Accessory for rotary tool

Abstract

To provide an accessory for a rotary tool capable of driving a helical pile deeply.SOLUTION: An accessory 20 for a rotary tool 1, which holds a helical pile 60 on the rotary tool 1, has a mounting part 21 that is attached to an output shaft 15 of the rotary tool 1. The accessory 20 has a head holding part 22 that is provided at a lower part of the mounting part 21, holds a head 61 of the helical pile 60, and has an opening 22b on the lower side. The accessory 20 has a neck holding part 24 that is separate from the head holding part 22, covers the opening 22b of the head holding part 22, and has a slit 24c through which a neck 62 of the helical pile 60 is inserted.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a rotary tool accessory that is attached to an output shaft of a rotary tool such as an earth auger. [Background technology]

[0002] The rotary tool has an output shaft protruding from the tool body. The output shaft rotates by the power of, for example, a motor. A tool tip such as a drill bit can be attached to the output shaft by a lock pin, a chuck mechanism, or the like. An accessory can be attached to the output shaft instead of the tool tip. The accessory is provided with an attachment portion corresponding to the lock pin or the chuck mechanism.

[0003] As described in Patent Document 1, a rotary tool that can be used as an earth auger has an output shaft that protrudes downward from a tool body. A drill bit is attached to the output shaft. Conventionally, an accessory for an earth auger that can be attached to the output shaft instead of the drill bit has been provided. The accessory holds a helical pile used, for example, for setting up a vinyl greenhouse. The helical pile has, for example, a hook-shaped or ring-shaped head on which a pipe, wire, etc. can be hooked, a neck that extends downward from the head, and a helical part that is wound in a helical shape below the neck.

[0004] The head of the helical pile is held by an accessory attached to the output shaft, and the tip of the helical portion is driven into the ground, for example. By driving the output shaft in this state, the helical pile rotates around the axis of the output shaft. The tip of the helical portion advances downward toward the ground along the helical shape. This allows the helical pile to be driven into the ground. A pipe or wire supporting a vinyl greenhouse, for example, is inserted into the head of the driven helical pile.

[0005] A conventional accessory for an earth auger has a holding part that holds the head and neck of the helical pile. The head and neck of the helical pile are inserted laterally into the holding part. The accessory has a lever member that prevents the helical pile from falling off the holding part. The lever member is connected to the lower end of the holding part so as to be rotatable in the vertical direction. When the lever member is rotated downward, the head and neck of the helical pile are exposed when viewed from the side. This allows the head and neck to be inserted laterally into the holding part. The lever member prevents the head and neck from falling off when rotated upward. The lower region of the holding part is provided to be long in the vertical direction in order to rotate the lever member in the vertical direction. This increases the vertical length of the helical pile housed in the holding part, particularly the vertical length of the neck.

[0006] When driving a helical pile into the ground using a conventional accessory for an earth auger, the lower end of the holding part comes into contact with the ground before the neck part is driven in sufficiently. As a result, the neck part protrudes a relatively long length from the ground. To drive the helical pile deeper, it is necessary to drive it in manually. On the other hand, when pulling out a helical pile that has been driven deep, the lower part of the holding part interferes with the ground, making it impossible to insert the head and neck part into the holding part. As a result, it is necessary to pull out the pile manually to the specified length, or to prepare a separate accessory dedicated to pulling out that can be attached to the earth auger.

[0007] In addition, in conventional earth auger accessories, the lever member is rotatably connected to the holding part by a screw or the like. Therefore, repeated rotation of the lever member can cause the screw to loosen. Loose screws must be periodically retightened. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2020-196098 A Summary of the Invention [Problem to be solved by the invention]

[0009] Thus, there is a need for an accessory for a rotary tool that can drive a helical pile deeper. [Means for solving the problem]

[0010] According to one aspect of the present disclosure, a rotary tool accessory for holding a helical pile on a rotary tool has a mounting part that is mounted on an output shaft of the rotary tool. The rotary tool accessory has a head holding part that is provided on a lower part of the mounting part and holds a head of the helical pile and has an opening on a lower side. The rotary tool accessory has a neck holding part that is separate from the head holding part, covers the opening of the head holding part, and has a slit through which the neck of the helical pile is inserted.

[0011] Therefore, the head holding portion is moved downward relative to the head of the helical pile. As a result, the head is inserted through an opening provided below the head holding portion. The opening of the head holding portion is then covered by the neck holding portion. This prevents the head from slipping out of the accessory, and allows the neck to be inserted and held through the slit in the neck holding portion. This allows the head to be held with most of the neck protruding outside the head holding portion. This makes it possible to reduce the vertical length of the neck housed in the accessory. Thus, the helical pile can be driven deep into the ground, etc., until most of the neck is buried. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a left side view of a rotary tool equipped with an accessory according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded perspective view of the rotary tool and the accessory. [Diagram 3] FIG. [Figure 4] FIG. 13 is a front view of the accessory for holding the helical stake. [Diagram 5] FIG. 13 is a bottom view of the accessory holding the helical stake. [Figure 6] A front view of the accessory when the neck holder is in the closed position. [Figure 7] 13 is a perspective view of the accessory when the neck holder is in a closed position, seen from the second side. FIG. [Figure 8] This is a side view of the accessory when the neck holder is in the closed position, as seen from the second side. [Figure 9] A rear view of the accessory when the neck holder is in the closed position. [Figure 10] A bottom view of the accessory when the neck holder is in the closed position. [Figure 11] 11 is a perspective view of the accessory when the stopper is released, as viewed from the first side. FIG. [Figure 12] 13 is a perspective view of the accessory when the stopper is released, as viewed from the second side. FIG. [Figure 13] 13 is a bottom view of the accessory when the stopper is released. FIG. [Figure 14] 11 is a perspective view of the accessory when the protrusion comes into contact with the unlocking portion, as viewed from the first side surface side. FIG. [Figure 15] 13 is a perspective view of the accessory when the protrusion abuts against the unlocking portion, as viewed from the second side. FIG. [Figure 16] 13 is a bottom view of the accessory when the protrusion abuts against the unlocking portion. FIG. [Figure 17] 1 is a perspective view of the accessory when the neck holder is in the open position, as viewed from the first side. [Figure 18] A front view of the accessory when the neck holder is in the open position. [Figure 19] This is a side view of the accessory when the neck holder is in the open position, as seen from the second side. [Figure 20] This is a bottom view of the accessory when the neck holder is in the open position. [Figure 21] FIG. 13 is a front view of the accessory holding the second helical pile. [Figure 22] FIG. 13 is a bottom view of the accessory holding the second helical pile. [Figure 23] FIG. 13 is a perspective view of a holder for a second helical pile. [Figure 24] FIG. 11 is a perspective view of an accessory according to a second embodiment of the present disclosure. [Diagram 25] FIG. [Figure 26]FIG. 2 is a front view of the head holder and the helical pile. [Figure 27] FIG. 2 is a front view of the head holder and the helical pile. [Figure 28] FIG. 11 is a perspective view of an accessory according to a third embodiment of the present disclosure. [Figure 29] FIG. [Diagram 30] This is a perspective view of the accessory when the neck holder is in the open position. [Diagram 31] This is a perspective view of the accessory in the process of moving the neck holder up to the closed position. [Diagram 32] A top view of the accessory in the process of moving the neck holder up to the closed position. [Diagram 33] A top view of the accessory when the neck holder is in the closed position. [Diagram 34] A bottom view of the accessory when the neck holder is in the closed position. [Diagram 35] 13 is a side view of the accessory as seen from the second side. FIG. [Diagram 36] FIG. 13 is a perspective view of a second neck holder for a second helical pile. [Figure 37] FIG. 13 is a front view of the accessory holding the second helical pile. [Figure 38] FIG. 13 is a bottom view of the accessory holding the second helical pile. [Figure 39] FIG. 11 is a perspective view of an accessory according to a fourth embodiment of the present disclosure. [Diagram 40] FIG. [Diagram 41] A top view of the accessory when the neck holder is in the closed position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] According to another feature of the present disclosure, the neck holder is attached to the head holder so as to be movable between a closed position that covers the opening of the head holder and an open position that opens the opening. Thus, by moving the neck holder to the closed position, the screw pile can be held so as not to fall off. By moving the neck holder to the open position and moving the accessory upward relative to the screw pile, the screw pile can be removed from the accessory. The screw pile can be switched between a holding state and a removable state by a simple operation of moving the neck holder. This can reduce the operation time.

[0014] According to another feature of the present disclosure, the upper part of the neck holding part is rotatably connected to the head holding part, so that the lower part of the neck holding part moves up and down. Therefore, the center of rotation of the neck holding part can be arranged at a position that avoids the opening of the head holding part, for example, at the upper part of the head holding part. Therefore, the head holding part can be made compact in the vertical direction. Moreover, the neck holding part can be made compact. For example, the height of the lower end of the neck holding part can be set to be approximately the same height as the lower end of the head holding part when moved to the closed position. The neck holding part moves upward when in the open position, and moves downward when in the closed position. By making the head holding part and the neck holding part compact in the vertical direction, the lower end of the entire accessory can be placed at a high position when the neck holding part is moved to the closed position. Thus, the helical stake held by the accessory can be driven deep until the lower end of the accessory abuts against the ground or the like.

[0015] According to another feature of the present disclosure, the lower end of the neck holding part is located above the lower end of the head holding part when the neck holding part is in the open position. Therefore, with the neck holding part moved to the open position, the head holding part is moved from above to below toward the head of the helical pile. This allows the head to enter the opening of the head holding part and be held by the head holding part. This allows the helical pile to be driven deep until the lower end of the head holding part contacts the ground or the like. In addition, the head holding part can be attached to the head of the helical pile that has been driven deep. This allows the helical pile to be pulled out using an accessory attached to the output shaft of the rotary tool.

[0016] According to another feature of the present disclosure, the rotary tool accessory has a positioning mechanism for holding the neck holder in an open position. Therefore, when the head of the helical pile is inserted into the head holder, the neck holder can be held in the open position to keep the opening of the head holder open. This improves the workability of attaching the helical pile to the accessory. Also, when the helical pile is removed using the accessory, the neck holder can be held in the open position to keep the opening of the head holder open. This improves the workability of removing the helical pile.

[0017] According to another feature of the present disclosure, the positioning mechanism has a stopper movably provided on the head holding part. The positioning mechanism has a biasing member that biases the stopper. The positioning mechanism has an insertion part that is formed on the neck holding part and into which the base end of the stopper is inserted using the biasing force of the biasing member. Therefore, the stopper can be automatically moved toward the base end side by the biasing force of the biasing member. Therefore, the neck holding part can be easily held in the open position. Moreover, by inserting the base end of the stopper into the insertion part, the neck holding part can be maintained in the open position. Thus, it is possible to suppress inadvertent movement of the neck holding part when inserting the helical pile into the head holding part or when pulling out the helical pile using an accessory. This improves workability.

[0018] According to another feature of the present disclosure, the stopper has a rod-shaped pin. The stopper has a tip end of the pin that penetrates the neck holding portion. The stopper has a large diameter portion provided at the tip end. The stopper has an unlocking portion that protrudes from the large diameter portion toward a base end side of the pin. The unlocking portion abuts against an outer surface of the neck holding portion by moving the stopper against the biasing member and rotating it about its axis.

[0019] Therefore, by abutting the unlocking portion against the outer surface of the neck holding portion, the stopper can be prevented from moving toward the base end. This allows the neck holding portion to be maintained in an unlocked state and the neck holding portion to be moved. When locking the neck holding portion, the stopper is rotated around the axis, and the biasing force of the biasing member causes the unlocking portion to move toward the base end from the outer surface of the neck holding portion. This allows the neck holding portion to be maintained in the open position. Thus, the neck holding portion can be switched between locked and unlocked states with a simple, tool-less operation.

[0020] According to another feature of the present disclosure, the neck holder is connected to the head holder so as to be rotatable about a rotation axis. The neck holder is provided with a sliding hole that is arc-shaped about the rotation axis and through which the tip of the pin is inserted. Therefore, when the neck holder is in an unlocked state, the pin moves within the arc-shaped sliding hole when the neck holder is rotated about the rotation axis. Therefore, the neck holder can be rotated smoothly.

[0021] According to another feature of the present disclosure, a protrusion is provided on the outer surface of the neck holder, which pushes the unlocking portion into the sliding hole when the neck holder is rotated from the closed position to the open position. Therefore, with the unlocking portion in contact with the outer surface of the neck holder, the neck holder is rotated beyond a predetermined angle. This causes the protrusion to abut the unlocking portion. When the neck holder is further rotated, the protrusion pushes the unlocking portion into the sliding hole. This causes the stopper including the unlocking portion to move toward the base end side due to the biasing force of the biasing member, locking the neck holder. Thus, the unlocked state of the neck holder can be easily switched to the locked state simply by rotating the neck holder.

[0022] According to another feature of the present disclosure, the end of the unlocking part becomes thinner toward the base end. Therefore, the frictional force between the end of the unlocking part and the outer surface of the neck holding part can be suppressed. Therefore, when the end of the unlocking part abuts against the outer surface of the neck holding part, the neck holding part can be moved smoothly. Also, when the end of the unlocking part abuts against the outer surface of the neck holding part, the stopper can be smoothly rotated on its axis. This allows the stopper to be rotated on its axis to smoothly switch the neck holding part from the unlocked state to the locked state.

