CN213381293U

CN213381293U - Screw fastening tool

Info

Publication number: CN213381293U
Application number: CN202021780361.XU
Authority: CN
Inventors: 平林德夫; 近藤友幸; 川合靖仁; 塚本功儿
Original assignee: Makita Corp
Current assignee: Makita Corp
Priority date: 2019-09-30
Filing date: 2020-08-24
Publication date: 2021-06-08
Anticipated expiration: 2030-08-24
Also published as: JP2021053734A; DE202020105522U1

Abstract

Provided is a screw fastening tool with excellent operability. It is provided with: the tool holder includes a motor, an output shaft rotated by power transmitted from the motor, and a tool holding device for holding a tool inserted into an insertion hole of the output shaft. The tool holding device includes: the tool bit includes a locking portion that is supported by an output shaft and is movable between a locking position where a tip tool is locked and a releasing position where the locking is released, a 1 st elastic member that generates an elastic force that moves a locking member to the locking position, a sleeve that is provided around the output shaft and is movable between a blocking position where the locking member is blocked from moving radially outward and a permitting position where the locking member is permitted to move radially outward, a 2 nd elastic member that generates an elastic force to move the sleeve to the blocking position, and a positioning member that is fixed to an outer surface of the output shaft and positions the sleeve at the blocking position. In a cross section parallel to the rotation axis of the output shaft, a contact surface of the positioning member contacting the sleeve is a curved surface.

Description

Screw fastening tool

Technical Field

The utility model relates to a screw fastening tool.

Background

In the technical field relating to screw fastening tools, there are known: patent document 1 discloses an electric power tool provided with a tool holding device.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 3652918

SUMMERY OF THE UTILITY MODEL

The screw fastening tool includes: and an output shaft rotated by power transmitted from the motor. The tip end tool is inserted into the insertion hole of the output shaft. The tool holding device holds a tool at the tip end inserted into an insertion hole of an output shaft. The tool holder is operated to attach and detach the tip tool. If the operability of the tool holding device is not good, the work efficiency of the operator may be reduced.

An object of the utility model is to enable the operability of screw fastening instrument to become good.

According to the utility model discloses, a screw fastening is provided, screw fastening instrument possesses: a motor; an output shaft that rotates by power transmitted from the motor; and a tool holding device for holding a tool at a tip end inserted into an insertion hole of the output shaft, the tool holding device including: a lock member supported by the output shaft and movable between a lock position for locking the tip tool and a release position for releasing the lock; a 1 st elastic member that generates an elastic force for moving the lock member toward the lock position; a sleeve that is movable around the output shaft between a blocking position that blocks movement of the lock member radially outward and an allowing position that allows movement of the lock member radially outward; a 2 nd elastic member that generates an elastic force to move the sleeve toward the stopping position; and a positioning member fixed to an outer surface of the output shaft and positioning the sleeve at the stopping position, wherein a contact surface of the positioning member, which is in contact with the sleeve, is a curved surface in a cross section parallel to a rotation axis of the output shaft.

According to the utility model discloses, can make screw fastening tool's operability become good.

Drawings

Fig. 1 is a perspective view showing an electric power tool according to embodiment 1.

Fig. 2 is a longitudinal sectional view of a part of the electric power tool according to embodiment 1.

Fig. 3 is an enlarged longitudinal sectional view of an upper portion of the electric power tool according to embodiment 1.

Fig. 4 is an enlarged transverse cross-sectional view of an upper portion of the electric power tool according to embodiment 1.

Fig. 5 is a transverse cross-sectional view showing the tool holding device according to embodiment 1.

Fig. 6 is a longitudinal sectional view showing the tool holding device according to embodiment 1.

Fig. 7 is a sectional view showing a tool holding device according to embodiment 1.

Fig. 8 is an enlarged cross-sectional view of a part of the tool holding device according to embodiment 1.

Fig. 9 is an enlarged cross-sectional view of a part of the tool holding device according to embodiment 1.

Fig. 10 is a perspective view showing a positioning member according to embodiment 1.

Fig. 11 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to an output shaft.

Fig. 12 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to an output shaft.

Fig. 13 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to an output shaft.

Fig. 14 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to an output shaft.

Fig. 15 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to an output shaft.

Fig. 16 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to an output shaft.

Fig. 17 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to an output shaft.

Fig. 18 is a cross-sectional view showing an operation of attaching the tip end tool according to embodiment 1 to the output shaft.

Fig. 19 is a cross-sectional view showing an operation of detaching the tip end tool according to embodiment 1 from the output shaft.

Fig. 20 is a cross-sectional view showing an operation of detaching the tip end tool according to embodiment 1 from the output shaft.

Fig. 21 is a cross-sectional view showing an operation of detaching the tip end tool according to embodiment 1 from the output shaft.

Fig. 22 is an enlarged transverse cross-sectional view of an upper portion of the electric power tool according to embodiment 2.

Fig. 23 is a transverse cross-sectional view showing the tool holding device according to embodiment 2.

Fig. 24 is a sectional view showing a tool holding device according to embodiment 2.

Fig. 25 is a sectional view showing a tool holding device according to embodiment 2.

Fig. 26 is a transverse sectional view showing the tool holding device according to embodiment 3.

Fig. 27 is a perspective view showing the drawer device according to embodiment 3.

Fig. 28 is a transverse sectional view showing the tool holding device according to embodiment 3.

Description of reference numerals:

1 … electric tool (screw fastening tool); 2 … outer shell; 2L … left shell; 2R … right housing; 2S … screw; 3 … rear shell; 4 … hammer case; 5 … battery mounting part; 6 … motor; 7 … speed reduction mechanism; 8 … a main shaft; 9 … striking mechanism; 10 … anvil (output shaft); 10a … anvil body; 10B … anvil projections; 10S … outer surface; 11a … tool holding means; 11B … tool holding means; 11Bb … tool holding means; 11C … tool holding means; 12 … fan; 13 … a controller; 14 … trigger switch; 14a … trigger component; 14B … switching circuit; 15 … positive and negative switching lever; 16 … operating panel; 17 … mode selector switch; 18 … lamp; 19 … air suction opening; 20a … exhaust port No. 1; 20B … exhaust port No. 2; 21 … a motor housing; 21a … cylindrical portion; 22 … a handle; 23 … controller housing part; 24 … bearing retainer; 25 … battery pack; 26 … stator; 27 … a rotor; 28 … a stator core; 29 … front insulator; 29S … screw; 30 … rear insulator; 31 … coil; 32 … rotor shaft; 33 … rotor core; 34 … permanent magnet; 35 … permanent magnet for sensor; 36 … resin sleeve; 37 … sensor substrate; 38 … coil terminal; 39 … front bearing; 40 … rear bearing; 41 … pinion gear; 42 … planetary gear; 43 … internal gear; 44 … flange portion; 45 … a stem portion; 46 … rear bearing; 47 … hammer; 47a … hammer body; 47B … hammer projections; 48 … balls; 49 … coil spring; 50 … spindle groove; 51 … hammer grooves; 52 … convex portions; 53 … recess; 54 … gasket; 55 … is inserted into the hole; 55a … opening; 55B … bottom surface; 56 … front bearing; 57 … pore; 58 … hole; a 61 … liner; 62 … controller housing; 63 … opening; 64 … operating switch; 71 … ball bearing (locking member); 72 … elastic member No. 1; 73 … a sleeve; 73a … sleeve body; 74 … elastic 2 part; 75 … a positioning member; 75S … contact surface; 76 … piston member; 76B … bottom plate portion; a 76C … space; 76T … peripheral wall portion; 76F … flange portion; 76H … opening; 77 … pulling out the elastic component; 78 … washer; 79 … stop ring; 79R … recess; 80 … groove 1; 81 … through holes; 82 … support recess; 83 … groove 3; 84 … bottom; 85 … wall portions; 86 … taper; 87 … groove 2; 88 … protrusions; 88S … inner surface; 88T … front surface; 89 part 1; 90 … part 2; 91 … recess 2; 92 … stop ring; 93 … stop member; 94 … recess 1; 95 … inclined plane; 96 … recess No. 3; 101 … supply port 1; 101R … flow path 1; 102 … supply port 2; 102R … flow path 2; 103 … internal space; 200 … pull-out device; AX … rotating shaft; BT … front end tool; b1 … fitting part; b2 … groove part; b3 … taper; a B4 … processing section; da … winding diameter; db … distance; dc … inner diameter; dt … inner diameter; ds … outer diameter; ra … depth; rb … radius; angle θ ….

Detailed Description

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiment. The constituent elements of the embodiments described below can be combined as appropriate. In addition, some of the components may not be used.

In the present embodiment, the positional relationship of the respective portions will be described using terms of left, right, front, rear, upper and lower. These terms refer to relative positions or directions with reference to the center of the screw tightening tool. In the present embodiment, the screw tightening tool is an electric power tool 1 having an output shaft 10.

In the present embodiment, a direction parallel to the rotation axis AX of the output shaft 10 is appropriately referred to as an axial direction, a direction around the rotation axis AX is appropriately referred to as a circumferential direction or a rotational direction, and a radiation direction of the rotation axis AX is appropriately referred to as a radial direction.

The rotation axis AX extends in the front-rear direction. One axial side is the front and the other axial side is the back. In the radial direction, a position close to the rotation axis AX or a direction close to the rotation axis AX is appropriately referred to as a radially inner side, and a position away from the rotation axis AX or a direction away from the rotation axis AX is appropriately referred to as a radially outer side.

[ embodiment 1 ]

< electric tool >

Fig. 1 is a perspective view showing an electric power tool 1 according to the present embodiment. Fig. 2 is a longitudinal sectional view showing a part of the electric power tool 1 according to the present embodiment. Fig. 3 is a vertical sectional view showing an enlarged upper portion of the electric power tool 1 according to the present embodiment. Fig. 4 is a lateral cross-sectional view showing an enlarged upper portion of the electric power tool 1 according to the present embodiment. In the present embodiment, the power tool 1 is an impact driver.

As shown in fig. 1, 2, and 3, the electric power tool 1 includes: the tool holder includes a housing 2, a rear case 3, a hammer case 4, a battery mounting portion 5, a motor 6, a reduction mechanism 7, a spindle 8, a striking mechanism 9, an output shaft 10, a tool holding device 11A, a fan 12, a controller 13, a trigger switch 14, a forward/reverse switching lever 15, an operation panel 16, a mode switching switch 17, and a lamp 18.

