Electric work machine

Abstract

To prevent deterioration of light emission performance of a light unit even if an impact is applied to the light unit.SOLUTION: An electric work machine comprises: a motor; a housing with a motor housing portion housing the motor and a grip portion projecting downward from the motor housing portion; an output unit disposed in front of the motor and configured to be operated by a rotational force of the motor; a substrate disposed over an upper side, a left side, and a right side of the output unit; and a plurality of light emitting elements mounted on a front surface of the substrate at intervals in a circumferential direction of the output unit. A light emitting element closest to a vertex portion of the substrate immediately above the output unit is disposed at a position shifted by a predetermined angle in a circumferential direction from the vertex portion.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The technology disclosed in this specification relates to electric power tools.

Background Art

[0002] In the technical field related to electric power tools, a lighting system for power tools as disclosed in Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the lighting system for power tools has a chip on board light emitting diode (COB LED) as a light unit. When a light unit is provided in an electric power tool, for example, if an impact is applied to the light unit due to the fall of the electric power tool, the light emitting performance of the light unit may deteriorate.

[0005] The technology disclosed in this specification aims to suppress a decrease in the light emitting performance of the light unit even when an impact is applied to the light unit.

Means for Solving the Problems

[0006] This specification discloses an electric work machine. The electric work machine may include a motor, a housing having a motor housing portion for housing the motor and a grip portion protruding downward from the motor housing portion, an output portion positioned in front of the motor and operated by the rotational force of the motor, a substrate positioned above, to the left of, and to the right of the output portion, and a plurality of light-emitting elements mounted on the front surface of the substrate at intervals in the circumferential direction of the output portion. The light-emitting element closest to the apex of the substrate directly above the output portion may be positioned at a predetermined angle shifted circumferentially from the apex. [Effects of the Invention]

[0007] With the above configuration, even if the light unit is subjected to an impact, the deterioration of the light unit's luminescence performance is suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a front perspective view showing the electric work machine according to this embodiment. [Figure 2] Figure 2 is a side view showing the upper part of the electric work machine according to this embodiment. [Figure 3] Figure 3 is a longitudinal cross-sectional view showing the upper part of the electric work machine according to this embodiment. [Figure 4] Figure 4 is a cross-sectional view showing the upper part of the electric work machine according to this embodiment. [Figure 5] Figure 5 is a cross-sectional view showing a part of the light unit according to this embodiment. [Figure 6] Figure 6 is an exploded perspective view from the front showing the upper part of the electric work machine according to this embodiment. [Figure 7] Figure 7 is a front perspective view showing the light unit according to this embodiment. [Figure 8] Figure 8 is a rear perspective view showing the light unit according to this embodiment. [Figure 9] Figure 9 is an exploded perspective view from the front showing the light unit according to this embodiment. [Figure 10]Figure 10 is an exploded perspective view from the rear showing the light unit according to this embodiment. [Figure 11] Figure 11 is a view of the chip-on-board light-emitting diode according to this embodiment, seen from the front. [Figure 12] Figure 12 is a view of the substrate according to this embodiment, seen from the front. [Figure 13] Figure 13 is a schematic diagram showing the state in which the electric work machine according to this embodiment has fallen. [Figure 14] Figure 14 is a front view of the substrate of a chip-on-board light-emitting diode according to another embodiment. [Figure 15] Figure 15 is a front view of the substrate of a chip-on-board light-emitting diode according to another embodiment. [Figure 16] Figure 16 is a front view of the substrate of a chip-on-board light-emitting diode according to another embodiment. [Figure 17] Figure 17 is a front view of the substrate of a chip-on-board light-emitting diode according to another embodiment. [Figure 18] Figure 18 is a front perspective view showing an electric work machine according to another embodiment. [Modes for carrying out the invention]

[0009] In one or more embodiments, the electric work machine may include a motor, a housing having a motor housing portion for housing the motor and a grip portion protruding downward from the motor housing portion, an output portion positioned in front of the motor and operated by the rotational force of the motor, a substrate positioned above, to the left of, and to the right of the output portion, and a plurality of light-emitting elements mounted on the front surface of the substrate at intervals in the circumferential direction of the output portion. The light-emitting element closest to the apex of the substrate directly above the output portion may be positioned at a predetermined angle shifted circumferentially from the apex.

[0010] In the above configuration, when the light unit has a substrate and light-emitting elements, even if an impact is applied to the apex portion of the substrate due to, for example, the dropping of a power-operated work machine, no light-emitting elements are arranged at the apex portion of the substrate. Therefore, breakage of the light-emitting elements or separation from the substrate is suppressed. As a result, non-lighting of the light-emitting elements is suppressed. Thus, a decrease in the light-emitting performance of the light unit is suppressed.

[0011] In one or more embodiments, the plurality of light-emitting elements may be arranged at symmetric positions with respect to a straight line extending in the vertical direction through the central axis and the apex portion of the output portion.

[0012] In the above configuration, the work target of the power-operated work machine is properly illuminated by the plurality of light-emitting elements.

[0013] In one or more embodiments, the substrate may have an annular portion arranged around the output portion. The plurality of light-emitting elements may be mounted on the front surface of the annular portion.

[0014] In the above configuration, since the plurality of light-emitting elements are mounted on the front surface of the annular portion of the substrate, the work target of the power-operated work machine is properly illuminated.

[0015] In one or more embodiments, the plurality of light-emitting elements may be arranged at equal intervals in the circumferential direction on the front surface of the annular portion.

[0016] In the above configuration, since the plurality of light-emitting elements are mounted at equal intervals on the front surface of the annular portion of the substrate, the work target of the power-operated work machine is properly illuminated.

[0017] In one or more embodiments, the light unit may include banks arranged respectively radially inward and radially outward of the light-emitting elements on the front surface of the annular portion, a phosphor arranged to cover the light-emitting elements inside the banks, and an optical member having an outer cylinder portion arranged radially outward of the annular portion and a light-transmitting portion arranged in front of the light-emitting elements through which light emitted from the light-emitting elements passes.

[0018] In the above configuration, light emitted from the light-emitting element is projected forward of the light unit via the phosphor and light-transmitting section. For example, if an electric work machine falls and an impact is applied to the top of the substrate, the impact may be applied to the bank via the outer cylinder. Even if the bank is deformed or damaged due to the impact, since there is no light-emitting element located at the top of the substrate, damage to the light-emitting element or separation from the substrate is suppressed.

[0019] In one or more embodiments, the substrate may have a projection that protrudes upward from the upper part of the annular portion.

[0020] In the above configuration, for example, if an electric work machine falls, the protruding part mitigates the impact applied to the apex of the annular part. In other words, since the protruding part functions as an impact absorber, excessive impact on the light-emitting element is suppressed.

[0021] In one or more embodiments, the upper surface of the projection may be a flat surface extending in the left-right direction.

[0022] In the above configuration, the protruding portion functions properly as a shock-absorbing portion.

[0023] In one or more embodiments, the upper surface of the protrusion may be a curved surface in which the center of the upper surface in the left-right direction bulges upward.

