodiment, the connection point between the connecting piece 64 and the first arm 62 is the point on the connecting piece 64 where the third drive device 53 is fixed, and can be treated as the third rotation axis 53J. In this embodiment, the specific point on the first work tool 65 is the corner between the first side wall 67B and the bottom wall 67D of the first bucket 65A, which will be described later. The rotation of the first attachment 63 to one side with respect to the second virtual straight line 41F means that the attachment straight line 41H rotates to one side with respect to the second virtual straight line 41F around the third rotation axis 53J. Similarly, rotation to the other side means that the attachment line 41H rotates to the other side with respect to the second virtual line 41F, around the third rotation axis 53J.

[0056] As shown in Figure 2, the first work tool 65 comprises a first bucket 65A and a second bucket 65B. The configurations of the first bucket 65A and the second bucket 65B are identical. Therefore, the first bucket 65A will be described below, and redundant explanations of the second bucket 65B will be omitted.

[0057] As shown in Figures 1 and 2, the first bucket 65A comprises a bucket body 67 and a plurality of claws 68. The bucket body 67 is box-shaped. That is, the bucket body 67 comprises a rectangular bottom wall 67D, side walls rising from each of the four sides of the bottom wall 67D, and an opening 67A enclosed by the end of each side wall opposite to the bottom wall 67D. In other words, the end of each side wall opposite to the bottom wall 67D forms a rectangular opening edge. The outer surface of the first side wall 67B, which is one of the four side walls, is fixed to the surface of the connecting piece 64 that corresponds to its thickness.

[0058] As shown in Figure 1, there are four claws 68 in this embodiment. However, the number of claws 68 is not limited to four. The claws 68 protrude from a specific side 67C among the four sides of the rectangular opening edge. The specific side 67C corresponds to the edge of the side wall opposite the first side wall 67B. In consideration of the fact that the first side wall 67B is fixed to the connecting piece 64, as shown in Figure 2, in a specific plan view, the specific side 67C is located at the position furthest from the third rotation axis 53J among the opening edge of the bucket body 67. The claws 68 then protrude from this specific side 67C toward the opposite side of the bottom wall 67D relative to the opening 67A. As shown in Figure 1, multiple claws 68 are arranged along the specific side 67C.

[0059] The positional relationship between the first bucket 65A and the second bucket 65B will now be explained. In the specific plan view shown in Figure 2, the first bucket 65A and the second bucket 65B are arranged symmetrically with respect to a specific virtual straight line, the attachment line 41H. Specifically, the outer surfaces of the bottom walls 67D of the first bucket 65A and the second bucket 65B face each other. Furthermore, the bottom walls 67D of the first bucket 65A and the second bucket 65B are fixed to each other. As a result, the openings 67A of the first bucket 65A and the openings 67A of the second bucket 65B face in opposite directions. In this state, the first bucket 65A and the second bucket 65B are aligned in the circumferential direction around the third rotation axis 53J. In addition, the first bucket 65A and the second bucket 65B are arranged in a specific plan view to satisfy the following first condition. The first condition is that the distance from the third rotation axis 53J to the protruding end of the claw 68 in the first bucket 65A is the same as the distance from the third rotation axis 53J to the protruding end of the claw 68 in the second bucket 65B. As a result of this first condition being met, the first attachment 63 has the following configuration in a specific plan view. Now, assume that the first arm 62 is maintained in a specific rotation position. Under these circumstances, assume that the first attachment 63 has rotated once around the third rotation axis 53J relative to the first arm 62. At this time, as shown by the dashed line 68Q in Figure 4, the rotation trajectory of the protruding end of the claw 68 in the first bucket 65A and the rotation trajectory of the protruding end of the claw 68 in the second bucket 65B overlap.

[0060] <Second mechanism> As shown in Figures 1 and 3, the excavator 10 is equipped with a second mechanism 42. The second mechanism 42 comprises a first slewing device 31, a second slewing device 32, a second boom 71, a second arm 72, and a second attachment 73. Note that the first mechanism 41 and the support wall 27 are not shown in Figure 3.

[0061] <First Rotating Device> As shown in Figure 3, the first slewing device 31 is located on the upper surface of the connecting member 25. As shown in Figure 1, the first slewing device 31 is located on the opposite side of the support wall 27 from the first drive device 51. The first slewing device 31 is located approximately in the center of the upper body 20 in a direction perpendicular to both the first rotation axis 51J and the reference axis K. In this embodiment, in consideration of the position of the first rotation axis 51J, when the excavator 10 is viewed in plan in a direction parallel to the reference axis K, the first slewing device 31 is positioned to coincide with the first rotation axis 51J.

[0062] As shown in Figure 3, the first slewing device 31 is cylindrical in shape overall. The first slewing device 31 comprises a main body 31A and a first slewing member 31B. The outer casing of the main body 31A is fixed to the upper surface of the connecting member 25. The main body 31A includes an electric motor and a reduction gear. The electric motor is the drive source for the first slewing device 31. The electric motor receives power from a battery (not shown). Depending on the power supply to the electric motor, the output shaft of the electric motor can output torque in both forward and reverse directions. The reduction gear amplifies the torque output by the output shaft of the electric motor at a predetermined ratio and outputs it to the first slewing member 31B. The first slewing member 31B is rotatable relative to the outer casing of the main body 31A. The first slewing member 31B rotates about the first slewing axis 31J by receiving torque from the reduction gear. In this embodiment, the first pivot axis 31J extends approximately parallel to the reference axis K at a position different from that of the reference axis K. That is, the first pivot axis 31J extends vertically above and below the vehicle body 12. The first pivot member 31B and, consequently, the first pivot device 31, output torque centered on the first pivot axis 31J. The first pivot member 31B is rotatable over its entire circumference in both forward and reverse directions according to the rotation direction of the electric motor. As shown in Figure 1, in consideration of its arrangement with the first pivot device 31, when the excavator 10 is viewed from above in a direction parallel to the reference axis K, the first pivot axis 31J is located on the first rotation axis 51J.

[0063] <Second Boom> As shown in Figure 3, the second boom 71 is located above the first slewing device 31. The second boom 71 is a long, plate-like or columnar shape. In this embodiment, the second boom 71 extends in a straight line. The first longitudinal end 71A of the second boom 71 is positioned where the first slewing axis 31J passes through. The first slewing member 31B of the first slewing device 31 is fixed to the first end 71A of the second boom 71. The second boom 71 rotates integrally with the first slewing member 31B. That is, the second boom 71 rotates around the first slewing axis 31J in response to torque from the first slewing device 31. In other words, the first slewing device 31 outputs torque to the second boom 71 around the first slewing axis 31J.

[0064] As described above, the first end 71A of the second boom 71 is connected to the connecting member 25 via the first slewing device 31. In other words, the first end 71A of the second boom 71 is connected to the top surface 23 of the upper body 20 via the first slewing device 31, the connecting member 25, and the main slewing device 30. Therefore, the first end 71A of the second boom 71 corresponds to the connection point between the second boom 71 and the upper body 20.

[0065] As described above, the second boom 71 rotates in response to torque from the first slewing device 31. The first slewing member 31B of the first slewing device 31 is rotatable around the entire circumference in both forward and reverse directions about the first slewing axis 31J. Therefore, as shown in Figure 1, the second boom 71 can rotate over a wide area without interfering with the support wall 27 located next to the first slewing device 31. When the excavator 10 is viewed in plan in a direction parallel to the reference axis K, the second boom 71 is rotatable on both sides of the first rotation axis 51J. More specifically, when the excavator 10 is viewed in plan in a direction parallel to the reference axis K, the second boom 71 of this embodiment is rotatable on both sides of the first rotation axis 51J, straddling a half-line that extends from the first slewing axis 31J toward the opposite side of the support wall 27. This half-line is referred to as the boom half-line. The second boom 71 is rotatable to one side of the boom half-line up to a first slewing angle, and also rotatable to the other side of the boom half-line up to a first slewing angle. The first slewing angle is approximately 90 degrees. In other words, when the excavator 10 is viewed from above in a direction parallel to the reference axis K, the first slewing device 31 can drive the second boom 71 to rotate both to one side and to the other side of the boom half-line. More specifically, the first slewing device 31 can drive the second boom 71 to rotate to one side of the boom half-line up to a first slewing angle. Furthermore, the first slewing device 31 can drive the second boom 71 to rotate to the other side of the boom half-line up to a first slewing angle.

[0066] As shown in Figure 1, assuming that the excavator 10 is viewed from above in a direction parallel to the reference axis K, the following can be said about the rotation of the second boom 71. The imaginary straight line connecting the first end 71A of the second boom 71 and the second end 71B, which is the end opposite to the first end 71A, is called the third imaginary straight line 42E. In this embodiment, this third imaginary straight line 42E corresponds to the imaginary straight line connecting the first pivot axis 31J and the second pivot axis 32J, which will be described later. Rotation of the second boom 71 to one side with respect to the first rotation axis 51J means that the third imaginary straight line 42E rotates to one side with respect to the first rotation axis 51J, centered on the first pivot axis 31J. Similarly, rotation to the other side means that the third imaginary straight line 42E rotates to the other side with respect to the first rotation axis 51J, centered on the first pivot axis 31J.

[0067] <Second Rotating Device> As shown in Figure 3, the second slewing device 32 is located near the second end 71B of the second boom 71. The second slewing device 32 is located on the downward side relative to the second boom 71. The second slewing device 32 is configured similarly to the first slewing device 31. That is, the second slewing device 32 comprises a main body 32A having a reduction gear in addition to an electric motor which is the drive source, and a second slewing member 32B that rotates by receiving torque from the main body 32A. The outer casing of the main body 32A is fixed to the second end 71B of the second boom 71. The second slewing member 32B rotates about the second slewing axis 32J by receiving torque from the main body 32A. The second slewing axis 32J extends approximately parallel to the reference axis K at a position different from the first slewing axis 31J and the reference axis K. The second rotation axis 52J passes through the second end 71B of the second boom 71. The second slewing member 32B, and by extension the second slewing device 32, outputs torque centered on this second slewing axis 32J. The second slewing member 32B can rotate around its entire circumference in both forward and reverse directions according to the rotation direction of the electric motor. The second slewing device 32, together with the first slewing device 31, constitutes the second drive unit.

[0068] <Second Arm> As shown in Figure 3, the second arm 72 is positioned on the lower side relative to the second slewing device 32. The second arm 72 is a long, plate-like or columnar shape. In this embodiment, the second arm 72 extends in a straight line. The first longitudinal end 72A of the second arm 72 is positioned where the second slewing axis 32J passes through. The second slewing member 32B of the second slewing device 32 is fixed to the first end 72A of the second boom 71. The second boom 71 rotates integrally with the second slewing member 32B. In other words, the second arm 72 rotates about the second slewing axis 32J in response to torque from the second slewing device 32. To put it another way, the second slewing device 32 outputs torque to the second arm 72 about the second slewing axis 32J. Thus, the first end 72A of the second arm 72 is connected to the second slewing device 32. At the same time, the first end 72A of the second arm 72 is connected to the second end 71B of the second boom 71 via the second slewing device 32. In other words, the first end 72A of the second arm 72 corresponds to the connection point with the second boom 71.

