Impact tools

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 such as that 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 accommodated in the internal space of the spindle. The lubricating oil is supplied from the internal space of the spindle to between the spindle and the hammer. [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 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 partially disposed forward of the motor and rotated by the motor, a hammer disposed around the spindle, an anvil at least partially disposed forward of the spindle and struck by the hammer in the rotational direction, and an internal space formed inside the spindle and extending forward from an opening provided in a rear end face 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 and disposed forward of the first space, and a third space having a third inner diameter larger than the second inner diameter and connected to a front end of the second space. Lubricant may be stored in the third space. [Effects of the Invention]

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

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

[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 and extending forward from an opening provided in a rear end face 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 and disposed forward of the first space, and a third space having a third inner diameter larger than the second inner diameter and connected to a front end of the second space. 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. Because 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 a reduction in the amount of lubricating oil supplied between the spindle and the hammer. Therefore, wear or seizure of the spindle and the hammer is prevented, and a shortened lifespan of the impact tool is prevented.

[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 stepped surface prevents the lubricating oil contained in the third space from moving 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, the reduction in strength of the spindle is suppressed.

[0015] In one or more embodiments, the spindle may include a first supply port provided on the outer peripheral surface thereof 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 path 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 cylindrical portion protruding rearward from the body portion and having an inner circumferential surface that contacts the 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 cylindrical portion of the hammer.

[0020] In the above configuration, lubricating oil is supplied from the third space between the outer surface of the spindle and the inner surface of the inner cylindrical portion of the hammer, thereby suppressing wear or seizure between the outer surface of the hammer of the spindle and the inner 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, a plurality of first supply ports are provided in the circumferential direction, so that 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 the 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 from the third space between the spindle and the anvil, 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 of the spindle shaft portion. The anvil may have an anvil recess portion 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 rearward from the front end surface of the forward-facing spindle protrusion. The anvil may have a protrusion protruding rearward from the bottom surface of the rear-facing anvil recess. The protrusion may be disposed inside the receiving recess.

[0028] The above configuration prevents the overall length of the impact tool from increasing, while also preventing the contact area between the spindle protrusion and the anvil recess from decreasing. If the contact area between the spindle protrusion and the anvil recess becomes smaller, the stress (contact surface pressure) applied to at least one of the spindle protrusion and the anvil recess increases, which can result in severe wear or seizure of at least one of the spindle protrusion and the anvil recess. Since the contact area between the spindle protrusion and the anvil recess is prevented from decreasing, wear or seizure of the spindle protrusion and the anvil recess is prevented. This prevents the life of the impact tool from being shortened.

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

[0030] In the above-described configuration, the lubricating oil is evenly supplied to the surface of the spindle convex portion and the inner surface of the anvil concave portion.

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

[0032] In the above 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 located forward of the rear face of the anvil.

[0034] In the above-described configuration, the protrusion does not protrude from the rear end surface of the anvil, so the depth of the receiving recess does not need to be excessively large.

[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 secures the first holding portion and the second holding portion together. The connecting member may be connected to each of the first holding portion and the second holding portion.

[0036] In the above configuration, the socket holder holds the front portion of the socket, preventing the front portion of the socket from falling even if the middle portion of the socket breaks. In addition, the elastic ring secures the first and second holding portions together, simplifying the structure of the socket holder and reducing the cost of the socket holder.

[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 opening and the second opening.

[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 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.

[0043] 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.

[0044] <Impact tool> 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, and 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 rotation switch 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 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.

[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 and extends downward from the motor housing portion 21. The trigger lever 14 is provided on the 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 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.

[0051] The rear cover 3 is arranged to cover the opening at the rear end of the motor accommodating section 21. The rear cover 3 is arranged behind the motor accommodating section 21. The rear cover 3 accommodates at least a portion of the fan 12. The fan 12 is arranged inside the rear cover 3. The rear cover 3 holds the 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 section 21 with two screws 3S.

