Impact tool and manufacturing method for impact wrench

Abstract

To prevent leakage of a lubricant existing inside a hammer case.SOLUTION: An impact tool includes: a motor having a rotor; a striking mechanism rotated by the rotor; an anvil struck by the striking mechanism; a hammer case having an opening; an anvil bearing fixed to the hammer case inside the hammer case and supporting the anvil; a seal member disposed between the anvil bearing and the anvil, in the hammer case; and a support member disposed to face the opening and capable of supporting the seal member from front.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The technology disclosed herein relates to a method for manufacturing an impact tool and an impact wrench. [Background technology]

[0002] BACKGROUND ART In the technical field related to impact tools, an impact wrench such as that disclosed in Patent Document 1 is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-187700 A Summary of the Invention [Problem to be solved by the invention]

[0004] The impact tool includes an anvil that is struck by a striking mechanism, and a hammer case that houses at least a portion of the anvil and the striking mechanism. Lubricant present inside the hammer case may leak out from an opening at the front end of the hammer case.

[0005] The technology disclosed in this specification aims to suppress leakage of lubricant present inside the hammer case. [Means for solving the problem]

[0006] The present specification discloses an impact tool. The impact tool may include a motor having a rotor, a striking mechanism rotated by the rotor, an anvil struck by the striking mechanism, a hammer case having an opening, an anvil bearing fixed to the hammer case inside the hammer case and supporting the anvil, a seal member disposed inside the hammer case between the anvil bearing and the anvil, and a support member disposed facing the opening and capable of supporting the seal member from the front. The inner diameter of the support member may be smaller than the inner diameter of the opening. [Effects of the Invention]

[0007] According to the technology disclosed in this specification, leakage of lubricant present inside the hammer case is suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of an impact tool according to an embodiment, seen from the front right. [Figure 2] FIG. 2 is a side view showing the impact tool according to the embodiment. [Figure 3] FIG. 3 is a vertical cross-sectional view showing an upper portion of the impact tool according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the upper part of the impact tool according to the embodiment. [Figure 5] FIG. 5 is an enlarged longitudinal sectional view of a part of the impact tool according to the embodiment. [Figure 6] FIG. 6 is an exploded perspective view showing the impact tool according to the embodiment, seen from the front right. [Figure 7] FIG. 7 is a perspective view of the anvil according to the embodiment, seen from the front right. [Figure 8] FIG. 8 is a side view showing the anvil according to the embodiment. [Figure 9] FIG. 9 is a front view of the anvil according to the embodiment. [Figure 10] FIG. 10 is an enlarged view of a portion of the anvil according to the embodiment. [Figure 11] FIG. 11 is an enlarged longitudinal cross-sectional view of a portion of the second impact wrench according to the embodiment. [Figure 12] FIG. 12 is an enlarged longitudinal sectional view of a portion of an impact tool according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] In one or more embodiments, the impact tool may include a motor having a rotor, a striking mechanism rotated by the rotor, an anvil struck by the striking mechanism, a hammer case having an opening, an anvil bearing fixed to the hammer case inside the hammer case and supporting the anvil, a seal member disposed inside the hammer case between the anvil bearing and the anvil, and a support member disposed facing the opening and capable of supporting the seal member from the front. The inner diameter of the support member may be smaller than the inner diameter of the opening.

[0010] In the above configuration, the sealing member prevents lubricant present inside the hammer case from leaking to the outside of the hammer case through the opening of the hammer case. The sealing member also prevents foreign matter from the outside of the hammer case from entering the inside of the hammer case through the opening of the hammer case. The support member prevents the sealing member from coming off the opening of the hammer case. Furthermore, because the inner diameter of the support member is smaller than the inner diameter of the hammer case, the support member prevents the leakage of lubricant and the intrusion of foreign matter. Furthermore, even if the size of the opening of the hammer case is changed, for example, simply by changing the support member to match the change in the size of the opening of the hammer case, the sealing member is prevented from coming off, thereby preventing the leakage of lubricant and the intrusion of foreign matter.

[0011] In one or more embodiments, the support member may oppose the seal member.

[0012] In the above configuration, the support member can prevent the seal member from slipping out of the opening of the hammer case.

[0013] In one or more embodiments, the support member may be disposed around at least a portion of the periphery of the anvil.

[0014] In the above configuration, the support member can stably support the seal member.

[0015] In one or more embodiments, the support member may include a washer disposed around the anvil.

[0016] In the above configuration, the washer can come into contact with the seal member with a uniform force, thereby preventing a large force from being applied locally to the seal member.

[0017] In one or more embodiments, at least a portion of the seal member may contact the anvil, and the support member may be spaced from the anvil.

[0018] In the above configuration, the support member is spaced apart from the anvil, allowing the anvil to rotate smoothly.

[0019] In one or more embodiments, the support member may be fixed to at least one of the hammer case and the anvil bearing.

[0020] In the above configuration, changes in the relative positions of the support member, the hammer case, and the anvil bearing are suppressed.

[0021] In one or more embodiments, the support member may be sandwiched between the anvil bearing and a portion of the hammer case in the front-to-rear direction.

[0022] With the above-described configuration, changes in the relative positions of the support member, hammer case, and anvil bearing are suppressed, and the impact tool is easy to assemble.

[0023] In one or more embodiments, the seal member may be supported on an anvil bearing.

[0024] In the above configuration, changes in the relative positions of the support member and the anvil bearing are suppressed.

[0025] 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 tool 1. The impact tool 1 has a motor 6 as a power source.

[0026] In the embodiment, the direction parallel to the rotation axis AX of the motor 6 is referred to as the axial direction, the direction circumferentially around the rotation axis AX is referred to as the circumferential direction or rotation direction, and the radial direction of the rotation axis AX is referred to as the radial direction.

[0027] The rotation axis AX extends in the front-to-rear direction. One axial side is the front, and the other axial side is the rear. In addition, in the radial direction, a position closer to or approaching the rotation axis AX will be referred to as the radially inner side, and a position farther from or away from the rotation axis AX will be referred to as the radially outer side.

[0028] [Impact tools] FIG. 1 is a perspective view of the impact tool 1 according to the embodiment, seen from the right front. FIG. 2 is a side view of the impact tool 1 according to the embodiment. FIG. 3 is a vertical cross-sectional view of the upper part of the impact tool 1 according to the embodiment. FIG. 4 is a horizontal cross-sectional view of the upper part of the impact tool 1 according to the embodiment. FIG. 5 is a vertical cross-sectional view of an enlarged portion of the impact tool 1 according to the embodiment. FIG. 6 is an exploded perspective view of the impact tool 1 according to the embodiment, seen from the right front.

[0029] In the embodiment, the impact tool 1 is an impact wrench. The impact tool 1 includes a housing 2, a hammer case 4, a cover 3, a motor 6, a reduction mechanism 7, a spindle 8, a striking mechanism 9, an anvil 10, a fan 12, a battery mounting portion 13, a trigger lever 14, a forward / reverse rotation switching lever 15, an operation display portion 16, a light 17, a sealing member 70, and a support member 80.

[0030] 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 located to the right of the left housing 2L. The left housing 2L and the right housing 2R are fixed together with a plurality of screws 2S. The housing 2 is made up of a pair of split housing halves.

