Impact tool

Abstract

To suppress life of an impact tool from shortening.SOLUTION: An impact tool comprises: a motor; a spindle at least a part of which is arranged in front of the motor and which is rotated by the motor; a hammer which is arranged around the spindle; an anvil at least a part of which is arranged in front of the spindle and which is impacted by the hammer in a rotation direction; and an internal space which is formed in the spindle to extend from an aperture arranged at a rear end face of the spindle to the front side. The internal space includes: a first space with a first inner diameter connected to the aperture; a second space arranged in front of the first space with a second inner diameter smaller than the first inner diameter; and a third space connected to a front end part of the second space with a third inner diameter larger than the second inner diameter. Lubrication oil is accommodated in the third space.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The technology disclosed herein relates to impact tools. [Background technology]

[0002] In the technical field related to impact tools, an impact tool as disclosed in Patent Document 1 is known. The impact tool disclosed in Patent Document 1 includes a spindle and a hammer disposed around the spindle. Lubricating oil is contained in the internal space of the spindle. The lubricating oil is supplied between the spindle and the hammer from the internal space of the spindle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-037560 Summary of the Invention [Problem to be solved by the invention]

[0004] If the lubricating oil leaks from the internal space of the spindle, the amount of lubricating oil supplied between the spindle and the hammer will decrease, which may result in severe wear or seizure of at least one of the spindle and the hammer, shortening the life of the impact tool.

[0005] The technology disclosed in this specification aims to prevent the life of an impact tool from being shortened. [Means for solving the problem]

[0006] This specification discloses an impact tool. The impact tool may include a motor, a spindle at least a part of which is disposed forward of the motor and rotated by the motor, a hammer disposed around the spindle, an anvil at least a part of which is disposed forward of the spindle and struck in the rotational direction by the hammer, and an internal space formed inside the spindle so as to extend forward from an opening provided on a rear end surface of the spindle. The internal space may include a first space having a first inner diameter connected to the opening, a second space having a second inner diameter smaller than the first inner diameter provided forward of the first space, and a third space having a third inner diameter larger than the second inner diameter connected to a front end of the second space. A lubricant may be stored in the third space. Effect of the Invention

[0007] According to the technology disclosed in this specification, the shortening of the life of an impact tool is suppressed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a front perspective view showing an impact tool according to an embodiment. [Diagram 2] FIG. 2 is a side view showing an upper portion of the impact tool according to the embodiment. [Diagram 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 an upper portion of the impact tool according to the embodiment. [Diagram 5] FIG. 5 is an enlarged view of a portion of FIG. [Figure 6] FIG. 6 is a front perspective view showing an upper portion of the impact tool according to the embodiment. [Figure 7] FIG. 7 is an exploded perspective view showing an upper portion of the impact tool according to the embodiment, seen from the right front. [Figure 8] FIG. 8 is an exploded perspective view showing an upper portion of the impact tool according to the embodiment, seen from the left front. [Figure 9]FIG. 9 is a side view showing an upper portion of the impact tool according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one or more embodiments, the impact tool may include a motor, a spindle at least a portion of which is disposed forward of the motor and rotated by the motor, a hammer disposed around the spindle, an anvil at least a portion of which is disposed forward of the spindle and struck in the rotational direction by the hammer, and an internal space formed inside the spindle so as to extend forward from an opening provided on a rear end surface of the spindle. The internal space may include a first space having a first inner diameter connected to the opening, a second space having a second inner diameter smaller than the first inner diameter provided forward of the first space, and a third space having a third inner diameter larger than the second inner diameter connected to a front end of the second space. A lubricant may be stored in the third space.

[0010] In the above configuration, a second space having a small inner diameter is provided between the first space and the third space. Since the second space functions as a flow resistance portion for the lubricating oil, the lubricating oil contained in the third space is prevented from moving to the first space via the second space. Therefore, the lubricating oil contained in the third space is prevented from leaking through the opening. This prevents the amount of lubricating oil supplied between the spindle and the hammer from being reduced. Therefore, wear or seizure of the spindle and the hammer is prevented, and the life of the impact tool is prevented from being shortened.

[0011] In one or more embodiments, a forward-facing step surface may be provided at the boundary between the front end of the second space and the rear end of the third space.

[0012] In the above configuration, the step surface prevents the lubricant oil contained in the third space from migrating to the second space.

[0013] In one or more embodiments, the third inner diameter may be smaller than the first inner diameter.

[0014] In the above configuration, a decrease in the strength of the spindle is suppressed.

[0015] In one or more embodiments, the spindle may include a first supply port provided on an outer peripheral surface of the spindle for supplying lubricating oil from the third space to between the spindle and the hammer.

[0016] In the above configuration, the lubricating oil in the third space is supplied between the spindle and the hammer through the first supply port.

[0017] In one or more embodiments, the nozzle may include a first flow passage provided in the spindle and connecting the third space and the first supply port.

[0018] In the above configuration, when the spindle rotates, centrifugal force causes the lubricating oil in the third space to be supplied to the first supply port via the first flow path.

[0019] In one or more embodiments, the hammer may have a body portion and an inner cylinder portion protruding rearwardly from the body portion and having an inner circumferential surface in contact with an outer circumferential surface of the spindle. The first supply port may supply lubricating oil between the outer circumferential surface of the spindle and the inner circumferential surface of the inner cylinder portion of the hammer.

[0020] In the above configuration, lubricating oil is supplied from the third space between the outer peripheral surface of the spindle and the inner peripheral surface of the inner cylindrical portion of the hammer, thereby suppressing wear or seizure between the outer peripheral surface of the spindle and the inner peripheral surface of the inner cylindrical portion of the hammer.

[0021] In one or more embodiments, a plurality of first supply ports may be provided in the circumferential direction.

[0022] In the above configuration, since a plurality of first supply ports are provided in the circumferential direction, the lubricating oil is evenly supplied between the outer circumferential surface of the spindle and the inner circumferential surface of the inner cylindrical portion of the hammer.

[0023] In one or more embodiments, the impact tool may include a second supply port provided at a front end of the spindle for supplying lubricant from the third space to between the spindle and the anvil.

[0024] In the above configuration, the lubricating oil is supplied between the spindle and the anvil from the third space, thereby suppressing wear of the spindle and the anvil.

[0025] In one or more embodiments, the spindle may have a spindle shaft portion and a spindle protrusion portion provided at a front end portion of the spindle shaft portion. The anvil may have an anvil recess provided at a rear end surface of the anvil and in which the spindle protrusion portion is disposed. The hammer may be disposed around the spindle shaft portion. The second supply port may be provided in the spindle protrusion portion.

[0026] In the above configuration, lubricating oil is supplied from the third space between the surface of the spindle convex portion and the inner surface of the anvil concave portion, thereby suppressing wear between the surface of the spindle convex portion and the inner surface of the anvil concave portion.

[0027] In one or more embodiments, the spindle may have a receiving recess recessed rearwardly from a front end surface of the forward-facing spindle protrusion. The anvil may have a protrusion protruding rearwardly from a bottom surface of the rear-facing anvil recess. The protrusion may be disposed inside the receiving recess.

[0028] In the above configuration, the overall length of the impact tool is prevented from increasing, while the contact area between the spindle convex portion and the anvil concave portion is prevented from decreasing. If the contact area between the spindle convex portion and the anvil concave portion becomes smaller, the stress (contact surface pressure) applied to at least one of the spindle convex portion and the anvil concave portion increases, which may result in severe wear or seizure of at least one of the spindle convex portion and the anvil concave portion. Since the contact area between the spindle convex portion and the anvil concave portion is prevented from decreasing, wear or seizure of the spindle convex portion and the anvil concave portion is prevented. Therefore, the life of the impact tool is prevented from being shortened.

[0029] In one or more embodiments, the second supply port may be provided in a bottom surface of the receiving recess facing forward.

[0030] In the above-described configuration, the lubricating oil is evenly supplied to both the surface of the spindle protrusion and the inner surface of the anvil recess.

[0031] In one or more embodiments, the protrusion may be tapered, decreasing in outer diameter in a rearward direction.

[0032] In the above-described configuration, a protrusion is provided that matches the shape of the rear end of the tool hole provided in the anvil.

[0033] In one or more embodiments, the rear end of the protrusion may be disposed forward of the rear face of the anvil.

[0034] In the above-described configuration, since the protrusion does not protrude from the rear end surface of the anvil, it is not necessary to make the accommodating recess excessively deep.

