Impact tools

Abstract

To suppress the enlargement of an impact tool while improving striking efficiency.SOLUTION: An impact tool is equipped with a motor, a spindle that has a spindle shaft portion and a flange portion provided at a rear part of the spindle shaft portion, and is rotated by the rotational force of the motor, an anvil that has an anvil shaft portion disposed ahead of the spindle and equipped with a tip end tool, and an anvil projecting portion projecting radially outward from the anvil shaft portion, a hammer that is supported by the spindle shaft portion and strikes the anvil projecting portion in a rotating direction, a first coil spring and a second coil spring disposed around the spindle shaft, a cup washer that is disposed in a recessed portion provided at a rear part of the hammer and supports a front end portion of the first coil spring and a front end portion of the second coil spring, and a supporting ball that is disposed in a supporting groove provided on the hammer inside the recessed portion and supports the cup washer.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The technology disclosed herein relates to impact tools. [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] In order to improve the workability when using an impact tool, a technique is required that prevents the impact tool from becoming larger while improving the impact efficiency.

[0005] The technology disclosed in this specification aims to prevent the impact tool from becoming larger while improving impact efficiency. [Means for solving the problem]

[0006] This specification discloses an impact tool. The impact tool may include: a spindle having a motor, a spindle shaft, and a flange provided at a rear portion of the spindle shaft and rotated by a torque of the motor; an anvil disposed forward of the spindle and having an anvil shaft to which a tool bit is attached and an anvil protrusion protruding radially outward from the anvil shaft; a hammer supported on the spindle shaft and having a hammer protrusion that strikes the anvil protrusion in the rotational direction; first and second coil springs disposed around the spindle shaft; cup washers disposed in recesses provided at the rear portion of the hammer and supporting front ends of the first and second coil springs; and a support ball disposed inside the recesses and in support grooves provided in the hammer and supporting the cup washers. [Effects of the Invention]

[0007] According to the technology disclosed in this specification, it is possible to prevent the impact tool from becoming larger while improving impact efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front perspective view showing an impact tool according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the impact tool according to the first embodiment, seen from behind. [Figure 3] FIG. 3 is a side view showing the impact tool according to the first embodiment. [Figure 4] FIG. 4 is a vertical cross-sectional view showing the impact tool according to the first embodiment. [Figure 5] FIG. 5 is a vertical cross-sectional view showing an upper portion of the impact tool according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing the upper part of the impact tool according to the first embodiment. [Figure 7] FIG. 7 is an exploded perspective view of a part of the impact tool according to the first embodiment, seen from the front. [Figure 8] FIG. 8 is an exploded perspective view showing a part of the impact tool according to the first embodiment, as seen from the rear. [Figure 9] FIG. 9 is a front perspective view showing the cup washer and the support ball according to the first embodiment. [Figure 10] FIG. 10 is a rear perspective view showing the cup washer and the support ball according to the first embodiment. [Figure 11] FIG. 11 is a front perspective view showing the hammer according to the first embodiment. [Figure 12] FIG. 12 is a front view of the hammer according to the first embodiment. [Figure 13] FIG. 13 is a rear perspective view showing the hammer according to the first embodiment. [Figure 14] FIG. 14 is a vertical cross-sectional view showing the hammer according to the first embodiment. [Figure 15] FIG. 15 is a vertical cross-sectional view showing an upper portion of an impact tool according to the second embodiment. [Figure 16] FIG. 16 is a cross-sectional view showing an upper portion of an impact tool according to the second embodiment. [Figure 17] FIG. 17 is an exploded perspective view of a part of the impact tool according to the second embodiment, seen from the front. [Figure 18] FIG. 18 is an exploded perspective view showing a part of the impact tool according to the second embodiment, as seen from the rear. [Figure 19] FIG. 19 is a front perspective view showing a washer and a support ball according to the second embodiment. [Figure 20] FIG. 20 is a rear perspective view showing the washer and the support ball according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] In one or more embodiments, the impact tool may include a motor, a spindle having a spindle shaft portion and a flange portion provided at the rear of the spindle shaft portion and rotated by the rotational force of the motor, an anvil arranged forward of the spindle and having an anvil shaft portion to which a tool bit is attached and an anvil protrusion protruding radially outward from the anvil shaft portion, a hammer supported on the spindle shaft portion and having a hammer protrusion that strikes the anvil protrusion in the rotational direction, a first coil spring and a second coil spring arranged around the spindle shaft portion, a cup washer arranged in a recess provided at the rear of the hammer and supporting a front end of the first coil spring and a front end of the second coil spring, and a support ball arranged in a support groove provided in the hammer inside the recess and supporting the cup washer.