The housing 2 is made of synthetic resin. In the present embodiment, the housing 2 is made of nylon. The housing 2 includes: a left housing 2L, and a right housing 2R disposed at a right position of the left housing 2L. The left housing 2L and the right housing 2R are fixed by a plurality of screws 2S. The housing 2 is constituted by a pair of half-divided housings.

The housing 2 has: a motor housing portion 21, a grip portion 22 disposed at a position below the motor housing portion 21, and a controller housing portion 23 disposed at a position below the grip portion 22.

The motor housing portion 21 is cylindrical. The motor housing portion 21 is configured to house at least a part of the motor 6.

The grip 22 protrudes downward from the motor housing 21. The trigger switch 14 is provided on the grip portion 22. The grip portion 22 is held by a worker.

The controller housing portion 23 is connected to the lower end of the grip portion 22. The controller housing section 23 is used to house the controller 13. The controller housing portion 23 has an outer dimension larger than that of the grip portion 22 in the front-rear direction and the left-right direction, respectively.

The rear case 3 is made of synthetic resin. The rear case 3 is disposed: a rear position of the motor housing portion 21. The rear case 3 accommodates at least a part of the fan 12. The rear case 3 is configured to: the opening at the rear of the motor housing portion 21 is covered. The rear housing 3 is fixed to the motor housing portion 21 by screws.

The motor housing portion 21 has an air inlet 19. The motor housing portion 21 has a 1 st exhaust port 20A. The 1 st exhaust port 20A is formed in: a cylindrical portion 21A at the rear of the motor housing portion 21. The rear housing 3 has the 2 nd exhaust port 20B. The air in the external space of the housing 2 flows into the internal space of the housing 2 through the air inlet 19. The air in the inner space of the casing 2 passes through the 1 st exhaust port 20A and then passes through the 2 nd exhaust port 20B. The air in the internal space of the housing 2 flows out to the external space of the housing 2 through the 1 st exhaust port 20A and the 2 nd exhaust port 20B.

The hammer case 4 is made of metal. In the present embodiment, the hammer case 4 is made of aluminum. The hammer case 4 is disposed: a front position of the motor housing portion 21. The hammer case 4 is cylindrical. The inner diameter of the front portion of the hammer housing 4 is smaller than the inner diameter of the rear portion of the hammer housing 4. The rear of the hammer housing 4 is inserted into: the front of the motor housing 21 is open. The rear portion of the hammer case 4 is fitted into: inside the motor housing portion 21. The motor housing portion 21 and the hammer case 4 are connected by a bearing holder 24. At least a portion of the bearing retainer 24 is configured to: an inner position of the hammer housing 4.

The hammer case 4 is used to house at least a part of the reduction mechanism 7, the main shaft 8, the striking mechanism 9, and the output shaft 10. At least a part of the speed reduction mechanism 7 is disposed: the inboard position of the bearing retainer 24.

The battery mounting portion 5 is formed at a lower portion of the controller accommodating portion 2. Battery assembly 5 is connected to battery pack 25. Battery pack 25 is mounted on battery mounting portion 5. Battery pack 25 is attachable to and detachable from battery mounting portion 5. The battery pack 25 includes secondary batteries. In the present embodiment, the battery pack 25 includes a rechargeable lithium ion battery. The battery pack 25 can supply power to the electric power tool 1 by being mounted on the battery mounting portion 5. The motor 6 is driven based on the electric power supplied from the battery pack 25. Controller 13 and operation panel 16 operate based on the electric power supplied from battery pack 25.

The motor 6 is a power source of the electric power tool 1. The motor 6 is an inner rotor type brushless motor. The motor 6 has: a stator 26, and a rotor 27 disposed at a position inside the stator 26.

The stator 26 has: the stator core 28, a front insulator 29 provided at a front position of the stator core 28, a rear insulator 30 provided at a rear position of the stator core 28, and a plurality of coils 31 mounted on the stator core 28 via the front insulator 29 and the rear insulator 30.

The stator core 28 includes a plurality of steel plates stacked one on another. The steel plate is: a metal plate containing iron as a main component. The stator core 28 has a cylindrical shape. The stator core 28 includes: a plurality of teeth for supporting the coil 31. The front insulator 29 and the rear insulator 30 are: an electrical insulating member made of synthetic resin. The front insulator 29 is configured to: covering a portion of the surface of the tooth. The rear insulator 30 is configured to: covering a portion of the surface of the tooth. The coil 31 is disposed around the teeth via the front insulator 29 and the rear insulator 30. The coil 31 and the stator core 28 are electrically insulated by a front insulator 29 and a rear insulator 30.

The rotor 27 rotates about the rotation axis of the rotor 27. The rotation axis of the rotor 27 coincides with the rotation axis AX of the output shaft 10. The rotor 27 rotates about the rotation axis AX. The rotor 27 has: a rotor shaft 32, a rotor core 33 disposed around the rotor shaft 32, a permanent magnet 34 disposed around the rotor core 33, and a sensor permanent magnet 35. The rotor shaft 32 extends in the axial direction. The rotor core 33 is cylindrical. The rotor core 33 includes: a plurality of laminated steel sheets. The permanent magnet 34 has a cylindrical shape. The permanent magnet 34 includes: a 1 st permanent magnet of a 1 st polarity, and a 2 nd permanent magnet of a 2 nd polarity. The 1 st permanent magnet and the 2 nd permanent magnet are alternately arranged in the circumferential direction, thereby forming a cylindrical permanent magnet 34. The sensor permanent magnet 35 is disposed: the rotor core 33 and the permanent magnets 34. At least a part of the resin sleeve 36 is disposed: the sensor uses the inner position of the permanent magnet 35. The resin sleeve 36 is cylindrical. The resin sleeve 36 is disposed: the forward position of the rotor shaft 32.

The front insulator 29 is provided with: a sensor substrate 37 and a coil terminal 38. The sensor substrate 37 and the coil terminal 38 are fixed to the front insulator 29 by screws 29S. The sensor substrate 37 includes: an annular circuit board, and a rotation detection element supported by the circuit board. The rotation detecting element detects the position of the sensor permanent magnet 35 of the rotor 27, thereby detecting the position of the rotor 27 in the rotational direction. The coil terminals 38 are used to connect the plurality of coils 31 with 2 power lines from the controller 13.

The rotor shaft 32 is rotatably supported by a front bearing 39 and a rear bearing 40. The front bearing 39 is held by the bearing holder 24. The rear bearing 40 is held to the rear housing 3. The front bearing 39 is used to support the front portion of the rotor shaft 32. The rear bearing 40 is used to support the rear portion of the rotor shaft 32. The distal end portion of the rotor shaft 32 is disposed in the internal space of the hammer case 4 through the opening of the bearing holder 24.

A pinion gear 41 is provided at the tip end of the rotor shaft 32. The rotor shaft 32 is connected to the reduction mechanism 7 via a pinion gear 41.

The speed reduction mechanism 7 is disposed: the front position of the motor 6. The speed reduction mechanism 7 is used to couple the rotor shaft 32 and the main shaft 8. The speed reduction mechanism 7 transmits power generated by the motor 6 to the main shaft 8. The speed reduction mechanism 7 rotates the main shaft 8 at a rotational speed lower than the rotational speed of the rotor shaft 32. The reduction mechanism 7 includes a planetary gear mechanism.

The speed reduction mechanism 7 includes: a plurality of planetary gears 42 disposed around the pinion gear 41, and an internal gear 43 disposed around the plurality of planetary gears 42. The plurality of planetary gears 42 are respectively meshed with the pinions 41. The planetary gear 42 is rotatably supported by the main shaft 8 via a pin. The internal gear 43 includes: internal teeth that mesh with the planetary gears 42. The internal gear 43 is fixed to the hammer case 4 に. The internal gear 43 cannot always rotate relative to the hammer case.

When the rotor shaft 32 is rotated by driving of the motor 6, the pinion gear 41 is rotated, and the planetary gear 42 revolves around the pinion gear 41. The planetary gear 42 revolves while meshing with the internal teeth of the internal gear 43. The main shaft 8 connected to the planetary gear 42 via a pin rotates at a rotational speed lower than the rotational speed of the rotor shaft 32 by the revolution of the planetary gear 42.

The main shaft 8 is disposed: the front position of the motor 6. At least a part of the main shaft 8 is disposed: the front position of the speed reducing mechanism 7. The main shaft 8 has: a flange 44, and a rod 45 projecting forward from the flange 44. The planetary gear 42 is rotatably supported by the flange portion 44 via a pin.

The main shaft 8 rotates around the rotation axis of the main shaft 8. The rotation axis of the main shaft 8 coincides with the rotation axis AX of the output shaft 10. The main shaft 8 rotates about a rotation axis AX. The main shaft 8 is rotatably supported by a rear bearing 46. The rear bearing 46 is held by the bearing holder 24. The rear bearing 46 supports the rear end of the main shaft 8.

The main shaft 8 has: a 1 st supply port 101 for supplying lubricating oil, and a 2 nd supply port 102 for supplying lubricating oil. The lubricating oil includes grease (grease). The 1 st supply port 101 and the 2 nd supply port 102 are provided in the rod portion 45, respectively. The main shaft 8 has: an internal space 103 for containing lubricating oil. The 1 st supply port 101 is connected to the internal space 103 via the 1 st flow path 101R. The 2 nd supply port 102 is connected to the internal space 103 via the 2 nd flow path 102R. The lubricating oil is supplied from the 1 st supply port 101 and the 2 nd supply port 102 to at least a part of the periphery of the main shaft 8 by the centrifugal force of the main shaft 8.

The striking mechanism 9 strikes the output shaft 10 in the rotational direction based on the rotation of the main shaft 8. The striking mechanism 9 has: a hammer 47 disposed around the main shaft 8, balls 48 disposed between the main shaft 8 and the hammer 47, and a coil spring 49 supported by the main shaft 8 and the hammer 47, respectively. The hammer 47 is disposed: further forward than the speed reduction mechanism 7.

The hammer 47 has a cylindrical shape. The hammer 47 is disposed around the rod 45. The hammer 47 has: for positioning the hole 57 of the rod portion 45. The hammer 47 is rotatable together with the main shaft 8.

The hammer 47 rotates about the rotation axis of the hammer 47. The rotation axis of the hammer 47 coincides with the rotation axis AX of the output shaft 10. The hammer 47 rotates about the rotation axis AX.