[0069] As described above, the second arm 72 rotates in response to torque from the second slewing device 32. The second slewing member 32B of the second slewing device 32 is rotatable around the entire circumference in both forward and reverse directions about the second slewing axis 32J. Therefore, as shown in Figure 1, when the excavator 10 is viewed from above in a direction parallel to the reference axis K, the second arm 72 is rotatable on both sides of the third virtual straight line 42E connecting the first slewing axis 31J and the second slewing axis 32J. In detail, the second arm 72 in this embodiment is rotatable on both sides of the third virtual straight line 42E, crossing a third virtual half-line that extends from the second slewing axis 32J in the opposite direction from the first slewing axis 31J, in conjunction with the arrangement of the second attachment 73, which will be described later. More specifically, the second arm 72 can rotate to one side of the third virtual half-line up to a second rotation angle, and can also rotate to the other side of the third virtual half-line up to a second rotation angle. The second rotation angle is approximately 180 degrees. In other words, when the excavator 10 is viewed from above in a direction parallel to the reference axis K, the second slewing device 32 can rotate the second arm 72 both to one side and to the other side of the third virtual half-line. More specifically, the second slewing device 32 can rotate the second boom 71 to one side of the third virtual half-line up to a second rotation angle. Furthermore, the second slewing device 32 can rotate the second arm 72 to the other side of the third virtual half-line up to a second rotation angle.

[0070] As shown in Figure 1, assuming that the excavator 10 is viewed from above in a direction parallel to the reference axis K, the following can be said about the rotation of the second arm 72. The imaginary straight line connecting the first end 72A of the second arm 72 and the second end 72B, which is the end opposite to the first end 72A, is called the fourth imaginary straight line 42F. In this embodiment, this fourth imaginary straight line 42F corresponds to the imaginary straight line connecting the second pivot axis 32J and the operation axis 74J, which will be described later. Rotation of the second arm 72 to one side relative to the third imaginary straight line 42E means that the fourth imaginary straight line 42F rotates to one side relative to the third imaginary straight line 42E with respect to the second pivot axis 32J. Similarly, rotation to the other side means that the fourth imaginary straight line 42F rotates to the other side relative to the third imaginary straight line 42E with respect to the second pivot axis 32J.

[0071] <Second Attachment> As shown in Figure 3, the second attachment 73 is located near the second end 72B of the second arm 72. The second attachment 73 is an electrically operated telescopic device. Specifically, the second attachment 73 comprises a power generator 74 and a second work tool 75.

[0072] The power generator 74 comprises a main body 74A and a rod, which is an example of an operating member 74B. The main body 74A includes a cylinder, an electric motor, and a conversion mechanism. The cylinder is the outer casing of the main body 74A. The cylinder is cylindrical. The cylinder is fixed to the second end 72B of the second arm 72. The cylinder is located on the upward side relative to the second arm 72. The operating axis 74J, which is the central axis of the cylinder, extends approximately parallel to the first pivot axis 31J at a different position from the first pivot axis 31J and the second pivot axis 32J. The operating axis 74J passes through the second end 72B of the second arm 72. The electric motor is the drive source of the power generator 74. Power is supplied to the electric motor from a battery (not shown). Depending on the power supply to the electric motor, the output shaft of the electric motor can output torque in both forward and reverse directions. The conversion mechanism converts the rotation of the output shaft of the electric motor into the linear motion of the operating member 74B. Examples of conversion mechanisms include a ball screw mechanism and a rack and pinion mechanism. The operating member 74B protrudes from the inside to the outside of the cylinder. The operating member 74B passes vertically through the second end 72B of the second arm 72. The operating member 74B reciprocates along the operating axis 74J in response to the drive of the electric motor. The amount of protrusion of the operating member 74B relative to the cylinder changes in accordance with the reciprocating motion of the operating member 74B. At the same time, the power generator 74 expands and contracts in the direction along the operating axis 74J.

[0073] The second working tool 75 is fixed to the lower end of the operating member 74B. The second working tool 75 comprises a bifurcated first part and a second part. The configuration of the first part and the second part is the same. Therefore, only the first part will be described here, and the description of the second part will be omitted. As shown in Figure 5, when the first part is viewed from the opposite side from the second part, the first part comprises a rectangular connecting plate 75A and a plurality of claws 75B. The edge corresponding to the upper edge of the connecting plate 75A is fixed to the lower end of the operating member 74B. The plurality of claws 75B protrude from the lower edge of the connecting plate 75A. The plurality of claws 75B are arranged along the lower edge of the connecting plate 75A. In this embodiment, there are three claws 75B. However, the number of claws 75B is not limited to three.

[0074] <Control device> As shown in Figure 1, the excavator 10 is equipped with a control device 45. The control device 45 is located, for example, inside the upper body 20. Note that the location of the control device 45 in each figure is for convenience only. The control device 45 may include a processing circuit that includes one or more processors that execute various processes according to a computer program (software). Note that the control device 45 may also include a processing circuit that includes one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), that execute at least some of the various processes, or a processing circuit that includes a combination of the above processors and dedicated hardware circuits. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer. Memory includes electrically rewritable non-volatile memory. The control device 45 is equipped with a communication circuit. The communication circuit is a circuit for wireless communication with a controller 46 held by the user outside the excavator 10. The excavator 10 and the controller 46 constitute the excavator system 47.

[0075] The control device 45 controls various parts of the excavator 10. The devices controlled by the control device 45 include the following: the first drive unit 51, the second drive unit 52, the third drive unit 53, the first slewing device 31, the second slewing device 32, the power generator 74 of the second attachment 73, the main slewing device 30, and the traveling device 16. The control device 45 controls the controlled devices in response to command signals transmitted from the controller 46. For example, the control device 45 outputs a control signal to the first drive unit 51 in response to a command signal. As a result, the control device 45 rotates the first boom 61.

[0076] <Effects and Effects of the Embodiment> (1) As shown by arrow 61P in Figure 6, the first boom 61 of this embodiment is rotatable to one side with respect to the reference axis K in a specific plan view. Also, as shown by arrow 61Q in Figure 6, the first boom 61 is also rotatable to the other side with respect to the reference axis K in a specific plan view. In other words, in the excavator 10 of this embodiment, the first boom 61 and by extension the first arm 62 connected to the first boom 61 can be extended to both one side and the other side with respect to the reference axis K. Therefore, in the excavator 10 of this embodiment, a large range of motion of the first mechanism 41 can be secured. As a result, the working range of the excavator 10 is expanded.

[0077] (2) As shown by the solid line in Figure 6, the first boom 61 can rotate to an angle exceeding 90 degrees with respect to the reference axis K in a specific plan view. Consequently, the second end 61B of the first boom 61 can reach below the top surface 23 of the upper body 20. At the same time, the first boom 61 and, by extension, the first arm 62 connected to the first boom 61 can reach a position close to the ground G. In other words, in the excavator 10 of this embodiment, work can be performed over a wide range of vertical movement on both one side and the other side of the reference axis K.

[0078] (3) The first arm 62 of this embodiment is rotatable in both directions with respect to the first virtual half-line extending from the second rotation axis 52J to the opposite side of the first rotation axis 51J along the first virtual straight line 41E. Therefore, as shown by arrow 62P in Figure 6, the first arm 62 is rotatable up and down with respect to the first boom 61 when the first boom 61 is positioned on one side with respect to the reference axis K in a specific plan view. Also, as shown by arrow 62Q in Figure 6, the first arm 62 is rotatable up and down with respect to the first boom 61 even when the first boom 61 is positioned on the other side with respect to the reference axis K in a specific plan view. Furthermore, the first attachment 63 of this embodiment is rotatable in both directions with respect to the second virtual straight line 41F connecting the second rotation axis 52J and the third rotation axis 53J. Therefore, as indicated by arrow 65P in Figure 6, the first attachment 63 is rotatable up and down relative to the first arm 62 when the first boom 61 is positioned on one side with respect to the reference axis K in a specific plan view. Also, as indicated by arrow 65Q in Figure 6, the first attachment 63 is rotatable up and down relative to the first arm 62 even when the first boom 61 is positioned on the other side with respect to the reference axis K in a specific plan view. In this configuration of the embodiment, the first arm 62 and the first attachment 63 can be positioned to a position suitable for work regardless of the rotational position of the first boom 61.

[0079] (4) As shown in Figure 6, the side surface 22 of the upper body 20 is an inclined surface that is inclined with respect to the reference axis K. Therefore, even when the first boom 61 is inclined with respect to the top surface 23 of the upper body 20, the first boom 61 does not interfere with the side surface 22 of the upper body 20. In other words, because the side surface 22 of the upper body 20 is inclined with respect to the reference axis K, the first boom 61 is allowed to be inclined downward with respect to the top surface 23 of the upper body 20.

[0080] In order to realize a configuration in which the first boom 61 is tilted downward with respect to the top surface 23 of the upper body 20, for example, the first drive unit 51 and, consequently, the first end portion 61A of the first boom 61 could be positioned considerably higher than the top surface 23 of the upper body 20. However, if such a structure is adopted, for example, the support wall 27 would be enlarged upward, and the mounting position of the first boom 61 to the support wall 27 would be shifted further upward. In this case, since the position of the first mechanism 41 as a whole is shifted further upward, there is a concern that the entire excavator 10 will become larger.

[0081] In this respect, as in this embodiment, if the side surface 22 of the upper body 20 is made inclined, the range of motion of the first mechanism 41, including the first boom 61, can be greatly increased without increasing the size of the excavator 10.

[0082] (5) As shown in Figure 6, the first boom 61 is connected to the main slewing device 30 via a support wall 27 and a connecting member 25. The output member 30B of the main slewing device 30 is capable of slewing around the entire circumference of the reference axis K and the main slewing axis 30J. As the output member 30B rotates, the excavator 10 of this embodiment can move the first boom 61, and by extension the first arm 62 connected to the first boom 61, to any position in the front, back, left, or right directions. For example, as shown by the arrow 30P in Figure 7, the first boom 61, the first arm 62, and the first attachment 63 can move to a position rotated 90 degrees clockwise from the slewing position in Figure 1.

[0083] Here, in order to realize a configuration in which the first boom 61 can be rotated around the entire circumference of the reference axis K, it is conceivable to make the upper body 20 itself rotatable relative to the lower body 14. However, in order to rotate the entire upper body 20, the following configuration is necessary. That is, it is necessary to support the upper body 20 so that it can rotate while supporting the total weight of the upper body 20 and all the components attached to it. For this purpose, a considerably large bearing is required. Also, in consideration of the above weight, the torque required to drive the rotation of the upper body 20 will be considerably large. Therefore, the drive device that drives this rotation may become large.

[0084] In this respect, in the configuration of this embodiment, the bearing that rotatably supports the connecting member 25 only needs to be able to support the total weight of the group of members attached to the connecting member 25. Therefore, this bearing can be considerably smaller than the bearing used when supporting the upper body 20. Moreover, in consideration of this smaller weight, the torque required to drive the rotation of the connecting member 25 is considerably smaller than when rotating the entire upper body 20. Therefore, it is possible to avoid adopting a large main slewing device 30, and the size of the main slewing device 30 can be suppressed.

[0085] (6) As shown in Figure 6, the upper body 20 is frustoconical in shape. Therefore, the side surface 22 of the upper body 20 is inclined with respect to the reference axis K over the entire circumferential direction around the reference axis K. As described in (5) above, the first boom 61 is rotatable over the entire circumferential direction around the reference axis K. If the side surface 22 of the upper body 20 is inclined over the entire circumference, the first boom 61 can be tilted downwards with respect to the top surface 23 at each position in the circumferential direction around the reference axis K. Furthermore, by utilizing the structure that inclins the side surface 22 of the upper body 20, the size of the excavator 10 can be suppressed from the same viewpoint as in (4) above.

[0086] (7) As shown in Figure 6, the first end portion 61A, which is the vertical rotation center of the first boom 61, is located approximately in the center of the upper body 20 in a direction perpendicular to both the first rotation axis 51J and the reference axis K. In this case, the range of motion of the first boom 61 and, by extension, the first arm 62 connected to the first boom 61, is not biased towards either side of the center of the upper body 20. In other words, in the excavator 10 of this embodiment, a large range of motion of the first mechanism 41 can be secured with respect to both one side and the other side of the center of the upper body 20.