[0010] In the above configuration, the front end of the first coil spring and the front end of the second coil spring are supported by the cup washer, thereby preventing the impact tool from becoming larger in size in the axial direction parallel to the rotational axis of the motor. Furthermore, because the cup washer is supported by the support ball, when the spindle shaft and the hammer rotate relative to each other, the rotation of the support ball allows the hammer to rotate smoothly. The smooth rotation of the hammer improves impact efficiency. Because the front end of the first coil spring and the front end of the second coil spring are supported by one cup washer, only one support groove is required, preventing the impact tool from becoming larger in size in the axial direction.

[0011] In one or more embodiments, the cup washer may be separate from the hammer and spindle.

[0012] In the above configuration, the rotation of the hammer is not hindered by the cup washer, so the hammer can rotate smoothly.

[0013] In one or more embodiments, the cup washer may have an inner ring portion that supports the front end of the second coil spring, an outer ring portion that is positioned radially outward and forward of the inner ring portion and supports the front end of the first coil spring, and a connecting ring portion that connects the outer edge of the inner ring portion and the inner edge of the outer ring portion.

[0014] In the above configuration, the first coil spring having a long overall length and the second coil spring having a short overall length can be supported by the cup washer while preventing the impact tool from becoming too large in the axial direction.

[0015] In one or more embodiments, the support ball may contact the front surface of the outer ring portion.

[0016] In the above-described configuration, the outer ring portion is supported by the support ball, allowing the hammer to rotate smoothly.

[0017] In one or more embodiments, the hammer has a base portion arranged around the spindle shaft portion, a front ring portion protruding forward from the outer periphery of the base portion, a rear ring portion protruding rearward from the outer periphery of the base portion, a support ring portion protruding rearward from the inner periphery of the base portion and supported on the spindle shaft portion via a hammer ball, and a hammer protrusion portion protruding radially inward from the inner periphery of the front ring portion and striking the anvil protrusion portion in the rotational direction, and the recess may be defined by the rear surface of the base portion, the inner periphery of the rear ring portion, and the outer periphery of the support ring portion.

[0018] With the above configuration, the impact tool is prevented from becoming large in size in the axial direction.

[0019] In one or more embodiments, the support groove may be provided on the rear surface of the base portion.

[0020] With the above configuration, the impact tool is prevented from becoming large in size in the axial direction.

[0021] In one or more embodiments, the support ball may be located forward of the rear end of the hammer ball.

[0022] With the above configuration, the impact tool is prevented from becoming large in size in the axial direction.

[0023] In one or more embodiments, the front ring portion is positioned radially outward from the anvil projection, and the position of the front ring portion and the position of at least a portion of the anvil projection may be the same in the axial direction.

[0024] In the above configuration, the moment of inertia of the hammer increases when the hammer protrusion strikes the anvil protrusion, thereby increasing the striking force.

[0025] In one or more embodiments, the impact tool may include a spindle having a motor, a spindle shaft portion, and a flange portion provided at the rear of the spindle shaft portion, and rotated by the rotational force of the motor; an anvil arranged forward of the spindle and having an anvil shaft portion to which a tool bit is attached and an anvil protrusion protruding radially outward from the anvil shaft portion; a hammer supported on the spindle shaft portion and having a hammer protrusion that strikes the anvil protrusion in the rotational direction; a first coil spring and a second coil spring arranged around the spindle shaft portion; a washer arranged opposite the front surface of the flange portion and supporting the rear end of the first coil spring and the rear end of the second coil spring; and a support ball arranged between the front surface of the flange portion and the rear surface of the washer and supporting the washer.

[0026] In the above configuration, the rear end of the first coil spring and the rear end of the second coil spring are supported by the washer, which prevents the impact tool from becoming too large in the axial direction parallel to the rotation axis of the motor. Furthermore, because the washer is supported by the support ball, when the spindle shaft and the hammer rotate relative to each other, the rotation of the support ball allows the hammer to rotate smoothly. The smooth rotation of the hammer improves impact efficiency.

[0027] In one or more embodiments, the washer may have a support groove in which the support ball is positioned.

