Impact wrench

Abstract

To inhibit deterioration of strength of an anvil.SOLUTION: An impact wrench includes: a motor; a hammer which is disposed at the front relative to the motor and rotated around a rotation axis extending in a front-back direction by the motor; an anvil which is struck in a rotation direction by the hammer; an anvil bearing rotatably supporting the anvil; and a wire disposed in the anvil. The anvil has: a square pole part to which the socket is attached; and a columnar part which is connected to a rear end part of the square pole part and supported by the anvil bearing. A front part of the wire is connected to the square pole part and a rear part of the wire is held by a holding part of the anvil located at the rear relative to the rear end part of the square pole part.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The technology disclosed in this specification relates to an impact wrench. [Background technology]

[0002] In the technical field related to impact wrenches, there is known an impact tool that aims to prevent a part of the anvil from falling off, as disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6801571 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technique disclosed in Patent Document 1, a thin-walled portion that is easily broken is provided on the anvil body. The presence of the thin-walled portion may reduce the strength of the anvil.

[0005] The technology disclosed in this specification aims to suppress a decrease in the strength of the anvil. [Means for solving the problem]

[0006] This specification discloses an impact wrench. The impact wrench may include a motor, a hammer disposed forward of the motor and rotated by the motor about a rotation axis extending in the front-rear direction, an anvil struck in the rotational direction by the hammer, an anvil bearing rotatably supporting the anvil, and a wire disposed inside the anvil. The anvil may have a square column portion to which a socket is attached, and a cylindrical portion connected to a rear end of the square column portion and supported by the anvil bearing. A front portion of the wire may be connected to the square column portion. A rear portion of the wire may be held by a holding portion of the anvil rearward of the square column portion. Effect of the Invention

[0007] According to the above configuration, a decrease in the strength of the anvil is suppressed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a front perspective view showing an impact wrench according to an embodiment. [Diagram 2] FIG. 2 is a side view showing the impact wrench according to the embodiment. [Diagram 3] FIG. 3 is a vertical cross-sectional view showing the impact wrench according to the embodiment. [Figure 4] FIG. 4 is a vertical cross-sectional view showing an upper portion of the impact wrench according to the embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing an upper portion of the impact wrench according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing the front part of the upper part of the impact wrench according to the embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a separation suppression mechanism according to the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a separation suppression mechanism according to the embodiment. [Figure 9] FIG. 9 is a rear view of the separation suppression mechanism according to the embodiment. [Figure 10] FIG. 10 is a front view of the separation suppression mechanism according to the embodiment. [Figure 11] FIG. 11 is an exploded perspective view showing a separation suppression mechanism according to the embodiment. [Figure 12] FIG. 12 is a side view showing a separation suppression mechanism according to the embodiment. [Figure 13] FIG. 13 is a perspective view showing a separation suppression mechanism according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one or more embodiments, the impact wrench may include a motor, a hammer disposed forward of the motor and rotated by the motor about a rotation axis extending in the front-rear direction, an anvil struck in the rotational direction by the hammer, an anvil bearing rotatably supporting the anvil, and a wire disposed inside the anvil. The anvil may have a square column portion to which the socket is attached, and a cylindrical portion connected to a rear end of the square column portion and supported by the anvil bearing. A front portion of the wire may be connected to the square column portion. A rear portion of the wire may be held by a holding portion of the anvil rearward of the rear end of the square column portion.

[0010] In the above configuration, the front part of the wire is connected to the square column part, and the rear part of the wire is held by the holding part behind the rear end of the square column part, so that even if the boundary between the rear end of the square column part and the front end of the cylindrical part breaks, the wire prevents the front part of the anvil from falling off. In general, in the anvil of an impact wrench, there is a high possibility of breakage at the boundary between the rear end of the square column part and the front end of the cylindrical part. Since the wire is disposed inside the anvil, even if the anvil does not have a thin-walled part, the front part of the anvil is prevented from falling off when the boundary between the rear end of the square column part and the front end of the cylindrical part breaks. Since the anvil does not have to have a thin-walled part, a decrease in the strength of the anvil is suppressed.

[0011] In one or more embodiments, a passage hole extending in the front-rear direction and a retaining hole connected to a rear end of the passage hole and having a larger diameter than the passage hole may be provided inside the anvil. The impact wrench may include a retaining member connected to a rear portion of the wire. The retaining portion may include a retaining hole. The rear portion of the wire may be retained in the retaining hole via the retaining member.

[0012] In the above configuration, the rear portion of the wire is held in the holding hole via the retaining member.

[0013] In one or more embodiments, a rearwardly facing boundary surface may be provided at the boundary between the rear end of the passage hole and the front end of the retaining hole, and the front end surface of the retaining member may contact the boundary surface.

[0014] In the above configuration, the front end face of the anti-slip member contacts the boundary surface, thereby preventing the anti-slip member and the wire from moving forward relative to the anvil.

[0015] In one or more embodiments, the shape and dimensions of the inner edge of the passage hole perpendicular to the rotation axis may be equal to the shape and dimensions of the outer edge of the retaining member perpendicular to the rotation axis. The retaining member may pass through the passage hole and be received in the retaining hole.

[0016] In the above configuration, the shape of the inner edge of the passage hole perpendicular to the rotation axis and the shape of the outer edge of the retaining member are substantially equal. The dimensions of the inner edge of the passage hole perpendicular to the rotation axis and the dimensions of the outer edge of the retaining member are substantially equal. The retaining member is lightly press-fitted into the passage hole from the opening at the front end of the passage hole. While lightly press-fitted into the passage hole, the retaining member passes through the passage hole toward the rear and is then housed in the retaining hole.

[0017] In one or more embodiments, the retaining member may be positioned in the retention hole at a different rotational angle than the angle at which it passes through the passage hole.

[0018] In the above configuration, the retaining member, which is lightly press-fitted into the passage hole and passes rearward through the passage hole, is accommodated in the retaining hole and then has its rotational angle changed, causing the front end surface of the retaining member to come into contact with the boundary surface.

[0019] In one or more embodiments, the outer edge of the retaining member may be rectangular in shape.

[0020] In the above configuration, the shape of the inner edge of the passage hole and the shape of the outer edge of the retaining member are both rectangular, so the probability that the outer edge of the retaining member housed in the retaining hole will coincide with the inner edge of the passage hole is low. Therefore, the retaining member housed in the retaining hole is prevented from entering the passage hole. The shape of the outer edge of the retaining member may be triangular, any polygon having pentagons or more, or elliptical. The shape of the outer edge of the retaining member may be any shape other than circular.

[0021] In one or more embodiments, the front end of the retention hole may be located between the rear end and the front end of the cylindrical portion in the front-to-rear direction.

[0022] In the above configuration, the length of the passage hole in the front-rear direction is prevented from becoming excessively long.

[0023] In one or more embodiments, a front end of the retention hole may be located rearward of a center portion of the cylindrical portion in the front-to-rear direction.

[0024] In the above configuration, the length of the passage hole in the front-rear direction is prevented from becoming excessively short.

[0025] In one or more embodiments, a circumferential groove may be provided on the outer peripheral surface of the anvil, the circumferential groove being connected to a rear end of the cylindrical portion, and a front end of the circumferential groove may be disposed rearward of a front end of the retaining hole in the front-rear direction.

[0026] In the above configuration, the length of the passage hole in the front-rear direction is prevented from becoming excessively long.

[0027] In one or more embodiments, a rear end of the circumferential groove may be located forward of a rear end of the retention hole in the front-to-rear direction.

[0028] In the above configuration, the length of the circumferential groove in the front-rear direction is prevented from becoming excessively long.

[0029] In one or more embodiments, the impact wrench may include a spindle that supports the hammer. A recess may be provided inside the anvil, connected to the rear end of the retaining hole and having a larger diameter than the retaining hole. A protrusion provided on the front end of the spindle may be inserted into the recess. The impact wrench may include an O-ring that seals the boundary between the recess and the protrusion.