[0087] (8) As shown in Figure 6, the first work tool 65 of the first attachment 63 is equipped with a first bucket 65A and a second bucket 65B connected to each other's bottom walls 67D. When such a first work tool 65 is used, the following becomes possible. That is, as shown by the solid line first work tool 65 in Figure 6, with this first work tool 65, when the first boom 61 is positioned on one side with respect to the reference axis K in a specific plan view, the first bucket 65A can perform a pull-cutting operation and the second bucket 65B can perform a push-cutting operation. On the other hand, as shown by the dashed line first work tool 65 in Figure 6, with this first work tool 65, when the first boom 61 is positioned on the other side with respect to the reference axis K in a specific plan view, the second bucket 65B can perform a pull-cutting operation and the first bucket 65A can perform a push-cutting operation.

[0088] (9) As shown by the dashed line 68Q in Figure 4, in this embodiment, when the first attachment 63 is rotated once, the rotational trajectory of the protruding end of the claw 68 of the first bucket 65A and the rotational trajectory of the protruding end of the claw 68 of the second bucket 65B overlap. In other words, with respect to a certain rotational position, the position of the protruding end of the claw 68 is the same when the first bucket 65A reaches that rotational position and when the second bucket 65B reaches that rotational position. In this case, since the position of the claw 68 is the same when pulling and pushing are performed, the user does not need to adjust the position of the first attachment 63, or its connection point, the first arm 62 and the first boom 61, to suit each operation. Therefore, the user is less burdened with operation when performing pulling and pushing work.

[0089] (10) As shown in Figure 1, when the excavator 10 is viewed in plan view facing a direction parallel to the reference axis K, the second boom 71 of the second mechanism 42 can rotate approximately 90 degrees in both forward and reverse directions with respect to the first rotation axis 51J, about the first pivot axis 31J. Furthermore, the second arm 72 can rotate around the second pivot axis 32J over almost the entire circumference. Therefore, when the virtual plane perpendicular to the reference axis K is defined as the horizontal plane, the second mechanism 42, including the second boom 71 and the second arm 72, can operate over a wide range on the horizontal plane. For example, as shown by arrow 71P in Figure 7, the second boom 71 can reach a position rotated approximately 30 degrees clockwise from the first rotation axis 51J. Also, for example, as shown by arrow 72P in Figure 7, the second arm 72 can reach a position rotated 30 degrees clockwise from the third virtual straight line 42E. Thus, in the excavator 10 of this embodiment, a large range of motion for the second mechanism 42 can be secured. As a result, the working range of the excavator 10 is expanded.

[0090] (11) As shown by arrow 74P in Figure 3, the second attachment 73 of the second mechanism 42 extends and retracts vertically. Therefore, as described in (10) above, the second mechanism 42 can perform vertical work while increasing the range of motion on the horizontal plane.

[0091] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0092] Either the first mechanism 41 or the second mechanism 42 may be abolished. The overall configuration of the second mechanism 42 is not limited to the example of the embodiment described above. The second mechanism 42 only needs to have a second arm 72 connected to the second boom 71, and a second attachment 73 connected to the opposite side of the second arm 72 from the connection point with the second boom 71. As long as such a configuration can be realized, various parts of the second mechanism 42 may be appropriately modified. For example, the relative positions of the second boom 71, the second arm 72, and the second attachment 73 in a direction parallel to the reference axis K may be changed from the example of the embodiment described above. Specifically, one possibility is to position the second arm 72 on the upward side relative to the second boom 71.

[0093] The manner in which the second attachment 73 is connected to the second arm 72 is not limited to the examples of the above embodiment. For example, the upper end of the second attachment 73 may be fixed to the lower surface of the second end 72B of the second arm 72. The manner of connection is not limited as long as the second attachment 73 can be connected to the second arm 72.

[0094] The configuration of the second attachment 73 is not limited to the examples of the above embodiment. The second attachment 73 may be any device, mechanism, or tool that is effective in various operations using the excavator 10, not limited to an extension device.

[0095] The configuration of the second arm 72 is not limited to the examples of the above embodiment. The second arm 72 may be curved or bent along its length. If the second arm 72 is a long member as a whole, it is preferable in order to increase the range of motion of the second mechanism 42.

[0096] The second slewing angle of the second arm 72, and consequently the rotation range of the second arm 72, is not limited to the examples of the above embodiment. The second slewing angle may differ on one side and the other side with respect to the third virtual straight line 42E connecting the first slewing axis 31J and the second slewing axis 32J. The second arm 72 may be rotatable 360 ​​degrees on both sides of the third virtual straight line 42E. The second arm 72 may be rotatable only on one side of the third virtual straight line 42E. The second arm 72 only needs to be rotatable with respect to the second boom 71.

[0097] It is not essential that the second arm 72 is rotatable relative to the second boom 71. If the second arm 72 does not need to be rotatable relative to the second boom 71, the second slewing device 32 may be eliminated.

[0098] The configuration of the second boom 71 is not limited to the examples of the above embodiments. Similar to the second arm 72, if the second boom 71 is long overall, it is preferable in order to increase the range of motion of the second mechanism 42.

[0099] The first slewing angle of the second boom 71, and consequently the rotation range of the second boom 71, is not limited to the examples of the above embodiment. The first slewing angle may differ on one side and the other side with respect to the first rotation axis 51J. Depending on the arrangement of the second boom 71, the virtual straight line that serves as the reference for the rotation of the second boom 71 may not be the first rotation axis 51J. The second boom 71 only needs to be connected to the vehicle body 12 so that it can rotate in at least one direction on one side and the other side with respect to a certain reference straight line. The second boom 71 may be able to rotate 360 ​​degrees in both forward and reverse directions around the first slewing axis 31J.

[0100] The arrangement of the first pivoting device 31 on the connecting member 25 is not limited to the example of the above embodiment. For example, the first pivoting device 31 may be located at the center of the circle of the connecting member 25. The mounting target for the first slewing device 31 is not limited to the connecting member 25. The first slewing device 31 can be attached directly or indirectly to any part of the upper body 20 and, consequently, the vehicle body 12. In this case, the location of the first slewing device 31 on the vehicle body 12 may be appropriately designed considering the range of motion of the second boom 71 and the configuration of the vehicle body 12. In other words, the arrangement of the first slewing device 31 is not limited to the example of the above embodiment.

[0101] The configuration of the first slewing device 31 and the manner in which the first slewing device 31 connects the upper body 20 and the second boom 71 are not limited to the examples of the above embodiment. For example, in the first slewing device 31, the electric motor may be positioned on the upward side relative to the second boom 71, while the reduction gear may be positioned between the upper body 20 and the second boom 71. In addition, the output shaft of the electric motor may be passed through the second boom 71 and connected to the reduction gear. Furthermore, the output side configuration of the reduction gear may be designed so that the torque output by the reduction gear is transmitted to the second boom 71. As long as the torque output by the first slewing device 31 can rotate the second boom 71 relative to the vehicle body 12, the manner in which the first slewing device 31 connects the vehicle body 12 and the second boom 71 is not limited. Also, the first slewing device 31 only needs to include an electric motor and be configured to output torque around the first slewing axis 31J that extends vertically above and below the vehicle body 12. The reduction gear may be omitted from the first slewing device 31.

[0102] It is not essential that the second boom 71 is connected to the upper body 20 and thus to the vehicle body 12 via the first slewing device 31. In other words, the way in which the second boom 71 is connected to the vehicle body 12 is not limited to the example of the above embodiment. As long as the second boom 71 can be rotatably connected to the vehicle body 12, the manner of connection is not limited. Furthermore, depending on how the way in which the second boom 71 is connected to the vehicle body 12 is changed from the example of the above embodiment, the connection point of the second boom 71 to the vehicle body 12 may be somewhere other than the top surface 23 of the upper body 20. In other words, the connection point of the second boom 71 to the vehicle body 12 is not limited to the example of the above embodiment. The second boom 71 only needs to be connected somewhere on the vehicle body 12. Moreover, the location of the connection point of the second boom 71 to the vehicle body 12 may be off-center from the vehicle body 12 in a direction perpendicular to both the first rotation axis 51J and the reference axis K. In other words, the arrangement of the connection point of the second boom 71 to the vehicle body 12 is not limited to the example of the above embodiment.

[0103] Similar to the above-described examples of modifications to the first slewing device 31, the configuration of the second slewing device 32 and the manner in which the second boom 71 and the second arm 72 are connected by the second slewing device 32 are not limited to the above-described examples. As long as the torque output by the second slewing device 32 can rotate the second arm 72 relative to the second boom 71, the manner in which the second boom 71 and the second arm 72 are connected by the second slewing device 32 is not limited. Furthermore, the second slewing device 32 may include an electric motor and be configured to output torque around a second slewing axis 32J that is parallel to the first slewing axis 31J. The reduction gear may be eliminated from the second slewing device 32.

[0104] It is not mandatory for the second arm 72 to be connected to the second boom 71 via the second slewing device 32. As mentioned above, the second slewing device 32 may be omitted. Regardless of the presence or absence of the second slewing device 32, the manner in which they are connected is not limited, as long as the second arm 72 can be connected to the second boom 71.

[0105] The overall configuration of the first mechanism 41 is not limited to the example of the above embodiment. The first mechanism 41 is sufficient if the first arm 62 is connected to the 61st boom, and the first attachment 63 is connected to the opposite side of the connection point between the first arm 62 and the first boom 61. As long as such a configuration can be realized, various parts of the first mechanism 41 may be appropriately modified. For example, the relative positions of the first boom 61, the first arm 62, and the first attachment 63 in a direction parallel to the first rotation axis 51J may be changed from the example of the above embodiment. Specifically, the first attachment 63 may be positioned on the opposite side of the first arm 62 from the first boom 61.

[0106] The configuration of the first attachment 63 is not limited to the examples of the above embodiment. For example, the first bucket 65A and the second bucket 65B may be arranged asymmetrically in a particular plan view. Also, the first bucket 65A and the second bucket 65B may have different shapes. Even if the arrangement of the first bucket 65A and the second bucket 65B is asymmetrical, or if the shapes of the first bucket 65A and the second bucket 65B are different, the effects of (9) above can be enjoyed as long as the first bucket 65A and the second bucket 65B are configured to satisfy the first condition.

[0107] In the first attachment 63, it is not essential that the first bucket 65A and the second bucket 65B satisfy the first condition. Even if the first bucket 65A and the second bucket 65B do not satisfy the first condition, the effects of (8) above can be enjoyed by adopting a first attachment 63 in which the first bucket 65A and the second bucket 65B are connected in opposite directions. Furthermore, it is not essential that the first attachment 63 has both the first bucket 65A and the second bucket 65B. In other words, in the first attachment 63, either the first bucket 65A or the second bucket 65B may be omitted.

[0108] • The first attachment 63 may be something other than a box-shaped bucket. For example, an extendable device like the second attachment 73 may be used as the first attachment 63. In other words, the first attachment 63 is not limited to one that rotates relative to the first arm 62. If a first attachment 63 that does not require rotation relative to the first arm 62 is used, the third drive device 53 may be omitted. Similar to the second attachment 73, the first attachment 63 may be any device, mechanism, or equipment that is effective in various operations using the excavator 10.

[0109] - When a type of first attachment 63 that rotates relative to the first arm 62 is adopted, the rotation range of the first attachment 63 is not limited to the example of the above embodiment. The first attachment 63 may be rotatable within different rotation ranges on one side and the other side with respect to the second virtual straight line 41F connecting the second rotation axis 52J and the third rotation axis 53J. The first attachment 63 may be rotatable only in one direction relative to the second virtual straight line 41F, either one side or the other side. The first attachment 63 only needs to be rotatable relative to the first arm 62.