[0023] According to another feature of the present disclosure, the neck holder is formed with a first insertion portion as an insertion portion into which the stopper is inserted when the neck holder is in a closed position, and a second insertion portion as an insertion portion into which the stopper is inserted when the neck holder is in an open position.

[0024] Therefore, by inserting the stopper into the first insertion portion, the neck holding portion can be held in the closed position. This prevents the neck holding portion from inadvertently moving from the closed position. This allows the head and neck of the helical pile to be held more securely. Furthermore, by inserting the stopper into the second insertion portion, the neck holding portion can be held in the open position. This prevents the neck holding portion from inadvertently moving from the open position. This allows the opening of the head holding portion to be maintained in an open state. This improves workability when inserting the helical pile into the head holding portion and when pulling out the helical pile using an accessory.

[0025] According to another feature of the present disclosure, a head abutment portion against which the head of the helical pile abuts is provided inside the head holding portion. A removably attached holder is provided inside the head holding portion. The holder is provided with a second head abutment portion against which the head of the second helical pile abuts at a position below the head abutment portion. Thus, by providing a removable holder inside the head holding portion, multiple types of helical piles with different head shapes can be held by the accessory. Therefore, the accessory can be used to drive or pull out multiple types of helical piles.

[0026] According to another feature of the present disclosure, an accessory for a rotary tool for holding a helical pile on a rotary tool has a mounting part, a head holding part, and a neck holding part. The mounting part is mounted on an output shaft of the rotary tool. The head holding part is provided on a lower part of the mounting part and has a first holding surface and a lower opening. The first holding surface holds the head of the helical pile. The neck holding part has a second holding surface, a lower surface, and a slit. The second holding surface is separate from the head holding part and cooperates with the first holding surface to hold the head of the helical pile. The lower surface covers the opening of the head holding part. The neck of the helical pile is inserted into the slit.

[0027] Therefore, the head of the helical pile is placed on the neck holding part in the open position, with the neck of the helical pile inserted into the slit. The neck holding part is moved from the open position to the closed position together with the head of the helical pile. By this operation, the head is held between the first holding surface of the head holding part and the second holding surface of the neck holding part. The lower surface of the neck holding part prevents the head from falling off downward. Therefore, the head can be held while most of the neck protrudes outside the accessory. This makes it possible to reduce the vertical length of the neck housed in the accessory. Thus, the helical pile can be driven deep into the ground, etc., until most of the neck is buried.

[0028] According to another feature of the present disclosure, the neck holder is attached to the head holder so as to be slidable between a closed position and an open position. In the closed position, the underside of the neck holder covers the opening of the head holder. In the open position, the underside of the neck holder opens the opening. Thus, the neck holder performs a simple sliding action relative to the head holder. This allows the accessory to have a simple structure. This improves the ease of installation when assembling the accessory.

[0029] According to another aspect of the present disclosure, the rotary tool accessory includes a locking mechanism that holds the neck holder in a closed position. Therefore, the neck holder is securely held in the closed position by the locking mechanism. This allows the head of the helical pile to be stably held. This allows the driving operation of the helical pile to be stabilized.

[0030] According to another feature of the present disclosure, the locking mechanism has an engagement portion, a stopper, and a biasing member. The engagement portion is provided on the neck holding portion. The stopper is movably provided on the head holding portion. The biasing member biases the stopper in a direction to engage with the engagement portion. Thus, the stopper is biased by the biasing member to automatically engage with the engagement portion and maintain the engaged state. This allows the neck holding portion to be easily held in the closed position. This increases the efficiency of the work of attaching the helical stake to the accessory.

[0031] According to another feature of the present disclosure, the neck holding portion is connected to the head holding portion so as to be vertically movable. The stopper is connected to the head holding portion so as to be horizontally movable. Therefore, when driving the helical pile, the user drives the rotary tool while pressing the rotary tool downward. Therefore, the head holding portion and the neck holding portion are pressed against each other in the vertical direction in which the neck holding portion can move. Therefore, it is possible to suppress the neck holding portion from moving relative to the head holding portion when the rotary tool is driven. This allows the rotational drive to be efficiently transmitted to the helical pile. Also, by making the movement direction of the neck holding portion and the engagement direction of the stopper approximately perpendicular, the neck holding portion can be more reliably held in the closed position.

[0032] According to another feature of the present disclosure, the engagement portion of the neck holding portion has an inclined surface. The inclined surface inclines downward from the upper end. The stopper has an abutment surface that abuts against the inclined surface. When the inclined surface abuts against the abutment surface from below, the stopper moves against the biasing force of the biasing member. Therefore, simply by moving the neck holding portion upward, the stopper automatically retreats from the engagement portion against the biasing force of the biasing member. When the neck holding portion is moved upward to the closed position, the stopper automatically engages with the engagement portion due to the biasing force of the biasing member. Therefore, the neck holding portion can be easily held by the stopper without falling downward.

[0033] According to another feature of the present disclosure, the stopper has an attachment portion, an arm, and a hook portion. The attachment portion is rotatably connected to the head holding portion. The arm extends from the attachment portion. The hook portion projects from a tip of the arm and is hooked onto the engagement portion. This allows the torque applied to the hook portion by the biasing force to be increased. This makes it possible to provide a stopper that reliably engages with the engagement portion while suppressing an increase in size of the biasing member.

[0034] According to another feature of the present disclosure, the head holding part has a rotation prevention part. The rotation prevention part restricts the rotation of the stopper when the engagement part is disengaged from the stopper. Therefore, by restricting the rotation of the stopper in the biasing direction, it becomes easier to retract the stopper from the engagement part in the direction opposite to the biasing direction when the neck holding part is moved upward. This improves the operability of moving the neck holding part upward and holding it in the closed position.

[0035] According to another feature of the present disclosure, the stopper has a second arm. The second arm extends from the mounting portion in a direction opposite to the arm. A biasing member for biasing the stopper is provided between the second arm and the head holding portion. Therefore, by lengthening the second arm, the biasing force of the biasing member can be made smaller. Therefore, the stopper can be rotated in the biasing direction while the biasing member is made smaller in size.

[0036] According to another feature of the present disclosure, the head holding portion is cylindrical and has a back surface and a pair of side surfaces. The back surface is located behind the second holding surface. The pair of side surfaces connect the back surface and the first holding surface. The back surface is provided with a rail extending in the vertical direction. The second holding surface has a guide. The guide is inserted into the rail so as to be movable in the vertical direction. Therefore, the neck holding portion can be smoothly guided in the vertical direction along the rail within the cylindrical head holding portion. In addition, the neck holding portion can be slid in the vertical direction with a simple structure. This improves the ease of assembly when attaching accessories.

[0037] According to another feature of the present disclosure, the neck holding part is detachably provided on the head holding part. A second neck holding part is attached to the head holding part in place of the neck holding part. The second neck holding part is structured so that the head of the second helical pile, which is smaller than the neck holding part, comes into contact with the second neck holding part. Therefore, the second neck holding part corresponding to the second helical pile having a different head shape can be easily assembled in place of the neck holding part. Therefore, it is possible to drive in a plurality of types of helical piles using accessories.

[0038] Next, a first embodiment of the present disclosure will be described with reference to Figs. 1 to 23. As an example of a rotary tool 1, an earth auger with a drill bit attached to an output shaft 15 extending downward is illustrated. In this disclosure, an accessory 20 for rotary tools is attached to the output shaft 15 in place of a drill bit. In the following description, the up / down, front / rear, left / right directions are defined based on the attitude of the rotary tool 1. The front / rear / left / right directions of the accessory 20 change as it rotates around an axis during use, so in the description, they are defined based on the attitude shown in Fig. 1.

[0039] As shown in FIG. 1, the rotary tool 1 has a motor housing 10 that houses a motor 11 in the center of a tool body 2. The motor 11 is an inner rotor type DC brushless motor. The motor 11 is provided with a motor shaft extending in the front-rear direction. The rotary tool 1 has a handle housing 3 behind the motor housing 10. The rotary tool 1 has a gear housing 12 in front of the motor housing 10. The tool body 2 extends long in the front-rear direction. An output shaft 15 protrudes downward from the front lower end of the gear housing.

[0040] As shown in Figures 1 and 2, the handle housing 3 has a loop shape that is long in the front-rear direction. A grip portion 3a extending in the front-rear direction is provided at the upper part of the handle housing 3. A user can hold the grip portion 3a with his / her hand. A controller accommodating portion 3c extending in the front-rear direction is provided at the lower part of the handle housing 3. A controller 7 that outputs a control signal for the rotating tool 1 is accommodated in the controller accommodating portion 3c. The controller 7 is provided in a shallow rectangular box-shaped case with a circuit board accommodated therein. The controller 7 is accommodated in the controller accommodating portion 3c with the shallow bottom facing up-down.

[0041] As shown in Figs. 1 and 2, the rear end of the grip portion 3a and the rear end of the controller storage portion 3c are connected in the vertical direction. The handle housing 3 has a battery mounting portion 3b on the rear surface of the connecting portion extending in the vertical direction. The battery 8 is removably mounted in the battery mounting portion 3b. The battery 8 can be mounted in the battery mounting portion 3b by sliding it from bottom to top. The battery 8 can be removed from the battery mounting portion 3b by sliding it from top to bottom in the opposite direction to the mounting direction. The motor 11 is driven by the power supply from the battery 8. The battery 8 is, for example, a lithium-ion battery with an output voltage of 40V. The battery 8 can be removed from the battery mounting portion 3b and repeatedly charged using a separately prepared charger. The battery 8 can be used as a power source for other electric work machines such as a screwdriver or an electric drill.

[0042] As shown in Figs. 1 and 2, the handle housing 3 has a main switch 4 in front of the grip portion 3a. When the main switch 4 is pressed to an ON state, power is supplied from the battery 8 to the controller 7, and the rotary tool 1 is started. Pressing the main switch 4 switches between starting and stopping the rotary tool 1. The handle housing 3 has a trigger 5 that can be pulled by a user holding the grip portion 3a with a finger or the like. The trigger 5 is provided on the inner circumference of the loop shape of the handle housing 3, on the front lower surface of the grip portion 3a. A trigger switch 5a that is turned ON when the trigger 5 is pulled is provided inside the handle housing 3. When the rotary tool 1 is started, the trigger 5 is pulled upward. This starts the motor 11 by supplying power from the battery 8. When the pulling operation of the trigger 5 is stopped, the trigger switch 5a is turned OFF and the motor 11 is stopped.

[0043] As shown in Fig. 1, the motor housing 10 has a forward / reverse switching lever 6 in front of the trigger 5. The forward / reverse switching lever 6 protrudes from the left and right sides of the motor housing 10 and can be moved left and right by pressing the protruding part. By moving the forward / reverse switching lever 6 left and right, the rotation direction of the motor 11 is switched between the forward direction and the reverse direction. As a result, the rotation direction of the output shaft 15 is switched between the forward direction and the reverse direction.

[0044] As shown in FIG. 1, the gear housing 12 accommodates the reduction mechanism 13. The reduction mechanism 13 includes a train of multiple gears. The reduction mechanism 13 reduces the output of the motor 11 and transmits it to the output shaft 15. The front part of the gear housing 12 accommodates the direction change mechanism 13a. The direction change mechanism 13a includes a driving bevel gear downstream of the reduction mechanism 13 and a driven bevel gear integral with the output shaft 15. The direction change mechanism 13a converts the output of the motor 11 around a shaft extending in the front-rear direction into a rotation around a shaft extending in the up-down direction of the output shaft 15 while reducing the speed. The lower part of the gear housing 12 is provided with a speed change lever 14. By rotating the speed change lever 14 back and forth, the rotation speed of the output shaft 15 can be switched between a first speed and a second speed higher than the first speed.

[0045] As shown in Figures 1 and 2, a front grip 17 extending in the left-right direction in a loop shape is provided above the gear housing 12. Both ends of the front grip 17 are connected to both the left and right sides of the gear housing 12. A reaction force receiving portion 18 and an auxiliary handle 19 are screwed to the gear housing 12 and the front grip 17, respectively. The reaction force receiving portion 18 extends leftward from the left side of the gear housing 12. The reaction force receiving portion 18 extends leftward forward of the output shaft 15 and the front end of the gear housing 12.

[0046] As shown in Figs. 1 and 2, the auxiliary handle 19 extends forward from the front ends of both the left and right sides of the gear housing 12. The front ends of the auxiliary handle 19 are connected in the left-right direction to form a loop. The user can support the rotary tool 1 by holding the grip portion 3a with one hand and holding the auxiliary handle 19 with the other hand. Furthermore, the reaction force receiving portion 18 is abutted against at least one of the left side of the body, for example, the left flank, the left hip, and the left thigh. A large reaction force may act on the tool body 2 via the drill bit or the helical pile 60 attached to the output shaft 15. By abutting the reaction force receiving portion 18 against the user's body, it is possible to suppress the rotation and wobbling of the tool body 2 caused by the reaction force.

[0047] As shown in Figures 1 and 2, the accessory 20 is connected to the output shaft 15 by a lock pin 16. The output shaft 15 is provided with a circular through hole 15a that penetrates perpendicular to the axial direction. A cylindrical mounting part 21 with the axial direction extending vertically is provided at the top of the accessory 20. The mounting part 21 is provided with an inner diameter that is the same as or slightly larger than the outer diameter of the output shaft 15. This allows the output shaft 15 to be inserted into the mounting part 21. The mounting part 21 is provided with a circular through hole 21a that penetrates perpendicular to the axial direction.