[0031] The housing 2 has a motor accommodating portion 21, a grip portion 22, and a battery holding portion 23.

[0032] The motor housing portion 21 houses the motor 6. The motor housing portion 21 and the hammer case 4 are fixed together by a plurality of screws 2T.

[0033] The grip portion 22 is held by an operator and extends downward from the motor housing portion 21. The trigger lever 14 is provided on the upper portion of the grip portion 22.

[0034] The battery holding portion 23 holds the battery pack 25 via the battery attachment portion 13. The battery holding portion 23 is connected to the lower end of the grip portion 22. The external dimensions of the battery holding portion 23 are larger than the external dimensions of the grip portion 22 in both the front-rear and left-right directions.

[0035] The motor accommodating section 21 has an intake port 19 and an exhaust port 20. The exhaust port 20 is provided forward of the intake port 19. Air in the external space of the housing 2 flows into the internal space of the housing 2 through the intake port 19. Air in the internal space of the housing 2 flows out to the external space of the housing 2 through the exhaust port 20.

[0036] The hammer case 4 houses a part of the reduction mechanism 7. The hammer case 4 houses a part of the spindle 8. The hammer case 4 houses the striking mechanism 9. The hammer case 4 houses a part of the anvil 10. A part of the reduction mechanism 7 and a part of the spindle 8 are disposed inside the bearing box 24. The reduction mechanism 7 includes a plurality of gears.

[0037] The hammer case 4 is made of metal. In this embodiment, the hammer case 4 is made of aluminum. The hammer case 4 is cylindrical. The hammer case 4 is disposed in front of the motor accommodating portion 21. A bearing box 24 is inserted inside the hammer case 4.

[0038] The cover 3 is disposed so as to cover at least a portion of the outer surface of the hammer case 4. In the embodiment, the cover 3 covers the front portion of the outer surface of the hammer case 4.

[0039] The motor 6 is a power source for the impact tool 1. 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 fixed to the motor housing 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 around a rotation axis AX extending in the front-rear direction.

[0040] The reduction mechanism 7 connects the rotor 27 and the spindle 8. 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 27. The reduction mechanism 7 is disposed forward of the motor 6. The reduction mechanism 7 includes a planetary gear mechanism. The reduction mechanism 7 has a plurality of gears. The gears of the reduction mechanism 7 are rotated by the rotor 27.

[0041] The spindle 8 rotates by the rotational force of the rotor 27 transmitted by the reduction mechanism 7. 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 on the front side of the reduction mechanism 7. The spindle 8 is disposed on the rear side of the anvil 10.

[0042] 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 rotational force of the motor 6 is transmitted to the striking mechanism 9 via the reduction mechanism 7 and the spindle 8.

[0043] The anvil 10 is an output shaft of the impact tool 1 that rotates based on the rotational force of the rotor 27. The anvil 10 is disposed forward of the motor 6. A socket, which is a type of tool tip, is attached to the front end of the anvil 10. The anvil 10 is disposed forward of at least a portion of the spindle 8.

[0044] The fan 12 generates an airflow for cooling the motor 6. The fan 12 is disposed forward of the stator 26 of the motor 6. The fan 12 is fixed to at least a portion of the rotor 27. As the fan 12 rotates, air from the external space of the motor accommodating section 21 flows into the internal space of the motor accommodating section 21 through the air intake port 19. The air that has flowed into the internal space of the motor accommodating section 21 cools the motor 6 by circulating through the internal space of the motor accommodating section 21. As the fan 12 rotates, the air that has circulated through the internal space of the motor accommodating section 21 flows out into the external space of the motor accommodating section 21 through the air exhaust port 20.

[0045] The battery attachment section 13 is connected to the battery pack 25. The battery pack 25 is attached to the battery attachment section 13. The battery pack 25 is detachable from the battery attachment section 13. The battery attachment section 13 is disposed below the battery holding section 23. The battery pack 25 is attached to the battery attachment section 13 by being inserted into the battery attachment section 13 from the front of the battery holding section 23. The battery pack 25 is removed from the battery attachment section 13 by being pulled forward from the battery attachment section 13. The battery pack 25 includes a secondary battery. In the embodiment, the battery pack 25 includes a rechargeable lithium-ion battery. When attached to the battery attachment section 13, the battery pack 25 can supply power to the impact tool 1. The motor 6 is driven by the power supplied from the battery pack 25.

[0046] The trigger lever 14 is operated by an operator to start the motor 6. Operating the trigger lever 14 switches between driving and stopping the motor 6. The trigger lever 14 is provided on the grip portion 22.

[0047] 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. The forward / reverse switching lever 15 is provided on the upper part of the grip portion 22.

[0048] The operation display unit 16 has a plurality of operation buttons 16A and an indicator display 16B. The operation mode of the motor 6 is switched when the operator operates the operation button 16A. The indicator display 16B has a plurality of light-emitting elements. The indicator display 16B displays the operation mode of the motor 6 by changing the lighting pattern of the plurality of light-emitting elements. The operation display unit 16 is provided in the battery holding unit 23. The operation display unit 16 is provided on the top surface of the battery holding unit 23, further forward than the grip unit 22.

[0049] 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 area in front of the anvil 10 with the illumination light. The light 17 also illuminates the tool attachment attached to the anvil 10 and the area around the tool attachment with the illumination light. The light 17 is disposed above the trigger lever 14.

[0050] The hammer case 4 has a first cylindrical portion 401, a second cylindrical portion 402, a case connecting portion 403, a third cylindrical portion 404, and a fourth cylindrical portion 405. The first cylindrical portion 401 is arranged around the striking mechanism 9. The second cylindrical portion 402 is arranged forward of the first cylindrical portion 401. The outer diameter of the second cylindrical portion 402 is smaller than the outer diameter of the first cylindrical portion 401. The case connecting portion 403 is arranged so as to connect the front portion of the first cylindrical portion 401 and the rear portion of the second cylindrical portion 402. The third cylindrical portion 404 is arranged forward of the second cylindrical portion 402. The fourth cylindrical portion 405 is arranged forward of the third cylindrical portion 404. The inner diameter of the second cylindrical portion 402 is smaller than the inner diameter of the first cylindrical portion 401. The inner diameter of the third cylindrical portion 404 is smaller than the inner diameter of the second cylindrical portion 402. The inner diameter of the fourth cylindrical portion 405 is smaller than the inner diameter of the third cylindrical portion 404 .

[0051] As shown in FIG. 5, the second cylindrical portion 402 has a rear surface 402R facing rearward and an inner circumferential surface 402S facing radially inward. The third cylindrical portion 404 has a rear surface 404R facing rearward and an inner circumferential surface 404S facing radially inward. The fourth cylindrical portion 405 has a rear surface 405R facing rearward and an inner circumferential surface 405S facing radially inward. The front end of the inner circumferential surface 402S is connected to the radial outer end of the rear surface 404R. The front end of the inner circumferential surface 404S is connected to the radial outer end of the rear surface 405R. The inner circumferential surface 405S defines an opening of the hammer case 4 provided at the front end of the hammer case 4.