[0110] The configuration of the first arm 62 is not limited to the examples of the above embodiment. The first arm 62 may be curved or bent along its length. If the first arm 62 is long overall, it is preferable in order to increase the range of motion of the first mechanism 41.

[0111] The second rotation angle of the first arm 62, and consequently the rotation range of the first arm 62, is not limited to the examples of the above embodiment. The second rotation angle may differ on one side and the other side with respect to the first virtual straight line 41E connecting the first rotation axis 51J and the second rotation axis 52J. The first arm 62 may be rotatable 360 ​​degrees on both sides of the first virtual straight line 41E. The first arm 62 may be rotatable only on one side of the first virtual straight line 41E. The first arm 62 only needs to be rotatable with respect to the first boom 61.

[0112] It is not essential that the first arm 62 is rotatable relative to the first boom 61. If the first arm 62 does not need to be rotatable relative to the first boom 61, the second drive unit 52 may be omitted.

[0113] The configuration of the first boom 61 is not limited to the examples of the above embodiments. Similar to the first arm 62, if the first boom 61 is long overall, it is preferable in order to increase the range of motion of the first mechanism 41.

[0114] The first rotation angle of the first boom 61, and consequently the rotation range of the first boom 61, is not limited to the examples of the above embodiment. The first rotation angle may differ on one side and the other side with respect to the reference axis K. The first boom 61 only needs to be rotatable on both sides with respect to the reference axis K. In order to ensure a large range of motion for the first mechanism 41, it is preferable that the first boom 61 be rotatable by 90 degrees or more on one side with respect to the reference axis K and by 90 degrees or more on the other side with respect to the reference axis K.

[0115] The configuration of the first drive unit 51 and the manner in which the first drive unit 51 connects the support wall 27 and the first boom 61 are not limited to the examples of the above embodiment. For example, the electric motor in the first drive unit 51 may be positioned on the opposite side of the support wall 27 from the first boom 61, while the reduction gear may be positioned between the support wall 27 and the first boom 61. In addition, the output shaft of the electric motor may be passed through the support wall 27 and connected to the reduction gear. The output side of the reduction gear may be designed so that the torque output by the reduction gear is transmitted to the first boom 61. Alternatively, for example, the electric motor may be positioned on the opposite side of the support wall 27 from the first boom 61, while the reduction gear may be positioned between the support wall 27 and the first boom 61. Even in this case, the torque of the electric motor can be transmitted to the reduction gear by passing the output shaft of the electric motor through the first boom 61 and connecting it to the reduction gear. Furthermore, for example, the first end 61A of the first boom 61 may be branched into two, and the support wall 27 may be positioned between the two branched first end 61A. With this configuration in place, the first end 61A of the first boom 61 and the support wall 27 may be connected by the first drive unit 51 using an appropriate method. As long as the torque output by the first drive unit 51 can rotate the first boom 61 relative to the support wall 27 and thus to the vehicle body 12, the manner in which the first drive unit 51 connects the support wall 27 and the first boom 61 is not limited. Furthermore, the first drive unit 51 may include an electric motor and be configured to output torque centered on a rotation axis perpendicular to the reference axis K. The reduction gear may be omitted from the first drive unit 51.

[0116] It is not essential that the first boom 61 is connected to the upper body 20 and thus to the vehicle body 12 via the first drive unit 51. In other words, the way in which the first boom 61 is connected to the vehicle body 12 is not limited to the example of the above embodiment. As long as the first boom 61 can be rotatably connected to the vehicle body 12, the manner of connection is not limited. Furthermore, depending on how the way in which the first boom 61 is connected to the vehicle body 12 is changed from the example of the above embodiment, the connection point of the first boom 61 to the vehicle body 12 may be somewhere other than the top surface 23 of the upper body 20. In other words, the connection point of the first boom 61 to the vehicle body 12 is not limited to the example of the above embodiment. The first boom 61 only needs to be connected somewhere on the vehicle body 12. Moreover, the arrangement of the connection point of the first boom 61 to the vehicle body 12 may be at a position off-center from the vehicle body 12 in a direction perpendicular to both the first rotation axis 51J and the reference axis K. In other words, the arrangement of the connection points of the first boom 61 to the vehicle body 12 is not limited to the example of the above embodiment.

[0117] Similar to the above-described examples of modifications to the first drive unit 51, the configuration of the second drive unit 52 and the manner in which the second drive unit 52 connects the first boom 61 and the first arm 62 are not limited to the above-described examples. As long as the torque output by the second drive unit 52 can rotate the first arm 62 relative to the first boom 61, the manner in which the second drive unit 52 connects the first boom 61 and the first arm 62 is not limited. Furthermore, the second drive unit 52 may include an electric motor and be configured to output torque centered on a second rotation axis 52J parallel to the first rotation axis 51J. The reduction gear may be eliminated from the second drive unit 52.

[0118] It is not mandatory for the first arm 62 to be connected to the first boom 61 via the second drive unit 52. As mentioned above, the second drive unit 52 may be omitted. Regardless of the presence or absence of the second drive unit 52, the manner in which they are connected is not restricted as long as the second arm 72 can be connected to the second boom 71.

[0119] Similar to the above-described examples of modifications to the first drive unit 51 and the second drive unit 52, the configuration of the third drive unit 53 and the manner in which the third drive unit 53 connects the first arm 62 and the first attachment 63 are not limited to the above-described examples of embodiments. As long as the torque output by the third drive unit 53 can rotate the first attachment 63 relative to the first arm 62, the manner in which the third drive unit 53 connects the first arm 62 and the first attachment 63 is not limited. Furthermore, the third drive unit 53 may include an electric motor and be configured to output torque centered on a third rotation axis 53J parallel to the first rotation axis 51J. The reduction gear may be eliminated from the third drive unit 53.

[0120] It is not mandatory for the first attachment 63 to be connected to the first arm 62 via the third drive unit 53. As mentioned above, the third drive unit 53 may be omitted. Regardless of the presence or absence of the third drive unit 53, the manner in which they are connected is not limited, as long as the first attachment 63 can be connected to the first arm 62.

[0121] The configuration and arrangement of the support wall 27 are not limited to the examples of the above embodiment. The support wall 27 may be appropriately configured and arranged in a way that is suitable in terms of connecting the first boom 61. The support wall 27 is not mandatory. If the first boom 61 can be connected to the vehicle body 12 using a configuration other than the wall section designated as the support wall 27, the support wall 27 may be omitted.

[0122] The configuration and arrangement of the connecting member 25 are not limited to the examples of the above embodiment. The connecting member 25 only needs to be able to transmit the torque output by the main slewing device 30 to the first boom 61. As long as this can be achieved, the configuration and arrangement of the connecting member 25 can be changed as appropriate.

[0123] The configuration and arrangement of the main pivoting device 30 that pivots the connecting member 25 are not limited to the examples of the above embodiment. The main pivoting device 30 only needs to be able to output torque around the main pivoting axis 30J which is parallel to the reference axis K. The rotation range of the output member 30B in the main pivoting device 30 is not limited to 360 degrees. The reduction gear may be eliminated from the main pivoting device 30. The main pivoting axis 30J and the reference axis K may be misaligned.

[0124] The main slewing device 30 may be abolished. In this case, the connecting member 25 may be abolished along with the main slewing device 30. If the main slewing device 30 and the connecting member 25 are abolished, for example, the support wall 27 can be directly attached to the upper body 20.

[0125] It is not essential to treat the central axis of the upper body 20 as the reference axis K. The reference axis K can be any axis extending vertically from the vehicle body 12. The vertical position of the vehicle body 12 can be defined by the positional relationship between the lower body 14 and the upper body 20, as in the above embodiment, or by the positional relationship between the ground G and the vehicle body 12. In this case, the ground G can be, for example, a horizontal plane created by virtually extending the lower surfaces of the crawlers on both the left and right running gears 16.

[0126] The configuration of the upper body 20 is not limited to the examples of the above embodiment. For example, the inferior angle θ formed by the top surface 23 and the side surface 22 of the upper body 20 may be changed from 120 degrees. Furthermore, if the main slewing device 30 is abolished as in the above modification example, the upper body 20 may be made into a shape other than a frustoconical shape. Even if the upper body 20 is not frustoconical, it is effective in securing a large range of motion for the first boom 61 if the shape of the upper body 20 is as follows. That is, in a specific plan view, it is preferable that the upper body 20 has an inclined surface that is inclined so as to approach the reference axis K as it goes upward, and a top surface that is connected to the uppermost end of the inclined surface and is perpendicular to the reference axis K. Then, if the first boom 61 is connected to the top surface of such an upper body 20, the first boom 61 can be inclined downward relative to the top surface so as to follow the inclined surface. However, it is not essential that the upper body 20 has an inclined surface and a top surface. As described in (4) above, by adopting an appropriate configuration, such as expanding the support wall 27 upwards, the range of motion of the first boom 61 can be increased without using an inclined surface.

[0127] The upper body 20 and the lower body 14 may be connected such that the upper body 20 can rotate relative to the lower body 14 around the reference axis K. For example, if the main slewing device 30 is to be abolished, such a connection configuration can be adopted to allow the first mechanism 41, etc., to be slewing to a position favorable for work.

[0128] The overall configuration of the vehicle body 12 is not limited to the examples of the above embodiments. For example, the vehicle body 12 may be composed of a single object without a partition between the lower body 14 and the upper body 20. The vehicle body 12 may be provided with a passenger seat and input devices such as switches and levers for operating the first mechanism 41 and the second mechanism 42, etc.

[0129] The construction machinery to which the configuration of the first mechanism 41, the second mechanism 42, and the vehicle body 12 connecting them, as described in the above embodiments and each of the modifications, is applied is not limited to the excavator 10. Any construction machine can have its working range widened by adopting at least one of the first mechanism 41 and the second mechanism 42.

[0130] In the above embodiment, a structure composed of multiple objects may be integrated, or conversely, a structure composed of a single object may be divided into multiple objects. Whether or not the objects are integrated, the structure should be configured in a way that achieves the objective of the invention.

[0131] An example of a case in which the shape of the vehicle body 12, the mounting method of the first drive unit 51 to the vehicle body 12, and the arrangement of the connection points of the first boom 61 to the vehicle body 12 are changed from the above embodiment will be explained using Figures 8 to 10. In the following, the excavator 110 shown in Figures 8 to 10 will be mainly described in terms of parts that differ from the above embodiment, and parts that overlap with the above embodiment will be omitted or simplified as appropriate. Note that in Figures 8 to 10, parts that function the same or substantially the same as those in Figures 1 to 7 are denoted by the same reference numerals as in Figures 1 to 7.

[0132] As shown in Figure 8, the excavator 110 comprises a body 12 and a pair of running gears 16. The body 12 comprises a lower body 14 and an upper body 114. The upper body 114 is located on the opposite side of the lower body 14 from the ground G. The upper body 114 is rectangular in shape. Both the upper and lower surfaces of the upper body 114 are substantially parallel to the ground G and, consequently, to the lower surfaces of the left and right crawlers. The interior of the upper body 114 is hollow. The configuration of the lower body 14 is the same as that of the above embodiment. The pair of running gears 16 are located on both the left and right sides of the lower body 14. The configuration of the running gears 16 is the same as that of the above embodiment. The way in which the front, rear, left, right, up, and down directions of the excavator 110 are defined is the same as that of the above embodiment.

