Electric drilling machine, drilling system, and drill assembly

Abstract

To form a hole in an excavation target with good workability.SOLUTION: An electric drilling machine comprises a motor, a motor housing that accommodates the motor, a reduction mechanism, a gear housing that is arranged below the motor housing and accommodates the reduction mechanism, a rotational output section that protrudes forward from the gear housing and rotates based on the rotational force transmitted from the motor via the reduction mechanism with a drill bit attached, a first contact member that is arranged to the left of the gear housing and contacts the first support surface, and a second contact member that is arranged to the right of the gear housing and contacts the second support surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed herein relates to electric drilling machines, drilling systems, and drill assemblies. [Background technology]

[0002] 2. Description of the Related Art In the technical field related to electric excavators, there is known an electric tool that excavates the ground by rotating an earth auger drill bit, as disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-196098 A Summary of the Invention [Problem to be solved by the invention]

[0004] There are cases where it is necessary to form a hole using an electric drilling machine. For example, there are cases where it is necessary to form a horizontal hole using an electric drilling machine. For example, in plumbing work for installing a sewer pipe underground, there is a demand for a technique that allows the horizontal hole to be formed with good workability.

[0005] The technique disclosed in this specification aims to form a hole in an excavation target with good workability, and in particular to form a lateral hole in an excavation target with good workability. [Means for solving the problem]

[0006] This specification discloses an electric excavator. The electric excavator may include a motor, a motor housing that accommodates the motor, a reduction mechanism, a gear housing that is arranged below the motor housing and accommodates the reduction mechanism, a rotation output unit that protrudes forward from the gear housing and rotates based on a rotational force transmitted from the motor via the reduction mechanism with a drill bit attached, a first contact member that is arranged to the left of the gear housing and in contact with a first support surface, and a second contact member that is arranged to the right of the gear housing and in contact with a second support surface. Effect of the Invention

[0007] According to the technique disclosed in this specification, a hole can be formed in an excavation target with good workability. In particular, a lateral hole can be formed in an excavation target with good workability. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a front perspective view showing an excavation system according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view showing the excavation system according to the first embodiment, as viewed from the front. [Diagram 3] FIG. 3 is a rear perspective view showing the excavation system according to the first embodiment. [Figure 4] FIG. 4 is an exploded perspective view showing the excavation system according to the first embodiment, as viewed from the rear. [Diagram 5] FIG. 5 is a cross-sectional view showing the excavation system according to the first embodiment. [Figure 6] FIG. 6 is a side view showing the electric excavator according to the first embodiment. [Figure 7] FIG. 7 is a top view showing the electric excavator according to the first embodiment. [Figure 8] FIG. 8 is a bottom view showing the electric excavator according to the first embodiment. [Figure 9] FIG. 9 is a front view showing the electric excavator according to the first embodiment. [Figure 10] FIG. 10 is a rear view showing the electric excavator according to the first embodiment. [Figure 11] FIG. 11 is an exploded perspective view showing the electric excavator according to the first embodiment. [Figure 12] FIG. 12 is a side view showing the main body of the electric excavator according to the first embodiment. [Figure 13] FIG. 13 is a cross-sectional view showing the main body of the electric excavator according to the first embodiment. [Figure 14] FIG. 14 is a diagram illustrating the operation of the adjustment mechanism according to the first embodiment. [Figure 15] FIG. 15 is a side view for explaining a method of using the electric excavator according to the first embodiment. [Figure 16] FIG. 16 is a front perspective view showing the excavation system according to the second embodiment. [Figure 17] FIG. 17 is an exploded perspective view showing the excavation system according to the second embodiment, as viewed from the front. [Figure 18] FIG. 18 is a rear perspective view showing the excavation system according to the second embodiment. [Figure 19] FIG. 19 is an exploded perspective view showing the excavation system according to the second embodiment, as viewed from the rear. [Figure 20] FIG. 20 is a side view showing an electric excavator according to the second embodiment. [Figure 21] FIG. 21 is a top view showing the electric excavator according to the second embodiment. [Figure 22] FIG. 22 is a bottom view showing the electric excavator according to the second embodiment. [Figure 23] FIG. 23 is a front view showing the electric excavator according to the second embodiment. [Figure 24] FIG. 24 is a rear view showing the electric excavator according to the second embodiment. [Diagram 25] FIG. 25 is an exploded perspective view showing the electric excavator according to the second embodiment. [Figure 26] FIG. 26 is a side view for explaining a method of using the electric excavator according to the second embodiment. [Figure 27] FIG. 27 is a perspective view showing an electric excavator according to the third embodiment, as viewed from the front. [Figure 28] FIG. 28 is a perspective view showing the electric excavator according to the third embodiment, seen from the rear. [Figure 29] FIG. 29 is a top view showing the electric excavator according to the third embodiment. [Diagram 30] FIG. 30 is a bottom view showing the electric excavator according to the third embodiment. [Diagram 31] FIG. 31 is an exploded perspective view showing an electric excavator according to the third embodiment. [Diagram 32] FIG. 32 is a vertical sectional view showing an electric excavator according to the third embodiment. [Diagram 33] FIG. 33 is a cross-sectional view showing an electric excavator according to the third embodiment. [Diagram 34] FIG. 34 is a side view for explaining a method of using the electric excavator according to the third embodiment. [Diagram 35] FIG. 35 is a side view for explaining a method of using the electric excavator according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one or more embodiments, the electric drilling machine may include a motor, a motor housing that accommodates the motor, a reduction gear mechanism, a gear housing that is arranged below the motor housing and accommodates the reduction gear mechanism, a rotational output section that protrudes forward from the gear housing and rotates based on a rotational force transmitted from the motor via the reduction gear mechanism with a drill bit attached, a first contact member that is arranged to the left of the gear housing and contacts the first support surface, and a second contact member that is arranged to the right of the gear housing and contacts the second support surface.

[0010] In the above configuration, when the electric excavator is moved in the forward / backward direction to excavate the excavation target, the first contact member contacting the first support surface and the second contact member contacting the second support surface allow the operator to smoothly move the electric excavator in the forward / backward direction, so that the horizontal hole is formed in the excavation target with good workability.

[0011] In one or more embodiments, each of the first contact member and the second contact member may be supported by the gear housing.

[0012] In the above configuration, the first contact member and the second contact member supported by the gear housing enable the operator to smoothly move the electric excavator in the front-rear direction.

[0013] In one or more embodiments, the first contact member may include a first wheel rotatably supported on the gear housing, and the second contact member may include a second wheel rotatably supported on the gear housing.

[0014] In the above configuration, the first wheel rolling on the first support surface and the second wheel rolling on the second support surface enable the operator to smoothly move the electric excavator in the front-rear direction.

[0015] In one or more embodiments, the contact surface of the first wheel that contacts the first support surface and the contact surface of the second wheel that contacts the second support surface may each be positioned below a lower end of the gear housing.

[0016] In the above configuration, the first wheel can roll smoothly on the first support surface, and the second wheel can roll smoothly on the second support surface.

[0017] In one or more embodiments, the electric excavator may include a third wheel positioned forward of the first and second wheels and in contact with a third support surface.

[0018] In the above configuration, when the electric excavator is moved in the forward / rearward direction, the pitch motion of the electric excavator is suppressed. The pitch motion refers to the motion of the electric excavator swinging about a pitch axis extending in the left / right direction. When the electric excavator is moved forward so that the drill bit is pressed against an excavation target present in front of the electric excavator, the pitch motion is suppressed, so that the electric excavator can move forward in a straight line, and therefore, an appropriate horizontal hole can be formed in the excavation target with good workability.

[0019] In one or more embodiments, the third wheel may be located between the first wheel and the second wheel in the lateral direction.

[0020] With the above configuration, the electric excavator can move smoothly in the forward and backward directions by means of the three wheels.

[0021] In one or more embodiments, the drill bit may include a drilling shaft attached to the rotary output and a helical blade disposed about the drilling shaft. The third wheel may be disposed below the drilling shaft and aft of the helical blade.

[0022] In the above configuration, the third wheel can roll smoothly on the third support surface without interfering with the rotation of the drill bit.

[0023] In one or more embodiments, the third wheel may be supported on the gear housing via an arm member.

[0024] In the above configuration, the third wheel can roll on the third support surface while being supported by the gear housing via the arm member.

[0025] In one or more embodiments, the contact surface of the first wheel that contacts the first support surface and the contact surface of the second wheel that contacts the second support surface may each be positioned above a lower end of the gear housing.

[0026] In the above configuration, the electric excavator can move in the forward and backward directions while being suspended on the first support surface and the second support surface.

[0027] In one or more embodiments, the first wheel may include a first upper wheel and a first lower wheel disposed below the first upper wheel. The second wheel may include a second upper wheel and a second lower wheel disposed below the second upper wheel.

[0028] In the above configuration, the electric excavator can move smoothly in the front-rear direction. The pitch motion of the electric excavator is suppressed by the first upper wheel and the first lower wheel and the second upper wheel and the second lower wheel. The pitch motion refers to the motion of the electric excavator swinging about a pitch axis extending in the left-right direction. When the electric excavator is advanced so that the drill bit is pressed against an excavation target present in front of the electric excavator, the pitch motion is suppressed, so that the electric excavator can advance straight, and therefore an appropriate horizontal hole can be formed in the excavation target with good workability.

[0029] In one or more embodiments, at least one of the first upper wheel and the first lower wheel may be provided in a plurality of numbers in the front-rear direction. At least one of the second upper wheel and the second lower wheel may be provided in a plurality of numbers in the front-rear direction.

[0030] With the above configuration, the electric excavator can move smoothly in the forward and backward directions.

[0031] In one or more embodiments, one first upper wheel may be disposed, and two first lower wheels may be disposed in the front-rear direction. One second upper wheel may be disposed, and two second lower wheels may be disposed in the front-rear direction. The rotation shaft of the motor may extend in the up-down direction. The rotation shaft of the rear first lower wheel and the rotation shaft of the rear second lower wheel may each be disposed rearward of the rotation shaft of the motor, and the rotation shaft of the front first lower wheel and the rotation shaft of the front second lower wheel may each be disposed forward of the rotation shaft of the motor. In the front-rear direction, the first upper wheel may be disposed between the two first lower wheels. In the front-rear direction, the second upper wheel may be disposed between the two second lower wheels.

