Power tool

Abstract

To suppress a shadow of a work object.SOLUTION: A power tool includes: a motor; an output shaft rotated by the rotational force of the motor; a chip-on-board light-emitting diode disposed around the output shaft; and a white translucent optical member that has a light refracting portion that refracts light emitted from the chip-on-board light-emitting diode. On at least one cross section that is parallel to a rotation axis of the output shaft and passes through the rotation axis, a shape of the light refracting portion is symmetrical with respect to the rotation axis.SELECTED DRAWING: Figure 21

Description

[Technical Field]

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

[0002] BACKGROUND ART In the technical field related to power tools, a lighting system for a power tool, such as that disclosed in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2016 / 0354889 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the lighting system for a power tool includes chip-on-board light-emitting diodes (COB LEDs). The chip-on-board light-emitting diodes have a high light output and can brightly illuminate a work object. However, the chip-on-board light-emitting diodes generate a large amount of heat, which may cause the temperature of the chip-on-board light-emitting diode to rise excessively. If the temperature of the chip-on-board light-emitting diode rises excessively, the chip-on-board light-emitting diode may deteriorate or its lifespan may be shortened. Furthermore, if a shadow is cast on the work object, it may be difficult for the worker to see the work object.

[0005] The technology disclosed in this specification aims to prevent excessive temperature rise in chip-on-board light-emitting diodes and to prevent shadows from being cast on the work object. [Means for solving the problem]

[0006] This specification discloses a power tool, which may include a motor, an output shaft that rotates by torque of the motor, a chip-on-board light-emitting diode disposed around the output shaft, and a heat dissipation device that dissipates heat from the chip-on-board light-emitting diode.

[0007] The power tool may also include a motor, an output shaft that rotates by the rotational force of the motor, a chip-on-board light-emitting diode arranged around the output shaft, and a white translucent optical member having a light-refracting portion that refracts light emitted from the chip-on-board light-emitting diode. In at least one cross section that is parallel to and passes through the rotation axis of the output shaft, the shape of the light-refracting portion may be line-symmetrical with respect to the rotation axis. [Effects of the Invention]

[0008] According to the above configuration, an excessive temperature rise of the chip-on-board light-emitting diode is suppressed, and also, according to the above configuration, the casting of a shadow on the work object is suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front perspective view showing a power tool according to a first embodiment. [Figure 2] FIG. 2 is a side view showing the power tool according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing the power tool according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the upper part of the power tool according to the first embodiment. [Figure 5] FIG. 5 is a diagram schematically showing the chip-on-board light-emitting diode according to the first embodiment. [Figure 6] FIG. 6 is a perspective view showing the light unit according to the first embodiment, as viewed from the front. [Figure 7] FIG. 7 is a perspective view showing the light unit according to the first embodiment, seen from behind. [Figure 8]FIG. 8 is an exploded perspective view from the front showing the light unit according to the first embodiment. [Figure 9] FIG. 9 is an exploded perspective view showing the light unit according to the first embodiment, as seen from behind. [Figure 10] FIG. 10 is a rear view of the light cover according to the first embodiment. [Figure 11] FIG. 11 is a view of the upper part of the power tool according to the first embodiment as seen from the front. [Figure 12] FIG. 12 is an exploded perspective view of the upper portion of the power tool according to the first embodiment, as viewed from the front. [Figure 13] FIG. 13 is an exploded perspective view of the upper portion of the power tool according to the first embodiment, seen from the rear. [Figure 14] FIG. 14 is a cross-sectional view showing a part of the power tool according to the first embodiment. [Figure 15] FIG. 15 is a cross-sectional view showing a part of a power tool according to the second embodiment. [Figure 16] FIG. 16 is a cross-sectional view showing a part of a power tool according to a third embodiment. [Figure 17] FIG. 17 is an exploded perspective view of the upper part of the power tool according to the third embodiment, as viewed from the front. [Figure 18] FIG. 18 is a front perspective view showing a power tool according to a fourth embodiment. [Figure 19] FIG. 19 is a cross-sectional view showing a power tool according to a fourth embodiment. [Figure 20] FIG. 20 is a view of the light unit according to the fifth embodiment as seen from the front. [Figure 21] FIG. 21 is a vertical cross-sectional view showing a light unit according to the fifth embodiment. [Figure 22] FIG. 22 is a cross-sectional view showing the light unit according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] In one or more embodiments, a power tool may include a motor, an output shaft that rotates by torque of the motor, a chip-on-board light-emitting diode arranged around the output shaft, and a white translucent optical member having a light-refracting portion that refracts light emitted from the chip-on-board light-emitting diode. In at least one cross section that is parallel to and passes through a rotation axis of the output shaft, the shape of the light-refracting portion may be axisymmetric with respect to the rotation axis.

[0011] In the above configuration, the chip-on-board light-emitting diodes are arranged in a ring shape around the output shaft, and the light refracting section is line-symmetric, so that light is emitted in a ring shape from the light refracting section, which reduces the shadow on the work object.

[0012] In one or more embodiments, the light refracting portion may have an incident surface onto which light emitted from the chip-on-board light emitting diode is incident and an exit surface from which light transmitted through the light refracting portion is exited, and each of the incident surface and the exit surface may be symmetrical about the rotation axis.

[0013] In the above configuration, the entrance surface and the exit surface are both ring-shaped and line-symmetric, so that light is emitted in a ring shape from the optical element. In other words, the entire optical element does not need to be line-symmetric; it is sufficient that the entrance surface and the exit surface are line-symmetric.

[0014] In one or more embodiments, the entrance surface may be angled radially outwardly and rearward, and the exit surface may be perpendicular to an axis parallel to the axis of rotation.

[0015] In the above configuration, the light spreads appropriately from the light transmitting portion, brightly illuminating the work object.

[0016] In one or more embodiments, the shape of the light refracting portion may be symmetrical with respect to the rotation axis in all cross sections passing through the rotation axis.

[0017] In the above configuration, the shape of the light refracting portion is line-symmetrical with respect to the rotation axis in all cross sections parallel to the rotation axis, so that light is emitted in a ring shape from the light refracting portion.The chip-on-board light-emitting diodes brightly illuminate the work object.

[0018] In one or more embodiments, a power tool may include a motor, an output shaft that rotates due to the rotational force of the motor, a chip-on-board light-emitting diode disposed around the output shaft, and a heat dissipation device that dissipates heat from the chip-on-board light-emitting diode.

[0019] In the above configuration, the heat generated by the chip-on-board light-emitting diode is dissipated by the heat dissipation device, thereby preventing the chip-on-board light-emitting diode from excessively increasing in temperature.

[0020] In one or more embodiments, the heat dissipation device may include a heat dissipation member to which heat from the chip-on-board light emitting diode is transferred.

[0021] In the above configuration, the heat from the chip-on-board light-emitting diode is dissipated via the heat dissipation member, so that an excessive temperature rise in the chip-on-board light-emitting diode is suppressed.

[0022] In one or more embodiments, the power tool may include a reduction mechanism that transmits rotational force of the motor to the output shaft, and a gear case that houses the reduction mechanism. The heat dissipation member may include the gear case.

[0023] In the above configuration, the heat of the chip-on-board light-emitting diode is dissipated through the gear case.

[0024] In one or more embodiments, the power tool may include a thermally conductive material that transfers heat from the chip-on-board light emitting diode to the gear case.

[0025] In the above configuration, the heat of the chip-on-board light-emitting diode is efficiently transferred to the gear case via the heat conductive material.

[0026] In one or more embodiments, the thermally conductive material may contact each of the substrate of the chip-on-board light emitting diode and the gear case.

[0027] In the above configuration, the heat of the chip-on-board light-emitting diode is efficiently transferred to the gear case via the heat conductive material.

[0028] In one or more embodiments, the thermally conductive material may be in sheet form.

[0029] In the above configuration, when the thermally conductive material is a solid thermally conductive sheet, the substrate of the chip-on-board light-emitting diode and the gear case can sandwich the thermally conductive sheet.

[0030] In one or more embodiments, the gear case may include a rear cylindrical portion that houses the reduction mechanism, a front cylindrical portion that holds a bearing that supports the output shaft, and an annular portion that connects the front end of the rear cylindrical portion to the rear end of the front cylindrical portion. The chip-on-board light-emitting diode may be disposed around the front cylindrical portion. A thermally conductive material may be in contact with each of the substrate and the annular portion.

[0031] In the above configuration, the power tool is prevented from becoming large, and the heat of the chip-on-board light-emitting diode is efficiently transferred to the annular portion of the gear case via the thermally conductive material.

[0032] In one or more embodiments, the power tool may include a case cover covering a surface of the rear barrel portion. The heat dissipation member may include the case cover. The thermally conductive material may be in contact with the case cover.

[0033] In the above configuration, the heat from the chip-on-board light-emitting diode is efficiently dissipated through the case cover.

[0034] In one or more embodiments, the heat dissipation member may contact the substrate of the chip-on-board light emitting diode.

[0035] In the above configuration, the heat from the chip-on-board light-emitting diode is efficiently transferred to the heat dissipation member.

[0036] In one or more embodiments, the LED chip of the chip-on-board light emitting diode may be disposed on the front surface of the substrate, and the heat dissipation member may include a heat sink in contact with the rear surface of the substrate.

[0037] In the above configuration, the heat from the chip-on-board light-emitting diode is efficiently dissipated through the heat sink.

[0038] In one or more embodiments, the gear case may include a rear cylindrical portion that houses the reduction mechanism, a front cylindrical portion that holds a bearing that supports the output shaft, and an annular portion that connects the front end of the rear cylindrical portion to the rear end of the front cylindrical portion. The chip-on-board light-emitting diode may be disposed around the front cylindrical portion. The heat sink may face the annular portion with a gap therebetween.

[0039] In the above configuration, the heat from the chip-on-board light-emitting diode is efficiently dissipated into the atmosphere via the heat sink.

[0040] In one or more embodiments, the power tool may include a case cover that covers a surface of the rear barrel portion, and the heat sink may face the case cover with a gap therebetween.

[0041] In the above configuration, the heat from the chip-on-board light-emitting diode is efficiently dissipated into the atmosphere via the heat sink.

[0042] In one or more embodiments, the power tool may include a light cover having a light-transmitting portion through which light emitted from the LED chip of the chip-on-board light-emitting diode passes. The heat dissipation member may include the light cover.