[0133] As shown in Figure 8, the excavator 110 is equipped with a main slewing device 30. The main slewing device 30 is located inside the upper body 20. The main slewing device 30 is located at the front end of the upper body 20. As shown in Figure 10, the main slewing device 30 is located at the left end of the upper body 20. As shown in Figure 8, the central axis of the main slewing device 30 extends in the approximate Z direction. The outer casing of the main body 30A of the main slewing device 30 is fixed to the inner wall of the upper body 20. The output member 30B of the main slewing device 30 outputs torque centered on the main slewing axis 30J which extends in the approximate Z direction. The main slewing axis 30J is approximately perpendicular to both the upper and lower surfaces of the upper body 20. That is, the main slewing axis 30J extends vertically above and below the upper body 114. The main slewing axis 30J constitutes the reference axis K. The output member 30B is rotatable around its entire circumference in both forward and reverse directions, according to the rotation direction of the electric motor in the main body 30A. Although not shown in detail, the upper end of the output member 30B penetrates the upper surface of the upper body 20 and protrudes upward from that upper surface.

[0134] As shown in Figure 8, the excavator 110 includes a connecting member 25 and a support wall 27. The connecting member 25 is located on the upper side relative to the upper surface of the upper body 114. The connecting member 25 is fixed to the output member 30B of the main slewing device 30. The connecting member 25 rotates integrally with the output member 30B of the main slewing device 30. Although not shown in the figure, a bearing is positioned between the connecting member 25 and the upper surface of the upper body 114 to rotatably support the connecting member 25. The support wall 27 protrudes upward from the upper surface of the connecting member 25.

[0135] The excavator 110 is equipped with a first mechanism 41. The first mechanism 41, like the embodiment described above, includes a first drive unit 51, a second drive unit 52, a third drive unit 53, a first boom 61, a first arm 62, and a first attachment 63. The first mechanism 41 will be briefly described below, mainly focusing on the parts that differ from the embodiment described above. In the following description, the slewing angle of the connecting member 25 to which the first mechanism 41 is connected is assumed to be zero degrees. That is, the connecting member 25 is in the basic slewing position.

[0136] As shown in Figure 10, the first drive unit 51 is located to the right of the support wall 27. The outer casing of the main body 51A of the first drive unit 51 is fixed to the support wall 27. The first output member 51B of the first drive unit 51 outputs torque centered on a first rotation axis 51J that is substantially perpendicular to the reference axis K. The first rotation axis 51J extends substantially in the Y direction.

[0137] The first boom 61 is located to the right of the first drive unit 51. As shown in Figure 8, the first boom 61 is a long, plate-like shape overall. The first boom 61 is bent midway along its longitudinal direction. That is, in a specific plan view, the first boom 61 is V-shaped. The specific plan view is a plan view of the excavator 110 when viewed in a direction parallel to the first rotation axis 51J, similar to the embodiment described above. The first end 61A of the first boom 61 is located on the first rotation axis 51J. The first end 61A of the first boom 61 is connected to the first output member 51B of the first drive unit 51. The first boom 61 rotates about the first rotation axis 51J in response to torque from the first output member 51B of the first drive unit 51. In a specific plan view, the first boom 61 is rotatable both forward and backward with respect to the reference axis K. In detail, the first boom 61 is rotatable in both the forward and backward directions in a specific plan view, straddling a reference half-line that extends from the first rotation axis 51J on the reference axis K toward the opposite side from the connecting member 25. The first boom 61 can rotate more than 90 degrees forward relative to the reference half-line. Also, as shown in Figure 9, the first boom 61 is rotatable up to an upper limit angle in the backward direction relative to the reference half-line in a specific plan view. The upper limit angle is slightly greater than 90 degrees. When the first boom 61 rotates to the upper limit angle in the backward direction relative to the reference half-line, the corner of the bend in the first boom 61 contacts the upper surface of the upper body 114.

[0138] As described above, the first end 61A of the first boom 61 is connected to the support wall 27 via the first drive unit 51. As shown in Figure 10, the support wall 27 is located at the front end of the upper body 114. In consideration of the arrangement of the support wall 27, the first end 61A of the first boom 61, that is, the connection point between the first boom 61 and the upper body 114, is located forward of the center of the upper body 114 in the X direction. In other words, the first end 61A of the first boom 61 is located on one side of the center of the upper body 114 in a direction perpendicular to both the reference axis K and the first rotation axis 51J.

[0139] As shown in Figure 10, the second drive unit 52 is located to the right of the first boom 61. The outer casing of the main body 52A of the second drive unit 52 is fixed to the second end 61B of the first boom 61, which is opposite to the first end 61A. The second output member 52B of the second drive unit 52 outputs torque around the second rotation axis 52J. The second rotation axis 52J is located at a different position from the first rotation axis 51J and extends approximately parallel to the first rotation axis 51J. As shown in Figure 8, the second rotation axis 52J passes through the second end 61B of the first boom 61.

[0140] As shown in Figure 10, the first arm 62 is located to the right of the second drive unit 52. The first arm 62 is a long, plate-like structure. As shown in Figure 8, the first arm 62 extends in a straight line. As shown in Figure 10, the first end 62A of the first arm 62 is fixed to the second output member 52B of the second drive unit 52. In other words, the first end 62A of the first arm 62 is connected to the second end 61B of the first boom 61 via the second drive unit 52. The first arm 62 rotates about the second rotation axis 52J in response to torque from the second output member 52B of the second drive unit 52. As shown in Figure 8, in a specific plan view, the first arm 62 can rotate 360 ​​degrees in both directions with respect to the first virtual straight line 41E connecting the first rotation axis 51J and the second rotation axis 52J. In other words, in a specific plan view, the first arm 62 can perform the following rotational movements. The first arm 62 is rotatable on the first virtual line 41E, straddling a half-line extending from the second rotation axis 52J in the opposite direction from the first rotation axis 51J. Furthermore, the first arm 62 is rotatable on the first virtual line 41E, straddling a specific half-line 41V extending from the second rotation axis 52J towards the first rotation axis 51J. As shown in Figure 9, the specific half-line 41V is a half-line extending from the second rotation axis 52J and intersecting the first rotation axis 51J in a specific plan view.

[0141] As shown in Figure 10, the third drive unit 53 is located to the right of the first arm 62. The main body 53A of the third drive unit 53 is fixed to the second end 62B of the first arm 62, opposite to the first end 62A. The third output member 53B of the third drive unit 53 outputs torque around the third rotation axis 53J. The third rotation axis 53J extends approximately parallel to the first rotation axis 51J, but at a different position from the first rotation axis 51J and the second rotation axis 52J. As shown in Figure 8, the third rotation axis 53J passes through the second end 62B of the first arm 62.

[0142] As shown in Figure 10, the first attachment 63 is located to the right of the third drive unit 53. As shown in Figure 8, the first attachment 63 has a configuration in which one of the two buckets in the above embodiment is eliminated. That is, the first attachment 63 comprises a connecting piece 64 and one bucket 66. As shown in Figure 10, the bucket 66 comprises a bucket body 67 having an opening 67A and a plurality of claws 68 protruding from the opening edge of the bucket body 67. With respect to the Y direction, the bucket body 67 is located within the range of the upper body 114.

[0143] The connecting piece 64 of the first attachment 63 is fixed to the third output member 53B of the third drive unit 53. That is, the connecting piece 64 is connected to the second end 62B of the first arm 62 via the third drive unit 53. The connecting piece 64 and, by extension, the first attachment 63, receive torque from the third drive unit 53 and rotate about the third rotation axis 53J. As shown in Figure 8, in a specific plan view, the first attachment 63 is rotatable 360 ​​degrees in both directions with respect to the second virtual straight line 41F connecting the second rotation axis 52J and the third rotation axis 53J.

[0144] In the first mechanism 41, the first boom 61 and the first arm 62 are designed to satisfy the following first dimensional relationship in a specific plan view. The first dimensional relationship is that the distance from the first rotation axis 51J to the second rotation axis 52J is longer than the distance from the second rotation axis 52J to the third rotation axis 53J.

[0145] The first mechanism 41 can achieve the stowed position shown in Figures 9 and 10 by considering the rotation ranges of the first boom 61, the first arm 62, and the first attachment 63. As shown in Figure 9, in the stowed position, the bent corner of the first boom 61 is in contact with the upper surface of the upper body 114. The first arm 62 is positioned approximately 180 degrees around the second rotation axis 52J as the center of rotation relative to the first boom 61. In a specific plan view, the third rotation axis 53J is located on a specific half-line 41V. In this embodiment, the third rotation axis 53J is located between the second rotation axis 52J and the first rotation axis 51J in a specific plan view. In other words, when the first mechanism 41 is in the stowed position, the first boom 61, the first arm 62, and the first attachment 63 are arranged to overlap each other in a specific plan view. The first boom 61, the first arm 62, and the first attachment 63 can also be said to be arranged in parallel in a direction parallel to the first rotation axis 51J. By achieving this storage posture, the space used when storing the first mechanism 41 in the excavator 110 can be reduced.

[0146] As shown in Figure 10, the excavator 110 is equipped with a control device 45. The control device 45 controls the first mechanism 41 and the like. The control device 45 controls the first drive unit 51, the second drive unit 52, the third drive unit 53, and the like in response to command signals transmitted from the controller 46. The controller 46 and the excavator 110 constitute an excavator system 47.

[0147] The control device 45 is capable of performing a storage process. The storage process is the process of moving the first mechanism 41 to the storage position. The memory has a program for performing the storage process stored in advance. The CPU executes this program, and the control device 45 then performs the storage process.

[0148] Assuming a specific plan view, the state in which the first arm 62 has rotated relative to the first boom 61 to the point where the third rotation axis 53J is located on a specific half-line 41V is referred to as the first mode. In designing the first mechanism 41 to realize this first mode, configurations other than those shown in Figures 8 to 10 can be adopted. For example, in the example shown in Figure 11, the positional relationship between the first boom 61, the first arm 62, and the first attachment 63 in the direction parallel to the first rotation axis 51J is changed from the examples shown in Figures 8 to 10. Specifically, in the first mechanism 41 shown in Figure 11, both the first boom 61 and the first attachment 63 are located on the same side relative to the first arm 62 in the direction parallel to the first rotation axis 51J. At the same time, the first boom 61 and the first arm 62 are designed to satisfy the following second dimensional relationship in a specific plan view. The second dimensional relationship is that the distance from the first rotation axis 51J to the second rotation axis 52J is shorter than the distance from the second rotation axis 52J to the third rotation axis 53J. When this configuration is adopted, when the first mechanism 41 is in the first configuration, the third rotation axis 53J will be located on the opposite side of the first rotation axis 51J from the second rotation axis 52J on the specific half-line 41V. Alternatively, as shown in Figure 11, the first mechanism 41 may be rotated to an appropriate rotation position by the main slewing device 30 before being put into the first configuration.

[0149] An example of a case in which the shape of the vehicle body 12, the mounting manner of the first drive unit 51 to the vehicle body 12, and the arrangement of the connection points of the first boom 61 to the vehicle body 12 are changed from the above embodiment will be explained using Figures 12 and 13. In the following, with respect to the excavator 150 shown in Figures 12 and 13, the parts that differ from the above embodiment will be mainly explained, and the explanation of parts that overlap with the above embodiment will be omitted or simplified as appropriate. In Figures 12 and 13, parts that function the same or substantially the same as those in Figures 1 to 11 are denoted by the same reference numerals as in Figures 1 to 11.

[0150] As shown in Figure 12, the excavator 150 comprises a body 12 and a pair of running gears 16. The body 12 comprises a lower body 14 and an upper body 154. The upper body 154 is located on the opposite side of the lower body 14 from the ground G. The upper body 154 can pivot left and right relative to the lower body 14 about an axis extending approximately in the Z direction. In the following description, the pivot angle of the upper body 154 is assumed to be zero degrees. The pair of running gears 16 are located on both the left and right sides of the lower body 14. The configuration of the lower body 14 and the running gears 16 is the same as in the above embodiment, so the description is omitted. The way in which the front, rear, left, right, up, and down directions of the excavator 150 are defined is the same as in the above embodiment.