[0048] As shown in Fig. 2, the lock pin 16 has a cylindrical pin body 16a. The lock pin 16 has a head 16b provided at the base end of the pin body 16a and having a larger diameter than the pin body 16a. A wire 16c is connected to the head 16b. The wire 16c is provided with an annular engaging portion 16d. When the pin body 16a is inserted into the engaging portion 16d, the elasticity of the wire 16c causes the engaging portion 16d to clamp the pin body 16a.

[0049] The procedure for locking the mounting portion 21 to the output shaft 15 with the lock pin 16 will be described with reference to Figure 2. First, the output shaft 15 is inserted from the upper end of the mounting portion 21. The through hole 15a of the output shaft 15 and the through hole 21a of the mounting portion 21 are aligned in the same direction. The pin body 16a is inserted into both the through holes 15a and 21a. The head 16b is brought into contact with the outer peripheral surface of the mounting portion 21. The engagement portion 16d is engaged with the tip of the pin body 16a protruding from the through hole 21a. In this way, the mounting portion 21 is attached to the output shaft 15 so as to be rotatable integrally with the output shaft 15.

[0050] As shown in Figs. 1 to 3, the accessory 20 has a head holding part 22 that is integrally connected to the lower part of the mounting part 21. The accessory 20 has a neck holding part 24 that is separate from the head holding part 22 and is connected to the head holding part 22 so as to be rotatable in the vertical direction. The head holding part 22 and the neck holding part 24 cooperate to hold the helical pile 60. In the following description, a hook-shaped, annular, spiral, or other shaped part formed on the upper part of the helical pile 60 that can hook a pipe, wire, or the like is referred to as a head part 61. In the present disclosure, a substantially circular hook-shaped head part 61 is exemplified. A part of the lower part of the helical pile 60 that extends helically in the vertical direction is referred to as a helical part 63. A part that is narrower in width (front-to-back width in the drawings) than the head part 61 between the head part 61 and the helical part 63 in the vertical direction is referred to as a neck part 62.

[0051] As shown in Figs. 3 to 5, the head holding part 22 is a substantially rectangular box shape. A substantially rectangular opening 22b is provided at the lower end 22c of the head holding part 22. The head 61 of the helical pile 60 can be inserted into the opening 22b. The front-rear width of the opening 22b is substantially the same as or slightly larger than the front-rear width of the head 61. The left-right width of the opening 22b is substantially the same as or slightly larger than the left-right thickness of the head 61. The head holding part 22 has a front surface 22a that forms the left end of the opening 22b. The head holding part 22 has a back surface 23b that forms the right end of the opening 22b. The front surface 22a and the back surface 23b extend in a plane in the up-down direction and the front-rear direction. The front surface 22a and the back surface 23b are substantially parallel to each other. The head holding part 22 has a first side surface 22d that forms the front end of the opening 22b. The head holding part 22 has a second side surface 22f that forms the rear end of the opening 22b. The first side surface 22d and the second side surface 22f extend in a planar shape in the up-down and left-right directions. The first side surface 22d and the second side surface 22f are approximately parallel to each other. For the sake of convenience, in FIG. 4, a part of the front side (left side) is omitted.

[0052] As shown in Figs. 3 to 5 and 9, the head holding part 22 has a head abutment part 23 that abuts against the head 61 of the helical pile 60 when the head 61 is held. The head abutment part 23 includes an upper surface 23a that is integrally connected to the mounting part 21, and the above-mentioned back surface 23b. The upper surface 23a extends in a flat shape in the horizontal direction. The right end of the upper surface 23a is connected to the upper end of the back surface 23b. The head 61 is restricted from moving further upward relative to the head holding part 22 by abutting against the upper surface 23a. The thickness of the head 61 in the left-right direction is approximately the same as or slightly thinner than the left-right distance between the front surface 22a and the back surface 23b. Therefore, the head 61 is restricted from moving in the left-right direction relative to the head holding part 22 by entering between the front surface 22a and the back surface 23b. The head 61 is restricted from moving in the front-rear direction relative to the head holding part 22 by entering between the first side surface 22d and the second side surface 22f.

[0053] 3, 5, and 9, a bent portion 23d is provided at the left end of the upper surface 23a, which is bent downward in an L-shape relative to the upper surface 23a. The bent portion 23d extends downward in a flat shape from the upper surface 23a to a position above the upper end of the front surface 22a. A through hole 23c is provided in the rear surface 23b for attaching a holder 40 (described later) with a screw 42 (see FIG. 22).

[0054] As shown in Figs. 3 to 5 and 8, the accessory 20 has a rotating shaft 28 that supports the neck holding part 24 rotatably relative to the head holding part 22. The rotating shaft 28 includes a first rotating shaft that protrudes forward from a first side surface 22d of the upper part of the head holding part 22, and a second rotating shaft that protrudes rearward from a second side surface 22f of the upper part of the head holding part 22. The rotating shaft 28 is located to the right of the output axis K in the left-right direction. The rotating shaft 28 is connected to an upper part of the neck holding part 24. A lower part of the neck holding part 24 moves up and down around the axis of the rotating shaft 28.

[0055] 3 to 5, the neck holder 24 is provided in a generally rectangular box shape that opens upward and to the right. A planar front surface 24a is provided on the left side of the neck holder 24. When the neck holder 24 is in the closed position P1, the front surface 24a extends generally parallel to the front surface 22a of the head holder 22 and covers the front surface 22a from the left.

[0056] As shown in Figs. 3 to 6, a substantially flat lower surface 24b is provided at the lower end of the neck holding part 24. The lower surface 24b covers the opening 22b of the head holding part 22 from below when the neck holding part 24 is in the closed position P1. The lower surface 24b covers the opening 22b, thereby preventing the head 61 of the helical pile 60 from falling out of the opening 22b. It extends to the left of the front surface 22a of the head holding part 22 and substantially parallel to the front surface 22a. The lower surface 24b is provided with a slit 24c extending in the left-right direction. The opening 22b covered by the lower surface 24b is opened downward only at the portion of the slit 24c. The slit 24c is provided with a front-rear width that allows the neck 62 of the helical pile 60 to be inserted and restricts the entry of the head 61.

[0057] As shown in Figs. 3 to 6, a flat first side surface 24d is provided at the front of the neck holding part 24. The first side surface 24d extends in front of the first side surface 22d of the head holding part 22 and substantially parallel to the first side surface 22d. A circular through hole 24e is provided at the upper right side of the first side surface 24d, through which the rotary shaft 28 can be inserted. A slide hole 25 is provided at the upper left side of the first side surface 24d, penetrating the first side surface 24d in the front-rear direction. The slide hole 25 is provided in an arc shape centered on the through hole 24e. A stopper 31, which will be described later, is inserted into the slide hole 25. The neck holding part 24 has a protrusion 26 on an end face on the outer circumferential side (left side) of the slide hole 25. The protrusion 26 protrudes forward from the first side surface 24d. The protrusion 26 is provided as the same part as the first side surface 24d. The protrusion 26 has a flat first contact surface 26a on the upper end side. The protrusion 26 has a flat second contact surface 26b on the lower end side. The first contact surface 26a and the second contact surface 26b extend generally in the radial direction with the through hole 24e as the center.

[0058] As shown in Figs. 3 to 7, a flat second side surface 24f is provided at the rear of the neck holding part 24. The second side surface 24f extends substantially parallel to the second side surface 22f behind the second side surface 22f of the head holding part 22. A circular through hole 24g is provided at the upper right side of the second side surface 24f, through which the rotary shaft 28 can be inserted. Two circular through holes are provided at the upper left side of the second side surface 24f, which penetrate the first side surface 24d in the front-rear direction. These through holes are insertion parts 27 into which the base end 32a of the pin 32 described later can enter. The two insertion parts 27 are provided at positions at the same distance from the through hole 24g. That is, the two insertion parts 27 are arranged at a predetermined interval in the circumferential direction around the through hole 24g. When the neck holding part 24 is in the closed position P1, the insertion part 27 located at the top is the first insertion part 27a. When the neck holding part 24 is in the open position P2, the insertion part 27 located on the lower side is the second insertion part 27b.

[0059] As shown in Figs. 3 to 6, the accessory 20 has a positioning mechanism 30 that positions the neck holding part 24 relative to the head holding part 22. The positioning mechanism 30 has a stopper 31 that is movable in the front-rear direction relative to the head holding part 22 and the neck holding part 24. The stopper 31 is movable in the front-rear direction between a rear locked position and a front unlocked position. The stopper 31 has a rod-shaped pin 32 that extends in the front-rear direction. The pin 32 is provided in a cylindrical shape that extends linearly. Hereinafter, the rear end side of the pin 32 is referred to as the base end 32a, and the front end side is referred to as the tip end 32b. The base end 32a is inserted into the through hole 22g of the second side surface 22f of the head holding part 22. The base end 32a protrudes rearward from the through hole 22g and can enter the first insertion part 27a or the second insertion part 27b of the second side surface 24f of the neck holding part 24. The tip portion 32b is inserted through the through hole 22e in the first side surface 22d of the head holding portion 22 and the slide hole 25 in the first side surface 24d of the neck holding portion 24, and protrudes forward. The pin 32 is located to the left of the output axis K in the left-right direction.

[0060] As shown in FIGS. 3 to 5, the stopper 31 has a large diameter portion 33 at the tip portion 32b of the pin 32. The large diameter portion 33 is provided in a substantially cylindrical shape that is larger in the radial direction than the pin 32. The center of the large diameter portion 33 is located on the axial center of the pin 32. The positioning mechanism 30 has an unlocking portion 34 that holds the stopper 31 in the front unlocked position. The unlocking portion 34 is provided as a single part including the large diameter portion 33. The unlocking portion 34 extends from the large diameter portion 33 toward the tip side (rear) of the pin 32. Two unlocking portions 34 are provided at intervals of approximately 180° in the circumferential direction of the large diameter portion 33. One of the unlocking portions 34 is a first unlocking portion 34a that can abut against the first abutment surface 26a of the projection 26. One of the unlocking portions 34 is a second unlocking portion 34b that can abut against the second abutment surface 26b of the projection 26. The unlocking portion 34 has a substantially cylindrical end portion 34c at its rear end. The end portion 34c of the unlocking portion 34 becomes thinner as it extends rearward.

[0061] As shown in Figs. 4 and 5, the positioning mechanism 30 has a biasing member 35 that biases the stopper 31 rearward toward the base end 32a side. The biasing member 35 is, for example, a coil spring. The pin 32 is provided with a stepped portion 32c in which the diameter at the tip end 32b side is narrower than the diameter at the base end 32a side. The rear end of the biasing member 35 abuts against the stepped portion 32c. The front end of the biasing member 35 abuts against the inner surface (rear surface) of the first side surface 22d of the head holding part 22. The biasing member 35 biases the stopper 31 having the stepped portion 32c rearward relative to the head holding part 22.

[0062] The operation of the positioning mechanism 30 when the neck holding part 24 is opened upward will be described with reference to Figs. 7 to 20. First, as shown in Figs. 7 to 10, when the neck holding part 24 is located at the closed position P1, the opening 22b of the head holding part 22 is opened downward from the slit 24c of the neck holding part 24. The opening 22b is covered by the lower surface 24b of the neck holding part 24 in an area other than the slit 24c. The stopper 31 is biased backward by the biasing member 35. The base end 32a of the pin 32 is inserted into the first insertion part 27a. The two unlocking parts 34 are inserted into the sliding hole 25.

[0063] As shown in Figs. 11 to 13, the large diameter portion 33 of the stopper 31 is pulled forward against the biasing force. The stopper 31 is then rotated around the axis of the pin 32. The rotation direction of the stopper 31 is clockwise when viewed from the front. As a result, the two unlocking portions 34 come into contact with the outer surface (front surface) of the first side surface 24d of the neck holding portion 24. This restricts the rearward movement of the stopper 31. The base end portion 32a of the pin 32 comes out of the first insertion portion 27a of the neck holding portion 24 and moves forward. The base end portion 32a is supported within the through hole 22g provided in the second side surface 22f of the head holding portion 22. This allows the neck holding portion 24 to rotate upward around the rotation axis 28 relative to the head holding portion 22.

[0064] As shown in Figs. 14 to 16, the neck holder 24 is rotated upward relative to the head holder 22. When the neck holder 24 is rotated to a predetermined angle, the first unlock part 34a comes into contact with the first abutment surface 26a of the protrusion 26 provided on the first side surface 24d of the neck holder 24. When the neck holder 24 is further rotated, the first unlock part 34a is pressed against the first abutment surface 26a of the protrusion 26. The stopper 31 rotates counterclockwise when viewed from the front. The end 34c of the unlock part 34 becomes thinner toward the rear, so that it abuts against the first side surface 24d over a small area. Therefore, the force of rotating the neck holder 24 can be used to smoothly rotate the stopper 31. When the end 34c of the first unlock part 34a moves to the sliding hole 25, the end 34c of the second unlock part 34b also moves to the sliding hole 25. The two unlocking portions 34 move rearward within the slide hole 25 due to the biasing force of the biasing member 35. The stopper 31 moves rearward together with the unlocking portions 34.