[0043] In the above configuration, the heat of the chip-on-board light-emitting diode is efficiently dissipated through the light cover.

[0044] In one or more embodiments, the substrate may have an annular portion, and the LED chip may be disposed on a front surface of the annular portion. The light cover may have an outer cylindrical portion disposed radially outward from the annular portion, and an inner cylindrical portion disposed radially inward from the annular portion. The light-transmitting portion may be disposed so as to connect a front end of the outer cylindrical portion with a front end of the inner cylindrical portion. The substrate may be in contact with at least one of the outer cylindrical portion and the inner cylindrical portion while being spaced apart from the light-transmitting portion.

[0045] In the above configuration, the heat of the chip-on-board light-emitting diode is efficiently transferred to the light cover.

[0046] In one or more embodiments, the substrate of the chip-on-board light-emitting diode may be fixed to the heat dissipation member via an adhesive, and heat from the chip-on-board light-emitting diode may be transferred to the heat dissipation member via the adhesive.

[0047] In the above configuration, the heat from the chip-on-board light-emitting diode is efficiently transferred to the heat dissipation member via the adhesive.

[0048] In one or more embodiments, the power tool may include a light cover having a light-transmitting portion through which light emitted from the LED chip of the chip-on-board light-emitting diode passes. The heat dissipation member may include the light cover.

[0049] In the above configuration, the heat of the chip-on-board light-emitting diode is efficiently transferred to the light cover via the adhesive.

[0050] In one or more embodiments, the substrate may have an annular portion, and the LED chip may be disposed on a front surface of the annular portion. The light cover may have an outer cylindrical portion disposed radially outward from the annular portion, and an inner cylindrical portion disposed radially inward from the annular portion. The light-transmitting portion may be disposed so as to connect a front end of the outer cylindrical portion with a front end of the inner cylindrical portion. The substrate may be fixed to the inner cylindrical portion via an adhesive.

[0051] In the above configuration, the heat of the chip-on-board light-emitting diode is efficiently transferred to the light cover via the adhesive.

[0052] In one or more embodiments, the gear case may include a rear cylindrical portion that houses the reduction mechanism, a front cylindrical portion that holds a bearing that supports the output shaft, and an annular portion that connects a front end portion of the rear cylindrical portion to a rear end portion of the front cylindrical portion. The inner cylindrical portion may be disposed around the front cylindrical portion and fixed to the front cylindrical portion.

[0053] In the above configuration, the chip-on-board light-emitting diode is fixed to the front cylinder portion of the gear case via the light cover.

[0054] In one or more embodiments, the output shaft may include an anvil. The power tool may include a striking mechanism to which rotational force of the motor is transmitted via a reduction mechanism and which strikes the anvil in a rotational direction. The gear case may be a hammer case that houses the reduction mechanism and the striking mechanism.

[0055] In the above configuration, the chip-on-board light emitting diode is applied to an impact tool.

[0056] In one or more embodiments, the power tool may include a fan that rotates due to the rotational force of the motor. The heat dissipation device may include the fan. Air may be supplied from the fan to the chip-on-board light-emitting diode.

[0057] In the above configuration, the heat of the chip-on-board light-emitting diodes is dissipated by the air supplied by the fan.

[0058] Hereinafter, embodiments will be described with reference to the drawings. In the embodiments, 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 power tool.

[0059] [First embodiment] <Power tools> Fig. 1 is a front perspective view of a power tool 1 according to this embodiment. Fig. 2 is a side view of the power tool 1 according to this embodiment. Fig. 3 is a cross-sectional view of the power tool 1 according to this embodiment. Fig. 4 is a cross-sectional view of the upper part of the power tool 1 according to this embodiment.

[0060] In this embodiment, the power tool 1 is an electric tool having an electric motor 6 as a power source. A direction parallel to the rotation axis AX of the motor 6 is referred to as the axial direction, a direction circumferentially around the rotation axis AX is referred to as the circumferential direction or rotation direction, and a radial direction of the rotation axis AX is referred to as the radial direction. In addition, in the radial direction, a position closer to or approaching the rotation axis AX is referred to as the radially inner direction, and a position farther from or away from the rotation axis AX is referred to as the radially outer direction. In this embodiment, 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.

[0061] In this embodiment, the power tool 1 is an impact tool, which is a type of electric power tool. In the following description, the power tool 1 will be referred to as the impact tool 1 where appropriate.

[0062] In this 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 case cover 5, 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 hand mode switch button 16, a controller 17, and a light unit 18.

[0063] 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.

[0064] The housing 2 has a motor accommodating portion 21, a grip portion 22, and a battery holding portion 23.

[0065] The motor housing portion 21 is cylindrical and houses the motor 6, a part of the bearing box 24, and the rear part of the hammer case 4.

[0066] The grip portion 22 protrudes downward from the motor housing portion 21. The trigger lever 14 is provided on the upper portion of the grip portion 22. The grip portion 22 is held by an operator.

[0067] The battery holding portion 23 is connected to the lower end 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.

[0068] The rear cover 3 is made of synthetic resin. The rear cover 3 is disposed behind the motor housing portion 21. The rear cover 3 accommodates at least a portion of the fan 12. The fan 12 is disposed on the inner peripheral side of the rear cover 3. The rear cover 3 is disposed so as to cover the opening at the rear end of the motor housing portion 21.

[0069] 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.

[0070] The hammer case 4 functions as a gear case that houses the reduction mechanism 7. The hammer case 4 houses at least a part of the reduction mechanism 7, the spindle 8, the striking mechanism 9, and 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.

[0071] The hammer case 4 includes a rear-side tubular portion 4A, a front-side tubular portion 4B, and an annular portion 4C. The front-side tubular portion 4B is disposed forward of the rear-side tubular portion 4A. The outer diameter of the rear-side tubular portion 4A is larger than the outer diameter of the front-side tubular portion 4B. The inner diameter of the rear-side tubular portion 4A is larger than the inner diameter of the front-side tubular portion 4B. The annular portion 4C is disposed to connect the front end of the rear-side tubular portion 4A and the rear end of the front-side tubular portion 4B.

[0072] The hammer case 4 is connected to the front part of the motor accommodating section 21. A bearing box 24 is fixed to the rear part of the rear side cylindrical section 4A. At least a part of the reduction mechanism 7 is arranged inside the bearing box 24. A screw thread is formed on the outer periphery of the bearing box 24. A screw groove is formed on the inner periphery of the rear part of the rear side cylindrical section 4A. The screw thread of the bearing box 24 and the screw groove of the rear side cylindrical section 4A are coupled together, thereby fixing the bearing box 24 and the hammer case 4. The hammer case 4 is sandwiched between the left housing 2L and the right housing 2R. A part of the bearing box 24 and the rear part of the rear side cylindrical section 4A are housed in the motor accommodating section 21. The bearing box 24 is fixed to both the motor accommodating section 21 and the hammer case 4.

[0073] The case cover 5 covers at least a portion of the surface of the hammer case 4. In this embodiment, the case cover 5 covers the surface of the rear side tubular portion 4A. The case cover 5 is made of synthetic resin. In this embodiment, the case cover 5 is made of polycarbonate resin. The case cover 5 protects the hammer case 4. The case cover 5 prevents contact between the hammer case 4 and objects around the impact tool 1. The case cover 5 prevents contact between the hammer case 4 and the worker.

[0074] The motor 6 is a power source of the impact tool 1. The motor 6 generates rotational force. The motor 6 is an electric motor. The motor 6 is an inner rotor type brushless motor. The motor 6 has a stator 26 and a rotor 27. The stator 26 is supported by the motor accommodating portion 21. At least a portion of the rotor 27 is disposed inside the stator 26. The rotor 27 rotates relative to the stator 26. The rotor 27 rotates around a rotation axis AX extending in the front-rear direction.

[0075] The stator 26 includes a stator core 28 , a front insulator 29 , a rear insulator 30 , and a coil 31 .

[0076] The stator core 28 is disposed radially outward of the rotor 27. The stator core 28 includes a plurality of stacked steel plates. The steel plates are metal plates whose main component is iron. The stator core 28 is cylindrical. The stator core 28 has a plurality of teeth that support the coils 31.

[0077] The front insulator 29 is provided in the front portion of the stator core 28. The rear insulator 30 is provided in the rear portion of the stator core 28. The front insulator 29 and the rear insulator 30 are each an electrical insulating member made of synthetic resin. The front insulator 29 is arranged so as to cover part of the surface of the teeth. The rear insulator 30 is arranged so as to cover part of the surface of the teeth.

[0078] The coil 31 is attached to the stator core 28 via the front insulator 29 and the rear insulator 30. Multiple coils 31 are arranged. The coils 31 are arranged around the teeth of the stator core 28 via the front insulator 29 and the rear insulator 30. The coils 31 and the stator core 28 are electrically insulated by the front insulator 29 and the rear insulator 30. The multiple coils 31 are connected via fusing terminals 38.

[0079] The rotor 27 rotates about a rotation axis AX and includes a rotor core portion 32, a rotor shaft portion 33, a rotor magnet , and a sensor magnet .

[0080] The rotor core portion 32 and the rotor shaft portion 33 are each made of steel. In this embodiment, the rotor core portion 32 and the rotor shaft portion 33 are integral. A front portion of the rotor shaft portion 33 protrudes forward from the front end surface of the rotor core portion 32. A rear portion of the rotor shaft portion 33 protrudes rearward from the rear end surface of the rotor core portion 32.

[0081] The rotor magnet 34 is fixed to the rotor core portion 32. The rotor magnet 34 is cylindrical. The rotor magnet 34 is arranged around the rotor core portion 32.

[0082] The sensor magnet 35 is fixed to the rotor core portion 32. The sensor magnet 35 has an annular shape. The sensor magnet 35 is disposed on the front end surface of the rotor core portion 32 and the front end surface of the rotor magnet 34.

[0083] A sensor board 37 is attached to the front insulator 29. The sensor board 37 is fixed to the front insulator 29 with screws 29S. The sensor board 37 has an annular circuit board and a magnetic sensor supported by the circuit board. At least a portion of the sensor board 37 faces the sensor magnet 35. The magnetic sensor detects the position of the sensor magnet 35, thereby detecting the position of the rotor 27 in the rotational direction.