[0030] The above configuration prevents the lubricant around the spindle from leaking out to the outside of the impact wrench through the anvil.

[0031] In one or more embodiments, the retaining member may have a slide hole in which the wire is disposed. The retaining member may be movable relative to the wire. The impact wrench may include a stopper member fixed to a rear end of the wire to prevent the retaining member from being pulled out rearward from the wire.

[0032] In the above configuration, the retaining member is movable relative to the wire, which prevents the workability from decreasing when the retaining member is lightly press-fitted into the passage hole. Also, since the retaining member is movable relative to the wire, the stopper member of the retaining member is easy to assemble. Also, since the retaining member is rectangular, it can rotate (slide) when it comes out of the passage hole, which makes it effective as a retainer.

[0033] In one or more embodiments, the front portion of the wire may be connected to the rectangular post portion via a pin.

[0034] In the above configuration, the front portion of the wire is connected to the square prism portion via the pin, so that deterioration in workability when connecting the front portion of the wire to the square prism portion is suppressed.

[0035] In one or more embodiments, the wire may have a straight portion extending in the front-rear direction and a ring portion provided at a front end of the straight portion. The anvil may have a pin hole connecting an outer surface of the rectangular column portion and the passage hole. A pin may be inserted into each of the pin hole and the ring portion.

[0036] In the above configuration, the pin is inserted into the pin hole and the ring portion, respectively, so that the front portion of the wire and the rectangular column portion are connected with good operability.

[0037] In one or more embodiments, the retaining member may have a slide hole in which the straight portion is disposed. The retaining member may be movable relative to the straight portion. The impact wrench may include a stopper member fixed to a rear end of the straight portion and configured to prevent the retaining member from being pulled out rearward from the wire.

[0038] In the above-described configuration, the retaining member is movable relative to the straight portion, so that deterioration in operability when lightly press-fitting the retaining member into the passage hole is suppressed.

[0039] In one or more embodiments, the ring portion may be formed by bending a tip portion of a wire material. The impact wrench may include a crimping member that fixes a part of the ring portion and the straight portion.

[0040] In the above configuration, a wire having a ring portion and a straight portion is formed from a single wire material.

[0041] In one or more embodiments, the inner surface of the passage hole may be provided with a positioning groove into which at least a portion of the ring portion is positioned.

[0042] In the above configuration, the ring portion and the anvil are positioned.

[0043] In one or more embodiments, the position of the positioning groove may coincide with the position of at least a portion of the pin hole in the anterior-posterior direction.

[0044] In the above configuration, the ring portion and the pin hole are positioned.

[0045] In one or more embodiments, the locating groove may position the ring portion such that a central axis of the pin hole and a central axis of the ring portion coincide.

[0046] With the above configuration, it becomes easier to insert the pin into the pin hole and the ring portion.

[0047] In one or more embodiments, a spring portion may be provided on a portion of the straight portion.

[0048] In the above configuration, if the boundary between the rear end of the rectangular prism portion and the front end of the cylindrical portion breaks, excessive tension is prevented from being applied to the wire.

[0049] Hereinafter, an embodiment will be described with reference to the drawings. In the embodiment, the positional relationship of each part will be described using the terms left, right, front, rear, top, and bottom. These terms indicate relative positions or directions based on the center of the impact wrench.

[0050] [Impact tools] Fig. 1 is a front perspective view showing an impact wrench 1 according to an embodiment. Fig. 2 is a side view showing the impact wrench 1 according to an embodiment. Fig. 3 is a vertical cross-sectional view showing the impact wrench 1 according to an embodiment. Fig. 4 is a vertical cross-sectional view showing an upper part of the impact wrench 1 according to an embodiment. Fig. 5 is a horizontal cross-sectional view showing an upper part of the impact wrench 1 according to an embodiment.

[0051] In the embodiment, the impact wrench 1 is an electric tool having an electric motor 6 as a power source. A direction parallel to the rotation axis AX of the motor 6 is appropriately referred to as an axial direction, a direction going around the rotation axis AX is appropriately referred to as a circumferential direction or a rotation direction, and a radial direction of the rotation axis AX is appropriately referred to as a radial direction. In addition, in the radial direction, a position close to or approaching the rotation axis AX is appropriately referred to as a radially inner side or an inner circumferential side, and a position far from or away from the rotation axis AX is appropriately referred to as a radially outer side or an outer circumferential side. In the embodiment, the rotation axis AX extends in the front-rear direction. One axial side is the front side (forward), and the other axial side is the rear side (rear).

[0052] The impact wrench 1 comprises a housing 2, a rear cover 3, a hammer case 4, a bearing box 24, a motor 6, a reduction mechanism 7, a spindle 8, an impact mechanism 9, an anvil 10, a fan 12, a battery mounting section 13, a trigger lever 14, a forward / reverse rotation switching lever 15, an operation display section 16, a light 17, a controller 18, and a separation suppression mechanism 60.

[0053] The housing 2 is made of synthetic resin. In this embodiment, the housing 2 is made of nylon. The housing 2 includes a left housing 2L and a right housing 2R disposed to the right of the left housing 2L. The left housing 2L and the right housing 2R are fixed together by a plurality of screws 2S. The housing 2 is composed of a pair of half housings.

[0054] The housing 2 has a motor accommodating portion 21, a grip portion 22, and a battery holding portion 23.

[0055] The motor accommodating portion 21 is cylindrical and accommodates the motor 6 and the rear part of the bearing box 24. The motor accommodating portion 21 is provided with a screw boss portion 2H.

[0056] The grip portion 22 protrudes downward from the motor housing portion 21. The trigger lever 14 is provided on an upper portion of the grip portion 22. The grip portion 22 is held by an operator.

[0057] The battery holding portion 23 is connected to a lower end portion of the grip portion 22. The outer dimensions of the battery holding portion 23 are larger than the outer dimensions of the grip portion 22 in both the front-rear direction and the left-right direction.

[0058] The rear cover 3 is made of synthetic resin. The rear cover 3 is disposed behind the motor accommodating portion 21. The rear cover 3 is disposed so as to cover an opening at the rear end portion of the motor accommodating portion 21. The rear cover 3 is fixed to the rear end portion of the motor accommodating portion 21 by screws (not shown).

[0059] The rear cover 3 has an air intake port 19. The motor accommodating section 21 has an air exhaust port 20. Air in the external space of the housing 2 flows into the internal space of the housing 2 through the air intake port 19. Air in the internal space of the housing 2 flows out to the external space of the housing 2 through the air exhaust port 20.

[0060] The bearing box 24 houses the reduction mechanism 7. The hammer case 4 houses the spindle 8. The hammer case 4 houses the striking mechanism 9. The hammer case 4 houses a part of the anvil 10. The hammer case 4 is made of metal. In the embodiment, the hammer case 4 is made of aluminum. The hammer case 4 is cylindrical. A part of the surface of the hammer case 4 is covered by a cover 400.

[0061] The hammer case 4 includes a rear cylinder portion 4A, a front cylinder portion 4B, an annular portion 4C, and a screw boss portion 4H. The front cylinder portion 4B is disposed forward of the rear cylinder portion 4A. The outer diameter of the rear cylinder portion 4A is larger than the outer diameter of the front cylinder portion 4B. The inner diameter of the rear cylinder portion 4A is larger than the inner diameter of the front cylinder portion 4B. The annular portion 4C is disposed to connect the front end portion of the rear cylinder portion 4A and the rear end portion of the front cylinder portion 4B.

[0062] The rear of the hammer case 4 and the front of the motor housing 21 are fixed together via a bearing box 24. The hammer case 4 and the motor housing 21 are fixed together by screws 5. The screws 5 are inserted into openings provided in the screw boss portion 2H from the rear of the screw boss portion 2H, and then inserted into threaded holes provided in the screw boss portion 4H. Four screw boss portions 2H and four screw boss portions 4H are provided in the circumferential direction. Four screws 5 are provided in the circumferential direction.