[0065] As shown in Figs. 17 to 20, the neck holding part 24 is rotated upward to the open position P2. The base end 32a of the pin 32 enters the second insertion part 27b. As a result, the neck holding part 24 is restricted from rotating and held at the open position P2. At the timing immediately before that when the stopper 31 starts to move backward, the base end 32a of the pin 32 cannot yet enter the second insertion part 27b and abuts against the inner surface (front surface) of the second side surface 24f of the neck holding part 24. The base end 32a enters the second insertion part 27b with a slightly delayed timing. This makes it possible to prevent the base end 32a from failing to enter the second insertion part 27b. The base end 32a of the pin 32 enters and engages with the insertion part 27, so that the neck holding part 24 is held at a predetermined position relative to the head holding part 22. Therefore, there is no need to perform work such as screw tightening to maintain the position of the neck holding part 24. This can improve workability.

[0066] The operation of the positioning mechanism 30 when closing the neck holding part 24 downward will be described with reference to Figures 7 to 20. Since the operation is generally the same as that when opening the neck holding part 24 upward, only the different parts will be described in detail. The large diameter part 33 of the stopper 31 is pulled forward against the biasing force of the biasing member 35. The stopper 31 is then rotated counterclockwise as viewed from the front about the axis of the pin 32. The stopper 31 may also be rotated clockwise as viewed from the front. The two unlocking parts 34 abut against the outer surface of the first side surface 24d of the neck holding part 24. The base end part 32a of the pin 32 comes out of the second insertion part 27b of the neck holding part 24 and moves forward.

[0067] When the neck holding part 24 is rotated downward to a predetermined angle relative to the head holding part 22, the second unlocking part 34b comes into contact with the second abutment surface 26b of the protrusion 26. When the neck holding part 24 is further rotated, the second unlocking part 34b is pressed against the second abutment surface 26b of the protrusion 26. The stopper 31 rotates clockwise when viewed from the front. When the end 34c of the second unlocking part 34b moves to the sliding hole 25, the end 34c of the first unlocking part 34a also moves to the sliding hole 25. The two unlocking parts 34 move backward within the sliding hole 25 due to the biasing force of the biasing member 35. The stopper 31 moves backward together with the unlocking part 34. When the neck holding part 24 is rotated to the closed position P1, the base end 32a of the pin 32 enters the first insertion part 27a. As a result, the neck holder 24 is restricted from rotating and is held in the closed position P1.

[0068] As shown in Figures 19 and 20, when the neck holding part 24 is held in the open position P2, the opening 22b of the head holding part 22 is open downward without being covered by the neck holding part 24. Therefore, the accessory 20 can be lifted upward to pull out the head 61 (see Figure 1) of the helical pile 60 from inside the head holding part 22. The lower surface 24b of the neck holding part 24 moves to a height substantially the same as or higher than the lower end 22c of the head holding part 22. Therefore, when the lower end 22c of the head holding part 22 abuts against the ground or approaches the ground before the lower end of the neck holding part 24 hits the ground, interference between the lower end of the neck holding part 24 and the ground can be suppressed.

[0069] 8 and 19, the pin 32 of the positioning mechanism 30 and the rotation shaft 28, which is the center of rotation of the neck holding part 24, are arranged on either side of the output axis K. Therefore, whether the neck holding part 24 is held in the closed position P1 or in the open position P2, the center of gravity of the accessory 20 is located near the output axis K. This makes it possible to suppress wobbling when the accessory 20 is rotated around the output axis K. This makes it possible to suppress wobbling of the helical pile 60 (see FIG. 1) when driving and pulling out the helical pile 60.

[0070] With reference to FIG. 1, the operation of driving and extracting the helical pile 60 using the accessory 20 will be described. The lower end of the helical part 63 is brought into contact with the ground or the like. The accessory 20, which is integral with the output shaft 15, rotates the head 61 around the axis of the output axis K. This causes the helical part 63 to rotate around the output axis K, and the tip of the helical part 63 advances downward along the helical path through the ground. The helical pile 60 can be driven into the ground when the helical part 63 fits into the ground. The helical pile 60 can also be driven further downward so that the neck part 62 enters the ground. By holding the neck holding part 24 at the open position P2 (see FIG. 19), the helical pile 60 can be driven until the lower end 22c of the head holding part 22 abuts against the ground. The helical pile 60 is driven in with, for example, only the head part 61 exposed above the ground.

[0071] As shown in Fig. 1, the opening 22b of the head holding part 22 opens downward. Therefore, by holding the neck holding part 24 at the open position P2 (see Fig. 19) and lifting the accessory 20 upward together with the rotary tool 1, the head 61 can be pulled out from the head holding part 22. When pulling out the helical pile 60, the accessory 20 together with the rotary tool 1 is lowered downward so that the head 61 can be inserted into the opening 22b of the head holding part 22. By rotating the motor 11 in the opposite direction to that during the driving operation, the motor 11 can be driven to pull out the helical pile 60.

[0072] As shown in Figs. 21 and 22, a holder 40 provided separately can be attached inside the head holding portion 22. By attaching the holder 40, the accessory 20 can hold a head 66 of a second helical pile 65 having a shape different from the head 61 of the helical pile 60 (see Fig. 4). For example, the second helical pile 65 is provided by processing a rod material having a smaller diameter than the helical pile 60. For example, the head 66 of the second helical pile 65 has a shorter vertical length than the head 61 of the helical pile 60. For example, the head 66 has a shorter front-to-rear width than the head 61. For example, the head 66 has a thinner thickness in the left-to-right direction than the head 61. Note that, for convenience of explanation, the front side (left side) is partially omitted in Fig. 21.

[0073] As shown in Figs. 21 and 23, the holder 40 is provided by processing a plate-shaped member. The holder 40 has a second head abutment portion 41 that abuts against the head portion 66 of the second helical pile 65. The second head abutment portion 41 has a flat plate-shaped back surface 41c that extends in the up-down and front-rear directions. The second head abutment portion 41 has an upper surface 41a that is bent at a substantially right angle from the upper end of the back surface 41c toward the left. The second head abutment portion 41 has a pair of inclined surfaces 41b that are bent downward from both the front and rear ends of the upper surface 41a. The pair of inclined surfaces 41b are each bent at an angle of, for example, 45° with respect to the upper surface 41a. The upper surface 41a and the pair of inclined surfaces 41b cooperate to form a C-shaped receiving surface that is convex toward the top.

[0074] 22 and 23, two screw holes 41d penetrating laterally in the plate thickness direction are provided in the back surface 41c. Screws 42 inserted through holes 23c of head holding part 22 are fastened into the two screw holes 41d. Fastening the screws 42 enables holder 40 to be held inside head holding part 22.

[0075] As shown in Figs. 21 and 22, the upper surface 41a of the holder 40 is located below the upper surface 23a of the head holding part 22. Therefore, the head 66 can be prevented from wobbling in the vertical direction within the head holding part 22. The upper surface 41a and the pair of inclined surfaces 41b of the holder 40 are provided in a shape following the outer periphery of the head 66. Therefore, the head 66 can be prevented from wobbling in the front-rear direction within the head holding part 22. The thickness of the head 66 in the left-right direction is thinner than the left-right distance between the front surface 22a and the back surface 23b. Therefore, if the holder 40 is not attached to the head holding part 22, a left-right gap will be generated between the head 66 and the inside of the head holding part 22. The back surface 41c of the holder 40 is attached following the back surface 23b of the head holding part 22 so as to fill this gap. Therefore, the head 66 can be prevented from wobbling in the left-right direction within the head holding part 22. The neck 67 of the second helical pile 65 is inserted into the slit 24c of the neck holder 24 and extends downward. Therefore, the second helical pile 65 can be held by the accessory 20 in the same position as the helical pile 60 shown in FIG.

[0076] As described above, the accessory 20 for the rotary tool 1, which holds the helical pile 60 on the rotary tool 1, has a mounting part 21 that is mounted on the output shaft 15 of the rotary tool 1 as shown in Fig. 1. The accessory 20 has a head holding part 22 that is provided on the lower part of the mounting part 21, holds the head 61 of the helical pile 60, and has an opening 22b on the lower side. The accessory 20 has a neck holding part 24 that is separate from the head holding part 22, covers the opening 22b of the head holding part 22, and has a slit 24c through which the neck 62 of the helical pile 60 is inserted.

[0077] Therefore, the head holding part 22 is moved downward relative to the head 61 of the helical pile 60. As a result, the head 61 is inserted from the opening 22b provided below the head holding part 22. The neck holding part 24 then covers the opening 22b of the head holding part 22. This prevents the head 61 from slipping out of the accessory 20, and allows the neck 62 to be inserted and held through the slit 24c of the neck holding part 24. This allows the head 61 to be held with most of the neck 62 protruding outside the head holding part 22. This allows the vertical length of the neck 62 housed in the accessory 20 to be restricted. Thus, the helical pile 60 can be driven deep into the ground or the like until most of the neck 62 is buried.

[0078] As shown in Figures 1 and 2, the neck holding part 24 is attached to the head holding part 22 so as to be movable between a closed position P1 that covers the opening 22b of the head holding part 22 and an open position P2 (see Figure 17) that opens the opening 22b. Therefore, by moving the neck holding part 24 to the closed position P1, the helical pile 60 can be held so as not to fall off. By moving the neck holding part 24 to the open position P2 and moving the accessory 20 upward relative to the helical pile 60, the helical pile 60 can be removed from the accessory 20. Therefore, the helical pile 60 can be switched between a holding state and a removable state by a simple operation of moving the neck holding part 24. This can shorten the operation time.

[0079] As shown in Figs. 1, 2 and 17, the upper part of the neck holding part 24 is rotatably connected to the head holding part 22, and the lower part of the neck holding part 24 moves up and down. Therefore, the center of rotation of the neck holding part 24 can be arranged at a position that avoids the opening 22b of the head holding part 22, for example, at the upper part of the head holding part 22. Therefore, the head holding part 22 can be made compact in the vertical direction. Moreover, the neck holding part 24 can be made compact. For example, the height of the lower end (lower surface 24b) of the neck holding part 24 can be set to be approximately the same height as the lower end 22c of the head holding part 22 when moved to the closed position P1. The neck holding part 24 moves upward when in the open position P2, and moves downward when in the closed position P1. By making the head holding part 22 and the neck holding part 24 compact in the vertical direction, the lower end of the entire accessory 20 can be placed at a high position when the neck holding part 24 is moved to the closed position P1. In this way, the spiral pile 60 held by the accessory 20 can be driven deep into the ground until the lower end of the accessory 20 abuts against the ground or the like.

[0080] As shown in FIG. 19, the lower end (lower surface 24b) of the neck holding part 24 is located above the lower end 22c of the head holding part 22 when the neck holding part 24 is in the open position P2. Therefore, with the neck holding part 24 moved to the open position P2, the head holding part 22 is moved from above toward the head 61 (see FIG. 1) of the helical pile 60. This allows the head 61 to enter the opening 22b of the head holding part 22 and be held by the head holding part 22. Therefore, the helical pile 60 can be driven deep until the lower end 22c of the head holding part 22 abuts on the ground or the like. In addition, the head holding part 22 can be attached to the head 61 of the helical pile 60 that has been driven deep. This allows the helical pile 60 to be pulled out using the accessory 20 attached to the output shaft 15 (see FIG. 1) of the rotary tool 1.

[0081] As shown in Figures 17 to 20, the accessory 20 has a positioning mechanism 30 that holds the neck holding part 24 in the open position P2. Therefore, when inserting the head 61 (see Figure 1) of the helical pile 60 into the head holding part 22, the neck holding part 24 can be held in the open position P2 to keep the opening 22b of the head holding part 22 open. This improves the workability when attaching the helical pile 60 to the accessory 20. Also, when pulling out the helical pile 60 using the accessory 20, the neck holding part 24 can be held in the open position P2 to keep the opening 22b of the head holding part 22 open. This improves the workability when pulling out the helical pile 60.

[0082] As shown in Figs. 5, 13, and 20, the positioning mechanism 30 has a stopper 31 movably provided on the head holding part 22. The positioning mechanism 30 has a biasing member 35 that biases the stopper 31. The positioning mechanism 30 has an insertion part 27 formed on the neck holding part 24 and into which the base end 32a of the stopper 31 is inserted using the biasing force of the biasing member 35. Therefore, the stopper 31 can be automatically moved toward the base end 32a by the biasing force of the biasing member 35. Therefore, the neck holding part 24 can be easily held in the open position P2. Moreover, by inserting the base end 32a of the stopper 31 into the insertion part 27, the neck holding part 24 can be maintained in the open position P2. Thus, when the helical pile 60 is inserted into the head holding part 22 or when the helical pile 60 is pulled out using the accessory 20, the neck holding part 24 can be prevented from moving inadvertently. This improves workability.

[0083] 5, 13, and 20, the stopper 31 has a rod-shaped pin 32. The stopper 31 has a tip portion 32b of the pin 32 that penetrates the neck holding portion 24. The stopper 31 has a large diameter portion 33 provided at the tip portion 32b. The stopper 31 has an unlocking portion 34 that protrudes from the large diameter portion 33 toward the base end portion 32a of the pin 32. By moving the stopper 31 against the biasing member 35 and rotating it about its axis, the unlocking portion 34 comes into contact with the first side surface 24d of the neck holding portion 24.

[0084] Therefore, by abutting the unlocking portion 34 against the first side surface 24d of the neck holding portion 24, the stopper 31 can be prevented from moving toward the base end portion 32a. Therefore, the unlocked state of the neck holding portion 24 can be maintained, and the neck holding portion 24 can be moved. When the neck holding portion 24 is locked, the stopper 31 is rotated around its axis, and the biasing force of the biasing member 35 moves the end portion 34c of the unlocking portion 34 toward the base end portion 32a from the first side surface 24d of the neck holding portion 24. This allows the neck holding portion 24 to be maintained in the open position P2. Thus, the neck holding portion 24 can be switched between the locked state and the unlocked state with a simple operation without using any tools.