[0052] The motor accommodating section 21 has an air intake port 19. The rear cover 3 has an air exhaust port 20. Air from the external space of the housing 2 flows into the internal space of the housing 2 through the air intake port 19. Air from 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 portion of the reduction mechanism 7, the spindle 8, the striking mechanism 9, and at least a portion of the anvil 10. 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 includes a large cylinder portion 4A, a small cylinder portion 4B, and a connecting portion 4C. The small cylinder portion 4B is positioned forward of the large cylinder portion 4A. The front end of the large cylinder portion 4A and the rear end 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 portion 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 threaded portion or by fitting (loose 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 cylindrical portion 4A. The bearing box 24 and the hammer case 4 may be fixed together by engaging the screw threads of the front annular portion 24B with the screw grooves of the large cylindrical portion 4A. The bearing box 24 and the hammer case 4 may be fixed together by fitting the front annular portion 24B into the large cylindrical portion 4A. The front rotor bearing 38 is disposed radially inside the rear annular portion 24A. The spindle bearing 44 is disposed radially inside the connecting portion 24C.

[0055] The hammer case 4 is sandwiched between the left housing 2L and the right housing 2R. The rear part of the hammer case 4 is housed in the motor housing portion 21. The hammer case 4 is connected to the front part of the motor housing portion 21. The bearing box 24 is fixed to both 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 prevents the hammer case 4 from coming into contact with 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 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.

[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 part of the stator core 28. The front insulator 30 is fixed to the front part of the stator core 28. The rear insulator 29 is arranged so as to cover part of the surface of the teeth. The front 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 rear insulator 29 and the front insulator 30. Multiple 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 and 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. A rear portion of the rotor shaft 33 protrudes rearward from the rear end surface of the rotor core 32. A front portion of the rotor shaft 33 protrudes forward from the front end surface of the rotor core 32.

[0064] The rotor magnet 34A is fixed to the rotor core 32. In this embodiment, the rotor magnet 34A is arranged around the rotor core 32. The sensor magnet 34B is fixed to the rotor core 32. In this embodiment, the sensor magnet 34B is arranged 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 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 connects the rotor shaft 33 and the spindle 8. The gears of the reduction mechanism 7 are driven by the rotor 27. The reduction mechanism 7 transmits the rotation of the rotor 27 to the spindle 8. The reduction mechanism 7 rotates the spindle 8 at a rotational speed lower than the rotational speed of the rotor shaft 33. The reduction mechanism 7 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 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.

[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 is rotated 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 coincides with the rotation axis AX. 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 located 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 to 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 located 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 the 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 a motor 6. The rotational force of the motor 6 is transmitted to the striking mechanism 9 via a reduction mechanism 7 and a 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 cylindrical 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 cylindrical portion 47B, an inner cylindrical 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 cylindrical portion 47B and the inner cylindrical portion 47C each protrude rearward from the body portion 47A. The outer cylindrical portion 47B is disposed radially outward from the inner cylindrical portion 47C. A recess 47E is defined by the rear surface of the body portion 47A, the inner peripheral surface of the outer cylindrical portion 47B, and the outer peripheral surface of the inner cylindrical portion 47C. The recess 47E is recessed forward from the rear end 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 cylindrical portion 47C. The inner cylindrical portion 47C has an inner peripheral surface 47S that contacts the outer peripheral 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 is supported by a washer 50. The coil spring 49 constantly generates an elastic force that moves the hammer 47 forward.

[0082] The balls 48 are made of a metal such as steel. The balls 48 are 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 balls 48 are 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 balls 48 are 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 cylindrical 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 balls 48 can roll inside the spindle groove 8G and the hammer groove 47G. The hammer 47 can move along with the balls 48. The spindle 8 and the hammer 47 can move relative to each other in the axial and rotational directions 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-to-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 bit is inserted into the tool hole 10C. The tool bit is attached to the anvil 10. The anvil recess 10D is 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 an 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 cylindrical portion 4B of the hammer case 4. The anvil bearing 46 is held by the small cylindrical 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 this embodiment, two anvil bearings 46 are disposed in the front-to-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 connecting 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 cylindrical 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 behind. The washer 56 is arranged in a groove provided on the inner surface of the large cylindrical portion 4A.

[0089] The hammer protrusion 47D can come into contact with the anvil protrusion 10B. When the motor 6 is driven 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.

[0090] The anvil 10 is struck in the rotational direction by the hammer 47. For example, during a screw tightening operation, if the load acting on the anvil 10 becomes too high, a situation may occur in which the anvil 10 cannot be rotated by the load of the coil spring 49 alone. When the load of the coil spring 49 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 movable relative to each other in the axial and circumferential directions via the ball 48. Even after 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 ball 48 moves rearward while being guided by 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 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. After moving backward, the hammer 47 moves forward due to the elastic force of the coil spring 49. When the hammer 47 moves forward, it receives a rotational force from the ball 48. That is, the hammer 47 moves forward while rotating. When the hammer 47 moves forward while rotating, it 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 portion 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 includes 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 this embodiment, two support recesses 76 are formed in the anvil shaft portion 10A.