[0084] The rear portion of the rotor shaft portion 33 is rotatably supported by a rotor bearing 39. The front portion of the rotor bearing 39 is rotatably supported by a rotor bearing 40. The rotor bearing 39 is held by the rear cover 3. The rotor bearing 40 is held by the bearing box 24. The front end portion of the rotor shaft portion 33 is disposed in the internal space of the hammer case 4 through the opening of the bearing box 24.

[0085] A pinion gear 41 is formed on the front end of the rotor shaft portion 33. The pinion gear 41 is connected to at least a part of the reduction mechanism 7. The rotor shaft portion 33 is connected to the reduction mechanism 7 via the pinion gear 41.

[0086] The reduction mechanism 7 transmits the rotational force of the motor 6 to the spindle 8 and the anvil 10. The reduction mechanism 7 is housed in the rear cylindrical portion 4A of the hammer case 4. The reduction mechanism 7 has a plurality of gears. The reduction mechanism 7 is disposed forward of the motor 6. The reduction mechanism 7 connects the rotor shaft portion 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 portion 33. The reduction mechanism 7 includes a planetary gear mechanism.

[0087] The reduction mechanism 7 has a plurality of planetary gears 42 arranged around a 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 housed in the hammer case 4 and the bearing box 24, respectively. Each of the plurality of planetary gears 42 meshes with the pinion gear 41. The planetary gear 42 is rotatably supported on the spindle 8 via a pin 42P. The spindle 8 is rotated by the planetary gear 42. The internal gear 43 has internal teeth that mesh with the planetary gear 42. The internal gear 43 is fixed to the bearing box 24. The internal gear 43 is always non-rotatable relative to the bearing box 24.

[0088] When the rotor shaft portion 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 portion 33.

[0089] The spindle 8 rotates due to the rotational force of the motor 6. The spindle 8 is disposed forward of at least a portion of the motor 6. The spindle 8 is disposed forward of the stator 26. At least a portion of the spindle 8 is disposed forward of the rotor 27. At least a portion of the spindle 8 is disposed forward of the reduction mechanism 7. The spindle 8 is rotated by the rotor 27. The spindle 8 rotates due to the rotational force of the rotor 27 transmitted by the reduction mechanism 7.

[0090] The spindle 8 has a flange portion 8A and a spindle shaft portion 8B that protrudes forward from the flange portion 8A. The planetary gear 42 is rotatably supported on the flange portion 8A via a pin 42P. The rotation axis of the spindle 8 coincides with the rotation axis AX of the motor 6. The spindle 8 rotates around the rotation axis AX.

[0091] The spindle 8 is rotatably supported by a spindle bearing 44. The spindle bearing 44 is held in the bearing box 24. The spindle 8 has a circular ring portion 8C that protrudes rearward from the rear of the flange portion 8A. The spindle bearing 44 is disposed inside the circular ring portion 8C. In this embodiment, the outer ring of the spindle bearing 44 is connected to the circular ring portion 8C, and the inner ring of the spindle bearing 44 is supported by the bearing box 24.

[0092] 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, and a coil spring 49. The striking mechanism 9 including the hammer 47 is housed in a hammer case 4.

[0093] The hammer 47 is disposed forward of the reduction mechanism 7. The hammer 47 is housed in the rear cylindrical portion 4A. The hammer 47 is disposed around the spindle shaft portion 8B. The hammer 47 is held by the spindle shaft portion 8B. The ball 48 is disposed between the spindle shaft portion 8B and the hammer 47. The coil spring 49 is supported by each of the flange portion 8A and the hammer 47.

[0094] 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.

[0095] The ball 48 is made of a metal such as steel. The ball 48 is disposed between the spindle shaft portion 8B and the hammer 47. The spindle 8 has a spindle groove 8D in which at least a portion of the ball 48 is disposed. The spindle groove 8D is provided on a portion of the outer circumferential surface of the spindle shaft portion 8B. The hammer 47 has a hammer groove 47A in which at least a portion of the ball 48 is disposed. The hammer groove 47A is provided on a portion of the inner surface of the hammer 47. The ball 48 is disposed between the spindle groove 8D and the hammer groove 47A. The ball 48 can roll inside the spindle groove 8D and inside the hammer groove 47A. The hammer 47 is movable along with the ball 48. The spindle 8 and the hammer 47 can move relative to each other in the axial direction and the rotational direction within a movable range defined by the spindle groove 8D and the hammer groove 47A.

[0096] The coil spring 49 generates an elastic force that moves the hammer 47 forward. The coil spring 49 is disposed between the flange portion 8A and the hammer 47. A ring-shaped recess 47C is provided on the rear surface of the hammer 47. The recess 47C is recessed forward from the rear surface of the hammer 47. A washer 45 is provided inside the recess 47C. The rear end of the coil spring 49 is supported by the flange portion 8A. The front end of the coil spring 49 is disposed inside the recess 47C and supported by the washer 45.

[0097] The anvil 10 is the output shaft of the impact tool 1 that rotates due to the rotational force of the motor 6. At least a portion of the anvil 10 is positioned forward of the hammer 47. The anvil 10 has a tool hole 10A into which a tool bit is inserted. The tool hole 10A is provided at the front end of the anvil 10. The tool bit is attached to the anvil 10. A protrusion 10B is provided at the rear end of the anvil 10. A recess is provided at the front end of the spindle shaft portion 8B. The protrusion 10B is inserted into the recess provided at the front end of the spindle shaft portion 8B.

[0098] The anvil 10 has a rod-shaped anvil shaft portion 10C and an anvil protrusion portion 10D. The tool hole 10A is provided at the front end of the anvil shaft portion 10C. A tool tip is attached to the anvil shaft portion 10C. The anvil protrusion portion 10D is provided at the rear end of the anvil 10. The anvil protrusion portion 10D protrudes radially outward from the rear end of the anvil shaft portion 10C.

[0099] 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 all coincident. The anvil 10 rotates around the rotation axis AX. The anvil bearing 46 is disposed inside the front cylindrical portion 4B. The anvil bearing 46 is held by the front cylindrical portion 4B of the hammer case 4. The anvil bearing 46 supports the anvil shaft portion 10C. In this embodiment, two anvil bearings 46 are disposed in the front-to-rear direction.

[0100] At least a portion of the hammer 47 is capable of contacting the anvil protrusion 10D. A hammer protrusion that protrudes forward is provided at the front of the hammer 47. The hammer protrusion of the hammer 47 and the anvil protrusion 10D are capable of contacting each other. When the motor 6 is driven while the hammer 47 and the anvil protrusion 10D are in contact with each other, the anvil 10 rotates together with the hammer 47 and the spindle 8.

[0101] 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 arise in which the anvil 10 cannot be rotated by the power generated by the motor 6 alone. When the power generated by the motor 6 alone is no longer sufficient to 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 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 rearward while being guided by the spindle groove 8D and the hammer groove 47A. The hammer 47 receives force from the ball 48 and moves rearward along with the ball 48. In other words, when the rotation of the anvil 10 is stopped, the hammer 47 moves rearward due to the rotation of the spindle 8. As the hammer 47 moves rearward, the contact between the hammer 47 and the anvil protrusion 10D is released.

[0102] The coil spring 49 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. As the hammer 47 moves forward, it receives a rotational force from the ball 48. That is, the hammer 47 moves forward while rotating. As the hammer 47 moves forward while rotating, it comes into contact with the anvil protrusion 10D while rotating. As a result, the anvil protrusion 10D is struck in the rotational direction by the hammer 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.

[0103] The tool holding mechanism 11 is disposed around the front portion of the anvil 10. The tool holding mechanism 11 holds the tool bit inserted into the tool hole 10A.

[0104] The fan 12 rotates due to the rotational force of the motor 6. 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 rotor bearing 39 and the stator 26. The fan 12 rotates due to the rotation of the rotor 27. As the rotor shaft 33 rotates, the fan 12 rotates together with the rotor shaft 33. As the fan 12 rotates, air 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 a 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 functions as a power source for the impact tool 1. The battery pack 25 includes a secondary battery. In this 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 and the light unit 18 are each 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 hand mode switching button 16 is provided on the upper part of the trigger lever 14. The hand mode switching button 16 is operated by an operator. By operating the hand mode switching button 16, the control mode of the motor 6 is switched.

[0109] The controller 17 outputs control signals to control at least the motor 6 and the light unit 18. The controller 17 is housed in the battery holding section 23. The controller 17 switches the control mode of the motor 6 based on the work content of the impact tool 1. The control mode of the motor 6 refers to a control method or control pattern of the motor 6. The controller 17 includes a circuit board on which multiple electronic components are mounted. Examples of electronic components mounted on the circuit board include a processor such as a CPU (Central Processing Unit), a non-volatile memory such as a ROM (Read Only Memory) or storage, a volatile memory such as a RAM (Random Access Memory), transistors, and resistors.

[0110] <Light unit> The light unit 18 emits illumination light. The light unit 18 illuminates the anvil 10 and the area around the anvil 10 with the illumination light. The light unit 18 illuminates the area in front of the anvil 10 with the illumination light. The light unit 18 also illuminates the tool tip attached to the anvil 10 and the area around the tool tip with the illumination light.

[0111] The light unit 18 is disposed in the front part of the hammer case 4. The light unit 18 is disposed around the front cylinder portion 4B.

[0112] The light unit 18 includes chip on board light emitting diodes (COB LEDs).

[0113] FIG. 5 is a schematic diagram illustrating a chip-on-board light-emitting diode 50 according to this embodiment. The chip-on-board light-emitting diode 50 includes a substrate 51, an LED chip 52, gold wires 53, a bank 54, a phosphor 55, and a pair of electrodes 56. The substrate 51 may be, for example, an aluminum substrate, a glass cloth-based epoxy resin substrate (FR-4 substrate), or a composite substrate epoxy resin substrate (CEM-3 substrate). The LED chip 52 is mounted on the surface of the substrate 51. The gold wires 53 connect the LED chip 52 to the substrate 51. The gold wires 53 connect the multiple LED chips 52 to each other. The bank 54 is provided on the surface of the substrate 51. The bank 54 is disposed around the LED chip 52. The bank 54 defines a compartment in which the phosphor 55 is disposed. The phosphor 55 is disposed inside the bank 54 so as to cover the LED chip 52. The electrode 56 is disposed on the surface of the substrate 51 outside the bank 54. The electrode 56 may be disposed on the back surface of the substrate 51. Of the pair of electrodes 56, one electrode 56 is a positive electrode 56A and the other electrode 56 is a negative electrode 56B. The electrode 56 is connected to the battery pack 25 via the controller 17 and lead wires. Power output from the battery pack 25 is supplied to the electrode 56 via the controller 17 and lead wires. The power supplied to the electrode 56 is supplied to the LED chip 52 via the substrate 51 and gold wires 53. The LED chip 52 emits light based on the power supplied from the battery pack 25. The voltage of the battery pack 25 is stepped down to 5 V by the controller 17 and applied to the LED chip 52.