[0024] In the above configuration, the protruding portion functions properly as a shock-absorbing portion.

[0025] In one or more embodiments, the light unit may include a positive electrode provided on the substrate to which a positive voltage is applied, and a negative electrode provided on the substrate to which a negative voltage is applied. Each of the multiple light-emitting elements may be connected in parallel to the positive electrode and the negative electrode.

[0026] In the above configuration, multiple light-emitting elements are connected in parallel, so even if, for example, one light-emitting element fails to light up, it is suppressed that other light-emitting elements will also fail to light up.

[0027] In one or more embodiments, the light unit may include power lines provided on a substrate and connected to each of a plurality of light-emitting elements, and resistors placed on the power lines.

[0028] In the above configuration, the voltage applied to the light-emitting element is adjusted by a resistor. The resistor, for example, equalizes the brightness of multiple light-emitting elements.

[0029] In one or more embodiments, the resistor may be positioned between a pair of adjacent light-emitting elements on the front surface of the substrate.

[0030] In the above configuration, the light-emitting element and the resistor are properly mounted on the front of the circuit board.

[0031] In one or more embodiments, the resistor may be located at the vertex.

[0032] In the above configuration, even if the top of the circuit board is subjected to impact, for example, by a fall of an electric work machine, the resistor is less likely to be damaged than the light-emitting element, thus suppressing a decrease in the light-emitting performance of the light unit.

[0033] In one or more embodiments, the substrate may have an annular portion arranged around the output section. The light-emitting elements and resistors may be arranged alternately, one by one, in the circumferential direction on the front surface of the annular portion.

[0034] In the above configuration, the light-emitting element and the resistor are properly mounted on the front of the annular section.

[0035] In one or more embodiments, the output section may include an anvil that is struck in the rotational direction by a hammer.

[0036] In the above configuration, the light unit is applied to the impact tool.

[0037] The embodiments will be described below with reference to the drawings. In the embodiments, the positional relationships of each part will be described using the terms left, right, front, rear, top, and bottom. These terms indicate relative positions or directions with respect to the center of the electric work machine.

[0038] [Electric work equipment] Figure 1 is a front perspective view showing the electric work machine 1 according to this embodiment. Figure 2 is a side view showing the top of the electric work machine 1 according to this embodiment. Figure 3 is a longitudinal cross-sectional view showing the top of the electric work machine 1 according to this embodiment. Figure 4 is a transverse cross-sectional view showing the top of the electric work machine 1 according to this embodiment.

[0039] In this embodiment, the electric work machine 1 is an electric tool having an electric motor 6 as a power source. The direction parallel to the rotation axis AX of the motor 6 is appropriately referred to as the axial direction, the direction that circles around the rotation axis AX is appropriately referred to as the circumferential direction or rotational direction, and the radial direction of the rotation axis AX is appropriately referred to as the radial direction. Furthermore, in the radial direction, the position close to or approaching the rotation axis AX is appropriately referred to as the radially inward direction, and the position far from or away from the rotation axis AX is appropriately referred to as the radially outward direction. In this embodiment, the rotation axis AX extends in the front-rear direction. One side in the axial direction is the front, and the other side in the axial direction is the rear.

[0040] In this embodiment, the electric work implement 1 is assumed to be an impact tool, which is a type of power tool. In the following description, the electric work implement 1 will be referred to as impact tool 1 as appropriate.

[0041] In this embodiment, the impact tool 1 is an impact driver, which is a type of screw tightening tool. The impact tool 1 comprises 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 section 13, a trigger lever 14, a forward / reverse switching lever 15, a hand-held mode switching button 16, and a light unit 18.

[0042] Housing 2 is made of synthetic resin. In this embodiment, housing 2 is made of nylon. 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 fastened together by a plurality of screws 2S. Housing 2 is composed of a pair of split housings.

[0043] The housing 2 includes a motor housing section 21, a grip section 22, and a battery holding section 23.

[0044] The motor housing 21 is cylindrical. The motor housing 21 houses the motor 6, a part of the bearing box 24, and the rear part of the hammer case 4.

[0045] The grip portion 22 protrudes downward from the motor housing portion 21. The trigger lever 14 is located on the upper part of the grip portion 22. The grip portion 22 is held by the operator.

[0046] The battery holder 23 is connected to the lower end of the grip portion 22. In both the front-to-back and left-to-right directions, the external dimensions of the battery holder 23 are larger than the external dimensions of the grip portion 22.

[0047] The rear cover 3 is made of synthetic resin. The rear cover 3 is positioned behind the motor housing 21. The rear cover 3 houses at least a portion of the fan 12. The fan 12 is positioned on the inner circumference side of the rear cover 3. The rear cover 3 is positioned to cover the opening at the rear end of the motor housing 21. The rear cover 3 is fixed to the rear end of the motor housing 21 by screws 3S.

[0048] The motor housing 21 has an air intake port 19. The rear cover 3 has an 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 into the external space of the housing 2 through the exhaust port 20.

[0049] The hammer case 4 functions as a gear case housing the reduction mechanism 7. The hammer case 4 houses the reduction mechanism 7, the spindle 8, the striking mechanism 9, and at least a portion of the anvil 10. The hammer case 4 is made of metal. In this embodiment, the hammer case 4 is made of aluminum. The hammer case 4 is cylindrical.

[0050] The hammer case 4 includes a rear cylindrical section 4A, a front cylindrical section 4B, and an annular section 4C. The front cylindrical section 4B is positioned forward of the rear cylindrical section 4A. The outer diameter of the rear cylindrical section 4A is larger than the outer diameter of the front cylindrical section 4B. The inner diameter of the rear cylindrical section 4A is larger than the inner diameter of the front cylindrical section 4B. The annular section 4C is positioned to connect the front end of the rear cylindrical section 4A and the rear end of the front cylindrical section 4B.

[0051] The hammer case 4 is connected to the front of the motor housing 21. The bearing box 24 is fixed to the rear of the rear cylindrical section 4A. At least a portion of the reduction mechanism 7 is located inside the bearing box 24. Screw threads are formed on the outer circumference of the bearing box 24. Screw grooves are formed on the inner circumference of the rear of the rear cylindrical section 4A. The bearing box 24 and the hammer case 4 are fixed together by the connection of the screw threads of the bearing box 24 and the screw grooves of the rear cylindrical section 4A. The hammer case 4 is sandwiched between the left housing 2L and the right housing 2R. A portion of the bearing box 24 and the rear of the rear cylindrical section 4A are housed in the motor housing 21. The bearing box 24 is fixed to both the motor housing 21 and the hammer case 4.

[0052] 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 cylindrical 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 operator.

[0053] Motor 6 is the power source for impact tool 1. Motor 6 generates rotational force. Motor 6 is an electric motor. Motor 6 is an inner rotor type brushless motor. Motor 6 has a stator 26 and a rotor 27. The stator 26 is supported by the motor housing 21. At least a portion of the rotor 27 is located inside the stator 26. The rotor 27 rotates relative to the stator 26. The rotor 27 rotates around a rotation axis AX that extends in the front-rear direction.