[0095] The balls 71 are movably supported on the anvil 10. The balls 71 are arranged in the support recesses 76. The balls 71 are arranged one per 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 portion 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 tool bit is released from the engagement position.

[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 movable in the axial direction around the anvil shaft portion 10A. The sleeve 73 can prevent the ball 71, which is disposed in the engagement position, from escaping from the engagement position. By moving the sleeve 73 in the axial direction, the ball 71 can be changed to a state in which it can be moved from the engagement position to the release position.

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

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

[0101] When the sleeve 73 is moved to the permissible position, the ball 71, which is positioned at the engagement position, is allowed to move radially outward. When the sleeve 73 is moved to the permissible position, the ball 71 is allowed to move from the engagement position to the release position. In other words, when the sleeve 73 is placed at the permissible position, the ball 71, which is positioned at the engagement position, is allowed to move out of the engagement position. When the sleeve 73 is placed at the permissible position, the state in which the tool bit is fixed by the ball 71 can be released.

[0102] The coil spring 74 generates an elastic force that moves 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 that moves 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 where it can face 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, thereby being positioned at the blocking position.

[0104] The fan 12 is disposed rearward of the stator 26 of the motor 6. The fan 12 generates an airflow for cooling the motor 6. The fan 12 is fixed to at least a portion of the rotor 27. The fan 12 is fixed to the rear of the rotor shaft 33 via a bushing 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. As the rotor shaft 33 rotates, the fan 12 rotates together with the rotor shaft 33. 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 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 into the external space of the housing 2 through the air exhaust 20.

[0105] The battery attachment section 13 is disposed below the battery holding section 23. 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 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.

[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 area around the anvil 10 with the illumination light. The light assembly 18 illuminates the area in front of the anvil 10 with the illumination light. The light assembly 18 also illuminates the tool insert attached to the anvil 10 and the area around the tool insert with the illumination light. In the embodiment, the light assembly 18 is disposed around the small cylindrical 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 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 coming into contact with objects around the light assembly 18. The light cover 52 is disposed around the optical member 18C.

[0110] <Spindle internal space> Figure 5 is an enlarged view of a portion of Figure 3. As shown in Figures 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. The front end of the pinion gear 41 is inserted into the rear end of the first space 61 through the 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 coincides 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 [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 lubricating oil from the first space 61 between the spindle 8 and the hammer 47. In this embodiment, the first supply port 81 supplies 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 path 91 formed inside the spindle shaft portion 8A. The first flow path 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. Due to the centrifugal force of the spindle 8, the lubricating oil contained in the third space 63 flows through the first flow path 91 toward the first supply port 81. The lubricating oil supplied from the third space 63 to the first supply port 81 via the first flow path 91 is supplied between the outer peripheral surface 8S of the spindle shaft portion 8A and the inner peripheral 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 lubricating oil between the sliding surfaces, that is, the outer peripheral surface 8S and the inner peripheral surface 47S, 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 this embodiment, the first supply ports 81 include a first supply port 81A and a first supply port 81B that is provided at a different position from the first supply port 81A in the circumferential direction. In the front-rear direction, the positions of the first supply ports 81A and the first supply ports 81B are substantially the same. In the circumferential direction, the first supply ports 81A and the first supply ports 81B are disposed at positions that are 180 degrees apart.

[0121] The relative angle between the first supply ports 81A and 81B in the circumferential direction is an example. The number of first supply ports 81 does not have to be two, and may be one, or 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 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 this embodiment, the second supply port 82 is provided in the spindle protrusion 8F. The second supply port 82 supplies 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 via 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 a storage recess 8K recessed rearward from the 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 the bottom surface 10F of the anvil recess 10D. The bottom surface 10F faces rearward. The protrusion 10G is disposed inside the storage recess 8K. The second supply port 82 is provided in the bottom surface of the storage recess 8K facing forward.

[0125] The outer diameter of the protrusion 10G decreases toward the rear. The protrusion 10G is tapered so that the outer diameter decreases toward the rear. The inner diameter of the accommodating recess 8K decreases toward the rear. The accommodating recess 8K is tapered so that the inner diameter decreases 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 this 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. The outer peripheral surface 8L of the spindle protrusion 8F and the inner peripheral surface 10K of the anvil recess 10D are in contact. The front end surface 8J of the spindle protrusion 8F and the bottom surface 10F of the anvil recess 10D face each other across 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 across 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 spaced apart.