[0114] Fig. 6 is a perspective view of the light unit 18 according to this embodiment, seen from the front. Fig. 7 is a perspective view of the light unit 18 according to this embodiment, seen from the rear. Fig. 8 is an exploded perspective view of the light unit 18 according to this embodiment, seen from the front. Fig. 9 is an exploded perspective view of the light unit 18 according to this embodiment, seen from the rear.

[0115] 6, 7, 8, and 9, the light unit 18 includes a chip-on-board light-emitting diode 50 and a light cover 57. The chip-on-board light-emitting diode 50 includes a substrate 51, a plurality of LED chips 52, a bank 54, a phosphor 55, and a pair of electrodes 56.

[0116] The substrate 51 has an annular portion 51A and a support portion 51B that protrudes downward from the bottom of the annular portion 51A.

[0117] The LED chips 52 are disposed on the front surface of the annular portion 51A of the substrate 51. A plurality of the LED chips 52 are disposed at intervals in the circumferential direction of the annular portion 51A. In this embodiment, 12 LED chips 52 are disposed at equal intervals in the circumferential direction of the annular portion 51A.

[0118] In this embodiment, the number of LED chips 52 is 12, but it may be more than 12, for example, 24 or 36. The number of LED chips 52 may be a multiple of six.

[0119] The bank 54 is provided on the front surface of the annular portion 51A of the substrate 51. The bank 54 protrudes forward from the front surface of the annular portion 51A. The bank 54 has an annular shape. In this embodiment, the bank 54 is provided in the form of a double annular ring. That is, in this embodiment, the bank 54 includes a first bank 54 and a second bank 54 arranged radially outward from the first bank 54. The first bank 54 is arranged radially inward from the LED chips 52. The second bank 54 is arranged radially outward from the LED chips 52.

[0120] The phosphor 55 is disposed on the front surface of the annular portion 51A of the substrate 51. The phosphor 55 is annular. The phosphor 55 is disposed between the first bank 54 and the second bank 54. The phosphor 55 is disposed so as to cover each of the plurality of LED chips 52.

[0121] The electrodes 56 are arranged on the rear surface of the substrate 51. In this embodiment, the electrodes 56 are arranged on the rear surface of the annular portion 51A. The electrodes 56 are connected to the controller 17 via lead wires 58. One lead wire 58 is connected to each of the pair of electrodes 56. The pair of lead wires 58 are supported on the rear surface of the support portion 51B. Note that the electrodes 56 may be arranged on, for example, the front surface of the support portion 51B. The lead wires 58 may be supported on the front surface of the support portion 51B.

[0122] The current output from the battery pack 25 is supplied to the electrode 56 via the controller 17 and the lead wire 58. The current supplied to the electrode 56 is supplied to the LED chip 52 via the substrate 51 and the gold wire 53 (not shown in FIGS. 6 to 9). The LED chip 52 emits light based on the current supplied from the battery pack 25.

[0123] FIG. 10 is a rear view of the light cover 57 according to this embodiment. The light cover 57 is connected to the chip-on-board light-emitting diodes 50. The light cover 57 is fixed to the substrate 51. The light cover 57 is made of polycarbonate resin. The light cover 57 is transparent. The light cover 57 may also be translucent and light white. At least a portion of the light cover 57 is disposed forward of the chip-on-board light-emitting diodes 50. The light cover 57 has an outer cylinder portion 57A, an inner cylinder portion 57B, a light-transmitting portion 57C, and a support portion 57D.

[0124] The outer cylinder portion 57A is disposed radially outward of the inner cylinder portion 57B. At least a portion of the chip-on-board light-emitting diode 50 is disposed radially between the outer cylinder portion 57A and the inner cylinder portion 57B. The outer cylinder portion 57A is disposed radially outward of the annular portion 51A of the substrate 51. The inner cylinder portion 57B is disposed radially inward of the annular portion 51A of the substrate 51.

[0125] The light-transmitting portion 57C has an annular shape. The light-transmitting portion 57C is arranged to connect the front end of the outer cylinder portion 57A and the front end of the inner cylinder portion 57B. The light-transmitting portion 57C faces the front surface of the annular portion 51A. The light-transmitting portion 57C faces the LED chip 52. Light emitted from the LED chip 52 passes through the light-transmitting portion 57C and is irradiated toward the front of the light unit 18.

[0126] The light-transmitting portion 57C has an incident surface 57E through which light from the LED chip 52 enters and an exit surface 57F through which light transmitted through the light-transmitting portion 57C exits. The incident surface 57E faces the LED chip 52. The incident surface 57E faces substantially backward. The exit surface 57F faces substantially forward.

[0127] Support portion 57D is provided so as to protrude downward from the lower part of outer cylinder portion 57A. Recessed portion 57G is formed inside support portion 57D. Support portion 51B of substrate 51 is disposed in recessed portion 57G. Two notches 57H are formed in support portion 57D. Lead wires 58 are disposed inside notches 57H.

[0128] Fig. 11 is a view of the upper part of the power tool 1 according to this embodiment as seen from the front. Fig. 12 is an exploded perspective view of the upper part of the power tool 1 according to this embodiment as seen from the front. Fig. 13 is an exploded perspective view of the upper part of the power tool 1 according to this embodiment as seen from the rear. Fig. 14 is a cross-sectional view of a part of the power tool 1 according to this embodiment.

[0129] The light unit 18 including the chip-on-board light emitting diodes 50 is disposed around the anvil shaft portion 10C of the anvil 10. The light unit 18 including the chip-on-board light emitting diodes 50 is disposed around the front cylinder portion 4B of the hammer case 4. The inner cylinder portion 57B of the light cover 57 is disposed around the front cylinder portion 4B of the hammer case 4. The inner cylinder portion 57B of the light cover 57 is fixed to the front cylinder portion 4B of the hammer case 4.

[0130] The substrate 51 is fixed to the light cover 57. The substrate 51 is disposed between the outer cylindrical portion 57A and the inner cylindrical portion 57B in the radial direction. As shown in FIGS. 9 and 10 , a support protrusion 57J is provided on the outer peripheral surface of the inner cylindrical portion 57B. The support protrusion 57J protrudes radially outward from the outer peripheral surface of the inner cylindrical portion 57B. A plurality of the support protrusions 57J are provided at intervals in the circumferential direction. As shown in FIG. 10 , in this embodiment, three support protrusions 57J are provided at intervals in the circumferential direction. The inner peripheral surface of the annular portion 51A of the substrate 51 is supported by the support protrusions 57J. The substrate 51 is fixed to the inner cylindrical portion 57B via an adhesive 59. In this embodiment, the rear surface of the substrate 51 and the outer peripheral surface of the inner cylindrical portion 57B are fixed together with the adhesive 59.

[0131] A protrusion 4D is provided on the outer peripheral surface of the front-side tubular portion 4B. The protrusion 4D protrudes radially outward from the outer peripheral surface of the front-side tubular portion 4B. A plurality of the protrusions 4D are provided at intervals in the circumferential direction. In this embodiment, four protrusions 4D are provided at intervals in the circumferential direction. The surface of the protrusion 4D includes a rear surface 4E facing rearward and an inclined surface 4F that slopes radially inward toward the front.

[0132] The light cover 57 is fixed to the front cylindrical portion 4B of the hammer case 4. A rear slide portion 57M and a front slide portion 57N are provided on the inner peripheral surface of the inner cylindrical portion 57B of the light cover 57. The rear slide portion 57M and the front slide portion 57N each protrude radially inward from the inner peripheral surface of the inner cylindrical portion 57B. The front slide portion 57N is disposed forward of the rear slide portion 57M. As shown in FIG. 10 , four rear slide portions 57M are provided at intervals in the circumferential direction. The front slide portions 57N are disposed forward of each of the four rear slide portions 57M. A recess 57K is provided between the rear slide portion 57M and the front slide portion 57N. The protrusion 4D is disposed inside the recess 57K. The rear slide portion 57M has a front surface 57P that contacts the rear surface 4E of the protrusion 4D. The front slide portion 57N has a slope 57Q that faces the slope 4F of the protrusion 4D.

[0133] An insertion opening is provided between one circumferential end of the rear slide portion 57M and the front slide portion 57N. The protrusion 4D is disposed in the recess 57K through the insertion opening. After the protrusion 4D is inserted into the insertion opening, the light unit 18 is rotated, whereby the protrusion 4D is inserted into the inside of the recess 57K. This fixes the light cover 57 and the front cylinder portion 4B of the hammer case 4. Fixing the light cover 57 and the front cylinder portion 4B of the hammer case 4 fixes the light unit 18 and the hammer case 4.

[0134] Light emitted from LED chip 52 is incident on incident surface 57E via phosphor 55. As shown in Fig. 14, incident surface 57E is inclined forward and radially inward. The light incident on incident surface 57E passes through light-transmitting portion 57C and then exits from exit surface 57F.

[0135] As indicated by arrow FL in FIG. 14, at least a portion of the light incident on incident surface 57E reaches inclined surface 57Q. Inclined surface 57Q is inclined forward in the radially inward direction. The light that reaches inclined surface 57Q is totally reflected by inclined surface 57Q and travels forward. The light that is totally reflected by inclined surface 57Q is emitted from exit surface 57F.

[0136] In this embodiment, the impact tool 1 is provided with a heat dissipation device that dissipates heat from the chip-on-board light-emitting diode 50. The heat dissipation device includes a heat dissipation member to which the heat from the chip-on-board light-emitting diode 50 is transferred. In this embodiment, the heat dissipation member includes the hammer case 4.

[0137] In this embodiment, the heat of the chip-on-board light-emitting diode 50 is transferred to the hammer case 4 via a thermal interface material 60 (TIM). The thermal interface material 60 is disposed between the hammer case 4 and the light unit 18. The thermal interface material 60 contacts both the substrate 51 of the chip-on-board light-emitting diode 50 and the hammer case 4.