[0063] The bearing box 24 is fixed to a rear portion of the rear cylinder portion 4A. The reduction gear mechanism 7 is disposed inside the bearing box 24. The hammer case 4 is sandwiched between the left housing 2L and the right housing 2R. The rear portion of the bearing box 24 is accommodated in the motor accommodating portion 21. The bearing box 24 is fixed to both the motor accommodating portion 21 and the hammer case 4.

[0064] The motor 6 is a power source of the impact wrench 1. The motor 6 generates a rotational force. The motor 6 is an electric motor. The motor 6 is an inner rotor type brushless motor. The motor 6 has a stator 26 and a rotor 27. The stator 26 is supported by the motor accommodating portion 21. At least a portion of the rotor 27 is disposed inside the stator 26. The rotor 27 rotates relative to the stator 26. The rotor 27 rotates about a rotation axis AX extending in the front-rear direction.

[0065] The stator 26 includes a stator core 28 , a front insulator 29 , a rear insulator 30 , and a coil 31 .

[0066] The stator core 28 is disposed radially outward of the rotor 27. The stator core 28 includes a plurality of stacked steel plates. The steel plates are metal plates whose main component is iron. The stator core 28 is cylindrical. The stator core 28 has a plurality of teeth that support the coils 31.

[0067] The front insulator 29 is provided at the front of the stator core 28. The rear insulator 30 is provided at the rear of the stator core 28. The front insulator 29 and the rear insulator 30 are each an electrical insulating member made of synthetic resin. The front insulator 29 is disposed so as to cover a portion of the surface of the teeth. The rear insulator 30 is disposed so as to cover a portion of the surface of the teeth.

[0068] The coil 31 is attached to the stator core 28 via the front insulator 29 and the rear insulator 30. A plurality of coils 31 are arranged. The coils 31 are arranged around the teeth of the stator core 28 via the front insulator 29 and the rear insulator 30. The coils 31 and the stator core 28 are electrically insulated by the front insulator 29 and the rear insulator 30. The multiple coils 31 are connected via a bus bar 38.

[0069] The rotor 27 rotates about a rotation axis AX. The rotor 27 includes a rotor core 32, a rotor shaft 33, and a rotor magnet .

[0070] The rotor core 32 is made of steel. The rotor core 32 is cylindrical. The rotor shaft 33 is disposed inside the rotor core 32. The rotor core 32 and the rotor shaft 33 are fixed. A front portion of the rotor shaft 33 protrudes forward from a front end surface of the rotor core 32. A rear portion of the rotor shaft 33 protrudes rearward from a rear end surface of the rotor core 32.

[0071] The rotor magnet 34 is fixed to the rotor core 32. The rotor magnet 34 is disposed inside the rotor core 32.

[0072] A sensor board 37 is attached to the rear insulator 30. The sensor board 37 has a circular circuit board and a magnetic sensor supported by the circuit board. At least a portion of the sensor board 37 faces the rotor magnet 34. The magnetic sensor detects the position of the rotor magnet 34, thereby detecting the position of the rotor 27 in the rotational direction.

[0073] A rear portion of the rotor shaft 33 is rotatably supported by a rotor bearing 39. A front portion of the rotor bearing 39 is rotatably supported by a rotor bearing 40. The rotor bearing 39 is held by the rear cover 3. The rotor bearing 40 is held by the bearing box 24. The front end portion of the rotor shaft 33 is disposed in the internal space of the bearing box 24 through an opening of the bearing box 24.

[0074] A pinion gear 41 is formed on the front end of the rotor shaft 33. The pinion gear 41 is connected to at least a part of the reduction gear mechanism 7. The rotor shaft 33 is connected to the reduction gear mechanism 7 via the pinion gear 41.

[0075] The reduction mechanism 7 transmits the rotational force of the motor 6 to the spindle 8 and the anvil 10. The reduction mechanism 7 is housed in the bearing box 24. The reduction mechanism 7 has a plurality of gears. The reduction mechanism 7 is disposed forward of the motor 6. The reduction mechanism 7 connects the rotor shaft 33 and the spindle 8. The gears of the reduction mechanism 7 are driven by the rotor 27. The reduction mechanism 7 transmits the rotation of the rotor 27 to the spindle 8. The reduction mechanism 7 rotates the spindle 8 at a rotational speed lower than the rotational speed of the rotor shaft 33. The reduction mechanism 7 includes a planetary gear mechanism.

[0076] The reduction mechanism 7 has a plurality of planetary gears 42 arranged around the pinion gear 41, and an internal gear 43 arranged around the plurality of planetary gears 42. The pinion gear 41, the planetary gear 42, and the internal gear 43 are each housed in the bearing box 24. Each of the plurality of planetary gears 42 meshes with the pinion gear 41. The planetary gear 42 is rotatably supported by the spindle 8 via a pin 42P. The spindle 8 is rotated by the planetary gear 42. The internal gear 43 has internal teeth that mesh with the planetary gear 42. The internal gear 43 is fixed to the bearing box 24. The internal gear 43 is always non-rotatable with respect to the bearing box 24.

[0077] When the rotor shaft 33 is rotated by the drive of the motor 6, the pinion gear 41 rotates 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. Due to the revolution of the planetary gear 42, the spindle 8 connected to the planetary gear 42 via the pin 42P rotates at a rotational speed lower than the rotational speed of the rotor shaft 33.

[0078] The spindle 8 rotates due to the rotational force of the motor 6. The spindle 8 is disposed forward of at least a portion of the motor 6. The spindle 8 is disposed forward of the stator 26. At least a portion of the spindle 8 is disposed forward of the rotor 27. At least a portion of the spindle 8 is disposed in front of the reduction mechanism 7. The spindle 8 is rotated by the rotor 27. The spindle 8 rotates due to the rotational force of the rotor 27 transmitted by the reduction mechanism 7.

[0079] The spindle 8 has a flange portion 8A and a spindle shaft portion 8B that protrudes forward from the flange portion 8A. The planetary gear 42 is rotatably supported on the flange portion 8A via a pin 42P. The rotation axis of the spindle 8 and the rotation axis AX of the motor 6 coincide with each other. The spindle 8 rotates about the rotation axis AX.

[0080] The spindle 8 is rotatably supported by a spindle bearing 44. The spindle bearing 44 is held in the bearing box 24. The spindle 8 has an annular portion 8C protruding rearward from the rear of the flange portion 8A. The spindle bearing 44 is disposed around the annular portion 8C. In the embodiment, an outer ring of the spindle bearing 44 is held in the bearing box 24, and the annular portion 8C is held by an inner ring of the spindle bearing 44.

[0081] The striking mechanism 9 is driven by the motor 6. The rotational force of the motor 6 is transmitted to the striking mechanism 9 via the reduction mechanism 7 and the spindle 8. The striking mechanism 9 strikes the anvil 10 in the rotational direction based on the rotational force of the spindle 8 rotated by the motor 6. The striking mechanism 9 has a hammer 47, a ball 48, and a coil spring 49. The striking mechanism 9 including the hammer 47 is housed in the hammer case 4.

[0082] The hammer 47 is disposed forward of the motor 6. The hammer 47 is disposed forward of the reduction mechanism 7. The hammer 47 is housed in the rear cylinder portion 4A. The hammer 47 is disposed around the spindle shaft portion 8B. The hammer 47 is supported by the spindle shaft portion 8B. The ball 48 is disposed between the spindle shaft portion 8B and the hammer 47. The coil spring 49 is supported by each of the flange portion 8A and the hammer 47.