[0054] The stator 26 includes a stator core 28, a front insulator 29, a rear insulator 30, and a coil 31.

[0055] The stator core 28 is positioned radially outward from the rotor 27. The stator core 28 includes multiple laminated steel plates. The steel plates are metal plates mainly composed of iron. The stator core 28 is cylindrical. The stator core 28 has multiple teeth that support the coil 31.

[0056] The front insulator 29 is provided at the front of the stator core 28. The rear insulator 30 is provided at the rear of the stator core 28. Both the front insulator 29 and the rear insulator 30 are electrically insulating members made of synthetic resin. The front insulator 29 is positioned to cover a portion of the surface of the teeth. The rear insulator 30 is positioned to cover a portion of the surface of the teeth.

[0057] The coil 31 is mounted on the stator core 28 via a front insulator 29 and a 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 isolated by the front insulator 29 and the rear insulator 30. Multiple coils 31 are connected via a fusing terminal 38.

[0058] The rotor 27 rotates around the rotation axis AX. The rotor 27 has a rotor core 32, a rotor shaft 33, a rotor magnet 34, and a sensor magnet 35.

[0059] 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 integrated. The front portion of the rotor shaft portion 33 protrudes forward from the front end surface of the rotor core portion 32. The rear portion of the rotor shaft portion 33 protrudes rearward from the rear end surface of the rotor core portion 32.

[0060] The rotor magnet 34 is fixed to the rotor core 32. The rotor magnet 34 is cylindrical. The rotor magnet 34 is arranged around the rotor core 32.

[0061] The sensor magnet 35 is fixed to the rotor core 32. The sensor magnet 35 is annular in shape. The sensor magnet 35 is positioned on the front end surface of the rotor core 32 and the front end surface of the rotor magnet 34.

[0062] A sensor board 37 is attached to the front insulator 29. The sensor board 37 is fixed to the front insulator 29 by screws 29S. The sensor board 37 has an annular circuit board, a magnetic sensor 37A supported by the circuit board, and a resin molded body 37B covering the magnetic sensor 37A. At least a portion of the sensor board 37 faces the sensor magnet 35. The magnetic sensor 37A detects the rotational position of the rotor 27 by detecting the position of the sensor magnet 35.

[0063] The rear portion of the rotor shaft 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 in the rear cover 3. The rotor bearing 40 is held in the bearing box 24. The front end of the rotor shaft 33 is positioned in the internal space of the hammer case 4 through an opening in the bearing box 24.

[0064] A pinion gear 41 is formed at 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.

[0065] The reduction mechanism 7 transmits the rotational force of the motor 6 to the spindle 8 and anvil 10. The reduction mechanism 7 is housed in the rear cylindrical portion 4A of the hammer case 4. The reduction mechanism 7 has multiple gears. The reduction mechanism 7 is positioned in front 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.

[0066] The reduction gear 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. Each of the pinion gear 41, planetary gears 42, and internal gear 43 is housed in a hammer case 4 and a bearing box 24. Each of the plurality of planetary gears 42 meshes with the pinion gear 41. The planetary gears 42 are rotatably supported on the spindle 8 via pins 42P. The spindle 8 is rotated by the planetary gears 42. The internal gear 43 has internal teeth that mesh with the planetary gears 42. The internal gear 43 is fixed to the bearing box 24. The internal gear 43 is always immobile relative to the bearing box 24.

[0067] When the rotor shaft 33 rotates due to 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 revolving of the planetary gear 42, the spindle 8, which is connected to the planetary gear 42 via pin 42P, rotates at a lower rotational speed than the rotational speed of the rotor shaft 33.

[0068] The spindle 8 rotates due to the rotational force of the motor 6. The spindle 8 is positioned in front of at least a portion of the motor 6. The spindle 8 is positioned in front of the stator 26. At least a portion of the spindle 8 is positioned in front of the rotor 27. At least a portion of the spindle 8 is positioned in front 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.

[0069] 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 axis of rotation of the spindle 8 coincides with the axis of rotation AX of the motor 6. The spindle 8 rotates around the axis of rotation AX.

[0070] The spindle 8 is rotatably supported by a spindle bearing 44. The spindle bearing 44 is held in a bearing box 24. The spindle 8 has an annular portion 8C that protrudes rearward from the rear of the flange portion 8A. The spindle bearing 44 is positioned inside the annular portion 8C. In this embodiment, the outer ring of the spindle bearing 44 is connected to the annular portion 8C, and the inner ring of the spindle bearing 44 is supported in the bearing box 24.

[0071] 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 gear 7 and a spindle 8. The striking mechanism 9 strikes the anvil 10 in a rotational direction based on the rotational force of the spindle 8, which is rotated by the motor 6. The striking mechanism 9 includes 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.

[0072] The hammer 47 is positioned in front of the reduction mechanism 7. The hammer 47 is housed in the rear cylindrical section 4A. The hammer 47 is positioned around the spindle shaft section 8B. The hammer 47 is held by the spindle shaft section 8B. The ball 48 is positioned between the spindle shaft section 8B and the hammer 47. The coil spring 49 is supported by the flange section 8A and the hammer 47, respectively.

[0073] 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 gear 7 and the spindle 8. The hammer 47 is rotatable together with the spindle 8, which is rotated by the motor 6, based on the rotational force of the spindle 8. The axis of rotation of the hammer 47, the axis of rotation of the spindle 8, and the axis of rotation AX of the motor 6 coincide. The hammer 47 rotates around the axis of rotation AX.

[0074] The ball 48 is made of a metal such as steel. The ball 48 is positioned 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 positioned. 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 positioned. The hammer groove 47A is provided on a portion of the inner surface of the hammer 47. The ball 48 is positioned 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, respectively. 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 and rotational directions within the range of motion defined by the spindle groove 8D and the hammer groove 47A.

[0075] The coil spring 49 generates an elastic force that moves the hammer 47 forward. The coil spring 49 is positioned 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 positioned inside the recess 47C and supported by the washer 45.

[0076] The anvil 10 is the output section of the impact tool 1, which is operated by the rotational force of the motor 6. The anvil 10 rotates due to the rotational force of the motor 6. The anvil 10 is positioned in front of the motor 6. At least a portion of the anvil 10 is positioned in front of the hammer 47. The anvil 10 has a tool hole 10A into which a tip tool 90 is inserted. A screwdriver bit is exemplified as the tip tool 90. The tool hole 10A is provided at the front end of the anvil 10. The tip tool 90 is mounted on the anvil 10. A recess 10B is provided at the rear end of the anvil 10. A protrusion is provided at the front end of the spindle shaft portion 8B. The protrusion at the front end of the spindle shaft portion 8B is inserted into the recess 10B provided at the rear end of the anvil 10.

[0077] The anvil 10 has a rod-shaped anvil shaft portion 10C and an anvil projection portion 10D. The tool hole 10A is provided at the front end of the anvil shaft portion 10C. The tip tool 90 is mounted on the anvil shaft portion 10C. The anvil projection portion 10D is provided at the rear end of the anvil 10. The anvil projection portion 10D protrudes radially outward from the rear end of the anvil shaft portion 10C.