[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 front perspective view showing the upper part of the impact tool 1 according to the embodiment. Fig. 8 is an exploded front perspective view showing the upper part of the impact tool 1 according to the embodiment. 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 a 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.

[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 secures 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 cylindrical portion 4B of the hammer case 4. The hook portion 4F protrudes radially outward from the outer peripheral surface of the small cylindrical portion 4B. The hook portion 4F is ring-shaped. A recess is provided on the inner peripheral 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 attaching the socket holder 100 to the hammer case 4, the worker arranges the arc portion 103 around the small cylindrical portion 4B in a state in which the arc portion 103 is elastically deformed so that the diameter of the arc portion 103 expands. After the arc portion 103 is arranged around the small cylindrical 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 separating from each other.

[0134] The connecting member 105 is wire-like. 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 portion 101 and the second holding portion 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 portion of the socket 200 breaks, the front portion of the socket 200 is prevented from falling.

[0135] When the socket holder 100 is attached to the hammer case 4, it is disposed in front of the light assembly 18. 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 portion 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 is located radially outward of the installation range 301. Therefore, when the socket holder 100 is attached to the hammer case 4, the light assembly 18 can sufficiently illuminate an illumination target that is 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 screwdriver operation on a workpiece, a tool bit (driver bit) to be used for the screwdriver operation is inserted into the tool hole 10C of the anvil 10. The tool bit inserted into the tool hole 10C is held by the tool holding mechanism 11. After the tool bit is attached to the anvil 10, the operator 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 is started, and the light assembly 18 is simultaneously illuminated. 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, meshed with the internal teeth of the internal gear 43, revolves around the pinion gear 41 while rotating on its axis. 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] As the screw tightening operation progresses, if a load greater than a predetermined value acts on the anvil 10, the rotation of the anvil 10 and the hammer 47 stops. When the spindle 8 rotates while the hammer 47 is stopped, the hammer 47 moves rearward. As the hammer 47 moves rearward, contact between the hammer protrusion 47D and the anvil protrusion 10B is released. The hammer 47, which 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. As a result, the anvil 10 rotates around the rotation axis AX with high torque. Therefore, the screw is tightened into the workpiece 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 portion 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 portion 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 and extending forward from an opening provided in 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 disposed 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 stored in the third space 63.

[0140] In the above configuration, the second space 62, which has a small inner diameter, is provided between the first space 61 and the third space 63. The second space 62 functions as a flow resistance portion for the lubricating oil, so that the lubricating oil contained in the third space 63 is prevented from moving to the first space 61 via the second space 62. This prevents the lubricating oil contained in the third space 63 from leaking through the opening. This prevents the amount of lubricating oil supplied between the spindle 8 and the hammer 47 from becoming reduced. This prevents wear or seizure of the spindle 8 and the hammer 47, and prevents the life of the impact tool 1 from becoming shorter.

[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 into the second space 62.

[0143] In the 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 being reduced.

[0145] In the embodiment, the spindle 8 is provided with a first supply port 81 that is provided on the outer peripheral surface of the spindle 8 and that 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 spindle 8 is provided with a first flow path 91 that 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 path 91 by centrifugal force.

[0149] In the embodiment, the hammer 47 has a body portion 47A and an inner cylindrical 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 cylindrical 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 this embodiment, a plurality of first supply ports 81 are provided in the circumferential direction.

[0152] In the above configuration, a plurality of first supply ports 81 are provided in the circumferential direction, so that 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 that supplies the lubricating oil from the third space 63 to the anvil 10 .

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

[0155] In this 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 is provided at the rear end surface of the anvil 10 and has an anvil recess 10D 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 this 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] The above configuration prevents the overall length of the impact tool 1 from increasing while preventing the contact area between the spindle protrusion 8F and the anvil recess 10D from decreasing. If the contact area between the spindle protrusion 8F and the anvil recess 10D decreases, the stress (contact surface pressure) applied to at least one of the spindle protrusion 8F and the anvil recess 10D increases, potentially resulting in severe wear or seizure of at least one of the spindle protrusion 8F and the anvil recess 10D. Since the contact area between the spindle protrusion 8F and the anvil recess 10D is prevented from decreasing, 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 preventing the contact area between the outer peripheral surface 8L and the inner peripheral surface 10K from decreasing. Therefore, the life of the impact tool 1 is prevented from shortening. The overall length of the impact tool 1 refers to the distance between the rear end of the rear cover 3 and the front end of the anvil 10 in the front-to-rear direction.