[0083] The hammer 47 has an annular body portion 47D, an outer cylinder portion 47E protruding rearward from the outer periphery of the body portion 47D, an inner cylinder portion 47G protruding rearward from the inner periphery of the body portion 47D, a hammer groove 47A, and a hammer protrusion portion 47B. The body portion 47D is disposed around the spindle shaft portion 8B. The body portion 47D is annular. The outer cylinder portion 47E and the inner cylinder portion 47G each protrude rearward from the body portion 47D. A recess 47C is defined by the rear surface of the body portion 47D, the inner periphery of the outer cylinder portion 47E, and the outer periphery of the inner cylinder portion 47G. The recess 47C is provided so as to be recessed forward from the rear end portion of the hammer 47. The recess 47C is ring-shaped. The hammer protrusion portion 47B protrudes frontward from the body portion 47D. Two hammer protrusion portions 47B are provided. Since the outer cylinder portion 47E is provided, the inertial force of the hammer 47 in the rotational direction becomes large.

[0084] The hammer 47 is rotated by the motor 6. The rotational force of the motor 6 is transmitted to the hammer 47 via the reduction mechanism 7 and the spindle 8. The hammer 47 can rotate together with the spindle 8 based on the rotational force of the spindle 8 rotated by the motor 6. The rotation axis of the hammer 47, the rotation axis of the spindle 8, and the rotation axis AX of the motor 6 coincide with each other. The hammer 47 rotates around the rotation axis AX.

[0085] The ball 48 is made of a metal such as steel. The ball 48 is disposed between the spindle shaft portion 8B and the hammer 47. The spindle 8 has a spindle groove 8D in which at least a part of the ball 48 is disposed. The spindle groove 8D is provided on a part of the outer circumferential surface of the spindle shaft portion 8B. The hammer 47 has a hammer groove 47A in which at least a part of the ball 48 is disposed. The hammer groove 47A is provided on a part of the inner surface of the inner cylinder portion 47G. The ball 48 is disposed between the spindle groove 8D and the hammer groove 47A. The ball 48 can roll on the inside of the spindle groove 8D and the inside of the hammer groove 47A. The hammer 47 can move along with the ball 48. The spindle 8 and the hammer 47 can move relative to each other in the axial direction and the rotational direction within a movable range defined by the spindle groove 8D and the hammer groove 47A.

[0086] The coil spring 49 generates an elastic force that moves the hammer 47 forward. The coil spring 49 is disposed between the flange portion 8A and the hammer 47. A ring-shaped recess 47C is provided on the rear surface of the hammer 47. The recess 47C is recessed forward from the rear surface of the hammer 47. A washer 45 is provided inside the recess 47C. The washer 45 is supported by the body portion 47D via a ball 11. The ball 11 is disposed in a ball groove 47H provided on the rear surface of the body portion 47D. The rear end of the coil spring 49 is supported by the flange portion 8A. The front end of the coil spring 49 is disposed inside the recess 47C and supported by the washer 45.

[0087] The anvil 10 is an output part of the impact wrench 1 that is actuated by the torque of the motor 6. The anvil 10 is rotated by the torque of the motor 6. At least a portion of the anvil 10 is disposed forward of the hammer 47.

[0088] The anvil 10 has a rod-shaped anvil shaft portion 10C and an anvil protrusion portion 10D. The outer shape of a square column portion 10E at the front of the anvil shaft portion 10C, which is perpendicular to the rotation axis AX, is substantially square. A socket 50, which is a tip tool, is attached to the front of the anvil shaft portion 10C. A snap ring 51 is provided at the front of the anvil shaft portion 10C.

[0089] A recess 10B is provided at the rear end of the anvil 10. A protrusion 8E is provided at the front end of the spindle shaft portion 8B. The protrusion 8E at the front end of the spindle shaft portion 8B is inserted into the recess 10B provided at the rear end of the anvil 10. An O-ring 35 is provided between the outer peripheral surface of the protrusion 8E and the inner peripheral surface of the recess 10B. The O-ring 35 seals the boundary between the outer peripheral surface of the protrusion 8E and the inner peripheral surface of the recess 10B. The O-ring 35 prevents the lubricant around the spindle 8 from leaking out of the hammer case 4.

[0090] The anvil projection 10D is provided on the rear end portion of the anvil 10. The anvil projection 10D projects radially outward from the rear end portion of the anvil shaft portion 10C.

[0091] The anvil 10 is rotatably supported by the anvil bearing 46. The rotation axis of the anvil 10, the rotation axis of the hammer 47, the rotation axis of the spindle 8, and the rotation axis AX of the motor 6 are aligned. The anvil 10 rotates around the rotation axis AX. The anvil bearing 46 is disposed inside the front cylinder portion 4B. The anvil bearing 46 is held by the front cylinder portion 4B of the hammer case 4. The front cylinder portion 4B is disposed around the anvil shaft portion 10C. The anvil bearing 46 rotatably supports the anvil shaft portion 10C. In the embodiment, the anvil bearing 46 includes an outer sleeve 46A and an inner sleeve 46B disposed on the inner circumferential side of the outer sleeve 46A. The front end portion of the outer sleeve 46A is disposed forward of the front end portion of the inner sleeve 46B. The seal member 36 is disposed in front of the inner sleeve 46B. The seal member 36 is disposed inside the front portion of the outer sleeve 46A. The seal member 36 seals the boundary between the inner circumferential surface of the outer sleeve 46A and the outer circumferential surface of the anvil shaft portion 10C.

[0092] The hammer protrusion 47B can come into contact with the anvil protrusion 10D. When the motor 6 is driven in a state in which the hammer protrusion 47B and the anvil protrusion 10D are in contact with each other, the anvil 10 rotates together with the hammer 47 and the spindle 8.

[0093] The anvil 10 is struck in the rotational direction by the hammer 47. For example, in a screw tightening operation, when the load acting on the anvil 10 becomes high, a situation may occur in which the anvil 10 cannot be rotated by the power generated by the motor 6 alone. When the anvil 10 cannot be rotated by the power generated by the motor 6 alone, the rotation of the anvil 10 and the hammer 47 stops. The spindle 8 and the hammer 47 can move relatively in the axial direction and the circumferential direction via the ball 48. Even if the rotation of the hammer 47 stops, the rotation of the spindle 8 continues by the power generated by the motor 6. When the spindle 8 rotates while the rotation of the hammer 47 is stopped, the ball 48 moves backward while being guided by each of the spindle groove 8D and the hammer groove 47A. The hammer 47 receives a force from the ball 48 and moves backward along with the ball 48. That is, the hammer 47 moves backward by the rotation of the spindle 8 while the rotation of the anvil 10 is stopped. As the hammer 47 moves rearward, the contact between the hammer projection 47B and the anvil projection 10D is released.

[0094] The coil spring 49 generates an elastic force that moves the hammer 47 forward. The hammer 47 that has moved backward moves forward due to the elastic force of the coil spring 49. When the hammer 47 moves forward, it receives a force in the rotational direction from the ball 48. That is, the hammer 47 moves forward while rotating. When the hammer 47 moves forward while rotating, the hammer protrusion 47B comes into contact with the anvil protrusion 10D while rotating. As a result, the anvil protrusion 10D is struck in the rotational direction by the hammer protrusion 47B. Both the power of the motor 6 and the inertial force of the hammer 47 act on the anvil 10. Therefore, the anvil 10 can rotate around the rotation axis AX with high torque.

[0095] The fan 12 rotates due to the rotational force of the motor 6. The fan 12 is disposed forward of the stator 26 of the motor 6. The fan 12 generates an airflow for cooling the motor 6. The fan 12 is fixed to at least a part of the rotor 27. The fan 12 is fixed to a front part of the rotor shaft 33 via a bush 12A. The fan 12 is disposed between the stator 26 and the rotor bearing 40. The fan 12 rotates due to the rotation of the rotor 27. As the rotor shaft 33 rotates, the fan 12 rotates together with the rotor shaft 33. As the fan 12 rotates, air in the external space of the housing 2 flows into the internal space of the housing 2 through the intake port 19. The air that has flowed into the internal space of the housing 2 circulates through the internal space of the housing 2, thereby cooling the motor 6. As the fan 12 rotates, the air that has circulated through the internal space of the housing 2 flows out through the exhaust port 20 into the external space of the housing 2.