[0078] The anvil 10 is rotatably supported by an anvil bearing 46. The axis of rotation of the anvil 10 coincides with the axis of rotation of the hammer 47, the axis of rotation of the spindle 8, and the axis of rotation AX of the motor 6. The anvil 10 rotates around axis AX. The anvil bearing 46 is located inside the front cylindrical portion 4B. The anvil bearing 46 is held in 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 arranged in the front-rear direction.

[0079] The hammer 47 has a hammer projection 47B that protrudes forward. The hammer projection 47B is capable of contacting the anvil projection 10D. When the motor 6 is driven while the hammer projection 47B and the anvil projection 10D are in contact, the anvil 10 rotates together with the hammer 47 and the spindle 8.

[0080] The anvil 10 is struck in the rotational direction by the hammer 47. For example, in screw tightening work, if the load acting on the anvil 10 becomes high, there may be situations where the power generated by the motor 6 alone is insufficient to rotate the anvil 10. When the power generated by the motor 6 alone is insufficient to rotate the anvil 10, the rotation of the anvil 10 and the hammer 47 stops. The spindle 8 and the hammer 47 are relatively movable in the axial and circumferential directions, respectively, via the ball 48. Even if the rotation of the hammer 47 stops, the rotation of the spindle 8 continues due to the power generated by the motor 6. When the spindle 8 rotates while the rotation of the hammer 47 has stopped, the ball 48 moves backward, guided by the spindle groove 8D and the hammer groove 47A, respectively. The hammer 47 receives force from the ball 48 and moves backward along with the ball 48. In other words, the hammer 47 moves backward when the spindle 8 rotates while the rotation of the anvil 10 has stopped. As the hammer 47 moves backward, contact between the hammer projection 47B and the anvil projection 10D is released.

[0081] The coil spring 49 generates an elastic force that moves the hammer 47 forward. The hammer 47, having moved backward, 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, the hammer projection 47B comes into contact with the anvil projection 10D while rotating. As a result, the anvil projection 10D is struck in the rotational direction by the hammer projection 47B. The anvil 10 is subjected to both the power of the motor 6 and the inertial force of the hammer 47. Therefore, the anvil 10 can rotate around the rotation axis AX with high torque.

[0082] The tool holding mechanism 11 is positioned around the front of the anvil 10. The tool holding mechanism 11 holds the tip tool 90 inserted into the tool hole 10A.

[0083] Fan 12 rotates due to the rotational force of motor 6. Fan 12 is positioned behind the stator 26 of motor 6. Fan 12 generates airflow to cool motor 6. Fan 12 is fixed to at least a portion of rotor 27. Fan 12 is fixed to the rear of rotor shaft portion 33 via bush 12A. Fan 12 is positioned between rotor bearing 39 and stator 26. Fan 12 rotates with the rotation of rotor 27. As rotor shaft portion 33 rotates, fan 12 rotates together with rotor shaft portion 33. As fan 12 rotates, air from the external space of housing 2 flows into the internal space of housing 2 through intake port 19. The air that flows into the internal space of housing 2 cools motor 6 by circulating through the internal space of housing 2. The air that has circulated through the internal space of housing 2 flows out to the external space of housing 2 through exhaust port 20 as fan 12 rotates.

[0084] The battery mounting section 13 is located below the battery holding section 23. The battery pack 25 is mounted in the battery mounting section 13. The battery pack 25 is detachable from the battery mounting 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. By being mounted in the battery mounting 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 based on the power supplied from the battery pack 25.

[0085] The trigger lever 14 is located on the grip portion 22. The trigger lever 14 is operated by the operator to start the motor 6. By operating the trigger lever 14, the motor 6 is switched between running and stopping.

[0086] The forward / reverse rotation switch lever 15 is located on the upper part of the grip section 22. The forward / reverse rotation switch lever 15 is operated by the operator. When the forward / reverse rotation switch lever 15 is operated, the rotation direction of the motor 6 is switched from one direction to the other. When the rotation direction of the motor 6 is switched, the rotation direction of the spindle 8 is switched.

[0087] The hand-operated mode switching button 16 is located above the trigger lever 14. The hand-operated mode switching button 16 is operated by the operator. A circuit board 16A and a switch 16B are located behind the hand-operated mode switching button 16. The switch 16B is mounted on the front of the circuit board 16A. The hand-operated mode switching button 16 is located in front of the switch 16B. When the hand-operated mode switching button 16 is pushed backward, the switch 16B is activated and an operation signal is output from the circuit board 16A. The operation signal output from the circuit board 16A is transmitted to a controller (not shown). The controller switches the control mode of the motor 6 based on the operation signal output from the circuit board 16A.

[0088] [Light Unit] Figure 5 is a cross-sectional view showing a part of the light unit 18 according to this embodiment. Figure 6 is an exploded perspective view from the front showing the upper part of the impact tool 1 according to this embodiment. Figure 7 is a front perspective view showing the light unit 18 according to this embodiment. Figure 8 is a rear perspective view showing the light unit 18 according to this embodiment. Figure 9 is an exploded perspective view from the front showing the light unit 18 according to this embodiment. Figure 10 is an exploded perspective view from the rear showing the light unit 18 according to this embodiment.

[0089] The light unit 18 emits illumination light. The light unit 18 illuminates the anvil 10 and its surroundings with illumination light. The light unit 18 illuminates the area in front of the anvil 10 with illumination light. The light unit 18 also illuminates the tip tool 90 attached to the anvil 10 and its surroundings with illumination light. The light unit 18 also illuminates the workpiece of the impact tool 1 with illumination light.

[0090] The light unit 18 is positioned at the front of the hammer case 4. The light unit 18 is positioned around the front cylindrical portion 4B. The light unit 18 is positioned around the anvil shaft portion 10C via the front cylindrical portion 4B.

[0091] The light unit 18 includes a chip-on-board light-emitting diode 50 (COB LED), an optical element 57, and a light-shielding element 60.

[0092] The chip-on-board light-emitting diode 50 comprises a substrate 51, an LED chip 52 which is a light-emitting element, a bank 54, a phosphor 55, and a resistor 59.

[0093] Figure 11 is a front view of the chip-on-board light-emitting diode 50 according to this embodiment. Note that the phosphor 55 is not shown in Figure 11. Figure 12 is a front view of the substrate 51 according to this embodiment.

[0094] The substrate 51 supports the LED chip 52 and the resistor 59. Examples of substrate 51 include an aluminum substrate, a glass cloth-based epoxy resin substrate (FR-4 substrate), or a composite-based epoxy resin substrate (CEM-3 substrate). The substrate 51 is positioned over at least the upper, left, and right sides of the anvil 10 (anvil shaft portion 10C). In this embodiment, the substrate 51 is annular and positioned around the anvil 10 (anvil shaft portion 10C). A notch may be provided at the bottom of the substrate 51.

