Attachments and electric excavators

Abstract

To assist drilling operations so that a targeted hole is formed in an object to be drilled.SOLUTION: An attachment is attached to an electric excavator. An electric excavator comprises a motor housing that houses a motor, a handle housing located behind the motor housing and having a grip portion provided with a trigger switch for activating the motor, a gear housing located in front of the motor housing to accommodate gears, and a rotation output section protruding downward from the gear housing to which a drill bit is attached. The attachment includes an auxiliary pole arranged along the vertical direction at a position adjacent to the drill bit.SELECTED DRAWING: Figure 23

Description

Technical Field

[0001] The technology disclosed in this specification relates to an attachment and an electric excavator.

Background Art

[0002] In the technical field related to electric excavators, an electric tool that rotates an earth auger bit to excavate the ground, as disclosed in Patent Document 1, is known. The electric tool disclosed in Patent Document 1 forms a hole in the ground by rotating the earth auger bit while being held by an operator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When an electric excavator performs an excavation operation on an excavation target while being held by an operator, it may be difficult to form a target hole in the excavation target. There is a demand for a technology that can assist the excavation operation so that the target hole can be formed in the excavation target.

[0005] The technology disclosed in this specification aims to assist the excavation operation so that a target hole is formed in an excavation target when excavating the excavation target with a portable electric excavator.

Means for Solving the Problems

[0006] This specification discloses an attachment to be mounted on an electric drill. The electric drill may include a motor housing that houses a motor, a handle housing that is disposed on the rear side of the motor housing and has a grip portion provided with a trigger switch for starting the motor, a gear housing that is disposed on the front side of the motor housing and houses gears, and a rotary output portion that protrudes downward from the gear housing and to which a drill bit is attached. The attachment may include an auxiliary pole that is disposed along the vertical direction at a position adjacent to the drill bit.

Advantages of the Invention

[0007] According to the technology disclosed in this specification, the drilling operation is assisted so that a target hole is formed in the object to be drilled.

Brief Description of the Drawings

[0008]

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DETAILED DESCRIPTION OF THE INVENTION

[0009] In one or more embodiments, the attachment is mounted on an electric drill. The electric drill may include a motor housing that houses a motor, a handle housing that is disposed on the rear side of the motor housing and has a grip portion provided with a trigger switch for starting the motor, a gear housing that is disposed on the front side of the motor housing and houses gears, and a rotary output portion that protrudes downward from the gear housing and to which a drill bit is attached. The attachment may include an auxiliary pole that is disposed along the vertical direction at a position adjacent to the drill bit.

[0010] In the above configuration, the auxiliary pole can assist the drilling operation so that a target hole is formed in the drilling target. A hole is formed in the drilling target by the rotation of the drill bit. The target hole is formed in the drilling target by the auxiliary pole contacting the surface of the drilling target around the hole formed by the drill bit.

[0011] In one or more embodiments, the lower end portion of the auxiliary pole may be disposed above the lower end portion of the drill bit.

[0012] In the above configuration, by disposing the lower end portion of the auxiliary pole above the lower end portion of the drill bit, a hole having a target depth is formed in the drilling target. The vertical distance between the lower end portion of the auxiliary pole and the lower end portion of the cutting edge of the drill bit is determined as the target depth of the hole, and the drilling operation is performed until the lower end portion of the auxiliary pole contacts the surface of the drilling target around the hole formed by the drill bit, whereby a hole having the target depth is formed in the drilling target.

[0013] In one or more embodiments, the attachment may include an auxiliary handle that is detachably attached to the gear housing, and a holding member that is detachably attached to at least a part of the auxiliary handle. The auxiliary pole may be held by the holding member.

[0014] In the above configuration, when the auxiliary handle is grasped by the operator's hand, the excavation work can be smoothly carried out. Since the auxiliary pole is supported by the auxiliary handle via the holding member, the operator can form a hole at the target depth in the object to be excavated while holding the auxiliary handle by hand.

[0015] In one or more embodiments, the holding member may have a holding mechanism for detachably holding the auxiliary pole. The holding mechanism may include a clamp portion disposed at least partially around the auxiliary pole and a lever connected to the clamp portion via a hinge. When the lever is rotated in the fastening direction, the auxiliary pole may be fixed to the clamp portion. When the lever is rotated in the relaxation direction, the fixing of the auxiliary pole by the clamp portion may be released.

[0016] In the above configuration, when the lever is rotated in the fastening direction, the vertical position of the auxiliary pole with respect to the holding member is fixed. When the lever is rotated in the relaxation direction, the vertical position of the auxiliary pole with respect to the holding member is adjusted.

[0017] In one or more embodiments, the auxiliary handle may include a handle joint fixed to the gear housing and a handle fixed to the handle joint. The holding member may be fixed to the handle joint.

[0018] In the above configuration, the holding member is fixed to the gear housing via the handle joint. The operator can hold the handle by hand.

[0019] In one or more embodiments, the handle joint may include a left handle joint fixed to the left part of the gear housing and a right handle joint fixed to the right part of the gear housing. The holding member may be fixed to one of the left handle joint and the right handle joint, and the reaction force receiving member may be fixed to the other handle joint.

[0020] In the above configuration, an operator can receive the reaction force transmitted from the rotary output unit to the gear housing via the reaction force receiving member. Thereby, it is possible to suppress the posture of the electric excavator from becoming unstable or the operator holding the electric excavator from wobbling. Therefore, a target hole is formed in the excavation target. Further, since interference between the auxiliary pole and the reaction force receiving member is suppressed, the excavation work is smoothly performed.

[0021] In one or more embodiments, the handle joint may have a threaded hole. The holding member may have a plurality of threaded openings provided at intervals in the front-rear direction. The handle joint and the holding member may be fixed by inserting a screw into the threaded hole through the threaded opening. By selecting the threaded opening into which the screw is inserted, the position of the auxiliary pole in the front-rear direction may be adjusted.

[0022] In the above configuration, the position of the auxiliary pole in the front-rear direction is easily adjusted. The distance in the front-rear direction between the drill bit and the auxiliary pole is appropriately adjusted according to the situation at the work site.

[0023] In one or more embodiments, the auxiliary handle may include a handle joint fixed to the gear housing and a handle fixed to the handle joint. The holding member may be fixed to the handle.

[0024] In the above configuration, the holding member is fixed to the gear housing via the handle and the handle joint.

[0025] In one or more embodiments, the holding member may include a first holding member and a second holding member disposed below the first holding member. The first holding member and the second holding member may be arranged to sandwich the handle in the vertical direction.

[0026] In the above configuration, since the first holding member and the second holding member are arranged to sandwich the handle in the vertical direction, the fixing between the holding member and the handle is stabilized.

[0027] In one or more embodiments, one of the first holding member and the second holding member may have a screw opening. The other holding member of the first holding member and the second holding member may have a screw hole. By inserting a screw through the screw opening into the screw hole, the first holding member, the second holding member, and the handle may be fixed.

[0028] In the above configuration, the first holding member, the second holding member, and the handle are fixed by a screw.

[0029] In one or more embodiments, the handle may be arranged to extend forward from the handle joint. By releasing the fixing of the first holding member and the second holding member to the handle by a screw, the position of the auxiliary pole in the front-rear direction may be adjusted.

[0030] In the above configuration, the position of the auxiliary pole in the front-rear direction is easily adjusted. According to the situation at the work site, the distance in the front-rear direction between the drill bit and the auxiliary pole is properly adjusted.

[0031] In one or more embodiments, the handle joint may include a left handle joint fixed to the left part of the gear housing and a right handle joint fixed to the right part of the gear housing. The handle may include a left rod portion extending forward from the left handle joint, a right rod portion extending forward from the right handle joint, and a connecting rod portion connecting the front end portion of the left rod portion and the front end portion of the right rod portion. The holding member may be fixed to each of the left rod portion and the right rod portion. In the left-right direction, the auxiliary pole may be arranged outside one of the left handle joint and the right handle joint, and a reaction force receiving member may be fixed to the other handle joint.

[0032] In the above configuration, since the holding member is fixed to each of the left rod portion and the right rod portion, the fixing of the holding member and the handle is stabilized. An operator can receive the reaction force transmitted from the rotary output portion to the gear housing via the reaction force receiving member. Thereby, it is suppressed that the posture of the electric excavator becomes unstable or the operator holding the electric excavator sways. Therefore, a target hole is formed in the excavation target. Further, since the interference between the auxiliary pole and the reaction force receiving member is suppressed, the excavation work is smoothly performed.

[0033] In one or more embodiments, the attachment is mounted on an electric excavator. The electric excavator may include a motor housing that houses a motor, a handle housing that is disposed on the rear side of the motor housing and has a grip portion provided with a trigger switch for starting the motor, a gear housing that is disposed on the front side of the motor housing and houses gears, and a rotary output portion that protrudes downward from the gear housing and to which a drill bit is attached. The attachment may be disposed on at least one of the left side and the right side of the gear housing, and may include an auxiliary plate that receives a reaction force transmitted from the rotary output portion to the gear housing.

[0034] In the above configuration, the auxiliary plate can assist the excavation work so that a target hole is formed in the excavation target. An operator can receive the reaction force transmitted from the rotary output portion to the gear housing via the auxiliary plate. Thereby, it is suppressed that the posture of the electric excavator becomes unstable or the operator holding the electric excavator sways. Therefore, a target hole is formed in the excavation target.

[0035] In one or more embodiments, the front end portion of the auxiliary plate may be disposed in front of the front end portion of the gear housing.

[0036] In the above configuration, since the outer shape of the auxiliary plate is larger than the outer shape of the gear housing, an operator can receive the reaction force transmitted from the rotary output portion to the gear housing via the auxiliary plate.

[0037] In one or more embodiments, the attachment may include an auxiliary handle that is detachably attached to the gear housing. The auxiliary plate may be fixed to at least a part of the auxiliary handle. The auxiliary handle may include a handle joint including a left handle joint fixed to the left part of the gear housing and a right handle joint fixed to the right part of the gear housing, and a handle fixed to the handle joint. The auxiliary plate may be fixed to one of the left handle joint and the right handle joint.

[0038] In the above configuration, when the auxiliary handle is gripped by the operator's hand, the excavation work can be smoothly performed. The auxiliary handle can assist the excavation work so that a target hole is formed. Since the auxiliary plate is fixed to one of the left handle joint and the right handle joint, the operator can receive the reaction force transmitted from the rotary output portion to the gear housing through the auxiliary handle and the auxiliary plate.

[0039] In one or more embodiments, the electric drill may include a motor housing that houses a motor, a handle housing that is disposed on the rear side of the motor housing and has a grip portion provided with a trigger switch, a gear housing that is disposed on the front side of the motor housing and houses gears, a rotary output portion that protrudes downward from the gear housing and to which a drill bit is attached, and the above-described attachment.

[0040] In the above configuration, since the excavation work is assisted by the attachment, a target hole is formed in the excavation target.

[0041] In one or more embodiments, the electric drill may include a motor housing that houses a motor, a first grip portion disposed on the left side of the motor housing, a second grip portion disposed on the right side of the motor housing, a trigger switch for starting the motor, a gear housing connected to the motor housing and housing gears, a rotary output portion that protrudes downward from the gear housing and to which a drill bit is attached, and an auxiliary pole disposed along the vertical direction at a position adjacent to the drill bit.

[0042] In the above configuration, the auxiliary pole can assist the drilling operation so that a target hole is formed in the object to be drilled. A hole is formed in the object to be drilled as the drill bit rotates. The target hole is formed in the object to be drilled when the auxiliary pole contacts the surface of the object to be drilled around the hole formed by the drill bit.

[0043] In one or more embodiments, the lower end portion of the auxiliary pole may be disposed above the lower end portion of the drill bit.