[0032] With the above configuration, the electric excavator can move smoothly in the forward and backward directions.

[0033] In one or more embodiments, the drilling system may include an electric drilling machine having a motor, a motor housing that accommodates the motor, a reduction mechanism, a gear housing arranged below the motor housing and accommodating the reduction mechanism, a rotational output section that protrudes forward from the gear housing and rotates based on a rotational force transmitted from the motor via the reduction mechanism with a drill bit attached, and a contact member, and a guide device that has a support surface with which the contact member contacts and guides the electric drilling machine in the forward and backward directions.

[0034] In the above-mentioned configuration, when the electric excavator is moved forward and backward to excavate the excavation target, the contact member that comes into contact with the support surface allows the operator to smoothly move the electric excavator forward and backward, so that the horizontal hole can be formed in the excavation target with good workability.

[0035] In one or more embodiments, the guide apparatus may include an adjustment mechanism for adjusting the height and tilt angle of the support surface.

[0036] In the above configuration, the height and inclination angle of the drill bit are adjusted by adjusting the height and inclination angle of the support surface.

[0037] In one or more embodiments, the contact member may include a first wheel disposed to the left of the gear housing, a second wheel disposed to the right of the gear housing, and a third wheel disposed forward of the gear housing. The support surface may be a flat surface disposed below a lower end of the gear housing. Each of the first wheel, the second wheel, and the third wheel may contact the support surface.

[0038] With the above configuration, the electric excavator can move smoothly in the forward and backward directions by means of the three wheels rolling on the supporting surface.

[0039] In one or more embodiments, the contact member may include a first upper wheel disposed to the left of the gear housing and a first lower wheel disposed below the first upper wheel, and a second upper wheel disposed to the right of the gear housing and a second lower wheel disposed below the second upper wheel. The support surfaces may include a first upper support surface with which the first upper wheel contacts, a first lower support surface with which the first lower wheel contacts, a second upper support surface with which the second upper wheel contacts, and a second lower support surface with which the second lower wheel contacts. Each of the first lower support surface and the second lower support surface may be disposed above a lower end of the gear housing.

[0040] In the above configuration, the electric excavator can move in the front-rear direction while being suspended between the first upper support surface and the first lower support surface and the second upper support surface and the second lower support surface.

[0041] In one or more embodiments, the electric drilling machine may include a motor, a motor housing that accommodates the motor, a reduction gear mechanism, a gear housing arranged below the motor housing and accommodating the reduction gear mechanism, a rotational output part that protrudes forward from the gear housing and rotates based on rotational force transmitted from the motor via the reduction gear mechanism, an adapter attached to the rotational output part, a drill bit supported on the adapter so as to be movable in the fore-and-aft direction, a support member that rotatably supports the drill bit and is movable in the fore-and-aft direction, and a handle connected to the support member.

[0042] In the above-mentioned configuration, the operator can move the drill bit in the forward and backward directions by moving the handle in the forward and backward directions, thereby forming a lateral hole in the excavation target with good workability.

[0043] In one or more embodiments, the handle may be supported on the gear housing for movement in a fore-and-aft direction.

[0044] In the above configuration, the handle can move smoothly in the front-rear direction while being supported by the gear housing.

[0045] In one or more embodiments, the drill assembly may include an adapter attached to a rotary output portion that protrudes forward from a gear housing of the electric drilling machine and rotates about a rotation axis extending in the fore-and-aft direction, a drill bit supported on the adapter so as to be movable in the fore-and-aft direction, a support member that rotatably supports the drill bit and is movable in the fore-and-aft direction, and a handle positioned rearward of the gear housing and connected to the support member.

[0046] In the above-mentioned configuration, the operator can move the drill bit in the forward and backward directions by moving the handle in the forward and backward directions, thereby forming a lateral hole in the excavation target with good workability.

[0047] In one or more embodiments, the drill assembly may include a rod member connecting the support member and the handle and slidably supported in the gear housing.

[0048] In the above-described configuration, the rod member is slidably supported by the gear housing, allowing the handle to move smoothly in the front-rear direction.

[0049] In one or more embodiments, the electric drilling machine may include a motor, a motor housing that accommodates the motor, a reduction mechanism, a gear housing that accommodates the reduction mechanism, a rotational output section that rotates based on a rotational force transmitted from the motor via the reduction mechanism with a drill bit attached, a first contact member that is arranged to the left of the gear housing and in contact with the first support surface, and a second contact member that is arranged to the right of the gear housing and in contact with the second support surface.

[0050] In the above configuration, when the electric excavator is moved to excavate the excavation target, the first contact member contacting the first support surface and the second contact member contacting the second support surface allow the operator to move the electric excavator smoothly, so that the horizontal hole is formed in the excavation target with good workability.

[0051] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiment. The components of the embodiments described below can be appropriately combined. In addition, some components may not be used.

[0052] In the embodiment, the positional relationship of each part will be described using the terms "left", "right", "front", "rear", "upper", and "lower". These terms refer to directions when working with the electric excavator. For example, when the electric excavator is sold at a hardware store or listed in a sales catalog, it is expected that the up-down direction will be reversed.

[0053] [First embodiment] A first embodiment will be described.

[0054] <Drilling System> FIG. 1 is a front perspective view showing the excavation system according to the present embodiment. FIG. 2 is an exploded front perspective view showing the excavation system according to the present embodiment. FIG. 3 is a rear perspective view showing the excavation system according to the present embodiment. FIG. 4 is an exploded rear perspective view showing the excavation system according to the present embodiment. FIG. 5 is a cross-sectional view showing the excavation system according to the present embodiment.

[0055] The excavation system includes an electric excavator 1A and a guide device 100 that guides the electric excavator 1A. The electric excavator 1A is a portable electric excavator that excavates an excavation target while being held by an operator, and forms a hole in the excavation target. In this embodiment, the excavation target is underground. The electric excavator 1A is used to form a horizontal hole in the ground.

[0056] The operator presses the front end 19U of the rotating drill bit 19 against the excavation target located in front of the electric excavator 1A. With the rotating drill bit 19 pressed against the excavation target, the electric excavator 1A is moved forward, whereby the excavation target is excavated and a horizontal hole is formed in the excavation target. When discharging the excavated material from the horizontal hole formed in the excavation target, the operator pulls the electric excavator 1A backward. The guide device 100 guides the electric excavator 1A in the forward and backward directions. The guide device 100 allows the electric excavator 1A to move smoothly in the forward and backward directions.

[0057] Fig. 6 is a side view showing the electric excavator 1A according to this embodiment. Fig. 7 is a top view showing the electric excavator 1A according to this embodiment. Fig. 8 is a bottom view showing the electric excavator 1A according to this embodiment. Fig. 9 is a front view showing the electric excavator 1A according to this embodiment. Fig. 10 is a rear view showing the electric excavator 1A according to this embodiment. Fig. 11 is an exploded perspective view showing the electric excavator 1A according to this embodiment.

[0058] The electric drilling machine 1A includes a main body 6, a drill bit 19, a first wheel 21, a second wheel 22, and a third wheel 23. Note that Fig. 9 shows the electric drilling machine 1A with the drill bit 19 removed.

[0059] Fig. 12 is a side view showing the main body 6 of the electric excavator 1A according to this embodiment. Fig. 13 is a cross-sectional view showing the main body 6 of the electric excavator 1A according to this embodiment.

[0060] As shown in Figures 1 to 13, the main body 6 includes a motor housing 2, a handle housing 3, a gear housing 4, a battery attachment section 7, a controller 13, a main switch 10, a trigger switch 11, a forward / reverse rotation switch lever 9, a speed switch lever 15, a motor 8, a reduction mechanism 14, and a rotation output section 5.

[0061] The motor housing 2 accommodates the motor 8. The motor housing 2 is tubular and long in the vertical direction. The motor housing 2 is made of synthetic resin. The motor housing 2 has an exhaust port 2E that connects the internal space of the motor housing 2 to the external space. The exhaust ports 2E are provided on the left, right, and front of the motor housing 2. Air in the internal space of the motor housing 2 is exhausted to the external space via the exhaust port 2E.

[0062] The handle housing 3 is disposed above the motor housing 2. A lower portion of the handle housing 3 is connected to an upper portion of the motor housing 2. The handle housing 3 is in the form of a long loop extending in the vertical direction. The handle housing 3 is made of synthetic resin.

[0063] The handle housing 3 has an under part 3A connected to the upper part of the motor housing 2, a first handle part 3B extending upward from the rear part of the under part 3A, a second handle part 3C extending upward from the front part of the under part 3A, and a battery holding housing part 3D connecting the upper end part of the first handle part 3B and the upper end part of the second handle part 3C. The first handle part 3B is connected to each of the motor housing 2 and the battery holding housing part 3D. The second handle part 3C is connected to each of the motor housing 2 and the battery holding housing part 3D. The first handle part 3B and the second handle part 3C are connected to the motor housing 2 via the under part 3A. The second handle part 3C is disposed forward of the first handle part 3B. The first handle part 3B and the second handle part 3C are disposed above the motor housing 2. The operator can hold the first handle part 3B with his / her hand. An air intake 3F is provided in front of the second handle part 3C.

[0064] The gear housing 4 accommodates the reduction gear mechanism 14. The gear housing 4 is tubular and long in the vertical direction. The gear housing 4 is disposed below the motor housing 2. An upper portion of the gear housing 4 is connected to a lower portion of the motor housing 2. The gear housing 4 is made of aluminum. At least a portion of the surface of the gear housing 4 is covered with a cover 4A. In this embodiment, the cover 4A has a two-layer structure of synthetic resin and elastomer.

[0065] A screw hole 16 is provided in each of the left and right parts of the gear housing 4. A screw hole 18 is provided in each of the left and right parts of the gear housing 4. The screw hole 18 is provided rearward and below the screw hole 16. In the vertical direction, the position of the screw hole 18 and the position of the rotation output portion 5 are substantially the same.