[0095] The LED chips 52 are mounted on the front surface of the substrate 51. Multiple LED chips 52 are mounted on the front surface of the substrate 51 at intervals in the circumferential direction of the anvil 10 (anvil shaft portion 10C). The LED chips 52 and the wiring provided on the substrate 51 are connected via gold wires.

[0096] Bank 54 is provided on the front surface of the substrate 51. Bank 54 protrudes forward from the front surface of the substrate 51. Bank 54 is arranged around the LED chip 52. Bank 54 is positioned radially inward and radially outward from the LED chip 52. Bank 54 defines the compartmentalized space in which the phosphor 55 is arranged.

[0097] The phosphor 55 is positioned inside the bank 54 so as to cover the LED chip 52. As shown in Figure 12, the positive electrode 61A and the negative electrode 61B are positioned on the front surface of the substrate 51 outside the bank 54. Alternatively, the positive electrode 61A and the negative electrode 61B may be positioned on the rear surface of the substrate 51. Power output from the battery pack 25 is supplied to the electrodes (positive electrode 61A and negative electrode 61B). The power supplied to the electrodes is then supplied to the LED chip 52 via the substrate 51 and gold wires. 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 5V by a controller (not shown) and applied to the LED chip 52.

[0098] The substrate 51 is annular. The substrate 51 is positioned around the anvil shaft portion 10C via the front cylindrical portion 4B. The substrate 51 has an annular portion 51A positioned around the anvil 10 (anvil shaft portion 10C) and a support portion 51B that protrudes downward from the lower part of the annular portion 51A.

[0099] Multiple LED chips 52 are mounted on the front surface of the annular portion 51A of the substrate 51. The LED chips 52 are arranged around at least a portion of the anvil shaft portion 10C via the front cylindrical portion 4B. Multiple LED chips 52 are arranged on the front surface of the annular portion 51A at intervals in the circumferential direction of the annular portion 51A. In this embodiment, 12 LED chips 52 are arranged on the front surface of the annular portion 51A at equal intervals in the circumferential direction of the annular portion 51A.

[0100] The resistor 59 is mounted on the front of the annular portion 51A. The resistor 59 is positioned between a pair of adjacent LED chips 52 on the front of the annular portion 51A. Multiple resistors 59 are arranged on the front of the annular portion 51A at intervals in the circumferential direction of the annular portion 51A. In this embodiment, twelve resistors 59 are arranged on the front of the annular portion 51A at equal intervals in the circumferential direction of the annular portion 51A.

[0101] Bank 54 is provided on the front surface of the annular portion 51A of the substrate 51. Bank 54 protrudes forward from the front surface of the annular portion 51A. Bank 54 is positioned radially inward and radially outward from the LED chips 52 on the front surface of the annular portion 51A. Bank 54 defines a compartmental space in which the phosphors 55 are arranged. Bank 54 is annular. In this embodiment, bank 54 is provided in the form of a double annular structure. That is, in this embodiment, bank 54 includes an annular first bank 54 provided on the front surface of the annular portion 51A, and an annular second bank 54 provided radially outward from the first bank 54 on the front surface of the annular portion 51A. The first bank 54 is positioned radially inward from the LED chips 52. The second bank 54 is positioned radially outward from the LED chips 52. Multiple LED chips 52 are arranged between the first bank 54 and the second bank 54.

[0102] The phosphor 55 is positioned on the front surface of the annular portion 51A of the substrate 51. The phosphor 55 is annular in shape. The phosphor 55 is positioned inside the bank 54 so as to cover each of the multiple LED chips 52. That is, the phosphor 55 is positioned between the first bank 54 and the second bank 54 so as to cover each of the multiple LED chips 52.

[0103] A pair of lead wires 58 are connected to the circuit board 51. One lead wire 58 is a positive lead wire 58A to which a positive voltage is applied. The other lead wire 58 is a negative lead wire 58B to which a negative voltage is applied. The voltage of the battery pack 25 is applied to the lead wires 58 via a controller (not shown). The positive electrode 61A shown in Figure 12 is connected to the positive lead wire 58A. The negative electrode 61B is connected to the negative lead wire 58B. The pair of lead wires 58 are supported on the rear surface of the support portion 51B. Alternatively, the lead wires 58 may be supported on the front surface of the support portion 51B.

[0104] The current output from the battery pack 25 is supplied to the electrodes (positive electrode 61A and negative electrode 61B) via a controller (not shown) and lead wires 58. The voltage of the battery pack 25 is stepped down by the controller (not shown) and then applied to the electrodes (positive electrode 61A and negative electrode 61B). The current supplied to the electrodes (positive electrode 61A and negative electrode 61B) is supplied to the LED chip 52 via the wiring of the circuit board 51 and gold wires. The LED chip 52 lights up based on the current supplied from the battery pack 25.

[0105] The optical element 57 is connected to the chip-on-board light-emitting diode 50. The optical element 57 is fixed to the substrate 51. The optical element 57 is made of polycarbonate resin. In this embodiment, the optical element 57 is made of polycarbonate resin containing a white diffusing material. At least a portion of the optical element 57 is positioned in front of the chip-on-board light-emitting diode 50. The optical element 57 has an outer cylindrical portion 57A, an inner cylindrical portion 57B, a light-transmitting portion 57C, and a protruding portion 57D.

[0106] The outer cylinder portion 57A is positioned radially outward from the inner cylinder portion 57B. The outer cylinder portion 57A is positioned radially outward from the LED chip 52. In the radial direction, at least a portion of the chip-on-board light-emitting diode 50 is positioned between the outer cylinder portion 57A and the inner cylinder portion 57B. The outer cylinder portion 57A is positioned radially outward from the annular portion 51A of the substrate 51. The inner cylinder portion 57B is positioned radially inward from the annular portion 51A of the substrate 51. The inner cylinder portion 57B is positioned radially inward from the LED chip 52.

[0107] The light-transmitting portion 57C is annular. The light-transmitting portion 57C is positioned in front of the LED chip 52. The light-transmitting portion 57C is positioned 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 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 projected in front of the light unit 18.

[0108] The light-transmitting portion 57C has an incident surface 57E into which light from the LED chip 52 enters, and an exit surface 57F into which light that has passed through the light-transmitting portion 57C is emitted. The front surface of the annular portion 51A faces the incident surface 57E of the light-transmitting portion 57C. The incident surface 57E faces the LED chip 52. The incident surface 57E faces substantially backward. The exit surface 57F faces substantially forward.

[0109] The protrusion 57D is provided so as to protrude downward from the lower part of the outer cylinder portion 57A. A housing space is formed inside the protrusion 57D. The support portion 51B of the substrate 51 is positioned in the housing section formed inside the protrusion 57D.

[0110] The light-shielding member 60 is positioned radially outward from the outer cylinder portion 57A of the optical member 57. The light transmittance of the light-shielding member 60 is lower than that of the optical member 57. At least a portion of the light emitted from the LED chip 52 may pass through the outer cylinder portion 57A. The light-shielding member 60 blocks the light from the LED chip 52 emitted from the outer circumferential surface of the outer cylinder portion 57A. The light-shielding member 60 suppresses the irradiation of the area around the optical member 57 by light from the LED chip 52 emitted from the outer circumferential surface of the outer cylinder portion 57A.