[0028] In the above configuration, the rear end of the first coil spring and the rear end of the second coil spring are supported by one washer, so only one support groove is required, which prevents the impact tool from becoming too large in the axial direction.

[0029] In one or more embodiments, the washer may be separate from the flange portion.

[0030] In the above configuration, the rotation of the hammer is not hindered by the flange portion, so the hammer can rotate smoothly.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] [First embodiment] A first embodiment will be described. <Impact tool> Fig. 1 is a front perspective view of the impact tool 1 according to this embodiment. Fig. 2 is a rear perspective view of the impact tool 1 according to this embodiment. Fig. 3 is a side view of the impact tool 1 according to this embodiment. Fig. 4 is a vertical cross-sectional view of the impact tool 1 according to this embodiment.

[0035] In this embodiment, the impact tool 1 is an impact wrench and includes a housing 2, a hammer case 4, a motor 6, a reduction gear mechanism 7, a spindle 8, a striking mechanism 9, an anvil 10, a fan 12, a battery mounting section 13, a trigger lever 14, a forward / reverse rotation switch lever 15, an operation display section 16, a light 17, and a controller 18.

[0036] 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.

[0037] The housing 2 has a motor accommodating portion 21, a grip portion 22, and a battery holding portion 23.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The hammer case 4 houses at least a portion of the reduction mechanism 7, the spindle 8, the striking mechanism 9, and the anvil 10. At least a portion of the reduction mechanism 7 is disposed inside the bearing box 24. The reduction mechanism 7 includes a plurality of gears.

[0043] 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 connected to the front of the motor accommodating section 21. A bearing box 24 is fixed to the rear of the hammer case 4. A screw thread is formed on the outer periphery of the bearing box 24. A screw groove is formed on the inner periphery of the hammer case 4. The screw thread of the bearing box 24 and the screw groove of the hammer case 4 are coupled together, thereby fixing the bearing box 24 and the hammer case 4 together.

[0044] 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 supported by 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 about a rotation axis AX extending in the front-rear direction.

[0045] 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 driven by the rotor 27.

[0046] 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 forward of the reduction mechanism 7. The spindle 8 is disposed rearward of the anvil 10.

[0047] 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.

[0048] 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 tip tool, is attached to the front end of the anvil 10.

[0049] 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 housing 2 flows into the internal space of the housing 2 through the air intake port 19. The air that has flowed into the internal space of the housing 2 cools the motor 6 by circulating through the internal space of the housing 2. As the fan 12 rotates, the air that has circulated through the internal space of the housing 2 flows out into the external space of the housing 2 through the air exhaust port 20.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] The controller 18 outputs a control signal to control the motor 6. The controller 18 includes a substrate on which a plurality of electronic components are mounted. Examples of the electronic components mounted on the substrate include a processor such as a CPU (Central Processing Unit), a non-volatile memory such as a ROM (Read Only Memory) or storage, a volatile memory such as a RAM (Random Access Memory), a transistor, and a resistor. The controller 18 is housed in a battery holding unit 23.

[0056] Fig. 5 is a vertical cross-sectional view showing an upper part of the impact tool 1 according to this embodiment. Fig. 6 is a horizontal cross-sectional view showing an upper part of the impact tool 1 according to this embodiment. Fig. 7 is an exploded perspective view from the front showing a part of the impact tool 1 according to this embodiment. Fig. 8 is an exploded perspective view from the rear showing a part of the impact tool 1 according to this embodiment.

[0057] The hammer case 4 has a first cylindrical portion 401, a second cylindrical portion 402, and a case connecting portion 403. 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 to connect the front end of the first cylindrical portion 401 and the outer circumferential surface of the second cylindrical portion 402. The rear end of the second cylindrical portion 402 protrudes rearward from the case connecting portion 403.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] The rotor magnet 34 is fixed to the rotor core 32. The rotor magnet 34 is disposed inside the rotor core 32.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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 protrusion 803 is arranged to surround the spindle bearing 44.

[0072] 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 protrusion 242 that protrudes forward from the front surface of the bearing box 24. The spindle bearing 44 is disposed around the protrusion 242.

[0073] The striking mechanism 9 has a hammer 47, a hammer ball 48, a coil spring 50, and a cup washer 61. The striking mechanism 9 including the hammer 47, the hammer ball 48, the coil spring 50, and the cup 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.

[0074] 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.