[0066] The battery attachment section 7 is provided above the handle housing 3. The battery attachment section 7 is provided in the battery holding housing section 3D. A battery pack 17 is attached to the battery attachment section 7. The battery attachment section 7 functions as a power supply section that supplies power to the motor 8.

[0067] In this embodiment, two battery mounting sections 7 are provided in the front-rear direction. A battery pack 17 is mounted in each of the two battery mounting sections 7, so that two battery packs 17 are arranged in the front-rear direction. The battery packs 17 are detachable from the battery mounting sections 7. When mounted in the battery mounting sections 7, the battery packs 17 can supply power to the electric excavator 1A. The battery packs 17 include a secondary battery. In this embodiment, the battery packs 17 include a rechargeable lithium-ion battery.

[0068] The controller 13 outputs a control signal for controlling the electric excavator 1A. The second handle portion 3C has an internal space capable of housing the controller 13. The controller 13 is housed in the second handle portion 3C.

[0069] The main switch 10 is operated by an operator to start the electric excavator 1A. The main switch 10 is provided at the rear of the under part 3A. By operating the main switch 10, power is supplied from the battery pack 17 to the controller 13, and the electric excavator 1A starts up. By operating the main switch 10, the electric excavator 1A is switched between driving and stopping.

[0070] The trigger switch 11 is operated by an operator to start the motor 8. The trigger switch 11 is provided on the handle housing 3. The trigger switch 11 includes a trigger lever 11A and a switch circuit 11B. The trigger lever 11A is operated by an operator to start the motor 8.

[0071] In this embodiment, the trigger switch 11 including a trigger lever 11A and a switch circuit 11B is provided on the first handle portion 3B. The trigger lever 11A is disposed so as to protrude forward from the front portion of the first handle portion 3B. While gripping the first handle portion 3B with one of the left and right hands, the operator can pull the trigger lever 11A backward with a finger so that the trigger lever 11A moves backward. When the trigger lever 11A is pulled backward, the motor 8 is started. The trigger lever 11A is biased forward by a biasing member. When the pulling operation of the trigger lever 11A is released, the trigger lever 11A moves forward and the motor 8 stops.

[0072] The first handle portion 3B has an internal space capable of accommodating the switch circuit 11B. The switch circuit 11B is accommodated in the first handle portion 3B. The switch circuit 11B outputs an operation signal when the trigger lever 11A is pulled. When the electric excavator 1A is in an activated state, pulling the trigger lever 11A rearward supplies power to the motor 8 from the battery pack 17, and the motor 8 starts. The motor 8 is driven based on the operation signal output from the switch circuit 11B. The motor 8 is switched between being driven and being stopped by switching between operating and releasing the trigger lever 11A.

[0073] In the vertical direction, the trigger lever 11A is disposed below the center of the handle housing 3. In this embodiment, the trigger lever 11A is disposed so as to protrude forward from the front part of the lower part of the first handle portion 3B in the vertical direction. Like the trigger lever 11A, the switch circuit 11B is disposed below the center of the first handle portion 3B in the vertical direction.

[0074] The forward / reverse switching lever 9 is operated by an operator to switch the rotation direction of the motor 8. By operating the forward / reverse switching lever 9 left or right, the rotation direction of the motor 8 is switched between the forward direction and the reverse direction. By switching the rotation direction of the motor 8, the rotation direction of the rotation output unit 5 is switched between the forward direction and the reverse direction.

[0075] In this embodiment, the forward / reverse rotation switching lever 9 is disposed below the trigger lever 11 A. The forward / reverse rotation switching lever 9 is disposed in the under portion 3A.

[0076] The speed change lever 15 is operated by an operator to change the rotation speed of the rotation output part 5. The speed change lever 15 is provided at the front part of the gear housing 4. By operating the speed change lever 15 in the up or down direction, the rotation speed of the rotation output part 5 is changed between a first speed and a second speed which is higher than the first speed.

[0077] The motor 8 generates a rotational force for rotating the rotation output unit 5. The motor 8 is driven based on the 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, a rotor 82 disposed inside the stator 81, and a rotor shaft 80 fixed to the rotor 82. A motor rotation axis MX indicating the rotation axis of the rotor 82 extends in the vertical direction. The rotor 82 rotates around the motor rotation axis MX extending in the vertical direction.

[0078] Stator 81 has a stator core including a plurality of laminated steel plates, an insulator fixed to the stator core, and a plurality of coils wound around the stator core with the insulator interposed therebetween.

[0079] The rotor 82 has a cylindrical rotor core disposed around the rotor shaft 80, and a plurality of permanent magnets held by the rotor core. A lower portion of the rotor shaft 80 is rotatably supported by a bearing 83. An upper portion of the rotor shaft 80 is rotatably supported by a bearing 84.

[0080] A sensor circuit board 79 is disposed above the stator 81. The rotation of the rotor 82 is detected by a rotation detection element provided on the sensor circuit board 79. The controller 13 controls the drive current supplied to the motor 8 based on a detection signal from the rotation detection element.

[0081] A centrifugal fan 85 is attached to the rotor shaft 80 between the bearing 83 and the stator 81. The exhaust port 2E of the motor housing 2 is disposed in a part of the periphery of the centrifugal fan 85. When the rotor shaft 80 rotates and the centrifugal fan 85 rotates, the air around the electric excavator 1A flows into the internal space of the handle housing 3 and the internal space of the motor housing 2 through the intake port 3F. The air that has flowed into the internal space of the handle housing 3 and the internal space of the motor housing 2 cools the controller 13 and the motor 8, and is then discharged to the external space of the motor housing 2 through the exhaust port 2E.

[0082] A pinion gear 140 is provided at the lower end of the rotor shaft 80. The pinion gear 140 is disposed in the internal space of the gear housing 4. The rotor shaft 80 is connected to the reduction gear mechanism 14 via the pinion gear 140.

[0083] The reduction gear mechanism 14 transmits the rotational force generated by the motor 8 to the rotation output unit 5. The reduction gear mechanism 14 transmits the rotational force from the rotor shaft 80 to the rotation output unit 5. The reduction gear mechanism 14 includes a plurality of gears. The reduction gear mechanism 14 has a first planetary gear mechanism 141, a second planetary gear mechanism 142, an intermediate shaft 143, and an output shaft 144. The rotation axis of the rotor shaft 80, the rotation axis of the intermediate shaft 143, and the rotation axis of the output shaft 144 coincide with each other.

[0084] The first planetary gear mechanism 141 is disposed below the rotor shaft 80. The intermediate shaft 143 is disposed below the first planetary gear mechanism 141. The second planetary gear mechanism 142 is disposed below the intermediate shaft 143. The output shaft 144 is disposed below the second planetary gear mechanism 142.

[0085] A pinion gear 140 provided at the lower end of the rotor shaft 80 functions as a sun gear of a first planetary gear mechanism 141. The second planetary gear mechanism 142 is disposed below the first planetary gear mechanism 141. The first planetary gear mechanism 141 is connected to the second planetary gear mechanism 142 via an intermediate shaft 143. A sun gear of the second planetary gear mechanism 142 is provided at the lower end of the intermediate shaft 143. The rotation reduced by the first planetary gear mechanism 141 is further reduced by the second planetary gear mechanism 142. The rotation of the second planetary gear mechanism 142 rotates an output shaft 144.

[0086] The output shaft 144 is rotatably supported by a bearing 145. A bevel gear 146 is provided at the lower end of the output shaft 144. The lower end of the output shaft 144 is connected to the rotation output unit 5 via the bevel gear 146.

[0087] The rotation output part 5 rotates based on the rotational force transmitted from the motor 8 via the reduction mechanism 14. The rotation output part 5 protrudes forward from the lower part of the gear housing 4. A drill bit 19 is attached to the rotation output part 5. The rotation output part 5 is rotatable with the drill bit 19 attached. An output rotation axis DX indicating the rotation axis of the rotation output part 5 extends in the front-rear direction. The rotation output part 5 rotates around the output rotation axis DX. The motor rotation axis MX of the rotor 82 and the output rotation axis DX of the rotation output part 5 are perpendicular to each other.

[0088] The rotary output unit 5 includes a spindle 51 and a drill chuck 52 attached to the front end of the spindle 51. The drill chuck 52 has an insertion hole 52A into which the drill bit 19 is inserted. The insertion hole 52A is formed so as to extend rearward from the front end of the drill chuck 52. The drill chuck 52 is rotatable with the drill bit 19 attached thereto.

[0089] The spindle 51 is rotatably supported by a needle bearing 53 and a ball bearing 54. The needle bearing 53 rotatably supports the rear end of the spindle 51. The ball bearing 54 rotatably supports the front portion of the spindle 51.

[0090] A bevel gear 55 is provided at the rear of the spindle 51. The bevel gear 55 meshes with a bevel gear 146 of the output shaft 144.

[0091] The drill bit 19 is attached to the rotary output unit 5. The drill bit 19 is a drill bit for drilling called an earth auger drill bit. As shown in FIG. 2, the drill bit 19 has a drilling shaft 19A, a drilling double helix blade 19B, a tip bit 19C, and two cutting blades 19D.

[0092] The drilling shaft 19A extends in the front-rear direction. The drilling shaft 19A is attached to the rotary output part 5. When attaching the drill bit 19 to the rotary output part 5, an adapter 5A is inserted into the insertion hole 52A of the drill chuck 52. The adapter 5A is a rod-shaped member. A hole into which the adapter 5A is inserted is provided at the rear end of the drilling shaft 19A. With the adapter 5A inserted into the hole at the rear end of the drilling shaft 19A, the rear end of the drilling shaft 19A and the adapter 5A are fixed by a fixing device 5B. The rear end of the drilling shaft 19A is attached to the drill chuck 52 via the adapter 5A.

[0093] The drilling double helix blade 19B is arranged in a double spiral shape around the drilling shaft 19A. The drilling double helix blade 19B is fixed to the drilling shaft 19A. The tip bit 19C is arranged at the front end of the drilling shaft 19A. Each of the two cutting blades 19D is arranged at the front end of the drilling double helix blade 19B.