[0035] In one or more embodiments, the impact tool may include a hammer case that supports an anvil via an anvil bearing. The anvil may have a tool hole into which at least a portion of the socket is inserted. A socket holder that holds the socket via a connecting member may be attached to the hammer case. The socket holder may have an arc portion that is hooked onto a hook portion provided on the hammer case, a first holding portion provided at one end of the arc portion, a second holding portion provided at the other end of the arc portion, and an elastic ring that fixes the first holding portion and the second holding portion. The connecting member may be connected to each of the first holding portion and the second holding portion.

[0036] In the above configuration, because the front part of the socket is held by the socket holder, even if the middle part of the socket is broken, the front part of the socket is prevented from falling. Also, because the first holding part and the second holding part are fixed by the elastic ring, the structure of the socket holder is simplified and the cost of the socket holder is reduced.

[0037] In one or more embodiments, the first retaining portion may be provided to protrude forward from one end of the arc portion, and the second retaining portion may be provided to protrude forward from the other end of the arc portion.

[0038] In the above configuration, the worker can attach the elastic rings around the first holding portion and the second holding portion from the front of the first holding portion and the second holding portion.

[0039] In one or more embodiments, the first retaining portion may have a first opening, the second retaining portion may have a second opening, and the connecting member may be inserted into each of the first and second openings.

[0040] In the above configuration, the socket holder and the connecting member are connected together by inserting the connecting member into each of the first opening and the second opening.

[0041] [Embodiment] The 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.

[0042] In the embodiment, the direction parallel to the rotation axis AX of the motor 6 is referred to as the axial direction, the direction circumferential 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.

[0043] The rotation axis AX extends in the front-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 is appropriately referred to as the radially inner side, and a position farther from or away from the rotation axis AX is appropriately referred to as the radially outer side.

[0044] <Impact tools> Fig. 1 is a front perspective view showing an impact tool 1 according to an embodiment. Fig. 2 is a side view showing an upper part of the impact tool 1 according to an embodiment. Fig. 3 is a vertical cross-sectional view showing an upper part of the impact tool 1 according to an embodiment. Fig. 4 is a horizontal cross-sectional view showing an upper part of the impact tool 1 according to an embodiment.

[0045] In the embodiment, the impact tool 1 is an impact driver, which is a type of screw tightening tool. The impact tool 1 includes a housing 2, a rear cover 3, a hammer case 4, a bearing box 24, a hammer case cover 51, a motor 6, a reduction mechanism 7, a spindle 8, a striking mechanism 9, an anvil 10, a tool holding mechanism 11, a fan 12, a battery mounting portion 13, a trigger lever 14, a forward / reverse switching lever 15, a light assembly 18, and a light cover 52.

[0046] The housing 2 is made of synthetic resin. In this embodiment, the housing 2 is made of nylon. The housing 2 includes a left housing 2L and a right housing 2R disposed to the right of the left housing 2L. The left housing 2L and the right housing 2R are fixed together by a plurality of screws 2S. The housing 2 is composed of a pair of half housings.

[0047] The housing 2 has a motor accommodating portion 21, a grip portion 22, and a battery holding portion 23.

[0048] The motor accommodating portion 21 accommodates the motor 6. The motor accommodating portion 21 accommodates at least a portion of the hammer case 4. The motor accommodating portion 21 is cylindrical.

[0049] The grip portion 22 is held by an operator. The grip portion 22 extends downward from the motor housing portion 21. The trigger lever 14 is provided on an upper portion of the grip portion 22.

[0050] The battery holding portion 23 holds the battery pack 25 via the battery attachment portion 13. The battery holding portion 23 is connected to a lower end portion of the grip portion 22. The outer dimensions of the battery holding portion 23 are larger than the outer dimensions of the grip portion 22 in both the front-rear direction and the left-right direction.

[0051] The rear cover 3 is positioned so as to cover the opening at the rear end of the motor accommodating portion 21. The rear cover 3 is positioned behind the motor accommodating portion 21. The rear cover 3 accommodates at least a portion of the fan 12. The fan 12 is positioned inside the rear cover 3. The rear cover 3 holds a rear rotor bearing 37. The rear cover 3 is made of synthetic resin. The rear cover 3 is fixed to the rear end of the motor accommodating portion 21 with two screws 3S.

[0052] The motor accommodating portion 21 has an air intake port 19. The rear cover 3 has an air exhaust port 20. Air in the external space of the housing 2 flows into the internal space of the housing 2 through the air intake port 19. Air in the internal space of the housing 2 flows out to the external space of the housing 2 through the air exhaust port 20.

[0053] The hammer case 4 accommodates at least a part of the reduction mechanism 7, the spindle 8, the impact mechanism 9, and at least a part of the anvil 10. The hammer case 4 is made of metal. In the embodiment, the hammer case 4 is made of aluminum. The hammer case 4 is cylindrical. The hammer case 4 includes a large cylinder portion 4A, a small cylinder portion 4B, and a connecting portion 4C. The small cylinder portion 4B is disposed forward of the large cylinder portion 4A. The front end portion of the large cylinder portion 4A and the rear end portion of the small cylinder portion 4B are connected via the connecting portion 4C. The connecting portion 4C is annular. The outer diameter of the large cylinder portion 4A is larger than the outer diameter of the small cylinder portion 4B. The inner diameter of the large cylinder portion 4A is larger than the inner diameter of the small cylinder portion 4B.

[0054] The bearing box 24 accommodates at least a part of the reduction gear mechanism 7. The bearing box 24 holds the front rotor bearing 38 and the spindle bearing 44. The bearing box 24 is made of metal. The bearing box 24 is fixed to the rear of the hammer case 4. The bearing box 24 has a rear annular portion 24A and a front annular portion 24B. The front annular portion 24B is disposed forward of the rear annular portion 24A. The front end of the rear annular portion 24A and the rear end of the front annular portion 24B are connected via a connecting portion 24C. The connecting portion 24C is annular. The outer diameter of the rear annular portion 24A is smaller than the outer diameter of the front annular portion 24B. The inner diameter of the rear annular portion 24A is smaller than the inner diameter of the front annular portion 24B. The bearing box 24 and the hammer case 4 may be fixed by a screw portion or by fitting (light fitting). For example, a screw thread may be formed on the outer periphery of the front annular portion 24B, and a screw groove may be formed on the inner periphery of the large cylinder portion 4A. The bearing box 24 and the hammer case 4 may be fixed by coupling the screw thread of the front annular portion 24B with the screw groove of the large cylinder portion 4A. The bearing box 24 and the hammer case 4 may be fixed by fitting the front annular portion 24B into the large cylinder portion 4A. The front rotor bearing 38 is disposed radially inward of the rear annular portion 24A. The spindle bearing 44 is disposed radially inward of the connection portion 24C.

[0055] The hammer case 4 is sandwiched between the left housing 2L and the right housing 2R. A rear portion of the hammer case 4 is housed in the motor housing portion 21. The hammer case 4 is connected to a front portion of the motor housing portion 21. A bearing box 24 is fixed to each of the motor housing portion 21 and the hammer case 4.

[0056] The hammer case cover 51 protects the hammer case 4. The hammer case cover 51 suppresses contact between the hammer case 4 and objects around the hammer case 4. The hammer case cover 51 is disposed so as to cover the outer peripheral surface of the large cylinder portion 4A. The hammer case cover 51 may be omitted.

[0057] The motor 6 is a power source of 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 accommodating portion 21. At least a portion of the rotor 27 is disposed inside the stator 26. The rotor 27 rotates relative to the stator 26. The rotor 27 rotates about a rotation axis AX extending in the front-rear direction.

[0058] The stator 26 includes a stator core 28 , a rear insulator 29 , a front insulator 30 , and a coil 31 .

[0059] The stator core 28 includes a plurality of stacked steel plates. The steel plates are made of a metal whose main component is iron. The stator core 28 is cylindrical. The stator core 28 is disposed radially outward of the rotor 27. The stator core 28 has a plurality of teeth that support the coils 31.

[0060] The rear insulator 29 and the front insulator 30 are each an electrical insulating member made of synthetic resin. The rear insulator 29 and the front insulator 30 each electrically insulate the stator core 28 from the coil 31. The rear insulator 29 is fixed to the rear of the stator core 28. The front insulator 30 is fixed to the front of the stator core 28. The rear insulator 29 is arranged so as to cover a portion of the surface of the teeth. The front insulator 30 is arranged so as to cover a portion of the surface of the teeth.