[0052] The motor 6 has a stator 26 and a rotor 27. The stator 26 has a stator core 28, a front insulator 29, a rear insulator 30, and a coil 31. The rotor 27 rotates about a rotation axis AX. The rotor 27 has a rotor core 32, a rotor shaft 33, and a rotor magnet 34.

[0053] 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.

[0054] The front insulator 29 is provided in the front portion of the stator core 28. The rear insulator 30 is provided in the rear portion 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 arranged so as to cover part of the surface of the teeth. The rear insulator 30 is arranged so as to cover part of the surface of the teeth.

[0055] 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 plurality of coils 31 are connected via a bus bar unit 38.

[0056] The rotor core 32 and the rotor shaft 33 are both made of steel. The rotor shaft 33 is disposed inside the rotor core 32. The rotor core 32 and the rotor shaft 33 are fixed together. The front end of the rotor shaft 33 protrudes forward from the front end surface of the rotor core 32, and the rear end of the rotor shaft 33 protrudes rearward from the rear end surface of the rotor core 32.

[0057] The rotor magnet 34 is fixed to the rotor core 32. The rotor magnet 34 is disposed inside the rotor core 32.

[0058] A sensor board 37 is attached to the rear insulator 30. The sensor board 37 has a disk-shaped circuit board with a hole in the center and a rotation detection element supported by the circuit board. At least a portion of the sensor board 37 faces the rotor magnet 34. The rotation detection element detects the position of the rotor magnet 34 of the rotor 27, thereby detecting the position of the rotor 27 in the rotational direction.

[0059] The rotor shaft 33 is rotatably supported by rotor bearings 39. The rotor bearings 39 include a front rotor bearing 39F that rotatably supports the front end of the rotor shaft 33, and a rear rotor bearing 39R that rotatably supports the rear end of the rotor shaft 33.

[0060] The front rotor bearing 39F is held in the bearing box 24. The bearing box 24 has a recess 241 recessed forward from the rear surface of the bearing box 24. The front rotor bearing 39F is disposed in the recess 241. The rear rotor bearing 39R is held at the rear of the motor accommodating portion 21. The front end of the rotor shaft 33 is disposed in the internal space of the hammer case 4 through an opening in the bearing box 24.

[0061] The fan 12 is fixed to the front of the rotor shaft 33. The fan 12 is disposed between the front rotor bearing 39F and the stator 26. The fan 12 rotates due to the rotation of the rotor shaft 33. As the rotor shaft 33 rotates, the fan 12 rotates together with the rotor shaft 33.

[0062] 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 mechanism 7. The rotor shaft 33 is connected to the reduction mechanism 7 via the pinion gear 41.

[0063] 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 hammer case 4. Each of the plurality of planetary gears 42 meshes with the pinion gear 41. The planetary gear 42 is rotatably supported on 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 hammer case 4. The internal gear 43 is always non-rotatable relative to the hammer case 4.

[0064] 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.

[0065] The spindle 8 rotates due to the rotational force of the motor 6. The spindle 8 transmits the rotational force of the motor 6 to the anvil 10 via the striking mechanism 9. The spindle 8 has a spindle shaft portion 801 and a flange portion 802 provided at the rear of the spindle shaft portion 801. The planetary gear 42 is rotatably supported on the flange portion 802 via a pin 42P. The rotation axis of the spindle 8 coincides with the rotation axis AX of the motor 6. The spindle 8 rotates around the rotation axis AX. The spindle 8 is rotatably supported by a spindle bearing 44. A protrusion 803 is provided at the rear end of the spindle 8. The protrusion 803 protrudes rearward from the flange portion 802. The spindle bearing 44 is arranged to surround the protrusion 803.

[0066] The bearing box 24 is disposed around at least a portion of the periphery of the spindle 8. The spindle bearing 44 is held in the bearing box 24. The bearing box 24 has a recess 242 recessed from the front surface of the bearing box 24 to the rear. The spindle bearing 44 is disposed in the recess 242.

[0067] The striking mechanism 9 has a hammer 47, a hammer ball 48, a coil spring 50, and a washer 61. The striking mechanism 9 including the hammer 47, the hammer ball 48, the coil spring 50, and the washer 61 is housed in a first cylindrical portion 401 of the hammer case 4. The first cylindrical portion 401 is disposed around the hammer 47.

[0068] The hammer 47 is disposed forward of the speed reduction mechanism 7. The hammer 47 is disposed around the spindle shaft portion 801. The hammer 47 is supported by the spindle shaft portion 801.

[0069] 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.

[0070] The hammer 47 has a base portion 471 , a rear ring portion 473 , a support ring portion 474 , and a hammer protrusion portion 475 .

[0071] The base portion 471 is disposed around the spindle shaft portion 801. The base portion 471 is annular. The spindle shaft portion 801 is disposed inside the base portion 471.

[0072] The rear ring portion 473 protrudes rearward from the outer periphery of the base portion 471. The rear ring portion 473 is cylindrical. A rear end portion of the rear ring portion 473 is disposed rearward of a rear end portion of the support ring portion 474.

[0073] The support ring portion 474 protrudes rearward from the inner periphery of the base portion 471. The support ring portion 474 is cylindrical. The support ring portion 474 is disposed around the spindle shaft portion 801. The support ring portion 474 is supported by the spindle shaft portion 801 via the hammer ball 48. The support ring portion 474 has a large diameter portion 474A and a small diameter portion 474B disposed rearward of the large diameter portion 474A. The outer diameter of the large diameter portion 474A is larger than the outer diameter of the small diameter portion 474B. A step portion 474C is provided at the boundary between the large diameter portion 474A and the small diameter portion 474B.

[0074] The hammer protrusions 475 protrude forward from the front surface of the base portion 471. The front surface of the hammer protrusions 475 is disposed forward of the front surface of the base portion 471. Two hammer protrusions 475 are disposed in the circumferential direction.

[0075] A recess 476 is formed by the rear surface of the base portion 471, the inner peripheral surface of the rear ring portion 473, and the outer peripheral surface of the support ring portion 474. The recess 476 is provided in the rear portion of the hammer 47. The recess 476 is formed so as to be recessed forward from the rear surface of the hammer 47.

[0076] The hammer ball 48 is made of metal such as steel. The hammer ball 48 is disposed between the spindle shaft portion 801 and the hammer 47. The spindle 801 has a spindle groove 804 in which at least a portion of the hammer ball 48 is disposed. The spindle groove 804 is provided on a portion of the outer circumferential surface of the spindle shaft portion 801. The hammer 47 has a hammer groove 477 in which at least a portion of the hammer ball 48 is disposed. The hammer groove 477 is provided on a portion of the inner circumferential surface of the support ring portion 474. The hammer ball 48 is disposed between the spindle groove 804 and the hammer groove 477. The hammer ball 48 can roll inside the spindle groove 804 and inside the hammer groove 477. The hammer 47 is movable along with the hammer 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 804 and the hammer groove 477 .

[0077] The coil spring 50 is arranged around the spindle shaft portion 801. In the embodiment, the coil spring 50 includes a first coil spring 51 and a second coil spring 52 arranged in parallel with each other. The second coil spring 52 is arranged radially inward of the first coil spring 51. In the embodiment, the spring constant of the first coil spring 51 is greater than the spring constant of the second coil spring 52. The wire diameter of the first coil spring 51 is greater than the wire diameter of the second coil spring 52.