[0094] The first wheel 21 is disposed to the left of the gear housing 4. The first wheel 21 is rotatably supported by the gear housing 4. A first axle 24 is fixed to a left portion of the gear housing 4. The first axle 24 protrudes leftward from the left portion of the gear housing 4. The first wheel 21 is rotatably supported by the first axle 24. The first wheel 21 rotates about a rotation axis AX1 extending in the left-right direction.

[0095] A threaded portion is provided on the right end portion of the first axle 24. The threaded portion of the first axle 24 is inserted into a threaded hole 16 provided in the left portion of the gear housing 4. The first axle 24 is fixed to the left portion of the gear housing 4 by engaging the threaded portion of the first axle 24 with the threaded hole 16 provided in the left portion of the gear housing 4. The first wheel 21 is rotatably supported by the gear housing 4 via the first axle 24.

[0096] The second wheel 22 is disposed to the right of the gear housing 4. The second wheel 22 is rotatably supported by the gear housing 4. A second axle 25 is fixed to the right portion of the gear housing 4. The second axle 25 protrudes rightward from the right portion of the gear housing 4. The second wheel 22 is rotatably supported by the second axle 25. The second wheel 22 rotates about a rotation axis AX2 extending in the left-right direction.

[0097] The rotation axis AX1 of the first wheel 21 and the rotation axis AX2 of the second wheel 22 coincide with each other.

[0098] A threaded portion is provided on the left end portion of the second axle 25. The threaded portion of the second axle 25 is inserted into a threaded hole 16 provided in the right portion of the gear housing 4. The second axle 25 is fixed to the right portion of the gear housing 4 by engaging the threaded portion of the second axle 25 with the threaded hole 16 provided in the right portion of the gear housing 4. The second wheel 22 is rotatably supported by the gear housing 4 via the second axle 25.

[0099] The third wheel 23 is disposed forward of the first wheel 21 and the second wheel 22. The third wheel 23 is disposed forward of the gear housing 4. The third wheel 23 is disposed between the first wheel 21 and the second wheel 22 in the left-right direction. The third wheel 23 is rotatably supported by the gear housing 4. An arm member 26 is fixed to the gear housing 4. The arm member 26 protrudes forward from the gear housing 4. The third wheel 23 is rotatably supported by the arm member 26. The third wheel 23 rotates about a rotation axis AX3 extending in the left-right direction.

[0100] The arm member 26 has a left arm portion extending forward from the left part of the gear housing 4, a right arm portion extending forward from the right part of the gear housing 4, and a support portion connecting the front end of the left arm portion and the front end of the right arm portion. The third wheel 23 is rotatably supported by the support portion of the arm member 26. The rear end of the left arm portion is fixed to the gear housing 4 by a screw inserted into a screw hole 18 provided in the left part of the gear housing 4. The rear end of the right arm portion is fixed to the gear housing 4 by a screw inserted into a screw hole 18 provided in the right part of the gear housing 4. That is, the arm member 26 is fixed to the gear housing 4 by a screw inserted into the screw hole 18. The third wheel 23 is rotatably supported by the gear housing 4 via the arm member 26.

[0101] The third wheel 23 is disposed below the excavation shaft 19A and behind the excavation double helix blade 19B.

[0102] A lower portion of the first wheel 21 is disposed below the lower end portion of the gear housing 4. A lower portion of the second wheel 22 is disposed below the lower end portion of the gear housing 4. A lower portion of the third wheel 23 is disposed below the lower end portion of the gear housing 4.

[0103] A rear handle 27 is fixed to the gear housing 4. At least a part of the rear handle 27 protrudes rearward from the gear housing 4. The rear handle 27 is fixed to the gear housing 4 by a screw. The screw for fixing the rear handle 27 to the gear housing 4 is inserted into the screw hole 18. In this embodiment, the rear handle 27 is integral with the arm member 26. The rear handle 27 has a first handle portion extending rearward from the rear end of the left arm portion of the arm member 26, a second handle portion extending rearward from the rear end of the right arm portion of the arm member 26, and a grip portion connecting the rear end of the first handle portion and the rear end of the second handle portion. The grip portion of the rear handle 27 is disposed rearward of the gear housing 4. The rear handle 27 may be separate from the arm member 26.

[0104] The guide device 100 has a base plate 101 , a left wall 102 , a right wall 103 , and a spike 104 .

[0105] The base plate 101 has a rectangular shape that is long in the front-rear direction. The base plate 101 is a flat plate that is long in the front-rear direction. The base plate 101 has a support surface 101A that faces upward. The support surface 101A is a flat surface. The electric excavator 1A travels in the front-rear direction on the support surface 101A. Each of the first wheel 21, the second wheel 22, and the third wheel 23 contacts the support surface 101A.

[0106] The first wheel 21, the second wheel 22, and the third wheel 23 contact the support surface 101A simultaneously. The contact surface (ground contact surface) of the first wheel 21 that contacts the support surface 101A, the contact surface (ground contact surface) of the second wheel 22 that contacts the support surface 101A, and the contact surface (ground contact surface) of the third wheel 23 that contacts the support surface 101A are each located below the lower end of the gear housing 4.

[0107] When the first wheel 21, the second wheel 22, and the third wheel 23 are in contact with the support surface 101A, a gap is formed between the lower end of the gear housing 4 and the support surface 101A. In other words, when the first wheel 21, the second wheel 22, and the third wheel 23 are in contact with the support surface 101A, the gear housing 4 does not contact the support surface 101A. The support surface 101A is disposed below the lower end of the gear housing 4.

[0108] When the first wheel 21, the second wheel 22, and the third wheel 23 are in contact with the support surface 101A, the output rotation axis DX of the rotation output unit 5 and the rotation axis of the drill bit 19 are parallel to the support surface 101A. When the first wheel 21, the second wheel 22, and the third wheel 23 are in contact with the support surface 101A, a gap is formed between the lower end of the drill bit 19 and the support surface 101A. In other words, when the first wheel 21, the second wheel 22, and the third wheel 23 are in contact with the support surface 101A, the drill bit 19 does not contact the support surface 101A.

[0109] The left wall 102 is provided at the left end of the base plate 101. The left wall 102 protrudes upward from the left end of the base plate 101. In the front-rear direction, the dimensions of the left wall 102 and the dimensions of the base plate 101 are the same. In the front-rear direction, the position of the front end of the left wall 102 and the position of the front end of the base plate 101 coincide with each other. In the front-rear direction, the position of the rear end of the left wall 102 and the position of the rear end of the base plate 101 coincide with each other. The left wall 102 prevents the first wheel 21 from departing leftward from the support surface 101A of the base plate 101.

[0110] The right wall 103 is provided at the right end of the base plate 101. The right wall 103 protrudes upward from the right end of the base plate 101. In the front-rear direction, the dimensions of the right wall 103 and the dimensions of the base plate 101 are the same. In the front-rear direction, the position of the front end of the right wall 103 and the position of the front end of the base plate 101 coincide with each other. In the front-rear direction, the position of the rear end of the right wall 103 and the position of the rear end of the base plate 101 coincide with each other. The right wall 103 prevents the second wheel 22 from departing to the right from the support surface 101A of the base plate 101.

[0111] The spikes 104 protrude downward from the base plate 101. A plurality of spikes 104 are provided. In this embodiment, the spikes 104 are disposed at each of the four corners of the base plate 101. The spikes 104 are stuck into the ground. The two left spikes 104 are held by a spike holder provided on the left wall 102. The two right spikes 104 are held by a spike holder provided on the right wall 103.

[0112] The amount by which the spikes 104 protrude from the underside of the base plate 101 is adjustable. A threaded portion is provided on the top of the spikes 104. A thread groove is provided inside the spike holder. The amount by which the spikes 104 protrude downward from the base plate 101 is adjusted by rotating the spikes 104 relative to the spike holder. The height and inclination angle of the support surface 101A are adjusted by adjusting the amount by which each of the multiple spikes 104 protrudes. The spikes 104 function as an adjustment mechanism that adjusts the height and inclination angle of the support surface 101A.

[0113] Fig. 14 is a diagram showing the operation of the adjustment mechanism according to this embodiment. As shown in Fig. 14, when the guide device 100 is placed on the ground parallel to a horizontal plane, the spikes 104 are adjusted so that the protruding amounts of the four spikes 104 are the same, and the support surface 101A is in a horizontal state parallel to the horizontal plane. For example, the spikes 104 are adjusted so that the protruding amounts of the two front spikes 104 are greater than the protruding amounts of the two rear spikes 104, and the support surface 101A is in an inclined state inclined upward toward the front.

[0114] <How to use> Next, a method of using the electric excavator 1A according to this embodiment will be described. Figure 15 is a side view for explaining a method of using the electric excavator 1A according to this embodiment.

[0115] The electric excavator 1A is used to form a horizontal hole in an excavation target. The electric excavator 1A is used with the motor housing 2 disposed above the gear housing 4. That is, the electric excavator 1A is used in a vertically placed state.

[0116] The guide device 100 is placed on the ground at the work site so that the spikes 104 are stuck into the ground at the work site. The electric excavator 1A is placed on the guide device 100. The first wheel 21, the second wheel 22, and the third wheel 23 each come into contact with the support surface 101A, so that the electric excavator 1A is placed vertically.

[0117] The operator holds the electric excavator 1A so that the motor housing 2 is located above the gear housing 4. In the example shown in Fig. 15, the operator holds the first handle portion 3B with his right hand and holds the rear handle 27 with his left hand.

[0118] The operator pulls the trigger lever 11A with the fingers of his / her right hand gripping the first handle portion 3B. By pulling the trigger lever 11A, the rotation output part 5 rotates with the drill bit 19 attached thereto.

[0119] The operator moves the electric excavator 1A forward relative to the guide device 100 so that the front end portion 19U of the rotating drill bit 19 is pressed against the excavation target present in front of the electric excavator 1A. The first wheel 21, the second wheel 22, and the third wheel 23 each roll on the support surface 101A, thereby allowing the electric excavator 1A to move forward.