[0138] In this embodiment, the thermally conductive material 60 is disposed between the rear surface of the substrate 51 and the front surface of the annular portion 4C. The thermally conductive material 60 contacts both the rear surface of the substrate 51 and the front surface of the annular portion 4C. The thermal conductivity of the thermally conductive material 60 is higher than that of air. The thermal conductivity of the thermally conductive material 60 is higher than that of the substrate 51. The thermal conductivity of the thermally conductive material 60 is higher than that of the light cover 57. The thermally conductive material 60 is electrically insulating.

[0139] The thermally conductive material 60 may be a coating applied to one or both of the substrate 51 and the hammer case 4, or may be in the form of a solid sheet. In this embodiment, the thermally conductive material 60 is a solid sheet-like member. In the following description, the thermally conductive material 60 will be referred to as the thermally conductive sheet 60 as appropriate.

[0140] The thermally conductive sheet 60 is annular. The thermally conductive sheet 60 has an annular portion 60A that contacts the rear surface of the annular portion 51A of the substrate 51, and a protruding portion 60B that contacts the rear surface of the support portion 51B of the substrate 51. The protruding portion 60B protrudes downward from the lower portion of the annular portion 60A.

[0141] When the trigger lever 14 is operated, the motor 6 starts and light is emitted from the LED chip 52 of the chip-on-board light-emitting diode 50. The amount of light output from the chip-on-board light-emitting diode 50 is high, allowing the work object to be brightly illuminated.

[0142] On the other hand, since the chip-on-board light-emitting diode 50 generates a large amount of heat, the temperature of the chip-on-board light-emitting diode 50 may rise excessively. If the temperature of the chip-on-board light-emitting diode 50 exceeds the allowable value, the LED chip 52 may deteriorate, and the life of the chip-on-board light-emitting diode 50 may be shortened. The allowable value for the temperature of the chip-on-board light-emitting diode 50 is, for example, the heat resistance temperature of the LED chip 52.

[0143] The component that generates the most heat in the chip-on-board light-emitting diode 50 is the LED chip 52. The LED chip 52 is disposed in a space surrounded by the substrate 51 and the light cover 57. The heat of the LED chip 52 is unlikely to escape from the space surrounded by the substrate 51 and the light cover 57. In this embodiment, the heat of the LED chip 52 is transferred to the hammer case 4 via the substrate 51 and the thermally conductive sheet 60. The heat of the chip-on-board light-emitting diode 50 transferred to the hammer case 4 is dissipated into the atmospheric space surrounding the hammer case 4. This prevents the chip-on-board light-emitting diode 50 from excessively increasing in temperature.

[0144] The heat dissipation member may include the case cover 5. The thermally conductive sheet 60 contacts both the annular portion 4C of the hammer case 4 and the front end portion of the case cover 5. The heat from the chip-on-board light-emitting diodes 50 transferred to the case cover 5 is dissipated into the atmospheric space surrounding the case cover 5.

[0145] The thermally conductive sheet 60 may be separated from the case cover 5. The heat of the chip-on-board light-emitting diodes 50 transmitted to the hammer case 4 via the thermally conductive sheet 60 is dissipated via the case cover 5 into the atmospheric space around the case cover 5.

[0146] The heat dissipation member may include the light cover 57. The substrate 51 is in contact with at least one of the outer cylinder portion 57A and the inner cylinder portion 57B while being spaced apart from the light-transmitting portion 57C. After the heat of the chip-on-board light-emitting diode 50 is transferred to the light cover 57, it may be dissipated from the light cover 57 to the atmosphere. Alternatively, the heat of the chip-on-board light-emitting diode 50 may be transferred to the light cover 57 via an adhesive 59.

[0147] In this embodiment, the driving voltage of the light unit 18 is 5 V. The luminous flux of the light unit 18 is 50 lumens or more and 200 lumens or less. The luminous flux of the light unit 18 may be 80 lumens or more and 150 lumens or less, or 100 lumens or more and 130 lumens or less.

[0148] <Effects> As described above, in this embodiment, the impact tool 1 may include a motor 6, an anvil 10 that rotates by the rotational force of the motor 6, a chip-on-board light-emitting diode 50 arranged around the anvil 10, and a heat dissipation device that dissipates heat from the chip-on-board light-emitting diode 50.

[0149] In the above configuration, the heat generated by the chip-on-board light-emitting diode 50 is dissipated by the heat dissipation device, so that an excessive temperature rise in the chip-on-board light-emitting diode 50 is suppressed.

[0150] In this embodiment, the heat dissipation device may include a heat dissipation member to which the heat of the chip-on-board light emitting diode 50 is transferred.

[0151] In the above configuration, the heat generated by the chip-on-board light-emitting diode 50 is dissipated via the heat dissipation member, so that an excessive temperature rise in the chip-on-board light-emitting diode 50 is suppressed.

[0152] In the present embodiment, the impact tool 1 may include a speed reduction mechanism 7 that transmits the rotational force of the motor 6 to the anvil 10, and a hammer case 4 that houses the speed reduction mechanism 7. The heat dissipation member may include the hammer case 4.

[0153] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is dissipated through the hammer case 4.

[0154] In this embodiment, the impact tool 1 may include a heat-conducting material 60 that transfers heat from the chip-on-board light-emitting diode 50 to the hammer case 4 .

[0155] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the hammer case 4 via the heat conductive material 60 .

[0156] In this embodiment, the thermally conductive material 60 may contact the substrate 51 of the chip-on-board light-emitting diode 50 and the hammer case 4, respectively.

[0157] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the hammer case 4 via the heat conductive material 60 .

[0158] In this embodiment, the heat conductive material 60 may be in the form of a sheet.

[0159] In the above configuration, when the thermally conductive material 60 is a solid thermally conductive sheet 60, the substrate 51 of the chip-on-board light-emitting diode 50 and the hammer case 4 can sandwich the thermally conductive sheet 60 therebetween.

[0160] In this embodiment, the hammer case 4 may include a rear cylindrical portion 4A that houses the reduction mechanism 7, a front cylindrical portion 4B that holds an anvil bearing 46 that supports the anvil 10, and an annular portion 4C that connects the front end of the rear cylindrical portion 4A to the rear end of the front cylindrical portion 4B. The chip-on-board light-emitting diode 50 may be disposed around the front cylindrical portion 4B. The thermally conductive material 60 may be in contact with each of the substrate 51 and the annular portion 4C.

[0161] In the above-described configuration, the impact tool 1 is prevented from becoming large, and the heat from the chip-on-board light-emitting diode 50 is efficiently transferred to the annular portion 4C of the hammer case 4 via the heat conductive material 60.

[0162] In this embodiment, the impact tool 1 may include a case cover 5 that covers the surface of the rear cylinder portion 4A. The heat dissipation member may include the case cover 5. The heat conductive material 60 may be in contact with the case cover 5.

[0163] In the above configuration, the heat from the chip-on-board light-emitting diode 50 is efficiently dissipated through the case cover 5 .

[0164] In this embodiment, the substrate 51 may have an annular portion 51A, and the LED chip 52 may be disposed on the front surface of the annular portion 51A. The light cover 57 may have an outer cylinder portion 57A disposed radially outward from the annular portion 51A, and an inner cylinder portion 57B disposed radially inward from the annular portion 51A. The light transmitting portion 57C may be disposed so as to connect the front end of the outer cylinder portion 57A to the front end of the inner cylinder portion 57B. The substrate 51 may be in contact with at least one of the outer cylinder portion 57A and the inner cylinder portion 57B while being spaced apart from the light transmitting portion 57C.

[0165] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 .

[0166] In this embodiment, the substrate 51 of the chip-on-board light-emitting diode 50 may be fixed to the heat dissipation member via an adhesive 59. Heat from the chip-on-board light-emitting diode 50 may be transferred to the heat dissipation member via the adhesive 59.

[0167] In the above configuration, the heat from the chip-on-board light-emitting diode 50 is efficiently transferred to the heat dissipation member via the adhesive 59 .

[0168] In the present embodiment, the impact tool 1 may include a light cover 57 having a light-transmitting portion 57C through which light emitted from the LED chip 52 of the chip-on-board light-emitting diode 50 passes. The heat dissipation member may include the light cover 57.

[0169] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 via the adhesive 59 .

[0170] In this embodiment, the substrate 51 may have an annular portion 51A, and the LED chip 52 may be disposed on the front surface of the annular portion 51A. The light cover 57 may have an outer cylinder portion 57A disposed radially outward from the annular portion 51A, and an inner cylinder portion 57B disposed radially inward from the annular portion 51A. The light transmitting portion 57C may be disposed so as to connect the front end of the outer cylinder portion 57A to the front end of the inner cylinder portion 57B. The substrate 51 may be fixed to the inner cylinder portion 57B via an adhesive 59.

[0171] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 via the adhesive 59 .

[0172] In the present embodiment, the hammer case 4 may include a rear cylindrical portion 4A that houses the reduction mechanism 7, a front cylindrical portion 4B that holds an anvil bearing 46 that supports the anvil 10, and an annular portion 4C that connects the front end portion of the rear cylindrical portion 4A to the rear end portion of the front cylindrical portion 4B. The inner cylindrical portion 57B may be disposed around the front cylindrical portion 4B and fixed to the front cylindrical portion 4B.

[0173] In the above configuration, the chip-on-board light-emitting diode 50 is fixed to the front cylinder portion 4B of the hammer case 4 via the light cover 57.

[0174] In the present embodiment, the impact tool 1 may include a light cover 57 having a light-transmitting portion 57C through which light emitted from the LED chip 52 of the chip-on-board light-emitting diode 50 passes. The heat dissipation member may include the light cover 57.

[0175] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently dissipated through the light cover 57.

[0176] In this embodiment, the substrate 51 may have an annular portion 51A, and the LED chip 52 may be disposed on the front surface of the annular portion 51A. The light cover 57 may have an outer cylinder portion 57A disposed radially outward from the annular portion 51A, and an inner cylinder portion 57B disposed radially inward from the annular portion 51A. The light transmitting portion 57C may be disposed so as to connect the front end of the outer cylinder portion 57A to the front end of the inner cylinder portion 57B. The substrate 51 may be in contact with at least one of the outer cylinder portion 57A and the inner cylinder portion 57B while being spaced apart from the light transmitting portion 57C.