[0061] The coil 31 is attached to the stator core 28 via the rear insulator 29 and the front insulator 30. A plurality of coils 31 are arranged. The coils 31 are arranged around the teeth of the stator core 28 via the rear insulator 29 and the front insulator 30. The coils 31 and the stator core 28 are electrically insulated by the front insulator 30 and the rear insulator 29. The multiple coils 31 are connected via fusing terminals 36.

[0062] The rotor 27 rotates about a rotation axis AX. The rotor 27 includes a rotor core 32, a rotor shaft 33, a rotor magnet 34A, and a sensor magnet 34B.

[0063] The rotor core 32 and the rotor shaft 33 are each made of steel. In this embodiment, the rotor core 32 and the rotor shaft 33 are integral with each other. A rear portion of the rotor shaft 33 protrudes rearward from a rear end surface of the rotor core 32. A front portion of the rotor shaft 33 protrudes forward from a front end surface of the rotor core 32.

[0064] The rotor magnet 34A is fixed to the rotor core 32. In the embodiment, the rotor magnet 34A is disposed around the rotor core 32. The sensor magnet 34B is fixed to the rotor core 32. In the embodiment, the sensor magnet 34B is disposed on the front end surface of the rotor core 32.

[0065] A sensor board 35 is attached to the front insulator 30. The sensor board 35 is fixed to the front insulator 30 with screws 30S. The sensor board 35 has an annular circuit board and a rotation detection element supported by the circuit board. At least a portion of the sensor board 35 faces the front end surface of the sensor magnet 34B. The rotation detection element detects the position of the sensor magnet 34B, thereby detecting the position of the rotor 27 in the rotational direction.

[0066] The rear end of the rotor shaft 33 is rotatably supported by a rear rotor bearing 37. The front end of the rotor shaft 33 is rotatably supported by a front rotor bearing 38. The rear rotor bearing 37 is held by the rear cover 3. The front rotor bearing 38 is held by the bearing box 24.

[0067] The front end of the rotor shaft 33 is disposed in the internal space of the hammer case 4 through an opening 59 provided in the rear annular portion 24 A of the bearing box 24 .

[0068] A pinion gear 41 is fixed to a front end portion 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 connects the rotor shaft 33 and the spindle 8. A gear of the reduction mechanism 7 is driven by the rotor 27. The reduction mechanism 7 transmits the rotation of the rotor 27 to the spindle 8. The reduction mechanism 7 rotates the spindle 8 at a rotational speed lower than the rotational speed of the rotor shaft 33. The reduction mechanism 7 is disposed forward of the stator 26. The reduction mechanism 7 includes a planetary gear mechanism.

[0070] 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 by the spindle 8 via a pin 42P. The spindle 8 is rotated by the planetary gear 42. The internal gear 43 has internal teeth that mesh with the planetary gear 42.

[0071] The internal gear 43 is fixed to the large cylindrical portion 4A of the hammer case 4. The internal gear 43 is always non-rotatable relative to the hammer case 4.

[0072] 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.

[0073] The spindle 8 is rotated about the rotation axis AX by the motor 6. The spindle 8 is rotated by the rotor 27. The spindle 8 rotates by the rotational force of the rotor 27 transmitted via the reduction mechanism 7. The spindle 8 transmits the rotational force of the motor 6 to the anvil 10 via a ball 48 and a hammer 47. At least a portion of the spindle 8 is disposed forward 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. At least a portion of the spindle 8 is disposed rearward of the anvil 10.

[0074] The spindle 8 has a spindle shaft portion 8A, a first flange portion 8B, a second flange portion 8C, a connecting portion 8D, and a spindle protrusion portion 8F.

[0075] The spindle shaft portion 8A is rod-shaped and long in the front-rear direction. The central axis of the spindle shaft portion 8A and the rotation axis AX are aligned. The first flange portion 8B extends radially outward from the rear end of the outer circumferential surface of the spindle shaft portion 8A. The second flange portion 8C is disposed rearward of the first flange portion 8B. The second flange portion 8C is annular. The connecting portion 8D connects a portion of the first flange portion 8B and a portion of the second flange portion 8C. The spindle protrusion 8F protrudes forward from the front end of the spindle shaft portion 8A. The front end of the pin 42P is supported by the first flange portion 8B. The rear end of the pin 42P is supported by the second flange portion 8C. The planetary gear 42 is disposed between the first flange portion 8B and the second flange portion 8C. The planetary gear 42 is rotatably supported by the first flange portion 8B and the second flange portion 8C via the pin 42P. The spindle bearing 44 is disposed inside a cylindrical portion of the spindle 8 that protrudes rearward from the rear surface of the second flange portion 8C. The spindle bearing 44 holds the cylindrical portion of the spindle 8. The spindle bearing 44 is held in the bearing box 24.

[0076] The striking mechanism 9 is driven by the motor 6. The rotational force of the motor 6 is transmitted to the striking mechanism 9 via the reduction mechanism 7 and the spindle 8. The striking mechanism 9 strikes the anvil 10 in the rotational direction based on the rotational force of the spindle 8 rotated by the motor 6. The striking mechanism 9 has a hammer 47, a ball 48, a coil spring 49, and a washer 50. The striking mechanism 9 including the hammer 47, the ball 48, the coil spring 49, and the washer 50 is housed in the large cylinder portion 4A of the hammer case 4.

[0077] The hammer 47 is disposed forward of the reduction mechanism 7. The hammer 47 is disposed around the spindle 8. The hammer 47 is disposed around the spindle shaft portion 8A. The hammer 47 is held by the spindle shaft portion 8A. The ball 48 is disposed between the spindle 8 and the hammer 47.

[0078] The hammer 47 has a body portion 47A, an outer cylinder portion 47B, an inner cylinder portion 47C, and a hammer protrusion portion 47D. The body portion 47A is disposed around the spindle shaft portion 8A. The body portion 47A is annular. The outer cylinder portion 47B and the inner cylinder portion 47C each protrude rearward from the body portion 47A. The outer cylinder portion 47B is disposed radially outward from the inner cylinder portion 47C. A recess 47E is defined by the rear surface of the body portion 47A, the inner peripheral surface of the outer cylinder portion 47B, and the outer peripheral surface of the inner cylinder portion 47C. The recess 47E is provided so as to be recessed forward from the rear end portion of the hammer 47. The recess 47E is ring-shaped. The spindle shaft portion 8A is disposed radially inward from the body portion 47A and the inner cylinder portion 47C. The inner cylinder portion 47C has an inner circumferential surface 47S that contacts the outer circumferential surface 8S of the spindle shaft portion 8A. The hammer protrusions 47D protrude forward from the body portion 47A. Two hammer protrusions 47D are provided.

[0079] 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.

[0080] The washer 50 is disposed inside the recess 47E. The washer 50 is supported by the hammer 47 via a plurality of balls 54. The balls 54 are disposed forward of the washer 50. The balls 54 are disposed between the rear surface of the body portion 47A and the front surface of the washer 50.

[0081] The coil spring 49 is disposed around the spindle shaft portion 8A. The rear end of the coil spring 49 is supported by the first flange portion 8B. The front end of the coil spring 49 is disposed inside the recess 47E and supported by a washer 50. The coil spring 49 constantly generates an elastic force that moves the hammer 47 forward.

[0082] The ball 48 is made of a metal such as steel. The ball 48 is disposed between the spindle shaft portion 8A and the body portion 47A. The spindle shaft portion 8A has a spindle groove 8G in which at least a portion of the ball 48 is disposed. The spindle groove 8G is provided on a portion of the outer circumferential surface of the spindle shaft portion 8A. The hammer 47 has a hammer groove 47G in which at least a portion of the ball 48 is disposed. The hammer groove 47G is provided on a portion of the inner circumferential surfaces of the body portion 47A and the inner cylinder portion 47C.

[0083] Two balls 48 are provided. Two spindle grooves 8G are provided on the outer peripheral surface of the spindle shaft portion 8A. Two hammer grooves 47G are provided on the inner peripheral surfaces of the body portion 47A and the inner cylinder portion 47C. One ball 48 is disposed between one spindle groove 8G and one hammer groove 47G. The other ball 48 is disposed between the other spindle groove 8G and the other hammer groove 47G. The ball 48 can roll on the inside of the spindle groove 8G and the inside of the hammer groove 47G. The hammer 47 can move along with the ball 48. The spindle 8 and the hammer 47 can move relative to each other in the axial direction and the rotational direction within a movable range defined by the spindle groove 8G and the hammer groove 47G.