[0120] The rotating drill bit 19 is pressed against the target to be excavated, and the target is excavated to form a lateral hole in the target. With the drill bit 19 rotating, the electric drilling machine 1A is pushed forward by the operator to progress the formation of the lateral hole.

[0121] In order to discharge the excavated material from the horizontal hole formed in the excavation target, the operator moves the electric excavator 1A backward relative to the guide device 100 at any timing so that the drill bit 19 is pulled out from the excavation target. The electric excavator 1A can move backward by the first wheel 21, the second wheel 22, and the third wheel 23 each rolling on the support surface 101A.

[0122] As the electric drilling machine 1A is moved backward, the drill bit 19 is pulled out of the drilling target, and the drilled material is discharged from the horizontal hole formed in the drilling target.

[0123] While rotating the drill bit 19, the operator repeats the action of moving the electric excavator 1A forward so that the body 6 of the electric excavator 1A approaches the excavation target, and the action of moving the electric excavator 1A backward so that the body 6 of the electric excavator 1A moves away from the excavation target. As the electric excavator 1A moves forward, the excavation target is excavated by the drill bit 19, and the formation of the horizontal hole progresses. As the electric excavator 1A moves backward, the excavated material is discharged from the horizontal hole in the excavation target. As the electric excavator 1A moves forward and backward repeatedly, the excavation of the excavation target and the discharge of the excavated material are repeated, and the horizontal hole is formed in the excavation target. The guide device 100 allows the electric excavator 1A to smoothly repeat forward and backward movements.

[0124] <Effects> As described above, the electric drilling machine 1A may include a motor 8, a motor housing 2 that accommodates the motor 8, a reduction gear mechanism 14, a gear housing 4 that is arranged below the motor housing 2 and accommodates the reduction gear mechanism 14, a rotational output section 5 that protrudes forward from the gear housing 4 and rotates based on the rotational force transmitted from the motor 8 via the reduction gear mechanism 14 with a drill bit 19 attached, a first wheel 21 that is arranged to the left of the gear housing 4 and is a first contact member that contacts the support surface 101A, and a second wheel 22 that is arranged to the right of the gear housing 4 and is a second contact member that contacts the support surface 101A.

[0125] In the above configuration, when the electric excavator 1A is moved in the forward / backward direction to excavate the excavation target, the first wheel 21 contacting the support surface 101A and the second wheel 22 contacting the support surface 101A allow the operator to smoothly move the electric excavator 1A in the forward / backward direction. Therefore, a horizontal hole is formed in the excavation target with good workability.

[0126] In this embodiment, each of the first wheel 21 and the second wheel 22 may be supported by the gear housing 4.

[0127] In the above configuration, the first wheel 21 and the second wheel 22 supported by the gear housing 4 enable the operator to smoothly move the electric excavator 1A in the front-rear direction.

[0128] In this embodiment, the first wheel 21 may be rotatably supported on the gear housing 4, and the second wheel 22 may be rotatably supported on the gear housing 4.

[0129] In the above configuration, the first wheel 21 rolling on the support surface 101A and the second wheel 22 rolling on the support surface 101A enable the operator to smoothly move the electric excavator 1A in the front-rear direction.

[0130] In this embodiment, the contact surface of the first wheel 21 that contacts the support surface 101A and the contact surface of the second wheel 22 that contacts the support surface 101A may be disposed below the lower end of the gear housing 4.

[0131] In the above configuration, the first wheel 21 can roll smoothly on the support surface 101A, and the second wheel 22 can roll smoothly on the support surface 101A.

[0132] In this embodiment, the electric excavator 1A may include a third wheel 23 that is disposed forward of the first wheel 21 and the second wheel 22 and that comes into contact with the support surface 101A.

[0133] In the above configuration, when the electric excavator 1A is moved in the forward / rearward direction, the pitch motion of the electric excavator 1A is suppressed. The pitch motion refers to the motion of the electric excavator 1A swinging about a pitch axis extending in the left / right direction. When the electric excavator 1A is advanced so that the drill bit 19 is pressed against an excavation target present in front of the electric excavator 1A, the pitch motion is suppressed, so that the electric excavator 1A can advance straight, and therefore, an appropriate horizontal hole can be formed in the excavation target with good workability.

[0134] In this embodiment, the third wheel 23 may be disposed between the first wheel 21 and the second wheel 22 in the left-right direction.

[0135] In the above configuration, the electric excavator 1A can move smoothly in the front-rear direction by the three wheels (21, 22, 23).

[0136] In this embodiment, the drill bit 19 may include a drilling shaft 19A attached to the rotary output 5 and a drilling double helix blade 19B disposed around the drilling shaft 19A. The third wheel 23 may be disposed below the drilling shaft 19A and behind the drilling double helix blade 19B.

[0137] In the above configuration, the third wheel 23 can smoothly roll on the support surface 101A without interfering with the rotation of the drill bit 19.

[0138] In this embodiment, the third wheel 23 may be supported on the gear housing 4 via an arm member 26 .

[0139] In the above configuration, the third wheel 23 is supported by the gear housing 4 via the arm member 26 and can roll on the support surface 101A.

[0140] In this embodiment, the excavation system may include an electric excavator 1A and a guide device 100 that has a support surface 101A with which three wheels (21, 22, 23) that are contact members of the electric excavator 1A come into contact and that guides the electric excavator 1A in the forward and backward directions.

[0141] In the above configuration, when the electric excavator 1A is moved in the front-rear direction to excavate the excavation target, the contact member that comes into contact with the support surface 101A allows the operator to smoothly move the electric excavator 1A in the front-rear direction, so that the horizontal hole can be formed in the excavation target with good workability.

[0142] In this embodiment, the guide device 100 may have a plurality of spikes 104 that are adjustment mechanisms for adjusting the height and inclination angle of the support surface 101A.

[0143] In the above configuration, the height and inclination angle of the drill bit 19 are adjusted by adjusting the height and inclination angle of the support surface 101A.

[0144] [Second embodiment] A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0145] <Electric excavator> FIG. 16 is a front perspective view showing the excavation system according to this embodiment. FIG. 17 is an exploded front perspective view showing the excavation system according to this embodiment. FIG. 18 is a rear perspective view showing the excavation system according to this embodiment. FIG. 19 is an exploded rear perspective view showing the excavation system according to this embodiment. FIG. 20 is a side view showing the electric excavator 1B according to this embodiment. FIG. 21 is a top view showing the electric excavator 1B according to this embodiment. FIG. 22 is a bottom view showing the electric excavator 1B according to this embodiment. FIG. 23 is a front view showing the electric excavator 1B according to this embodiment. FIG. 24 is a rear view showing the electric excavator 1B according to this embodiment. FIG. 25 is an exploded perspective view showing the electric excavator 1B according to this embodiment.

[0146] In this embodiment, the guide device 110 has a base plate 111, a left wall 112 protruding upward from the left end of the base plate 111, a right wall 113 protruding upward from the right end of the base plate 111, and spikes 114 protruding downward from each of the four corners of the base plate 111.

[0147] The left wall 112 has a right surface facing the right wall 113. A first groove 115 is provided on the right surface of the left wall 112. The first groove 115 is formed so as to be recessed leftward from the right surface of the left wall 112. The first groove 115 is long in the front-rear direction. The first groove 115 includes a first upper groove 115A and a first lower groove 115B provided below the first upper groove 115A. Each of the first upper groove 115A and the first lower groove 115B is formed so as to be recessed leftward from the right surface of the left wall 112. Each of the first upper groove 115A and the first lower groove 115B is long in the front-rear direction.

[0148] The right wall 113 has a left surface facing the left wall 112. A second groove 116 is provided on the left surface of the right wall 113. The second groove 116 is formed so as to be recessed to the right from the left surface of the right wall 113. The second groove 116 is long in the front-rear direction. The second groove 116 includes a second upper groove 116A and a second lower groove 116B provided below the second upper groove 116A. Each of the second upper groove 116A and the second lower groove 116B is formed so as to be recessed to the right from the left surface of the right wall 113. Each of the second upper groove 116A and the second lower groove 116B is long in the front-rear direction.

[0149] The electric excavator 1B includes a first wheel 31 disposed to the left of the gear housing 4 and a second wheel 32 disposed to the right of the gear housing 4. The first wheel 31 and the second wheel 32 are each rotatably supported by the gear housing 4.

[0150] In this embodiment, a first support member 34 is fixed to the left part of the gear housing 4. The first support member 34 is fixed to the gear housing 4 by a first screw 36. The first screw 36 is inserted into a screw hole 16 provided in the left part of the gear housing 4 through an opening provided in the first support member 34. The first support member 34 is fixed to the left part of the gear housing 4 by the first screw 36 inserted into the screw hole 16 provided in the left part of the gear housing 4. The first wheel 31 is rotatably supported by the first support member 34. A plurality of first wheels 31 are provided. Each of the plurality of first wheels 31 rotates around a rotation axis AX5 extending in the left-right direction. Each of the plurality of first wheels 31 is rotatably supported by the gear housing 4 via the first support member 34.

[0151] In this embodiment, a second support member 35 is fixed to the right part of the gear housing 4. The second support member 35 is fixed to the gear housing 4 by a second screw 37. The second screw 37 is inserted into a screw hole 16 provided in the right part of the gear housing 4 through an opening provided in the second support member 35. The second support member 35 is fixed to the right part of the gear housing 4 by the second screw 37 inserted into the screw hole 16 provided in the right part of the gear housing 4. The second wheel 32 is rotatably supported by the second support member 35. A plurality of second wheels 32 are provided. Each of the plurality of second wheels 32 rotates around a rotation axis AX6 extending in the left-right direction. Each of the plurality of second wheels 32 is rotatably supported by the gear housing 4 via the second support member 35.

[0152] In this embodiment, a lower portion of the first wheel 31 is disposed above a lower end portion of the gear housing 4. A lower portion of the second wheel 32 is disposed above a lower end portion of the gear housing 4.