[0085] 11, 14, and 17, the neck holding part 24 is connected to the head holding part 22 so as to be rotatable about a rotation shaft 28. The neck holding part 24 is provided with a sliding hole 25 that is arc-shaped about the rotation shaft 28 and through which the tip 32b of the pin 32 is inserted. Therefore, when the neck holding part 24 is in an unlocked state, the pin 32 moves within the arc-shaped sliding hole 25 when the neck holding part 24 is rotated about the rotation shaft 28. Therefore, the neck holding part 24 can be rotated smoothly.

[0086] As shown in Figs. 14 and 16, the first side surface 24d of the neck holder 24 is provided with a protrusion 26 that pushes the unlocking portion 34 into the sliding hole 25 when the neck holder 24 is rotated from the closed position P1 (see Fig. 2) to the open position P2 (see Fig. 17). Therefore, the neck holder 24 is rotated to a predetermined angle with the unlocking portion 34 in contact with the first side surface 24d of the neck holder 24. This causes the protrusion 26 to abut against the unlocking portion 34. When the neck holder 24 is further rotated, the protrusion 26 pushes the unlocking portion 34 into the sliding hole 25. This causes the stopper 31 including the unlocking portion 34 to move toward the base end portion 32a due to the biasing force of the biasing member 35, locking the neck holder 24. Thus, the unlocked state of the neck holder 24 can be easily switched to the locked state by simply rotating the neck holder 24.

[0087] As shown in Figs. 10, 14, and 20, the end 34c of the unlocking part 34 becomes thinner toward the base end 32a. Therefore, the frictional force between the end 34c of the unlocking part 34 and the first side surface 24d of the neck holding part 24 can be suppressed. Therefore, when the end 34c of the unlocking part 34 is in contact with the first side surface 24d of the neck holding part 24, the neck holding part 24 can be moved smoothly. Also, when the end 34c of the unlocking part 34 is in contact with the first side surface 24d of the neck holding part 24, the stopper 31 can be rotated smoothly around its axis. This allows the stopper 31 to be rotated around its axis, and the neck holding part 24 to be smoothly switched from the unlocked state to the locked state.

[0088] 4, 7 and 18, the neck holding part 24 is formed with a first insertion part 27a as the insertion part 27 into which the stopper 31 is inserted when the neck holding part 24 is in the closed position P1. The neck holding part 24 is formed with a second insertion part 27b as the insertion part 27 into which the stopper 31 is inserted when the neck holding part 24 is in the open position P2.

[0089] Therefore, the stopper 31 can be inserted into the first insertion portion 27a to hold the neck holding portion 24 in the closed position P1. This can prevent the neck holding portion 24 from moving inadvertently from the closed position P1. This can more reliably hold the head 61 and neck 62 of the helical pile 60. Furthermore, the stopper 31 can be inserted into the second insertion portion 27b to hold the neck holding portion 24 in the open position P2. This can prevent the neck holding portion 24 from moving inadvertently from the open position P2. This can maintain the opening 22b of the head holding portion 22 in an open state. This can improve the ease of use when inserting the helical pile 60 into the head holding portion 22 or when pulling out the helical pile 60 using the accessory 20.

[0090] 21 and 22, a head abutment portion 23 against which the head 61 of the helical pile 60 abuts is provided inside the head holding portion 22. A removably attached holder 40 is provided inside the head holding portion 22. The holder 40 is provided with a second head abutment portion 41 against which the head 61 of the second helical pile 65 abuts at a position lower than the head abutment portion 23. Therefore, by providing the detachable holder 40 inside the head holding portion 22, multiple types of helical piles with different head shapes can be held by the accessory 20. Therefore, the accessory 20 can be used to drive or pull out multiple types of helical piles.

[0091] Next, a second embodiment of the present disclosure will be described with reference to Figs. 24 to 27. A rotary tool accessory 50 of the second embodiment has a head holding part 51 and a neck holding part 53 instead of the head holding part 22 and the neck holding part 24 shown in Fig. 3. The head holding part 51 is integrally connected to the lower part of the mounting part 21. The neck holding part 53 is separate from the head holding part 51 and can be attached and detached to the head holding part 51. The head holding part 51 and the neck holding part 53 cooperate to hold the helical pile 60. In the following description, only the parts different from the first embodiment will be described in detail.

[0092] As shown in Figs. 24 to 27, the head holding part 51 is substantially rectangular box-shaped. The head holding part 51 has a head abutment part 52 that abuts against the head 61 of the helical pile 60 when the head holding part 51 holds the head 61. The head abutment part 52 includes an upper surface 52a that is integrally connected to the mounting part 21, and a back surface 52b that extends downward from the upper surface 52a in a flat shape. The upper surface 52a extends in a flat shape in the horizontal direction. The head 61 abuts against the upper surface 52a, thereby restricting it from moving further upward relative to the head holding part 51. The back surface 52b is provided with a through hole 52c that penetrates in the left-right direction to allow a bolt 54, which will be described later, to be inserted therethrough.

[0093] 24 to 27, head holding part 51 has a flat first side surface 51c extending downward from the front of top surface 52a and extending leftward from the front end of back surface 52b. Head holding part 51 has a flat second side surface 51d extending downward from the rear of top surface 52a and extending leftward from the rear end of back surface 52b. First side surface 51c and second side surface 51d are approximately parallel to each other. The distance between first side surface 51c and second side surface 51d in the front-to-rear direction is approximately the same as or slightly larger than the width of head 61 in the front-to-rear direction.

[0094] As shown in Figs. 25 to 27, the head holder 51 has an opening 51a that opens downward and to the left. The lower part of the opening 51a is approximately C-shaped, which is formed by the lower ends of the back surface 52b, the first side surface 51c, and the second side surface 51d in cooperation with each other. The left part of the opening 51a is approximately C-shaped, which is formed by the left ends of the upper surface 52a, the first side surface 51c, and the second side surface 51d in cooperation with each other. The lower part and the left part of the opening 51a are connected to each other. The opening 51a allows the head 61 of the helical pile 60 to be inserted from the bottom to the top or from the left to the right. The opening 51a also allows the head 61 of the helical pile 60 to be pulled out from the top to the bottom or from the right to the left.

[0095] As shown in Figs. 24 to 27, the neck holding part 53 is provided in a plate shape. The neck holding part 53 has a planar front surface 53a extending in the up-down direction and the front-rear direction. The front surface 53a covers the left part of the opening 51a of the head holding part 51. The front surface 53a is provided with a through hole 53d penetrating in the left-right direction so that a bolt 54 described later can be inserted therethrough. The lower end of the neck holding part 53 is provided with a lower surface 53b. The lower surface 53b is bent from the lower end of the front surface 53a toward the right. The lower surface 53b covers the lower part of the opening 51a when the neck holding part 53 is attached to the head holding part 51. The lower surface 53b is provided with a slit 53c extending in the left-right direction. The opening 51a covered by the lower surface 53b is opened downward only at the portion of the slit 53c. The slit 53c is provided with a front-rear width that allows the neck portion 62 of the helical pile 60 to pass therethrough but restricts the head portion 61 from entering.

[0096] As shown in Figures 24 and 27, the head holding part 51 and the neck holding part 53 are fastened in the left-right direction by a bolt 54 and a nut 54a. The bolt 54 is inserted through the through hole 52c of the head holding part 51, the inside of the loop shape of the head 61, and the through hole 53d of the neck holding part 53. Fastening the head holding part 51 and the neck holding part 53 in the left-right direction suppresses left-right wobbling of the head 61 of the helical pile 60 sandwiched between them. When the neck holding part 53 is attached to the head holding part 51, the lower end 51b of the head holding part 51 is located above the lower surface 53b, which is the lower end of the neck holding part 53.

[0097] As described above, the accessory 50 for a rotary tool has the same effect as the accessory 20 of the first embodiment (see FIG. 1). For example, as shown in FIGS. 24 and 27, the head holding part 51 is moved downward relative to the head 61 of the helical pile 60. As a result, the head 61 is inserted from the opening 51a provided below the head holding part 51. The neck holding part 53 covers the opening 51a of the head holding part 51. As a result, the head 61 can be prevented from coming off the accessory 50, and the neck part 62 can be inserted and held through the slit 53c of the neck holding part 53. Therefore, the head 61 can be held with most of the neck part 62 protruding outside the head holding part 51. This makes it possible to suppress the vertical length of the neck part 62 housed in the accessory 50. Thus, the helical pile 60 can be driven deep into the ground or the like until most of the neck part 62 is buried.

[0098] Next, a third embodiment of the present disclosure will be described with reference to Figs. 28 to 38. A rotary tool accessory 70 of the third embodiment has a mounting part 71, a head holding part 72, and a neck holding part 73 instead of the mounting part 21, the head holding part 22, and the neck holding part 24 shown in Fig. 3. The head holding part 72 is connected to the lower part of the mounting part 71. The neck holding part 73 is separate from the head holding part 72, and is detachable and movable relative to the head holding part 72. The head holding part 72 and the neck holding part 73 cooperate to hold the helical pile 60. In the following description, only the parts different from the first embodiment will be described in detail.

[0099] 28 to 31, head holding part 72 is in the shape of a substantially rectangular box. Head holding part 72 is in the shape of a cylinder that is penetrated in the vertical direction. A substantially rectangular opening 72e is provided at the lower end of head holding part 72. A substantially rectangular upper opening 72f of the same shape as opening 72e is provided at the upper part of head holding part 72. The front-to-rear width of opening 72e and upper opening 72f is substantially the same as or slightly larger than the front-to-rear width of head 61.

[0100] As shown in Figs. 28 to 31, the head holding part 72 has a first holding surface 72a at the left end. The head holding part 72 has a back surface 72b at the right end. The first holding surface 72a and the back surface 72b extend in a plane in the up-down direction and the front-rear direction. The first holding surface 72a and the back surface 72b are approximately parallel to each other. The head holding part 72 has a first side surface 72c connecting the front ends of the first holding surface 72a and the back surface 72b. The head holding part 72 has a second side surface 72d connecting the rear ends of the first holding surface 72a and the back surface 72b. The first side surface 72c and the second side surface 72d extend in a plane in the up-down direction and the left-right direction. The first side surface 72c and the second side surface 72d are approximately parallel to each other. For convenience of explanation, the first holding surface 72a, the first side surface 72c, and the second side surface 72d are shown by virtual lines in Figs. 30 and 31.

[0101] As shown in FIG. 29, the first holding surface 72a, the first side surface 72c, and the second side surface 72d are provided by processing an integral plate-like member. The back surface 72b and the first side surface 72c, and the back surface 72b and the second side surface 72d are connected to each other by, for example, welding or the like. A rectangular recess 72k is provided at a total of four locations, namely, the upper front portion, the upper rear portion, the lower front portion, and the lower rear portion, of the back surface 72b. A rectangular protrusion 72m is provided at the upper right end and the lower right end of the first side surface 72c. A rectangular protrusion 72m is provided at the upper right end and the lower right end of the second side surface 72d. The first side surface 72c and the second side surface 72d can be positioned relative to the back surface 72b by engaging the four recesses 72k with the four protrusions 72m, respectively. This makes it possible to suppress variation in the size of the cylindrical interior of the head holding portion 72.

[0102] As shown in Figs. 29 and 30, a long-hole-shaped rail 72g is provided at the rear of the back surface 72b, extending linearly in the vertical direction and penetrating in the horizontal direction. A guide 74 can slide vertically within the rail 72g. The guide 74 is a screw that can be fastened to the neck holding part 73. The guide 74 moves vertically within the rail 72g, so that the neck holding part 73 can slide between the lower open position P2 and the top closed position P1 (see Fig. 28). The neck holding part 73 is located between the left and right of the first side surface 72c and the second side surface 72d of the head holding part 72. Therefore, the first side surface 72c and the second side surface 72d also serve as guides for the vertical sliding of the neck holding part 73. Two circular through holes 72j penetrating in the horizontal direction are provided at the upper center in the front-rear direction of the back surface 72b. The two through holes 72j are provided side by side in the front-rear direction at approximately the same vertical height.

[0103] As shown in FIGS. 29 and 30, a circular through hole 71a is provided at the top of the mounting part 71, penetrating perpendicular to the axial direction. The pin body 16a of the lock pin 16 can be inserted into the through hole 71a. A pair of two-face width parts 71b extending vertically and parallel to each other are provided at the bottom of the mounting part 71. Two screw holes 71c are provided perpendicular to the pair of two-face width parts 71b. The two screw holes 71c extend in a direction substantially perpendicular to the through hole 71a. Two screws 71d are inserted from right to left through the through hole 72j of the head holding part 72. The two screws 71d are further fastened to the screw holes 71c of the mounting part 71. This connects the mounting part 71 and the head holding part 72.

[0104] As shown in Figures 29 to 33, an upwardly projecting anti-rotation portion 72h is provided at the upper rear portion of the back surface 72b. A tip end 77e of a stopper 77 (described later) abuts against the rear surface of the anti-rotation portion 72h. An upwardly projecting spring bearing surface 72i is provided at the upper front portion of the back surface 72b. The spring bearing surface 72i is provided on the front-rear opposite side to the anti-rotation portion 72h with the mounting portion 71 interposed therebetween. The spring bearing surface 72i abuts against one end of a biasing member 78 which is a coil spring. The biasing member 78 is supported by the spring bearing surface 72i to bias the stopper 77 leftward.