[0084] The anvil 10 is disposed forward of the motor 6. The anvil 10 is an output part of the impact tool 1 that rotates based on the rotational force of the rotor 27. At least a portion of the anvil 10 is disposed forward of the spindle 8. At least a portion of the anvil 10 is disposed forward of the hammer 47. The anvil 10 is struck by the hammer 47 in the rotational direction.

[0085] The anvil 10 has an anvil shaft portion 10A and an anvil protrusion portion 10B. The anvil shaft portion 10A is rod-shaped and long in the front-rear direction. The central axis of the anvil shaft portion 10A coincides with the rotation axis AX. The anvil protrusion portion 10B is provided at the rear end portion of the anvil shaft portion 10A. The anvil protrusion portion 10B protrudes radially outward from the rear end portion of the anvil shaft portion 10A. Two anvil protrusion portions 10B are provided.

[0086] A tool hole 10C is provided in the front end surface of the anvil 10. An anvil recess 10D is provided in the rear end surface of the anvil 10. The tool hole 10C is formed to extend rearward from the front end surface of the anvil shaft portion 10A. A tool tip is inserted into the tool hole 10C. The tool tip is attached to the anvil 10. The anvil recess 10D is provided to be recessed forward from the rear end surface of the anvil 10. A spindle protrusion 8F is disposed in the anvil recess 10D.

[0087] The anvil 10 is rotatably supported by the anvil bearing 46. The rotation axis of the anvil 10, the rotation axis of the hammer 47, the rotation axis of the spindle 8, and the rotation axis AX of the motor 6 are aligned. The anvil 10 rotates around the rotation axis AX. The anvil bearing 46 is disposed around the anvil shaft portion 10A. An O-ring 45 is disposed between the anvil bearing 46 and the anvil shaft portion 10A. The anvil bearing 46 is disposed inside the small cylinder portion 4B of the hammer case 4. The anvil bearing 46 is held by the small cylinder portion 4B of the hammer case 4. The hammer case 4 supports the anvil 10 via the anvil bearing 46. The anvil bearing 46 rotatably supports the front portion of the anvil shaft portion 10A. In the embodiment, two anvil bearings 46 are disposed in the front-rear direction.

[0088] A washer 56 and a support member 57 are arranged in front of the anvil protrusion 10B. The support member 57 is arranged so as to contact the rear surface of the connection portion 4C and the rear surface of the outer ring of the anvil bearing 46. The support member 57 is ring-shaped. The support member 57 prevents the anvil bearing 46 from slipping out rearward from the small cylinder portion 4B. The support member 57 also prevents contact between the front surface of the anvil protrusion 10B and the hammer case 4. The washer 56 supports the support member 57 from the rear. The washer 56 is arranged in a groove provided on the inner surface of the large cylinder portion 4A.

[0089] The hammer protrusion 47D can come into contact with the anvil protrusion 10B. When the motor 6 is driven in a state in which the hammer protrusion 47D and the anvil protrusion 10B are in contact with each other, the anvil 10 rotates together with the hammer 47 and the spindle 8.

[0090] The anvil 10 is struck in the rotational direction by the hammer 47. For example, in a screw tightening operation, when the load acting on the anvil 10 becomes high, a situation may occur in which the anvil 10 cannot be rotated by the load of the coil spring 49 alone. When the anvil 10 cannot be rotated by the load of the coil spring 49 alone, the rotation of the anvil 10 and the hammer 47 stops. The spindle 8 and the hammer 47 can move relative to each other in the axial direction and the circumferential direction via the ball 48. Even if the rotation of the hammer 47 stops, the rotation of the spindle 8 continues by the power generated by the motor 6. When the spindle 8 rotates while the rotation of the hammer 47 is stopped, the ball 48 moves backward while being guided by each of the spindle groove 8G and the hammer groove 47G. When the spindle 8 rotates while the rotation of the hammer 47 is stopped, the outer peripheral surface 8S of the spindle 8 and the inner peripheral surface 47S of the hammer 47 slide against each other. The hammer 47 receives a force from the ball 48 and moves rearward along with the ball 48. That is, the hammer 47 moves rearward as the spindle 8 rotates while the rotation of the anvil 10 is stopped. As the hammer 47 moves rearward, the contact between the hammer protrusion 47D and the anvil protrusion 10B is released.

[0091] As described above, the coil spring 49 constantly generates an elastic force that moves the hammer 47 forward. The hammer 47 that has moved backward moves forward due to the elastic force of the coil spring 49. When the hammer 47 moves forward, it receives a force in the rotational direction from the ball 48. That is, the hammer 47 moves forward while rotating. When the hammer 47 moves forward while rotating, the hammer 47 comes into contact with the anvil protrusion 10B while rotating. As a result, the anvil protrusion 10B is struck in the rotational direction by the hammer protrusion 47D of the hammer 47. 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.

[0092] The tool holding mechanism 11 is disposed around the front part of the anvil 10. The tool holding mechanism 11 holds a tool bit inserted into a tool hole 10C of the anvil 10. The tool holding mechanism 11 is capable of attaching and detaching the tool bit.

[0093] The tool holding mechanism 11 has a ball 71 , a leaf spring 72 , a sleeve 73 , a coil spring 74 , and a positioning member 75 .

[0094] The anvil 10 has a support recess 76 that supports the ball 71. The support recess 76 is formed in the outer surface of the anvil shaft portion 10A. In the embodiment, two support recesses 76 are formed in the anvil shaft portion 10A.

[0095] The balls 71 are movably supported by the anvil 10. The balls 71 are disposed in the support recesses 76. The balls 71 are disposed in one support recess 76.

[0096] A through hole connecting the inner surface of the support recess 76 and the inner surface of the tool hole 10C is formed in the anvil shaft portion 10A. The diameter of the ball 71 is smaller than the diameter of the through hole. With the ball 71 supported by the support recess 76, it is disposed inside the tool hole 10C via at least a part of the ball 71. The ball 71 can fix a tool bit inserted into the tool hole 10C. The ball 71 is movable between an engagement position where the tool bit is fixed and a release position where the fixation of the tool bit is released.

[0097] The leaf spring 72 generates an elastic force that moves the ball 71 to the engagement position. The leaf spring 72 is disposed around the anvil shaft portion 10A. The leaf spring 72 generates an elastic force that moves the ball 71 forward.

[0098] The sleeve 73 is a cylindrical member. The sleeve 73 is disposed around the anvil shaft portion 10A. The sleeve 73 is axially movable around the anvil shaft portion 10A. The sleeve 73 can prevent the ball 71, which is disposed at the engagement position, from escaping from the engagement position. The sleeve 73 can be moved in the axial direction to change the state of the ball 71 from the engagement position to a release position.

[0099] The sleeve 73 is movable around the anvil shaft portion 10A between a blocking position where the balls 71 are blocked from moving radially outward and an allowing position where the balls 71 are allowed to move radially outward.

[0100] By disposing the sleeve 73 in the blocking position, the ball 71 disposed in the engagement position is prevented from moving radially outward. In other words, by disposing the sleeve 73 in the blocking position, the ball 71 disposed in the engagement position is prevented from escaping from the engagement position. By disposing the sleeve 73 in the blocking position, the tool bit is maintained in a state where it is fixed by the ball 71.

[0101] By moving the sleeve 73 to the permissible position, the ball 71 disposed at the engagement position is permitted to move radially outward. By moving the sleeve 73 to the permissible position, the ball 71 is changed to a state in which it can be moved from the engagement position to the release position. In other words, by placing the sleeve 73 at the permissible position, the ball 71 disposed at the engagement position is permitted to escape from the engagement position. By placing the sleeve 73 at the permissible position, the state in which the bit is fixed by the ball 71 can be released.

[0102] The coil spring 74 generates an elastic force to move the sleeve 73 to the blocking position. The coil spring 74 is disposed around the anvil shaft portion 10A. The blocking position is set rearward of the allowable position. The coil spring 74 generates an elastic force to move the sleeve 73 rearward.

[0103] The positioning member 75 is a ring-shaped member fixed to the outer surface of the anvil shaft portion 10A. The positioning member 75 is fixed at a position capable of opposing the rear end of the sleeve 73. The positioning member 75 positions the sleeve 73 at the blocking position. The sleeve 73, which is given an elastic force moving rearward by the coil spring 74, comes into contact with the positioning member 75, and is positioned at the blocking position.