[0044] In the above configuration, since the lower end portion of the auxiliary pole is disposed above the lower end portion of the drill bit, a hole having a target depth is formed in the object to be drilled. The vertical distance between the lower end portion of the auxiliary pole and the lower end portion of the cutting edge of the drill bit is defined as the target depth of the hole, and the drilling operation is performed until the lower end portion of the auxiliary pole contacts the surface of the object to be drilled around the hole formed by the drill bit, whereby a hole having a target depth is formed in the object to be drilled.

[0045] In one or more embodiments, the auxiliary pole may be disposed on the left side or the right side of the rotary output portion, be movable in the vertical direction, and be fixed at a defined position in the vertical direction.

[0046] In the above configuration, since the auxiliary pole is disposed on the left side or the right side of the rotary output portion, it is suppressed that the auxiliary pole obstructs the drilling operation. Also, since the vertical position of the auxiliary pole is adjustable, a hole having a target depth is formed in the object to be drilled.

[0047] In one or more embodiments, the auxiliary pole may be attached to at least one of the motor housing and the gear housing.

[0048] In the above configuration, since the auxiliary pole is attached to an appropriate part of the electric drill, it is possible to suppress the auxiliary pole from interfering with the drilling operation.

[0049] In one or more embodiments, the electric drill may include a motor housing that houses a motor, a first grip portion disposed on the left side of the motor housing, a second grip portion disposed on the right side of the motor housing, a trigger switch for starting the motor, a gear housing connected to the motor housing and housing gears, a rotary output portion protruding downward from the gear housing to which a drill bit is attached, and an auxiliary plate attached to at least one of the motor housing and the gear housing for receiving, with the body of an operator, the reaction force generated by the rotation of the rotary output portion.

[0050] In the above configuration, the auxiliary plate can assist the drilling operation so that a target hole is formed in the object to be drilled. The operator can receive, via the auxiliary plate, the reaction force transmitted from the rotary output portion to the gear housing. Thereby, it is possible to suppress the posture of the electric drill from becoming unstable or the operator holding the electric drill from wobbling. Therefore, a target hole is formed in the object to be drilled.

[0051] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. Also, some components may not be used.

[0052] In the embodiments, terms such as "left", "right", "front", "rear", "upper", and "lower" are used to describe the positional relationship of each part. These terms indicate a relative position or direction based on the center of the electric drill.

[0053] [First Embodiment] <Electric Excavator> FIG. 1 is a front perspective view showing the electric excavator 1A according to the present embodiment. FIG. 2 is a rear perspective view showing the electric excavator 1A according to the present embodiment. FIG. 3 is a side view showing the electric excavator 1A according to the present embodiment. FIG. 4 is a cross-sectional view showing the electric excavator 1A according to the present embodiment.

[0054] The electric excavator 1A is a portable electric excavator that excavates an excavation target while being held by an operator to form a hole in the excavation target. In the present embodiment, the excavation target is the ground.

[0055] The electric excavator 1A includes a motor housing 2, a handle housing 3, a gear housing 4, a front grip 6, a battery mounting portion 7, a controller 13, a main switch 10, a trigger switch 11, a forward / reverse switching lever 9, a speed switching lever 15, a motor 8, a speed reduction mechanism 14, and a rotational output portion 5.

[0056] The motor housing 2 houses the motor 8. The motor housing 2 is cylindrical. The motor housing 2 is made of synthetic resin. The motor housing 2 has an exhaust port 2E that connects the internal space and the external space of the motor housing 2. The exhaust port 2E is provided in each of the left, right, and lower portions of the motor housing 2. The air in the internal space of the motor housing 2 is discharged to the external space through the exhaust port 2E.

[0057] The handle housing 3 is disposed at the rear side of the motor housing 2. The front portion of the handle housing 3 is connected to the rear portion of the motor housing 2. The handle housing 3 is in the shape of a long loop in the front-rear direction. The handle housing 3 is made of synthetic resin. The handle housing 3 includes a front portion 3A connected to the rear portion of the motor housing 2, a grip portion 3B extending rearward from the upper portion of the front portion 3A, a controller housing portion 3C extending rearward from the lower portion of the front portion 3A, and a battery connection portion 3D connecting the rear end portion of the grip portion 3B and the rear end portion of the controller housing portion 3C. The grip portion 3B is disposed above the controller housing portion 3C. The grip portion 3B is disposed at the rear side of the motor housing 2. An operator can hold the grip portion 3B by hand.

[0058] The gear housing 4 houses the speed reduction mechanism 14. The gear housing 4 is cylindrical. The gear housing 4 is disposed at the front side of the motor housing 2. The rear portion of the gear housing 4 is connected to the front portion of the motor housing 2. The gear housing 4 is made of aluminum. At least a part of the surface of the gear housing 4 is covered with a cover 4A. In the embodiment, the cover 4A has a two-layer structure of synthetic resin and elastomer.

[0059] The front grip 6 is fixed to the gear housing 4. The front grip 6 includes a left arm portion 6L fixed to the left portion of the gear housing 4, a right arm portion 6R fixed to the right portion of the gear housing 4, and a bridge portion 6H connecting the upper end portion of the left arm portion 6L and the upper end portion of the right arm portion 6R. The bridge portion 6H is disposed above the upper surface of the gear housing 4. The bridge portion 6H and the gear housing 4 face each other with a gap therebetween. The front grip 6 is disposed at the front side of the motor housing 2. An operator can hold the front grip 6.

[0060] Threaded openings 6C are provided at the lower ends of the left arm portion 6L and the right arm portion 6R, respectively. Threaded holes 16 are provided in the left and right portions of the gear housing 4, respectively. In the front-rear direction, the positions of the threaded holes 16 and the position of the rotational output portion 5 are substantially equal.

[0061] Threaded holes 18 are provided in the left and right portions of the gear housing 4, respectively. The threaded holes 18 are provided behind and below the threaded holes 16.

[0062] The battery mounting portion 7 is disposed at the rear of the handle housing 3. A battery pack 17 is mounted on the battery mounting portion 7. The battery mounting portion 7 is provided at the battery connection portion 3D of the handle housing 3. In the present embodiment, two battery mounting portions 7 are provided in the vertical direction. By mounting a battery pack 17 on each of the two battery mounting portions 7, two battery packs 17 are arranged in the vertical direction. The battery pack 17 is detachable from the battery mounting portion 7. By being mounted on the battery mounting portion 7, the battery pack 17 can supply power to the electric excavator 1A.

[0063] The battery pack 17 includes a secondary battery. In the present embodiment, the battery pack 17 includes a rechargeable lithium-ion battery. The battery pack 17 has a release button 17C. The release button 17C is operated to release the fixation between the battery mounting portion 7 and the battery pack 17. The release button 17C is provided on the left surface of the battery pack 17.

[0064] The controller 13 outputs a control signal for controlling the electric excavator 1A. The controller housing portion 3C has an internal space capable of housing the controller 13. The controller 13 is housed in the controller housing portion 3C.

[0065] The main switch 10 is operated by an operator to start the electric excavator 1A. The main switch 10 is provided at the upper part of the front portion 3A. When the main switch 10 is operated, power is supplied from the battery pack 17 to the controller 13, and the electric excavator 1A starts up. When the main switch 10 is operated, the start and stop of the electric excavator 1A are switched.

[0066] The trigger switch 11 is operated by an operator to start the motor 8. The trigger switch 11 is provided at the grip portion 3B. The trigger switch 11 includes a trigger lever 11A and a switch circuit 11B. The trigger lever 11A protrudes downward from the lower part of the front portion of the grip portion 3B. The operator can operate the trigger lever 11A with a finger so that the trigger lever 11A moves upward while holding the grip portion 3B with one of the left and right hands. The grip portion 3B has an internal space capable of accommodating the switch circuit 11B. The switch circuit 11B is accommodated in the grip portion 3B. The switch circuit 11B outputs an operation signal when the trigger lever 11A is operated. In a state where the electric excavator 1A is started, when the trigger lever 11A is operated to be pulled upward, power is supplied from the battery pack 17 to the motor 8, and the motor 8 starts up. The motor 8 is driven based on the operation signal output from the switch circuit 11B. By switching the operation and cancellation of the operation of the trigger lever 11A, the drive and stop of the motor 8 are switched.

[0067] The forward / reverse switching lever 9 is operated by an operator to switch the rotation direction of the motor 8. The forward / reverse switching lever 9 is provided at the front portion 3A. When the forward / reverse switching lever 9 is operated in the left-right direction, the rotation direction of the motor 8 is switched between the forward rotation direction and the reverse rotation direction. When the rotation direction of the motor 8 is switched, the rotation direction of the rotation output portion 5 is switched between the forward rotation direction and the reverse rotation direction.

[0068] The speed change lever 15 is operated by an operator to switch the rotational speed of the rotary output unit 5. The speed change lever 15 is provided at the lower part of the gear housing 4. When the speed change lever 15 is operated in the front-rear direction, the rotational speed of the rotary output unit 5 is switched between a first speed and a second speed higher than the first speed.

[0069] The motor 8 generates a rotational force for rotating the rotary output unit 5. The motor 8 is driven based on the electric power supplied from the battery pack 17. The motor 8 is an inner rotor type brushless motor. The motor 8 has a cylindrical stator 81 and a rotor 82 disposed inside the stator 81. The rotation axis AX of the rotor 82 extends in the front-rear direction.

[0070] The stator 81 has a stator core 81A including a plurality of laminated steel plates, a front insulator 81B disposed at the front part of the stator core 81A, a rear insulator 81C disposed at the rear part of the stator core 81A, a plurality of coils 81D wound around the stator core 81A via the front insulator 81B and the rear insulator 81C, a sensor circuit board 81E attached to the rear insulator 81C, and a connection member 81F supported by the rear insulator 81C. The sensor circuit board 81E has a plurality of rotation detection elements for detecting the rotation of the rotor 82.

[0071] The rotor 82 has a rotor shaft 82A, a cylindrical rotor core 82B disposed around the rotor shaft 82A, and a plurality of permanent magnets 82C held by the rotor core 82B. The front part of the rotor shaft 82A is rotatably supported by a bearing 83. The rear part of the rotor shaft 82A is rotatably supported by a bearing 84.

[0072] A centrifugal fan 85 is attached to a rotor shaft 82A between a bearing 83 and a stator 81. An exhaust port 2E of the motor housing 2 is arranged in a part around the centrifugal fan 85. When the rotor shaft 82A rotates and the centrifugal fan 85 rotates, the air in the internal space of the motor housing 2 is discharged to the external space of the motor housing 2 through the exhaust port 2E.

[0073] A pinion gear 141S is provided at the front end of the rotor shaft 82A. The pinion gear 141S is arranged in the internal space of the gear housing 4. The rotor shaft 82A is connected to the speed reduction mechanism 14 via the pinion gear 141S.

[0074] The speed reduction mechanism 14 transmits the rotational force generated by the motor 8 to the rotational output part 5. The speed reduction mechanism 14 transmits the rotational force from the rotor shaft 82A to the rotational output part 5. The speed reduction mechanism 14 includes a plurality of gears. The speed reduction mechanism 14 has a first planetary gear mechanism 141, a second planetary gear mechanism 142, an intermediate shaft 143, and an output shaft 144.

[0075] The first planetary gear mechanism 141 is arranged in front of the rotor shaft 82A. The intermediate shaft 143 is arranged in front of the first planetary gear mechanism 141. The second planetary gear mechanism 142 is arranged in front of the intermediate shaft 143. The output shaft 144 is arranged in front of the second planetary gear mechanism 142.

[0076] The first planetary gear mechanism 141 has a pinion gear 141S that functions as a sun gear, a plurality of planetary gears 141P arranged around the pinion gear 141S, a first carrier 141C that rotatably supports the plurality of planetary gears 141P, an internal gear 141R arranged around the plurality of planetary gears 141P, and a support pin 145 held by the first carrier 141C.