[0111] The light-shielding member 60 is made of synthetic resin. In this embodiment, the light-shielding member 60 is made of polycarbonate resin. The light-shielding member 60 is made of polycarbonate resin containing a colored pigment. Examples of suitable pigments include black pigment or gray pigment. In this embodiment, the light-shielding member 60 is made of polycarbonate resin containing a black pigment. The light-shielding member 60 is black. However, the light-shielding member 60 may also be made of polycarbonate resin containing a gray pigment. The light-shielding member 60 may also be gray.

[0112] The light-shielding member 60 has a cylindrical portion 60A and a protruding portion 60B. The cylindrical portion 60A is arranged to surround the outer cylindrical portion 57A. The cylindrical portion 60A covers the outer circumferential surface of the outer cylindrical portion 57A. The protruding portion 60B protrudes downward from the lower part of the cylindrical portion 60A. The protruding portion 60B covers the outer surface of the protruding portion 57D. The protruding portion 60B is arranged to cover the protruding portion 57D from below.

[0113] The light-shielding member 60 is fixed to the optical member 57. In this embodiment, the optical member 57 and the light-shielding member 60 are fixed together by a first adhesive 70. The first adhesive 70 is placed between the outer circumferential surface of the outer cylinder portion 57A and the inner circumferential surface of the cylinder portion 60A.

[0114] In this embodiment, the light-shielding member 60 has grooves 60D and 60E that are recessed radially outward from the inner circumferential surface of the cylindrical portion 60A. Groove 60D is located behind groove 60E. In the front-rear direction, an abutment surface 60C is provided at the boundary between groove 60D and groove 60E. The abutment surface 60C faces rearward. The abutment surface 60C is annular. The optical member 57 has an opposing surface 57T that faces the abutment surface 60C. The optical member 57 has grooves 57V and 57W that are recessed radially inward from the outer circumferential surface of the optical member 57. Groove 57V is located behind groove 57W. The opposing surface 57T is provided at the boundary between groove 57V and groove 57W. The opposing surface 57T faces forward. The contact surface 60C and the opposing surface 57T are in contact. The first adhesive 70 fills the inside of groove 60D and the inside of groove 60E, respectively. The first adhesive 70 fills the inside of groove 57V and the inside of groove 57W, respectively. The first adhesive 70 accumulates in the space between groove 60D and groove 57V and the space between groove 60E and groove 57W, respectively. The optical member 57 and the light-shielding member 60 are fixed together by the first adhesive 70 filling groove 57V and groove 57W, respectively.

[0115] Furthermore, the light-shielding member 60 has a protrusion 60G that is provided to project radially inward from the inner circumferential surface of the cylindrical portion 60A, forward of the grooves 60D, 60E, 57V, and 57W. The radial inner end of the protrusion 60G contacts the outer circumferential surface of the optical member 57. The protrusion 60G is provided so as to surround the optical member 57. The optical member 57 fits inside the protrusion 60G.

[0116] The front end portion 60F of the light-shielding member 60 is positioned around the emission surface 57F of the light-transmitting portion 57C. The front end portion 60F of the light-shielding member 60 is positioned in front of the front end portion of the light-transmitting portion 57C. In the front-to-back direction, the front end portion 60F of the light-shielding member 60 may be positioned at the same location as the front end portion of the light-transmitting portion 57C. This makes it difficult for light to leak radially outward from the optical member 57.

[0117] The light unit 18, including the chip-on-board light-emitting diode 50 and the light-shielding member 60, is positioned around the anvil shaft portion 10C of the anvil 10. The light unit 18 is positioned around the front cylindrical portion 4B of the hammer case 4. The inner cylindrical portion 57B of the optical member 57 is positioned around the front cylindrical portion 4B of the hammer case 4. The inner cylindrical portion 57B of the optical member 57 is supported by the front cylindrical portion 4B of the hammer case 4. The inner cylindrical portion 57B of the optical member 57 is fixed to the front cylindrical portion 4B of the hammer case 4 so as not to move in the axial direction.

[0118] In the radial direction, the substrate 51 is positioned between the outer cylinder portion 57A and the inner cylinder portion 57B. The substrate 51 is fixed to the optical member 57. As shown in Figure 5, the substrate 51 and the optical member 57 are fixed together by a second adhesive 75. The second adhesive 75 fixes the rear surface of the substrate 51 to the inner circumferential surface of the outer cylinder portion 57A. Alternatively, the second adhesive 75 may also fix the rear surface of the substrate 51 to the outer circumferential surface of the inner cylinder portion 57B. The second adhesive 75 is light-shielding. In this embodiment, the second adhesive 75 is a black adhesive.

[0119] As shown in Figures 5 and 6, a protrusion 4D is provided on the outer circumferential surface of the front cylindrical portion 4B. The protrusion 4D projects radially outward from the outer circumferential surface of the front cylindrical portion 4B. Multiple 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 backward and an inclined surface 4F that slopes radially inward toward the front.

[0120] The light unit 18 is supported by the front cylindrical portion 4B of the hammer case 4. A rear sliding portion 57M and a front sliding portion 57N are provided on the inner circumferential surface of the inner cylindrical portion 57B of the optical member 57. Each of the rear sliding portion 57M and the front sliding portion 57N protrudes radially inward from the inner circumferential surface of the inner cylindrical portion 57B. The front sliding portion 57N is positioned in front of the rear sliding portion 57M. Four rear sliding portions 57M are provided, spaced apart in the circumferential direction. The front sliding portion 57N is positioned in front of each of the four rear sliding portions 57M. A recess 57K is provided between the rear sliding portion 57M and the front sliding portion 57N. The convex portion 4D is positioned inside the recess 57K. The rear sliding portion 57M has a front surface 57P that contacts the rear surface 4E of the convex portion 4D. The front sliding portion 57N has an inclined surface 57Q that faces the inclined surface 4F of the protruding portion 4D.

[0121] An insertion opening is provided between one circumferential end of the rear sliding portion 57M and the front sliding portion 57N. The protrusion 4D is positioned in the recess 57K via the insertion opening. After the protrusion 4D is inserted into the insertion opening, the light unit 18 is rotated, causing the protrusion 4D to be inserted into the inside of the recess 57K. This fixes the optical member 57 and the front cylindrical portion 4B of the hammer case 4. The fixing of the optical member 57 and the front cylindrical portion 4B of the hammer case 4 fixes the light unit 18 and the hammer case 4.

[0122] Light emitted from the LED chip 52 enters the incident surface 57E via the phosphor 55. As shown in Figure 5, the incident surface 57E is tilted forward toward the radially inward direction. The light that enters the incident surface 57E passes through the light-transmitting section 57C and is then emitted from the exit surface 57F.