[0104] The fan 12 is disposed behind the stator 26 of the motor 6. The fan 12 generates an airflow for cooling the motor 6. The fan 12 is fixed to at least a part of the rotor 27. The fan 12 is fixed to the rear of the rotor shaft 33 via a bush 12A. The fan 12 is disposed between the rear rotor bearing 37 and the stator 26. The fan 12 rotates with the rotation of the rotor 27. The rotor shaft 33 rotates, and the fan 12 rotates together with the rotor shaft 33. As the fan 12 rotates, air in the external space of the housing 2 flows into the internal space of the housing 2 through the intake port 19. The air that has flowed into the internal space of the housing 2 circulates through the internal space of the housing 2, thereby cooling the motor 6. As the fan 12 rotates, the air that has circulated through the internal space of the housing 2 flows out through the exhaust port 20 into the external space of the housing 2.

[0105] The battery mounting section 13 is disposed at the lower part of the battery holding section 23. The battery mounting section 13 is connected to the battery pack 25. The battery pack 25 is mounted to the battery mounting section 13. The battery pack 25 is detachable from the battery mounting section 13. The battery pack 25 is mounted to the battery mounting section 13 by being inserted into the battery mounting section 13 from the front of the battery holding section 23. The battery pack 25 is removed from the battery mounting section 13 by being removed forward from the battery mounting section 13. The battery pack 25 includes a secondary battery. In the embodiment, the battery pack 25 includes a rechargeable lithium ion battery. By being mounted to the battery mounting section 13, the battery pack 25 can supply power to the impact tool 1. The motor 6 is driven based on the power supplied from the battery pack 25.

[0106] The trigger lever 14 is provided on the grip portion 22. The trigger lever 14 is operated by an operator to start the motor 6. By operating the trigger lever 14, the motor 6 is switched between being driven and being stopped.

[0107] The forward / reverse switching lever 15 is provided on the upper part of the grip portion 22. The forward / reverse switching lever 15 is operated by an operator. By operating the forward / reverse switching lever 15, the rotation direction of the motor 6 is switched from one of the forward direction and the reverse direction to the other. By switching the rotation direction of the motor 6, the rotation direction of the spindle 8 is switched.

[0108] The light assembly 18 emits illumination light. The light assembly 18 illuminates the anvil 10 and the periphery of the anvil 10 with illumination light. The light assembly 18 illuminates the front of the anvil 10 with illumination light. The light assembly 18 also illuminates the tip tool attached to the anvil 10 and the periphery of the tip tool with illumination light. In the embodiment, the light assembly 18 is disposed around the small cylinder portion 4B. The light assembly 18 has a circuit board 18A, a light-emitting element 18B supported by the circuit board 18A, and an optical member 18C through which the light emitted from the light-emitting element 18B passes. The optical member 18C is ring-shaped.

[0109] The light cover 52 protects the light assembly 18. The light cover 52 prevents the light assembly 18 from contacting with objects surrounding the light assembly 18. The light cover 52 is disposed around the optical member 18C.

[0110] <Spindle internal space> Fig. 5 is an enlarged view of a portion of Fig. 3. As shown in Figs. 3, 4, and 5, the spindle 8 has an internal space 60. An opening is provided in the rear end surface of the spindle 8. The internal space 60 is formed inside the spindle 8 so as to extend forward from the opening provided in the rear end surface of the spindle 8.

[0111] The internal space 60 includes a first space 61, a second space 62, a third space 63, a fourth space 64, and a fifth space 65. The first space 61 is connected to an opening in the rear end surface of the spindle 8. A front end of the pinion gear 41 is inserted into the rear end of the first space 61 through an opening in the rear end surface of the spindle 8. The second space 62 is provided forward of the first space 61. The third space 63 is provided forward of the second space 62. The fourth space 64 is provided forward of the third space 63. The fifth space 65 is provided forward of the fourth space 64.

[0112] Each of the first space 61, the second space 62, the third space 63, the fourth space 64, and the fifth space 65 is substantially cylindrical. In a cross section perpendicular to the rotation axis AX, each of the first space 61, the second space 62, the third space 63, the fourth space 64, and the fifth space 65 is circular. The central axis of the first space 61, the central axis of the second space 62, the central axis of the third space 63, the central axis of the fourth space 64, and the central axis of the fifth space 65 substantially coincide with the rotation axis AX.

[0113] The second inner diameter D2 indicating the inner diameter of the second space 62 is smaller than the first inner diameter D1 indicating the inner diameter of the first space 61. The third inner diameter D3 indicating the inner diameter of the third space 63 is larger than the second inner diameter D2 indicating the inner diameter of the second space 62. The third inner diameter D3 indicating the inner diameter of the third space 63 is smaller than the first inner diameter D1 indicating the inner diameter of the first space 61. The third inner diameter D3 indicating the inner diameter of the third space 63 is larger than the fourth inner diameter D4 indicating the inner diameter of the fourth space 64. The fifth inner diameter D5 indicating the inner diameter of the fifth space 65 is smaller than the fourth inner diameter D4 indicating the inner diameter of the fourth space 64. The second inner diameter D2 indicating the inner diameter of the second space 62 is equal to the fourth inner diameter D4 indicating the inner diameter of the fourth space 64. That is, the relationship of [D1>D3>D2=D4>D5] is established.

[0114] In the front-rear direction, the dimension of the third space 63 is larger than the dimension of the second space 62 and the dimension of the fourth space 64. In the front-rear direction, the dimension of the third space 63 is smaller than the dimension of the first space 61 and the dimension of the fifth space 65. In the front-rear direction, the dimension of the fifth space 65 is larger than the dimension of the first space 61.

[0115] The rear end of the first space 61 is connected to an opening on the rear end face of the spindle 8. The front end of the first space 61 is connected to the rear end of the second space 62 via a tapered passage. The front end of the second space 62 is connected to the front end of the third space 63. A step surface 66 is provided at the boundary between the front end of the second space 62 and the rear end of the third space 63. The step surface 66 faces forward. The front end of the third space 63 is connected to the rear end of the fourth space 64 via a tapered passage. The front end of the fourth space 64 is connected to the rear end of the fifth space 65 via a tapered passage.

[0116] Lubricating oil is contained in the third space 63. The lubricating oil includes grease.

[0117] The spindle 8 has a first supply port 81 and a second supply port 82 .

[0118] The first supply port 81 is provided on the outer peripheral surface of the spindle shaft portion 8A. The first supply port 81 supplies the lubricating oil from the first space 61 between the spindle 8 and the hammer 47. In the embodiment, the first supply port 81 supplies the lubricating oil between the outer peripheral surface 8S of the spindle shaft portion 8A and the inner peripheral surface 47S of the inner cylinder portion 47C. The first supply port 81 is connected to the third space 63 via a first flow passage 91 formed inside the spindle shaft portion 8A. The first flow passage 91 is provided to extend radially outward from the third space 63 so as to connect the third space 63 and the first supply port 81. The lubricating oil contained in the third space 63 flows through the first flow passage 91 toward the first supply port 81 due to the centrifugal force of the spindle 8. The lubricating oil supplied from the third space 63 through the first flow passage 91 to the first supply port 81 is supplied between the outer circumferential surface 8S of the spindle shaft portion 8A and the inner circumferential surface 47S of the inner cylindrical portion 47C.

[0119] As described above, when the spindle 8 rotates while the hammer 47 is stopped from rotating, the outer peripheral surface 8S of the spindle 8 slides against the inner peripheral surface 47S of the hammer 47. By supplying lubricant between the outer peripheral surface 8S and the inner peripheral surface 47S, which are the sliding surfaces, wear or seizure of the outer peripheral surface 8S and the inner peripheral surface 47S is suppressed.

[0120] A plurality of first supply ports 81 are provided in the circumferential direction. In the embodiment, the first supply ports 81 include a first supply port 81A and a first supply port 81B provided at a position different from the first supply port 81A in the circumferential direction. In the front-rear direction, the position of the first supply port 81A and the position of the first supply port 81B are substantially the same. In the circumferential direction, the first supply port 81A and the first supply port 81B are disposed at positions different from each other by 180 degrees.