[0077] The pinion gear 141S is provided at the front end of the rotor shaft 82A. A plurality of planetary gears 141P mesh with the pinion gear 141S and the internal gear 141R respectively. The first carrier 141C holds the support pins 145. The support pins 145 extend in the front-rear direction. The support pins 145 are connected to the planetary gears 141P. The first carrier 141C rotatably supports the planetary gears 141P via the support pins 145.

[0078] The second planetary gear mechanism 142 includes a sun gear 142S, a plurality of planetary gears 142P arranged around the sun gear 142S, a second carrier 142C rotatably supporting the plurality of planetary gears 142P, an internal gear 142R arranged around the plurality of planetary gears 142P, and a support pin 146 held by the second carrier 142C.

[0079] The sun gear 142S is provided at the front end of the intermediate shaft 143. A plurality of planetary gears 142P mesh with the sun gear 142S and the internal gear 142R respectively. The second carrier 142C holds the support pin 146. The support pin 146 extends in the front-rear direction. The support pin 146 protrudes rearward from the second carrier 142C. The support pin 146 rotatably supports the planetary gears 142P. The rear end portion of the support pin 146 protrudes rearward from the planetary gears 142P. The second carrier 142C rotatably supports the planetary gears 142P via the support pin 146.

[0080] The internal gear 141R of the first planetary gear mechanism 141 is fixed to the gear housing 4. The internal gear 141R does not rotate. The internal gear 142R of the second planetary gear mechanism 142 is rotatable.

[0081] The output shaft 144 is rotatably supported by a bearing 147. The rear end portion of the output shaft 144 is fixed to the second carrier 142C. A bevel gear 148 is provided at the front end portion of the output shaft 144. The front end portion of the output shaft 144 is connected to the rotary output portion 5 via the bevel gear 148. When the second carrier 142C rotates, the second carrier 142C and the output shaft 144 rotate together.

[0082] The rotation axis AX of the rotor shaft 82A, the rotation axis of the first carrier 141C, the rotation axis of the intermediate shaft 143, the rotation axis of the second carrier 142C, and the rotation axis of the output shaft 144 coincide.

[0083] The speed reduction mechanism 14 has a switching member 150 that is movable in the front-rear direction between the first planetary gear mechanism 141 and the second planetary gear mechanism 142. The switching member 150 is disposed around the intermediate shaft 143. The switching member 150 is connected to the speed switching lever 15. The switching member 150 moves in the front-rear direction when the speed switching lever 15 is operated. An operator can operate the speed switching lever 15 to move the switching member 150 in the front-rear direction.

[0084] The switching member 150 is disposed in front of the first carrier 141C. The front portion of the support pin 145 projects forward from the first carrier 141C. The switching member 150 has a hole 150H into which the support pin 145 that projects forward from the first carrier 141C is inserted. The switching member 150 is movable in the front-rear direction while being guided by the support pin 145. When the switching member 150 moves in the front-rear direction, the rotational speed of the rotary output portion 5 is switched.

[0085] Further, the speed reduction mechanism 14 has a connecting member 151 provided at the rear portion of the planetary gear 142P. The connecting member 151 has a hole 151H into which a support pin 146 that projects rearward from the planetary gear 142P is inserted. The connecting member 151 is connected to the second carrier 142C via the support pin 146.

[0086] The switching member 150 is movable between a first position and a second position that is forward of the first position. The switching member 150 is movable between the first position and the second position while being guided by the support pin 145.

[0087] In a state where the switching member 150 is disposed at the first position, the switching member 150 is connected to each of the first carrier 141C and the intermediate shaft 143. Also, in a state where the switching member 150 is disposed at the first position, the switching member 150 is separated from the connecting member 151. In a state where the switching member 150 is disposed at the first position, the first carrier 141C, the rear end portion of the intermediate shaft 143, and the switching member 150 are integrated. When the first carrier 141C rotates in a state where the switching member 150 is disposed at the first position, the first carrier 141C, the intermediate shaft 143, and the switching member 150 rotate together.

[0088] In a state where the switching member 150 is disposed at the second position, the switching member 150 is connected to the connecting member 151. Also, in a state where the switching member 150 is disposed at the second position, the switching member 150 is separated from each of the first carrier 141C and the intermediate shaft 143. In a state where the switching member 150 is disposed at the second position, the rear end portion of the intermediate shaft 143 and the first carrier 141C are separated. In a state where the switching member 150 is disposed at the second position, the connecting member 151 and the switching member 150 are integrated. The support pin 145 is disposed in the hole 150H of the switching member 150. Also, the support pin 145 is connected to the planetary gear 141P. When the planetary gear 141P revolves in a state where the switching member 150 is disposed at the second position, the connecting member 151 and the switching member 150 rotate together.

[0089] In a state where the switching member 150 is disposed at the first position, the switching member 150 and the intermediate shaft 143 are connected by a spline connection. In a state where the switching member 150 is disposed at the second position, the spline connection is released and the connection between the switching member 150 and the intermediate shaft 143 is released.

[0090] When the rotor shaft 82A rotates due to the drive of the motor 8 with the switching member 150 disposed at the first position, the pinion gear 141S rotates, and the planetary gear 141P revolves around the pinion gear 141S. In the state where the switching member 150 is disposed at the first position, the first carrier 141C, the rear end portion of the intermediate shaft 143, and the switching member 150 are integrated. Due to the revolution of the planetary gear 141P, the first carrier 141C, the intermediate shaft 143, and the switching member 150 rotate together at a rotational speed lower than the rotational speed of the rotor shaft 82A. Due to the rotation of the intermediate shaft 143, the sun gear 142S rotates. When the sun gear 142S rotates, the planetary gear 142P revolves around the sun gear 142S. Due to the revolution of the planetary gear 142P, the second carrier 142C and the output shaft 144 rotate at a rotational speed lower than the rotational speed of the intermediate shaft 143. Thus, when the motor 8 is driven with the switching member 150 disposed at the first position, both the speed reduction function of the first planetary gear mechanism 141 and the speed reduction function of the second planetary gear mechanism 142 are exerted, and the output shaft 144 rotates at the first speed.

[0091] With the switching member 150 disposed at the second position, when the rotor shaft 82A rotates by driving the motor 8, the pinion gear 141S rotates, and the planetary gear 141P revolves around the pinion gear 141S. Due to the revolution of the planetary gear 141P, the first carrier 141C rotates together at a rotational speed lower than the rotational speed of the rotor shaft 82A. In a state where the switching member 150 is disposed at the second position, the switching member 150 is separated from the first carrier 141C and the intermediate shaft 143. In a state where the switching member 150 is disposed at the second position, the rear end portion of the intermediate shaft 143 and the first carrier 141C are separated. In a state where the switching member 150 is disposed at the second position, the connecting member 151 and the switching member 150 are integral. In a state where the switching member 150 is disposed at the second position, the support pin 145 is disposed in the hole 150H of the switching member 150. Due to the revolution of the planetary gear 141P, the connecting member 151 and the switching member 150 rotate at the same rotational speed as the rotational speed of the first carrier 141C. Due to the rotation of the connecting member 151, the planetary gear 142P revolves at the same revolution speed as the rotational speed of the connecting member 151. Due to the revolution of the planetary gear 142P, the second carrier 142C and the output shaft 144 rotate at the same rotational speed as the rotational speed of the intermediate shaft 143. Thus, in a state where the switching member 150 is disposed at the second position, when the motor 8 is driven, although the deceleration function of the first planetary gear mechanism 141 is exerted, the deceleration function of the second planetary gear mechanism 142 is not exerted, and the output shaft 144 rotates at the second speed.

[0092] The rotation output unit 5 rotates based on the rotational force transmitted from the motor 8 via the speed reduction mechanism 14. The rotation output unit 5 protrudes downward from the front portion of the gear housing 4. A drill bit is attached to the rotation output unit 5. The rotation output unit 5 is rotatable with the drill bit attached thereto. The rotation axis BX of the rotation output unit 5 extends in the vertical direction. The rotation axis AX of the motor 8 and the rotation axis BX of the rotation output unit 5 are orthogonal to each other.

[0093] The rotary output unit 5 includes a spindle 51 and a drill chuck 52 attached to the lower end of the spindle 51. The drill chuck 52 has an insertion hole 52A into which a drill bit is inserted. The insertion hole 52A is formed to extend upward from the lower end of the drill chuck 52. The drill chuck 52 is rotatable with a drill bit attached thereto.

[0094] The spindle 51 is rotatably supported by each of a needle bearing 53 and a ball bearing 54. The needle bearing 53 rotatably supports the upper end of the spindle 51. The ball bearing 54 rotatably supports the lower part of the spindle 51.

[0095] A bevel gear 55 is provided at the upper end of the spindle 51. The bevel gear 55 meshes with a bevel gear 148 of the output shaft 144. The diameter of the bevel gear 55 is larger than the diameter of the bevel gear 148. The number of teeth of the bevel gear 55 is more than the number of teeth of the bevel gear 148.

[0096] <Operation> Next, an example of the operation of the electric excavator 1A according to the present embodiment will be described. When the main switch 10 is operated with the battery pack 17 mounted on the battery mounting portion 7, power is supplied from the battery pack 17 to the electric excavator 1A. When the trigger switch 11 is operated while power is being supplied from the battery pack 17 to the electric excavator 1A, an operation signal is output from the switch circuit 11B. The controller 13 supplies current to the motor 8 based on the operation signal output from the switch circuit 11B. When current is supplied to the motor 8, the rotor shaft 82A rotates.

[0097] Due to the rotation of the rotor shaft 82A, each of the first planetary gear mechanism 141, the intermediate shaft 143, and the second planetary gear mechanism 142 is driven, and the output shaft 144 rotates. The bevel gear 148 of the output shaft 144 meshes with the bevel gear 55 of the spindle 51. Due to the rotation of the output shaft 144, the spindle 51 rotates. Due to the rotation of the spindle 51, the drill chuck 52 rotates. Due to the rotation of the drill chuck 52, the drill bit attached to the drill chuck 52 rotates.

[0098] Due to the rotation of the rotor shaft 82A, the centrifugal fan 85 rotates. Due to the rotation of the centrifugal fan 85, air circulates around the motor 8. By the circulation of air around the motor 8, the motor 8 is cooled. The air that has circulated around the motor 8 is discharged from the exhaust port 2E.

[0099] <Attachment> FIG. 5 is an exploded perspective view from the front showing a part of the attachment 100 according to the present embodiment. FIG. 6 is an exploded perspective view from the rear showing a part of the attachment 100 according to the present embodiment. FIG. 7 is a perspective view from the front showing a part of the attachment 100 according to the present embodiment. FIG. 8 is a perspective view from the rear showing a part of the attachment 100 according to the present embodiment.

[0100] The attachment 100 is attached to the electric excavator 1A. In the present embodiment, the attachment 100 is attached to the gear housing 4 of the electric excavator 1A. The attachment 100 is detachable from the gear housing 4 of the electric excavator 1A.

[0101] The attachment 100 includes an auxiliary handle 20 that is detachable from the gear housing 4. The auxiliary handle 20 receives the reaction force transmitted from the rotation output unit 5 to the gear housing 4. The auxiliary handle 20 has a handle joint 21, a handle 22, and a reaction force receiving member 23.

[0102] The handle joint 21 is fixed to the gear housing 4. The handle joint 21 includes a left handle joint 21L fixed to the left part of the gear housing 4 and a right handle joint 21R fixed to the right part of the gear housing 4.

[0103] The handle 22 is fixed to the handle joint 21. The handle 22 is arranged to extend forward from the handle joint 21. The handle 22 includes a left rod part 22L extending forward from the left handle joint 21L, a right rod part 22R extending forward from the right handle joint 21R, and a connecting rod part 22C connecting the front end part of the left rod part 22L and the front end part of the right rod part 22R.