[0153] In this embodiment, the first wheels 31 include a first upper wheel 31A and a first lower wheel 31B disposed below the first upper wheel 31A. The second wheels 32 include a second upper wheel 32A and a second lower wheel 32B disposed below the second upper wheel 32A.

[0154] At least one of the first upper wheel 31A and the first lower wheel 31B is provided in a plurality in the front-rear direction. In this embodiment, one first upper wheel 31A is provided. Two first lower wheels 31B are provided in the front-rear direction.

[0155] At least one of the second upper wheel 32A and the second lower wheel 32B is provided in a plurality of numbers in the front-rear direction. In this embodiment, one second upper wheel 32A is provided. Two second lower wheels 32B are provided in the front-rear direction.

[0156] The rotation axis AX5 of the first upper wheel 31A and the rotation axis AX6 of the second upper wheel 32A coincide with each other. The rotation axis AX5 of the rear first lower wheel 31B and the rotation axis AX6 of the rear second lower wheel 32B coincide with each other. The rotation axis AX5 of the front first lower wheel 31B and the rotation axis AX6 of the front second lower wheel 32B coincide with each other.

[0157] The motor rotation axis MX, which indicates the rotation axis of the motor 8, extends in the vertical direction. The rotation axis AX5 of the rear first lower wheel 31B and the rotation axis AX6 of the rear second lower wheel 32B are each disposed rearward of the motor rotation axis MX. The rotation axis AX5 of the front first lower wheel 31B and the rotation axis AX6 of the front second lower wheel 32B are each disposed forward of the motor rotation axis MX. In the front-rear direction, the first upper wheel 31A is disposed between the two first lower wheels 31B. In the front-rear direction, the second upper wheel 32A is disposed between the two second lower wheels 32B. That is, the three first wheels 31 are disposed one at each of the vertices of a triangle. The three second wheels 32 are disposed one at each of the vertices of a triangle.

[0158] In this embodiment, the first wheel 31 rolls in the front-rear direction inside the first groove 115. The second wheel 32 rolls in the front-rear direction inside the second groove .

[0159] The first upper wheel 31A rolls in the front-rear direction inside the first upper groove 115A. The first upper groove 115A has a support surface 115C (first upper support surface) that supports the first upper wheel 31A. The support surface 115C faces upward. The lower end of the first upper wheel 31A contacts the support surface 115C. The contact surface of the first upper wheel 31A that contacts the support surface 115C is positioned above the lower end of the gear housing 4.

[0160] The first lower wheel 31B rolls in the front-rear direction inside the first lower groove 115B. The first lower groove 115B has a support surface 115D (first lower support surface) that supports the first lower wheel 31B. The support surface 115D faces upward. The lower end of the first lower wheel 31B contacts the support surface 115D. The contact surface of the first lower wheel 31B that contacts the support surface 115D is positioned above the lower end of the gear housing 4.

[0161] The second upper wheel 32A rolls in the front-rear direction inside the second upper groove 116A. The second upper groove 116A has a support surface 116C (second upper support surface) that supports the second upper wheel 32A. The support surface 116C faces upward. The lower end of the second upper wheel 32A contacts the support surface 116C. The contact surface of the second upper wheel 32A that contacts the support surface 116C is positioned above the lower end of the gear housing 4.

[0162] The second lower wheel 32B rolls in the front-rear direction inside the second lower groove 116B. The second lower groove 116B has a support surface 116D (second lower support surface) that supports the second lower wheel 32B. The support surface 116D faces upward. The lower end of the second lower wheel 32B contacts the support surface 116D. The contact surface of the second lower wheel 32B that contacts the support surface 116D is positioned above the lower end of the gear housing 4.

[0163] Like the spikes 104 described in the first embodiment above, the amount by which each of the four spikes 114 protrudes downward from the base plate 111 can be individually adjusted. By adjusting the amount by which the spikes 114 protrude, the height and inclination angle of the support surfaces (115A, 115B, 116A, 116D) are adjusted.

[0164] A rear handle 27 is fixed to the gear housing 4. At least a portion of the rear handle 27 protrudes rearward from the gear housing 4. The rear handle 27 is fixed to the gear housing 4 by screws. The screws for fixing the rear handle 27 to the gear housing 4 are inserted into the screw holes 18.

[0165] <How to use> Next, a method of using the electric excavator 1B according to this embodiment will be described. Figure 26 is a side view for explaining a method of using the electric excavator 1B according to this embodiment.

[0166] The electric excavator 1B is used to form a horizontal hole in an excavation target. The electric excavator 1B is used with the motor housing 2 disposed above the gear housing 4. That is, the electric excavator 1B is used in a vertically placed state.

[0167] The guide device 110 is placed on the ground at the work site so that the spikes 104 are stuck into the ground at the work site. The electric excavator 1B is placed on the guide device 110. The first wheel 31 contacts the support surfaces (115C, 115D) and the second wheel 32 contacts the support surfaces (116C, 116D), so that the electric excavator 1A is placed vertically.

[0168] The operator holds the electric excavator 1B so that the motor housing 2 is located above the gear housing 4. In the example shown in Fig. 26, the operator holds the first handle portion 3B with his right hand and holds the rear handle 27 with his left hand.

[0169] The operator pulls the trigger lever 11A with the fingers of his / her right hand gripping the first handle portion 3B. By pulling the trigger lever 11A, the rotation output part 5 rotates with the drill bit 19 attached thereto.

[0170] The operator moves the electric excavator 1B forward relative to the guide device 110 so that the front end portion 19U of the rotating drill bit 19 is pressed against the excavation target present in front of the electric excavator 1B. The first wheel 31 rolls on the support surfaces (115C, 115D) and the second wheel 32 rolls on the support surfaces (116C, 116D), thereby allowing the electric excavator 1B to move forward.

[0171] The rotating drill bit 19 is pressed against the target to be excavated, thereby excavating the target and forming a lateral hole in the target. With the drill bit 19 rotating, the electric drilling machine 1B is pushed forward by the operator, thereby progressing the formation of the lateral hole.

[0172] In order to discharge the excavated material from the horizontal hole formed in the excavation target, the operator moves the electric excavator 1B backward relative to the guide device 110 at any timing so that the drill bit 19 is pulled out of the excavation target. The first wheel 31 rolls on the support surfaces (15C, 15D) and the second wheel 32 rolls on the support surfaces (16C, 16D), thereby allowing the electric excavator 1B to move backward.

[0173] As the electric drilling machine 1B is moved backward, the drill bit 19 is pulled out of the drilling target, and the drilled material is discharged from the horizontal hole formed in the drilling target.

[0174] <Effects> As described above, in this embodiment, the contact surface of the first wheel 31 that contacts the support surfaces (115C, 115D) and the contact surface of the second wheel 32 that contacts the support surfaces (116C, 116D) may each be positioned above the lower end of the gear housing 4.

[0175] In the above configuration, the electric excavator 1B can move in the front-rear direction while being suspended between the left support surface (115C, 115D) and the right support surface (116C, 116D).

[0176] In this embodiment, the first wheel 31 may include a first upper wheel 31A and a first lower wheel 31B disposed below the first upper wheel 31 A. The second wheel 32 may include a second upper wheel 32A and a second lower wheel 32B disposed below the second upper wheel 32A.

[0177] In the above configuration, the electric excavator 1B can move smoothly in the front-rear direction. The pitch motion of the electric excavator 1B is suppressed by the first upper wheel 31A and the first lower wheel 31B and the second upper wheel 32A and the second upper wheel 32A. The pitch motion refers to the motion of the electric excavator 1B swinging about a pitch axis extending in the left-right direction. When the electric excavator 1B is advanced so that the drill bit 19 is pressed against an excavation target present in front of the electric excavator 1B, the pitch motion is suppressed, so that the electric excavator 1B can advance straight, and therefore, an appropriate horizontal hole can be formed in the excavation target with good workability.

[0178] In this embodiment, at least one of the first upper wheels 31A and the first lower wheels 31B may be provided in a plurality of numbers in the front-rear direction. At least one of the second upper wheels 32A and the second lower wheels 32B may be provided in a plurality of numbers in the front-rear direction.

[0179] With the above configuration, the electric excavator 1B can move smoothly in the front-rear direction.

[0180] In this embodiment, one first upper wheel 31A may be disposed, and two first lower wheels 31B may be disposed in the front-rear direction. One second upper wheel 32A may be disposed, and two second lower wheels 32B may be disposed in the front-rear direction. The motor rotation axis MX of the motor 8 may extend in the up-down direction. The rotation axis AX5 of the rear first lower wheel 31B and the rotation axis AX6 of the rear second lower wheel 32B may be disposed rearward of the motor rotation axis MX of the motor 8, and the rotation axis AX5 of the front first lower wheel 31B and the rotation axis AX6 of the front second lower wheel 32B may be disposed forward of the motor rotation axis MX of the motor 8. In the front-rear direction, the first upper wheel 31A may be disposed between the two first lower wheels 31B. In the front-rear direction, the second upper wheel 32A may be disposed between the two second lower wheels 32B.

[0181] With the above configuration, the electric excavator 1B can move smoothly in the front-rear direction.

[0182] [Third embodiment] A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0183] <Electric excavator> FIG. 27 is a perspective view of the electric excavator 1C according to this embodiment, seen from the front. FIG. 28 is a perspective view of the electric excavator 1C according to this embodiment, seen from the rear. FIG. 29 is a top view of the electric excavator 1C according to this embodiment. FIG. 30 is a bottom view of the electric excavator 1C according to this embodiment. FIG. 31 is an exploded perspective view of the electric excavator 1C according to this embodiment. FIG. 32 is a vertical sectional view of the electric excavator 1C according to this embodiment. FIG. 33 is a horizontal sectional view of the electric excavator 1C according to this embodiment.

[0184] In this embodiment, a drill assembly is attached to the main body 6. The drill assembly includes an adaptor 500 attached to the rotary output section 5, a drill bit 19 supported by the adaptor 500 so as to be movable in the front-rear direction, a support member 120 that rotatably supports the drill bit 19, and a handle 122 connected to the support member 120 via a rod member 123 and a rod member 124.