[0177] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 .

[0178] In this embodiment, the substrate 51 of the chip-on-board light-emitting diode 50 may be fixed to the heat dissipation member via an adhesive 59. Heat from the chip-on-board light-emitting diode 50 may be transferred to the heat dissipation member via the adhesive 59.

[0179] In the above configuration, the heat from the chip-on-board light-emitting diode 50 is efficiently transferred to the heat dissipation member via the adhesive 59 .

[0180] In the present embodiment, the impact tool 1 may include a light cover 57 having a light-transmitting portion 57C through which light emitted from the LED chip 52 of the chip-on-board light-emitting diode 50 passes. The heat dissipation member may include the light cover 57.

[0181] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 via the adhesive 59 .

[0182] In this embodiment, the substrate 51 may have an annular portion 51A, and the LED chip 52 may be disposed on the front surface of the annular portion 51A. The light cover 57 may have an outer cylinder portion 57A disposed radially outward from the annular portion 51A, and an inner cylinder portion 57B disposed radially inward from the annular portion 51A. The light transmitting portion 57C may be disposed so as to connect the front end of the outer cylinder portion 57A to the front end of the inner cylinder portion 57B. The substrate 51 may be fixed to the inner cylinder portion 57B via an adhesive 59.

[0183] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 via the adhesive 59 .

[0184] [Second embodiment] A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0185] <Power tools> Fig. 15 is a cross-sectional view showing a portion of a power tool 1B according to this embodiment. The power tool 1B is an impact tool 1B. In the above-described embodiment, the substrate 51 and the hammer case 4 are connected via the heat conductive sheet 60. In this embodiment, as shown in Fig. 15, the heat conductive sheet 60 is omitted, and the substrate 51 and the hammer case 4 are separated from each other.

[0186] In this embodiment, the heat dissipation member includes a light cover 57. The light cover 57 is in contact with the substrate 51. The substrate 51 is in contact with at least one of the outer cylinder portion 57A and the inner cylinder portion 57B while being spaced apart from the light-transmitting portion 57C. Heat from the chip-on-board light-emitting diodes 50 is transferred to the light cover 57. The heat from the chip-on-board light-emitting diodes 50 transferred to the light cover 57 is dissipated into the atmospheric space surrounding the light cover 57. This prevents the chip-on-board light-emitting diodes 50 from excessively increasing in temperature.

[0187] Similar to the above-described embodiment, the substrate 51 of the chip-on-board light-emitting diode 50 is fixed to the light cover 57 via an adhesive 59. Heat from the chip-on-board light-emitting diode 50 may be transferred to the light cover 57 via the adhesive 59.

[0188] <Effects> As described above, in this embodiment, the substrate 51 is separated from the hammer case 4 and the case cover 5. The heat dissipation member may include the light cover 57.

[0189] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently dissipated through the light cover 57.

[0190] In this embodiment, the substrate 51 may have an annular portion 51A, and the LED chip 52 may be disposed on the front surface of the annular portion 51A. The light cover 57 may have an outer cylinder portion 57A disposed radially outward from the annular portion 51A, and an inner cylinder portion 57B disposed radially inward from the annular portion 51A. The light transmitting portion 57C may be disposed so as to connect the front end of the outer cylinder portion 57A to the front end of the inner cylinder portion 57B. The substrate 51 may be in contact with at least one of the outer cylinder portion 57A and the inner cylinder portion 57B while being spaced apart from the light transmitting portion 57C.

[0191] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 .

[0192] In this embodiment, the substrate 51 of the chip-on-board light-emitting diode 50 may be fixed to the light cover 57 via an adhesive 59. Heat from the chip-on-board light-emitting diode 50 may be transferred to the light cover 57 via the adhesive 59.

[0193] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 via the adhesive 59 .

[0194] In this embodiment, the substrate 51 may have an annular portion 51A, and the LED chip 52 may be disposed on the front surface of the annular portion 51A. The light cover 57 may have an outer cylinder portion 57A disposed radially outward from the annular portion 51A, and an inner cylinder portion 57B disposed radially inward from the annular portion 51A. The light transmitting portion 57C may be disposed so as to connect the front end of the outer cylinder portion 57A to the front end of the inner cylinder portion 57B. The substrate 51 may be fixed to the inner cylinder portion 57B via an adhesive 59.

[0195] In the above configuration, the heat of the chip-on-board light-emitting diode 50 is efficiently transferred to the light cover 57 via the adhesive 59 .

[0196] [Third embodiment] A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of these components will be simplified or omitted.

[0197] <Power tools> Fig. 16 is a cross-sectional view showing a part of the power tool 1C according to this embodiment.Fig. 17 is an exploded perspective view of the upper part of the power tool 1C according to this embodiment, seen from the front.

[0198] In this embodiment, the impact tool 1C includes a heat sink 61 connected to the chip-on-board light-emitting diode 50. The heat sink 61 is disposed so as to contact the rear surface of the substrate 51.

[0199] The heat sink 61 is annular. The heat sink 61 is in the form of a thin plate. The heat sink 61 is made of metal. Examples of metals that form the heat sink 61 include aluminum and magnesium. The heat sink 61 has a higher thermal conductivity than the light cover 57.

[0200] The heat sink 61 has an annular portion 61A that contacts the rear surface of the annular portion 51A of the substrate 51, and a protruding portion 61B that contacts the rear surface of the support portion 51B of the substrate 51. The protruding portion 61B protrudes downward from the lower portion of the annular portion 61A.

[0201] The heat sink 61 faces both the hammer case 4 and the case cover 5 across a gap. The heat sink 61 faces the annular portion 4C of the hammer case 4 across a gap. The heat sink 61 faces the front end of the case cover 5 across a gap. In other words, the rear surface of the heat sink 61 is separated from both the hammer case 4 and the case cover 5. The rear surface of the heat sink 61 is in contact with the atmosphere.

[0202] The heat of the chip-on-board light-emitting diode 50 is transferred to the heat sink 61. The heat of the chip-on-board light-emitting diode 50 transferred to the heat sink 61 is dissipated into the air space around the heat sink 61. This prevents the temperature of the chip-on-board light-emitting diode 50 from rising excessively.

[0203] <Effects> As described above, in this embodiment, the heat dissipation member is the heat sink 61 that contacts the substrate 51 of the chip-on-board light-emitting diode 50.

[0204] In the above configuration, the heat from the chip-on-board light-emitting diode 50 is efficiently transferred to the heat sink 61 .

[0205] In this embodiment, the LED chip 52 of the chip-on-board light-emitting diode 50 may be disposed on the front surface of the substrate 51. The heat sink 61 may contact the rear surface of the substrate 51.

[0206] In the above configuration, the heat generated by the chip-on-board light-emitting diode 50 is efficiently dissipated through the heat sink 61 .

[0207] In this embodiment, the hammer case 4 may include a rear cylindrical portion 4A that houses the reduction mechanism 7, a front cylindrical portion 4B that holds a bearing that supports the anvil 10, and an annular portion 4C that connects the front end of the rear cylindrical portion 4A to the rear end of the front cylindrical portion 4B. The chip-on-board light-emitting diode 50 may be disposed around the front cylindrical portion 4B. The heat sink 61 may face the annular portion 4C with a gap therebetween.

[0208] In the above configuration, the heat from the chip-on-board light-emitting diode 50 is efficiently dissipated into the atmosphere via the heat sink 61 .

[0209] In this embodiment, the impact tool 1C may include a case cover 5 that covers the surface of the rear cylindrical portion 4A. The heat sink 61 may face the case cover 5 with a gap therebetween.

[0210] In the above configuration, the heat from the chip-on-board light-emitting diode 50 is efficiently dissipated into the atmosphere via the heat sink 61 .

[0211] [Fourth embodiment] A fourth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description of these components will be simplified or omitted.

[0212] <Power tools> Figure 18 is a front perspective view of a power tool 1D according to this embodiment. Figure 19 is a cross-sectional view of the power tool 1D according to this embodiment. In this embodiment, the power tool 1D is an angle drill, which is a type of electric power tool. In the following description, the power tool 1D will be referred to as an angle drill 1D where appropriate.

[0213] The angle drill 1D includes a motor housing 102, a handle housing 103, a gear case 104, a cover 105, a front grip 101, a battery mounting section 113, a controller 117, a main switch 116, a trigger lever 114, a forward / reverse rotation switch lever 115, a motor 106, a bearing box 124, a fan 112, a reduction mechanism 107, a spindle 108, and a drill chuck 111.

[0214] The motor housing 102 accommodates the motor 106. The handle housing 103 is disposed rearward of the motor housing 102. The front portion of the handle housing 103 is connected to the rear portion of the motor housing 102. The handle housing 103 has a loop shape that is long in the front-to-rear direction. The handle housing 103 has a front portion 103A that is connected to the rear portion of the motor housing 102, a grip portion 122 that extends rearward from the upper portion of the front portion 103A, a controller accommodating portion 103B that extends rearward from the lower portion of the front portion 103A, and a battery holding portion 123 that connects the rear end of the grip portion 122 to the rear end of the controller accommodating portion 103B. The grip portion 122 is disposed above the controller accommodating portion 103B. The grip portion 122 is disposed on the rear side of the motor housing 102. The operator can hold the grip portion 122 with their hand.

[0215] The gear case 104 houses the reduction mechanism 107. The gear case 104 is cylindrical. The gear case 104 is disposed on the front side of the motor housing 102. The rear part of the gear case 104 is connected to the front part of the motor housing 102. The gear case 104 is made of aluminum. At least a part of the surface of the gear case 104 is covered with a cover 105. In this embodiment, the cover 105 has a two-layer structure of synthetic resin and elastomer.

[0216] The front grip 101 is fixed to the gear case 104. An operator can hold the front grip 101.

[0217] The battery attachment section 113 is disposed at the rear of the handle housing 103. A battery pack 125 is attached to the battery attachment section 113. The battery attachment section 113 is provided in the battery holding section 123 of the handle housing 103. In this embodiment, two battery attachment sections 113 are provided in the vertical direction. A battery pack 125 is attached to each of the two battery attachment sections 113, so that two battery packs 125 are arranged in the vertical direction. The battery packs 125 are detachable from the battery attachment sections 113. When attached to the battery attachment sections 113, the battery packs 125 can supply power to the angle drill 1D.