The balls 48 are made of metal such as steel. The balls 48 are disposed between the rod 45 and the hammer 47. The main shaft 8 has: a spindle recess 50 for accommodating at least a portion of the ball 48. A spindle recess 50 is provided in a portion of the outer surface of the stem portion 45. The hammer 47 has: a hammer slot 51 for disposing at least a portion of the ball 48. The hammer groove 51 is provided with: a portion of the inner surface of the hammer 47. The balls 48 are disposed between the spindle groove 50 and the hammer groove 51. The balls 48 can roll inside the spindle groove 50 and inside the hammer groove 51, respectively. The hammer 47 is movable with the balls 48. The spindle 8 and the hammer 47 are capable of relative movement in the axial direction and the rotational direction within a movable range defined by the spindle groove 50 and the hammer groove 51, respectively.

The coil spring 49 produces: and an elastic force for moving the hammer 47 forward. The coil spring 49 is disposed between the flange 44 and the hammer 47. An annular projection 52 is provided on the front surface of the flange 44. The convex portion 52 protrudes forward from the peripheral edge portion of the front surface of the flange portion 44. An annular recess 53 is provided on the rear surface of the hammer 47. The recess 53 is recessed toward the front from the rear surface of the hammer 47. A washer 54 is provided inside the recess 53. The rear end portion of the coil spring 49 is disposed: the projecting portion 52 is supported by the flange portion 44 at a position inside. The front end of the coil spring 49 is disposed: the recess 53 is supported by a washer 54 at a position inside the recess.

The output shaft 10 rotates about the rotation axis AX by the power transmitted from the motor 6. The output shaft 10 is disposed: a forward position of the hammer 47. In the present embodiment, the output shaft 10 includes: impacting the anvil of the driver. In the following description, the output shaft 10 is appropriately referred to as an anvil 10.

The anvil 10 has: an insertion hole 55 for inserting the tip tool BT. An insertion hole 55 is provided at the front end portion of the anvil 10. The front end tool BT is fitted to the anvil 10. Further, the anvil 10 has: a hole 58 for disposing the front end of the rod portion 45. An aperture 58 is provided at the rear end of the anvil 10. The tip end of the rod portion 45 is disposed in the hole 58.

The anvil 10 is rotatable together with the hammer 47. The anvil 10 rotates about the rotation axis AX. The anvil is rotatably supported by a pair of front bearings 56. A pair of front bearings 56 are retained to the hammer housing 4.

The hammer 47 has: a tubular hammer body 47A, and a hammer projection 47B provided at the front of the hammer body 47A. The hammer projection 47B is provided in 2 pieces. The hammer projection 47B projects forward from the front of the hammer body 47A.

The anvil 10 has: a rod-shaped anvil body 10A, and an anvil protrusion 10B provided at the rear portion of the anvil body 10A. The insertion hole 55 is provided with: the front end of the anvil body 10A. The anvil projections 10B are provided in 2 numbers. The anvil projection 10B projects from the rear portion of the anvil body 10A toward the radially outer side.

The hammer protrusion 47B is contactable with the anvil protrusion 10B. When the motor 6 is driven in a state where the hammer protrusion 47B is in contact with the anvil protrusion 10B, the anvil 10 rotates together with the hammer 47 and the main shaft 8.

The anvil 10 is struck in the rotational direction by a hammer 47. For example, in the screw fastening work, when the load acting on the anvil 10 becomes high, there are cases where: the anvil 10 cannot be rotated only by the power generated by the motor 6. When the anvil 10 cannot be rotated by only the power generated by the motor 6, the rotation of the anvil 10 and the hammer 47 is stopped. The spindle 8 and the hammer 47 are movable relative to each other in the axial direction and the circumferential direction by balls 48. Even if the hammer 47 stops rotating, the rotation of the main shaft 8 is continued by the power generated by the motor 6. When the spindle 8 rotates while the hammer 47 stops rotating, the balls 48 move rearward while being guided by the spindle groove 50 and the hammer groove 51. The hammer 47 receives a force from the balls 48 and moves rearward along with the balls 48. That is, in a state where the rotation of the anvil 10 is stopped, the hammer 47 moves rearward as the main shaft 8 rotates. By moving the hammer 47 rearward, the contact between the hammer projection and the anvil projection is released.

The coil spring 49 produces: and a spring force for moving the hammer 47 forward. The hammer 47 moved to the rear is moved forward by the elastic force of the coil spring 49. When the hammer 47 moves forward, a force in the rotational direction is applied from the balls 48. That is, the hammer 47 moves forward while rotating. When the hammer 47 moves forward while rotating, the hammer protrusion 47B contacts the anvil protrusion 10B while rotating. Accordingly, the anvil protrusion 10B is struck by the hammer protrusion 47B in the rotational direction. Acting on the anvil 10: the power of the motor 6 and the inertia force of the hammer 47. Therefore, the anvil 10 can be rotated around the rotation axis AX with a high torque.

The tool holder 11A is disposed around the front portion of the anvil 10. The tool holding device 11A is used to hold the leading end tool BT inserted into the insertion hole 55 of the anvil 10.

Fan 12 is disposed at a position rearward of motor 6. The fan 12 generates: the air flow cooling the motor 6. Fan 12 is secured to at least a portion of rotor 27. Fan 12 is fixed to the rear portion of rotor shaft 32 via a bush 61. Fan 12 is disposed between rear bearing 40 and stator 26. The fan 12 is rotated by the rotation of the rotor 27. When rotor shaft 32 rotates, fan 12 rotates together with rotor shaft 32. When the fan 12 is rotated, air in the external space of the casing 2 flows into the internal space of the casing 2 through the air inlet 19. The air flowing into the internal space of the housing 2 flows through the internal space of the housing 2, thereby cooling the motor 6. The air flowing through the internal space of the housing 2 flows out to the external space of the housing 2 through the 1 st exhaust port 20A and the 2 nd exhaust port 20B.

The controller 13 is housed in the controller housing portion 23. The controller 13 outputs: a control signal for controlling the motor 6. The controller 13 includes: a substrate is mounted with a plurality of electronic components. Examples of the electronic component mounted on the substrate include: a processor such as a cpu (central Processing unit), a nonvolatile memory such as a rom (read Only memory) or a memory, a volatile memory such as a ram (random Access memory), a transistor, and a resistor.

At least a part of the controller 13 is housed in the controller case 62. The controller case 62 is disposed in the internal space of the controller housing portion 23. At least a part of the controller 13 is housed in the controller case 62.

The controller 13 switches the control mode of the motor 6 based on the operation content of the electric power tool 1. The control mode of the motor 6 is: control method or control form of the motor 6.

The trigger switch 14 is provided on the grip portion 22. The trigger switch 14 is operated by the operator to activate the motor 6. The trigger switch 14 includes: a trigger part 14A, and a switch circuit 14B. The switch circuit 14B is housed in the grip portion 22. The trigger member 14A protrudes forward from the upper portion of the front portion of the grip portion 22. The trigger member 14A is operated by an operator. By operating the trigger 14A, the driving and stopping of the motor 6 can be switched.

The forward/reverse switching lever 15 is provided above the grip 22. The forward/reverse switching lever 15 is operated by an operator. By operating the forward/reverse switching lever 15, the rotation direction of the motor 6 can be switched from one of the forward rotation direction and the reverse rotation direction to the other. By switching the rotation direction of the motor 6, the rotation direction of the main shaft 8 can be switched.

The operation panel 16 is provided in the controller housing portion 23. The operation panel 16 is operated by an operator to switch the control mode of the motor 6. The operation panel 16 has a plate shape. The controller housing section 23 includes: for configuring the opening 63 of the operation panel 16. The opening 63 is provided on the upper surface of the controller housing portion 23 at a position forward of the grip portion 22. At least a part of the operation panel 16 is disposed in the opening 63. The operation panel 16 has a plurality of operation switches 64. By operating the operation switch 64, the control mode of the motor 6 can be switched.

The mode changeover switch 17 is provided above the trigger member 14A. The mode changeover switch 17 is operated by an operator. By operating the mode switching switch 17, the control mode of the motor 6 can be switched.

The lamps 18 are respectively disposed at: the left and right portions of the motor housing portion 21. The lamp 18 emits: for illuminating the illumination light in front of the power tool 1. The lamp 18 comprises, for example, a Light Emitting Diode (LED).

< actions of electric tool >

Next, the operation of the electric power tool 1 will be described. For example, when a screw fastening work is performed on a work object, the tip tool BT used in the screw fastening work is inserted into the insertion hole 55 of the anvil 10. The leading end tool BT inserted into the insertion hole 55 is held by the tool holding device 11A. After the tool bit is attached to the anvil 10, the operator holds the grip portion 22 and operates the trigger switch 14. Upon operation of the trigger switch 14, power is supplied from the battery pack 25 to the motor 6, so that the motor 6 is started. By the start of the motor 6, the rotor shaft 32 rotates. When the rotor shaft 32 rotates, the rotational force of the rotor shaft 32 is transmitted to the planetary gear 42 via the pinion gear 41. The planetary gear 42 revolves around the pinion gear 41 while rotating on its axis in a state of meshing with the internal teeth of the internal gear 43. The planetary gear 42 is rotatably supported by the main shaft 8 via a pin. The revolution of the planetary gear 42 causes the main shaft 8 to rotate at a rotational speed lower than the rotational speed of the rotor shaft 32.

In a state where the hammer protrusion 47B is in contact with the anvil protrusion 10B, if the main shaft 8 rotates, the anvil 10 rotates together with the hammer 47 and the main shaft 8. By the rotation of the anvil 10, the screw fastening work is performed.

When a load of a predetermined value or more acts on the anvil 10 as the screw fastening operation proceeds, the rotation of the anvil 10 and the hammer 47 is stopped. In a state where the hammer 47 stops rotating, if the main shaft 8 rotates, the hammer 47 moves rearward. By moving the hammer 47 rearward, the contact between the hammer protrusion 47B and the anvil protrusion 10B is released. The hammer 47 moved to the rear moves forward while rotating by the elastic force of the coil spring 49. When the hammer 47 moves forward while rotating, the anvil 10 is struck by the hammer 47 in the rotating direction. Accordingly, the anvil 10 rotates around the rotation axis AX with a high torque. Accordingly, the screw can be fastened to the work object with a high torque.