[0078] The rear end portions of the first coil springs 51 and the second coil springs 52 are supported on the front surface of the flange portion 802. The rear end portions of the first coil springs 51 contact the front surface of the flange portion 802. The rear end portions of the second coil springs 52 are supported on the front surface of the flange portion 802 via washers 62.

[0079] The front end of the first coil spring 51 and the front end of the second coil spring 52 are disposed inside the recess 476. A washer 61 is disposed inside the recess 476. The front end of the first coil spring 51 and the front end of the second coil spring 52 are supported by the washer 61. The washer 61 is a ring-shaped member. Each of the first coil spring 51 and the second coil spring 52 constantly generates an elastic force that moves the hammer 47 forward.

[0080] The washer 61 is disposed rearward of the base portion 471. The washer 61 supports the front ends of the first coil spring 51 and the second coil spring 52. In the radial direction, the washer 61 is disposed between the rear ring portion 473 and the support ring portion 474. The washer 61 is disposed inside the recess 476. The washer 61 is supported by the hammer 47 via a plurality of support balls 54. When the hammer 47 is disposed at the frontmost position within the movable range of the hammer 47 in the front-rear direction, the support balls 54 are disposed forward of the rear end of the hammer ball 48.

[0081] The support ball 54 is disposed in a support groove 478 provided in the hammer 47 inside the recess 476. In this embodiment, the support groove 478 is provided in the rear surface of the base portion 471. The support groove 478 is provided in a ring shape so as to surround the rotation axis AX. The support ball 54 supports the washer 61.

[0082] The washer 61 is sandwiched between the coil spring 50 and the support ball 54 in the front-rear direction. The washer 61 is spaced apart from the hammer 47 and the spindle 8.

[0083] The anvil 10 has an anvil shaft portion 101 , an anvil protrusion portion 102 , and a recess portion 103 .

[0084] The anvil shaft portion 101 extends in the axial direction (front-rear direction). The anvil shaft portion 101 is disposed forward of the spindle 8 and the hammer 47. At least a portion of the anvil shaft portion 101 is disposed in an opening provided at the front end of the hammer case 4. As described above, the opening at the front end of the hammer case 4 is defined by the inner circumferential surface 405S of the fourth cylindrical portion 405. The front end of the anvil shaft portion 101 protrudes forward from the opening of the hammer case 4. A socket, which is a type of tool, is attached to the front end of the anvil shaft portion 101.

[0085] The anvil protrusion 102 protrudes radially outward from the rear end of the anvil shaft portion 101. The anvil protrusion 102 is struck in the rotational direction by the hammer protrusion 475. A washer 53 is disposed between the front surface of the anvil protrusion 102 and the rear surface 402R of the second cylindrical portion 402. The washer 53 prevents contact between the anvil protrusion 102 and the second cylindrical portion 402. The rear end of the second cylindrical portion 402 receives the load of the anvil protrusion 102 via the washer 53.

[0086] The recess 103 is provided so as to recess forward from the center of the rear surface of the anvil 10. The front end of the spindle 8 is disposed in the recess 103.

[0087] The base portion 471 is disposed rearward of the anvil protrusion 102. The rear surface of the anvil protrusion 102 and the front surface of the base portion 471 are in contact with or spaced apart from each other.

[0088] 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 coincident. The anvil 10 rotates around the rotation axis AX. The anvil bearing 46 is disposed around the anvil shaft portion 101. A portion of the anvil bearing 46 is disposed inside the second cylindrical portion 402 of the hammer case 4. A portion of the anvil bearing 46 is disposed inside the third cylindrical portion 404 of the hammer case 4. The anvil bearing 46 is held in the second cylindrical portion 402 of the hammer case 4. The anvil bearing 46 is press-fitted into the second cylindrical portion 402. The anvil bearing 46 is fixed to the hammer case 4 inside the hammer case 4. The anvil bearing 46 rotatably supports the anvil shaft portion 101.

[0089] In the embodiment, the anvil bearing 46 is an iron sleeve. As shown in FIG. 5 , the anvil bearing 46 has an outer annular portion 461, a rear support portion 462, a front support portion 463, a rear convex portion 464, and a front convex portion 465. The rear support portion 462 protrudes radially inward from a rear portion of the outer annular portion 461. The front support portion 463 protrudes radially inward from a front portion of the outer annular portion 461. The rear convex portion 464 protrudes rearward from the rear support portion 462. The front convex portion 465 protrudes forward from the front support portion 463. A recess 466 of the anvil bearing 46 is defined by the outer annular portion 461, the rear support portion 462, and the front support portion 463.

[0090] The outer annular portion 461 has a front surface 461F facing forward, a rear surface 461R facing rearward, an inner peripheral surface 461S facing radially inward, and an outer peripheral surface 461T facing radially outward.

[0091] The rear support portion 462 has a front surface 462F facing forward and an inner circumferential surface 462S facing radially inward.

[0092] The front support portion 463 has a front surface 463F facing forward, a rear surface 463R facing rearward, and an inner circumferential surface 463S facing radially inward.

[0093] The rear convex portion 464 has a rear surface 464R facing rearward and an outer circumferential surface 464T facing radially outward.

[0094] The front convex portion 465 has a front surface 465F facing forward, an inner circumferential surface 465S facing radially inward, and an outer circumferential surface 465T facing radially outward.

[0095] An outer peripheral surface 461T of the outer annular portion 461 contacts an inner peripheral surface 402S of the second cylindrical portion 402. The inner peripheral surface 461S of the outer annular portion 461 is spaced apart from the outer peripheral surface of the anvil shaft portion 101. The recess 466 is defined by the inner peripheral surface 461S of the outer annular portion 461, a front surface 462F of the rear support portion 462, and a rear surface 463R of the front support portion 463.

[0096] As will be described later, the anvil shaft portion 101 has a rear cylindrical portion 112, a front cylindrical portion 114, and a recessed portion 113. An inner peripheral surface 461S of the outer ring portion 461 faces the outer peripheral surface of the recessed portion 113. An inner peripheral surface 462S of the rear support portion 462 contacts the outer peripheral surface of the rear cylindrical portion 112. An inner peripheral surface 463S of the front support portion 463 contacts the outer peripheral surface of the front cylindrical portion 114.

[0097] The radially outer outer edge of the front surface of the washer 53 faces the rear surface 402R of the second cylindrical portion 402. The radially inner inner edge of the front surface of the washer 53 faces the rear surface 461R of the outer annular portion 461. The radially inner inner circumferential surface of the washer 53 faces the outer circumferential surface 464T of the rear convex portion 464. The rear surface 464R of the rear convex portion 464 faces the front surface of the anvil protrusion 102 via a gap. The front surface 461F of the outer annular portion 461 faces the rear surface 404R of the third cylindrical portion 404. The outer circumferential surface 465T of the front convex portion 465 contacts the inner circumferential surface 404S of the third cylindrical portion 404.

[0098] The hammer protrusion 475 can come into contact with the anvil protrusion 102 in the rotational direction. When the motor 6 rotates while the hammer 47 and the anvil protrusion 102 are in contact with each other in the rotational direction, the anvil 10 rotates together with the hammer 47 and the spindle 8.