[0123] At least a portion of the light incident on the incident surface 57E reaches the inclined surface 57Q. The inclined surface 57Q is tilted forward radially inward. The light that reaches the inclined surface 57Q undergoes total internal reflection and propagates forward. The light that undergoes total internal reflection at the inclined surface 57Q is emitted from the exit surface 57F.

[0124] In this embodiment, a sponge ring 80 is positioned behind the chip-on-board light-emitting diode 50. The rear surface of the sponge ring 80 is supported by the annular portion 4C of the hammer case 4. At least a portion of the sponge ring 80 contacts the light unit 18 in a compressed state. In the example shown in Figure 5, the sponge ring 80 contacts the inner cylinder portion 57B of the optical member 57 and the second adhesive 75. By supporting the light unit 18 with the compressed sponge ring 80, rattle of the light unit 18 relative to the hammer case 4 is suppressed. The sponge ring 80 may also support the inner cylinder portion 57B.

[0125] As shown in Figure 11, multiple LED chips 52 are mounted on the front surface of the annular portion 51A of the substrate 51. The LED chips 52 are arranged around at least a portion of the anvil shaft portion 10C via the front cylindrical portion 4B. Multiple LED chips 52 are arranged on the front surface of the annular portion 51A at intervals in the circumferential direction of the annular portion 51A. In this embodiment, 12 LED chips 52 are arranged on the front surface of the annular portion 51A at equal intervals in the circumferential direction of the annular portion 51A.

[0126] The resistor 59 is positioned between a pair of adjacent LED chips 52 on the front surface of the annular portion 51A. Multiple resistors 59 are arranged on the front surface of the annular portion 51A at intervals in the circumferential direction of the annular portion 51A. In this embodiment, twelve resistors 59 are arranged on the front surface of the annular portion 51A at equal intervals in the circumferential direction of the annular portion 51A.

[0127] The LED chips 52 and resistors 59 are arranged alternately, one by one, in the circumferential direction on the front surface of the annular portion 51A.

[0128] Bank 54 includes an annular first bank 54 provided on the front surface of the annular portion 51A, and an annular second bank 54 provided on the front surface of the annular portion 51A radially outward from the first bank 54. Each of the multiple LED chips 52 and multiple resistors 59 is arranged between the first bank 54 and the second bank 54.

[0129] A vertex portion 51T is defined on a part of the annular portion 51A directly above the anvil shaft portion 10C of the anvil 10. The position of the vertex portion 51T in the circumferential direction is defined as the 0° position. The 0° position is the position directly above the axis of rotation AX (anvil shaft portion 10C). The 180° position is the position directly below the axis of rotation AX (anvil shaft portion 10C).

[0130] The LED chip 52 closest to the apex 51T of the substrate 51 directly above the anvil shaft portion 10C is positioned at a predetermined angle θ shifted circumferentially from the apex 51T. In this embodiment, the predetermined angle θ is 15°. The LED chips 52 are positioned at 15°, 45°, 75°, 105°, 135°, 165°, 195°, 225°, 255°, 285°, 315°, and 345° around the rotation axis AX.

[0131] One resistor 59 is positioned at the apex 51T. The resistors 59 are positioned at the following locations around the rotation axis AX: 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, and 330°.

[0132] Multiple LED chips 52 are positioned symmetrically with respect to a straight line extending vertically through the central axis (rotation axis AX) and apex 51T of the anvil shaft portion 10C. Multiple resistors 59 are positioned symmetrically with respect to a straight line extending vertically through the central axis (rotation axis AX) and apex 51T of the anvil shaft portion 10C.

[0133] As shown in Figure 12, a positive electrode 61A and a negative electrode 61B are provided on the front surface of the support portion 51B of the substrate 51. The positive electrode 61A and the negative electrode 61B are located outside the bank 54. The positive electrode 61A is connected to a positive lead wire 58A. The negative electrode 61B is connected to a negative lead wire 58B. A positive voltage is applied to the positive electrode 61A by the battery pack 25 via the positive lead wire 58A. A negative voltage is applied to the negative electrode 61B by the battery pack 25 via the negative lead wire 58B. Each of the multiple LED chips 52 is connected in parallel to the positive electrode 61A and the negative electrode 61B. In this embodiment, a positive relay line 62A and a negative relay line 62B are provided on the front surface of the annular portion 51A. Each of the positive relay line 62A and the negative relay line 62B is substantially annular. The positive relay line 62A is located radially inward from the LED chip 52. The negative relay line 62B is positioned radially outward from the LED chip 52. Multiple positive power lines 63A branch off from the positive relay line 62A. Multiple negative power lines 63B branch off from the negative relay line 62B. Twelve positive power lines 63A are provided. Twelve negative power lines 63B are provided. Each of the positive power lines 63A and negative power lines 63B is provided on the front of the annular portion 51A. The positive power lines 63A and negative power lines 63B are connected to each of the multiple LED chips 52. One positive power line 63A and one negative power line 63B are connected to each LED chip 52. A resistor 59 (not shown in Figure 12) is placed on each of the multiple positive power lines 63A. One resistor 59 is placed on each positive power line 63A.

[0134] The current output from the battery pack 25 is supplied to the positive electrode 61A via a controller (not shown) and a positive lead wire 58A. The current supplied to the positive electrode 61A is then supplied to each of the 12 LED chips 52 via a positive relay line 62A and a positive power line 63A. The LED chips 52 light up based on the power supplied from the battery pack 25.

[0135] [Assembly method] When assembling the light unit 18, first, the light-shielding member 60 is attached to the optical member 57. When attaching the light-shielding member 60 to the optical member 57, the optical member 57 is placed on a predetermined support surface so that the ejection surface 57F faces upward. After the optical member 57 is placed on the support surface, the first adhesive 70 is applied to the outer circumferential surface of the optical member 57, including the opposing surface 57T. In this embodiment, the first adhesive 70 is applied to the grooves 57V and 57W. After the first adhesive 70 is applied to the grooves 57V and 57W, the light-shielding member 60 is inserted into the optical member 57 from above. Alternatively, the first adhesive 70 may be applied to the grooves 60D and 60E of the light-shielding member 60 before the light-shielding member 60 is inserted into the optical member 57. When the light-shielding member 60 is inserted into the optical member 57, the abutment surface 60C and the opposing surface 57T come into contact. Furthermore, the front part of the optical member 57 fits into the protrusion 60G. The optical member 57 is lightly press-fitted into the inside of the protrusion 60G. When the light-shielding member 60 is lightly press-fitted into the optical member 57, the first adhesive 70 wets and spreads in the grooves 57V and 57W. Since the first adhesive 70 applied to the grooves 57V and 57W does not easily move upward, it does not reach the injection surface 57F even when the light-shielding member 60 is inserted into the optical member 57. In addition, the radial inner end of the protrusion 60G contacts the outer circumferential surface of the optical member 57, which also prevents the first adhesive 70 applied to the grooves 57V and 57W from reaching the injection surface 57F. Although at least a portion of the first adhesive 70 may flow between the rear end (lower end) of the outer cylinder portion 57A of the optical member 57 and the rear end of the inner circumferential surface of the light-shielding member 60, it does not flow onto the injection surface 57F, thus preventing contamination of the injection surface 57F with the first adhesive 70. Furthermore, since the first adhesive 70 does not adhere to the injection surface 57F, the obstruction of light emitted from the injection surface 57F by the first adhesive 70 is prevented. In addition, the substrate 51 and the optical member 57 are fixed together by the second adhesive 75.