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

[0160] In the above 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 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, the protrusion 10G does not protrude rearward from the rear end surface 10L of the anvil 10, so the depth of the accommodation recess 8K does not need to be excessively deep.

[0165] In this 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 the rear of a socket 200 is inserted. A socket holder 100 that holds the socket 200 is attached to the hammer case 4 via a connecting member 105. The socket holder 100 includes 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 secures the first holding portion 101 and the second holding portion 102 together. 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, the front portion of socket 200 is held by socket holder 100, which prevents the front portion of socket 200 from falling even if the middle portion of socket 200 breaks. Furthermore, because first holding portion 101 and second holding portion 102 are fixed together 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 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]

[0173] 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...bushing, 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 section, 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...Recessed portion, 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 axis, 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 a portion of which is disposed forward of the motor and which is 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 which is struck in a rotational direction by the hammer; 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 includes 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 and disposed forward of the first space, and a third space having a third inner diameter larger than the second inner diameter and connected to a front end of the second space, A lubricant is contained in the third space. Impact tool.

2. a step surface facing forward is provided at the boundary between the front end of the second space and the rear end 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. a first supply port provided on an outer peripheral surface of the spindle for supplying lubricating oil from the third space to the space between the spindle and the hammer; The impact tool according to claim 1 .

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

6. the hammer has a body portion and an inner cylindrical portion that protrudes rearward from the body portion and has an inner peripheral surface that contacts an outer peripheral surface of the spindle, the first supply port supplies the lubricating oil between an outer circumferential surface of the spindle and an inner circumferential surface of the inner cylindrical portion.

5. The impact tool according to claim 4.

7. The first supply port is provided in plurality in the circumferential direction.

5. The impact tool according to claim 4.

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

9. the spindle has a spindle shaft portion and a spindle protrusion portion protruding forward from a front end portion of the spindle shaft portion, the anvil has an anvil recess provided on a rear end surface of the anvil and in which the spindle protrusion is disposed, The hammer is disposed around the spindle shaft portion, The second supply port is provided in the spindle protrusion.

9. The impact tool according to claim 8.

10. the spindle has an accommodating recess recessed rearward from a front end surface of the spindle protrusion facing forward, The anvil has a protrusion that protrudes rearward from a bottom surface of the anvil recess that faces rearward, The protrusion is disposed inside the accommodating recess.

10. The impact tool according to claim 9.

11. The second supply port is provided on a bottom surface of the accommodating recess facing forward.

11. An impact tool according to claim 10.

12. A motor; a spindle at least a portion of which is disposed forward of the motor and which is 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 which is struck in the rotational direction by the hammer; the spindle has a spindle shaft portion, a spindle protrusion portion protruding forward from a front end portion of the spindle shaft portion, and an accommodating recess portion recessed rearward from a front end surface of the spindle protrusion portion facing forward, the anvil has an anvil recess provided on a rear end surface of the anvil and in which the spindle protrusion is disposed, and a protrusion protruding rearward from a bottom surface of the anvil recess facing rearward, The hammer is disposed around the spindle shaft portion, The protrusion is disposed inside the accommodating recess. Impact tool.

13. The protrusion has a tapered shape in which the outer diameter decreases toward the rear.

11. An impact tool according to claim 10.

14. The rear end surface of the protrusion is disposed forward of the rear end surface of the anvil.

11. An impact tool according to claim 10.

15. a hammer case supporting the anvil via an anvil bearing; The anvil has a tool hole into which a 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 arcuate portion that is hooked onto a hook portion provided on the hammer case, a first holding portion provided at one end of the arcuate portion, a second holding portion provided at the other end of the arcuate portion, and an elastic ring that fixes the first holding portion and the second holding portion together, 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 portion of which is disposed forward of the motor and which is 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 which is struck in a rotational direction by the hammer; a hammer case that supports the anvil via an anvil bearing, The anvil has a tool hole into which a 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 arcuate portion that is hooked onto a hook portion provided on the hammer case, a first holding portion provided at one end of the arcuate portion, a second holding portion provided at the other end of the arcuate portion, and an elastic ring that fixes the first holding portion and the second holding portion together, The connecting member is connected to each of the first holding portion and the second holding portion. 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.

16. An 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.

16. An impact tool according to claim 15.

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