< tool holding device >

Fig. 5 is a transverse cross-sectional view showing the tool holder 11A according to the present embodiment. Fig. 6 is a longitudinal sectional view showing a tool holder 11A according to the present embodiment. Fig. 7 is a sectional view showing a tool holder 11A according to the present embodiment. Fig. 7 corresponds to a sectional view taken along line a-a of fig. 5. Fig. 8 and 9 are enlarged cross-sectional views of a part of a tool holding device 11A according to the present embodiment, respectively. Fig. 8 shows a state where the tip tool BT has not been inserted into the insertion hole 55. Fig. 9 corresponds to an enlarged view of a part of fig. 8.

The tool holding device 11A holds the tip tool BT inserted into the insertion hole 55 of the anvil 10. The tool holding device 11A can attach and detach the tip tool BT. As shown in fig. 5, 6, and 7, the tool holding device 11A includes: a locking member 71, a 1 st elastic member 72, a sleeve 73, a 2 nd elastic member 74, and a positioning member 75.

The tip tool BT has: the fitting portion B1, a groove portion B2 provided on the side surface of the fitting portion B1, a tapered portion B3 provided at the rear end portion of the fitting portion B1, and a processed portion B4 provided at the front end portion of the fitting portion B1 (see fig. 4).

The anvil 10 has: a rod-shaped anvil body 10A, and an anvil protrusion 10B provided at the rear portion of the anvil body 10A. The insertion hole 55 is provided in the anvil body 10A. The insertion hole 55 extends in the axial direction. The anvil projections 10B are provided in 2 numbers. The anvil projection 10B projects from the rear portion of the anvil body 10A toward the radially outer side.

An opening 55A is provided at the tip of the insertion hole 55. A bottom surface 55B is provided at the rear end of the insertion hole 55. The tip tool BT is inserted into the insertion hole 55 from the opening 55A. In a state where at least a part of the tip tool BT is disposed in the opening 55A, the tip tool BT is inserted into the insertion hole 55 by moving the tip tool BT rearward.

In a cross section orthogonal to the rotation axis AX, the fitting portion B1 has a substantially hexagonal outer shape. The insertion hole 55 has a substantially hexagonal shape in a cross section orthogonal to the rotation axis AX.

The anvil 10 has: a support recess 82 for supporting the lock member 71. The support concave portion 82 is formed in: the outer surface of the anvil body 10A. A support recess 82 is formed in an intermediate portion of the anvil body 10A in the axial direction. The support recess 82 is long in the axial direction. The anvil body 10A includes: and a through hole 81 for connecting an inner surface of the support recess 82 and an inner surface of the insertion hole 55. As described above, the insertion hole 55 has a substantially hexagonal shape in a cross section orthogonal to the rotation axis AX. The support recess 82 is connected to a corner of the insertion hole 55 via the through hole 81. The support recess 82 is formed in plurality in the circumferential direction. The plurality of support recesses 82 are formed at equal intervals in the circumferential direction. In the present embodiment, 2 support concave portions 82 are formed.

The lock member 71 is movably supported by the anvil 10. The locking member 71 locks the tip tool BT inserted into the insertion hole 55. The lock member 71 is made of metal. The locking member 71 is a spherical member. In the following description, the locking member 71 is appropriately referred to as a ball 71.

The balls 71 are supported by the support concave portions 82. The balls 71 are disposed in the plurality of support recesses 82 in 1 number, respectively. In the present embodiment, the tool holding device 11A has 2 balls 71. The number of balls 71 is 2 around the anvil body 10A.

The diameter of the ball 71 is larger than that of the through hole 81. In a state where the balls 71 are supported by the support concave portions 82, at least a part of the balls 71 is disposed inside the insertion holes 55 through the through holes 81. That is, in a state where the ball 71 is supported by the support concave portion 82, at least a part of the ball 71 is arranged: projects from the through hole 81 toward the inside of the insertion hole 55.

The balls 71 are movable in the axial direction and the radial direction in a state of being in contact with the inner surface of the support concave portion 82. The ball 71 is movable between a lock position for locking the tool bit BT and an unlock position for unlocking the tool bit BT.

As described above, at least a part of the ball 71 is disposed inside the insertion hole 55 through the through hole 81. The side surface of the tip tool BT is provided with a groove portion B2. At least a part of the tip tool BT including the groove portion B2 is inserted into the insertion hole 55. The tip tool BT is locked by at least a part of the ball 71 being disposed in the groove portion B2 of the tip tool BT. By disposing at least a part of the ball 71 in the groove portion B2, the tip tool BT can be positioned in each of the axial direction, the radial direction, and the circumferential direction. The locking positions of the balls 71 include: at least a part of the ball 71 is disposed at the position of the groove B2 of the tool bit BT. The release position of the ball 71 includes: the ball 71 is disposed outside the groove B2 of the tool bit BT.

The 1 st elastic member 72 produces: and a spring force that moves the ball 71 toward the lock position. In the present embodiment, the 1 st elastic member 72 is a compression coil spring. The 1 st elastic member 72 is disposed around the anvil body 10A. In the present embodiment, the 1 st elastic member 72 generates: and a spring force for moving the ball 71 forward.

The sleeve 73 is a cylindrical member. The sleeve 73 is disposed: around the anvil body 10A. The sleeve 73 is movable in the axial direction around the anvil body 10A. The sleeve 73 can prevent: the balls 71 arranged in the locking position are disengaged from the locking position. The sleeve 73 can change the balls 71 into: a state in which the lock member can be moved from the lock position to the release position.

The sleeve 73 is movable around the anvil body 10A between a blocking position for blocking the movement of the balls 71 radially outward and an allowing position for allowing the movement of the balls 71 radially outward.

By disposing the sleeve 73 at the blocking position, it is possible to suppress: the balls 71 arranged in the locking position move radially outward. That is, by disposing the sleeve 73 at the blocking position, it is possible to block: the balls 71 arranged in the locking position are disengaged from the locking position. By the sleeve 73 being arranged at the blocking position, it is possible to maintain: the state in which the tip tool BT is locked by the ball 71.

By moving the sleeve 73 towards the allowed position, it is allowed: the balls 71 disposed in the locking position move radially outward. The sleeve 73 moves toward the permission position, and the balls 71 change to: a state in which the lock member can move from the lock position to the release position. That is, by the sleeve 73 being arranged at the allowing position, it is allowed to: the balls 71 arranged in the locking position are disengaged from the locking position. By disposing the sleeve 73 at the permission position, it is possible to cancel: the state in which the tip tool BT is locked by the ball 71.

The 2 nd elastic member 74 generates an elastic force to move the sleeve 73 toward the blocking position. In the present embodiment, the 2 nd elastic member 74 is a compression coil spring. The 2 nd elastic member 74 is disposed: around the anvil body 10A. The blocking position is defined as: further to the rear than the allowable position. The 2 nd elastic member 74 produces: and a spring force for moving the sleeve 73 rearward.

The positioning member 75 is: and a ring-shaped member fixed to an outer surface of the anvil body 10A. The positioning member 75 is fixed to: can be positioned to face the rear end portion of the sleeve 73. The positioning member 75 is used to position the sleeve 73 in the blocking position. The sleeve 73, to which the elastic force moving rearward is applied from the 2 nd elastic member 74, is positioned at the stopping position by being in contact with the positioning member 75.

A 1 st recess 94 is formed in the outer surface of the anvil body 10A. The 1 st recess 94 is provided with: and a position further to the rear than the support recess 82. The 1 st recess 94 is formed: surrounding the rotation axis AX. At least a part of the positioning member 75 is disposed in the 1 st recess 94. Since a part of the positioning member 75 including the inner end portion of the positioning member 75 is disposed in the 1 st recess 94, the positioning member 75 is fixed to the anvil body 10A.

The 2 nd recess 91 is provided at the rear end of the sleeve 73. At least a part of the surface of the positioning member 75 is in contact with the inner surface of the 2 nd recess 91. The sleeve 73 is positioned in the blocking position by at least a part of the surface of the positioning member 75 contacting the inner surface of the 2 nd recess 91 of the sleeve 73.

The sleeve 73 has: a cylindrical sleeve body 73A; a protrusion 88 protruding radially inward from the inner surface of the sleeve main body 73A and capable of coming into contact with the anvil main body 10A; a 1 st groove 80 provided at a position rearward of the projection 88 and facing the anvil body 10A; and a 2 nd groove 87 provided at a position forward of the projection 88 and facing the anvil body 10A. The protrusion 88 can be in contact with not only the anvil body 10A but also the ball 71. The 1 st elastic member 72 is disposed inside the 1 st groove 80. The 2 nd elastic member 74 is disposed inside the 2 nd groove 87.

The protrusion 88 is disposed: is located further forward than the 1 st elastic member 72. The projection 88 extends radially inward from the inner surface of the sleeve main body 73A. The projection 88 is annular.

As shown in fig. 8 and 9, the protrusion 88 includes: a forward facing front surface 88T, a rearward facing inclined surface 95, and a radially inwardly facing inner surface 88S. The inner surface 88S of the protrusion 88 is contactable with the outer surface 10S of the anvil body 10A. The inner surface 88S of the projection 88 can be in contact with the ball 71.

As shown in fig. 5 and 6, a 3 rd recess 96 is formed in the outer surface of the anvil body 10A. The 3 rd recess 96 is provided with: is positioned further forward than the support recess 82. The 3 rd recess 96 is formed: surrounding the rotation axis AX.

At least a part of the stopper ring 92 is disposed in the 3 rd recess 96. A stopper 93 is disposed rearward of the stopper ring 92. The stopper 93 is an annular member. The stop 93 is positioned by the stop ring 92.

The 2 nd elastic member 74 is configured to: the rear end portion of the 2 nd elastic member 74 contacts the front surface 88T of the projection 88, and the front end portion of the 2 nd elastic member 74 contacts the stopper 93. The front end of the 2 nd elastic member 74 is connected to the anvil body 10A via the stopper 93 and the stopper ring 92, and the rear end of the 2 nd elastic member 74 is in contact with the projection 88 of the sleeve 73, so that the 2 nd elastic member 74 can generate: and a spring force for moving the sleeve 73 rearward.

The anvil 10 has: a 3 rd groove 83 formed on the outer surface of the anvil body 10A. The 3 rd slot 83 is provided: facing the sleeve 73. At least a part of the 3 rd groove 83 is provided with: and a position further to the rear than the support recess 82.

At least a part of the 1 st elastic member 72 is disposed around the anvil main body 10A so as to face the support concave portion 82. The 1 st elastic member 72 is disposed: the 3 rd slot 83.