[0104] The handle 22 is manufactured by bending a single pipe. Note that the handle 22 may be manufactured by welding a plurality of pipes. The handle 22 is made of a metal such as aluminum. In the present embodiment, each of the front end part of the left rod part 22L, the front end part of the right rod part 22R, and the connecting rod part 22C is covered with a cover 22E. The cover 22E is made of a synthetic resin or rubber.

[0105] The reaction force receiving member 23 is fixed to the handle joint 21. The reaction force receiving member 23 is arranged outside (left side) of the handle joint 21 with respect to the center of the auxiliary handle 20 in the left - right direction. The reaction force receiving member 23 includes a fixed rod part 23A extending in the front - rear direction and an overhanging rod part 23B protruding outside (left side) of the center of the auxiliary handle 20 in the left - right direction from the front end part of the fixed rod part 23A.

[0106] The reaction force receiving member 23 is manufactured by bending a single pipe. Note that the reaction force receiving member 23 may be manufactured by welding a plurality of pipes. The reaction force receiving member 23 is made of a metal such as aluminum. In the present embodiment, at least a part of the fixed rod portion 23A is covered with a cover 23C. The cover 23C is made of a synthetic resin or rubber. At least a part of the protruding rod portion 23B is covered with a cover 23D. The cover 23D is made of a synthetic resin or rubber.

[0107] The handle joint 21 has a main body portion 21A, a screw boss portion 21B, and a screw boss portion 21C.

[0108] The main body portion 21A has an inner surface facing the center side of the auxiliary handle 20 in the left - right direction and an outer surface facing the opposite side of the inner surface. The inner surface of the main body portion 21A faces the gear housing 4.

[0109] The screw boss portion 21B is provided so as to protrude outward from the outer surface of the main body portion 21A in the left - right direction with respect to the center of the auxiliary handle 20.

[0110] The screw boss portion 21C is connected to the rear and lower portions of the main body portion 21A.

[0111] The main body portion 21A has a handle hole 24, an inner concave portion 25, an outer concave portion 26, a screw hole 27, and a screw opening 28. The screw boss portion 21B has a screw opening 29. The screw boss portion 21C has a screw opening 30.

[0112] The handle hole 24 is formed to extend rearward from the front end portion of the main body portion 21A. The rear end portion of the left rod portion 22L is inserted into the handle hole 24 of the left handle joint 21L. The rear end portion of the right rod portion 22R is inserted into the handle hole 24 of the right handle joint 21R.

[0113] The inner concave portion 25 is provided so as to notch a part of the upper surface of the main body portion 21A and a part of the inner surface of the main body portion 21A. At least a part of the front grip 6 is disposed in the inner concave portion 25. The left arm portion 6L is disposed in the inner concave portion 25 of the left handle joint 21L. The right arm portion 6R is disposed in the inner concave portion 25 of the right handle joint 21R.

[0114] The outer concave portion 26 is provided on the outer surface of the main body portion 21A. The outer concave portion 26 is provided so as to be recessed from the outer surface of the main body portion 21A toward the center of the auxiliary handle 20 in the left-right direction. The outer concave portion 26 is provided so as to extend in the front-rear direction. A part of the fixed rod portion 23A is disposed in the outer concave portion 26.

[0115] When a virtual axis extending in the front-rear direction is defined as the front-rear axis, in a plane orthogonal to the front-rear axis, the inner surface of the outer concave portion 26 is in an arc shape that is recessed toward the left-right center of the auxiliary handle 20. In a plane orthogonal to the front-rear axis, the outer surface of the fixed rod portion 23A facing the inner surface of the outer concave portion 26 is in an arc shape that bulges toward the left-right center of the auxiliary handle 20. The inner surface of the outer concave portion 26 and the outer surface of the fixed rod portion 23A are in contact with each other.

[0116] The screw holes 27 are provided in the outer concave portion 26. Two screw holes 27 are provided in the outer concave portion 26 at intervals in the front-rear direction. Screw openings 23E are provided in the fixed rod portion 23A and the cover 23C. Five screw openings 23E are provided at intervals in the front-rear direction. With the fixed rod portion 23A disposed in the outer concave portion 26, the screws 31 are inserted into the screw holes 27 through the screw openings 23E. Thereby, the handle joint 21 and the reaction force receiving member 23 are fixed by the screws 31.

[0117] Two screws 31 are arranged in the front-rear direction. By selecting the screw openings 23E into which the screws 31 are inserted, the position of the reaction force receiving member 23 in the front-rear direction is adjusted.

[0118] The reaction force receiving member 23 is fixed to one of the left handle joint 21L and the right handle joint 21R of the handle joints 21. When fixing the left handle joint 21L and the reaction force receiving member 23, with the fixed rod portion 23A disposed in the outer concave portion 26 of the left handle joint 21L, the fixed rod portion 23A and the left handle joint 21L are fixed by a screw 31. When fixing the right handle joint 21R and the reaction force receiving member 23, with the fixed rod portion 23A disposed in the outer concave portion 26 of the right handle joint 21R, the fixed rod portion 23A and the right handle joint 21R are fixed by a screw 31.

[0119] Figures 5 and 6 show a state where the handle joint 21 and the reaction force receiving member 23 are separated. Figures 7 and 8 show a state where the left handle joint 21L and the reaction force receiving member 23 are fixed by a screw 31.

[0120] Two screw openings 29 are provided at intervals in the front-rear direction in the screw boss portion 21B. The screw openings 29 are formed so as to communicate with the inner surface of the handle hole 24. Screws 32 for fixing the handle joint 21 and the handle 22 are inserted into the screw openings 29. Two screws 32 are arranged in the front-rear direction. The screws 32 inserted into the screw openings 29 are inserted into screw holes provided in at least a part of the handle 22. The handle joint 21 and the handle 22 are fixed by the screws 32. The screws 32 inserted into the screw openings 29 of the left handle joint 21L are inserted into the screw holes provided in the left rod portion 22L, thereby fixing the left handle joint 21L and the left rod portion 22L. The screws 32 inserted into the screw openings 29 of the right handle joint 21R are inserted into the screw holes provided in the right rod portion 22R, thereby fixing the right handle joint 21R and the right rod portion 22R.

[0121] FIG. 9 is a front perspective view showing the electric excavator 1A with a part of the attachment 100 according to the present embodiment mounted thereon. FIG. 10 is a rear perspective view showing the electric excavator 1A with a part of the attachment 100 according to the present embodiment mounted thereon. FIG. 11 is a front perspective view showing the electric excavator 1A with a part of the attachment 100 according to the present embodiment mounted thereon. FIG. 12 is a rear perspective view showing the electric excavator 1A with a part of the attachment 100 according to the present embodiment mounted thereon. Each of FIGS. 9 and 10 shows a state in which the auxiliary handle 20 in a state where the handle 22 is fixed to the handle joint 21 and the reaction force receiving member 23 is not fixed is mounted on the electric excavator 1A. Each of FIGS. 11 and 12 shows a state in which the auxiliary handle 20 in a state where the handle 22 and the reaction force receiving member 23 are each fixed to the handle joint 21 is mounted on the electric excavator 1A.

[0122] The screw opening 28 is provided on the front side of the screw boss portion 21B in the main body portion 21A. A screw 33 for fixing the handle joint 21 and the gear housing 4 via the front grip 6 is inserted into the screw opening 28. The screw 33 inserted into the screw opening 28 is inserted into the screw hole 16 of the gear housing 4 through the screw opening 6C of the front grip 6 described with reference to FIGS. 1 to 3. The handle joint 21 and the gear housing 4 are fixed by the screw 33 via the front grip 6. The screw 33 inserted into the screw opening 28 of the left handle joint 21L is inserted into the screw hole 16 of the left portion of the gear housing 4 through the screw opening 6C of the left arm portion 6L, thereby fixing the left handle joint 21L and the left portion of the gear housing 4. The screw 33 inserted into the screw opening 28 of the right handle joint 21R is inserted into the screw hole 16 of the right portion of the gear housing 4 through the screw opening 6C of the right arm portion 6R, thereby fixing the right handle joint 21R and the right portion of the gear housing 4.

[0123] The screw opening 30 is provided in the screw boss portion 21C. A screw 34 for fixing the handle joint 21 and the gear housing 4 is inserted into the screw opening 30. The screw 34 inserted into the screw opening 30 is inserted into the screw hole 18 of the gear housing 4 described with reference to FIG. 3 and the like. The handle joint 21 and the gear housing 4 are fixed by the screw 34. The screw 34 inserted into the screw opening 30 of the left handle joint 21L is inserted into the screw hole 18 in the left portion of the gear housing 4, thereby fixing the left handle joint 21L and the left portion of the gear housing 4. The screw 34 inserted into the screw opening 30 of the right handle joint 21R is inserted into the screw hole 18 in the right portion of the gear housing 4, thereby fixing the right handle joint 21R and the right portion of the gear housing 4.

[0124] <Auxiliary pole> FIG. 13 is a front perspective view showing the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto. FIG. 14 is a rear perspective view showing the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto. FIG. 15 is a view of the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto as seen from the left side. FIG. 16 is a view of the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto as seen from the right side. FIG. 17 is a view of the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto as seen from the upper side. FIG. 18 is a view of the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto as seen from the lower side. FIG. 19 is a view of the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto as seen from the rear side. FIG. 20 is a view of the electric excavator 1A with the attachment 100 according to the present embodiment attached thereto as seen from the front side.

[0125] As shown in FIGS. 13 to 20, a drill bit 19 is attached to the rotational output portion 5. The drill bit 19 is a drill bit for ground excavation called an earth auger drill bit. The drill bit 19 has a drilling shaft 19A, a drilling blade 19B, a tip bit 19C, and a cutting bit 19D.

[0126] The excavation shaft 19A is arranged along the vertical direction. When attaching the drill bit 19 to the rotary output unit 5, as shown in FIGS. 9 to 12, the adapter 5A is inserted into the insertion hole 52A of the drill chuck 52. The adapter 5A is a rod-shaped member. A hole is provided at the upper end of the excavation shaft 19A into which the adapter 5A is inserted. With the adapter 5A inserted into the hole at the upper end of the excavation shaft 19A, the upper end of the excavation shaft 19A and the adapter 5A are fixed by the fixture 5B. The upper end of the excavation shaft 19A is attached to the drill chuck 52 via the adapter 5A.

[0127] The excavation blade 19B is arranged spirally around the excavation shaft 19A. The excavation blade 19B is fixed to the excavation shaft 19A.

[0128] The tip bit 19C is arranged at the lower end of the excavation shaft 19A.

[0129] The cutting bit 19D is arranged at the lower end of the excavation blade 19B.

[0130] As shown in FIGS. 11 and 12, the attachment 100 includes an auxiliary handle 20 that is detachably attached to the gear housing 4. The auxiliary handle 20 has a left handle joint 21L, a right handle joint 21R, a handle 22, and a reaction force receiving member 23.

[0131] As shown in FIGS. 13 to 20, the attachment 100 further includes an auxiliary pole 40. The auxiliary pole 40 is arranged along the vertical direction at a position adjacent to the drill bit 19.

[0132] FIG. 21 is an exploded perspective view showing the auxiliary pole 40 according to the present embodiment. As shown in FIGS. 13 to 21, the auxiliary pole 40 has a pipe portion 40A, a leg portion 40B, and a cap portion 40C.

[0133] The pipe part 40A is made of a straight metal pipe. The pipe part 40A is arranged along the vertical direction. The pipe part 40A is arranged parallel to the excavation shaft 19A. The pipe part 40A is provided with screw openings 40D. Two screw openings 40D are provided at intervals in the vertical direction.

[0134] The leg part 40B is attached to the lower end part of the pipe part 40A. The leg part 40B is arranged so as to close the opening at the lower end part of the pipe part 40A. The leg part 40B is made of rubber. As shown in FIG. 21, the leg part 40B has a plug part 40E inserted into the opening at the lower end part of the pipe part 40A and a flange part 40F connected to the lower end part of the plug part 40E. The outer diameter of the flange part 40F is larger than the outer diameter of the pipe part 40A.