[0075] 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.

[0076] Fig. 11 is a front perspective view of the hammer 47 according to this embodiment. Fig. 12 is a front view of the hammer 47 according to this embodiment. Fig. 13 is a rear perspective view of the hammer 47 according to this embodiment. Fig. 14 is a vertical cross-sectional view of the hammer according to this embodiment.

[0077] The hammer 47 has a base portion 471 , a front ring portion 472 , a rear ring portion 473 , a support ring portion 474 , and a hammer protrusion portion 475 .

[0078] 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.

[0079] The front ring portion 472 protrudes forward from the outer periphery of the base portion 471. The front ring portion 472 is cylindrical.

[0080] The rear ring portion 473 protrudes rearward from the outer periphery of the base portion 471. The rear ring portion 473 is cylindrical.

[0081] 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.

[0082] The rear end of the rear ring portion 473 is disposed forward of the rear end of the support ring portion 474. The inner diameter of the rear ring portion 473 is larger than the outer diameter of the flange portion 802.

[0083] The hammer protrusion 475 protrudes radially inward from the inner circumferential surface of the front ring portion 472. The hammer protrusion 475 protrudes forward from the front surface of the base portion 471. The front surface of the hammer protrusion 475 is disposed forward of the front surface of the base portion 471. The front surface of the front ring portion 472 and the front surface of the hammer protrusion 475 are disposed in the same plane. Two hammer protrusions 475 are disposed in the circumferential direction.

[0084] 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.

[0085] The base portion 471 has grooves 90 formed at the boundary with the hammer protrusion 475. The grooves 90 extend in the radial direction. The grooves 90 are formed on one circumferential side and the other circumferential side of the hammer protrusion 475.

[0086] 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 .

[0087] The coil springs 50 are arranged around the spindle shaft portion 801. In this embodiment, the coil springs 50 include a first coil spring 51 and a second coil spring 52 arranged in parallel to each other. The second coil spring 52 is arranged radially inward of the first coil spring 51. In this 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.

[0088] The rear ends of the first coil springs 51 and the second coil springs 52 are supported by the front surface of the flange portion 802. As shown in FIGS. 6 and 7, the front surface of the flange portion 802 includes a first annular surface 802A, a second annular surface 802B disposed radially inward from the first annular surface 802A, and a third annular surface 802C disposed radially inward from the second annular surface 802B. The third annular surface 802C is disposed forward from the second annular surface 802B. The second annular surface 802B is disposed forward from the first annular surface 802A. A step portion 802D is provided at the boundary between the first annular surface 802A and the second annular surface 802B. A step portion 802E is provided at the boundary between the second annular surface 802B and the third annular surface 802C. The rear end portions of the first coil springs 51 are supported by the first annular surface 802A. The rear end portions of the second coil springs 52 are supported by the second annular surface 802B. The rear end portions of the first coil springs 51 are positioned in the radial direction by the stepped portions 802D. The rear end portions of the second coil springs 52 are positioned in the radial direction by the stepped portions 802E.

[0089] Furthermore, a recess 805 is provided at the boundary between the inner periphery of the third annular surface 802C and the outer periphery of the spindle shaft portion 801. The recess 805 is formed so as to surround the rotation axis AX.

[0090] 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 cup 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 cup washer 61. The cup 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.

[0091] The cup washer 61 is disposed rearward of the base portion 471. The cup washer 61 supports the front ends of the first coil spring 51 and the second coil spring 52. In the radial direction, the cup washer 61 is disposed between the rear ring portion 473 and the support ring portion 474. The cup washer 61 is disposed inside the recess 476. The cup 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.

[0092] 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 on 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 cup washer 61.

[0093] Fig. 9 is a perspective view from the front showing the cup washer 61 and the support ball 54 according to this embodiment. Fig. 10 is a perspective view from the rear showing the cup washer 61 and the support ball 54 according to this embodiment.

[0094] The cup washer 61 has an inner ring portion 611 , an outer ring portion 612 , and a connecting ring portion 613 .

[0095] The inner ring portion 611 supports the front ends of the second coil springs 52. The front ends of the second coil springs 52 contact the rear surface of the inner ring portion 611. The inner ring portion 611 is disposed around the small diameter portion 474B. The front surface of the inner ring portion 611 is disposed so as to face the rear surface of the large diameter portion 474A.