[0105] As shown in Figs. 29 to 31 and 34, the neck holding part 73 is generally in the form of a plate standing up in the vertical direction. A flat second holding surface 73a extending in the vertical and front-rear directions is provided on the left part of the neck holding part 73. The neck holding part 73 has a lower surface 73b connected to the lower end of the second holding surface 73a. The lower surface 73b is bent in an L-shape from the lower end of the second holding surface 73a to the left and extends approximately horizontally. The left-right distance between the first holding surface 72a and the second holding surface 73a is approximately the same as or slightly larger than the left-right thickness of the head 61 and the left-right width of the lower surface 73b. The neck holding part 73 has a slit 73c that divides the lower surface 73b in the front-rear direction. The slit 73c penetrates the lower surface 73b in the vertical direction and extends in the left-right direction. The slit 73c is provided with a size that allows the neck portion 62 of the helical pile 60 to pass therethrough but does not allow the head portion 61 to pass therethrough.

[0106] As shown in Figs. 29 to 31, the neck holding part 73 has an upper surface (head abutment surface) 73d connected to the upper part of the second holding surface 73a. The upper surface 73d is bent in an L-shape to the left from the upper part of the second holding surface 73a and extends approximately horizontally. The upper surface 73d has approximately the same left-right width as the lower surface 73b. The vertical distance between the upper surface 73d and the lower surface 73b is approximately the same as or slightly larger than the vertical height of the head 61. The head 61 of the helical pile 60 is inserted between the upper surface 73d and the lower surface 73b along the second holding surface 73a. At this time, most of the neck 62 protrudes downward from the slit 73c. ​​By protruding the neck 62 longer, the helical pile 60 can be driven deeper.

[0107] As shown in FIGS. 28 to 31, the accessory 70 has a locking mechanism 75 that releasably holds the neck holding part 73. The neck holding part 73 is held in the closed position P1 by the locking mechanism 75. The locking mechanism 75 includes an engagement part 76 provided on the neck holding part 73, and a stopper 77 provided separately from the head holding part 72 and the neck holding part 73. The engagement part 76 extends upward from the upper rear part of the neck holding part 73. The engagement part 76 is provided with a screw hole 73e to which the guide 74 can be fastened from the right side. The guide 74 is fastened to the screw hole 73e after being inserted through the rail 72g of the head holding part 72 from the right side to the left side. This allows the neck holding part 73 to be attached to and detached from the head holding part 72 by the guide 74. The screw hole 73e is provided at a vertical height such that when the guide 74 moves to the lower end of the rail 72g, the neck holding portion 73 moves to the open position P2, and when the guide 74 moves to the upper end of the rail 72g, the neck holding portion 73 moves to the closed position P1.

[0108] As shown in Figs. 28 to 33, the engagement part 76 has a tip surface 76a at its upper end. An inclined surface 76b is provided in communication with the rear end of the tip surface 76a. The inclined surface 76b inclines downward as it approaches the rear. The engagement part 76 has a recess 76c below the inclined surface 76b. The recess 76c is formed by cutting out the rear surface of the engagement part 76 in an L-shape. The tip surface 76a, the inclined surface 76b, and the recess 76c protrude above the upper opening 72f of the head holding part 72 when the neck holding part 73 is in the closed position P1. The tip surface 76a, the inclined surface 76b, and the recess 76c are located inside the cylindrical head holding part 72 when the neck holding part 73 is moved downward from the closed position P1.

[0109] As shown in Figs. 28 to 33, the stopper 77 is a flat plate extending substantially horizontally. The stopper 77 has an attachment portion 77a, an arm 77c, and a second arm 77f. The arm 77c extends rearward from the left portion of the attachment portion 77a. The second arm 77f extends forward from the left portion of the attachment portion 77a. The attachment portion 77a is provided with a circular hole 77b penetrating in the vertical direction. The mounting portion 71 is inserted into the hole 77b. The mounting portion 71 is inserted into the hole 77b from above. The mounting portion 71 is attached to the upper portion of the head holding portion 72 with a screw 71d. This holds the stopper 77 above the head holding portion 72 so that it does not come off the mounting portion 71 and does not move in the vertical direction. The stopper 77 is rotatable in a substantially horizontal direction around the axis of the output axis K.

[0110] As shown in Figs. 28 to 33 and 35, the stopper 77 has a hook (contact surface) 77d at the rear of the arm 77c. The hook 77d protrudes from the arm 77c to the right in a rectangular shape. The hook 77d can contact the inclined surface 76b of the engagement portion 76 at its lower surface. The hook 77d can enter the recess 76c of the engagement portion 76. When the stopper 77 rotates counterclockwise in top view, the hook 77d covers the upper side of the inclined surface 76b. Alternatively, depending on the height of the engagement portion 76, the hook 77d enters and hooks into the recess 76c. When the stopper 77 rotates clockwise in top view, the hook 77d is pushed by the inclined surface 76b and retreats to the left. Alternatively, the engagement between the hook 77d and the recess 76c is released. The right front end of the hook 77d is a tip 77e. When the stopper 77 rotates counterclockwise in top view, the tip 77e comes into contact with the rear surface of the rotation prevention portion 72h. This restricts further counterclockwise rotation. When the stopper 77 rotates clockwise in top view, the tip 77e retreats from the rotation prevention portion 72h.

[0111] As shown in Figures 28 to 33, the stopper 77 has a spring receiving portion 77g at the front of the second arm 77f. A rib protrudes rightward from the spring receiving portion 77g. A biasing member 78 is interposed between the spring receiving portion 77g of the stopper 77 and the spring receiving surface 72i of the head holding portion 72. The biasing member 78 is held by the rib of the spring receiving portion 77g so as not to come off. When the spring receiving portion 77g receives a biasing force from the biasing member 78, the stopper 77 rotates counterclockwise when viewed from above around the output axis K.

[0112] The operation of the locking mechanism 75 will be described with reference to Figures 28 to 33. First, when the neck holding part 73 is located in the open position P2, the engagement part 76 is located below the stopper 77. The stopper 77 is urged counterclockwise in a top view by the urging member 78. The stopper 77 is stopped with the tip 77e abutting against the anti-rotation part 72h. The opening 72e at the lower end of the head holding part 72 is open. At this time, the head 61 of the helical pile 60 can be inserted between the upper surface 73d and the lower surface 73b of the neck holding part 73. The neck 62 of the helical pile 60 protrudes downward from the neck holding part 73 through the slit 73c.

[0113] The neck holding part 73 is slid upward until the engaging part 76 protrudes upward from the upper opening 72f of the head holding part 72. As the neck holding part 73 moves upward, the lower surface (contact surface) of the hanging part 77d abuts while sliding from the upper part to the lower part of the inclined surface 76b. Therefore, the hanging part 77d is pressed against the inclined surface 76b along the inclination direction of the inclined surface 76b. The inclined surface 76b is inclined downward and backward. Therefore, the hanging part 77d is pressed backward. On the other hand, the stopper 77 is held rotatably around the axis of the output axis K. Therefore, the force pushing the hanging part 77d backward is converted into a force that rotates the stopper 77 clockwise as viewed from above. As a result, the stopper 77 gradually rotates clockwise as viewed from above against the biasing force of the biasing member 78. The hanging part 77d retreats to the left of the engaging part 76.

[0114] The neck holding part 73 is further moved upward to the closed position P1. When the recess 76c of the engagement part 76 comes out above the upper opening 72f, the force rotating the stopper 77 in the opposite direction to the biasing direction is released. Therefore, the stopper 77 rotates counterclockwise in a top view due to the biasing force of the biasing member 78. The hook part 77d enters and hooks into the recess 76c. This restricts the upward and downward movement of the neck holding part 73. In this way, the neck holding part 73 can be automatically held at the closed position P1. The first holding surface 72a and the second holding surface 73a cooperate to sandwich the head 61 of the helical pile 60 and hold it inside the accessory 70. The lower surface 73b covers the opening 72e at the lower end of the head holding part 72. Therefore, the tip of the helical portion 63 (see FIG. 1) of the helical pile 60 can be brought into contact with the ground or the like, the rotary tool 1 can be started, and the helical pile 60 can be driven in until most of the neck portion 62 is buried in the ground or the like. In addition, the accessory 70 can also be used to pull out the helical pile 60 that has been driven in until most of the neck portion 62 is buried in the ground or the like.

[0115] To release the neck holder 73 from the lock mechanism 75, the user rotates the stopper 77 clockwise when viewed from above, for example, by hand. This releases the engagement between the hook 77d and the recess 76c, allowing the neck holder 73 to slide up and down.

[0116] As shown in Figs. 36 to 38, the second neck holding part 81 can be attached to the accessory 70 in place of the neck holding part 73 (see Fig. 30). The second neck holding part 81 can hold a second helical pile 65 having a head part 66 with a different shape from the head part 61 (see Fig. 30). For example, the second helical pile 65 is provided by processing a rod material with a smaller diameter than the helical pile 60. For example, the head part 66 of the second helical pile 65 is shorter than the head part 61 of the helical pile 60 in any one or all of the vertical, front-rear, and left-right directions. For convenience of explanation, in Fig. 37, the first holding surface 72a, the first side surface 72c, and the second side surface 72d of the head holding part 72 are shown by virtual lines.

[0117] As shown in Figs. 36 to 38, the second neck holder 81 is generally in the form of a plate standing upright in the vertical direction. A flat second holder surface 81a extending in the vertical and front-rear directions is provided on the left side of the second neck holder 81. The second holder surface 81a is thicker than the second holder surface 73a (see Fig. 34) of the neck holder 73. The second neck holder 81 has a lower surface 81b connected to the lower end of the second holder surface 81a. The lower surface 81b is bent in an L-shape from the lower end of the second holder surface 81a to the left and extends generally horizontally. The left-right distance between the first holder surface 72a and the second holder surface 81a is generally the same as or slightly larger than the left-right thickness of the head 66 and the left-right width of the lower surface 81b. The second neck holder 81 has a slit 81c that divides the lower surface 81b in the front-rear direction. The slit 81c penetrates the lower surface 81b in the up-down direction and extends in the left-right direction. The slit 81c is provided with a size that allows the neck portion 67 of the second helical pile 65 to pass therethrough but does not allow the head portion 66 to pass therethrough.

[0118] 36 and 37, the second neck holding part 81 has an upper surface (head contact surface) 81d connected to the upper part of the second holding surface 81a. The upper surface 81d is bent in an L-shape to the left from the upper part of the second holding surface 81a and extends approximately horizontally. The upper surface 81d has approximately the same left-right width as the lower surface 81b. The vertical distance between the upper surface 81d and the lower surface 81b is approximately the same as or slightly larger than the vertical height of the head 66.

[0119] As shown in Figures 36 and 37, the second neck holding part 81 has a first side 81e connected to the front part of the second holding surface 81a and a second side 81f connected to the rear part of the second holding surface 81a. The first side 81e and the second side 81f are bent in an L-shape to the left from the second holding surface 81a and stand up in the vertical direction. The first side 81e and the second side 81f have approximately the same left-right width as the bottom surface 81b. The front-rear distance between the first side 81e and the second side 81f is approximately the same as or slightly larger than the front-rear width of the head 66. The head 66 of the second helical pile 65 is inserted into a rectangular space surrounded by the top surface 81d, the bottom surface 81b, the first side 81e, and the second side 81f along the second holding surface 81a. At this time, most of the neck part 67 protrudes downward from the slit 81c. Therefore, it can be used when driving the second helical pile 65 deeply and when pulling out the second helical pile 65 that has been driven deeply.

[0120] As shown in Figures 36 and 37, the second neck holding part 81 has an engagement part 76 of the locking mechanism 75. The engagement part 76 extends upward from the upper rear part of the second neck holding part 81. The engagement part 76 is provided with a screw hole 81g to which the guide 74 can be fastened from the right side. The guide 74 removed from the neck holding part 73 (see Figure 29) is inserted through the rail 72g of the head holding part 72 from right to left, and then fastened to the screw hole 81g. This allows the second neck holding part 81 to be attached to the head holding part 72 so as to be slidable in the up and down directions.

[0121] As described above, the rotary tool accessory 70 for holding the helical pile 60 on the rotary tool has a mounting part 71, a head holding part 72, and a neck holding part 73 as shown in Figs. 28 to 31. The mounting part 71 is mounted on the output shaft 15 (see Fig. 1) of the rotary tool 1. The head holding part 72 is provided on the lower part of the mounting part 71 and has a first holding surface 72a and a lower opening 72e. The first holding surface 72a holds the head 61 of the helical pile 60. The neck holding part 73 has a second holding surface 73a, a lower surface 73b, and a slit 73c. ​​The second holding surface 73a is separate from the head holding part 72 and holds the head 61 of the helical pile 60 in cooperation with the first holding surface 72a. The lower surface 73b covers the opening 72e of the head holding part 72. The neck 62 of the helical pile 60 is inserted into the slit 73c.