[0099] The anvil 10 is struck in the rotational direction by the hammer 47. For example, during a bolt tightening operation, if the load acting on the anvil 10 becomes too high, a situation may arise in which the anvil 10 cannot be rotated by the load of the coil spring 50 alone. When the load of the coil spring 50 alone cannot rotate the anvil 10, the rotation of the anvil 10 and the hammer 47 stops. The spindle 8 and the hammer 47 are capable of relative movement in the axial and circumferential directions via the hammer ball 48. Even when the rotation of the hammer 47 stops, the rotation of the spindle 8 continues due to the power generated by the motor 6. When the spindle 8 rotates while the rotation of the hammer 47 is stopped, the hammer ball 48 moves rearward while being guided by the spindle groove 804 and the hammer groove 477. The hammer 47 receives force from the hammer ball 48 and moves rearward along with the hammer ball 48. That is, the hammer 47 moves rearward by rotating the spindle 8 while the rotation of the anvil 10 is stopped. When the hammer 47 moves rearward, the contact between the hammer 47 and the anvil protrusion 102 is released.

[0100] When the hammer 47 moves rearward, the hammer 47 rotates relative to the spindle shaft portion 801. The washer 61 is spaced apart from the hammer 47 and the spindle 8. Therefore, the rotation of the hammer 47 is not hindered by the washer 61. In addition, the support ball 54 is disposed between the washer 61 and the hammer 47. The rotation of the support ball 54 allows the hammer 47 to rotate smoothly.

[0101] As described above, the coil spring 50 constantly generates an elastic force that moves the hammer 47 forward. After moving backward, the hammer 47 moves forward due to the elastic force of the coil spring 50. When the hammer 47 moves forward, it receives a rotational force from the hammer ball 48. That is, the hammer 47 moves forward while rotating. When the hammer 47 moves forward while rotating, the hammer protrusion 475 comes into contact with the anvil protrusion 102 while rotating. As a result, the anvil protrusion 102 is struck in the rotational direction by the hammer protrusion 475. 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.

[0102] [Sealing and supporting members] The seal member 70 is disposed inside the hammer case 4. The seal member 70 is disposed radially inward of the third cylindrical portion 404 of the hammer case 4. The seal member 70 is disposed between the anvil bearing 46 and the anvil shaft portion 101 inside the hammer case 4. At least a portion of the seal member 70 contacts the outer peripheral surface of the anvil shaft portion 101. The seal member 70 is supported by the anvil bearing 46. The seal member 70 is held in place by the anvil bearing 46. The seal member 70 is disposed radially inward of the front convex portion 465 of the anvil bearing 46. In this embodiment, the seal member 70 is a lip seal.

[0103] The seal member 70 seals the boundary between the anvil bearing 46 and the anvil shaft portion 101. The seal member 70 prevents lubricant (grease) present inside the hammer case 4 from leaking out of the hammer case 4 through the opening at the front end of the hammer case 4. The seal member 70 also prevents foreign matter from outside the hammer case 4 from entering the inside of the hammer case 4.

[0104] As shown in FIG. 5 , the seal member 70 has an outer annular portion 71, a rear lip portion 72, and a front lip portion 73. The outer peripheral surface of the outer annular portion 71, which faces radially outward, contacts the inner peripheral surface 465S of the front convex portion 465. The rear surface of the outer annular portion 71, which faces rearward, contacts the front surface 463F of the front support portion 463. The rear lip portion 72 and the front lip portion 73 are each positioned radially inward from the outer annular portion 71. The rear lip portion 72 is positioned rearward from the front lip portion 73. The rear lip portion 72 and the front lip portion 73 each contact the outer peripheral surface of the anvil shaft portion 101. The rear lip portion 72 and the front lip portion 73 each contact the outer peripheral surface of the front cylindrical portion 114.

[0105] The support member 80 is disposed inside the hammer case 4. The support member 80 is disposed forward of the seal member 70. The support member 80 faces the seal member 70. The support member 80 is capable of supporting the seal member 70 from the front. As described above, an opening in which the anvil shaft portion 101 is disposed is provided at the front end of the hammer case 4. The opening of the hammer case 4 is defined by the inner circumferential surface 405S of the fourth cylindrical portion 405. The support member 80 is disposed so as to face the opening of the hammer case 4. The support member 80 prevents the seal member 70 from slipping forward through the opening of the hammer case 4.

[0106] The support member 80 is ring-shaped. The support member 80 is a washer that is disposed around the anvil shaft portion 101. The support member 80 is spaced apart from the anvil shaft portion 101.

[0107] The support member 80 is fixed to at least one of the hammer case 4 and the anvil bearing 46. In this embodiment, the support member 80 is sandwiched in the front-to-rear direction between the anvil bearing 46 and a part of the hammer case 4. In this embodiment, the outer edge portion of the support member 80 on the radially outer side is sandwiched between the front surface 465F of the front convex portion 465 and the rear surface 405R of the fourth cylindrical portion 405.

[0108] The support member 80 is inserted into the hammer case 4 from an opening provided at the rear end of the hammer case 4. After the support member 80 is inserted into the hammer case 4 so that the front surface of the support member 80 contacts the rear surface 405R of the fourth cylindrical portion 405, the seal member 70 and the anvil bearing 46 are each inserted into the hammer case 4 from openings provided at the rear end of the hammer case 4. The anvil bearing 46 is fixed to the hammer case 4 by being press-fitted into the second cylindrical portion 402. The front surface 461F of the outer ring portion 461 contacts the rear surface 404R of the third cylindrical portion 404, thereby positioning the hammer case 4 and the anvil bearing 46 in the front-to-rear direction.

[0109] The support member 80 may be disposed on a portion of the periphery of the anvil shaft portion 101. A cutout may be provided in a portion of the support member 80. The support member 80 may be a circlip. When the support member 80 is a circlip, it may be disposed inside the hammer case 4 via an opening provided in the front end portion of the hammer case 4.

[0110] [Anvil] Fig. 7 is a perspective view of the anvil 10 according to the embodiment, seen from the front right. Fig. 8 is a side view of the anvil 10 according to the embodiment. Fig. 9 is a view of the anvil 10 according to the embodiment, seen from the front. Fig. 10 is an enlarged view of a portion of the anvil 10 according to the embodiment.

[0111] The anvil 10 has an anvil shaft portion 101 extending in the axial direction, and anvil protrusion portions 102 protruding radially outward from the anvil shaft portion 101. Two anvil protrusion portions 102 are provided.

[0112] The anvil shaft portion 101 has a first shaft portion 110, a second shaft portion 120, a transition portion 130, and a tip portion 140. The rear end of the first shaft portion 110 is connected to the anvil protrusion portion 102. The second shaft portion 120 is disposed forward of the first shaft portion 110. The transition portion 130 is disposed between the first shaft portion 110 and the second shaft portion 120 in the front-to-rear direction. The front end of the first shaft portion 110 is connected to the rear end of the transition portion 130. The rear end of the second shaft portion 120 is connected to the front end of the transition portion 130. The first shaft portion 110 and the second shaft portion 120 are connected via the transition portion 130. The tip portion 140 is disposed forward of the second shaft portion 120.