[0096] The outer ring portion 612 supports the front ends of the first coil springs 51. The front ends of the first coil springs 51 contact the rear surface of the outer ring portion 612. The outer ring portion 612 is disposed radially outward from the inner ring portion 611 and in front of the inner ring portion 611. The outer ring portion 612 is disposed radially between the rear ring portion 473 and the large diameter portion 474A. The outer ring portion 612 is disposed so as to protrude radially outward from the large diameter portion 474A.

[0097] Connecting ring portion 613 is arranged to connect the outer edge of inner ring portion 611 and the inner edge of outer ring portion 612. Connecting ring portion 613 is arranged around large diameter portion 474A. The inner circumferential surface of connecting ring portion 613 faces the outer circumferential surface of large diameter portion 474A. The boundary between connecting ring portion 613 and outer ring portion 612 is bent to fit along step portion 474C.

[0098] A plurality of support balls 54 are arranged in the circumferential direction. The support balls 54 contact the front surface of the outer ring portion 612.

[0099] The cup washer 61 is sandwiched between the coil spring 50 and the support ball 54 in the front-rear direction. The cup washer 61 is spaced apart from the hammer 47 and the spindle 8.

[0100] The anvil 10 has an anvil shaft portion 101 and an anvil protrusion portion 102 .

[0101] The anvil shaft portion 101 is disposed forward of the spindle 8 and the hammer 47. A socket, which is a type of tip tool, is attached to the front end portion of the anvil shaft portion 101.

[0102] 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 end 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.

[0103] The front ring portion 472 is disposed radially outward of the anvil projection 102. In the axial direction, the position of the front ring portion 472 and the position of at least a portion of the anvil projection 102 are the same. The outer periphery of the anvil projection 102 and the inner periphery of the front ring portion 472 are spaced apart.

[0104] The front end 472F of the front ring portion 472 is disposed forward of the rear end 402R of the second cylindrical portion 402. That is, the front portion of the front ring portion 472 and the rear portion of the second cylindrical portion 402 overlap in the axial direction. This increases the inertial force when the hammer 47 rotates. Also, the axial length, which indicates the distance between the rear end of the housing 2 and the front end of the anvil 10 in the axial direction, is shortened.

[0105] 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 spaced apart.

[0106] 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 all coincident. The anvil 10 rotates around the rotation axis AX. The anvil bearing 46 is disposed around the anvil shaft portion 101. The anvil bearing 46 is disposed inside the second cylindrical portion 402 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 rotatably supports the front portion of the anvil shaft portion 101.

[0107] The hammer protrusion 475 can come into contact with the anvil protrusion 102. When the motor 6 is driven while the hammer 47 and the anvil protrusion 102 are in contact with each other, the anvil 10 rotates together with the hammer 47 and the spindle 8.

[0108] The anvil 10 is struck in the rotational direction by the hammer 47. For example, during bolt tightening, 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.

[0109] When the hammer 47 moves rearward, the hammer 47 rotates relative to the spindle shaft portion 801. The cup 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 cup washer 61. In addition, the support ball 54 is disposed between the cup washer 61 and the hammer 47. The rotation of the support ball 54 allows the hammer 47 to rotate smoothly.

[0110] 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.

[0111] <Operation of impact tool> 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 grips 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.

[0112] 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.

[0113] 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, contact between the hammer protrusion 475 and the anvil protrusion 102 is released.

[0114] When the hammer 47 moves rearward, the hammer 47 rotates relative to the spindle shaft portion 801. The cup 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 cup washer 61. In addition, the support ball 54 is disposed between the cup washer 61 and the hammer 47. The rotation of the support ball 54 allows the hammer 47 to rotate smoothly.

[0115] 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.

[0116] <Effects> As described above, in this embodiment, the impact tool 1 includes the motor 6, the spindle shaft portion 801, the spindle 8 having the flange portion 802 provided at the rear of the spindle shaft portion 801 and rotated by the rotational force of the motor 6, the anvil 10 having the anvil shaft portion 101 arranged forward of the spindle 8 and on which the tool bit is attached, and the anvil protrusion portion 102 protruding radially outward from the anvil shaft portion 101, and the anvil protrusion portion 102 supported by the spindle shaft portion 801. The hammer 47 may include a hammer 47 having a hammer protrusion 475 that strikes the portion 102 in the rotational direction, a first coil spring 51 and a second coil spring 52 that are arranged around the spindle shaft portion 801, a cup washer 61 that is arranged in a recess 476 provided in the rear of the hammer 47 and supports the front end portion of the first coil spring 51 and the front end portion of the second coil spring 52, and a support ball 54 that is arranged in a support groove 478 provided in the hammer 47 inside the recess 476 and supports the cup washer 61.