[0096] The battery mounting section 13 is disposed below the battery holding section 23. The battery pack 25 is mounted to the battery mounting section 13. The battery pack 25 is detachable from the battery mounting section 13. The battery pack 25 functions as a power source for the impact wrench 1. The battery pack 25 includes a secondary battery. In the embodiment, the battery pack 25 includes a rechargeable lithium-ion battery. When mounted to the battery mounting section 13, the battery pack 25 can supply power to the impact wrench 1. The motor 6 and the light 17 are each driven based on the power supplied from the battery pack 25.

[0097] The trigger lever 14 is provided on the grip portion 22. The trigger lever 14 is operated by an operator to start the motor 6. By operating the trigger lever 14, the motor 6 is switched between being driven and being stopped.

[0098] The forward / reverse switching lever 15 is provided on the upper part of the grip portion 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 is switched from one of the forward direction and the reverse direction to the other. By switching the rotation direction of the motor 6, the rotation direction of the spindle 8 is switched.

[0099] The operation display unit 16 has a plurality of operation buttons 16A and a plurality of light emitting units 16B. When an operator operates the operation button 16A, the operation mode of the motor 6 is switched. The operation display unit 16 is provided in the battery holding unit 23. The operation display unit 16 is provided on the upper surface of the battery holding unit 23, further forward than the grip unit 22.

[0100] The light 17 emits illumination light. The light 17 illuminates the anvil 10 and the area around the anvil 10 with the illumination light. The light 17 illuminates the front of the anvil 10 with the illumination light. The light 17 also illuminates the socket 50 attached to the anvil 10 and the area around the socket 50 with the illumination light. The light 17 is disposed above the trigger lever 14.

[0101] The controller 18 outputs a control signal for controlling the motor 6. The controller 18 includes a board on which a plurality of electronic components are mounted. Examples of the electronic components mounted on the board include a processor such as a central processing unit (CPU), a non-volatile memory such as a read only memory (ROM) or storage, a volatile memory such as a random access memory (RAM), a transistor, and a resistor. The controller 18 is housed in a battery holding unit 23.

[0102] [Separation suppression mechanism] FIG. 6 is a cross-sectional view showing the front part of the upper part of the impact wrench 1 according to the embodiment. FIG. 7 is a vertical cross-sectional view showing the separation suppression mechanism 60 according to the embodiment. FIG. 8 is a horizontal cross-sectional view showing the separation suppression mechanism 60 according to the embodiment. FIG. 9 is a rear view of the separation suppression mechanism 60 according to the embodiment. FIG. 10 is a front view of the separation suppression mechanism 60 according to the embodiment. FIG. 11 is an exploded perspective view showing the separation suppression mechanism 60 according to the embodiment. FIG. 12 is a side view showing the separation suppression mechanism 60 according to the embodiment.

[0103] When at least a portion of the anvil 10 breaks, the separation suppression mechanism 60 prevents the front portion of the anvil 10 ahead of the broken portion from falling off. The anvil shaft portion 10C has a square column portion 10E to which the socket 50 is attached, and a cylindrical portion 10F supported by the anvil bearing 46. The front end portion of the cylindrical portion 10F is connected to the rear end portion of the square column portion 10E. In addition, a circumferential groove 10J is provided on the outer circumferential surface of the anvil shaft portion 10C. The circumferential groove 10J is formed so as to surround the rotation axis AX. The circumferential groove 10J is connected to the rear end portion of the cylindrical portion 10F. A lubricant is accommodated on the outside of the circumferential groove 10J.

[0104] The socket 50 has an operation hole 50A in which the head of a bolt or a nut is placed, and a connection hole 50B that is arranged around the rectangular column portion 10E. The socket 50 is attached to the anvil 10 by inserting the rectangular column portion 10E into the connection hole 50B.

[0105] Generally, the anvil 10 of the impact wrench 1 is likely to break at the boundary between the rear end of the square columnar portion 10E and the front end of the cylindrical portion 10F. The separation suppression mechanism 60 prevents the front portion of the anvil shaft portion 10C forward of the boundary between the rear end of the square columnar portion 10E and the front end of the cylindrical portion 10F from falling off when the boundary between the rear end of the square columnar portion 10E and the front end of the cylindrical portion 10F breaks.

[0106] The separation suppression mechanism 60 has a wire 61 disposed inside the anvil 10. A front portion of the wire 61 is connected to the rectangular column portion 10E. A rear portion of the wire 61 is held by a holding portion of the anvil 10 rearward of the rear end portion of the rectangular column portion 10E.

[0107] Inside the anvil 10, a passage hole 10G extending in the front-rear direction, a retaining hole 10A connected to the rear end of the passage hole 10G, and a recess 10B connected to the rear end of the retaining hole 10A are provided. An opening is provided at the front end of the passage hole 10G. The opening at the front end of the passage hole 10G is provided at the front end surface of the anvil shaft portion 10C. The front end of the retaining hole 10A is connected to the rear end of the passage hole 10G. The retaining hole 10A has a larger diameter than the passage hole 10G. That is, the inner diameter of the retaining hole 10A is larger than the inner diameter of the passage hole 10G. The front end of the recess 10B is connected to the rear end of the retaining hole 10A. The recess 10B has a larger diameter than the retaining hole 10A. That is, the inner diameter of the recess 10B is larger than the inner diameter of the retaining hole 10A. The central axis of the passage hole 10G, the central axis of the retaining hole 10A, and the central axis of the recess 10B coincide with each other.

[0108] 9, in a cross section perpendicular to the rotation axis AX, the shape of the inner edge of the passage hole 10G is rectangular. In a cross section perpendicular to the rotation axis AX, the shape of the inner edge of the holding hole 10A is circular. In a cross section perpendicular to the rotation axis AX, the shape of the inner edge of the recess 10B is circular.

[0109] In the embodiment, the holding portion that holds the rear portion of the wire 61 is the holding hole 10A. The rear portion of the wire 61 is held in the holding hole 10A. In the embodiment, the separation suppression mechanism 60 has a retaining member 62 that is connected to the rear portion of the wire 61. The rear portion of the wire 61 is held in the holding hole 10A via the retaining member 62.

[0110] Since the front portion of the wire 61 is connected to the rectangular column portion 10E and the rear portion of the wire 61 is held in the retaining hole 10A rearward of the rear end of the rectangular column portion 10E, even if the boundary between the rear end of the rectangular column portion 10E and the front end of the cylindrical portion 10F breaks, the wire 61 prevents the front portion of the anvil 10 from falling off. Since the wire 61 is disposed inside the anvil 10, even if the anvil 10 does not have a thin-walled portion, even if the anvil 10 does not have a thin-walled portion, the anvil 10 is prevented from falling off when the boundary between the rear end of the rectangular column portion 10E and the front end of the cylindrical portion 10F breaks. Since the anvil 10 does not have to have a thin-walled portion, a decrease in the strength of the anvil 10 is suppressed.

[0111] In the embodiment, a boundary surface 10H facing rearward is provided at the boundary between the rear end of the passage hole 10G and the front end of the retaining hole 10A. The front end surface of the retaining member 62 contacts the boundary surface 10H. Since the front end surface of the retaining member 62 contacts the boundary surface 10H, the retaining member 62 and the wire 61 are prevented from moving forward relative to the anvil 10.