[0135] The cap part 40C is attached to the upper end part of the pipe part 40A. The cap part 40C is arranged so as to close the opening at the upper end part of the pipe part 40A. At least a part of the cap part 40C is inserted into the opening at the upper end part of the pipe part 40A. The cap part 40C is made of rubber.

[0136] The lower end part 40U of the auxiliary pole 40 is arranged above the lower end part 19U of the drill bit 19. When the drill bit 19 rotates, a hole is formed in the ground. The lower end part 40U of the auxiliary pole 40 contacts the ground around the hole formed by the drill bit 19, thereby assisting the excavation work by the electric excavator 1A so that the depth of the hole becomes the target depth.

[0137] The attachment 100 further includes a holding member 41 that is detachably attached to at least a part of the auxiliary handle 20. The auxiliary pole 40 is held by the holding member 41. The holding member 41 is fixed to the handle joint 21. The auxiliary pole 40 is supported by the handle joint 21 via the holding member 41.

[0138] The holding member 41 is fixed to one of the left handle joint 21L and the right handle joint 21R, i.e., the handle joint 21. In the example shown in FIGS. 13 to 20, the reaction force receiving member 23 is fixed to the left handle joint 21L. The holding member 41 is fixed to the right handle joint 21R. The auxiliary pole 40 is supported by the right handle joint 21R via the holding member 41.

[0139] The holding member 41 extends in the front-rear direction. A part of the holding member 41 is disposed in the outer concave portion 26 of the right handle joint 21R.

[0140] As described above, in the plane orthogonal to the front-rear axis, the inner surface of the outer concave portion 26 is an arc-shaped recess toward the center of the auxiliary handle 20 in the left-right direction. In the plane orthogonal to the front-rear axis, the outer surface of the holding member 41 facing the inner surface of the outer concave portion 26 is an arc-shaped bulge toward the center of the auxiliary handle 20 in the left-right direction. The inner surface of the outer concave portion 26 and the outer surface of the holding member 41 are in contact.

[0141] As described above, the right handle joint 21R has a screw hole 27 provided in the outer concave portion 26. Two screw holes 27 are provided in the outer concave portion 26 at intervals in the front-rear direction. The holding member 41 has a plurality of screw openings 42 provided at intervals in the front-rear direction. Six screw openings 42 are provided at intervals in the front-rear direction. With the holding member 41 disposed in the outer concave portion 26, the screw 35 is inserted into the screw hole 27 through the screw opening 42. Thereby, the right handle joint 21R and the holding member 41 are fixed by the screw 35.

[0142] Two screws 35 are arranged in the front-rear direction. By selecting the screw opening 42 into which the screw 35 is inserted, the position of the holding member 41 and the auxiliary pole 40 held by the holding member 41 in the front-rear direction is adjusted.

[0143] FIG. 22 is a perspective view showing the auxiliary pole 40 and the holding member 41 according to the present embodiment. The holding member 41 has a holding mechanism 43 for detachably holding the auxiliary pole 40.

[0144] The holding mechanism 43 has a clamp portion 44 disposed at least partially around the auxiliary pole 40 and a lever 46 connected to the clamp portion 44 via a hinge 45.

[0145] The clamp portion 44 can fix the auxiliary pole 40. The clamp portion 44 is provided at the front end portion of the holding member 41. The clamp portion 44 has an arc portion 44A, a plate portion 44B, and a plate portion 44C. In the present embodiment, the clamp portion 44 is a part of the holding member 41. The arc portion 44A is disposed at least partially around the pipe portion 40A. The plate portion 44B is provided at one end of the arc portion 44A. The plate portion 44C is provided at the other end of the arc portion 44A. The plate portion 44B and the plate portion 44C face each other with a gap therebetween. The plate portion 44B and the plate portion 44C are connected by a screw 47.

[0146] The lever 46 is connected to the clamp portion 44 via the hinge 45. The lever 46 is rotatably supported by the clamp portion 44 via the hinge 45. The lever 46 is operated by an operator so that the auxiliary pole 40 is fixed by the clamp portion 44. The lever 46 has a cam portion that contacts the plate portion 44B of the clamp portion 44. When the lever 46 is rotated in the fastening direction Ya indicated by the arrow in FIG. 22, the pipe portion 40A of the auxiliary pole 40 is clamped by the clamp portion 44, and the auxiliary pole 40 is fixed to the clamp portion 44. That is, the auxiliary pole 40 is fixed to the front end portion of the holding member 41. When the lever 46 is rotated in the relaxation direction Yb indicated by the arrow in FIG. 22, the fixing of the auxiliary pole 40 by the clamp portion 44 is released. When the fixing of the auxiliary pole 40 is released, the operator can move the auxiliary pole 40 in the vertical direction with respect to the clamp portion 44. The operator can adjust the vertical position of the auxiliary pole 40 with respect to the holding member 41.

[0147] <Usage method> Next, a method of using the electric excavator 1A according to the present embodiment will be described. FIG. 23 is a side view for explaining a method of using the electric excavator 1A to which the attachment 100 according to the present embodiment is attached. FIG. 24 is a plan view for explaining a method of using the electric excavator 1A to which the attachment 100 according to the present embodiment is attached. As shown in FIGS. 23 and 24, when excavating the ground with the electric excavator 1A, a drill bit 19 is attached to the rotary output unit 5, and the attachment 100 is attached to the gear housing 4.

[0148] The operator holds the connecting rod portion 22C of the handle 22 with the left hand and holds the grip portion 3B of the handle housing 3 with the right hand. Further, the operator brings the protruding rod portion 23B of the reaction force receiving member 23 into contact with the left part of the body. The operator brings the protruding rod portion 23B into contact with at least one of the left side abdomen, the left waist, and the thigh portion of the left leg.

[0149] The operator operates the trigger lever 11A with the fingers of the right hand that holds the grip portion 3B. When the trigger lever 11A is operated, the rotary output unit 5 rotates in the specified direction Ra indicated by the arrow in FIG. 24 with the drill bit 19 attached.

[0150] The operator presses the auxiliary handle 20 and the electric excavator 1A downward to press the rotating drill bit 19 against the ground. When the rotating drill bit 19 is pressed against the ground, the ground is excavated and a hole is formed in the ground. The operator can press the handle 22 downward with the left hand and press the grip portion 3B downward with the right hand. Further, the operator can press the front grip 6 downward with the abdomen. When the front grip 6 is pressed downward, the gear housing 4 is pressed downward.

[0151] In ground excavation, a large reaction force Vr may act on the gear housing 4 in the upward direction indicated by the arrow in FIG. 23 via the drill bit 19 and the rotary output section 5. Also, a large reaction force Hr may act on the gear housing 4 in the direction opposite to the specified direction Ra indicated by the arrow in FIG. 24 via the drill bit 19 and the rotary output section 5.

[0152] Further, in ground excavation, when the drill bit 19 hits a hard foreign object such as a rock, an excessive reaction force may suddenly act on the gear housing 4. When a large reaction force acts on the gear housing 4, the posture of the electric excavator 1A may become unstable, or the operator holding the electric excavator 1A may stagger. As a result, it may become difficult to form a target hole in the ground.

[0153] In the present embodiment, an auxiliary handle 20 for receiving the reaction force transmitted from the rotary output section 5 to the gear housing 4 is attached to the electric excavator 1A. The auxiliary handle 20 includes a handle 22 and a reaction force receiving member 23 for receiving the reaction force transmitted from the rotary output section 5 to the gear housing 4.

[0154] By being gripped with the left hand of the operator, the connecting rod portion 22C can receive the vertical reaction force Vr parallel to the rotation axis BX of the rotary output section 5 and the reaction force Hr in the rotation direction of the rotary output section 5.

[0155] By being gripped with the right hand of the operator, the grip portion 3B can receive the vertical reaction force Vr parallel to the rotation axis BX of the rotary output section 5 and the reaction force Hr in the rotation direction of the rotary output section 5.

[0156] By contacting the body of the operator, the protruding rod portion 23B can receive the reaction force Hr in the rotation direction of the rotary output section 5.

[0157] The connecting rod part 22C is arranged in front of the gear housing 4. The grip part 3B is arranged behind the gear housing 4. The protruding rod part 23B is arranged on the side of the gear housing 4. The connecting rod part 22C held by the operator's left hand is away from the rotational output part 5. The grip part 3B held by the operator's right hand is away from the rotational output part 5. The protruding rod part 23B contacting the operator's body is away from the rotational output part 5.

[0158] As shown in FIG. 23, the upward reaction force Vr transmitted to the gear housing 4 is dispersed to each of the connecting rod part 22C, the grip part 3B, and the front grip 6. Since the reaction force Vr transmitted to the gear housing 4 is dispersed to each of the connecting rod part 22C, the grip part 3B, and the front grip 6, the dispersed reaction force Vr is transmitted to the operator. Therefore, even if a large reaction force Vr acts on the gear housing 4, it is suppressed that the posture of the electric excavator 1A becomes unstable or the operator holding the electric excavator 1A sways.

[0159] Also, as shown in FIG. 24, the reaction force Hr in the rotational direction transmitted to the gear housing 4 is dispersed to each of the connecting rod part 22C, the grip part 3B, and the protruding rod part 23B. Since the reaction force Hr transmitted to the gear housing 4 is dispersed to each of the connecting rod part 22C, the grip part 3B, and the protruding rod part 23B, the dispersed reaction force Hr is transmitted to the operator. Therefore, even if a large reaction force Hr acts on the gear housing 4, it is suppressed that the posture of the electric excavator 1A becomes unstable or the operator gripping the electric excavator 1A sways.

[0160] In the present embodiment, the attachment 100 includes an auxiliary pole 40 disposed along the vertical direction at a position adjacent to the drill bit 19. The lower end portion 40U of the auxiliary pole 40 is disposed above the lower end portion 19U of the drill bit 19. The vertical distance ΔD between the lower end portion of the cutting edge 19B and the lower end portion 19U of the drill bit 19 is determined as the target depth of the hole formed in the ground. The operator performs the excavation work by the electric excavator 1A until the lower end portion 40U of the auxiliary pole 40 contacts the ground around the hole formed by the drill bit 19. By performing the excavation work by the electric excavator 1A until the lower end portion 40U of the auxiliary pole 40 contacts the ground around the hole formed by the drill bit 19, a hole with the target depth is formed in the ground.

[0161] When the excavation work is completed, the operator can grasp at least one of the handle 22, the reaction receiving member 23, the grip portion 3B, and the front grip 6 by hand and pull the electric excavator 1A upward. When the electric excavator 1A is pulled upward, the drill bit 19 comes out of the hole formed in the ground.

[0162] <Effect> As described above, in the present embodiment, the attachment 100 is attached to the electric excavator 1A. The electric excavator 1A includes a motor housing 2 that houses the motor 8, a handle housing 3 that is disposed on the rear side of the motor housing 2 and has a grip portion 3B provided with a trigger switch 11 for starting the motor 8, a gear housing 4 that is disposed on the front side of the motor housing 2 and houses gears, and a rotary output portion 5 that protrudes downward from the gear housing 4 and to which the drill bit 19 is attached. The attachment 100 includes an auxiliary pole 40 disposed along the vertical direction at a position adjacent to the drill bit 19.

[0163] In the above configuration, the auxiliary pole 40 can assist the drilling operation so that the target hole is formed in the ground to be drilled. When the drill bit 19 rotates, a hole is formed in the ground. By the auxiliary pole 40 contacting the ground around the hole formed by the drill bit 19, the target hole is formed in the ground.

[0164] In the present embodiment, the lower end portion 40U of the auxiliary pole 40 is disposed above the lower end portion 19U of the drill bit 19.