[0122] Therefore, the head 61 of the helical pile 60 is placed on the neck holding part 73 in the open position P2 while the neck 62 of the helical pile 60 is inserted into the slit 73c. ​​The neck holding part 73 is moved from the open position P2 to the closed position P1 together with the head 61 of the helical pile 60. By this operation, the head 61 is held between the first holding surface 72a of the head holding part 72 and the second holding surface 73a of the neck holding part 73. The lower surface 73b of the neck holding part 73 prevents the head 61 from falling off downward. Therefore, the head 61 can be held while most of the neck 62 protrudes outside the accessory 70. This makes it possible to suppress the vertical length of the neck 62 housed in the accessory 70. Thus, the helical pile 60 can be driven deep into the ground or the like until most of the neck 62 is buried.

[0123] 28, 30, and 31, the neck holding part 73 is attached to the head holding part 72 so as to be slidable between a closed position P1 and an open position P2. The underside 73b of the neck holding part 73 in the closed position P1 covers the opening 72e of the head holding part 72. The underside 73b of the neck holding part 73 in the open position P2 opens the opening 72e. Therefore, the neck holding part 73 performs a simple sliding action relative to the head holding part 72. This allows the accessory 70 to have a simple structure. This improves the ease of assembly when assembling the accessory 70.

[0124] 28, the rotary tool accessory 70 has a locking mechanism 75. The locking mechanism 75 holds the neck holding part 73 in the closed position P1. Therefore, the locking mechanism 75 can reliably hold the neck holding part 73 in the closed position P1. This allows the head part 61 of the helical pile 60 to be stably held. Therefore, the driving operation of the helical pile 60 can be stabilized.

[0125] As shown in Figures 28 to 31, the locking mechanism 75 has an engagement portion 76, a stopper 77, and a biasing member 78. The engagement portion 76 is provided on the neck holding portion 73. The stopper 77 is movably provided on the head holding portion 72. The biasing member 78 biases the stopper 77 in a direction in which it engages with the engagement portion 76. Therefore, the stopper 77 is biased by the biasing member 78 to automatically engage with the engagement portion 76 and maintain the engaged state. This makes it possible to easily hold the neck holding portion 73 in the closed position P1. This improves the efficiency of the work of attaching the helical pile 60 to the accessory 70.

[0126] As shown in Figures 28, 30, and 31, the neck holding part 73 is connected to the head holding part 72 so as to be vertically movable. The stopper 77 is connected to the head holding part 72 so as to be horizontally movable. Therefore, when driving the helical pile 60, the user drives the rotary tool 1 (see Figure 1) while pressing it downward. Therefore, the head holding part 72 and the neck holding part 73 are pressed against each other in the vertical direction in which the neck holding part 73 can move. Therefore, when the rotary tool 1 is driven, the neck holding part 73 can be prevented from moving relative to the head holding part 72. This allows the rotational drive to be efficiently transmitted to the helical pile 60. In addition, by making the movement direction of the neck holding part 73 and the engagement direction of the stopper 77 approximately perpendicular to each other, the neck holding part 73 can be more reliably held at the closed position P1.

[0127] As shown in Figs. 31 to 33, the engagement portion 76 of the neck holding portion 73 has an inclined surface 76b. The inclined surface 76b inclines downward from the upper end. The stopper 77 has an abutment surface 77d that abuts against the inclined surface 76b. When the inclined surface 76b abuts against the abutment surface 77d from below, the stopper 77 moves against the biasing force of the biasing member 78. Therefore, the stopper 77 automatically retreats from the engagement portion 76 against the biasing force of the biasing member 78 simply by moving the neck holding portion 73 upward. When the neck holding portion 73 is moved upward to the closed position P1, the stopper 77 automatically engages with the engagement portion 76 due to the biasing force of the biasing member 78. Therefore, the neck holding portion 73 can be easily held by the stopper 77 without falling downward.

[0128] As shown in Figures 31 to 33, the stopper 77 has an attachment portion 77a, an arm 77c, and a hook portion 77d. The attachment portion 77a is rotatably connected to the head holding portion 72. The arm 77c extends from the attachment portion 77a. The hook portion 77d protrudes from the tip of the arm 77c and is hooked on the engagement portion 76. This makes it possible to increase the torque applied to the hook portion 77d by the biasing force. This makes it possible to provide a stopper 77 that reliably engages with the engagement portion 76 while preventing the biasing member 78 from becoming too large.

[0129] 30 to 33, the head holding part 72 has a rotation stopper 72h. The rotation stopper 72h restricts the rotation of the stopper 77 when the engagement part 76 is disengaged from the stopper 77. Therefore, by restricting the rotation of the stopper 77 in the biasing direction, it becomes easier to retract the stopper 77 from the engagement part 76 in the direction opposite to the biasing direction when the neck holding part 73 is moved upward. This improves the operability of moving the neck holding part 73 upward and holding it at the closed position P1.

[0130] As shown in Figures 28 to 33, the stopper 77 has a second arm 77f. The second arm 77f extends from the mounting portion 77a in the opposite direction to the arm 77c. A biasing member 78 that biases the stopper 77 is provided between the second arm 77f and the head holding portion 72. Therefore, by lengthening the second arm 77f, the biasing force of the biasing member 78 can be made smaller. Therefore, the stopper 77 can be rotated in the biasing direction while the biasing member 78 is made smaller in size.

[0131] As shown in Figs. 29 to 31, the head holding part 72 is cylindrical and has a back surface 72b and a pair of side surfaces 72c and 72d. The back surface 72b is located behind the second holding surface 73a. The pair of side surfaces 72c and 72d connect the back surface 72b and the first holding surface 72a. The back surface 72b is provided with a rail 72g extending in the vertical direction. The second holding surface 73a has a guide 74. The guide 74 is inserted into the rail 72g so as to be movable in the vertical direction. Therefore, the neck holding part 73 can be smoothly guided in the vertical direction along the rail 72g inside the cylindrical head holding part 72. In addition, the neck holding part 73 can be slid in the vertical direction with a simple structure. This improves the ease of assembly when assembling the accessory 70.

[0132] As shown in Figures 29, 30 and 37, the neck holding part 73 is detachably provided on the head holding part 72. A second neck holding part 81 is attached to the head holding part 72 in place of the neck holding part 73. The second neck holding part 81 is structured so that the head 66 of the second helical pile 65, which is smaller than the neck holding part 73, comes into contact with it. Therefore, the second neck holding part 81 corresponding to the second helical pile 60 having a different head shape can be easily assembled in place of the neck holding part 73. Therefore, the accessory 70 can be used to drive in multiple types of helical piles.

[0133] Next, a fourth embodiment of the present disclosure will be described with reference to Figs. 39 to 41. A rotary tool accessory 90 of the fourth embodiment has a mounting part 71, a head holding part 91, a stopper 93, and a biasing member 94, instead of the head holding part 72, the stopper 77, and the biasing member 78 shown in Fig. 28. The head holding part 91 is connected to the lower part of the mounting part 71. The neck holding part 73 is separate from the head holding part 91, and is detachable and movable relative to the head holding part 91. The head holding part 91 and the neck holding part 73 cooperate to hold the helical pile 60. In the following description, only the parts different from the first and third embodiments will be described in detail.

[0134] As shown in Figs. 39 to 41, the head holding part 91 is substantially rectangular box-shaped. The head holding part 91 has substantially the same structure as the head holding part 72 (see Fig. 29). That is, the head holding part 91 is a cylindrical shape that penetrates in the vertical direction and is formed by connecting a first holding surface 91a, a back surface 91b, a first side surface 91c, and a second side surface 91d. The back surface 91b, the first side surface 91c, and the second side surface 91d are positioned and connected to each other by a concave-convex engagement of a concave portion 91k and a convex portion 91m. The head holding part 91 has an opening 91e at the lower end and an upper opening 91f at the upper part. The back surface 91b is provided with an elongated rail 91g that extends linearly in the vertical direction and through which the guide 74 is inserted. Two through holes 91j are provided at the center upper part in the front-rear direction of the back surface 91b for connecting to the mounting part 71 with the screws 71d.

[0135] As shown in Figs. 39 to 41, an upwardly projecting anti-rotation portion 91h is provided at the upper rear portion of the back surface 91b. The anti-rotation portion 91h is provided further rearward than the anti-rotation portion 72h (see Fig. 29). A tip 93e of a stopper 93 abuts against the left surface of the anti-rotation portion 91h. An upwardly projecting spring bearing surface 91i is provided at the upper front portion of the back surface 91b. The spring bearing surface 91i is provided on the front-rear opposite side to the anti-rotation portion 91h, with the mounting portion 71 sandwiched therebetween. The spring bearing surface 91i abuts against a second end 94b of a biasing member 94 which is a torsion spring (torsion spring).

[0136] As shown in Figs. 39 to 41, the accessory 90 has a locking mechanism 92 that releasably holds the neck holding part 73. The neck holding part 73 is held in the closed position P1 by the locking mechanism 92. The locking mechanism 92 includes an engagement part 76 of the neck holding part 73 and a stopper 93 that is provided separately from the head holding part 91 and the neck holding part 73. The stopper 93 is a flat plate extending substantially horizontally. The stopper 93 has an attachment part 93a and an arm 93c. The arm 93c extends rearward from the left part of the attachment part 93a. The attachment part 93a is provided with a circular hole 93b that penetrates in the vertical direction and through which the mounting part 71 is inserted. The stopper 93 is held above the head holding part 91 so as not to come off the mounting part 71 and not to move in the vertical direction. The stopper 93 is rotatable in a substantially horizontal direction around the axis of the output axis K.

[0137] As shown in FIGS. 39 to 41, the stopper 93 has a hook (contact surface) 93d at the rear of the arm 93c. The hook 93d protrudes from the arm 93c to the right in a rectangular shape. The hook 93d can contact the inclined surface 76b of the engagement portion 76 at its lower surface. The hook 93d can enter the recess 76c of the engagement portion 76. When the stopper 93 rotates counterclockwise in top view, the hook 93d covers the upper side of the inclined surface 76b. Alternatively, depending on the height of the engagement portion 76, the hook 93d enters and hooks into the recess 76c. When the stopper 93 rotates clockwise in top view, the hook 93d is pushed by the inclined surface 76b and retreats to the left. Alternatively, the engagement between the hook 93d and the recess 76c is released. The right front end of the hook 93d is a tip 93e. When the stopper 93 rotates counterclockwise in top view, the tip 93e comes into contact with the left surface of the anti-rotation portion 91h. This restricts further counterclockwise rotation. When the stopper 93 rotates clockwise in top view, the tip 93e retreats from the anti-rotation portion 91h.

[0138] As shown in Figures 40 and 41, the mounting portion 93a has a spring insertion hole 93f provided on the outer periphery of the hole 93b. The spring insertion hole 93f is a small-diameter hole extending downward from the upper surface of the mounting portion 93a, and a first end 94a of the urging member 94 is inserted into the spring insertion hole 93f. The annular portion of the urging member 94 is disposed between the upper portion of the mounting portion 71 and the stopper 93 in the up-down direction. The first end 94a is attached to the stopper 93, and the second end 94b abuts against the spring receiving surface 91i. As a result, the urging member 94 urges the urging member 94 counterclockwise around the output axis K when viewed from above.

[0139] The locking mechanism 92 operates in the same manner as the locking mechanism 75 shown in Figures 28 to 33. The accessory 90 described above provides the same effects as the accessory 70 of the third embodiment (see Figure 28). For example, the helical pile 60 can be driven deep into the ground or the like until most of the neck 62 is buried.

[0140] The accessories 20, 50, 70, and 90 of the present embodiment described above can be modified as appropriate. An earth auger has been exemplified as the rotating tool 1 to which the accessories 20, 50, 70, and 90 are attached. Alternatively, the accessories 20, 50, 70, and 90 may be attached to a rotating tool such as an impact driver or an angle drill. By using the accessories 20, 50, 70, and 90 in a rotating tool capable of switching between forward and reverse rotation of the output shaft, the accessories 20, 50, 70, and 90 can be used for both driving and pulling out the helical pile 60. A motor 11 that is driven by power supply has been exemplified as the power source of the rotating tool 1. Alternatively, an internal combustion engine or the like may be used as the power source. A DC rotating tool 1 that uses a rechargeable battery 8 as a power source has been exemplified. Alternatively, the rotating tool may be driven by an AC power source such as a 100V household power source.

[0141] The accessories 20, 50, 70, 90 attached to the output shaft 15 by the lock pin 16 are illustrated. Alternatively, for example, a chuck mechanism may be provided at the lower end of the output shaft 15, and the accessories 20, 50, 70, 90 may be attached to the chuck mechanism. The front-rear and left-right directions of the accessories 20, 50, 70, 90 attached to the output shaft 15 and the front-rear and left-right directions of the helical pile 60 when inserted into or removed from the accessories 20, 50, 70, 90 are not limited to the illustrated directions. For example, the neck holders 24, 53 may be positioned to the right, forward, or backward of the head holders 22, 51. The head 61 of the helical pile 60 may be positioned such that the thickness direction is the front-rear direction.

[0142] In the illustrated embodiment, the neck holding part 24 is provided with two insertion parts 27. Alternatively, the neck holding part 24 may be provided with one insertion part 27 that holds the neck holding part 24 at the closed position P1 or the open position P2. For example, the neck holding part 24 may be provided with three or more insertion parts 27, so that the neck holding part 24 can be held at the closed position P1 and a plurality of open positions.

[0143] In the above embodiment, the protrusion 26 is disposed on the outer periphery of the arc-shaped sliding hole 25. Alternatively, for example, the protrusion 26 may be disposed on the inner periphery of the arc-shaped sliding hole 25. A coil spring is exemplified as the biasing member 35 that biases the stopper 31. Alternatively, for example, an elastic member such as rubber may be used as the biasing member.