[0185] The adapter 500 is a rod-shaped member that is long in the front-rear direction. The length of the adapter 500 in the front-rear direction may be longer than the length of the drilling shaft 19A of the drill bit 19 in the front-rear direction, or may be substantially the same as the length of the drilling shaft 19A in the front-rear direction. The rear end of the adapter 500 is inserted into the insertion hole 52A of the drill chuck 52. The rear end of the adapter 500 is fixed to the drill chuck 52.

[0186] An insertion hole 19E into which the adapter 500 is inserted is provided inside the drilling shaft 19A. The insertion hole 19E of the drilling shaft 19A is long in the front-rear direction. The adapter 500 can move relative to the drilling shaft 19A in the front-rear direction along the insertion hole 19E of the drilling shaft 19A.

[0187] The adapter 500 has a long hole 501 that is long in the front-rear direction. A support hole 19F is provided at the rear end of the drilling shaft 19A. The fixing tool 5B is inserted into the long hole 501 through the support hole 19F. The inner diameter of the support hole 19F is substantially equal to the outer diameter of the fixing tool 5B. The inner diameter of the support hole 19F may be slightly larger than the outer diameter of the fixing tool 5B. By inserting the fixing tool 5B into the support hole 19F and the long hole 501, the relative rotation between the adapter 500 and the drill bit 19 is suppressed. When the rotation output part 5 rotates and the adapter 500 rotates, the drill bit 19 rotates together with the adapter 500. The fixing tool 5B can move in the front-rear direction along the long hole 501. When the drill bit 19 moves in the front-rear direction relative to the adapter 500, the fixing tool 5B supported by the support hole 19F moves in the front-rear direction together with the drill bit 19.

[0188] The support member 120 rotatably supports the drill bit 19. The support member 120 is provided with a recess 120A in which the rear part of the drill bit 19 is disposed. The drill bit 19 is rotatably supported on the inner surface of the recess 120A.

[0189] A flange portion 19G is provided at the rear portion of the drill bit 19. The support member 120 has a front portion in contact with the front surface of the flange portion 19G, a rear portion in contact with the rear surface of the flange portion 19G, and a connecting portion connecting the front portion and the rear portion.

[0190] The support member 120 is movable in the front-rear direction. When the support member 120 moves forward, the drill bit 19 moves forward. When the support member 120 moves rearward, the drill bit 19 moves rearward. When the rear portion of the support member 120 comes into contact with the rear surface of the flange portion 19G, the drill bit 19 moves forward as the support member 120 moves forward. When the front portion of the support member 120 comes into contact with the front surface of the flange portion 19G, the drill bit 19 moves rearward as the support member 120 moves rearward.

[0191] The handle 122 is disposed rearward of the gear housing 4. An operator can move the handle 122 in the front-rear direction.

[0192] When the handle 122 is moved forward by the operator, the support member 120 connected to the handle 122 via the rod members 123 and 124 moves forward together with the handle 122. When the support member 120 moves forward, the drill bit 19 moves forward relative to the adapter 500.

[0193] When the handle 122 is moved rearward by the operator, the support member 120 connected to the handle 122 via the rod members 123 and 124 moves rearward together with the handle 122. When the support member 120 moves rearward, the drill bit 19 moves rearward relative to the adapter 500.

[0194] The rod member 123 is disposed to the left of the gear housing 4 and extends in the front-rear direction. The rod member 124 is disposed to the right of the gear housing 4 and extends in the front-rear direction. The rod members 123 and 124 each connect the support member 120 to the handle 122. The rod members 123 and 124 are each supported by the gear housing 4 so as to be slidable in the front-rear direction.

[0195] In this embodiment, a joint member 125 is fixed to the left part of the gear housing 4. The joint member 125 is fixed to the left part of the gear housing 4 by a screw. The joint member 125 is fixed to the gear housing 4 by a screw inserted into a screw hole 18 provided in the left part of the gear housing 4. The screw for fixing the joint member 125 to the gear housing 4 also fixes the left part of the rear handle 27 to the gear housing 4. That is, the joint member 125 and the left part of the rear handle 27 are fastened together to the gear housing 4 by a screw inserted into the screw hole 18 in the left part of the gear housing 4. A guide part having a guide hole 127 is fixed to the upper part of the joint member 125. The guide part having the guide hole 127 is also fixed to the gear housing 4 by a screw inserted into a screw hole 16 provided in the left part of the gear housing 4. The rod member 123 is inserted into the guide hole 127. The rod member 123 is guided in the front-rear direction by the guide hole 127. The rod member 123 is supported by the gear housing 4 via a guide portion having a guide hole 127 so as to be movable in the front-rear direction.

[0196] In this embodiment, a joint member 126 is fixed to the right part of the gear housing 4. The joint member 126 is fixed to the right part of the gear housing 4 by a screw. The joint member 126 is fixed to the gear housing 4 by a screw inserted into a screw hole 18 provided in the right part of the gear housing 4. The screw for fixing the joint member 126 to the gear housing 4 also fixes the right part of the rear handle 27 to the gear housing 4. That is, the joint member 126 and the right part of the rear handle 27 are fastened together to the gear housing 4 by a screw inserted into the screw hole 18 in the right part of the gear housing 4. A guide part having a guide hole 128 is fixed to the upper part of the joint member 126. The guide part having the guide hole 128 is also fixed to the gear housing 4 by a screw inserted into the screw hole 16 provided in the right part of the gear housing 4. The rod member 124 is inserted into the guide hole 128. The rod member 124 is guided in the front-rear direction by the guide hole 128. The rod member 124 is supported by the gear housing 4 via a guide portion having a guide hole 128 so as to be movable in the front-rear direction.

[0197] In this embodiment, a ground contact member 121 is disposed below the gear housing 4. The ground contact member 121 is in contact with the ground at a work site. A left portion of the ground contact member 121 is fixed to a joint member 125 by a screw 129. A right portion of the ground contact member 121 is fixed to a joint member 126 by a screw 130.

[0198] <How to use> Next, a method of using the electric excavator 1C according to this embodiment will be described. Figures 34 and 35 are each a side view for explaining a method of using the electric excavator 1C according to this embodiment.

[0199] The electric excavator 1C is used for forming a horizontal hole in an excavation target. The electric excavator 1C is used with the motor housing 2 disposed above the gear housing 4. That is, the electric excavator 1C is used in a vertically placed state.

[0200] The electric excavator 1C is placed so that the lower surface of the ground contact member 121 is in contact with the ground at a work site. By placing the ground contact member 121 in contact with the ground, the electric excavator 1C is placed in a vertical position.

[0201] The operator holds the electric excavator 1C so that the motor housing 2 is located above the gear housing 4. In the example shown in Figures 34 and 35, the operator grips the first handle portion 3B with his right hand and grips the handle 122 with his left hand.

[0202] The operator pulls the trigger lever 11A with the fingers of his / her right hand gripping the first handle portion 3B. By pulling the trigger lever 11A, the rotation output part 5 rotates with the drill bit 19 attached thereto.

[0203] 35, the operator moves the handle 122 forward with his left hand so that the front end 19U of the rotating drill bit 19 is pressed against the drilling target present in front of the electric drilling machine 1B. As the operator moves the handle 122 forward, the support member 120 connected to the handle 122 via the rod members 123 and 124 moves forward together with the handle 122. As the support member 120 moves forward, the drill bit 19 moves forward relative to the adapter 500.

[0204] The rotating drill bit 19 moves forward and is pressed against the target to be excavated, thereby excavating the target and forming a lateral hole in the target. With the drill bit 19 rotating, the electric drilling machine 1B is pushed forward by the operator, thereby progressing the formation of the lateral hole.

[0205] In order to discharge the drilled material from the horizontal hole formed in the drilling target, the operator pulls the handle 122 rearward at any timing so that the drill bit 19 is pulled out from the drilling target. When the operator moves the handle 122 rearward, the support member 120 connected to the handle 122 via the rod members 123 and 124 moves rearward together with the handle 122. When the support member 120 moves rearward, the drill bit 19 moves rearward relative to the adapter 500.

[0206] As the drill bit 19 is moved rearward, the drill bit 19 is pulled out of the drilling target, and the drilled material is discharged from the lateral hole formed in the drilling target.

[0207] <Effects> As described above, in this embodiment, the electric drilling machine 1C may include a motor 8, a motor housing 2 that accommodates the motor 8, a reduction gear mechanism 14, a gear housing 4 that is arranged lower than the motor housing 2 and accommodates the reduction gear mechanism 14, a rotation output section 5 that protrudes forward from the gear housing 4 and rotates based on the rotational force transmitted from the motor 8 via the reduction gear mechanism 14, an adapter 500 attached to the rotation output section 5, a drill bit 19 supported on the adapter 500 so as to be movable in the forward / backward direction, a support member 120 that rotatably supports the drill bit 19 and is movable in the forward / backward direction, and a handle 122 connected to the support member 120.

[0208] In the above configuration, an operator can move the drill bit 19 in the front-rear direction by moving the handle 122 in the front-rear direction. This allows a lateral hole to be formed in the drilling target with good workability.

[0209] In this embodiment, the handle 122 may be supported by the gear housing 4 so as to be movable in the front-rear direction.

[0210] In the above configuration, the handle 122 can move smoothly in the front-rear direction while being supported by the gear housing 4.

[0211] In this embodiment, the drill assembly may include an adapter 500 attached to a rotary output section 5 that protrudes forward from a gear housing 4 of the electric drilling machine 1A and rotates around a rotation axis extending in the fore-and-aft direction, a drill bit 19 supported on the adapter 500 so as to be movable in the fore-and-aft direction, a support member 120 that rotatably supports the drill bit 19 and is movable in the fore-and-aft direction, and a handle 122 that is positioned rearward of the gear housing 4 and connected to the support member 120.

[0212] In the above configuration, an operator can move the drill bit 19 in the front-rear direction by moving the handle 122 in the front-rear direction. This allows a lateral hole to be formed in the drilling target with good workability.

[0213] In this embodiment, the drill assembly may include a rod member 123 and a rod member 124 that connect the support member 120 and the handle 122 and are slidably supported in the gear housing 4.