[0112] In the embodiment, the retaining member 62 has a slide hole 62A in which the wire 61 is disposed. The retaining member 62 is movable relative to the wire 61. The separation suppression mechanism 60 has a stopper member 63 fixed to the rear end of the wire 61. The retaining member 62 has a recess recessed forward from the rear end surface of the retaining member 62. The stopper member 63 can be housed in the recess of the retaining member 62. The stopper member 63 suppresses the retaining member 62 from coming off rearward from the wire 61.

[0113] The front part of the wire 61 is connected to the rectangular column part 10E via a pin 65. In the embodiment, the wire 61 has a straight part 61A extending in the front-rear direction and a ring part 61B provided at the front end part of the straight part 61A. The wire 61 is formed by bending a part of a single wire material. The ring part 61B is formed by bending a tip part of the wire material. The separation suppression mechanism 60 has a crimping member 64 that fixes a part of the ring part 61B and the straight part 61A. After the tip part of the wire material is bent, the tip part of the wire material and a part of the wire material are fixed by the crimping member 64 to form the wire 61 having the ring part 61B and the straight part 61A. The straight part 61A is disposed in a slide hole 62A of the retaining member 62. The retaining member 62 is movable relative to the straight part 61A. The stopper member 63 is fixed to the rear end of the straight portion 61A and prevents the retaining member 62 from slipping out rearward from the straight portion 61A.

[0114] The anvil 10 has a pin hole 10K that connects the outer surface of the rectangular column portion 10E and the passage hole 10G. The socket 50 has a pin hole 50C that connects the outer surface of the rear of the socket 50 and the connection hole 50B. The pin 65 is inserted into each of the pin hole 50C, the pin hole 10K, and the ring portion 61B. By inserting the pin 65 into each of the pin hole 50C, the pin hole 10K, and the ring portion 61B, the socket 50, the rectangular column portion 10E, and the front portion of the wire 61 are connected.

[0115] The ring portion 61B is disposed in the passage hole 10G. In the embodiment, a positioning groove 10L in which at least a part of the ring portion 61B is disposed is provided on the inner surface of the passage hole 10G. The ring portion 61B and the anvil 10 are positioned by the positioning groove 10L.

[0116] In the embodiment, the position of the positioning groove 10L coincides with the position of at least a part of the pin hole 10K in the front-rear direction, thereby determining the position of the ring portion 61B and the pin hole 10K.

[0117] In the embodiment, the positioning groove 10L positions the ring portion 61B so that the central axis of the pin hole 10K and the central axis of the ring portion 61B coincide. That is, the positioning groove 10L positions the ring portion 61B so that the pin hole 10K and the central hole of the ring portion 61B coincide. This makes it easier to insert the pin 65 into each of the pin hole 10K and the ring portion 61B.

[0118] In the front-rear direction, the front end of the retaining hole 10A is disposed between the rear end and the front end of the cylindrical portion 10F and is disposed rearward of the center of the cylindrical portion 10F.

[0119] In the front-rear direction, the front end of the circumferential groove 10J is located rearward of the front end of the retaining hole 10A. In the front-rear direction, the rear end of the circumferential groove 10J is located forward of the rear end of the retaining hole 10A.

[0120] The protrusion 8E provided at the front end of the spindle 8 is inserted into the recess 10B. An O-ring 35 is provided to seal the boundary between the recess 10B and the protrusion 8E. The O-ring 35 prevents the lubricant around the spindle 8 from leaking out of the impact wrench 1 through the anvil 10.

[0121] In the embodiment, the shape of the inner edge of the passage hole 10G perpendicular to the rotation axis AX is substantially equal to the shape of the outer edge of the retaining member 62 perpendicular to the rotation axis AX. The dimension of the inner edge of the passage hole 10G perpendicular to the rotation axis AX is substantially equal to the dimension of the outer edge of the retaining member 62 perpendicular to the rotation axis AX. In detail, the dimension of the inner edge of the passage hole 10G perpendicular to the rotation axis AX is slightly larger than the dimension of the outer edge of the retaining member 62 perpendicular to the rotation axis AX so that the retaining member 62 can be lightly press-fitted into the passage hole 10G.

[0122] In the embodiment, the shape of the inner edge of the passage hole 10G and the shape of the outer edge of the retaining member 62 may each be rectangular.

[0123] The separation suppression mechanism 60, which includes the wire 61, the retaining member 62, the stopper member 63, and the crimping member 64, is inserted into the passage hole 10G from the opening at the front end of the passage hole 10G. After the retaining member 62 is inserted into the passage hole 10G from the opening at the front end of the passage hole 10G, it passes through the passage hole 10G and is accommodated in the retaining hole 10A.

[0124] In the embodiment, the shape of the inner edge of the passage hole 10G perpendicular to the rotation axis AX is substantially equal to the shape of the outer edge of the retaining member 62, and the dimensions of the inner edge of the passage hole 10G perpendicular to the rotation axis AX are substantially equal to the dimensions of the outer edge of the retaining member 62, so that the retaining member 62 is lightly press-fitted into the passage hole 10G from the opening at the front end of the passage hole 10G. The retaining member 62 passes rearward through the passage hole 10G while being lightly press-fitted into the passage hole 10G, and is then accommodated in the retaining hole 10A.

[0125] The retaining member 62, which passes rearward through the passage hole 10G while being lightly press-fitted into the passage hole 10G, has its rotational angle changed after it reaches the retaining hole 10A. That is, after the retaining hole 10A is reached, the separation suppression mechanism 60 is rotated about the rotation axis AX. The retaining member 62 is disposed in the retaining hole 10A at an angle different from the rotational angle when it passes through the passage hole 10G, so that the front end surface of the retaining member 62 comes into contact with the boundary surface 10H.

[0126] After the retaining hole 10A is accommodated in the retaining hole 10A, the probability that the outer edge of the retaining member 62 will coincide with the inner edge of the passage hole 10G is low. Therefore, the retaining member 62 accommodated in the retaining hole 10A is prevented from entering the passage hole 10G. In other words, the state in which all end faces of the retaining member 62 are in contact with the boundary surface 10H is maintained.

[0127] When the retaining member 62 reaches the retaining hole 10A, the ring portion 61B is disposed in the passage hole 10G. At least a portion of the ring portion 61B is disposed in the positioning groove 10L provided on the inner surface of the passage hole 10G. When at least a portion of the ring portion 61B is disposed in the positioning groove 10L, the ring portion 61B and the anvil 10 are positioned. After the ring portion 61B and the anvil 10 are positioned, the pin 65 is inserted into each of the pin hole 50C, the pin hole 10K, and the ring portion 61B. When the pin 65 is inserted into each of the pin hole 50C, the pin hole 10K, and the ring portion 61B, the socket 50, the rectangular column portion 10E, and the front portion of the wire 61 are connected.

[0128] [effect] As described above, in the embodiment, the impact wrench 1 may include the motor 6, the hammer 47 disposed forward of the motor 6 and rotated by the motor 6 about the rotation axis AX extending in the front-rear direction, the anvil 10 struck in the rotational direction by the hammer 47, the anvil bearing 46 rotatably supporting the anvil 10, and the wire 61 disposed inside the anvil 10. The anvil 10 may have a square column portion 10E to which the socket 50 is attached, and a cylindrical portion 10F connected to the rear end of the square column portion 10E and supported by the anvil bearing 46. The front portion of the wire 61 may be connected to the square column portion 10E. The rear portion of the wire 61 may be held in a holding hole 10A, which is a holding portion of the anvil 10, rearward of the rear end of the square column portion 10E.

[0129] In the above configuration, the front part of the wire 61 is connected to the square column part 10E, and the rear part of the wire 61 is held in the holding hole 10A, which is a holding part behind the rear end of the square column part 10E, so that even if the boundary between the rear end of the square column part 10E and the front end of the cylindrical part 10F breaks, the wire 61 prevents the front part of the anvil 10 from falling off. In general, the anvil 10 of the impact wrench 1 is likely to break at the boundary between the rear end of the square column part 10E and the front end of the cylindrical part 10F. Since the wire 61 is disposed inside the anvil 10, even if the anvil 10 does not have a thin-walled part, the front part of the anvil 10 is prevented from falling off when the boundary between the rear end of the square column part 10E and the front end of the cylindrical part 10F breaks. Since the anvil 10 does not need to have a thin-walled part, the strength of the anvil 10 is suppressed from decreasing.