[0117] In the above configuration, the front end portions of the first coil spring 51 and the second coil spring 52 are supported by the cup washer 61, which prevents the impact tool 1 from becoming larger in size in the axial direction parallel to the rotation axis AX of the motor 6. Furthermore, because the cup washer 61 is supported by the support ball 54, when the spindle shaft portion 801 and the hammer 47 rotate relative to each other, the rotation of the support ball 54 allows the hammer 47 to rotate smoothly. Since the hammer 47 rotates smoothly, impact efficiency is improved. Because the front end portions of the first coil spring 51 and the second coil spring 52 are supported by one cup washer 61, only one support groove 478 is required, which prevents the impact tool 1 from becoming larger in size in the axial direction.

[0118] In this embodiment, the cup washer 61 may be separate from the hammer 47 and the spindle 8 .

[0119] In the above configuration, the rotation of the hammer 47 is not hindered by the cup washer 61, so the hammer 47 can rotate smoothly.

[0120] In this embodiment, the cup washer 61 may have an inner ring portion 611 that supports the front end of the second coil spring 52, an outer ring portion 612 that is positioned radially outward and forward of the inner ring portion 611 and supports the front end of the first coil spring 51, and a connecting ring portion 613 that connects the outer edge of the inner ring portion 611 and the inner edge of the outer ring portion 612.

[0121] In the above configuration, the first coil spring 51 having a long overall length and the second coil spring 52 having a short overall length can be supported by the cup washer 61 while preventing the impact tool 1 from becoming too large in the axial direction.

[0122] In this embodiment, the support ball 54 may contact the front surface of the outer ring portion 612 .

[0123] In the above configuration, the outer ring portion 612 is supported by the support ball 54, allowing the hammer 47 to rotate smoothly.

[0124] In this embodiment, the hammer 47 has a base portion 471 arranged around the spindle shaft portion 801, a front ring portion 472 protruding forward from the outer periphery of the base portion 471, a rear ring portion 473 protruding rearward from the outer periphery of the base portion 471, a support ring portion 474 protruding rearward from the inner periphery of the base portion 471 and supported by the spindle shaft portion 801 via the hammer ball 48, and a hammer protrusion portion 475 protruding radially inward from the inner periphery of the front ring portion 472 and striking the anvil protrusion portion 102 in the rotational direction, and the recess 476 may be defined by the rear surface of the base portion 471, the inner periphery of the rear ring portion 473, and the outer periphery of the support ring portion 474.

[0125] In the above configuration, the impact tool 1 is prevented from becoming large in size in the axial direction.

[0126] In this embodiment, the support groove 478 may be provided on the rear surface of the base portion 471.

[0127] In the above configuration, the impact tool 1 is prevented from becoming large in size in the axial direction.

[0128] In this embodiment, the support ball 54 may be disposed forward of the rear end of the hammer ball 48 .

[0129] In the above configuration, the impact tool 1 is prevented from becoming large in size in the axial direction.

[0130] In this embodiment, the front ring portion is disposed radially outward of the anvil projection 102, and the position of the front ring portion and the position of at least a portion of the anvil projection 102 may be the same in the axial direction.

[0131] In the above configuration, the moment of inertia of the hammer 47 increases when the hammer protrusion 475 strikes the anvil protrusion 102, thereby increasing the striking force.

[0132] <Modification> In this embodiment, the front ends of the first coil spring 51 and the second coil spring 52 are supported by cup washers 61. The member supporting the front ends of the first coil spring 51 and the second coil spring 52 does not have to be the cup washer 61, and may be a member having a shape different from that of the cup washer 61.

[0133] [Second embodiment] A second embodiment will be described below. Components that are the same as or equivalent to those in the above-described embodiment will be given the same reference numerals, and descriptions of those components will be simplified or omitted.