[0214] In the above configuration, the rod members 123 and 124 are slidably supported by the gear housing 4, allowing the handle 122 to move smoothly in the front-rear direction.

[0215] [Other embodiments] In the first embodiment described above, each of the first wheel 21, the second wheel 22, and the third wheel 23 rolls on the support surface 101A, which is a flat surface. The first support surface on which the first wheel 21 rolls, the second support surface on which the second wheel 22 rolls, and the third support surface on which the third wheel 23 rolls may be separate support surfaces.

[0216] In the above-described first embodiment, the electric excavator 1A travels in the front-rear direction on the support surface 101A of the guide device 100. The electric excavator 1A may travel on the ground. That is, each of the first wheel 21, the second wheel 22, and the third wheel 23 may roll on the ground. Similarly, the electric excavator 1B according to the above-described twenty-second embodiment may travel on the ground.

[0217] In the above-described first embodiment, the first wheel 21 and the second wheel 22 may not rotate. In other words, the electric excavator 1A only needs to be provided with a first contact member and a second contact member that move while contacting a support surface. The same applies to the first wheel 31 and the second wheel 32 according to the above-described second embodiment.

[0218] In the above-described embodiment, the motor rotation axis MX indicating the rotation axis of the motor 8 and the output rotation axis DX indicating the rotation axis of the rotation output unit 5 are perpendicular to each other. The motor rotation axis MX indicating the rotation axis of the motor 8 and the output rotation axis DX indicating the rotation axis of the rotation output unit 5 may be parallel to each other. For example, the rotation output unit 5 does not have to protrude forward from the gear housing 4.

[0219] In the above embodiment, the power supply unit is the battery mounting unit 7 to which the battery pack 17 is attached. The power supply unit may be a cord connected to a commercial power source. [Explanation of symbols]

[0220] 1A...electric excavator, 1B...electric excavator, 1C...electric excavator, 2...motor housing, 2E...exhaust port, 3...handle housing, 3A...under section, 3B...first handle section, 3C...second handle section, 3D...battery holding housing section, 3F...intake port, 4...gear housing, 4A...cover, 5...rotation output section, 5A...adapter, 5B...fixing device, 6...main body, 7...battery mounting section, 8...motor, 9...forward / reverse switching lever, 10...main switch, 11...trigger switch, 11A...trigger lever, 11B...switch circuit, 13...controller, 14...reduction mechanism, 15...speed Switching lever, 16...screw hole, 17...battery pack, 18...screw hole, 19...drill bit, 19A...drilling shaft, 19B...drilling double helix blade, 19C...tip bit, 19D...cutting blade, 19E...insertion hole, 19F...support hole, 19G...flange portion, 19U...front end portion, 21...first wheel, 22...second wheel, 23...third wheel, 24...first axle, 25...second axle, 26...arm member, 27...rear handle, 31...first wheel, 31A...first upper wheel, 31B...first lower wheel, 32...second wheel, 32A...second upper wheel, 32B...second lower wheel, 34...first support member, 35...second support member , 36...first screw, 37...second screw, 51...spindle, 52...drill chuck, 52A...insertion hole, 53...needle bearing, 54...ball bearing, 55...bevel gear, 79...sensor circuit board, 80...rotor shaft, 81...stator, 82...rotor, 83...bearing, 84...bearing, 85...centrifugal fan, 100...guide device, 101...base plate, 101A...support surface, 102...left wall, 103...right wall, 104...spike, 110...guide device, 111...base plate, 112...left wall, 113...right wall, 114...spike, 115...first groove, 115A...first upper groove, 115B...first lower groove, 115C...support surface (first upper support surface), 115D...support surface (first lower support surface), 116...second groove, 116A...second upper groove, 116B...second lower groove, 116C...support surface (second upper support surface), 116D...support surface (second lower support surface), 120...support member, 120A...recess, 121...ground member, 122...handle, 123...rod member, 124...rod member, 125...joint member, 126...joint member, 127...guide hole, 128...guide hole, 129...screw, 130...screw, 140...pinion gear, 141...first planetary gear mechanism,142... second planetary gear mechanism, 143... intermediate shaft, 144... output shaft, 145... bearing, 146... bevel gear, 500... adapter, 501... long hole, AX1... rotating shaft, AX2... rotating shaft, AX3... rotating shaft, AX5... rotating shaft, AX6... rotating shaft, DX... output rotating shaft, MX... motor rotating shaft.

Claims

1. A motor; a motor housing that accommodates the motor; A reduction mechanism; a gear housing disposed below the motor housing and accommodating the reduction mechanism; a rotation output portion that protrudes forward from the gear housing and rotates based on the rotational force transmitted from the motor via the reduction mechanism with a drill bit attached thereto; a first contact member disposed to the left of the gear housing and in contact with a first support surface; a second contact member disposed to the right of the gear housing and in contact with the second support surface, Electric excavator.

2. The first contact member and the second contact member are each supported by the gear housing. The electric excavator according to claim 1 .

3. the first contact member includes a first wheel rotatably supported by the gear housing; The second contact member includes a second wheel rotatably supported on the gear housing. The electric excavator according to claim 1 .

4. a contact surface of the first wheel that contacts the first support surface and a contact surface of the second wheel that contacts the second support surface are each located below a lower end of the gear housing; The electric excavator according to claim 3.

5. a third wheel disposed forward of the first wheel and the second wheel and in contact with a third support surface; The electric excavator according to claim 3.

6. The third wheel is disposed between the first wheel and the second wheel in the left-right direction.

6. The electric excavator according to claim 5.

7. the drill bit includes a drilling shaft attached to the rotary output and a helical blade disposed around the drilling shaft; The third wheel is disposed below the drilling shaft and behind the helical blade.

6. The electric excavator according to claim 5.

8. The third wheel is supported on the gear housing via an arm member.

6. The electric excavator according to claim 5.

9. a contact surface of the first wheel that contacts the first support surface and a contact surface of the second wheel that contacts the second support surface are each positioned above a lower end of the gear housing; The electric excavator according to claim 3.

10. The first wheel includes a first upper wheel and a first lower wheel disposed below the first upper wheel, The second wheels include a second upper wheel and a second lower wheel disposed below the second upper wheel. The electric excavator according to claim 9.

11. At least one of the first upper wheel and the first lower wheel is provided in plurality in the front-rear direction, At least one of the second upper wheel and the second lower wheel is provided in plurality in the front-rear direction. The electric excavator according to claim 10.

12. One first upper wheel is disposed, and two first lower wheels are disposed in the front-rear direction, One second upper wheel is disposed, and two second lower wheels are disposed in the front-rear direction, The rotation shaft of the motor extends in the vertical direction, a rotation shaft of the first lower wheel on the rear side and a rotation shaft of the second lower wheel on the rear side are each disposed rearward of a rotation shaft of the motor, a rotation shaft of the first lower wheel on the front side and a rotation shaft of the second lower wheel on the front side are each disposed forward of a rotation shaft of the motor, the first upper wheel is disposed between two of the first lower wheels in the front-rear direction; In the front-rear direction, the second upper wheel is disposed between two of the second lower wheels. The electric excavator according to claim 11.

13. A motor; a motor housing that accommodates the motor; A reduction mechanism; a gear housing disposed below the motor housing and accommodating the reduction mechanism; a rotation output portion that protrudes forward from the gear housing and rotates based on the rotational force transmitted from the motor via the reduction mechanism with a drill bit attached thereto; an electric excavator having a contact member; a guide device having a support surface with which the contact member comes into contact and guiding the electric excavator in a forward and backward direction, Drilling system.

14. The guide device has an adjustment mechanism for adjusting the height and inclination angle of the support surface.

14. The drilling system of claim 13.

15. the contact member includes a first wheel disposed to the left of the gear housing, a second wheel disposed to the right of the gear housing, and a third wheel disposed in front of the gear housing, the support surface is a flat surface located below a lower end of the gear housing, each of the first wheel, the second wheel, and the third wheel contacts the support surface; 14. The drilling system of claim 13.

16. the contact member includes a first upper wheel disposed to the left of the gear housing and a first lower wheel disposed below the first upper wheel, a second upper wheel disposed to the right of the gear housing and a second lower wheel disposed below the second upper wheel, the support surfaces include a first upper support surface with which the first upper wheel comes into contact, a first lower support surface with which the first lower wheel comes into contact, a second upper support surface with which the second upper wheel comes into contact, and a second lower support surface with which the second lower wheel comes into contact, Each of the first lower support surface and the second lower support surface is disposed above a lower end portion of the gear housing.

14. The drilling system of claim 13.

17. A motor; a motor housing that accommodates the motor; A reduction mechanism; a gear housing disposed below the motor housing and accommodating the reduction mechanism; a rotation output portion that protrudes forward from the gear housing and rotates based on a rotational force transmitted from the motor via the reduction mechanism; an adapter attached to the rotary output; a drill bit supported by the adapter so as to be movable in the forward and backward directions; a support member that rotatably supports the drill bit and is movable in a forward and backward direction; a handle coupled to the support member. Electric excavator.

18. The handle is supported by the gear housing so as to be movable in the front-rear direction.

18. The electric excavator according to claim 17.

19. an adapter attached to a rotary output part that protrudes forward from a gear housing of the electric excavator and rotates around a rotary shaft that extends in the front-rear direction; a drill bit supported by the adapter so as to be movable in the forward and backward directions; a support member that rotatably supports the drill bit and is movable in a forward and backward direction; a handle disposed rearward of the gear housing and connected to the support member, Drill assembly.

20. a rod member that connects the support member and the handle and is slidably supported by the gear housing; 20. The drill assembly of claim 19.

21. A motor; a motor housing that accommodates the motor; A reduction mechanism; a gear housing that accommodates the reduction mechanism; a rotation output unit that rotates based on the rotational force transmitted from the motor via the reduction mechanism in a state where a drill bit is attached; a first contact member disposed to the left of the gear housing and in contact with a first support surface; a second contact member disposed to the right of the gear housing and in contact with the second support surface, Electric excavator.

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