[0144] A helical pile 60 having a substantially circular hook-shaped head 61 and a second helical pile 65 having a substantially circular hook-shaped head 66 are exemplified. The present invention is not limited to the exemplified shapes, and can be applied to helical piles of various shapes. For example, the shape of the head may be annular in which the tip of the head contacts or connects to the base end of the head. For example, the shape of the head may be such that the tip of the head is further away from the base end of the head. For example, the shape of the head may be spiral. For example, the shape of the head may be polygonal, such as triangular or rectangular. For example, the head may be long in the vertical direction or the front-to-back direction. For example, the size of the outer circumference of the helical part may be approximately the same as the front-to-back width of the head, and may be larger or smaller. For example, the present invention can be applied to various thicknesses (diameters) of the rod material forming the helical pile. For example, the rod material forming the helical pile does not need to have a constant diameter.

[0145] The head holding part 22 is exemplified as holding the head 61 from multiple directions, such as the top surface 23a, the back surface 23b, and the front surface 22a. Instead of this, for example, a head holding part may be provided that abuts against the head 61 from at least one direction to hold the head 61 so as not to fall off. For example, the head holding parts 72, 91 of the third and fourth embodiments also hold the head 61 from at least one of the first holding surfaces 72a, 91a so as not to fall off.

[0146] In the above example, the first holding surface 72a and the second holding surface 73a, 81a, or the first holding surface 91a and the second holding surface 73a face each other to hold the heads 61, 66. Alternatively, the first holding surface and the second holding surface may be substantially parallel to each other but not facing each other. For example, the first holding surface and the second holding surface may be substantially perpendicular to each other. Even in such a configuration, the first holding surface and the second holding surface can cooperate to hold the heads 61, 66.

[0147] The configuration in which the neck holding parts 73, 81 are slidable in the up and down direction relative to the head holding parts 72, 91 has been exemplified. Instead of this, for example, the neck holding parts may be slidable in the horizontal direction or in an inclined direction including the horizontal direction. For example, the neck holding parts may be slidable relative to the head holding parts and rotatable within a predetermined angle range around the guide 74 or the like.

[0148] The rails 72g and 91g are long holes, and the convex guide 74 is a screw. Alternatively, the rails may be grooved and not penetrate the rear surfaces 72b and 91b. For example, the rails may be convex, and the guides may be slidable concaves that engage with the convex. For example, a bolt and a nut may be attached to the neck holder to serve as the guide.

[0149] Stoppers 77, 93 are shown as being biased to rotate in a horizontal direction. Alternatively, for example, the stoppers may be biased to slide horizontally. For example, the stoppers may be biased to rotate in a vertical direction. A biasing member 78 is shown as a coil spring that generates a biasing force when compressed. Alternatively, the stoppers may be biased by, for example, a tension spring. For example, a biasing member made of an elastic material such as rubber may be used.

[0150] The second neck holding part 81 is illustrated as having five surfaces, namely, a second holding surface 81a, a lower surface 81b, an upper surface 81d, a first side surface 81e, and a second side surface 81f, which hold the head 66 of the second helical pile 65. The second neck holding part may be modified as appropriate depending on the shape of the head to be held. For example, if the head is an ellipse long horizontally, it may be configured without the first and second sides. For example, if the head is triangular, it may be configured with inclined surfaces corresponding to each side of the triangle. For example, if the head is a non-linearly symmetrical spiral, the holding surfaces may be arranged non-linearly symmetrically to match the shape of the head. [Explanation of symbols]

[0151] 1...Rotary tool (earth auger) 2…Tool body 3...handle housing, 3a...grip portion, 3b...battery mounting portion, 3c…Controller housing 4…Main switch 5...Trigger, 5a...Trigger switch 6…Forward / reverse switching lever 7. Controller 8…Battery 10…Motor housing 11...Motor 12...Gear housing 13...reduction mechanism, 13a...direction change mechanism 14...Speed ​​change lever 15...Output shaft, 15a...Through hole 16...lock pin, 16a...pin body, 16b...head, 16c...wire 16d...Engagement part 17……Front grip 18…Reaction force receiving part 19…Auxiliary handle 20...(Rotary tool) Accessories 21... mounting portion, 21a... through hole 22...head holder, 22a...front, 22b...opening, 22c...bottom end 22d...first side surface, 22e...through hole, 22f...second side surface, 22g...through hole 23...Head contact part, 23a...Top surface, 23b...Back surface, 23c...Through hole, 23d...Bent part 24...Neck holding part, 24a...Front, 24b...Bottom surface (lower end), 24c...Slit 24d...first side (outer surface), 24e...through hole, 24f...second side, 24g...through hole 25…Sliding hole 26...Protrusion, 26a...First contact surface, 26b...Second contact surface 27: Insertion portion, 27a: First insertion portion, 27b: Second insertion portion 28…Rotation axis 30... Positioning mechanism 31...Stopper 32: pin; 32a: base end; 32b: tip end; 32c: step 33…Large diameter section 34...unlock portion, 34a...first unlock portion, 34b...second unlock portion 34c...end 35... Urging member 40…Holder 41...Second head contact part, 41a...Top surface, 41b...Slanted surface, 41c...Back surface, 41d...Screw hole 42…Screw 50...(Rotary tool) Accessories 51...head holding part, 51a...opening, 51b...lower end, 51c...first side, 51d...second side 52...Head contact part, 52a...Top surface, 52b...Back surface, 52c...Through hole 53...Neck holding part, 53a...Front, 53b...Bottom surface (lower end), 53c...Slit 53d…Through hole 54...Bolt, 54a...Nut 60…Spiral pile 61...Head 62...Neck 63…Spiral part 65…Second helical pile 66...Head 67...Neck 70...(Rotary tool) Accessories 71... mounting portion, 71a... through hole, 71b... two-face width portion, 71c... screw hole, 71d... screw 72...head holding part, 72a...first holding surface, 72b...back surface, 72c...first side surface 72d...second side, 72e...opening (lower end), 72f...upper opening, 72g...rail 72h: anti-rotation portion, 72i: spring receiving surface, 72j: through hole, 72k: recess, 72m: protrusion 73...Neck holding part, 73a...Second holding surface, 73b...Bottom surface, 73c...Slit 73d...Top surface (head contact surface), 73e...Screw hole 74…Guide 75…Locking mechanism 76: engagement portion, 76a: tip surface, 76b: inclined surface, 76c: recess 77... stopper, 77a... mounting portion, 77b... hole, 77c... arm, 77d... hanging portion (contact surface) 77e...tip, 77f...second arm, 77g...spring receiving part 78... Urging member 81...Second neck holding part, 81a...Second holding surface, 81b...Bottom surface, 81c...Slit 81d...Top surface (head contact surface), 81e...First side, 81f...Second side, 81g...Screw hole 90...(Rotary tool) Accessories 91...head holding part, 91a...first holding surface, 91b...back surface, 91c...first side surface 91d... second side, 91e... opening (lower end), 91f... upper opening, 91g... rail 91h: anti-rotation portion, 91i: spring receiving surface, 91j: through hole, 91k: recess, 91m: protrusion 92...Locking mechanism 93... stopper, 93a... mounting portion, 93b... hole, 93c... arm, 93d... hanging portion (contact surface) 93e...tip, 93f...spring insertion hole 94: biasing member, 94a: first end, 94b: second end P1: Closed position P2…Opening position K...Output axis line

Claims

1. An accessory for a rotary tool that holds a helical pile on a rotary tool, A mounting portion that is mounted on an output shaft of a rotary tool; A head holding portion provided at a lower portion of the mounting portion and holding a head of the helical pile and having an opening downward; An accessory for a rotary tool having a neck holding portion that is separate from the head holding portion, covers the opening of the head holding portion, and has a slit through which the neck of the helical pile is inserted.

2. The rotary tool accessory according to claim 1, The neck holding portion is attached to the head holding portion so as to be movable between a closed position that covers the opening of the head holding portion and an open position that opens the opening.

3. The rotary tool accessory according to claim 2, An accessory for a rotary tool, wherein an upper portion of the neck holder is rotatably connected to the head holder and a lower portion of the neck holder moves up and down.

4. The rotary tool accessory according to claim 3, An accessory for a rotary tool, wherein the lower end of the neck holding portion is positioned higher than the lower end of the head holding portion when the neck holding portion is in the open position.

5. The rotary tool accessory according to any one of claims 2 to 4, An accessory for a rotary tool having a positioning mechanism that holds the neck holding portion in the open position.

6. The rotary tool accessory according to claim 5, The positioning mechanism is an accessory for a rotary tool that has a stopper that is movably mounted on the head holding portion, a biasing member that biases the stopper, and an insertion portion formed on the neck holding portion and into which the base end of the stopper is inserted using the biasing force of the biasing member.

7. The rotary tool accessory according to claim 6, The stopper has a rod-shaped pin, a tip portion of the pin that penetrates the neck holding portion, a large diameter portion provided at the tip portion, and an unlock portion that protrudes from the large diameter portion toward the base end side of the pin, An accessory for a rotary tool in which the unlocking portion abuts against the outer surface of the neck holding portion by moving the stopper against the biasing member and rotating it around its axis.

8. The rotary tool accessory according to claim 7, The neck support part is rotatably connected to the head support part around a rotation axis, An accessory for a rotary tool, wherein the neck holding portion is provided with a sliding hole that is arc-shaped around the rotation axis and through which the tip of the pin is inserted.

9. The rotary tool accessory according to claim 8, An accessory for a rotary tool, wherein an outer surface of the neck holding portion is provided with a protrusion that pushes the unlocking portion into the sliding hole when the neck holding portion is rotated from the closed position to the open position.

10. The rotary tool accessory according to any one of claims 7 to 9, An accessory for a rotary tool, wherein an end of the unlocking portion becomes thinner toward the base end.

11. The rotary tool accessory according to any one of claims 6 to 10, An accessory for a rotary tool, wherein the neck holding portion has as the insertion portion a first insertion portion into which the stopper is inserted when the neck holding portion is in the closed position, and a second insertion portion into which the stopper is inserted when the neck holding portion is in the open position.

12. An accessory for a rotary tool according to any one of claims 1 to 11, A head abutment portion against which the head of the helical pile abuts is provided inside the head holding portion, An accessory for a rotary tool, comprising a holder that is removably attached inside the head holding portion, and a second head abutment portion that is provided on the holder and against which the head of a second helical pile abuts at a position lower than the head abutment portion.

13. An accessory for a rotary tool that holds a helical pile on a rotary tool, A mounting portion that is mounted on an output shaft of a rotary tool; A head holding portion provided at a lower portion of the mounting portion and having a first holding surface and a lower opening for holding the head of the helical pile; An accessory for a rotary tool having a second holding surface that is separate from the head holding portion and cooperates with the first holding surface to hold the head of the helical pile, and a neck holding portion having a lower surface covering the opening of the head holding portion and a slit through which the neck of the helical pile is inserted.

14. The rotary tool accessory according to claim 13, The neck holder is an accessory for a rotary tool that is attached to the head holder so as to be slidable between a closed position in which the undersurface of the neck holder covers the opening of the head holder and an open position in which the undersurface opens the opening.

15. The rotary tool accessory according to claim 14, A rotary tool accessory having a locking mechanism that holds the neck holder in the closed position.

16. 16. The rotary tool accessory according to claim 15, The locking mechanism is an accessory for a rotary tool having an engagement portion provided on the neck holding portion, a stopper movably provided on the head holding portion, and a biasing member that biases the stopper in a direction engaging with the engagement portion.

17. 17. The rotary tool accessory according to claim 16, The neck support part is connected to the head support part so as to be vertically movable, The stopper is a rotary tool accessory that is connected to the head holding portion so as to be horizontally movably connected thereto.

18. 18. The rotary tool accessory according to claim 17, The engagement portion of the neck holder has an inclined surface that slopes downward from an upper end, The stopper has an abutment surface that abuts against the inclined surface, and the inclined surface abuts against the abutment surface from below, causing the stopper to move against the biasing force of the biasing member.

19. An accessory for a rotary tool according to any one of claims 16 to 18, The stopper is an accessory for a rotary tool having an attachment portion rotatably connected to the head holding portion, an arm extending from the attachment portion, and a hanging portion protruding from the tip of the arm and hooked onto the engagement portion.

20. 20. The rotary tool accessory according to claim 19, The head holding portion has a rotation preventing portion that restricts rotation of the stopper when the engagement portion is disengaged from the stopper.

21. 21. The rotary tool accessory according to claim 19 or 20, The stopper has a second arm extending from the mounting portion in a direction opposite to the arm, A rotary tool accessory, comprising: a biasing member for biasing the stopper, the biasing member being provided between the second arm and the head holding portion.

22. An accessory for a rotary tool according to any one of claims 14 to 21, The head holding portion is cylindrical and has a back surface located on the back side of the second holding surface and a pair of side surfaces connecting the back surface and the first holding surface, A rail extending in the vertical direction is provided on the back surface, The second holding surface is an accessory for a rotary tool having a guide that is inserted into the rail so as to be movable in the vertical direction.

23. An accessory for a rotary tool according to any one of claims 14 to 22, The neck holding part is detachably provided to the head holding part, A second neck support part is attached to the head support part instead of the neck support part, An accessory for a rotary tool, wherein the second neck holding portion is structured to be abutted by the head of a second helical pile which is smaller than the neck holding portion.

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