[0134] Fig. 15 is a vertical cross-sectional view showing the upper part of the impact tool 1 according to this embodiment. Fig. 16 is a horizontal cross-sectional view showing the upper part of the impact tool 1 according to this embodiment. Fig. 17 is an exploded perspective view from the front showing a part of the impact tool 1 according to this embodiment. Fig. 18 is an exploded perspective view from the rear showing a part of the impact tool 1 according to this embodiment. Fig. 19 is a perspective view from the front showing the washer 62 and the support ball 55 according to this embodiment. Fig. 20 is a perspective view from the rear showing the washer 62 and the support ball 55 according to this embodiment.

[0135] Similar to the above-described embodiment, the first coil spring 51 and the second coil spring 52 are arranged around the spindle shaft portion 801. The front end portions of the first coil spring 51 and the second coil spring 52 are arranged inside the recessed portion 476. In this embodiment, there is no cup washer 61. The front end portions of the first coil spring 51 and the second coil spring 52 are fixed to the hammer 47 inside the recessed portion 476. The front end portions of the first coil spring 51 and the second coil spring 52 are fixed to the hammer 47 so as not to rotate relative to each other.

[0136] In this embodiment, a washer 62 is disposed at a position facing the front surface of the flange portion 802. The washer 62 supports the rear end portions of the first coil spring 51 and the second coil spring 52. A support ball 55 is disposed between the front surface of the flange portion 802 and the rear surface of the washer 62. The support ball 55 supports the washer 62.

[0137] The washer 62 has a ring-shaped base portion 621, an inner ring portion 622 that protrudes radially inward from the rear end of the inner circumferential surface of the base portion 621, and a front ring portion 623 that protrudes forward from the inner circumferential portion of the front surface of the base portion 621. A support groove 628 in which a support ball 55 is disposed is provided on the rear surface of the base portion 621. The support groove 628 is ring-shaped. A support groove 806 in which the support ball 55 is disposed is provided on the front surface of the flange portion 802. The support groove 806 is ring-shaped. A plurality of support balls 55 are disposed between the support groove 628 and the support groove 806. The support balls 55 keep the washer 62 apart from the flange portion 802.

[0138] The rear ends of the first coil springs 51 are supported by the front surface of the base portion 621. The rear ends of the first coil springs 51 are positioned in the radial direction by the front ring portion 623. The rear ends of the second coil springs 52 are supported by the front surface of the inner ring portion 622. The rear ends of the second coil springs 52 are positioned in the radial direction by the inner circumferential surface of the base portion 621.

[0139] For example, during bolt tightening work, if the load acting on the anvil 10 increases, the rotation of the anvil 10 and the hammer 47 stops. 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, respectively.

[0140] When the hammer 47 moves rearward, the hammer 47 rotates relative to the spindle shaft portion 801. The first coil spring 51 and the second coil spring 52 rotate together with the hammer 47. The washer 62 is spaced apart from the flange portion 802 of the spindle 8. Therefore, the rotation of the hammer 47 is not hindered by the flange portion 802. In addition, the support ball 55 is disposed between the washer 62 and the flange portion 802. The rotation of the support ball 55 allows the hammer 47 to rotate smoothly.

[0141] As described above, in this embodiment, the impact tool 1 may include: a spindle 8 having a motor 6, a spindle shaft portion 801, and a flange portion 802 provided at the rear of the spindle shaft portion 801, and rotating by the rotational force of the motor 6; an anvil 10 arranged forward of the spindle 8, the anvil shaft portion 101 to which a tool bit is attached, and the anvil protrusion portion 102 protruding radially outward from the anvil shaft portion 101; a hammer 47 supported by the spindle shaft portion 801 and having a hammer protrusion portion 475 that strikes the anvil protrusion portion 102 in the rotational direction; a first coil spring 51 and a second coil spring 52 arranged around the spindle shaft portion 801; a washer 62 arranged opposite the front surface of the flange portion 802, and supporting the rear end portion of the first coil spring 51 and the rear end portion of the second coil spring 52; and a support ball 55 arranged between the front surface of the flange portion 802 and the rear surface of the washer 62, and supporting the washer 62.

[0142] In the above configuration, the rear end portions of the first coil spring 51 and the second coil spring 52 are supported by the washer 62, which prevents the impact tool 1 from becoming larger in size in the axial direction parallel to the rotation axis AX of the motor 6. Furthermore, since the washer 62 is supported by the support ball 54, when the spindle shaft portion 801 and the hammer 47 rotate relative to each other, the hammer 47 can be rotated smoothly due to the rotation of the support ball 54. Since the hammer 47 is rotated smoothly, impact efficiency is improved.