As shown in fig. 9, the 3 rd groove 83 has: a bottom portion 84, a wall portion 85 provided at a rear position of the bottom portion 84, and a tapered portion 86 provided at a front position of the bottom portion 84.

The diameter of the bottom portion 84 may be smaller than the diameter of the anvil body 10A. The diameter of the bottom 84 may be equal in the circumferential direction as well as in the axial direction, respectively.

Wall portion 85 is provided at: the rear position of the bottom 84. Wall portion 85 is configured to: surrounding the rotation axis AX. The wall portion 85 is provided as: orthogonal to a line parallel to the rotation axis AX.

The tapered portion 86 is inclined radially outward as it goes forward. The rear end of the tapered portion 86 is smoothly connected to the bottom portion 84. The front end of the tapered portion 86 is smoothly connected to the outer surface 10S of the anvil body 10A. In a cross section including the rotation axis AX, a boundary between the tapered portion 86 and the bottom portion 84 is curved, and a boundary between the tapered portion 86 and the outer surface 10S of the anvil 10 is curved. The tapered portion 86 may be linear or curved in a cross section parallel to the rotation axis AX.

The 1 st elastic member 72 is configured to: the front end of the 1 st elastic member 72 is in contact with the ball 71, and the rear end of the 1 st elastic member 72 is in contact with at least a portion of the anvil 10. In the present embodiment, the rear end portion of the 1 st elastic member 72 is in contact with the wall portion 85 provided at a position rearward of the support concave portion 82.

The rear end portion of the 1 st elastic member 72 is in contact with the wall portion 85 of the anvil body 10A, and the front end portion of the 1 st elastic member 72 is in contact with the ball 71, so that the 1 st elastic member 72 can generate: and a spring force for moving the ball 71 forward.

The inclined surface 95 is provided in the axial direction: between the projection 88 and the 1 st slot 80. The inclined surface 95 contacts the ball 71 moving outward in the radial direction. The sleeve 73 can move forward by the contact between the balls 71 and the inclined surface 95. That is, the sleeve 73 can be moved toward the permission position by the contact between the balls 71 and the inclined surface 95.

The balls 71 moving radially outward contact the inclined surface 95, and the sleeve 73 can move forward against the elastic force of the 2 nd elastic member 74. The inclined surface 95 is inclined rearward as going to the radially outer side. An angle θ formed by a line parallel to the rotation axis AX of the anvil 10 and the inclined surface 95 is larger than 45 ° and smaller than 90 °.

The 1 st slot 80 includes: part 1 89 and part 2 90. The 1 st and 2

nd portions

89 and 90 are arranged in the axial direction. The 1 st part 89 is joined to the 2 nd part 90. The 2 nd portion 90 is configured to: more rearward than the 1 st portion 89. The 2 nd recess 91 is provided with: the rear end of the 2 nd portion 90.

In this embodiment, the inner diameter of the 1 st portion 89 is equal to the inner diameter of the 2 nd portion 90. Further, the inner diameter of the 1 st portion 89 may be different from the inner diameter of the 2 nd portion 90.

Radially, the outer surface of the anvil body 10A is spaced apart from the rear end of the 1 st slot 80. An opening is provided at the rear end of the 1 st groove 80.

Part

1, 89 allows: the balls 71 move radially outward. At least a part of the balls 71 moving outward in the radial direction is disposed in the 1 st portion 89. The 2 nd portion 90 houses the 1 st elastic member 72 in a compressed state. At least a portion of the 1 st elastic member 72 is disposed at the 2 nd portion 90.

As described above, the sleeve 73 is movable between the blocking position for blocking the movement of the balls 71 radially outward and the allowing position for allowing the movement of the balls 71 radially outward. The blocking positions are: the projection 88 is disposed at a position radially outward of the ball 71. The allowed positions are: the projection 88 is disposed further forward than the ball 71 and the 1 st portion 89 is disposed radially outward of the ball 71.

As shown in fig. 8, the winding diameter Da of the 1 st elastic member 72 is larger than the inner diameter Dc of the insertion hole 55. In a state where the tip tool BT is not inserted into the insertion hole 55, the winding diameter Da of the 1 st elastic member 72 is equal to the distance Db between the outer end of one of the balls 71 and the outer end of the other ball 71, or the winding diameter Da is larger than the distance Db.

As shown in FIG. 9, the inner diameter Dt of the inner surface 88S of the projection 88 is slightly larger than the outer diameter Ds of the outer surface 10S of the anvil 10. The inner surface 88S of the projection 88 contacts the outer surface 10S of the anvil 10, and guides the anvil 10 in the front-rear direction. The inner surface 88S functions as a positioning portion of the sleeve 73 in the radial direction with respect to the anvil 10. The inner surface 88S functions as a bearing portion for the anvil 10. The inner surface 88S is disposed forward of the 1 st elastic member 72 and rearward of the 2 nd elastic member 74. The inner surface 88S is disposed at an intermediate position of the sleeve 73 in the front-rear direction, and therefore, a positioning function can be sufficiently exhibited.

< positioning component >

Fig. 10 is a perspective view showing the positioning member 75 according to the present embodiment. The positioning member 75 is annular. The positioning member 75 includes an annular spring. As shown in fig. 5 to 9, the positioning member 75 is disposed: and a position further to the rear than the support recess 82. At least a part of the positioning member 75 is disposed in the 1 st recess 94, and the positioning member 75 is fixed to the anvil body 10A.

The rear end of the sleeve 73 is in contact with the positioning member 75. In a cross section parallel to the rotation axis AX, a contact surface 75S of the positioning member 75 that contacts the sleeve 73 is a curved surface.

In the present embodiment, the positioning member 75 has a circular outer shape in a cross section parallel to the rotation axis AX.

The 2 nd recess 91 is provided at the rear end of the sleeve 73. The contact surface 75S of the positioning member 75 contacts the inner surface of the 2 nd recess 91. In a cross section parallel to the rotation axis AX, the inner surface of the 2 nd recess 91 has an arc shape. Since the inner surface of the 2 nd recessed portion 91 has an arc shape in a cross section parallel to the rotation axis AX, the contact surface 75S of the positioning member 75 can sufficiently contact the inner surface of the 2 nd recessed portion 91.

As shown in fig. 9, in a cross section parallel to the rotation axis AX, the depth Ra of the 1 st recess 94 is the same as the radius Rb of the positioning member 75. Since the depth Ra of the 1 st recessed portion 94 is equal to the radius Rb of the positioning member 75, the positioning member 75 can be sufficiently fitted into the 1 st recessed portion 94.

Further, in a cross section parallel to the rotation axis AX, the depth Ra of the 1 st recess 94 may be larger than the radius Rb of the positioning member 75. Even when the depth Ra of the 1 st recessed portion 94 is larger than the radius Rb of the positioning member 75, the positioning member 75 can be sufficiently fitted into the 1 st recessed portion 94.

< actions when mounting a front tool to an anvil >

Next, an operation when the tool bit BT is attached to the anvil 10 will be described. Fig. 11 to 17 are sectional views each showing an operation when the tool bit BT according to the present embodiment is attached to the anvil 10.

With reference to fig. 11 to 16, the operation of attaching the tool bit BT to the anvil 10 in a state where the sleeve 73 is not operated will be described.

As shown in fig. 11, in a state before the tip tool BT is assembled to the anvil 10, the sleeve 73 is moved rearward by the elastic force of the 2 nd elastic member 74. The 2 nd elastic member 74 generates an elastic force to move the sleeve 73 toward the blocking position. The rear end of the sleeve 73 is in contact with the positioning member 75. The positioning member 75 positions the sleeve 73 in the blocking position.

The projection 88 is disposed at a position radially outside the ball 71 in a state where the sleeve 73 is disposed at the blocking position. Since the projection 88 is disposed at a position radially outside the ball 71, it is possible to prevent: the balls 71 move radially outward.

As shown in fig. 12, when the insertion of the nose tool BT with respect to the insertion hole 55 is started, the tapered portion B3 of the nose tool BT comes into contact with the ball 71. The ball 71 moves rearward inside the support concave portion 82 by contact with the tapered portion B3.

As shown in fig. 13, when the front end tool BT is further moved toward the rear, the ball 71 is moved toward the radially outer side by contact with the tapered portion B3. The balls 71 are moved radially outward to contact the 1 st elastic member 72.

As shown in fig. 14, when the front end tool BT is further moved toward the rear, the ball 71 comes into contact with the fitting portion B1. The ball 71 is further moved toward the radially outer side by the contact with the fitting portion B1. When the balls 71 move radially outward, the 1 st elastic member 72 is deformed by contact with the balls 71. The 1 st elastic member 72 is compressed. The 1 st elastic member 72 is deformed so that the winding diameter Da becomes larger.

As shown in fig. 14, when the ball 71 moves radially outward, at least a part of the surface of the ball 71 comes into contact with the inclined surface 95 of the protrusion 88. The sleeve 73 moves forward by the contact between the balls 71 and the inclined surface 95. That is, the sleeve 73 is moved toward the permission position by the contact between the balls 71 moving toward the radial outside and the inclined surface 95.

As shown in fig. 15, when the sleeve 73 is arranged at the permission position, the balls 71 can move radially outward. At least a part of the balls 71 is disposed: portion 1 89 of slot 1 80. The release position of the ball 71 includes: at least a part of the ball 71 is disposed at the position of the 1 st portion 89. In a state where at least a part of the balls 71 is disposed in the 1 st portion 89, the 1 st elastic member 72 is disposed in a compressed state in the 2 nd portion 90 of the 1 st groove 80.

When the ball 71 moves radially outward and is disposed at the release position, the tool bit BT can be smoothly inserted into the insertion hole 55. The tip tool BT can move rearward while bringing the outer surface of the mounting portion B1 into contact with the surface of the ball 71.

As shown in fig. 16, when the front end tool BT is further moved rearward so that the groove portion B2 is disposed at a position radially inward of the ball 71, the 1 st elastic member 72 generates an elastic force that moves the ball 71 toward the lock position. The balls 71 move forward inside the support concave 82 by the elastic force of the 1 st elastic member 72. At least a part of the ball 71 moving forward inside the support recess 82 is disposed inside the insertion hole 55 through the through hole 81. At least a part of the ball 71 is disposed inside the groove B2. At least a part of the ball 71 is supported by the support concave 82. The locking positions of the balls 71 include: at least a part of the ball 71 is disposed at the position of the groove portion B2. With the balls 71 arranged in the locked position, the tip tool BT is locked. The tool bit BT is fixed to the anvil body 10A by a ball 71.