[0130] In the embodiment, a passage hole 10G extending in the front-rear direction and a retaining hole 10A connected to a rear end of the passage hole 10G and having a larger diameter than the passage hole 10G may be provided inside the anvil 10. The impact wrench 1 may include a retaining member 62 connected to a rear portion of the wire 61. The rear portion of the wire 61 may be retained in the retaining hole 10A via the retaining member 62.

[0131] In the above configuration, the rear portion of the wire 61 is held in the holding hole 10A via the retaining member 62.

[0132] In the embodiment, a boundary surface 10H facing rearward may be provided at the boundary between the rear end of the passage hole 10G and the front end of the holding hole 10A. The front end surface of the retaining member 62 may contact the boundary surface 10H.

[0133] In the above configuration, the front end face of the retaining member 62 contacts the boundary surface 10H, so that the retaining member 62 and the wire 61 are prevented from moving forward relative to the anvil 10.

[0134] In the embodiment, the shape and dimensions of the inner edge of the passage hole 10G perpendicular to the rotation axis AX may be equal to the shape and dimensions of the outer edge of the retaining member 62 perpendicular to the rotation axis AX. The retaining member 62 may pass through the passage hole 10G and be housed in the retaining hole 10A.

[0135] In the above configuration, the shape of the inner edge of the passage hole 10G perpendicular to the rotation axis AX and the shape of the outer edge of the retaining member 62 are substantially equal. The dimensions of the inner edge of the passage hole 10G perpendicular to the rotation axis AX and the dimensions of the outer edge of the retaining member 62 are substantially equal. The retaining member 62 is lightly press-fitted into the passage hole 10G from the opening at the front end of the passage hole 10G. In a state where the retaining member 62 is lightly press-fitted into the passage hole 10G, the retaining member 62 passes through the passage hole 10G toward the rear and is then accommodated in the retaining hole 10A.

[0136] In the embodiment, the retaining member 62 may be disposed in the retaining hole 10A at an angle different from the angle of the rotation direction when passing through the passage hole 10G.

[0137] In the above configuration, the retaining member 62, which is lightly press-fitted into the passage hole 10G and passes rearward through the passage hole 10G, is accommodated in the retaining hole 10A and then has its angle of rotation changed, causing the front end surface of the retaining member 62 to come into contact with the boundary surface 10H.

[0138] In the embodiment, the outer edge of the retaining member 62 may be rectangular.

[0139] In the above configuration, the shape of the inner edge of the passage hole 10G and the shape of the outer edge of the retaining member 62 are both rectangular, so there is a low probability that the outer edge of the retaining member 62 housed in the retaining hole 10A will coincide with the inner edge of the passage hole 10G. This prevents the retaining member 62 housed in the retaining hole 10A from entering the passage hole 10G. The shape of the outer edge of the retaining member 62 may be a triangle, any polygon having pentagons or more, or an ellipse. The shape of the outer edge of the retaining member 62 may be any shape other than a circle.

[0140] In the embodiment, the front end of the retaining hole 10A may be disposed between the rear end and the front end of the cylindrical portion 10F in the front-rear direction.

[0141] In the above configuration, the length of the passage hole 10G in the front-rear direction is prevented from becoming excessively long.

[0142] In the embodiment, the front end of the retaining hole 10A may be located rearward of the center of the cylindrical portion 10F in the front-rear direction.

[0143] In the above configuration, the length of the passage hole 10G in the front-rear direction is prevented from becoming excessively short.

[0144] In an embodiment, a circumferential groove 10J connected to the rear end of the cylindrical portion 10F may be provided on the outer circumferential surface of the anvil 10. In the front-rear direction, the front end of the circumferential groove 10J may be located rearward of the front end of the retaining hole 10A.

[0145] In the above configuration, the length of the passage hole 10G in the front-rear direction is prevented from becoming excessively long.

[0146] In the embodiment, the rear end of the circumferential groove 10J may be disposed forward of the rear end of the retaining hole 10A in the front-rear direction.

[0147] In the above configuration, the length of the circumferential groove 10J in the front-rear direction is prevented from becoming excessively long.

[0148] In the embodiment, the impact wrench 1 may include a spindle 8 that supports the hammer 47. A recess 10B that is connected to the rear end of the retaining hole 10A and has a larger diameter than the retaining hole 10A may be provided inside the anvil 10. A protrusion 8E provided on the front end of the spindle 8 may be inserted into the recess 10B. The impact wrench 1 may include an O-ring 35 that seals the boundary between the recess 10B and the protrusion 8E.

[0149] In the above configuration, the lubricant around the spindle 8 is prevented from leaking out of the impact wrench 1 through the anvil 10.

[0150] In the embodiment, the retaining member 62 may have a slide hole 62A in which the wire 61 is disposed. The retaining member 62 may be movable relative to the wire 61. The impact wrench 1 may include a stopper member 63 fixed to the rear end of the wire 61 to prevent the retaining member 62 from slipping out rearward from the wire 61.

[0151] In the above configuration, the retaining member 62 is movable relative to the wire 61, which prevents a decrease in workability when the retaining member 62 is lightly press-fitted into the passage hole 10G. Also, since the retaining member 62 is movable relative to the wire 61, the stopper member 63 of the retaining member 62 is easy to assemble. Also, since the rectangular retaining member 62 can rotate (slide) when it comes out of the passage hole 10G, it is effective as a retainer.

[0152] In the embodiment, the front portion of the wire 61 may be connected to the rectangular column portion 10E via a pin 65.

[0153] In the above configuration, the front portion of the wire 61 is connected to the rectangular prism portion 10E via the pin 65, so that deterioration in workability when connecting the front portion of the wire 61 to the rectangular prism portion 10E is suppressed.

[0154] In an embodiment, the wire 61 may have a straight portion 61A extending in the front-rear direction and a ring portion 61B provided at the front end of the straight portion 61A. The anvil 10 may have a pin hole 10K connecting the outer surface of the rectangular column portion 10E and the passage hole 10G. The pin 65 may be inserted into each of the pin hole 10K and the ring portion 61B.

[0155] In the above configuration, the pin 65 is inserted into the pin hole 10K and the ring portion 61B, so that the front portion of the wire 61 and the rectangular column portion 10E are connected with good operability.

[0156] In the embodiment, the retaining member 62 may have a slide hole 62A in which the straight portion 61A is disposed. The retaining member 62 may be movable relative to the straight portion 61A. The impact wrench 1 may include a stopper member 63 fixed to the rear end of the straight portion 61A to prevent the retaining member 62 from coming off the wire 61 rearward.

[0157] In the above-described configuration, the retaining member 62 is movable relative to the straight portion 61A, so that a decrease in workability when the retaining member 62 is lightly press-fitted into the passage hole 10G is suppressed.

[0158] In the embodiment, the ring portion 61B may be formed by bending a tip portion of a wire material. The impact wrench 1 may include a crimping member 64 that fixes a part of the ring portion 61B and the straight portion 61A.

[0159] In the above configuration, the wire 61 having the ring portion 61B and the straight portion 61A is formed from a single wire material.

[0160] In the embodiment, a positioning groove 10L in which at least a portion of the ring portion 61B is disposed may be provided on the inner surface of the passage hole 10G.

[0161] In the above configuration, the ring portion 61B and the anvil 10 are positioned.

[0162] In an embodiment, the position of the positioning groove 10L may coincide with the position of at least a portion of the pin hole 10K in the front-rear direction.

[0163] In the above configuration, the ring portion 61B and the pin hole 10K are positioned.