[0121] The relative angle between the first supply port 81A and the first supply port 81B in the circumferential direction is an example. The number of the first supply ports 81 does not have to be two, and may be one, or may be any number of three or more.

[0122] The second supply port 82 is provided at the front end of the spindle 8. The second supply port 82 supplies the lubricating oil from the third space 63 between the spindle 8 and the anvil 10. The front end of the fifth space 65 is connected to the second supply port 82. In the embodiment, the second supply port 82 is provided at the spindle protrusion 8F. The second supply port 82 supplies the lubricating oil between the surface of the spindle protrusion 8F and the inner surface of the anvil recess 10D. The lubricating oil supplied to the second supply port 82 from the third space 63 through the fourth space 64 and the fifth space 65 is supplied between the surface of the spindle protrusion 8F and the inner surface of the anvil recess 10D.

[0123] <Spindle convex part and anvil concave part> 5, the spindle 8 has a spindle shaft portion 8A and a spindle protrusion 8F protruding forward from a front end surface 8M of the spindle shaft portion 8A. The anvil 10 has an anvil recess 10D provided on a rear end surface 10L of the anvil 10, in which the spindle protrusion 8F is disposed.

[0124] The spindle 8 also has an accommodating recess 8K recessed rearward from a front end surface 8J of the spindle protrusion 8F. The front end surface 8J faces forward. The anvil 10 has a protrusion 10G protruding rearward from a bottom surface 10F of the anvil recess 10D. The bottom surface 10F faces rearward. The protrusion 10G is disposed inside the accommodating recess 8K. The second supply port 82 is provided in the bottom surface of the accommodating recess 8K facing forward.

[0125] The outer diameter of the protrusion 10G becomes smaller toward the rear. The protrusion 10G is tapered such that the outer diameter becomes smaller toward the rear. The inner diameter of the accommodating recess 8K becomes smaller toward the rear. The accommodating recess 8K is tapered such that the inner diameter becomes smaller toward the rear to match the shape of the protrusion 10G. The rear end surface 10H of the protrusion 10G is located forward of the rear end surface 10L of the anvil 10.

[0126] In the embodiment, the front end surface 8M of the spindle shaft portion 8A and the rear end surface 10L of the anvil 10 are in contact with each other. The outer peripheral surface 8L of the spindle protrusion 8F and the inner peripheral surface 10K of the anvil recess 10D are in contact with each other. The front end surface 8J of the spindle protrusion 8F and the bottom surface 10F of the anvil recess 10D face each other through a gap. The outer peripheral surface 10J of the protrusion 10G and the inner peripheral surface of the accommodating recess 8K are parallel. The outer peripheral surface 10J of the protrusion 10G and the inner peripheral surface of the accommodating recess 8K face each other through a gap. The rear end surface 10H of the protrusion 10G faces the second supply port 82. The rear end surface 10H of the protrusion 10G and the second supply port 82 are separated from each other.

[0127] <Socket holder> Fig. 6 is a front perspective view showing the upper part of the impact tool 1 according to the embodiment. Fig. 7 is an exploded perspective view showing the upper part of the impact tool 1 according to the embodiment from the right front. Fig. 8 is an exploded perspective view showing the upper part of the impact tool 1 according to the embodiment from the left front. Fig. 9 is a side view showing the upper part of the impact tool 1 according to the embodiment.

[0128] As shown in Fig. 9, a socket 200 may be attached to the anvil 10. A hexagonal hole is provided at the front end of the socket 200. An insertion portion is provided at the rear of the socket 200 to be inserted into the tool hole 10C of the anvil 10. With the head of a bolt placed in the hexagonal hole of the socket 200, the anvil 10 is rotated to tighten the bolt to the target.

[0129] The socket holder 100 is attached to the hammer case 4. The socket holder 100 holds the socket 200 via a connecting member 105. The socket holder 100 has an arc portion 103 that is hooked onto a hook portion 4F provided on the hammer case 4, a first holding portion 101 provided at one end of the arc portion 103, a second holding portion 102 provided at the other end of the arc portion 103, and an elastic ring 104 that fixes the first holding portion 101 and the second holding portion 102 together.

[0130] As shown in Figures 4 and 7, the hook portion 4F is provided on the small cylinder portion 4B of the hammer case 4. The hook portion 4F protrudes radially outward from the outer circumferential surface of the small cylinder portion 4B. The hook portion 4F is ring-shaped. A recess is provided on the inner circumferential surface of the arc portion 103 into which the hook portion 4F is inserted. By inserting the hook portion 4F into the inside of the recess of the arc portion 103, the arc portion 103 is hooked onto the hook portion 4F.

[0131] Each of the first holding portion 101 and the second holding portion 102 holds a connecting member 105. The first holding portion 101 is provided so as to protrude forward from one end of the arc portion 103. The second holding portion 102 is provided so as to protrude forward from the other end of the arc portion 103. Each of the first holding portion 101 and the second holding portion 102 is plate-shaped. The first holding portion 101 has a first opening 101A. The second holding portion 102 has a second opening 102A.

[0132] The elastic ring 104 fixes the first holding part 101 and the second holding part 102. An example of the elastic ring is a rubber ring. The elastic ring 104 is disposed so as to surround the first holding part 101 and the second holding part 102.

[0133] When mounting the socket holder 100 to the hammer case 4, the worker arranges the arc portion 103 around the small tube portion 4B in a state in which the arc portion 103 is elastically deformed so that the diameter of the arc portion 103 is expanded. After the arc portion 103 is arranged around the small tube portion 4B and the hook portion 4F is inserted into the inside of the recess of the arc portion 103, the worker attaches the elastic ring 104 to the first holding portion 101 and the second holding portion 102 from the front of the first holding portion 101 and the second holding portion 102. The elastic ring 104 is arranged so as to surround the first holding portion 101 and the second holding portion 102, thereby preventing the first holding portion 101 and the second holding portion 102 from being separated from each other.

[0134] The connecting member 105 is wire-shaped. The connecting member 105 may include a string, a chain, or a flexible tube. One end of the connecting member 105 is attached to the front of the socket 200. The other end of the connecting member 105 is attached to the first holding part 101 and the second holding part 102. The other end of the connecting member 105 is inserted into each of the first opening 101A and the second opening 102A. The socket holder 100 holds the socket 200 via the connecting member 105. Since the socket holder 100 holds the front of the socket 200, even if the middle part of the socket 200 breaks, the front part of the socket 200 is prevented from falling.

[0135] The socket holder 100 is disposed in front of the light assembly 18 in a state where it is attached to the hammer case 4. The arc portion 103 is formed of a plate-like member that is thin in the radial direction. This prevents the light exit surface (front surface) of the optical member 18C from being covered by the arc portion 103. Although a part of the light exit surface of the optical member 18C is covered by the arc portion 103, as shown in FIG. 3, an installation range 301 of the arc portion 103 and an installation range 302 of the light emitting element 18B do not overlap in the radial direction. The installation range 302 exists radially outward of the installation range 301. Therefore, in a state where the socket holder 100 is attached to the hammer case 4, the light assembly 18 can sufficiently illuminate the illumination target in front of the light assembly 18.

[0136] <Operation of impact tool> Next, the operation of the impact tool 1 will be described. For example, when performing a screw tightening operation on a work object, a tip tool (driver bit) used for the screw tightening operation is inserted into the tool hole 10C of the anvil 10. The tip tool inserted into the tool hole 10C is held by the tool holding mechanism 11. After the tip tool is attached to the anvil 10, the operator 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 is started, and at the same time, the light assembly 18 is turned on. When the motor 6 is started, the rotor shaft 33 of the rotor 27 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 by the spindle 8 via a pin 42P. The revolution of the planetary gear 42 causes the spindle 8 to rotate at a rotational speed lower than the rotational speed of the rotor shaft 33.

[0137] When the spindle 8 rotates while the hammer protrusion 47D and the anvil protrusion 10B 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 screw tightening operation progresses.

[0138] When a load equal to or greater than a predetermined value acts on the anvil 10 as the screw tightening operation progresses, the rotation of the anvil 10 and the hammer 47 stops. When the spindle 8 rotates while the hammer 47 is stopped rotating, the hammer 47 moves rearward. As the hammer 47 moves rearward, the contact between the hammer protrusion 47D and the anvil protrusion 10B is released. The hammer 47 that has moved rearward moves forward while rotating due to the elastic force of the coil spring 49. As the hammer 47 moves forward while rotating, the anvil 10 is struck in the rotational direction by the hammer 47. This causes the anvil 10 to rotate about the rotation axis AX with high torque. Therefore, the screw is tightened to the work object with high torque.