[0165] In the above configuration, since the lower end portion 40U of the auxiliary pole 40 is disposed above the lower end portion 19U of the drill bit 19, a hole with the target depth is formed in the ground. The vertical distance ΔD between the lower end of the cutting edge 19B and the lower end portion 19U of the drill bit 19 is defined as the target depth of the hole, and the drilling operation is performed until the lower end portion 40U of the auxiliary pole 40 contacts the ground around the hole formed by the drill bit 19, whereby a hole with the target depth is formed in the ground.

[0166] In the present embodiment, the attachment 100 includes an auxiliary handle 20 that is detachably attached to the gear housing 4, and a holding member 41 that is detachably attached to at least a part of the auxiliary handle 20. The auxiliary pole 40 is held by the holding member 41.

[0167] In the above configuration, when the auxiliary handle 20 is grasped by the operator's hand, the drilling operation is smoothly performed. Since the auxiliary pole 40 is supported by the auxiliary handle 20 via the holding member 41, the operator can form a hole with the target depth in the ground while grasping the auxiliary handle 20 with the hand.

[0168] In the present embodiment, the holding member 41 has a holding mechanism 43 for detachably holding the auxiliary pole 40. The holding mechanism 43 includes a clamp portion 44 disposed at at least a part around the auxiliary pole 40, and a lever 46 connected to the clamp portion 44 via a hinge 45. When the lever 46 is rotated in the fastening direction Ya, the auxiliary pole 40 is fixed to the clamp portion 44. When the lever 46 is rotated in the relaxation direction Yb, the fixing of the auxiliary pole 40 by the clamp portion 44 is released.

[0169] In the above configuration, when the lever 46 is rotated in the fastening direction Ya, the vertical position of the auxiliary pole 40 with respect to the holding member 41 is fixed. When the lever 46 is rotated in the relaxation direction Yb, the vertical position of the auxiliary pole 40 with respect to the holding member 41 is adjusted.

[0170] In the present embodiment, the auxiliary handle 20 includes a handle joint 21 fixed to the gear housing 4, and a handle 22 fixed to the handle joint 21. The holding member 41 is fixed to the handle joint 21.

[0171] In the above configuration, the holding member 41 is fixed to the gear housing 4 via the handle joint 21. An operator can grip the handle 22 by hand.

[0172] In the present embodiment, the handle joint 21 includes a left handle joint 21L fixed to the left part of the gear housing 4, and a right handle joint 21R fixed to the right part of the gear housing 4. The holding member 41 is fixed to the right handle joint 21R, and the reaction force receiving member 23 is fixed to the left handle joint 21L.

[0173] In the above configuration, the operator can receive the reaction force transmitted from the rotary output unit 5 to the gear housing 4 via the reaction force receiving member 23. Thereby, it is possible to suppress the posture of the electric excavator 1A from becoming unstable or the operator holding the electric excavator 1A from wobbling. Therefore, the target hole is formed on the ground. Further, since the interference between the auxiliary pole 40 and the reaction force receiving member 23 is suppressed, the excavation work is smoothly performed.

[0174] In addition, in the present embodiment, the reaction force receiving member 23 may be fixed to the right handle joint 21R, and the holding member 41 may be fixed to the left handle joint 21L.

[0175] In the present embodiment, the handle joint 21 has a threaded hole 27. The holding member 41 has a plurality of screw openings 42 provided at intervals in the front-rear direction. By inserting the screw 35 into the threaded hole 27 through the screw opening 42, the handle joint 21 and the holding member 41 are fixed. By selecting the screw opening 42 into which the screw 35 is inserted, the position of the auxiliary pole 40 in the front-rear direction is adjusted.

[0176] In the above configuration, the position of the auxiliary pole 40 in the front-rear direction is easily adjusted. The distance in the front-rear direction between the drill bit 19 and the auxiliary pole 40 is appropriately adjusted according to the situation at the work site.

[0177] In addition, in the present embodiment, the handle 22 disposed on the left hand side (front side) of the motor housing 2 may be regarded as the first grip portion held by the left hand of the operator, and the grip portion 3B disposed on the right hand side (rear side) of the motor housing 2 may be regarded as the second grip portion.

[0178] In the above configuration, the operator can smoothly perform the excavation work while holding the first grip portion disposed on the front side of the rotary output unit 5 and the second grip portion disposed on the rear side of the rotary output unit 5.

[0179] In addition, in the present embodiment, the auxiliary pole 40 is attached to the gear housing 4 via the holding member 41. The auxiliary pole 40 may be attached to the motor housing 2 or may be attached to the handle housing 3. By attaching the auxiliary pole 40 to an appropriate part of the electric excavator 1A, it is possible to prevent the auxiliary pole 40 from interfering with the excavation work.

[0180] [Second Embodiment] The second embodiment will be described. In the following description, the same reference numerals are given to the same or equivalent components as those in the above-described embodiment, and the description of those components will be simplified or omitted.

[0181] FIG. 25 is a front perspective view showing the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto. FIG. 26 is a rear perspective view showing the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto. FIG. 27 is a view of the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto as seen from the left side. FIG. 28 is a view of the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto as seen from the right side. FIG. 29 is a view of the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto as seen from the upper side. FIG. 30 is a view of the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto as seen from the lower side. FIG. 31 is a view of the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto as seen from the rear side. FIG. 32 is a view of the electric excavator 1A with the attachment 101 according to the present embodiment attached thereto as seen from the front side.

[0182] Similar to the above-described embodiment, the attachment 101 includes an auxiliary handle 20. The auxiliary handle 20 includes a handle joint 21 including a left handle joint 21L and a right handle joint 21R, a handle 22, and a reaction force receiving member 23.

[0183] Similar to the above-described embodiment, the attachment 101 includes an auxiliary pole 40. The auxiliary pole 40 is arranged along the vertical direction at a position adjacent to the drill bit 19. The reaction force receiving member 23 is fixed to the left handle joint 21L. In the present embodiment, the holding member 41 is not fixed to the right handle joint 21R.

[0184] The attachment 101 includes a holding member 60 that is detachably attached to at least a part of the auxiliary handle 20. The auxiliary pole 40 is held by the holding member 60. In the present embodiment, the holding member 60 is fixed to the handle 22. The holding member 60 extends in the left-right direction. The auxiliary pole 40 is supported by the handle 22 via the holding member 60.

[0185] FIG. 33 is a perspective view showing the auxiliary pole 40 and the holding member 60 according to the present embodiment. FIG. 34 is a cross-sectional view showing the auxiliary pole 40 and the holding member 60 according to the present embodiment, corresponding to the cross-sectional view taken along the line A-A in FIG. 33 and viewed in the arrow direction.

[0186] The holding member 60 includes a first holding member 61 and a second holding member 62 disposed below the first holding member 61. The first holding member 61 is a plate-like member that is long in the left-right direction. The second holding member 62 is a plate-like member that is long in the left-right direction. The first holding member 61 has an upper surface 61A and a lower surface 61B. The second holding member 62 has an upper surface 62A and a lower surface 62B. The lower surface 61B of the first holding member 61 and the upper surface 62A of the second holding member 62 face each other. The first holding member 61 and the second holding member 62 are arranged so as to sandwich the handle 22 in the vertical direction.

[0187] The holding member 60 is fixed to each of the left rod portion 22L and the right rod portion 22R. The first holding member 61 and the second holding member 62 are arranged so as to sandwich each of the left rod portion 22L and the right rod portion 22R in the vertical direction.

[0188] A recess 61L and a recess 61R are provided on the lower surface 61B of the first holding member 61. Each of the recess 61L and the recess 61R is provided so as to be recessed upward from the lower surface 61B. The recess 61L and the recess 61R are provided at intervals in the left - right direction. The recess 61R is provided on the right side of the recess 61L. A part of the left rod portion 22L is disposed in the recess 61L. A part of the right rod portion 22R is disposed in the recess 61R.

[0189] A recess 62L and a recess 62R are provided on the upper surface 62A of the second holding member 62. Each of the recess 62L and the recess 62R is provided so as to be recessed downward from the upper surface 62A. The recess 62L and the recess 62R are provided at intervals in the left - right direction. The recess 62R is provided on the right side of the recess 62L. A part of the left rod portion 22L is disposed in the recess 62L. A part of the right rod portion 22R is disposed in the recess 62R.

[0190] When a virtual axis extending in the front - rear direction is taken as the front - rear axis, in a plane orthogonal to the front - rear axis, each of the inner surface of the recess 61L and the inner surface of the recess 61R is in an arc shape that is recessed upward from the lower surface 61B. In a plane orthogonal to the front - rear axis, each of the outer surface of the left rod portion 22L facing the inner surface of the recess 61L and the outer surface of the right rod portion 22R facing the inner surface of the recess 61R is in an arc shape that bulges upward. The inner surface of the recess 61L and the outer surface of the left rod portion 22L are in contact. The inner surface of the recess 61R and the outer surface of the right rod portion 22R are in contact.

[0191] When a virtual axis extending in the front - rear direction is taken as the front - rear axis, in a plane orthogonal to the front - rear axis, each of the inner surface of the recess 62L and the inner surface of the recess 62R is in an arc shape that is recessed downward from the upper surface 62A. In a plane orthogonal to the front - rear axis, each of the outer surface of the left rod portion 22L facing the inner surface of the recess 62L and the outer surface of the right rod portion 22R facing the inner surface of the recess 62R is in an arc shape that bulges downward. The inner surface of the recess 62L and the outer surface of the left rod portion 22L are in contact. The inner surface of the recess 62R and the outer surface of the right rod portion 22R are in contact.

[0192] The first holding member 61 has a screw opening 63. The second holding member 62 has a screw hole 64. When a screw 65 is inserted into the screw hole 64 through the screw opening 63, the handle 22 is clamped between the first holding member 61 and the second holding member 62, and the first holding member 61 and the second holding member 62 are fixed to the handle 22.

[0193] The first holding member 61 has a holding hole 61H in which the pipe portion 40A of the auxiliary pole 40 is disposed. The second holding member 62 has a holding hole 62H in which the pipe portion 40A of the auxiliary pole 40 is disposed. The holding hole 61H is provided on the right side of the recess 61R. The holding hole 62H is provided on the right side of the recess 62R.

[0194] In the present embodiment, five screw openings 63 and five screw holes 64 are provided at intervals in the left - right direction. Five screws 65 are provided in the left - right direction. The screws 65 include a screw 65A, a screw 65B, a screw 65C, a screw 65D, and a screw 65E. In the left - right direction, the screw 65A and the screw 65B are disposed on both sides of the left rod portion 22L. In the left - right direction, the screw 65C and the screw 65D are disposed on both sides of the right rod portion 22R. In the left - right direction, the screw 65D and the screw 65E are disposed on both sides of the pipe portion 40A.

[0195] When the fixing of the handle 22 by the screw 65 between the first holding member 61 and the second holding member 62 is released, the position of the holding member 60 and the auxiliary pole 40 held by the holding member 60 in the front - rear direction is adjusted.

[0196] The holding member 60 has a holding mechanism 73 for detachably holding the auxiliary pole 40.

[0197] The holding mechanism 73 has a clamp portion 74 disposed at at least a part around the auxiliary pole 40, and a lever 76 connected to the clamp portion 74 via a hinge 75.

[0198] The clamping portion 74 can fix the auxiliary pole 40. The clamping portion 74 is provided at the lower part of the right end portion of the second holding member 62. The clamping portion 74 has an arc portion 74A, a plate portion 74B, and a plate portion 74C. In the present embodiment, the clamping portion 74 is a part of the second holding member 62. The arc portion 74A is arranged around a part of the pipe portion 40A. The plate portion 74B is provided at one end portion of the arc portion 74A. The plate portion 74C is provided at the other end portion of the arc portion 74A. The plate portion 74B and the plate portion 74C face each other with a gap therebetween. The plate portion 74B and the plate portion 74C are connected by a screw 77.