[0113] The first shaft portion 110 is disposed inside the hammer case 4. At least a portion of the first shaft portion 110 is supported by the anvil bearing 46. The cross section of the first shaft portion 110 perpendicular to the rotation axis AX has a circular outer shape. The first shaft portion 110 has a recess 111, a rear cylindrical portion 112, a recess 113, and a front cylindrical portion 114. The recess 111 is disposed rearward of the rear cylindrical portion 112. The recess 111 is provided at the boundary between the anvil shaft portion 101 and the anvil protrusion 102. The outer diameter of the recess 111 is smaller than the outer diameter of the rear cylindrical portion 112. As shown in FIG. 5 , the rear cylindrical portion 112 is supported by a rear support portion 462 of the anvil bearing 46. The outer peripheral surface of the rear cylindrical portion 112 and the inner peripheral surface 462S of the rear support portion 462 are in contact with each other. The recess 113 is disposed forward of the rear cylindrical portion 112. The outer diameter of the recess 113 is smaller than the outer diameter of the rear cylindrical portion 112. The front cylindrical portion 114 is disposed forward of the recess 113. The outer diameter of the front cylindrical portion 114 is substantially equal to the outer diameter of the rear cylindrical portion 112. As shown in FIG. 5 , the front cylindrical portion 114 is supported by the front support portion 463 of the anvil bearing 46. The outer peripheral surface of the front cylindrical portion 114 and the inner peripheral surface 463S of the front support portion 463 are in contact with each other.

[0114] The second shaft portion 120 is disposed outside the hammer case 4. The second shaft portion 120 protrudes forward from an opening provided at the front end of the hammer case 4. A socket 300 is attached to the second shaft portion 120. The outer shape of a cross section of the second shaft portion 120 perpendicular to the rotation axis AX is substantially rectangular. The second shaft portion 120 has four flat portions 121 and four corners 122. As shown in FIG. 9 , the flat portion 121 includes a flat portion 121A, a flat portion 121B adjacent to the flat portion 121A in the circumferential direction, a flat portion 121C adjacent to the flat portion 121B in the circumferential direction, and a flat portion 121D adjacent to the flat portion 121C in the circumferential direction. Corner portion 122 includes corner portion 122A provided at the boundary between planar portion 121A and planar portion 121B, corner portion 122B provided at the boundary between planar portion 121B and planar portion 121C, corner portion 122C provided at the boundary between planar portion 121C and planar portion 121D, and corner portion 122D provided at the boundary between planar portion 121D and planar portion 121A.

[0115] 10, one flat surface portion 121 has a first edge 124 extending in the front-rear direction and a second edge 125 extending in the front-rear direction. The first edge 124 is disposed at an end portion on one circumferential side of the flat surface portion 121. The second edge 125 is disposed at an end portion on the other circumferential side of the flat surface portion 121. Each of the four flat surface portions 121 has the first edge 124 and the second edge 125.

[0116] 9, when the counterclockwise direction as viewed from the front of the anvil 10 is defined as the forward rotation direction, the first edge 124 is positioned closer to the forward rotation side than the second edge 125. When tightening a bolt inserted into the socket 300, the anvil 10 is rotated to one side in the circumferential direction. That is, during the bolt tightening operation, the anvil 10 is rotated in the forward rotation direction.

[0117] The transition portion 130 connects the cylindrical first shaft portion 110 and the rectangular prism-shaped second shaft portion 120. At least a portion of the transition portion 130 smoothly connects the outer circumferential surface of the front cylindrical portion 114 of the first shaft portion 110 and the outer surface of the second shaft portion 120. The transition portion 130 has a support portion 131 connected to the first edge 124 of the second shaft portion 120 and a connection portion 135 connected to the second edge 125 of the second shaft portion 120. In the circumferential direction, the position of the support portion 131 and the position of the first edge 124 are substantially equal. In the circumferential direction, the position of the connection portion 135 and the position of the second edge 125 are substantially equal. That is, the support portion 131 is disposed immediately behind the first edge 124 (on an extension extending rearward from the first edge 124). The connecting portion 135 is disposed immediately behind the second edge 125 (on an extension extending rearward from the second edge 125). In the front-to-rear direction, the connecting portion 135 is disposed rearward of the support portion 131. The transition portion 130 connects to the second edge 125 rearward of the support portion 131.

[0118] The transition portions 130 are connected to the four first edges 124, respectively. The transition portions 130 are connected to the four second edges 125, respectively. Four support portions 131 are provided at intervals in the circumferential direction. Four connection portions 135 are provided at intervals in the circumferential direction. As shown in FIG. 9 , the support portions 131 include a support portion 131A connected to the first edge 124 of the planar portion 121A, a support portion 131B connected to the first edge 124 of the planar portion 121B, a support portion 131C connected to the first edge 124 of the planar portion 121C, and a support portion 131D connected to the first edge 124 of the planar portion 121D.

[0119] The rear end of the socket 300 attached to the second shaft portion 120 contacts each of the four support portions 131. The rear end of the socket 300 attached to the second shaft portion 120 does not contact each of the four connection portions 135.

[0120] The transition portion 130 has a tapered portion 134 connected to the front cylindrical portion 114. The rear end of the tapered portion 134 is connected to the front end of the front cylindrical portion 114. The outer diameter of the tapered portion 134 gradually decreases toward the front. The front end of the tapered portion 134 is connected to the flat portion 121 and the corner portion 122. A portion of the tapered portion 134 is cut away to form the support portion 131 and the connecting portion 135. The surface of the cut-away portion of the tapered portion 134 is curved. The transition portion 130 has a curved portion 132 connected to the flat portion 121. The curved portion 132 is provided between the connecting portion 135 and the support portion 131 in the circumferential direction. A curved portion 133 is formed at the boundary between the outer surface of the tapered portion 134 and the surface of the curved portion 132. The curved portion 133 is formed to connect the connecting portion 135 and the support portion 131. The curved portion 133 is inclined forward toward one circumferential side (the forward rotation direction side).

[0121] In the embodiment, a recess 123 is provided in a part of the flat surface portion 121. The recess 123 is formed so as to be recessed radially inward from the flat surface portion 121. The recess 123 is provided in a band shape so as to be inclined forward toward one circumferential side (the forward rotation direction side). The recess 123 may be absent.

[0122] [Impact tool operation] Next, the operation of the impact tool 1 will be described. For example, when performing a bolt tightening operation on a work object, the worker holds the grip portion 22 with, for example, the right hand and pulls the trigger lever 14 with the index finger of the right hand. When the trigger lever 14 is pulled, power is supplied from the battery pack 25 to the motor 6, the motor 6 starts, and the light 17 turns on. When the motor 6 starts, the rotor shaft 33 rotates. When the rotor shaft 33 rotates, the rotational force of the rotor shaft 33 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 own axis while meshing with the internal teeth of the internal gear 43. The planetary gear 42 is rotatably supported on the spindle 8 via the pin 42P. The revolution of the planetary gear 42 rotates the spindle 8 at a rotational speed lower than that of the rotor shaft 33.