[0139] <Effects> As described above, in the embodiment, the impact tool 1 includes the motor 6, the spindle 8 at least a part of which is disposed forward of the motor 6 and rotated by the motor 6, the hammer 47 disposed around the spindle 8, the anvil 10 at least a part of which is disposed forward of the spindle 8 and struck in the rotational direction by the hammer 47, and an internal space 60 formed inside the spindle 8 so as to extend forward from an opening provided on the rear end surface of the spindle 8. The internal space 60 includes a first space 61 having a first inner diameter D1 connected to the opening, a second space 62 having a second inner diameter D2 provided forward of the first space 61 and smaller than the first inner diameter D1, and a third space 63 connected to the front end of the second space 62 and having a third inner diameter D3 larger than the second inner diameter D2. Lubricating oil is accommodated in the third space 63.

[0140] In the above configuration, the second space 62 having a small inner diameter is provided between the first space 61 and the third space 63. Since the second space 62 functions as a flow resistance portion for the lubricant, the lubricant contained in the third space 63 is prevented from moving to the first space 61 via the second space 62. Therefore, the lubricant contained in the third space 63 is prevented from leaking through the opening. This prevents the amount of lubricant supplied between the spindle 8 and the hammer 47 from being reduced. Therefore, wear or seizure of the spindle 8 and the hammer 47 is prevented, and the life of the impact tool 1 is prevented from being shortened.

[0141] In the embodiment, a step surface 66 facing forward is provided at the boundary between the front end of the second space 62 and the rear end of the third space 63.

[0142] In the above configuration, the step surface 66 prevents the lubricating oil contained in the third space 63 from moving to the second space 62.

[0143] In an embodiment, the third inner diameter D3 is smaller than the first inner diameter D1.

[0144] In the above configuration, the strength of the spindle 8 is prevented from decreasing.

[0145] In the embodiment, the spindle 8 includes a first supply port 81 that is provided on the outer circumferential surface of the spindle 8 and supplies the lubricating oil from the third space 63 to the space between the spindle 8 and the hammer 47 .

[0146] In the above configuration, the lubricating oil in the third space 63 is supplied between the spindle 8 and the hammer 47 through the first supply port 81 .

[0147] In the embodiment, the first flow passage 91 is provided in the spindle 8 and connects the third space 63 and the first supply port 81.

[0148] In the above configuration, when the spindle 8 rotates, the lubricating oil in the third space 63 is supplied to the first supply port 81 via the first flow passage 91 by centrifugal force.

[0149] In the embodiment, the hammer 47 has a body portion 47A and an inner cylinder portion 47C that protrudes rearward from the body portion 47A and has an inner circumferential surface that contacts the outer circumferential surface of the spindle 8. The first supply port 81 supplies lubricating oil between the outer circumferential surface of the spindle 8 and the inner circumferential surface of the inner cylinder portion 47C of the hammer 47.

[0150] In the above configuration, lubricating oil is supplied from the third space 63 between the outer peripheral surface of the spindle 8 and the inner peripheral surface of the inner cylindrical portion 47C of the hammer 47, thereby suppressing wear or seizure between the outer peripheral surface of the hammer 47 of the spindle 8 and the inner peripheral surface of the inner cylindrical portion 47C of the hammer 47.

[0151] In the embodiment, a plurality of first supply ports 81 are provided in the circumferential direction.

[0152] In the above configuration, since a plurality of first supply ports 81 are provided in the circumferential direction, the lubricating oil is evenly supplied between the outer circumferential surface of the spindle 8 and the inner circumferential surface of the inner cylindrical portion 47C of the hammer 47.

[0153] In the embodiment, the impact tool 1 includes a second supply port 82 that is provided at the front end of the spindle 8 and supplies the lubricating oil from the third space 63 to the anvil 10 .

[0154] In the above configuration, the lubricating oil is supplied between the spindle 8 and the anvil 10 from the third space 63, so that wear of the spindle 8 and the anvil 10 is suppressed.

[0155] In the embodiment, the spindle 8 has a spindle shaft portion 8A and a spindle protrusion 8F provided at the front end of the spindle shaft portion 8A. The anvil 10 has an anvil recess 10D provided at the rear end surface of the anvil 10, in which the spindle protrusion 8F is disposed. The hammer 47 is disposed around the spindle shaft portion 8A. The second supply port 82 is provided in the spindle protrusion 8F.

[0156] In the above configuration, lubricating oil is supplied from the third space 63 between the surface of the spindle protrusion 8F and the inner surface of the anvil recess 10D, thereby suppressing wear between the surface of the spindle protrusion 8F and the inner surface of the anvil recess 10D.

[0157] In the embodiment, the spindle 8 has a receiving recess 8K recessed rearward from the front end surface of the spindle protrusion 8F facing forward. The anvil 10 has a protrusion 10G protruding rearward from the bottom surface 10F of the anvil recess 10D facing rearward. The protrusion 10G is disposed inside the receiving recess 8K.

[0158] In the above configuration, the overall length of the impact tool 1 is prevented from increasing, while the contact area between the spindle protrusion 8F and the anvil recess 10D is prevented from decreasing. If the contact area between the spindle protrusion 8F and the anvil recess 10D is reduced, the stress (contact surface pressure) applied to at least one of the spindle protrusion 8F and the anvil recess 10D increases, and as a result, at least one of the spindle protrusion 8F and the anvil recess 10D may be severely worn or seized. Since the contact area between the spindle protrusion 8F and the anvil recess 10D is prevented from decreasing, the wear or seizure of the spindle protrusion 8F and the anvil recess 10D is prevented. For example, the overall length of the impact tool 1 is prevented from increasing, while the contact area between the outer peripheral surface 8L and the inner peripheral surface 10K is prevented from decreasing. Therefore, the life of the impact tool 1 is prevented from being shortened. The overall length of the impact tool 1 refers to the distance in the front-rear direction between the rear end of the rear cover 3 and the front end of the anvil 10.

[0159] In this embodiment, the second supply port 82 is provided in the bottom surface of the accommodating recess 8K facing forward.

[0160] In the above-described configuration, the lubricating oil is evenly supplied to the surface of the spindle protrusion 8F and the inner surface of the anvil recess 10D.

[0161] In this embodiment, the protrusion 10G has a tapered shape in which the outer diameter decreases toward the rear.

[0162] In the above-described configuration, the protrusion 10G is provided to match the shape of the rear end of the tool hole 10C provided in the anvil 10.

[0163] In the embodiment, the rear end portion (rear end surface 10H) of the protrusion 10G is disposed forward of the rear end surface 10L of the anvil 10.

[0164] In the above configuration, since the protrusion 10G does not protrude rearward from the rear end surface 10L of the anvil 10, the depth of the receiving recess 8K does not need to be excessively deep.

[0165] In the embodiment, the impact tool 1 includes a hammer case 4 that supports an anvil 10 via an anvil bearing 46. The anvil 10 has a tool hole 10C into which a rear portion of a socket 200 is inserted. A socket holder 100 that holds the socket 200 via a connecting member 105 is attached to the hammer case 4. The socket holder 100 has an arc portion 103 that is hooked onto a hook portion 4F provided on the hammer case 4, a first holding portion 101 provided at one end of the arc portion 103, a second holding portion 102 provided at the other end of the arc portion 103, and an elastic ring 104 that fixes the first holding portion 101 and the second holding portion 102. The connecting member 105 is connected to each of the first holding portion 101 and the second holding portion 102.

[0166] In the above configuration, even if the middle portion of socket 200 is broken, the front portion of socket 200 is prevented from falling because the front portion of socket 200 is held by socket holder 100. In addition, since first holding portion 101 and second holding portion 102 are fixed by elastic ring 104, the structure of socket holder 100 is simplified and the cost of socket holder 100 is reduced.

[0167] In the embodiment, the first holding portion 101 is provided so as to protrude forward from one end of the arc portion 103. The second holding portion 102 is provided so as to protrude forward from the other end of the arc portion 103.

[0168] In the above configuration, the worker can attach the elastic ring 104 around the first holding portion 101 and the second holding portion 102 from the front of the first holding portion 101 and the second holding portion 102.

[0169] In the embodiment, the first holding portion 101 has a first opening 101 A. The second holding portion 102 has a second opening 102 A. The connecting member 105 is inserted into each of the first opening 101A and the second opening 102A.