[0199] The lever 76 is connected to the clamping portion 74 via a hinge 75. The lever 76 is rotatably supported by the clamping portion 74 via the hinge 75. The lever 76 is operated by an operator so that the auxiliary pole 40 is fixed by the clamping portion 74. The lever 76 has a cam portion that contacts the plate portion 74C of the clamping portion 74. When the lever 76 is rotated in the fastening direction Yc indicated by the arrow in FIG. 33, the pipe portion 40A of the auxiliary pole 40 is clamped by the clamping portion 74, and the auxiliary pole 40 is fixed to the clamping portion 74. That is, the auxiliary pole 40 is fixed to the right end portion of the second holding member 62. When the lever 76 is rotated in the relaxation direction Yd indicated by the arrow in FIG. 33, the fixing of the auxiliary pole 40 is released. When the fixing of the auxiliary pole 40 is released, the operator can move the auxiliary pole 40 in the vertical direction with respect to the clamping portion 74. The operator can adjust the vertical position of the auxiliary pole 40 with respect to the holding member 60.

[0200] In the present embodiment, in the left - right direction, the auxiliary pole 40 is arranged outside (right side) of the right - handle joint 21R with respect to the center of the auxiliary handle 20, and the reaction - force receiving member 23 is fixed to the left - handle joint 21L.

[0201] FIG. 35 is a front perspective view showing the attachment 101 and the electric excavator 1A according to the present embodiment. FIG. 36 is a view of the attachment 101 and the electric excavator 1A according to the present embodiment as seen from the right side.

[0202] As described above, in the present embodiment, the holding member 41 is not fixed to the right handle joint 21R. In the present embodiment, when the auxiliary pole 40 is not used, the auxiliary pole 40 is fixed to the right handle joint 21R.

[0203] As shown in FIGS. 35 and 36, the pipe portion 40A of the auxiliary pole 40 is disposed in the outer recess 26 of the right handle joint 21R. The pipe portion 40A disposed in the outer recess 26 of the right handle joint 21R is sandwiched between the right handle joint 21R and the cover 66. The cover 66 is provided with screw openings 67. Two screw openings 67 are provided at intervals in the front-rear direction. As described above, screw holes 27 are provided in the outer recess 26, and screw openings 40D are provided in the pipe portion 40A. Screws 36 inserted into the screw openings 67 of the cover 66 and the screw openings 40D of the pipe portion 40A are inserted into the screw holes 27. Thereby, the pipe portion 40A is fixed to the right handle joint 21R by the screws 36 while being sandwiched between the cover 66 and the right handle joint 21R.

[0204] As described above, in the present embodiment, the auxiliary handle 20 includes a handle joint 21 fixed to the gear housing 4 and a handle 22 fixed to the handle joint 21. The holding member 60 is fixed to the handle 22.

[0205] In the above configuration, the holding member 60 is fixed to the gear housing 4 via the handle 22 and the handle joint 21.

[0206] In the present embodiment, the holding member 60 includes a first holding member 61 and a second holding member 62 disposed below the first holding member 61. The first holding member 61 and the second holding member 62 are arranged to sandwich the handle 22 in the vertical direction.

[0207] In the above configuration, since the first holding member 61 and the second holding member 62 are arranged to sandwich the handle 22 in the vertical direction, the fixing between the holding member 60 and the handle 22 is stabilized.

[0208] In this embodiment, the first holding member 61 has a screw opening 63. The second holding member 62 has a screw hole 64. By inserting a screw 65 into the screw hole 64 through the screw opening 63, the first holding member 61, the second holding member 62, and the handle 22 are fixed.

[0209] In the above configuration, the first holding member 61, the second holding member 62, and the handle 22 are fixed by the screw 65.

[0210] Note that in this embodiment, the second holding member 62 may have a screw opening 63 and the first holding member 61 may have a screw hole 64.

[0211] In this embodiment, the handle 22 is arranged to extend forward from the handle joint 21. By releasing the fixing of the first holding member 61 and the second holding member 62 to the handle 22 by the screw 65, the position of the auxiliary pole 40 in the front-rear direction is adjusted.

[0212] In the above configuration, the position of the auxiliary pole 40 in the front-rear direction is easily adjusted. The distance in the front-rear direction between the drill bit 19 and the auxiliary pole 40 is appropriately adjusted according to the situation at the work site.

[0213] In this embodiment, the handle joint 21 includes a left handle joint 21L fixed to the left part of the gear housing 4 and a right handle joint 21R fixed to the right part of the gear housing 4. The handle 22 includes a left rod portion 22L extending forward from the left handle joint 21L, a right rod portion 22R extending forward from the right handle joint 21R, and a connecting rod portion 22C connecting the front end of the left rod portion 22L and the front end of the right rod portion 22R. The holding member 60 is fixed to each of the left rod portion 22L and the right rod portion 22R. In the left-right direction, the auxiliary pole 40 is arranged outside (right side) of the right handle joint 21R, and the reaction force receiving member 23 is fixed to the left handle joint 21L.

[0214] In the above configuration, since the holding member 60 is fixed to each of the left rod portion 22L and the right rod portion 22R, the fixing between the holding member 60 and the handle 22 is stabilized. An operator can receive the reaction force transmitted from the rotational output portion 5 to the gear housing 4 via the reaction force receiving member 23. Thereby, it is suppressed that the posture of the electric excavator 1A becomes unstable or the operator holding the electric excavator 1A sways. Therefore, a target hole is formed in the ground. Further, since the interference between the auxiliary pole 40 and the reaction force receiving member 23 is suppressed, the excavation work is smoothly performed.

[0215] In the present embodiment, in the left - right direction, the auxiliary pole 40 may be disposed outside (left side) the left handle joint 21L and the reaction force receiving member 23 may be fixed to the right handle joint 21R.

[0216] FIG. 37 is a perspective view from the front showing a modified example of the auxiliary pole 40 and the holding member 60 according to the present embodiment. In the example shown in FIGS. 25 to 34, in the left - right direction, the auxiliary pole 40 is disposed outside the handle 22 with respect to the center of the auxiliary handle 20. As shown in FIG. 37, the auxiliary pole 40 may be disposed between the left rod portion 22L and the right rod portion 22R in the left - right direction.

[0217] [Third Embodiment] The third embodiment will be described. In the following description, the same reference numerals are given to the same or equivalent components as those in the above - described embodiment, and the description of those components is simplified or omitted.

[0218] FIG. 38 is a front perspective view showing the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon. FIG. 39 is a rear perspective view showing the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon. FIG. 40 is a view of the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon as seen from the left side. FIG. 41 is a view of the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon as seen from the right side. FIG. 42 is a view of the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon as seen from the upper side. FIG. 43 is a view of the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon as seen from the lower side. FIG. 44 is a view of the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon as seen from the rear side. FIG. 45 is a view of the electric excavator 1A with the attachment 102 according to this embodiment mounted thereon as seen from the front side.

[0219] The attachment 102 includes an auxiliary handle 20. In this embodiment, as described with reference to FIGS. 9 and 10, the auxiliary handle 20 has a handle joint 21 including a left handle joint 21L and a right handle joint 21R, and a handle 22, and does not have a reaction force receiving member 23.

[0220] Similar to the above-described embodiment, the attachment 101 includes an auxiliary pole 40. The auxiliary pole 40 is arranged along the vertical direction at a position adjacent to the drill bit 19. The reaction force receiving member 23 is fixed to the left handle joint 21L. In this embodiment, the holding member 41 is not fixed to the right handle joint 21R.

[0221] The attachment 102 is arranged on the left side of the gear housing 4, and includes an auxiliary plate 90 that receives the reaction force transmitted from the rotational output portion 5 to the gear housing 4. The auxiliary plate 90 is fixed to at least a part of the auxiliary handle 20.

[0222] In this embodiment, the auxiliary plate 90 is fixed to the left handle joint 21L. The auxiliary plate 90 has screw openings 91. Two screw openings 91 are provided at intervals in the front-rear direction. As described above, the left handle joint 21L has a screw hole 27 formed in the outer concave portion 26. By inserting a screw 37 inserted into the screw opening 91 into the screw hole 27, the auxiliary plate 90 is fixed to the left handle joint 21L by the screw 37.

[0223] The auxiliary plate 90 has an opening 92 in which the screw boss portion 21B is disposed, a slit opening 93 provided in front of the opening 92, and an opening 94 provided behind the opening 92.

[0224] By disposing the screw boss portion 21B in the opening 92, the auxiliary plate 90 and the left handle joint 21L are positioned. In this embodiment, the screw boss portion 21B and the opening 92 function as a positioning mechanism for positioning the auxiliary plate 90 and the left handle joint 21L.

[0225] Two slit openings 93 are arranged in the vertical direction. For example, a binding band coupled to the left rod portion 22L is inserted into the slit opening 93. The left rod portion 22L and the front portion of the auxiliary plate 90 are fixed by the binding band.

[0226] The opening 94 is aligned with the screw 33.

[0227] With the auxiliary plate 90 fixed to the left handle joint 21L, the front end portion 90A of the auxiliary plate 90 is disposed in front of the front end portion of the gear housing 4. Further, the front end portion 90A of the auxiliary plate 90 is disposed behind the front end portion of the connecting rod portion 22C (cover 22E) which is the front end portion of the handle 22. The upper end portion of the auxiliary plate 90 is disposed above the upper end portion of the handle 22 and the upper end portion of the left handle joint 21L. The lower end portion of the auxiliary plate 90 is disposed below the lower end portion of the handle 22.

[0228] FIG. 46 is a side view for explaining a method of using the electric excavator 1A according to the present embodiment. FIG. 47 is a front view for explaining a method of using the electric excavator 1A according to the present embodiment. In the present embodiment, the excavation target of the electric excavator 1A is an earth wall. The electric excavator 1A to which the attachment 102 is attached is used to form a hole in the earth wall in the lateral direction. When forming a hole, the electric excavator 1A is positioned so that the connecting rod portion 22C (cover 22E), which is the front end portion of the handle 22, contacts the ground.

[0229] The operator holds the front grip 6 with the left hand and holds the grip portion 3B of the handle housing 3 with the right hand. Also, the operator brings the auxiliary plate 90 into contact with the right leg. The operator performs the excavation work in a crouched state so that at least a part of the inner side of the thigh, the inner side of the knee, and the inner side of the lower leg of the right leg contact the auxiliary plate 90.

[0230] The operator operates the trigger lever 11A with the fingers of the right hand holding the grip portion 3B. When the trigger lever 11A is operated, the rotary output portion 5 rotates in the specified direction Ra indicated by the arrow in FIG. 47 with the drill bit 19 attached.

[0231] The operator pushes the electric excavator 1A forward and presses the rotating drill bit 19 against the earth wall. When the rotating drill bit 19 is pressed against the earth wall, the earth wall is excavated and a hole is formed in the earth wall.

[0232] In the excavation of the earth wall, a large reaction force Gr may act on the gear housing 4 through the drill bit 19 and the rotary output portion 5 in a direction opposite to the specified direction Ra indicated by the arrow in FIG. 47.

[0233] In addition, when excavating an earthen wall, if the drill bit 19 hits a hard foreign object such as a rock, an excessive reaction force may suddenly act on the gear housing 4. When a large reaction force acts on the gear housing 4, the posture of the electric excavator 1A may become unstable, or the operator holding the electric excavator 1A may wobble. As a result, it may be difficult to form a target hole in the earthen wall.

[0234] In the present embodiment, an auxiliary plate 90 for receiving the reaction force transmitted from the rotary output portion 5 to the gear housing 4 is attached to the electric excavator 1A via the auxiliary handle 20.

[0235] The auxiliary plate 90 can receive the reaction force Gr in the rotational direction of the rotary output portion 5 by being pressed by the right foot of the operator. Therefore, even if a large reaction force Gr acts on the gear housing 4, the posture of the electric excavator 1A becoming unstable or the operator holding the electric excavator 1A wobbling is suppressed.