When the balls 71 are disposed in the locked position, the sleeve 73 is moved rearward by the elastic force of the 2 nd elastic member 74. The sleeve 73 moved to the rear is brought into contact with the positioning member 75 and positioned at the blocking position. The projection 88 is disposed at a position radially outside the ball 71 in a state where the sleeve 73 is disposed at the blocking position. In a state where the ball 71 is arranged in the lock position, the inner surface 88S of the protrusion 88 contacts at least a part of the surface of the ball 71. By the contact between the protrusion 88 and the ball 71, it is possible to prevent: the balls 71 move radially outward. Since the movement of the ball 71 can be prevented, it is possible to maintain: the state in which the tip tool BT is locked by the ball 71.

As described with reference to fig. 11 to 16, when the tip tool BT is inserted into the insertion hole 55 without operating the sleeve 73, the 1 st elastic member 72 is elastically deformed, and the balls 71 can be automatically fitted into the groove portions B2 of the tip tool BT. Further, after the balls 71 are automatically fitted into the groove portions B2, the winding diameter Da of the 1 st elastic member 72 is reduced. The rolling ball 71 is abruptly moved toward the groove portion B2 by the winding diameter Da of the 1 st elastic member 72 being abruptly decreased. When the balls 71 move toward the groove B2, the balls 71 collide with the inner surface of the groove B2 to generate sound. Accordingly, the operator can recognize that: the front end tool BT has been fixed to the anvil 10.

Next, with reference to fig. 17, description will be made of: the operation when the tool bit BT is attached to the anvil 10 in a state where the sleeve 73 is moved forward by being operated.

As shown in fig. 17, when the worker operates the sleeve 73 so as to move forward and is arranged at the allowable position, the projection 88 is arranged: the 1 st portion 89 of the 1 st groove 80 is disposed further forward than the ball 71: the radially outer position of the balls 71.

In a state where the 1 st portion 89 is arranged at a position radially outside the ball 71, if the tip tool BT is inserted into the insertion hole 55, the tapered portion B3 of the tip tool BT comes into contact with the ball 71. The ball 71 moves rearward inside the support concave portion 82 by contact with the tapered portion B3.

When the front end tool BT is further moved rearward, the ball 71 is moved radially outward by contact with the tapered portion B3. The balls 71 are moved radially outward to contact the 1 st elastic member 72.

When the front end tool BT is further moved toward the rear, the ball 71 comes into contact with the fitting portion B1. The ball 71 is further moved toward the radially outer side by the contact with the fitting portion B1. When the balls 71 move radially outward, the 1 st elastic member 72 is deformed by contact with the balls 71. The 1 st elastic member 72 is compressed. The 1 st elastic member 72 is deformed so that the winding diameter Da becomes larger. The 1 st elastic member 72 is disposed in a compressed state in the 2 nd portion 90 of the 1 st groove 80.

In a state where the 1 st elastic member 72 is disposed in the 2 nd portion 90, if the balls 71 move radially outward, at least a part of the balls 71 is disposed in the 1 st portion 89 of the 1 st groove 80. In the state where the 2 nd elastic member 74 is disposed in the 2 nd portion 90, the balls 71 can move radially outward, and therefore, at least a part of the balls 71 is smoothly disposed in the 1 st portion 89.

When the ball 71 moves radially outward and is disposed at the release position, the tool bit BT can be smoothly inserted into the insertion hole 55. The tip tool BT can move rearward while bringing the outer surface of the mounting portion B1 into contact with at least a part of the surface of the ball 71.

When the front end tool BT is further moved rearward so that the groove portion B2 is disposed at a position radially inward of the ball 71, the 1 st elastic member 72 generates an elastic force that moves the ball 71 toward the lock position. The balls 71 move forward inside the support concave 82 by the elastic force of the 1 st elastic member 72. At least a part of the ball 71 moving forward inside the support recess 82 is disposed inside the insertion hole 55 through the through hole 81. At least a part of the ball 71 is disposed inside the groove B2. With the balls 71 arranged in the locked position, the tip tool BT is locked. The tool bit BT is fixed to the anvil body 10A by a ball 71.

After the balls 71 are placed in the locked position, when the operation of the sleeve 73 is released, the sleeve 73 is moved rearward by the elastic force of the 2 nd elastic member 74. The sleeve 73 moved to the rear is brought into contact with the positioning member 75 and positioned at the blocking position. The projection 88 is disposed at a position radially outside the ball 71 in a state where the sleeve 73 is disposed at the blocking position. In a state where the ball 71 is arranged in the lock position, the inner surface 88S of the protrusion 88 contacts at least a part of the surface of the ball 71. By the contact between the protrusion 88 and the ball 71, it is possible to prevent: the balls 71 move radially outward. Since the movement of the ball 71 can be prevented, it is possible to maintain: the state in which the tip tool BT is locked by the ball 71.

In this way, even when the tool bit BT is inserted into the insertion hole 55 in a state where the sleeve 73 is moved forward by being operated, the balls 71 can be automatically placed in the locking position by elastic deformation of the 1 st elastic member 72.

< action when removing front end tool from anvil >

Next, an operation when the tip tool BT is detached from the anvil 10 will be described. Fig. 18 to 21 are cross-sectional views each showing an operation when the tool bit BT according to the present embodiment is detached from the anvil 10.

Fig. 18 shows a state in which the tool bit BT is fixed to the anvil 10 by the ball 71. As shown in fig. 18, at least a part of the ball 71 is disposed inside the groove portion B2, and the ball 71 is disposed in the locked position, whereby the tool bit BT is fixed to the anvil 10 via the ball 71. In a state where the balls 71 are arranged at the lock position, the sleeve 73 is arranged at the blocking position. When the sleeve 73 is disposed at the blocking position and the projection 88 is disposed at the position radially outside the ball 71, it is possible to block: the balls 71 move radially outward, and thus: the balls 71 are arranged in the locked position. In addition, the 2 nd elastic member 74 generates: and a spring force for moving the sleeve 73 rearward. The sleeve 73 is positioned in the blocking position by means of the positioning member 75.

As shown in fig. 19, the operator moves the tip tool BT forward to detach the tip tool BT from the anvil 10. When the tip tool BT moves forward, the ball 71 moves radially outward due to contact with the tip tool BT.

As shown in fig. 20, the sleeve 73 is operated so as to be moved toward the front. When the sleeve 73 is moved forward and is disposed at the permission position, the 1 st portion 89 is disposed at a position radially outside the balls 71. In a state where the 1 st portion 89 is arranged at a position radially outward of the ball 71, the ball 71 is moved radially outward while contacting the surface of the fitting portion B1 by further moving the tip tool BT forward. At least a part of the balls 71 moved to the radially outer position is disposed in the 1 st portion 89.

The ball 71 moves radially outward and is disposed at the release position, so that the tool bit BT can move smoothly. The tip tool BT moves forward while bringing the outer surface of the fitting portion B1 into contact with at least a part of the surface of the ball 71.

As shown in fig. 21, in a state where the balls 71 are disposed at the release position, the tool bit BT is moved forward, and the tool bit BT is pulled out from the insertion hole 55. The front end tool BT is detached from the anvil 10.

< Effect >

As described above, according to the present embodiment, the contact surface 75S of the positioning member 75 that contacts the sleeve 73 is a curved surface in the cross section parallel to the rotation axis AX. Accordingly, the contact area between the positioning member 75 and the sleeve 73 becomes large. Therefore, it is possible to suppress: deterioration of the contact surface 75S of the positioning member 75 due to wear. Likewise, it is possible to suppress: deterioration of the sleeve 73 due to wear. Since the durability of the positioning member 75 and the sleeve 73 is improved, the operator can use the tool holding device 11A with good operability. Therefore, the operability of the electric power tool 1 is improved, and it is possible to suppress: the reduction in the work efficiency of the operator.

In the present embodiment, the positioning member 75 includes an annular spring. The positioning member 75 has a circular outer shape in a cross section parallel to the rotation axis AX. Accordingly, the durability of the positioning member 75 is improved.

At least a part of the positioning member 75 is disposed: a 1 st recess 94 formed in the outer surface 10S of the anvil body 10A. The depth Ra of the 1 st recess 94 is equal to or greater than the radius Rb of the positioning member 75. Since the depth Ra is equal to or larger than the radius Rb, the positioning member 75 can be sufficiently fitted in the 1 st recess 94. Therefore, the positioning member 75 is sufficiently fixed to the anvil body 10A.

The 2 nd recess 91 is provided at the rear end of the sleeve 73. The sleeve 73 is positioned at the blocking position by the contact surface 75S of the positioning member 75 contacting the inner surface of the 2 nd recess 91. The contact between the positioning member 75 and the sleeve 73 is stabilized by the 2 nd recessed portion 91. Further, since the positioning member 75 is disposed at the position inside the 2 nd recessed portion 91, the positioning member 75 is hidden by the sleeve 73 in the state where the sleeve 73 is disposed at the blocking position. Accordingly, the appearance quality of the electric power tool 1 is improved.

The balls 71 are supported by: and a support recess 82 formed in the outer surface 10S of the anvil body 10A. Is formed with: and a through hole 81 for connecting an inner surface of the support recess 82 and an inner surface of the insertion hole 55. The balls 71 can move between the locked position and the released position by moving inside the support concave 82. With the balls 71 arranged in the locked position, the tip tool BT is sufficiently positioned. With the tip tool BT sufficiently positioned, the operability of the electric power tool 1 becomes good.

The sleeve 73 has: a protrusion 88, a 1 st groove 80, and a 2 nd groove 87. By the inner surface 88S of the protrusion 88 being in contact with the outer surface 10S of the anvil body 10A, the outer diameter Ds of the anvil body 10A at the outer surface 10S can be increased. Accordingly, it is possible to suppress: cracks appear on the anvil 10, whereby: the durability of the anvil 10 is reduced. Further, the 1 st elastic member 72 is disposed at a position inside the 1 st groove 80, and the 2 nd elastic member 74 is disposed in the 2 nd groove 87, whereby: the tool holding device 11A is large.

In addition, the projection 88 of the sleeve 73 can contact the ball 71. The operation of the balls 71 is stabilized by the contact of the protrusions 88 of the sleeve 73 with the balls 71.