[0151] The upper body 154 comprises a main section 154A and a support wall section 154B. In Figure 12, a dotted line shows a convenient boundary between the main section 154A and the support wall section 154B. However, the main section 154A and the support wall section 154B are a single unit, and in reality, there is no boundary between them. The main section 154A is rectangular in shape as a whole. However, the front portion of the upper surface of the main section 154A is inclined downwards. The support wall section 154B is located on the front side relative to the main section 154A. The support wall section 154B is located on the lower portion of the main section 154A. The support wall section 154B is rectangular in shape. Both the upper and lower surfaces of the support wall section 154B are approximately parallel to the ground G. As a result of the support wall portion 154B being located in the lower part of the main portion 154A, the upper surface of the support wall portion 154B is located lower than the upper surface of the main portion 154A.

[0152] The main section 154A includes a housing section 154C. In Figure 12, the housing section 154C is shown by a thick solid line. The housing section 154C is located on the rear part of the upper surface of the main section 154A. The housing section 154C is a structural part for arranging the battery 98 to be mounted on the excavator 150. The housing section 154C is, for example, a recess that conforms to the shape of the battery 98.

[0153] The excavator 150 is equipped with a first mechanism 41. The first mechanism 41, as in the above embodiment, includes a first drive unit 51, a second drive unit 52, a third drive unit 53, a first boom 61, a first arm 62, and a first attachment 63. The first mechanism 41 will be briefly described below, mainly focusing on the parts that differ from the above embodiment.

[0154] The first drive unit 51 is located on the upper side with respect to the support wall 154B. Although detailed illustrations are omitted, the first drive unit 51 is connected to the upper surface of the support wall 154B. The first drive unit 51 outputs torque centered on the first rotation axis 51J, which is approximately perpendicular to the reference axis K. The reference axis K extends approximately in the Z direction, passing through the upper and lower surfaces of the support wall 154B. That is, the reference axis K extends vertically across the vehicle body 12. The first rotation axis 51J extends approximately in the Y direction.

[0155] The first boom 61 extends from the first drive unit 51. The first boom 61 is bent in the middle. The first end 61A of the first boom 61 is located on the first rotation axis 51J. The first end 61A of the first boom 61 is connected to the first drive unit 51. The first boom 61 rotates about the first rotation axis 51J in response to torque from the first drive unit 51. Similar to the above embodiment, a plan view of the excavator 150 facing in a direction parallel to the first rotation axis 51J is referred to as a specific plan view. In the specific plan view, the first boom 61 is rotatable both forward and backward with respect to the reference axis K. More specifically, in the specific plan view, the first boom 61 is rotatable forward and backward across a reference half-line extending upward from the first rotation axis 51J along the reference axis K. For example, the first boom 61 can rotate more than 90 degrees forward with respect to a reference half-line in a specific plan view. For example, the first boom 61 can rotate up to about 45 degrees backward with respect to a reference half-line in a specific plan view. The range of backward rotation of the first boom 61 is determined from the viewpoint of avoiding interference between the first boom 61 and the main part 154A of the upper body 154 when the first boom 61 rotates backward.

[0156] As described above, the first end 61A of the first boom 61 is connected to the support wall 154B via the first drive unit 51. The first drive unit 51 is located on the upper surface of the support wall 154B. In consideration of the arrangement of the first drive unit 51, the first end 61A of the first boom 61, that is, the connection point between the first boom 61 and the upper body 154, is located forward of the center of the upper body 154 in the X direction. In other words, the first end 61A of the first boom 61 is located on one side of the center of the upper body 154 in a direction perpendicular to both the reference axis K and the first rotation axis 51J.

[0157] The second drive unit 52 is connected to the second end 61B of the first boom 61, which is opposite to the first end 61A. The second drive unit 52 outputs torque around the second rotation axis 52J. The second rotation axis 52J is located at a different position from the first rotation axis 51J and extends approximately parallel to the first rotation axis 51J. The second rotation axis 52J passes through the second end 61B of the first boom 61.

[0158] The first arm 62 extends linearly from the second drive unit 52. The first end 62A of the first arm 62 is connected to the second drive unit 52. In other words, the first end 62A of the first arm 62 is connected to the second end 61B of the first boom 61 via the second drive unit 52. The first arm 62 rotates about the second rotation axis 52J in response to torque from the second drive unit 52. In a specific plan view, the first arm 62 can rotate 360 ​​degrees to one side and the other side with respect to the first virtual straight line 41E connecting the first rotation axis 51J and the second rotation axis 52J. In other words, in a specific plan view, the first arm 62 can perform the following rotational movements. The first arm 62 can rotate to one side and the other side along the first virtual straight line 41E, crossing a half-line that extends from the second rotation axis 52J in the opposite direction from the first rotation axis 51J. Furthermore, the first arm 62 is rotatable on the first virtual straight line 41E, straddling a specific half-line 41V that extends from the second rotation axis 52J towards the first rotation axis 51J.

[0159] The third drive unit 53 is connected to the second end 62B of the first arm 62, which is opposite to the first end 62A. The third drive unit 53 outputs torque around the third rotation axis 53J. The third rotation axis 53J extends approximately parallel to the first rotation axis 51J, but at a different position from the first rotation axis 51J and the second rotation axis 52J. The third rotation axis 53J passes through the second end 62B of the first arm 62.

[0160] The first attachment 63 is connected to the third drive unit 53. That is, the first attachment 63 is connected to the second end 62B of the first arm 62 via the third drive unit 53. Similar to the excavator 110 in Figures 8 to 10, the first attachment 63 is located on the opposite side of the first boom 61 from the first arm 62 with respect to the direction parallel to the first rotation axis 51J. The first attachment 63 has a configuration in which one of the two buckets in the above embodiment is eliminated. That is, the first attachment 63 is a bucket comprising a bucket body 67 having an opening 67A and claws 68 protruding from the opening edge of the bucket body 67. The orientation of the opening 67A of the bucket body 67 is determined for cutting. The first attachment 63 rotates about the third rotation axis 53J in response to torque from the third drive unit 53. In a specific planar view, the first attachment 63 can rotate 360 ​​degrees in both directions with respect to the second virtual straight line 41F connecting the second rotation axis 52J and the third rotation axis 53J.

[0161] The excavator 150 is equipped with a control device 45. The control device 45 controls the first mechanism 41 and other components. The control device 45 controls the first drive unit 51, the second drive unit 52, the third drive unit 53, and other components in response to command signals transmitted from the controller 46. The controller 46 and the excavator 150 constitute an excavator system 47.

[0162] The control device 45 is capable of performing an installation process. The installation process involves installing a battery 98, which is not yet installed in the excavator 150, into the excavator 150. The memory pre-stores a program for performing the installation process. The CPU executes this program, thereby enabling the control device 45 to perform the installation process. The excavator 150 is pre-installed with multiple batteries 98. While the installation process is in progress, the control device 45 operates each drive unit of the first mechanism 41 using power supplied from the batteries 98 already installed in the excavator 150.

[0163] The following describes the setup process and the preparation state of the first mechanism 41 before the start of the setup process. In the preparation state, the first boom 61 is positioned forward with respect to the reference axis K. That is, the second end 61B of the first boom 61 is positioned forward of the first end 61A. At the same time, the second end 61B of the first boom 61 is positioned upward of the first end 61A. The first arm 62 is positioned downward of the second end 61B of the first boom 61. The second end 62B of the first arm 62 is positioned both downward and forward of the first end 62A. The first attachment 63 is located near the ground G. A battery 98 is attached to the claw 68 of the first attachment 63.

[0164] Now, let's assume that when the first mechanism 41 is in a ready state, the controller 46 sends a signal to the control device 45 to start the installation process. In response to this signal, the control device 45 starts the installation process. Once the control device 45 starts the installation process, it operates the first mechanism 41 as follows. The operation of the first mechanism 41 will be described below assuming a specific plan view. The control device 45 rotates the first boom 61 backward with respect to the reference axis K, as shown by arrow 61M in Figure 13. Accordingly, the second end 61B of the first boom 61 moves upward compared to when it was in the ready state. As the control device 45 rotates the first boom 61, it rotates the first arm 62 from the front to the rear, crossing a specific half-line 41V, as shown by arrow 62M in Figure 13. Furthermore, the control device 45 moves the second end 62B of the first arm 62 backward relative to the first end 62A. At this time, the second end 62B of the first arm 62 is positioned downward relative to the first end 61A. Simultaneously, the first attachment 63 is positioned approximately directly above the housing section 154C in the upper body 154. After this, the control device 45 places the battery 98 in the housing section 154C by fine-tuning the rotational positions of the first boom 61, the first arm 62, and the first attachment 63. After this, the connection between the battery 98 and the claw 68 of the first attachment 63 is released, either automatically or manually.

[0165] The control device 45 is capable of performing a release process. The release process is the process of removing the battery 98 from the excavator 150. The memory has a program for performing the release process stored in advance. The CPU executes this program, and the control device 45 performs the release process. While the release process is being performed, the control device 45 operates each drive device of the first mechanism 41 using power supplied from another battery 98 already installed in the excavator 150.

[0166] Assume that the battery 98 to be removed is currently installed in the housing 154C. Also, as shown in Figure 13, the battery 98 is connected to the claw 68 of the first attachment 63. In this state, assume that the controller 46 sends a signal to the control device 45 to initiate the release process. In response to this signal, the control device 45 begins the release process. Once the release process begins, the control device 45 causes the first mechanism 41 to perform the reverse operation compared to the installation process. Specifically, the control device 45 rotates the first arm 62 forward relative to the specific half-line 41V. Simultaneously, the control device 45 rotates the first boom 61 forward relative to the reference axis K. Then, the control device 45 moves the first boom 61, the first arm 62, and the first attachment 63 to the ready position. When the first mechanism 41 is in the ready position, the control device 45 terminates the release process.

[0167] As described above, the control device 45 can switch the orientation of the first mechanism 41 by performing an installation process and a release process. Specifically, the control device 45 can switch the orientation of the first mechanism 41 in a specific plan view to either the first orientation, which is the ready state, or the second orientation, in which the battery 98 is installed in the housing 154C. As shown in Figure 12, in the first orientation, in a specific plan view, the first boom 61 is rotated forward with respect to the reference axis K, and the third rotation axis 53J is located forward and downward with respect to the second rotation axis 52J. In other words, in the first orientation, in a direction perpendicular to both the first rotation axis 51J and the reference axis K, the third rotation axis 53J is located on the opposite side of the second rotation axis 52J from the first rotation axis 51J. On the other hand, as shown in Figure 13, in the second posture, the first boom 61 is rotated rearward with respect to the reference axis K in a specific plan view, and the third rotation axis 53J is located rearward and downward with respect to the second rotation axis 52J. In other words, in the second posture, the third rotation axis 53J is located on the opposite side of the second rotation axis 52J from the first rotation axis 51J in a direction perpendicular to both the first rotation axis 51J and the reference axis K. By being able to switch between these postures, the first mechanism 41 can operate over a wide range in both the forward and rearward directions with respect to the reference axis K. This enables the installation and removal of the battery 98 in the excavator 150.