[0170] In the above configuration, socket holder 100 and connecting member 105 are connected together by inserting connecting member 105 into first opening 101A and second opening 102A, respectively.

[0171] [Other embodiments] In the above-described embodiment, the impact tool 1 is an impact driver. The impact tool 1 may be an impact wrench.

[0172] In the above-described embodiment, the power source of 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]

[0173] Reference Signs List 1...Impact tool, 2...Housing, 2L...Left housing, 2R...Right housing, 2S...Screw, 3...Rear cover, 3S...Screw, 4...Hammer case, 4A...Large cylinder portion, 4B...Small cylinder portion, 4C...Connection portion, 4F...Hook portion, 6...Motor, 7...Reduction mechanism, 8...Spindle, 8A...Spindle shaft portion, 8B...First flange portion, 8C...Second flange portion, 8D...Connection portion, 8F...Spindle protrusion portion, 8K...Accommodation recess portion, 8J...Front end surface, 8L...Outer peripheral surface, 8M...Front end surface, 8G...Spindle groove, 8S...Outer peripheral surface, 9...Impact mechanism, 10...Anvil, 10A...Anvil shaft portion, 10B ...anvil protrusion, 10C...tool hole, 10D...anvil recess, 10F...bottom surface, 10G...protrusion, 10L...rear end surface, 10H...rear end surface, 10J...outer surface, 10K...inner surface, 11...tool holding mechanism, 12...fan, 12A...bush, 13...battery mounting section, 14...trigger lever, 15...forward / reverse switching lever, 18...light assembly, 18A...circuit board, 18B...light emitting element, 18C...optical member, 19...intake port, 20...exhaust port, 21...motor housing, 22...grip section, 23...battery holding section, 24...bearing box, 24A...rear annular section, 24B...front annular section , 24C...connection part, 25...battery pack, 26...stator, 27...rotor, 28...stator core, 29...rear insulator, 30...front insulator, 30S...screw, 31...coil, 32...rotor core, 33...rotor shaft, 34A...rotor magnet, 34B...sensor magnet, 35...sensor board, 36...fusing terminal, 37...rear rotor bearing, 38...front rotor bearing, 41...pinion gear, 42...planetary gear, 42P...pin, 43...internal gear, 44...spindle bearing, 45...O-ring, 46...anvil bearing, 47...Hammer, 47A...Body portion, 47B...Outer cylinder portion, 47C...Inner cylinder portion, 47D...Hammer protrusion portion, 47E...Recess, 47G...Hammer groove, 47S...Inner peripheral surface, 48...Ball, 49...Coil spring, 50...Washer, 51...Hammer case cover, 52...Light cover, 54...Ball, 56...Washer, 57...Support member, 59...Opening, 60...Internal space, 61...First space, 62...Second space, 63...Third space, 64...Fourth space, 65...Fifth space, 66...Step surface, 71...Ball, 72...Leaf spring, 73...Sleeve, 74...Coil spring, 75...Positioning member,76...support recess, 81...first supply port, 81A...first supply port, 81B...first supply port, 82...second supply port, 91...first flow path, 100...socket holder, 101...first holding portion, 101A...first opening, 102...second holding portion, 102A...second opening, 103...arc portion, 104...elastic ring, 105...connecting member, 200...socket, AX...rotating shaft, D1...first inner diameter, D2...second inner diameter, D3...third inner diameter, D4...fourth inner diameter, D5...fifth inner diameter.

Claims

1. A motor, a spindle at least part of which is disposed in front of the motor and is rotated by the motor, a hammer disposed around the spindle, an anvil at least part of which is disposed in front of the spindle and is struck in the rotational direction by the hammer, and an internal space formed inside the spindle so as to extend forward from an opening provided at the rear end surface of the spindle, wherein the internal space includes a first space having a first inner diameter connected to the opening, a second space provided in front of the first space and having a second inner diameter smaller than the first inner diameter, and a third space connected to the front end portion of the second space and having a third inner diameter larger than the second inner diameter, wherein lubricating oil is accommodated in the third space, an impact tool.

2. A stepped surface facing forward is provided at the boundary between the front end portion of the second space and the rear end portion of the third space, The impact tool according to claim 1.

3. The third inner diameter is smaller than the first inner diameter, The impact tool according to claim 1.

4. The impact tool according to claim 1, further comprising a first supply port provided on the outer peripheral surface of the spindle for supplying lubricating oil from the third space between the hammer. The impact tool according to claim 1.

5. The impact tool according to claim 4, further comprising a first flow path provided in the spindle for connecting the third space and the first supply port. The impact tool according to claim 4.

6. The hammer has a body portion and an inner cylinder portion that protrudes rearward from the body portion and has an inner peripheral surface that contacts the outer peripheral surface of the spindle, The first supply port supplies the lubricating oil between the outer peripheral surface of the spindle and the inner peripheral surface of the inner cylinder portion. The impact tool according to claim 4.

7. A plurality of the first supply ports are provided in the circumferential direction, The impact tool according to claim 4.

8. The impact tool according to claim 1, further comprising a second supply port provided at the front end portion of the spindle for supplying lubricating oil from the third space between the anvil. The impact tool according to claim 1.

9. The spindle has a spindle shaft portion and a spindle convex portion that protrudes forward from the front end portion of the spindle shaft portion, The anvil has an anvil concave portion provided on the rear end surface of the anvil and in which the spindle convex portion is disposed, The hammer is disposed around the spindle shaft portion, The second supply port is provided in the spindle convex portion, The impact tool according to claim 8.

10. The spindle has a receiving recess that is recessed rearward from the front end face of the spindle convex portion facing forward. The anvil has a protrusion that protrudes rearward from the bottom surface of the anvil recess facing rearward. The protrusion is disposed inside the receiving recess. The impact tool according to claim 9.

11. The second supply port is provided on the bottom surface of the receiving recess facing forward. The impact tool according to claim 10.

12. A motor, A spindle at least a part of which is disposed forward of the motor and is rotated by the motor, A hammer disposed around the spindle, An anvil at least a part of which is disposed forward of the spindle and is struck in the rotational direction by the hammer, The spindle has a spindle shaft portion, a spindle convex portion that protrudes forward from the front end portion of the spindle shaft portion, and a receiving recess that is recessed rearward from the front end face of the spindle convex portion facing forward. The anvil has an anvil recess provided on the rear end face of the anvil and in which the spindle convex portion is disposed, and a protrusion that protrudes rearward from the bottom surface of the anvil recess facing rearward. The hammer is disposed around the spindle shaft portion. The protrusion is disposed inside the receiving recess. An impact tool.

13. The protrusion is tapered such that the outer diameter decreases toward the rear. The impact tool according to claim 10.

14. The rear end face of the protrusion is disposed forward of the rear end face of the anvil. The impact tool according to claim 10.

15. Comprising a hammer case that supports the anvil via an anvil bearing, The anvil has a tool hole into which the rear portion of the socket is inserted. A socket holder that holds the socket via a connecting member is attached to the hammer case. The socket holder has an arc portion that is hung on a hook portion provided on the hammer case, a first holding portion provided at one end of the arc portion, a second holding portion provided at the other end of the arc portion, and an elastic ring that fixes the first holding portion and the second holding portion. The connecting member is connected to each of the first holding portion and the second holding portion. The impact tool according to claim 1.

16. A motor, A spindle at least a part of which is disposed forward of the motor and is rotated by the motor, A hammer disposed around the spindle, An anvil at least partially disposed forward of the spindle and struck in the rotational direction by the hammer, A hammer case that supports the anvil via an anvil bearing, and The anvil has a tool hole into which the rear portion of the socket is inserted, A socket holder that holds the socket via a connecting member is attached to the hammer case, The socket holder has an arc portion that is hung on a hook portion provided on the hammer case, a first holding portion provided at one end of the arc portion, a second holding portion provided at the other end of the arc portion, and an elastic ring that fixes the first holding portion and the second holding portion, The connecting member is connected to each of the first holding portion and the second holding portion, An impact tool.

17. The first holding portion is provided so as to protrude forward from one end of the arc portion, The second holding portion is provided so as to protrude forward from the other end of the arc portion, The impact tool according to claim 15.

18. The first holding portion has a first opening, The second holding portion has a second opening, The connecting member is inserted into each of the first opening and the second opening, The impact tool according to claim 15.

Images