The 1 st groove 80 of the sleeve 73 has: a 1 st portion 89 for disposing at least a part of the balls 71 moving radially outward; and a 2 nd portion 90 connected to the 1 st portion 89 and configured to dispose the 1 st elastic member 72 in a compressed state. As described with reference to fig. 17, when the tip tool BT is inserted into the insertion hole 55 in the state where the sleeve 73 is arranged at the allowable position, the 1 st elastic member 72 is compressed by the balls 71 that move radially outward by contact with the tapered portion B3, and the 1 st elastic member 72 after being compressed is arranged at the 2 nd part 90. Since the 1 st elastic member 72 is disposed in the 2 nd portion 90, the balls 71 can smoothly move toward the 1 st portion 89. Thus, the tip tool BT is inserted into the insertion hole 55 with good operability.

A 3 rd groove 83 is provided on the outer surface of the anvil body 10A. The 1 st elastic member 72 is disposed in the 3 rd groove 83. The 3 rd groove 83 has: a bottom portion 84; a wall portion 85 provided behind the bottom portion 84 and in contact with the 1 st elastic member 72; and a tapered portion 86 provided forward of the bottom portion 84 and inclined radially outward as it goes forward. The rear end of the 1 st elastic member 72 is supported by the wall portion 85. By providing the tapered portion 86, it is possible to suppress: stress concentration in the 3 rd slot 83. Since the stress concentration in the 3 rd groove 83 can be suppressed, it is possible to suppress: the durability of the anvil 10 is reduced.

The front end of the 1 st elastic member 72 is in contact with the ball 71, and the rear end of the 1 st elastic member 72 is in contact with at least a portion of the anvil 10. The 1 st elastic member 72 can generate: and a spring force that moves the ball 71 toward the lock position.

The sleeve 73 has: and an inclined surface 95 which comes into contact with the ball 71 moving radially outward. When the leading end tool BT is inserted into the insertion hole 55 and the ball 71 is moved toward the radially outer side, the sleeve 73 can be automatically moved toward the allowance position by the contact between the surface of the ball 71 and the inclined surface 95. An angle θ formed by a line parallel to the rotation axis AX and the inclined surface 95 is greater than 45 ° and smaller than 90 °. By setting the angle θ of the inclined surface 95 to an appropriate angle, the sleeve 73 can be smoothly moved toward the allowable position with a small force.

Further, the worker can obtain a click feeling by inserting the tip tool BT into the insertion hole 55 and bringing the ball 71 into contact with the inclined surface 95.

When the tip tool BT is inserted into the insertion hole 55 and the ball 71 moves radially outward, the 1 st elastic member 72 is elastically deformed by contact with the ball 71. The 1 st elastic member 72 is elastically deformed so that the winding diameter Da becomes larger. For example, the winding diameter Da of the 1 st elastic member 72 in the state shown in fig. 14 is larger than the winding diameter Da of the 1 st elastic member 72 in the state shown in fig. 16. Accordingly, the operation of the balls 71 is stabilized.

[ 2 nd embodiment ]

Embodiment 2 will be explained. In the following description, the same or equivalent constituent elements as those of the above-described embodiment are given the same reference numerals, and the description thereof will be omitted or simplified.

Fig. 22 is an enlarged transverse cross-sectional view of the upper portion of the electric power tool 1 according to the present embodiment. Fig. 23 is a transverse cross-sectional view showing a tool holder 11B according to the present embodiment. Fig. 24 is a sectional view showing a tool holder 11B according to the present embodiment.

As in the above-described embodiment, the tool holding device 11B includes: a ball 71 movable between a lock position and a release position; a 1 st elastic member 72 that generates an elastic force to move the ball 71 toward the lock position; a sleeve 73 that is movable between a blocking position that blocks movement of the balls 71 radially outward and an allowing position that allows movement of the balls 71 radially outward; a 2 nd elastic member 74 generating an elastic force to move the sleeve 73 toward the blocking position; and a positioning member 75 that positions the sleeve 73 in the blocking position.

In the present embodiment, 3 support recesses 82 are provided around the rotation axis AX. The balls 71 are disposed in 1 in each of the 3 support concave portions 82. The balls 71 are provided in 3 numbers around the anvil body 10A. The 3 balls 71 are arranged at equal intervals in the rotation direction. The tip tool BT is fixed to the anvil body 10A by 3 balls 71.

The 3 balls 71 are movable between the lock position and the release position, respectively. At least a part of the ball 71 is disposed in the groove portion BT of the tool bit BT through the through hole 81, and the tool bit BT is locked. As in the above-described embodiment, the lock position of the ball 71 includes: at least a part of the ball 71 is disposed at the position of the groove B2 of the tool bit BT.

As described above, the balls 71 are provided in 3 numbers, so that the tip tool BT can be appropriately positioned at the anvil main body 10A. The 3 balls 71 arranged in the locking position generate: the force pressing the anvil body 10A toward the radially inner side. The force with which the 3 balls 71 press the anvil body 10A is uniform. The tip tool BT is fixed to the anvil body 10A by 3 balls 71 so that the rotation axis AX of the anvil 10 coincides with the center axis of the tip tool BT. By appropriately positioning the tip tool BT in all of the axial direction, the radial direction, and the circumferential direction, the operability of the electric power tool 1 becomes good.

Fig. 25 is a sectional view showing a tool holder 11Bb according to the present embodiment. As shown in fig. 25, the number of the balls 71 may be 1. Even if the number of the balls 71 is 1, the tip tool BT can be fixed to the anvil body 10A so that the rotation axis AX of the anvil 10 coincides with the center axis of the tip tool BT.

Further, as long as the rotation axis AX of the anvil 10 coincides with the center axis of the tip tool BT, the number of the balls 71 may be 1 or more. As described above, 1 or 3 balls 71 may be provided, or any odd number of 5 or more balls 71 may be provided around the anvil body 10A. Further, 4 balls 71 may be provided around the anvil body 10A.

[ embodiment 3 ]

Embodiment 3 will be explained. In the following description, the same or equivalent constituent elements as those of the above-described embodiment are given the same reference numerals, and the description thereof will be omitted or simplified.

Fig. 26 is a transverse cross-sectional view showing a tool holder 11C according to the present embodiment. As in the above-described embodiment, the tool holding device 11C includes: a ball 71 movable between a lock position and a release position; a 1 st elastic member 72 that generates an elastic force to move the ball 71 toward the lock position; a sleeve 73 that is movable between a blocking position that blocks movement of the balls 71 radially outward and an allowing position that allows movement of the balls 71 radially outward; a 2 nd elastic member 74 generating an elastic force to move the sleeve 73 toward the blocking position; and a positioning member 75 that positions the sleeve 73 in the blocking position.

Fig. 26 shows: the sleeve 73 is disposed in the blocking position and the tip tool BT is locked by the ball 71.

In the present embodiment, the tool holding device 11C includes: and a pulling-out device 200 for generating a force to pull out the tip tool BT from the insertion hole 55. The extraction device 200, during the movement of the sleeve 73 from the blocking position towards the allowing position, generates: force to take out the tip tool BT from the insertion hole 55. At least a part of the drawer device 200 is disposed inside the insertion hole 55.

As in the above-described embodiment, an opening 55A is provided at the distal end of the insertion hole 55. A bottom surface 55B is provided at the rear end of the insertion hole 55. In this embodiment, the bottom surface 55B includes the front surface of the gasket 78. The washer 78 is disc-shaped. The washer 78 is supported by a snap ring 79. A circlip is illustrated as the stop ring 79. The insertion hole 55 has, on its inner surface: and a recess 79R into which the peripheral edge of the stopper ring 79 is fitted. By fitting the peripheral edge portion of the stopper ring 79 into the recess 79R, the stopper ring 79 is fixed to the anvil 10 inside the insertion hole 55. By fixing the snap ring 79, the washer 78 supported by the snap ring 79 is positioned.

Fig. 27 is a perspective view of the drawer device 200 according to the present embodiment. Fig. 27 corresponds to a drawing of the extracting apparatus 200 from the electric power tool 1.

As shown in fig. 26 and 27, the drawer device 200 includes: a piston member 76, and a pull-out resilient member 77.

The piston member 76 is movable in the axial direction inside the insertion hole 55. The piston member 76 is movable in the axial direction while supporting the rear end portion of the front end tool BT.

The extraction elastic member 77 produces: and a spring force for moving the piston member 76 toward the opening 55A of the insertion hole 55. The extraction elastic member 77 includes a compression coil spring. The extraction elastic member 77 is supported by the bottom surface 55B of the insertion hole 55.

The piston member 76 has: bottom plate portion 76B; a peripheral wall portion 76T protruding forward from the peripheral edge portion of the bottom plate portion 76B; and a flange portion 76F extending radially outward from the front end portion of the peripheral wall portion 76T.

The outer shape of the bottom plate portion 76B is circular in a cross section orthogonal to the rotation axis AX. The peripheral wall portion 76T is cylindrical. The peripheral edge of bottom plate 76B is connected to the rear end of peripheral wall 76T. In a cross section orthogonal to the rotation axis AX, the flange portion 76F has an outer diameter larger than: the outer diameter of the bottom plate portion 76B and the outer diameter of the peripheral wall portion 76T. The outer surface of the peripheral wall portion 76T faces the inner surface of the insertion hole 55 with a gap therebetween. That is, a space 76C is formed between the outer surface of the peripheral wall portion 76T and the inner surface of the insertion hole 55. The outer surface of the flange portion 76F contacts the inner surface of the insertion hole 55. The piston member 76 moves in the axial direction while bringing the outer surface of the flange portion 76F into contact with the inner surface of the insertion hole 55. The flange portion 76F is guided by the inner surface of the insertion hole 55. The piston member 76 moves in the axial direction while being guided by the inner surface of the insertion hole 55.

An opening 76H is provided at the distal end of the piston member 76. The rear end portion of the front end tool BT is inserted into the internal space of the piston member 76 through the opening 76H. The rear end portion of the front end tool BT is in contact with the front surface of the bottom plate portion 76B. Further, the rear end portion of the front end tool BT may contact the inner surface of the peripheral wall portion 76T. Further, at least a part of the tip tool BT may be in contact with the front surface of the flange portion 76F.

At least a portion of the extraction spring 77 is configured to: the peripheral wall portion 76T is surrounded between the bottom surface 55B and the rear surface of the flange portion 76F. The front end portion of the pull-out elastic member 77 contacts the rear surface of the flange portion 76F. The rear end of the pull-out spring member 77 contacts the bottom surface 55B.