[0168] Furthermore, when the control device 45 rotates the first arm 62 during the switching between the first and second postures, it moves the first arm 62 forward and backward across a specific half-line 41V. As a comparative example of this configuration, suppose the first arm 62 is moved forward and backward across a half-line extending from the second rotation axis 52J to the opposite side of the first rotation axis 51J. In this case, when the first arm 62 moves, the second end 62B of the first arm 62 and thus the first attachment 63 will pass on the upper side of the first end 61A of the first arm 62 and thus the first boom 61. Consequently, the battery 98 attached to the first attachment 63 will be transported at a considerably high position relative to the upper surface of the upper body 154. In this case, if the battery 98 were to detach from the first attachment 63 and fall, there is a risk that a large collision load would act on the battery 98 and the upper body 154. In this regard, as described above, by moving the first arm 62 back and forth across a specific semi-linear 41V, the battery 98 can be transported in a position close to the upper surface of the upper body 154. Therefore, even if the battery 98 were to detach from the first attachment 63 and fall, the impact load acting on the battery 98 and the upper body 154 would be extremely small.

[0169] An example of a case in which the shape of the vehicle body 12, the mounting manner of the first drive unit 51 to the vehicle body 12, and the arrangement of the connection points of the first boom 61 to the vehicle body 12 are changed from the above embodiment will be explained using Figure 15. In the following, the parts of the excavator 170 shown in Figure 15 that differ from the above embodiment will be mainly explained, and the explanation of parts that overlap with the above embodiment will be omitted or simplified as appropriate. In Figure 15, parts that function the same or substantially the same as those in Figures 1 to 13 are denoted by the same reference numerals as in Figures 1 to 13.

[0170] As shown in Figure 15, the excavator 170 comprises a body 12 and a pair of running gears 16. The body 12 comprises a lower body 14 and an upper body 172. The upper body 172 is located on the opposite side of the ground G from the lower body 14. The pair of running gears 16 are located on both the left and right sides of the lower body 14. The configuration of the lower body 14 and the running gears 16 is the same as in the above embodiment, so a description is omitted. The way in which the front, rear, left, right, up, and down directions of the excavator 170 are defined is the same as in the above embodiment.

[0171] The upper body 172 comprises a main section 174, a first support wall section 176, and a second support wall section 178. The main section 174 is rotatable left and right relative to the lower body 14 about an axis extending substantially in the Z direction. In the following description, the rotation angle of the main section 174 is assumed to be zero degrees. The first support wall section 176 and the second support wall section 178 are provided symmetrically in the front-to-back direction with respect to the main section 174. The first support wall section 176 is located on the front side relative to the main section 174. The first support wall section 176 protrudes forward from the main section 174. The first support wall section 176 is, for example, rectangular parallelepiped. Both the upper and lower surfaces of the first support wall section 176 are substantially parallel to the ground G. The second support wall section 178 is located on the rear side relative to the main section 174. The second support wall portion 178 protrudes from the main portion 174 toward the rear. The shape of the second support wall portion 178 and the orientation of each wall surface in the second support wall portion 178 are substantially the same as those of the first support wall portion 176. Furthermore, in the Y and Z directions, the second support wall portion 178 is positioned substantially the same as that of the first support wall portion 176.

[0172] The excavator 170 is equipped with a first working mechanism 181. The first working mechanism 181 is located on the front side of the main body 174 of the upper body 172. The basic configuration of the first working mechanism 181 is the same as the first mechanism 41 in the above embodiment. That is, the first working mechanism 181 is a mechanism consisting of a first drive unit 51, a second drive unit 52, a third drive unit 53, a first boom 61, a first arm 62, and a first attachment 63 as a set. The first working mechanism 181 will be briefly described below, mainly focusing on the parts that differ from the first mechanism 41 in the above embodiment.

[0173] The first drive unit 51 is connected to the first support wall 176. The first drive unit 51 outputs torque centered on the first rotation axis 51J, which is substantially perpendicular to the first reference axis K1. The first reference axis K1 extends substantially in the Z direction, passing through the upper and lower surfaces of the first support wall 176. That is, the first reference axis K1 extends vertically across the vehicle body 12. The first rotation axis 51J extends substantially in the Y direction.

[0174] The first boom 61 extends linearly forward from the first drive unit 51. The first end 61A of the first boom 61 is located on the first rotation axis 51J. The first end 61A of the first boom 61 is connected to the first drive unit 51. That is, the first end 61A of the first boom 61 is connected to the first support wall 176 via the first drive unit 51. The first boom 61 rotates about the first rotation axis 51J in response to torque from the first drive unit 51. Similar to the above embodiment, a plan view of the excavator 170 facing in a direction parallel to the first rotation axis 51J is referred to as a specific plan view. In the specific plan view, the first boom 61 is rotatable both forward and backward with respect to the first reference axis K1. In detail, the first boom 61 is rotatable in the forward and backward directions in a specific plan view, straddling a first reference half-line that extends upward from the first rotation axis 51J along the first reference axis K1. For example, the first boom 61 is rotatable by more than 90 degrees forward with respect to the first reference half-line in a specific plan view.

[0175] The second drive unit 52 is connected to the second end 61B of the first boom 61, which is opposite to the first end 61A. The second drive unit 52 outputs torque around the second rotation axis 52J. The second rotation axis 52J is located at a different position from the first rotation axis 51J and extends approximately parallel to the first rotation axis 51J. The second rotation axis 52J passes through the second end 61B of the first boom 61.

[0176] The first arm 62 extends linearly forward from the second drive unit 52. The first end 62A of the first arm 62 is connected to the second drive unit 52. In other words, the first end 62A of the first arm 62 is connected to the second end 61B of the first boom 61 via the second drive unit 52. The first arm 62 rotates about the second rotation axis 52J in response to torque from the second drive unit 52. In a specific plan view, the first arm 62 is rotatable in both directions relative to the first virtual straight line 41E connecting the first rotation axis 51J and the second rotation axis 52J. For example, the first arm 62 is rotatable approximately 360 degrees in both directions relative to the first virtual straight line 41E.

[0177] The third drive unit 53 is connected to the second end 62B of the first arm 62, which is opposite to the first end 62A. The third drive unit 53 outputs torque around the third rotation axis 53J. The third rotation axis 53J extends approximately parallel to the first rotation axis 51J, but at a different position from the first rotation axis 51J and the second rotation axis 52J. The third rotation axis 53J passes through the second end 62B of the first arm 62.

[0178] The first attachment 63 is connected to the third drive unit 53. That is, the first attachment 63 is connected to the second end 62B of the first arm 62 via the third drive unit 53. The first attachment 63 is the same as the one described in Figure 12 for the excavator 150. That is, the first attachment 63 is a box-shaped bucket. The first attachment 63 rotates about the third rotation axis 53J in response to torque from the third drive unit 53. In a specific plan view, the first attachment 63 is rotatable in both directions relative to the second virtual straight line 41F connecting the second rotation axis 52J and the third rotation axis 53J. For example, the first attachment 63 is rotatable approximately 360 degrees in both directions relative to the second virtual straight line 41F. Note that the first attachment 63 is not limited to a bucket. Depending on the task, an appropriate device, mechanism, or tool may be adopted as the first attachment 63. If a device that does not require rotation is adopted as the first attachment 63, the third drive device 53 may be abolished and the first attachment 63 may be directly connected to the first arm 62.

[0179] The excavator 170 is equipped with a second working mechanism 182. The second working mechanism 182 is located on the rearward side of the main part 174 of the upper body 172. That is, in a specific plan view relating to the first working mechanism 181, the first working mechanism 181 and the second working mechanism 182 are located on one side and the other side of the center of the main part 174 of the upper body 172 in the X direction. The X direction is perpendicular to both the first rotation axis 51J and the first reference axis K1 of the first working mechanism 181. With respect to both the Y and Z directions, the second working mechanism 182 is positioned in approximately the same position as the first working mechanism 181.

[0180] The second working mechanism 182 has a configuration in which the front and back of the first working mechanism 181 are reversed. That is, the second working mechanism 182 is a mechanism consisting of a first drive unit 51, a second drive unit 52, a third drive unit 53, a first boom 61, a first arm 62, and a first attachment 63 as a set. The first drive unit 51 of the second working mechanism 182 is connected to the second support wall 178. The first drive unit 51 outputs torque centered on the first rotation axis 51J, which is approximately perpendicular to the second reference axis K2. The second reference axis K2 extends approximately in the Z direction, penetrating the upper and lower surfaces of the second support wall 178. The second reference axis K2 extends approximately parallel to the first reference axis K1 at a different position from the first reference axis K1. The first rotation axis 51J extends approximately in the Y direction, similar to the case of the first working mechanism 181. In a specific plan view, the first boom 61, receiving torque from the first drive unit 51, is rotatable in the forward and backward directions, straddling a second reference half-line that extends upward from the first rotation axis 51J along the second reference axis K2. For example, in a specific plan view, the first boom 61 can rotate more than 90 degrees backward with respect to the second reference half-line. The manner in which the components of the second working mechanism 182 are connected is the same as that of the first working mechanism 181. Therefore, further explanation of the second working mechanism 182 is omitted.

[0181] The excavator 170 is equipped with a control device 45. The control device 45 controls both the drive units of the first working mechanism 181 and the drive units of the second working mechanism 182. The control device 45 can control the drive units of the first working mechanism 181 and the drive units of the second working mechanism 182 individually. In other words, the control device 45 can operate the drive units of the first working mechanism 181 and the drive units of the second working mechanism 182 synchronously or separately. The control device 45 controls the first working mechanism 181 and the second working mechanism 182 in response to command signals transmitted from the controller 46. The controller 46 and the excavator 170 constitute an excavator system 47.

[0182] In the excavator 170, working mechanisms are provided on both the front and rear sides of the upper body 172. In this case, the excavator 170 can perform work on the front side of the upper body 172 by using the first working mechanism 181. In addition, the excavator 170 can perform work on the rear side of the upper body 172 by using the second working mechanism 182. Therefore, since the excavator 170 can perform work on the upper body 172 on both the front and rear sides, the working range of the excavator 170 is widened.

[0183] Here, let's consider a comparative example of the excavator 170 in which the second working mechanism 182 is eliminated from the first working mechanism 181. In this comparative example, because the second working mechanism 182 is eliminated, the weight of the rear part of the excavator 170 becomes smaller than the weight of the front part. In this case, since the front and rear weights of the excavator 170 become uneven, it is necessary to provide a counterweight in the rear part of the excavator 170. The counterweight is a weight used to balance the weight of the excavator 170.

[0184] In this respect, in the configuration of this embodiment, since there are working mechanisms at both the front and rear of the excavator 170, the weight of the excavator 170 becomes approximately uniform at the front and rear due to these two working mechanisms. Therefore, a counterweight is not required.

[0185] With respect to the excavator 170 shown in Figure 15, it is not essential that the first working mechanism 181 and the second working mechanism 182 have identical configurations. For example, the first attachment 63 used in the first working mechanism 181 and the second working mechanism 182 may be different, or the shape or length of the first booms 61 may differ. Even in this case, if working mechanisms are provided on both the front and rear sides of the upper body 172, the range of work performed by the excavator 170 will be widened. Furthermore, even if the configurations of the first working mechanism 181 and the second working mechanism 182 are different, if the first working mechanism 181 and the second working mechanism 182 are configured so that their weights are approximately the same, a counterweight will not be necessary.

[0186] Furthermore, if the weights of the first working mechanism 181 and the second working mechanism 182 are different, the following configuration may be adopted. That is, a vertical movement mechanism for changing the vertical position of the first drive unit 51 is provided between the first support wall 176 and the first drive unit 51 of the first working mechanism 181. Similarly, a vertical movement mechanism for changing the vertical position of the first drive unit 51 is provided between the second support wall 178 and the first drive unit 51 of the second working mechanism 182. By utilizing these vertical movement mechanisms, the overall height of the first working mechanism 181 and the overall height of the second working mechanism 182 may be made different. For example, in addition to these height differences, the balance of the excavator 170 can be achieved without providing a counterweight by changing the lengths of the first booms 61 or the first arms 62 of the first working mechanism 181 and the second working mechanism 182.