[0218] The controller 117 outputs a control signal for controlling the angle drill 1D. The controller accommodating portion 103B has an internal space capable of accommodating the controller 117. The controller 117 is accommodated in the controller accommodating portion 103B.

[0219] The main switch 116 is operated by an operator to start the angle drill 1D. The main switch 116 is provided on the upper part of the front part 103A. When the main switch 116 is operated, power is supplied from the battery pack 125 to the controller 117, and the angle drill 1D starts. When the main switch 116 is operated, the angle drill 1D is switched between starting and stopping.

[0220] The trigger lever 114 is operated by an operator to start the motor 106. The trigger lever 114 is provided on the grip portion 122. The trigger lever 114 protrudes downward from the lower front portion of the grip portion 122. While holding the grip portion 122 with one of the hands, the operator can operate the trigger lever 114 with a finger so that the trigger lever 114 moves upward. When the angle drill 1D is started, pulling the trigger lever 114 upward supplies power from the battery pack 125 to the motor 106, starting the motor 106. Switching between operating and releasing the trigger lever 114 switches between driving and stopping the motor 106.

[0221] The forward / reverse switching lever 115 is operated by an operator to switch the rotation direction of the motor 106. The forward / reverse switching lever 115 is provided on the front portion 103A. By operating the forward / reverse switching lever 115 left or right, the rotation direction of the motor 106 is switched between the forward direction and the reverse direction. By switching the rotation direction of the motor 106, the rotation direction of the spindle 108 is switched between the forward direction and the reverse direction.

[0222] The motor 106 generates a rotational force for rotating the spindle 108. The motor 106 is driven by power supplied from a battery pack 125. The motor 106 is an inner rotor type brushless motor. The motor 106 has a cylindrical stator 126 and a rotor 127 disposed inside the stator 126. A rotation axis AX of the rotor 127 extends in the front-rear direction. The rotor 127 has a rotor shaft 133 and a cylindrical rotor core 132 disposed around the rotor shaft 133. A rear portion of the rotor shaft 133 is rotatably supported by a rotor bearing 139. A front portion of the rotor shaft 133 is rotatably supported by a rotor bearing 140.

[0223] The bearing box 124 holds the rotor bearing 140. The bearing box 124 is fixed to the rear end of the gear case 104.

[0224] The fan 112 rotates due to the rotational force of the motor 106. The fan 112 is attached to a rotor shaft 133 between a rotor bearing 140 and a stator 126. An exhaust port 120 is provided in the motor housing 102. The exhaust port 120 is located at a portion of the periphery of the fan 112. As the rotor shaft 133 rotates and the fan 112 rotates, air in the interior space of the motor housing 102 is exhausted to the exterior space of the motor housing 102 through the exhaust port 120. The air exhausted to the exterior space of the motor housing 102 through the exhaust port 120 passes between the gear case 104 and the cover 105, and then is exhausted from between the gear case 104 and the cover 105 to cool the light unit 118.

[0225] A pinion gear 141 is provided at the front end of the rotor shaft 133. The pinion gear 141 is disposed in the internal space of the gear case 104. The rotor shaft 133 is connected to the reduction mechanism 107 via the pinion gear 141.

[0226] The reduction gear mechanism 107 transmits the rotational force generated by the motor 106 to the spindle 108. The reduction gear mechanism 107 transmits the rotational force from the rotor shaft 133 to the spindle 108. The reduction gear mechanism 107 includes a plurality of gears. The reduction gear mechanism 107 has a first planetary gear mechanism 107A, a second planetary gear mechanism 107B, a first intermediate shaft 107C, and a second intermediate shaft 107D.

[0227] The first planetary gear mechanism 107A is disposed in front of the rotor shaft 133. The first intermediate shaft 107C is disposed in front of the first planetary gear mechanism 107A. The second planetary gear mechanism 107B is disposed in front of the first intermediate shaft 107C. The second intermediate shaft 107D is disposed in front of the second planetary gear mechanism 107B. The second intermediate shaft 107D is rotatably supported by a bearing 144.

[0228] The spindle 108 is an output shaft of the angle drill 1D that rotates due to the rotational force of the motor 106. The spindle 108 rotates around a rotation axis BX. The rotation axis AX of the motor 106 and the rotation axis BX of the spindle 108 are perpendicular to each other. The spindle 108 is rotatably supported by a needle bearing 145 and a ball bearing 146. The needle bearing 145 rotatably supports the upper end of the spindle 108. The ball bearing 146 rotatably supports the lower end of the spindle 108. A bevel gear 147 is provided at the upper end of the spindle 108. The bevel gear 147 meshes with the bevel gear 148 of the second intermediate shaft 107D. The diameter of the bevel gear 147 is larger than the diameter of the bevel gear 148. The number of teeth of the bevel gear 147 is greater than the number of teeth of the bevel gear 148.

[0229] The drill chuck 111 is attached to the lower end of the spindle 108. A drill bit is attached to the drill chuck 111. The drill chuck 111 is rotatable with the drill bit attached.

[0230] The light unit 118 is disposed around the spindle 108 and the drill chuck 111. As in the above-described embodiment, the light unit 118 includes a chip-on-board light-emitting diode 50. The light unit 118 is fixed to the gear case 104. A substrate 51 of the chip-on-board light-emitting diode 50 is fixed to the gear case 104. The light unit 118 is supplied with power from the controller 117. The driving voltage of the light unit 118 is 5 V. A power supply cable connecting the chip-on-board light-emitting diode 50 and the controller 117 passes between the gear case 104 and the cover 105.

[0231] The luminous flux of the light unit 118 is not less than 50 lumens and not more than 200 lumens. The luminous flux of the light unit 118 may be not less than 80 lumens and not more than 150 lumens, or may be not less than 100 lumens and not more than 130 lumens.

[0232] In this embodiment, the heat dissipation device that dissipates heat from the chip-on-board light-emitting diodes 50 includes a fan 112. As the fan 112 rotates, air is supplied from the fan 112 to a light unit 118 that includes the chip-on-board light-emitting diodes 50. As shown by arrow FW in FIG. 19 , the air from the fan 112 is discharged toward the light unit 118 through the space between the gear case 104 and the cover 105. In this embodiment, a flow path is formed in a part of the gear case 104.

[0233] <Effects> As described above, the angle drill 1D may be provided with the fan 112 that rotates by the rotational force of the motor 6. The heat dissipation device may include the fan 112. Air may be supplied to the chip-on-board light-emitting diodes 50 from the fan 112.

[0234] In the above configuration, the air supplied by the fan 112 dissipates the heat from the chip-on-board light-emitting diodes 50 .

[0235] [Fifth embodiment] A fifth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description of these components will be simplified or omitted.

[0236] <Light unit> Fig. 20 is a view of the light unit 18 according to this embodiment as seen from the front. Fig. 21 is a longitudinal cross-sectional view showing the light unit 18 according to this embodiment. Fig. 22 is a transverse cross-sectional view showing the light unit 18 according to this embodiment. Fig. 21 is a cross-sectional view taken along line AA in Fig. 20, which is a cross-sectional view parallel to the rotation axis AX of the anvil 10 and passes through the rotation axis AX. Fig. 22 is a cross-sectional view taken along line BB in Fig. 20, which is a cross-sectional view parallel to the rotation axis AX of the anvil 10 and passes through the rotation axis AX.

[0237] Similar to the above-described embodiment, the light unit 18 has a chip-on-board light-emitting diode 50 and a light cover 57 (optical member). The light cover 57 is translucent and light white. The chip-on-board light-emitting diode 50 has a substrate 51 and a plurality of LED chips 52 (light-emitting elements). The chip-on-board light-emitting diode 50 is arranged around the anvil 10. Similar to the above-described embodiment, the substrate 51 of the chip-on-board light-emitting diode 50 is ring-shaped. The light cover 57 is arranged around the anvil 10. Note that the anvil 10 is not shown in Figures 20, 21, and 22.

[0238] The light cover 57 has a light-transmitting portion 57C through which light emitted from the LED chip 52 passes. The light-transmitting portion 57C functions as a light refracting portion that refracts light emitted from the chip-on-board light-emitting diode 50. The light-transmitting portion 57C is ring-shaped. The light-transmitting portion 57C has an incident surface 57E onto which light emitted from the LED chip 52 of the chip-on-board light-emitting diode 50 enters and an exit surface 57F from which light transmitted through the light-transmitting portion 57C exits. In at least one cross section parallel to and passing through the rotation axis AX, the shape of the light-transmitting portion 57C is line-symmetrical with respect to the rotation axis AX. At least the incident surface 57E and the exit surface 57F are line-symmetrical with respect to the rotation axis AX. In this embodiment, the incident surface 57E is inclined rearward toward the radially outward direction. The exit surface 57F is perpendicular to an axis parallel to the rotation axis AX.

[0239] In this embodiment, the shape of the light transmitting portion 57C is line-symmetric with respect to the rotation axis AX in all cross sections that are parallel to the rotation axis AX and pass through the rotation axis AX.

[0240] <Effects> As described above, in at least one cross section that is parallel to the rotation axis AX of the anvil 10 and passes through the rotation axis AX, the shape of the light transmitting portion 57C is line-symmetrical with respect to the rotation axis AX.

[0241] In the above configuration, the chip-on-board light-emitting diode 50 and the light-transmitting portion 57C of the light cover 57 are each ring-shaped and arranged around the anvil 10, and since the light-transmitting portion 57C is line-symmetric, light is emitted in a ring shape from the light-transmitting portion 57C. This prevents shadows from being cast on the work object.

[0242] The cross-sectional shape of the entire light cover 57 does not need to be line-symmetrical about the rotation axis AX, but it is sufficient that at least the entrance surface 57E and the exit surface 57F are each line-symmetrical about the rotation axis AX.

[0243] In this embodiment, incident surface 57E is inclined radially outward and rearward. Exit surface 57F is perpendicular to an axis parallel to rotation axis AX. With the above configuration, light is appropriately spread from light transmitting portion 57C, brightly illuminating the work object.

[0244] In this embodiment, in all cross sections that are parallel to the rotation axis AX and pass through the rotation axis AX, the shape of the light transmitting portion 57C is line-symmetric with respect to the rotation axis AX.