As shown in fig. 26, at least a part of the ball 71 is disposed inside the groove portion B2, and the pull-out elastic member 77 is disposed in a state where the tool bit BT is locked by the ball 71: the peripheral wall portion 76T is surrounded between the bottom surface 55B and the flange portion 76F. The extraction elastic member 77 is disposed: a space 76C between the outer surface of the peripheral wall portion 76T and the inner surface of the insertion hole 55. In a state where the tool bit BT is locked by the ball 71, the bottom plate portion 76B of the piston member 76 contacts the bottom surface 55B.

Fig. 28 is a transverse cross-sectional view showing the tool holder 11C according to the present embodiment. Fig. 28 shows: the sleeve 73 is disposed at the allowing position and the lock of the tool bit BT is released.

As in the above-described embodiment, the worker moves the sleeve 73 forward to dispose the 1 st portion 89 at a position radially outside the ball 71, so that the ball 71 becomes: a state in which the movable member can move radially outward. That is, when the sleeve 73 is moved from the blocking position to the permitting position by the operation of the operator, the balls 71 change to: a state in which the movable member can move toward the release position.

The extraction elastic member 77 produces: when the ball 71 is changed to a state in which it can move toward the release position including the 1 st portion 89 by the elastic force for moving the piston member 76 toward the opening 55A, the tip tool BT starts moving forward by pulling out the elastic force of the elastic member 77. When the tip tool BT moves forward, the ball 71 moves radially outward by contact with the tip tool BT.

The piston member 76 and the tool bit BT supported by the piston member 76 are further moved forward by the elastic force generated by the elastic member 77. The ball 71 is in contact with the surface of the fitting portion B1, thereby moving toward the radially outer side. Accordingly, the balls 71 move from the locked position to the released position. At least a portion of the balls 71 are disposed in the 1 st section 89 of the sleeve 73.

When the ball 71 moves radially outward and is disposed at the release position, the tip tool BT moves forward by pulling out the elastic force of the elastic member 77. The tip tool BT moves forward while bringing the outer surface of the mounting portion B1 into contact with the surface of the ball 71. The piston member 76 moves forward while bringing the outer surface を of the flange portion 76F into contact with the inner surface of the insertion hole 55.

Thus, when the worker moves the sleeve 73 from the blocking position to the allowing position, the piston member 76 and the tool bit BT supported by the piston member 76 are automatically moved forward by pulling out the elastic force of the elastic member 77.

As described above, according to the present embodiment, the tip tool BT can be automatically moved by the elastic force of the pull-out elastic member 77 by simply operating the sleeve 73 to move from the operation-preventing position to the allowing position, and the tip tool BT can be taken out from the insertion hole 55. The operator can easily remove the tip tool BT from the insertion hole 55. Since the tool holder 11C can be used with good operability, the electric power tool 1 can be operated with good operability, and a reduction in work efficiency of the operator can be suppressed.

As described with reference to fig. 26, in the state where the tip tool BT is locked by the ball 71, the extraction elastic member 77 is arranged to: the peripheral wall portion 76T is surrounded between the bottom surface 55B and the flange portion 76F, and the bottom plate portion 76B of the piston member 76 is in contact with the bottom surface 55B. That is, in the state where the tool bit BT is locked, the bottom plate portion 76B of the piston member 76 is supported by the bottom surface 55B. Accordingly, when the work target is machined by the tip tool BT, the load transmitted to the piston member 76 via the tip tool BT is transmitted to the bottom surface 55B. Accordingly, when the tool bit BT is used to process a work target, the tool bit BT can be prevented from moving relative to the anvil 10.

Further, the rear end portion of the front end tool BT may not be disposed in the internal space of the piston member 76. The rear end portion of the front end tool BT may be supported on the front surface of the flange portion 76F, for example.

[ other embodiments ]

In the above embodiment, the electric power tool 1 is an impact driver. The electric power tool 1 is not limited to the impact driver. As the electric power tool 1, there can be exemplified: screwdriver drills, angle drills, hammers, and hammer drills.

In the above embodiment, the battery pack 25 attached to the battery attachment portion 5 is used as a power source of the electric power tool 1. As the power source of the electric power tool 1, a commercial power source (ac power source) can be used.

In the above embodiment, the screw tightening tool is: an electric tool having a motor 6 (electric motor) as a power source. The power source of the screw tightening tool may be a pneumatic motor driven by compressed air, a hydraulic motor, or a motor driven by an engine.

Claims

1. A screw tightening tool for tightening a screw, comprising a tightening screw,

the screw fastening tool includes:

a motor;

an output shaft that rotates by power transmitted from the motor; and

a tool holding device for holding a tool inserted into an insertion hole of the output shaft,

the tool holding device includes:

a lock member supported by the output shaft and movable between a lock position for locking the tip tool and a release position for releasing the lock;

a 1 st elastic member that generates an elastic force for moving the lock member toward the lock position;

a sleeve that is movable around the output shaft between a blocking position that blocks movement of the lock member radially outward and an allowing position that allows movement of the lock member radially outward;

a 2 nd elastic member that generates an elastic force to move the sleeve toward the stopping position; and

a positioning member fixed to an outer surface of the output shaft and positioning the sleeve at the stopping position,

in a cross section parallel to the rotation axis of the output shaft, a contact surface of the positioning member that contacts the sleeve is a curved surface.

2. The screw tightening tool according to claim 1,

in the cross section, the outer shape of the positioning member is circular.

3. The screw tightening tool according to claim 2,

at least a portion of the positioning member is configured to: a 1 st recess formed in an outer surface of the output shaft,

in the cross section, the depth of the 1 st recess is the same as the radius of the positioning member, or the depth of the 1 st recess is larger than the radius of the positioning member.

4. The screw tightening tool according to any one of claims 1 to 3,

the screw tightening tool includes: a 2 nd recess provided at a rear end portion of the sleeve,

the contact surface of the positioning member is in contact with the inner surface of the 2 nd recess.

5. The screw tightening tool according to claim 4,

the locking member is spherical and is supported: a bearing recess formed in an outer surface of the output shaft,

the output shaft is provided with: a through hole for connecting an inner surface of the support concave portion and an inner surface of the insertion hole,

at least a part of the locking member is disposed in a groove provided on a side surface of the tool bit through the through hole, whereby the tool bit is locked,

the locking position includes: at least a part of the locking member is disposed at a position of the groove portion.

6. The screw tightening tool according to claim 5,

the locking part is provided with an odd number.

7. The screw tightening tool according to claim 5,

the number of the locking members is 3 around the output shaft.

8. The screw tightening tool according to any one of claims 1 to 3,

the screw tightening tool includes a pulling-out device that generates a force to pull out the tip tool from the insertion hole in a process in which the sleeve moves from the prevention position to the permission position.

9. A screw tightening tool for tightening a screw, comprising a tightening screw,

the screw fastening tool includes:

a motor;

an output shaft that rotates by power transmitted from the motor; and

the tool holding device includes:

10. The screw tightening tool according to claim 9,

the locking part is provided with an odd number.

11. The screw tightening tool according to claim 9,

the number of the locking members is 3 around the output shaft.

12. The screw tightening tool according to claim 9,

13. A screw tightening tool for tightening a screw, comprising a tightening screw,

the screw fastening tool includes:

a motor;

an output shaft that rotates by power transmitted from the motor; and

the tool holding device includes:

a 2 nd elastic member that generates an elastic force to move the sleeve toward the stopping position;

a positioning member fixed to an outer surface of the output shaft and positioning the sleeve at the stopping position; and

an extraction device that generates a force to extract the tip tool from the insertion hole during movement of the sleeve from the prevention position toward the permission position.

14. The screw tightening tool according to claim 13,

at least a part of the extraction device is configured to: an inner position of the insertion hole.

15. The screw tightening tool according to claim 13,

an opening is provided at a front end portion of the insertion hole,

a bottom surface is provided at a rear end portion of the insertion hole,

the extraction device comprises:

a piston member that is movable in an axial direction inside the insertion hole and supports a rear end portion of the tip tool; and

and a pull-out elastic member that is supported by a bottom surface of the insertion hole and generates an elastic force for moving the piston member toward the opening of the insertion hole.

16. The screw tightening tool according to claim 15,

the piston member has: a bottom plate portion, a peripheral wall portion protruding forward from a peripheral edge portion of the bottom plate portion, and a flange portion extending radially outward from a front end portion of the peripheral wall portion,

in a state where the tip tool is locked by the locking member, the extraction elastic member is configured to: the peripheral wall portion is surrounded between the bottom surface and the flange portion, and a bottom plate portion of the piston member is in contact with the bottom surface.

17. The screw tightening tool according to any one of claims 1, 9, and 13,

moving the locking member towards the allowed position by the sleeve such that the locking member changes to: a state in which the movable member can move toward the release position.

18. The screw tightening tool according to any one of claims 1, 9, and 13,

the sleeve has:

a protrusion portion that protrudes radially inward and is capable of contacting the output shaft;

a 1 st groove provided at a position rearward of the projection and facing the output shaft; and

a 2 nd groove provided at a position forward of the projection and facing the output shaft,

the 1 st elastic member is disposed at a position inside the 1 st groove,

the 2 nd elastic member is disposed at a position inside the 2 nd groove.

19. The screw tightening tool according to claim 18,

the protrusion is contactable with the locking member.

20. The screw tightening tool according to claim 19,

the 1 st slot includes: a 1 st portion for disposing at least a part of the locking member that moves radially outward; and a 2 nd part connected to the 1 st part and configured to dispose at least a part of the 1 st elastic member.

21. The screw tightening tool according to any one of claims 1, 9, and 13,

the output shaft has: a 3 rd groove provided in a manner facing the sleeve and for disposing the 1 st elastic member,

the 3 rd groove has: a bottom; a wall portion provided behind the bottom portion and in contact with the 1 st elastic member; and a tapered portion provided forward of the bottom portion and inclined radially outward toward the front.

22. The screw tightening tool according to any one of claims 1, 9, and 13,

the 1 st elastic member is a compression coil spring,

the front end portion of the 1 st elastic member is in contact with the lock member, and the rear end portion of the 1 st elastic member is in contact with at least a portion of the output shaft.

23. The screw tightening tool according to any one of claims 1, 9, and 13,

the sleeve has: an inclined surface contacting the locking member moving toward a radially outer side,

the sleeve is moved toward the permitting position by contact between the locking member and the inclined surface,

an angle formed by the rotating shaft of the output shaft and the inclined surface is larger than 45 degrees and smaller than 90 degrees.