[0123] When the spindle 8 rotates while the hammer protrusion 475 and the anvil protrusion 102 are in contact with each other, the anvil 10 rotates together with the hammer 47 and the spindle 8. As the anvil 10 rotates, the bolt tightening operation progresses.

[0124] As the bolt tightening operation progresses, if a load equal to or greater than a predetermined value acts on the anvil 10, the rotation of the anvil 10 and the hammer 47 stops. If the spindle 8 rotates while the rotation of the hammer 47 is stopped, the hammer 47 moves rearward. As the hammer 47 moves rearward, the contact between the hammer protrusion 475 and the anvil protrusion 102 is released.

[0125] When the hammer 47 moves rearward, the hammer 47 rotates relative to the spindle shaft portion 801. The washer 61 is spaced apart from the hammer 47 and the spindle 8. Therefore, the rotation of the hammer 47 is not hindered by the washer 61. In addition, the support ball 54 is disposed between the washer 61 and the hammer 47. The rotation of the support ball 54 allows the hammer 47 to rotate smoothly.

[0126] The hammer 47, which has moved rearward, moves forward while rotating due to the elastic force of the first coil spring 51 and the second coil spring 52. As the hammer 47 moves forward while rotating, the anvil protrusion 102 is struck in the rotational direction by the hammer protrusion 475. This causes the anvil 10 to rotate about the rotation axis AX with high torque. As a result, the screw is tightened into the workpiece with high torque.

[0127] [Impact wrench manufacturing method] In the above configuration, even if the outer diameter of the anvil shaft portion 101 is changed, the seal member 70 is prevented from coming off the hammer case 4 simply by providing a support member 80 in accordance with the change in the outer diameter of the anvil shaft portion 101. In the following description, the above-mentioned impact tool 1 will be referred to as the first impact wrench 1 as appropriate, and an impact tool having an anvil shaft portion 101B with an outer diameter different from the outer diameter of the anvil shaft portion 101 of the first impact wrench 1 will be referred to as the second impact wrench 1B as appropriate.

[0128] As described above, the first impact wrench 1 has an anvil shaft portion 101 (first anvil shaft portion), a hammer case 4 (first hammer case), an anvil bearing 46 (first anvil bearing) provided between the anvil shaft portion 101 and the hammer case 4, and a sealing member 70 (first sealing member) prevented from coming off by a support member 80 separate from the hammer case 4.

[0129] 11 is an enlarged longitudinal cross-sectional view of a portion of a second impact wrench 1B according to an embodiment. In the example shown in FIG. 11, the second impact wrench 1B includes an anvil shaft 101B (second anvil shaft) having an outer diameter larger than that of the anvil shaft 101 (first anvil shaft), a hammer case 4 having the same shape and dimensions as the hammer case 4 of the first impact wrench 1, an anvil bearing 46B (second anvil bearing) provided between the anvil shaft 101B and the hammer case 4, and a seal member 70B (second seal member) prevented from coming off by the hammer case 4. In the second impact wrench 1B, since the outer diameter of the anvil shaft 101B is larger, the seal member 70B is disposed radially outward of the seal member 70 of the first impact wrench 1. Because the seal member 70B is disposed radially outward, in manufacturing the second impact wrench 1B, the seal member 70B is prevented from coming off by the fourth cylindrical portion 405 at the front end of the hammer case 4, without providing the support member 80 and without changing the size of the opening of the hammer case 4. When it is required to use an anvil shaft portion 101 with a small outer diameter, as in the first impact wrench 1, by using the support member 80, the seal member 70 is prevented from coming off by the support member 80, without changing the size of the opening of the hammer case 4. In this way, when it is required to use anvil shaft portions (101, 101B) with different outer diameters in manufacturing the impact wrench (1, 1B), it is possible to manufacture multiple types of impact wrenches (1, 1B) that can prevent the seal member (70, 70B) from coming off while using hammer cases 4 of the same shape and dimensions, depending on whether or not the support member 80 is used. Impact wrench manufacturers can manufacture multiple types of impact wrenches (1, 1B) that have anvil shaft portions (101, 101B) with different outer diameters and that can prevent the sealing members (70, 70B) from coming off, simply by using the support member 80, without having to prepare multiple types of hammer cases 4. The first impact wrench 1 and the second impact wrench 1B are manufactured by the same impact wrench manufacturer.

[0130] [effect] As described above, in the embodiment, the impact tool 1 includes the motor 6 having the rotor 27 that rotates around the rotation axis AX extending in the front-rear direction, the spindle 8 that rotates by the rotational force of the rotor 27, the anvil 10 that is disposed forward of at least a part of the spindle 8 and has the anvil shaft portion 101 that extends in the axial direction parallel to the rotation axis AX and the anvil protrusion portion 102 that protrudes from the anvil shaft portion 101 radially outward from the rotation axis AX, and the hammer 101 that is supported by the spindle 8 and has the hammer protrusion portion 475 that strikes the anvil protrusion portion 102 in the rotational direction. the anvil 10 and the hammer 47, a hammer case 4 that houses at least a portion of the anvil 10 and the hammer 47 and has an opening in which the anvil shaft portion 101 is disposed, an anvil bearing 46 that is fixed to the hammer case 4 inside the hammer case 4 and supports the anvil shaft portion 101, a seal member 70 that is disposed inside the hammer case 4 at the boundary between the anvil bearing 46 and the anvil shaft portion 101, and a support member 80 that is disposed inside the hammer case 4 so as to face the opening of the hammer case 4 and can support the seal member 70 from the front. The inner diameter of the support member 80 is smaller than the inner diameter of the opening of the hammer case 4.

[0131] In the above configuration, the seal member 70 prevents the lubricant present inside the hammer case 4 from leaking out of the hammer case 4 through the opening of the hammer case 4. The seal member 70 also prevents foreign matter outside the hammer case 4 from entering the inside of the hammer case 4 through the opening of the hammer case 4. The support member 80 prevents the seal member 70 from coming off the opening of the hammer case 4. Furthermore, because the inner diameter of the support member 80 is smaller than the inner diameter of the hammer case 4, the support member 80 prevents the leakage of lubricant and the intrusion of foreign matter. Furthermore, even if the size of the opening of the hammer case 4 is changed, for example, simply by changing the support member 80 in accordance with the change in the size of the opening of the hammer case 4, the seal member 70 is prevented from coming off, and the leakage of lubricant and the intrusion of foreign matter are prevented.

[0132] In the embodiment, the support member 80 faces the seal member 70 .

[0133] In the above configuration, the support member 80 can prevent the seal member 70 from coming out of the opening of the hammer case 4.

[0134] In an embodiment, support member 80 is disposed at least partially around anvil shaft portion 101 .

[0135] In the above configuration, the support member 80 can stably support the seal member 70.

[0136] In an embodiment, support member 80 includes a washer disposed around anvil shaft portion 101 .

[0137] In the above configuration, the washer can come into contact with the seal member 70 with a uniform force, so that the application of a large force locally to the seal member 70 is suppressed.

[0138] In an embodiment, at least a portion of the seal member 70 contacts the anvil shaft portion 101. The support member 80 is spaced from the anvil shaft portion 101.

[0139] In the above configuration, the support member 80 is spaced apart from the anvil shaft portion 101, allowing the anvil 10 to rotate smoothly.