[0236] When the excavation work is completed, the operator can move the electric excavator 1A forward by gripping at least one of the handle 22, the grip portion 3B, and the front grip 6 with the hand. When the electric excavator 1A is moved forward, the drill bit 19 comes out of the hole formed in the earthen wall.

[0237] As described above, in the present embodiment, the attachment 102 is disposed on the left side of the gear housing 4 and includes an auxiliary plate 90 that receives the reaction force transmitted from the rotary output portion 5 to the gear housing 4.

[0238] In the above configuration, the auxiliary plate 90 can assist the excavation work so that the target hole is formed in the earthen wall that is the excavation target. The operator can receive the reaction force Gr transmitted from the rotary output portion 5 to the gear housing 4 via the auxiliary plate 90. Thereby, the posture of the electric excavator 1A becoming unstable or the operator holding the electric excavator 1A wobbling is suppressed. Therefore, the target hole is formed in the earthen wall.

[0239] In this embodiment, the front end portion 90A of the auxiliary plate 90 is disposed in front of the front end portion of the gear housing 4.

[0240] In the above configuration, since the outer shape of the auxiliary plate 90 is larger than the outer shape of the gear housing 4, an operator can receive the reaction force Gr transmitted from the rotary output portion 5 to the gear housing 4 via the auxiliary plate 90.

[0241] In this embodiment, the attachment 102 includes an auxiliary handle 20 that is attached to and detached from the gear housing 4. The auxiliary plate 90 is fixed to at least a part of the auxiliary handle 20. The auxiliary handle 20 includes a handle joint 21 including a left handle joint 21L fixed to the left part of the gear housing 4 and a right handle joint 21R fixed to the right part of the gear housing 4, and a handle 22 fixed to the handle joint 21. The auxiliary plate 90 is fixed to the left handle joint 21L.

[0242] In the above configuration, when the auxiliary handle 20 is gripped by the hand of an operator, the excavation work is smoothly performed. The auxiliary handle 20 can assist the excavation work so that a target hole is formed in the soil wall. Since the auxiliary plate 90 is fixed to the left handle joint 21L, an operator can receive the reaction force Gr transmitted from the rotary output portion 5 to the gear housing 4 via the auxiliary handle 20 and the auxiliary plate 90.

[0243] Note that, in this embodiment, the auxiliary plate 90 may be fixed to the right handle joint 21R, or may be fixed to both the left handle joint 21L and the right handle joint 21R.

[0244] Note that, in this embodiment, the handle 22 disposed on the left hand side (front side) of the motor housing 2 may be regarded as a first grip portion gripped by the left hand of an operator, and the grip portion 3B disposed on the right hand side (rear side) of the motor housing 2 may be regarded as a second grip portion.

[0245] In addition, in this embodiment, the auxiliary plate 90 is attached to the gear housing 4 via the auxiliary handle 20. The auxiliary plate 90 may be attached to the motor housing 2 or the handle housing 3. By attaching the auxiliary plate 90 to an appropriate part of the electric excavator 1A, the operator can receive a reaction force via the auxiliary plate 90.

[0246] [Fourth Embodiment] The fourth embodiment will be described. In the following description, components that are the same as or equivalent to those of the above-described embodiments are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0247] FIG. 48 is a perspective view from the front showing the electric excavator 1B according to this embodiment. The electric excavator 1B includes a motor housing 202, a first grip portion 203L, a second grip portion 203R, a trigger switch 211, a gear housing 204, a rotary output portion 205, and an auxiliary pole 240.

[0248] The motor housing 202 houses a motor. The motor housing 202 also houses a battery 217.

[0249] The first grip portion 203L is disposed on the left side of the motor housing 202. The second grip portion 203R is disposed on the right side of the motor housing 202. The trigger switch 211 is operated to start the motor. The trigger switch 211 is disposed on the second grip portion 203R.

[0250] The gear housing 204 is connected to the lower part of the motor housing 202. The gear housing 204 houses gears.

[0251] The rotary output portion 205 projects downward from the gear housing 204. A drill bit 219 is attached to the rotary output portion 205.

[0252] The auxiliary pole 240 is arranged along the vertical direction at a position adjacent to the drill bit 219. The auxiliary pole 240 has the same function as the auxiliary pole 40 described in the above-described first and second embodiments. The auxiliary pole 240 is arranged on the left side or the right side of the rotary output unit 205, is movable in the vertical direction, and is fixed at a specified position in the vertical direction. The auxiliary pole 240 is attached to at least one of the motor housing 202 and the gear housing 204. Note that the auxiliary pole 240 may be held by a holding member attached to at least one of the motor housing 202 and the gear housing 204.

[0253] [Fifth Embodiment] The fifth embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description of those components is simplified or omitted.

[0254] FIG. 49 is a perspective view from the front showing the electric excavator 1B according to the present embodiment. Similar to the above-described fourth embodiment, the electric excavator 1B includes a motor housing 202, a first grip portion 203L, a second grip portion 203R, a trigger switch 211, a gear housing 204, and a rotary output unit 205.

[0255] In the present embodiment, the electric excavator 1B includes an auxiliary plate 290. The auxiliary plate 290 has the same function as the auxiliary plate 90 described in the above-described third embodiment. The auxiliary plate 290 is attached to at least one of the motor housing 202 and the gear housing 204. The auxiliary plate 290 receives the reaction force generated by the rotation of the rotary output unit 205 with the body of the operator.

Description of Reference Numerals

[0256] 1A... Electric Excavator, 1B... Electric Excavator, 2... Motor Housing, 2E... Exhaust Port, 3... Handle Housing, 3A... Front Part, 3B... Grip Part, 3C... Controller Accommodation Part, 3D... Battery Connecting Part, 4... Gear Housing, 4A... Cover, 5... Rotational Output Part, 5A... Adapter, 5B... Fixture, 6... Front Grip, 6C... Screw Opening, 6H... Bridge Part, 6L... Left Arm Part, 6R... Right Arm Part, 7... Battery Mounting Part, 8... Motor, 9... Forward / Reverse Switch Lever, 10... Main Switch, 11... Trigger Switch, 11A... Trigger Lever, 11B... Switch Circuit, 13... Controller, 14... Reduction Mechanism, 15... Speed Switch Lever, 16... Screw Hole, 17... Battery Pack, 17C... Release Button, 18... Screw Hole, 19... Drill Bit, 19A... Excavation Shaft, 19B... Excavation Blade, 19C... Tip Bit, 19D... Cutting Bit, 19U... Lower End Part, 20... Auxiliary Handle, 21... Handle Joint, 21A... Main Body Part, 21B... Screw Boss Part, 21C... Screw Boss Part, 21L... Left Handle Joint, 21R... Right Handle Joint, 22... Handle, 22L... Left Rod Part, 22R... Right Rod Part, 22C... Connecting Rod Part, 22E... Cover, 23... Reaction Receiving Member, 23A... Fixed Rod Part, 23B... Projecting Rod Part, 23C... Cover, 23D... Cover, 23E... Screw Opening, 24... Handle Hole, 25... Inner Concave Part, 26... Outer Concave Part, 27... Screw Hole, 28... Screw Opening, 29... Screw Opening, 30... Screw Opening, 31... Screw, 32... Screw, 33... Screw, 34... Screw, 35... Screw, 36... Screw, 37... Screw, 40... Auxiliary Pole, 40A... Pipe Part, 40B... Leg Part, 40C... Cap Part, 40D... Screw Opening, 40E... Plug Part, 40F... Flange Part, 40U... Lower End Part, 41... Holding Member, 42... Screw Opening, 43... Holding Mechanism, 44... Clamp Part, 44A... Arc Part, 44B... Plate Part, 44C... Plate Part, 45... Hinge, 46... Lever, 47... Screw, 51... Spindle, 52... Drill Chuck, 52A... Insertion Hole, 53... Needle Bearing, 54... Ball Bearing, 55... Bevel Gear, 60... Holding Member, 61... First Holding Member, 61A... Upper Surface, 61B... Lower Surface, 61H... Holding Hole, 61L... Concave Part, 61R... Concave Part, 62... Second Holding Member, 62A... Upper Surface, 62B... Lower Surface, 62H... Holding Hole, 62L... Concave Part, 62R... Concave Part, 63... Screw Opening, 64... Screw Hole, 65... Screw, 65A... Screw, 65B... Screw,65C... screw, 65D... screw, 65E... screw, 66... cover, 67... screw opening, 73... holding mechanism, 74... clamp part, 74A... arc part, 74B... plate part, 74C... plate part, 75... hinge, 76... lever, 77... screw, 81... stator, 81A... stator core, 81B... front insulator, 81C... rear insulator, 81D... coil, 81E... sensor circuit board, 81F... connection member, 82... rotor, 82A... rotor shaft, 82B... rotor core, 82C... permanent magnet, 83... bearing, 84... bearing, 85... centrifugal fan, 90... auxiliary plate, 90A... front end part, 91... screw opening, 92... opening, 93... slit opening, 94... opening, 100... attachment, 101... attachment, 102... attachment, 141... first planetary gear mechanism, 141C... first carrier, 141P... planetary gear, 141R... internal gear, 141S... pinion gear, 142... second planetary gear mechanism, 142C... second carrier, 142P... planetary gear, 142R... internal gear, 142S... sun gear, 143... intermediate shaft, 144... output shaft, 145... support pin, 146... support pin, 147... bearing, 148... bevel gear, 150... switching member, 150H... hole, 151... connection member, 151H... hole, 202... motor housing, 203L... first grip part, 203R... second grip part, 204... gear housing, 205... rotational output part, 211... trigger switch, 217... battery, 219... drill bit, 240... auxiliary pole, 290... auxiliary plate, AX... rotation axis, BX... rotation axis, Gr... reaction force, Hr... reaction force, Ra... specified direction, Vr... reaction force, Ya... fastening direction, Yb... loosening direction, Yc... fastening direction, Yd... loosening direction, ΔD... distance.,

Claims

1. A motor housing for accommodating a motor, A handle housing having a grip portion disposed on the rear side of the motor housing and provided with a trigger switch for starting the motor, A gear housing disposed on the front side of the motor housing for accommodating gears, An attachment for being mounted on an electric excavator, comprising: a rotary output portion that protrudes downward from the gear housing and to which a drill bit that rotates about a rotary shaft extending in the vertical direction is attached, An auxiliary handle fixed to the gear housing and having a handle disposed on the front side of the gear housing, An auxiliary pole fixed to the gear housing and disposed along the vertical direction at a position adjacent to the drill bit, In the front-rear direction, the rotary output portion is disposed between the auxiliary handle and the handle housing, The handle is gripped by the left hand of the operator, and the grip portion is gripped by the right hand of the operator, The auxiliary pole is disposed to the right of the handle, Attachment.

2. The lower end portion of the auxiliary pole is disposed above the lower end portion of the drill bit, The attachment according to claim 1.

3. A motor housing for accommodating a motor, A handle housing having a grip portion disposed on the rear side of the motor housing and provided with a trigger switch for starting the motor, A gear housing disposed on the front side of the motor housing for accommodating gears, An attachment for being mounted on an electric excavator, comprising: a rotary output portion that protrudes downward from the gear housing and to which a drill bit is attached, An auxiliary pole disposed along the vertical direction at a position adjacent to the drill bit, An auxiliary handle detachable from the gear housing, A holding member detachable from at least a part of the auxiliary handle, The auxiliary pole is held by the holding member, Attachment.

4. The auxiliary handle has a handle joint fixed to the gear housing and a handle fixed to the handle joint, The holding member is fixed to the handle, The attachment according to claim 3.

5. A motor housing for accommodating a motor, A handle housing having a grip portion that is disposed on the rear side of the motor housing and is provided with a trigger switch; A gear housing that is disposed on the front side of the motor housing and houses gears; A rotary output portion that protrudes downward from the gear housing and to which a drill bit is attached; An attachment according to any one of claims 1 to 4; and An electric excavator.

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