[0187] Furthermore, the arrangement of the first working mechanism 181 and the second working mechanism 182 is not limited to the example shown in Figure 15. For example, the positions of the first working mechanism 181 and the second working mechanism 182 may differ in at least one of the Z and Y directions. For example, as shown in Figure 14, when the excavator 170 is viewed facing the Z direction, the first rotation axis 51J related to the first drive unit 51 of the first working mechanism 181 and the second working mechanism 182 may be arranged such that they intersect. The two sets of working mechanisms only need to be arranged such that the following arrangement conditions are satisfied when the excavator 170 is viewed from above in a direction parallel to the first rotation axis 51J of a particular working mechanism among the two sets of working mechanisms. The arrangement condition is that, in a direction perpendicular to both the first rotation axis 51J and the reference axis for the specific working mechanism among the two sets of working mechanisms, the two sets of working mechanisms are located on one side and the other side of the center of the vehicle body 12. The direction perpendicular to both the first rotation axis 51J and the reference axis for the specific working mechanism may not be the X direction.

[0188] When two sets of working mechanisms are provided, the first boom 61, the first arm 62, and the first attachment 63 may be operated hydraulically. [Explanation of Symbols]

[0189] 10, 110, 150, 170... Excavators 12... Vehicle body 23…Top surface 25…Connecting member 30…Main slewing device 31…First slewing device 32...Second slewing device 51…First drive unit 52...Second drive unit 53…Third drive unit 61…First boom 62...First Arm 63…First Attachment 65A...First bucket 65B...Second bucket 67...Bucket body 67A…Aperture 68… Nails 71...Second boom 72... Second Arm 73…Second attachment

Claims

1. A drive system that outputs torque centered on a rotation axis perpendicular to a reference axis extending vertically along the drivable vehicle body, The vehicle body is connected to a boom that rotates about the rotation axis in response to torque from the drive unit, When viewed in a direction parallel to the rotation axis, the boom is rotatable in both directions relative to the reference axis. Construction machinery.

2. When viewed in a direction parallel to the rotation axis, the boom is rotatable by 90 degrees or more to one side and 90 degrees or more to the other side with respect to the reference axis. The construction machine according to claim 1.

3. When the aforementioned drive device is designated as the first drive device and the aforementioned rotation axis is designated as the first rotation axis, A second drive unit that outputs torque about a second rotation axis which is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point to the vehicle body, An arm is connected to the end of the boom opposite to the connection point to the vehicle body, and rotates about the second rotation axis in response to torque from the second drive unit, A third drive device that outputs torque about a third rotation axis which is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point with the boom, The attachment is connected to the end of the arm opposite to the connection point to the boom, and rotates about the third rotation axis in response to torque from the third drive device, When viewed in a direction parallel to the first axis of rotation, The arm is rotatable in both directions with respect to a virtual straight line connecting the first rotation axis and the second rotation axis. The attachment is rotatable in both directions with respect to a virtual straight line connecting the second axis of rotation and the third axis of rotation. The construction machine according to claim 1.

4. When viewed in a direction parallel to the aforementioned axis of rotation, The vehicle body has an inclined surface that slopes upward so as it approaches the reference axis, and a top surface that is connected to the uppermost end of the inclined surface and is perpendicular to the reference axis. The boom is connected to the top surface. The construction machine according to claim 2.

5. A slewing device that outputs torque centered on a pivot axis parallel to the aforementioned reference axis, The vehicle body and the boom are interposed, and the connecting member rotates about the pivot axis in response to torque from the pivoting device, The connecting member is rotatable around the entire circumference of the pivot axis. The construction machine according to claim 1 or 2.

6. The vehicle body is configured in a frustoconical shape, where the cross-sectional area perpendicular to the reference axis decreases as it moves upward. The boom is connected to the top surface, which is the upper side of the vehicle body. The construction machine according to claim 5.

7. The connection point of the boom to the vehicle body is located in the center of the vehicle body in a direction perpendicular to both the rotation axis and the reference axis. The construction machine according to claim 1.

8. When the aforementioned drive device is designated as the first drive device and the aforementioned rotation axis is designated as the first rotation axis, A second drive unit that outputs torque about a second rotation axis which is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point to the vehicle body, An arm is connected to the end of the boom opposite to the connection point to the vehicle body, and rotates about the second rotation axis in response to torque from the second drive unit, A third drive device that outputs torque about a third rotation axis which is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point with the boom, The attachment is connected to the end of the arm opposite to the connection point to the boom, and rotates about the third rotation axis in response to torque from the third drive device, The aforementioned attachment has two buckets having openings, The openings of the two buckets face in opposite directions and are aligned in the circumferential direction around the third rotation axis. The construction machine according to claim 1.

9. The bucket comprises a box-shaped bucket body having an opening, and claws protruding from the opening edge of the bucket body. When viewed in a direction parallel to the third axis of rotation, in each of the buckets, the claws protrude from the position furthest from the third axis of rotation on the opening edge of the bucket body. When viewed in a direction parallel to the third axis of rotation, the rotational trajectory of the protruding end of the claw on one bucket and the rotational trajectory of the protruding end of the claw on the other bucket overlap when the attachment rotates once around the third axis of rotation while the arm is in a fixed position. The construction machine according to claim 8.

10. When the aforementioned drive device is designated as the first drive device and the aforementioned rotation axis is designated as the first rotation axis, A second drive unit that outputs torque about a second rotation axis which is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point to the vehicle body, An arm is connected to the end of the boom opposite to the connection point to the vehicle body, and rotates about the second rotation axis in response to torque from the second drive unit, A third drive device that outputs torque about a third rotation axis which is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point with the boom, The attachment is connected to the end of the arm opposite to the connection point to the boom, and rotates about the third rotation axis in response to torque from the third drive device, When viewed in a direction parallel to the first axis of rotation, The arm is rotatable to the extent that the third rotation axis is located on a half-line extending from the second rotation axis and intersecting the first rotation axis. The construction machine according to claim 1.

11. When the aforementioned drive device is designated as the first drive device and the aforementioned rotation axis is designated as the first rotation axis, A second drive unit that outputs torque about a second rotation axis which is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point to the vehicle body, An arm is connected to the end of the boom opposite to the connection point to the vehicle body, and rotates about the second rotation axis in response to torque from the second drive unit, A third drive device that outputs torque about a third rotation axis which is parallel to the first rotation axis and passes through the end of the arm opposite to the connection point with the boom, An attachment is connected to the end of the arm opposite to the connection point to the boom, and rotates about the third rotation axis in response to torque from the third drive device, The system comprises a control device that controls the first drive unit, the second drive unit, and the third drive unit, The control device is capable of switching between a first posture in which, when viewed from a direction parallel to the first rotation axis, the boom is rotated to one side with respect to the reference axis, and the third rotation axis is located on the opposite side of the second rotation axis from the first rotation axis in a direction perpendicular to both the first rotation axis and the reference axis, and a second posture in which, when viewed from a direction parallel to the first rotation axis, the boom is rotated to the other side with respect to the reference axis, and the third rotation axis is located on the opposite side of the second rotation axis from the first rotation axis in a direction perpendicular to both the first rotation axis and the reference axis, and when switching between the first posture and the second posture, the arm is rotated across a half-line extending from the second rotation axis and intersecting the first rotation axis when viewed from a direction parallel to the first rotation axis. The construction machine according to claim 1.

12. A first slewing device that outputs torque around a first slewing axis extending vertically above and below the drivable vehicle body, A boom connected to the vehicle body, which rotates about the first pivot axis in response to torque from the first pivot device, A second slewing device that outputs torque around a second slewing axis which is parallel to the first slewing axis and passes through the end of the boom opposite to the connection point to the vehicle body, An arm is connected to the end of the boom opposite to the connection point to the vehicle body, and rotates about the second pivot axis in response to torque from the second pivot device, The arm comprises an attachment connected to the end opposite to the connection point with respect to the boom. Construction machinery.

13. The attachment is an electrically operated telescopic device that extends and retracts in a direction along a motion axis parallel to the first pivot axis. The construction machine according to claim 12.

14. A first drive unit that outputs torque centered on a first rotation axis perpendicular to a reference axis extending vertically from the drivable vehicle body, A boom connected to the vehicle body, which rotates about a first rotation axis in response to torque from the first drive unit, A second drive unit that outputs torque about a second rotation axis which is parallel to the first rotation axis and passes through the end of the boom opposite to the connection point to the vehicle body, An arm is connected to the end of the boom opposite to the connection point to the vehicle body, and rotates about the second rotation axis in response to torque from the second drive unit, The arm comprises an attachment connected to the end opposite to the connection point with respect to the boom, When the first drive unit, the boom, the second drive unit, the arm, and the attachment are combined to form one working mechanism, there are two sets of the working mechanisms, When viewed in a direction parallel to the first rotation axis of a specific working mechanism among the two sets of working mechanisms, the two sets of working mechanisms are located on one side and the other side of the center of the vehicle body in a direction perpendicular to both the first rotation axis and the reference axis with respect to the specific working mechanism. Construction machinery.

15. A boom is connected to the vehicle body so as to be rotatable about a rotation axis perpendicular to a reference axis extending vertically from the vehicle body, and torque can be output about the rotation axis. When viewed in a direction parallel to the rotation axis, the boom can be rotated in both directions relative to the reference axis. The drive system for construction machinery.

16. When viewed in a direction parallel to the rotation axis, the boom can be rotated by 90 degrees or more to one side and 90 degrees or more to the other side with respect to the reference axis. The drive device for a construction machine according to claim 15.

17. A first drive unit capable of outputting torque around the first rotation axis is provided for a boom that is rotatably connected to the vehicle body so as to a first rotation axis perpendicular to a reference axis extending vertically from the vehicle body, and A second drive unit is provided that can output torque about the second rotation axis to an arm that is connected to the end of the boom opposite to the connection point to the vehicle body, and that passes through the said end and is rotatable about a second rotation axis parallel to the first rotation axis. The system includes a third drive device capable of outputting torque about the third rotation axis to an attachment that is connected to the end of the arm opposite to the connection point to the boom, and which passes through the said end and is rotatable about a third rotation axis parallel to the first rotation axis, When viewed in a direction parallel to the first axis of rotation, The first drive device is capable of rotating the boom on both one side and the other side with respect to the reference axis. The second drive device is capable of rotating the arm in both directions with respect to a virtual straight line connecting the first rotation axis and the second rotation axis, The third drive device is capable of rotating the attachment on both sides with respect to a virtual straight line connecting the second rotation axis and the third rotation axis. A drive unit for construction machinery.

18. A drive device is provided that can output torque around a rotation axis perpendicular to a reference axis extending vertically above and below the drivable vehicle body, and that can rotate the boom, which is connected to the vehicle body so as to be rotatable around the rotation axis, and that can rotate the boom in both directions relative to the reference axis when viewed in a direction parallel to the rotation axis. The vehicle body and the boom are interposed, and the slewing device is capable of outputting torque around the slewing axis to a connecting member that is rotatable about a slewing axis parallel to the reference axis, and is capable of rotating the connecting member around the slewing axis over its entire circumference. A drive unit for construction machinery.

19. A first slewing device that outputs torque around the first slewing axis to a boom that is rotatably connected to the vehicle body so as to the first slewing axis that extends vertically above and below the vehicle body, The system includes a second slewing device that outputs torque around the second slewing axis to an arm that is connected to the end of the boom opposite to the connection point to the vehicle body, and which passes through the end and is rotatable around a second slewing axis parallel to the first slewing axis. A drive unit for construction machinery.

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