[0140] In an embodiment, the support member 80 is fixed to at least one of the hammer case 4 and the anvil bearing 46 .

[0141] In the above configuration, changes in the relative positions of the support member 80, the hammer case 4, and the anvil bearing 46 are suppressed.

[0142] In this embodiment, the support member 80 is sandwiched between the anvil bearing 46 and a part of the hammer case 4 in the front-rear direction.

[0143] The above configuration suppresses changes in the relative positions of the support member 80, the hammer case 4, and the anvil bearing 46. In addition, the impact tool 1 is easy to assemble.

[0144] In an embodiment, the seal member 70 is supported on the anvil bearing 46 .

[0145] In the above configuration, changes in the relative positions of the support member 80 and the anvil bearing 46 are suppressed.

[0146] [Other embodiments] FIG. 12 is an enlarged longitudinal cross-sectional view of a portion of an impact tool 1C according to another embodiment. In the above-described embodiment, the support member 80 is arranged inside the hammer case 4 so as to face the opening of the hammer case 4. As shown in FIG. 12, at least a portion of the support member 80C may be arranged outside the hammer case 4 so as to face the opening of the hammer case 4. The rear portion of the support member 80C is sandwiched between the anvil bearing 46 and the fourth cylindrical portion 405 and fixed to the hammer case 4. A portion of the support member 80 is bent, and the front portion of the support member 80 is arranged forward of the opening of the hammer case 4. In the example shown in FIG. 12 as well, the support member 80C can support the seal member 70 from the front and prevent the seal member 70 from coming off.

[0147] In the above embodiment, the anvil bearing 46 is an iron sleeve. The anvil bearing 46 may be a needle bearing or a ball bearing.

[0148] In the above-described embodiment, the impact tool 1 is an impact wrench. The impact tool 1 may be an impact driver.

[0149] In the above-described embodiment, the power source for the impact tool 1 does not have to be the battery pack 25, and may be a commercial power source (AC power source). [Explanation of symbols]

[0150] 1...impact tool, 2...housing, 2L...left housing, 2R...right housing, 2S...screw, 2T...screw, 3...cover, 4...hammer case, 6...motor, 7...reduction mechanism, 8...spindle, 9...impact mechanism, 10...anvil, 12...fan, 13...battery mounting section, 14...trigger lever, 15...forward / reverse switching lever, 16...operation display section, 16A...operation button, 16B...indicator display, 17...light, 19...air intake, 20...air exhaust, 21...motor housing section, 22...grip section, 23...battery holding section, 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, 37... Sensor board, 38... Busbar unit, 39... Rotor bearing, 39F... Front rotor bearing, 39R... Rear rotor bearing, 41... Pinion gear, 42... Planetary gear, 42P... Pin, 43... Internal gear, 44... Spindle bearing, 46... Anvil bearing, 47... Hammer, 48... Hammer ball, 50... Coil spring, 51... First Coil spring, 52...second coil spring, 53...washer, 54...support ball, 61...washer, 62...washer, 70...sealing member, 71...outer ring portion, 72...rear lip portion, 73...front lip portion, 80...supporting member, 101...anvil shaft portion, 102...anvil protrusion portion, 103...recess, 110...first shaft portion, 111...recess, 112...rear cylindrical portion, 113...recess, 114...front cylindrical portion, 120...second shaft portion, 121...flat portion, 121A...flat portion, 121B...flat portion, 121C...flat portion, 121D...flat portion, 122...corner portion, 122A...corner portion , 122B...corner portion, 122C...corner portion, 122D...corner portion, 123...recess, 124...first edge, 125...second edge, 130...transition portion, 131...support portion, 131A...support portion, 131B...support portion, 131C...support portion, 131D...support portion, 132...curved portion, 133...curved portion, 134...tapered portion, 135...connection portion, 140...tip portion, 241...recess, 242...recess, 300...socket, 401...first cylindrical portion, 402...second cylindrical portion, 402R...rear surface, 402S...inner surface, 403...case connection portion, 404...third cylindrical portion, 404R...rear surface, 404S...inner surface, 405...fourth cylindrical portion,405R...Rear surface, 405S...Inner surface, 461...Outer ring, 461F...Front, 461R...Rear, 461S...Inner surface, 461T...Outer surface, 462...Rear support, 462F...Front, 462S...Inner Peripheral surface, 463...Front support part, 463F...Front surface, 463R...Rear surface, 463S...Inner circumferential surface, 464...Rear convexity, 464R...Rear surface, 464T...Outer circumferential surface, 465...Front convexity, 465F...Front surface, 46 5S...inner peripheral surface, 465T...outer peripheral surface, 466...recessed portion, 471...base portion, 473...rear ring portion, 474...support ring portion, 474A...large diameter portion, 474B...small diameter portion, 474C...step portion, 475...hammer protrusion portion, 476...recessed portion, 477...hammer groove, 478...support groove, 801...spindle shaft portion, 802...flange portion, 803...convex portion, 804...spindle groove, AX...rotating axis.

Claims

1. a motor having a rotor; a striking mechanism rotated by the rotor; an anvil that is struck by the striking mechanism; a hammer case having an opening; an anvil bearing fixed to the hammer case inside the hammer case and supporting the anvil; a seal member disposed inside the hammer case between the anvil bearing and the anvil; a support member that is arranged to face the opening and that can support the seal member from the front, The inner diameter of the support member is smaller than the inner diameter of the opening. Impact tool.

2. The support member faces the seal member. The impact tool according to claim 1 .

3. the support member is disposed around at least a portion of the periphery of the anvil; The impact tool according to claim 1 .

4. The support member includes a washer disposed around the anvil. The impact tool according to claim 1 .

5. At least a portion of the seal member contacts the anvil; the support member is spaced from the anvil; The impact tool according to claim 1 .

6. The support member is fixed to at least one of the hammer case and the anvil bearing. The impact tool according to claim 1 .

7. The support member is sandwiched between the anvil bearing and a part of the hammer case in the front-rear direction. The impact tool according to claim 1 .

8. The seal member is supported by the anvil bearing. The impact tool according to claim 1 .

9. a motor having a rotor; a striking mechanism rotated by the rotor; an anvil that is struck by the striking mechanism; a hammer case that houses a portion of the anvil and the striking mechanism and has an opening in which the anvil is disposed; an anvil bearing fixed to the hammer case inside the hammer case and supporting the anvil; a seal member disposed between the anvil bearing and the anvil inside the hammer case and held in place by the anvil bearing; a support member having an inner diameter smaller than the inner diameter of the opening and supporting the seal member, Impact tool.

10. a first impact wrench having a first anvil shaft portion, a first hammer case, a first anvil bearing provided between the first anvil shaft portion and the first hammer case, and a first seal member prevented from coming off by a support member separate from the first hammer case; a second impact wrench having a second anvil shaft portion having an outer diameter larger than that of the first anvil shaft portion, the first hammer case, a second anvil bearing provided between the second anvil shaft portion and the first hammer case, and a second seal member prevented from coming off by the first hammer case; and the second impact wrench is manufactured by the same manufacturer as the impact wrench. How to manufacture an impact wrench.

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