[0143] In this embodiment, the washer 62 may have a support groove 628 in which the support ball 54 is positioned.

[0144] In the above configuration, one washer 62 supports the rear end of the first coil spring 51 and the rear end of the second coil spring 52, so only one support groove 628 is required, thereby preventing the impact tool 1 from becoming larger in the axial direction.

[0145] In this embodiment, the washer 62 may be separate from the flange portion 802 .

[0146] In the above configuration, the rotation of the hammer 47 is not hindered by the flange portion 802, so the hammer 47 can rotate smoothly.

[0147] [Other embodiments] In the above-described embodiment, the impact tool 1 is an impact wrench. The impact tool 1 may be an impact driver.

[0148] 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]

[0149] 1...Impact tool, 2...Housing, 2L...Left housing, 2R...Right housing, 2S...Screw, 2T...Screw, 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, 18...Controller, 19...Air intake, 20...Exhaust port, 21...Motor housing section, 22...Grip section, 23...Battery holding section, 24...Bearing box 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, 55...Support ball, 61...Cup washer, 62...Washer, 90...Groove, 101...Anvil shaft portion, 102...Anvil protrusion portion, 241...Concave portion, 242...Convex portion, 401...First cylindrical portion, 402...Second cylindrical portion, 402R...Rear end portion, 403...Case connection portion, 471...Base portion, 472...Front ring portion, 472F...Front end portion, 473...Rear ring portion, 474...Support ring portion, 474A...Large diameter portion, 47 4B...small diameter portion, 474C...step portion, 475...hammer protrusion portion, 476...recess portion, 477...hammer groove, 478...support groove, 611...inner ring portion, 612...outer ring portion, 613...connecting ring portion, 621...base portion, 622...inner ring portion, 623...front ring portion, 628...support groove, 801...spindle shaft portion, 802...flange portion, 802A...first annular surface, 802B...second annular surface, 802C...third annular surface, 802D...step portion, 802E...step portion, 803...convex portion, 804...spindle groove, 805...recess portion, 806...support groove, AX...rotating axis.

Claims

1. A motor; a spindle having a spindle shaft portion and a flange portion provided at a rear portion of the spindle shaft portion, the spindle being rotated by a rotational force of the motor; an anvil disposed forward of the spindle and including an anvil shaft portion to which a tool bit is attached and an anvil protrusion portion protruding radially outward from the anvil shaft portion; a hammer supported on the spindle shaft portion and having a hammer protrusion that strikes the anvil protrusion in a rotational direction; a first coil spring and a second coil spring disposed around the spindle shaft portion; a cup washer disposed in a recess provided in a rear portion of the hammer and supporting a front end portion of the first coil spring and a front end portion of the second coil spring; a support ball disposed in a support groove provided in the hammer inside the recess and supporting the cup washer; the cup washer includes an inner ring portion that supports a front end of the second coil spring, an outer ring portion that is disposed radially outward and forward of the inner ring portion and that supports a front end of the first coil spring, and a connecting ring portion that connects an outer edge portion of the inner ring portion and an inner edge portion of the outer ring portion, The support ball contacts the front surface of the outer ring portion. Impact tool.

2. the cup washer is spaced apart from each of the hammer and the spindle; The impact tool according to claim 1 .

3. The support ball contacts the front surface of the outer ring portion. The impact tool according to claim 1 .

4. the hammer has a base portion disposed around the spindle shaft portion, a front ring portion protruding forward from the outer periphery of the base portion, a rear ring portion protruding rearward from the outer periphery of the base portion, a support ring portion protruding rearward from the inner periphery of the base portion and supported by the spindle shaft portion via a hammer ball, and a hammer protrusion portion protruding radially inward from the inner periphery of the front ring portion and striking the anvil protrusion portion in the rotational direction, the recess is defined by a rear surface of the base portion, an inner peripheral surface of the rear ring portion, and an outer peripheral surface of the support ring portion. The impact tool according to claim 1 .

5. The support groove is provided on the rear surface of the base portion.

5. The impact tool according to claim 4.

6. The support ball is disposed forward of the rear end of the hammer ball.

6. The impact tool according to claim 5.

7. the front ring portion is disposed radially outward of the anvil protrusion, In the axial direction, the position of the front ring portion and the position of at least a part of the anvil protrusion are the same.

5. The impact tool according to claim 4.

Images