[0164] In the embodiment, the positioning groove 10L may position the ring portion 61B so that the central axis of the pin hole 10K and the central axis of the ring portion 61B coincide with each other.

[0165] In the above configuration, the pin 65 can be easily inserted into the pin hole 10K and the ring portion 61B.

[0166] [Another embodiment] Fig. 13 is a perspective view showing a separation suppression mechanism 600 according to another embodiment. As shown in Fig. 13, the separation suppression mechanism 600 has a wire 61 having a straight portion 61A and a ring portion 61B, and a crimping member 64 that fixes a part of the ring portion 61B to the straight portion 61A. In the example shown in Fig. 13, a spring portion 61C is provided on a part of the straight portion 61A. The spring portion 61C is formed by winding a part of the straight portion 61A into a coil shape.

[0167] 13, when the boundary between the rear end of the rectangular prism portion 10E and the front end of the cylindrical portion 10F breaks, the tension applied to the wire 61 is absorbed by the elastic deformation of the spring portion 61C. This prevents excessive tension from being applied to the wire 61.

[0168] In the above-described embodiment, the power source for the impact wrench 1 does not have to be the battery pack 25, and may be a commercial power source (AC power source). [Explanation of symbols]

[0169] 1...impact wrench, 2...housing, 2H...screw boss portion, 2L...left housing, 2R...right housing, 2S...screw, 3...rear cover, 4...hammer case, 4A...rear cylinder portion, 4B...front cylinder portion, 4C...annular portion, 4H...screw boss portion, 5...screw, 6...motor, 7...reduction mechanism, 8...spindle, 8A...flange portion, 8B...spindle shaft portion, 8C...annular portion, 8D...spindle groove, 8E...projection portion, 9...impact mechanism, 10...anvil (output portion), 10A...retaining hole, 10B...recess, 10C...anvil shaft portion, 10D...anvil protrusion portion, 1 0E...rectangular column portion, 10F...cylindrical portion, 10G...passage hole, 10H...boundary surface, 10J...circumferential groove, 10K...pin hole, 10L...positioning groove, 11...ball, 12...fan, 12A...bushing, 13...battery mounting portion, 14...trigger lever, 15...forward / reverse switching lever, 16...operation display portion, 16A...operation button, 16B...light-emitting portion, 17...light, 18...controller, 19...air intake, 20...air exhaust, 21...motor housing portion, 22...grip portion, 23...battery holding portion, 24...bearing box, 25...battery pack, 26...stator, 27...rotor 28... stator core, 29... front insulator, 30... rear insulator, 31... coil, 32... rotor core, 33... rotor shaft, 34... rotor magnet, 35... O-ring, 36... seal member, 37... sensor board, 38... bus bar, 39... rotor bearing, 40... rotor bearing, 41... pinion gear, 42... planetary gear, 42P... pin, 43... internal gear, 44... spindle bearing, 45... washer, 46... anvil bearing, 46A... outer sleeve, 46B... inner sleeve, 47... hammer, 47A ...Hammer groove, 47B...Hammer protrusion portion, 47C...Recess portion, 47D...Body portion, 47E...Outer cylinder portion, 47G...Inner cylinder portion, 47H...Ball groove, 48...Ball, 49...Coil spring, 50...Socket, 50A...Operation hole, 50B...Connection hole, 50C...Pin hole, 51...Snap ring, 60...Separation suppression mechanism, 61...Wire, 61A...Straight portion, 61B...Ring portion, 61C...Spring portion, 62...Prevention member, 62A...Slide hole, 63...Stopper member, 64...Crimped member, 65...Pin, 400...Cover, 600...Separation suppression mechanism, AX...Rotating shaft.

Claims

1. A motor; a hammer disposed forward of the motor and rotated by the motor about a rotation shaft extending in the front-rear direction; an anvil that is struck in a rotational direction by the hammer; an anvil bearing that rotatably supports the anvil; a wire disposed inside the anvil; The anvil has a rectangular column portion to which a socket is attached, and a cylindrical portion connected to a rear end of the rectangular column portion and supported by the anvil bearing, The front portion of the wire is connected to the rectangular column portion, The rear portion of the wire is held by a holding portion of the anvil rearward of the rear end portion of the rectangular column portion. Impact wrench.

2. A passage hole extending in the front-rear direction and a retaining hole connected to a rear end of the passage hole and having a larger diameter than the passage hole are provided inside the anvil, a retaining member connected to a rear portion of the wire; The holding portion includes the holding hole, The rear portion of the wire is held in the holding hole via the retaining member.

2. The impact wrench according to claim 1.

3. a boundary surface facing rearward is provided at a boundary between a rear end of the passage hole and a front end of the retaining hole, The front end surface of the retaining member contacts the boundary surface.

3. The impact wrench according to claim 2.

4. a shape and a size of an inner edge of the passage hole perpendicular to the rotation shaft are equal to a shape and a size of an outer edge of the retaining member perpendicular to the rotation shaft; The retaining member passes through the passage hole and is accommodated in the retaining hole.

4. The impact wrench according to claim 3.

5. the retaining member is disposed in the retaining hole at an angle different from the angle of the rotation direction when passing through the passage hole; 5. The impact wrench according to claim 4.

6. The outer edge of the retaining member has a rectangular shape.

5. The impact wrench according to claim 4.

7. In the front-rear direction, a front end portion of the retaining hole is disposed between a rear end portion and a front end portion of the cylindrical portion.

3. The impact wrench according to claim 2.

8. In the front-rear direction, a front end portion of the retaining hole is disposed rearward of a center portion of the cylindrical portion.

8. The impact wrench according to claim 7.

9. A circumferential groove connected to the rear end of the cylindrical portion is provided on the outer circumferential surface of the anvil, a front end portion of the circumferential groove is disposed rearward of a front end portion of the retaining hole in a front-rear direction; 8. The impact wrench according to claim 7.

10. a rear end portion of the circumferential groove is disposed forward of a rear end portion of the retaining hole in the front-rear direction; 10. The impact wrench according to claim 9.

11. A spindle supporting the hammer is provided. A recess is provided inside the anvil, the recess being connected to a rear end of the retaining hole and having a diameter larger than that of the retaining hole, A protrusion provided on the front end of the spindle is inserted into the recess, An O-ring is provided to seal the boundary between the recess and the protrusion.

3. The impact wrench according to claim 2.

12. The retaining member has a slide hole in which the wire is disposed and is movable relative to the wire, a stopper member fixed to a rear end of the wire to prevent the retaining member from slipping out rearward from the wire; 5. The impact wrench according to claim 4.

13. The front portion of the wire is connected to the rectangular column portion via a pin.

3. The impact wrench according to claim 2.

14. The wire has a straight portion extending in a front-rear direction and a ring portion provided at a front end of the straight portion, the anvil has a pin hole connecting an outer surface of the rectangular column portion and the passage hole, The pin is inserted into each of the pin hole and the ring portion.

14. The impact wrench of claim 13.

15. the retaining member has a slide hole in which the straight portion is disposed and is movable relative to the straight portion, a stopper member fixed to a rear end of the straight portion to prevent the retaining member from being pulled out rearward from the wire; 15. The impact wrench of claim 14.

16. The ring portion is formed by bending a tip portion of a wire material, a crimping member that fixes a part of the ring portion and the straight portion; 15. The impact wrench of claim 14.

17. A positioning groove in which at least a part of the ring portion is disposed is provided on an inner surface of the passage hole.

17. The impact wrench of claim 16.

18. In the front-rear direction, the position of the positioning groove coincides with the position of at least a part of the pin hole.

18. The impact wrench of claim 17.

19. The positioning groove positions the ring portion so that a central axis of the pin hole and a central axis of the ring portion coincide with each other.

19. The impact wrench of claim 18.

20. A spring portion is provided on a part of the straight portion.

15. The impact wrench of claim 14.

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