[0245] In the above configuration, the shape of the light-transmitting portion 57C is line-symmetrical with respect to the rotation axis AX in all cross sections that are parallel to the rotation axis AX and pass through the rotation axis AX, so that light is emitted in a ring shape from the light-transmitting portion 57C. The chip-on-board light-emitting diodes 50 brightly illuminate the work object.

[0246] [Other embodiments] In the first, second and third embodiments described above, the impact tool (1, etc.) is an impact driver. The impact tool (1, etc.) may be an impact wrench.

[0247] In the above-described embodiment, the power source for the power tool (1, etc.) does not have to be a battery pack (25, etc.) and may be a commercial power source (AC power source).

[0248] In the above-described embodiment, the power tool (1, etc.) is an electric tool powered by an electric motor. The power tool may also be a pneumatic tool powered by an air motor. The power source of the power tool is not limited to an electric motor or an air motor, and may be another power source. The power source of the power tool may be, for example, a hydraulic motor or a motor driven by an engine. [Explanation of symbols]

[0249] 1...Power tool (impact tool), 1B...Power tool (impact tool), 1C...Power tool (impact tool), 1D...Power tool (angle drill), 2...Housing, 2L...Left housing, 2R...Right housing, 2S...Screw, 3...Rear cover, 4...Hammer case, 4A...Rear cylinder part, 4B...Front cylinder part, 4C...Annular part, 4D...Convex part, 4E...Rear surface, 4F...Slope, 5...Case cover, 6...Motor, 7...Reduction mechanism, 8...Spindle, 8A...Flange part, 8B...Spindle shaft part, 8C...Annular part, 8D...Spindle groove, 9...Striking mechanism, 10...Anvil (output shaft (g), 10A...tool hole, 10B...convex portion, 10C...anvil shaft portion, 10D...anvil protrusion portion, 11...tool holding mechanism, 12...fan, 12A...bush, 13...battery mounting portion, 14...trigger lever, 15...forward / reverse switching lever, 16...hand mode switching button, 17...controller, 18...light unit, 19...air intake, 20...exhaust port, 21...motor housing portion, 22...grip portion, 23...battery holding portion, 24...bearing box, 25...battery pack, 26...stator, 27...rotor, 28...stator core, 29...front insulator, 29S...screw, 30... rear insulator, 31... coil, 32... rotor core portion, 33... rotor shaft portion, 34... rotor magnet, 35... sensor magnet, 37... sensor board, 38... fusing terminal, 39... rotor bearing, 40... rotor bearing, 41... pinion gear, 42... planetary gear, 42P... pin, 43... internal gear, 44... spindle bearing, 45... washer, 46... anvil bearing, 47... hammer, 47A... hammer groove, 47C... recess, 48... ball, 49... coil spring, 50... chip-on-board light-emitting diode, 51... board, 51A ... annular portion, 51B... supporting portion, 52... LED chip, 53... gold wire, 54... bank, 55... phosphor, 56... electrode, 56A... positive electrode, 56B... negative electrode, 57... light cover, 57A... outer cylinder portion, 57B... inner cylinder portion, 57C... light transmitting portion, 57D... supporting portion, 57E... incident surface, 57F... exit surface, 57G... recess, 57H... notch, 57J... support convex portion, 57K... recess, 57M... rear slide portion, 57N... front slide portion, 57P... front surface, 57Q... inclined surface, 58... lead wire, 59... adhesive, 60... thermal conductive material (thermal conductive sheet), 60A... annular portion, 60B... convex portion, 61... heat sink,61A... annular portion, 61B... convex portion, 101... front grip, 102... motor housing, 103... handle housing, 103A... front portion, 103B... controller accommodating portion, 104... gear case, 105... cover, 106... motor, 107... reduction mechanism, 107A... first planetary gear mechanism, 107B... second planetary gear mechanism, 107C... first intermediate shaft, 107D... second intermediate shaft, 108... spindle (output shaft), 111... drill chuck, 113... battery mounting portion, 114... trigger lever, 115... forward / reverse rotation switching lever, 116...main switch, 117...controller, 112...fan, 118...light unit, 120...exhaust port, 122...grip portion, 123...battery holding portion, 124...bearing box, 125...battery pack, 126...stator, 127...rotor, 132...rotor core, 133...rotor shaft, 139...rotor bearing, 140...rotor bearing, 141...pinion gear, 144...bearing, 145...needle bearing, 146...ball bearing, 147...bevel gear, 148...bevel gear, AX...rotating shaft.

Claims

1. A motor; an output shaft that rotates by the torque of the motor; a chip-on-board light emitting diode disposed around the output shaft; a white translucent optical member having a light refracting portion that refracts light emitted from the chip-on-board light emitting diode; a shape of the light refracting portion in at least one cross section that is parallel to a rotation axis of the output shaft and passes through the rotation axis is line-symmetric with respect to the rotation axis; Power tools.

2. the light refraction unit has an incident surface onto which light emitted from the chip-on-board light emitting diode is incident and an exit surface from which light transmitted through the light refraction unit is exited, the entrance surface and the exit surface are each symmetrical about the rotation axis; 2. The power tool of claim 1.

3. The entrance surface is inclined rearward toward the radially outward direction, the exit surface is perpendicular to an axis parallel to the rotation axis; 3. The power tool of claim 2.

4. In all cross sections passing through the rotation axis, the shape of the light refracting portion is line-symmetric with respect to the rotation axis.

2. The power tool of claim 1.

5. A motor; an output shaft that rotates by the torque of the motor; a chip-on-board light emitting diode disposed around the output shaft; a heat dissipation device for dissipating heat from the chip-on-board light emitting diode; Power tools.

6. the heat dissipation device includes a heat dissipation member to which heat from the chip-on-board light emitting diode is transferred; 6. The power tool of claim 5.

7. a reduction mechanism that transmits the rotational force of the motor to the output shaft; a gear case that houses the reduction mechanism, The heat dissipation member includes the gear case.

7. The power tool of claim 6.

8. a thermally conductive material that transfers heat from the chip-on-board light-emitting diode to the gear case; 8. The power tool of claim 7.

9. the thermally conductive material contacts each of the substrate of the chip-on-board light-emitting diode and the gear case; 9. The power tool of claim 8.

10. The thermally conductive material is in a sheet form.

10. The power tool of claim 9.

11. the gear case includes a rear-side cylindrical portion that houses the reduction mechanism, a front-side cylindrical portion that holds a bearing that supports the output shaft, and an annular portion that connects a front end portion of the rear-side cylindrical portion and a rear end portion of the front-side cylindrical portion, the chip-on-board light-emitting diodes are disposed around the front barrel portion; the thermally conductive material contacts each of the substrate and the annular portion; 10. The power tool of claim 9.

12. a case cover that covers a surface of the rear tube portion, the heat dissipation member includes the case cover, the thermally conductive material is in contact with the case cover; 12. The power tool of claim 11.

13. the heat dissipation member is in contact with the substrate of the chip-on-board light-emitting diode; 7. The power tool of claim 6.

14. The LED chip of the chip-on-board light emitting diode is disposed on the front surface of the substrate; the heat dissipation member includes a heat sink in contact with the rear surface of the substrate; 14. The power tool of claim 13.

15. a reduction mechanism that transmits the rotational force of the motor to the output shaft; a gear case that houses the reduction mechanism, the gear case includes a rear-side cylindrical portion that houses the reduction mechanism, a front-side cylindrical portion that holds a bearing that supports the output shaft, and an annular portion that connects a front end portion of the rear-side cylindrical portion and a rear end portion of the front-side cylindrical portion, the chip-on-board light-emitting diodes are disposed around the front barrel portion; the heat sink faces the annular portion with a gap therebetween; 15. The power tool of claim 14.

16. a case cover that covers a surface of the rear tube portion, The heat sink faces the case cover with a gap therebetween.

16. The power tool of claim 15.

17. a light cover having a light transmitting portion through which light emitted from the LED chip of the chip-on-board light emitting diode passes; The heat dissipation member includes the light cover.

14. The power tool of claim 13.

18. the substrate has an annular portion, the LED chip is disposed on the front surface of the annular portion; the light cover has an outer cylindrical portion disposed radially outward from the annular portion and an inner cylindrical portion disposed radially inward from the annular portion, the light transmitting portion is arranged to connect a front end portion of the outer cylindrical portion and a front end portion of the inner cylindrical portion, the substrate is in contact with at least one of the outer cylindrical portion and the inner cylindrical portion while being spaced apart from the light transmitting portion; 18. The power tool of claim 17.

19. a substrate of the chip-on-board light-emitting diode is fixed to the heat dissipation member via an adhesive; Heat from the chip-on-board light-emitting diode is transferred to the heat dissipation member via the adhesive.

7. The power tool of claim 6.

20. a light cover having a light transmitting portion through which light emitted from the LED chip of the chip-on-board light emitting diode passes; The heat dissipation member includes the light cover.

20. The power tool of claim 19.

21. the substrate has an annular portion, the LED chip is disposed on the front surface of the annular portion; the light cover has an outer cylindrical portion disposed radially outward from the annular portion and an inner cylindrical portion disposed radially inward from the annular portion, the light transmitting portion is arranged to connect a front end portion of the outer cylindrical portion and a front end portion of the inner cylindrical portion, the substrate is fixed to the inner cylindrical portion via the adhesive; 21. The power tool of claim 20.

22. a reduction mechanism that transmits the rotational force of the motor to the output shaft; a gear case that houses the reduction mechanism, the gear case includes a rear-side cylindrical portion that houses the reduction mechanism, a front-side cylindrical portion that holds a bearing that supports the output shaft, and an annular portion that connects a front end portion of the rear-side cylindrical portion and a rear end portion of the front-side cylindrical portion, the inner cylindrical portion is disposed around the front cylindrical portion and fixed to the front cylindrical portion; 22. A power tool according to claim 18 or claim 21.

23. the output shaft includes an anvil; a striking mechanism to which the rotational force of the motor is transmitted via the reduction mechanism and which strikes the anvil in the rotational direction; The gear case is a hammer case that accommodates the reduction mechanism and the impact mechanism. A power tool according to claim 11 or claim 15.

24. a fan that rotates by the rotational force of the motor, the heat dissipation device includes a fan; Air is supplied from the fan to the chip-on-board light-emitting diodes.

7. The power tool of claim 6.

Images