[0136] After the optical member 57, the light-shielding member 60, and the chip-on-board light-emitting diode 50 are fixed by the first adhesive 70 and the second adhesive 75, the light unit 18 and the hammer case 4 are fixed together. As described above, after the protrusion 4D is inserted into the opening provided between one circumferential end of the rear slide portion 57M and the front slide portion 57N, the light unit 18 is rotated, causing the protrusion 4D to be inserted into the recess 57K. This fixes the light unit 18 and the hammer case 4 together. The sponge ring 80 supported by the annular portion 4C contacts at least a part of the light unit 18, thereby suppressing play of the light unit 18 relative to the hammer case 4. The inner cylinder portion 57B of the optical element 57 is fixed to the front cylinder portion 4B of the hammer case 4, thereby fixing the light unit 18 to the hammer case 4 only in the axial direction. Then, the hammer case 4 and the protrusion 60B of the light shielding member 60 are sandwiched between the left housing 2L and the right housing 2R, fixing the hammer case 4 and the light unit 18 to the housing 2 in the rotational direction. Subsequently, the left housing 2L and the right housing 2R are fixed together by screws 2S.

[0137] [How to use] When the operator operates the trigger lever 14, the motor 6 starts up and light is emitted from the LED chip 52 of the chip-on-board light-emitting diode 50. The brightness of the light emitted from the chip-on-board light-emitting diode 50 is high, allowing the workpiece to be brightly illuminated.

[0138] On the other hand, if at least a portion of the light emitted from the LED chip 52 passes through the outer cylinder portion 57A, and the light emitted from the outer surface of the outer cylinder portion 57A enters the worker's eyes, the worker may experience glare, which could make it difficult to see the work object. In this embodiment, the light-shielding member 60 suppresses the worker from experiencing glare.

[0139] [effect] As described above, in this embodiment, the impact tool 1 comprises a motor 6, a housing 2 having a motor housing 21 that houses the motor 6 and a grip portion 22 that protrudes downward from the motor housing 21, an anvil 10 which is an output unit positioned in front of the motor 6 and operated by the rotational force of the motor 6, a substrate 51 positioned above, to the left of, and to the right of the anvil 10, and a plurality of LED chips 52 which are light-emitting elements mounted on the front surface of the substrate 51 at intervals in the circumferential direction of the anvil 10. The LED chip 52 closest to the apex 51T of the substrate 51 directly above the anvil 10 is positioned at a predetermined angle θ shifted circumferentially from the apex 51T.

[0140] In the above configuration, if the light unit 18 has a substrate 51 and an LED chip 52, even if an impact is applied to the top 51T of the substrate 51, for example, by dropping an impact tool 1, the LED chip 52 is not located at the top 51T of the substrate 51. Therefore, damage to the LED chip 52 or separation of the LED chip 52 from the substrate 51 is suppressed. As a result, failure of the LED chip 52 to light up is suppressed. Consequently, a decrease in the light emission performance of the light unit 18 is suppressed.

[0141] Figure 13 is a schematic diagram showing the impact tool 1 according to this embodiment in a dropped state. When the impact tool 1 falls and the upper part of the light unit 18 hits the ground (floor), the light unit 18 is subjected to impact. As described above, the light unit 18 includes banks 54 positioned radially inward and radially outward from the LED chip 52 on the front surface of the annular portion 51A, a phosphor 55 positioned inside the bank 54 to cover the LED chip 52, and an optical member 57 having an outer cylinder portion 57A positioned radially outward from the annular portion 51A and a light-transmitting portion 57C positioned in front of the LED chip 52 through which light emitted from the LED chip 52 passes. When the impact tool 1 falls, impact is applied to the apex portion 51T of the annular portion 51A, and there is a possibility that impact will be applied to the bank 54 via the outer cylinder portion 57A of the optical member 57. If an impact is applied to the bank 54 of the apex portion 51T, the bank 54 of the apex portion 51T may deform or break. If an LED chip 52 is located on the apex portion 51T, an impact applied to the optical member 57 may be transmitted to the LED chip 52 via the bank 54. In this embodiment, since an LED chip 52 is not located on the apex portion 51T, even if an impact is applied to the bank 54 of the apex portion 51T and the bank 54 of the apex portion 51T deforms or breaks, the impact on the LED chip 52 is suppressed. Therefore, damage to the LED chip 52 or separation of the LED chip 52 from the substrate is suppressed. Consequently, failure of the LED chip 52 to light up is suppressed, and a decrease in the light emission performance of the light unit 18 is suppressed.

[0142] In this embodiment, the multiple LED chips 52 are arranged in positions symmetrical with respect to a straight line extending vertically through the central axis (rotation axis AX) and the vertex portion 51T of the anvil 10.

[0143] In the above configuration, the workpiece of the impact tool 1 is properly illuminated by multiple LED chips 52.

[0144] In this embodiment, the substrate 51 has an annular portion 51A that is arranged around the anvil 10. Multiple LED chips 52 are mounted on the front surface of the annular portion 51A.

[0145] In the above configuration, multiple LED chips 52 are mounted on the front surface of the annular portion 51A of the circuit board 51, so that the workpiece of the impact tool 1 is properly illuminated.

[0146] In this embodiment, the multiple LED chips 52 are arranged at equal intervals in the circumferential direction on the front surface of the annular portion 51A.

[0147] In the above configuration, multiple LED chips 52 are mounted at equal intervals on the front surface of the ring portion 51A of the circuit board 51, so that the workpiece of the impact tool 1 is properly illuminated.

[0148] In this embodiment, the light unit 18 has a positive electrode 61A provided on the substrate 51 to which a positive voltage is applied, and a negative electrode 61B provided on the substrate 51 to which a negative voltage is applied. Each of the plurality of LED chips 52 is connected in parallel to the positive electrode 61A and the negative electrode 61B.

[0149] In the above configuration, multiple LED chips 52 are connected in parallel, so even if, for example, one LED chip 52 fails or goes out of illumination, power is supplied to the other LED chips 52, thus preventing the other LED chips 52 from going out of illumination.

[0150] In this embodiment, the light unit 18 is provided on a substrate 51 and includes a positive power line 63A and a negative power line 63B connected to each of the plurality of LED chips 52, and a resistor 59 placed on at least one of the positive power line 63A and the negative power line 63B.

[0151] In the above configuration, the voltage applied to the LED chip 52 is adjusted by the resistor 59. The resistor 59, for example, equalizes the brightness of multiple LED chips 52.

[0152] In this embodiment, the resistor 59 is positioned between a pair of LED chips 52 that are adjacent to each other on the front surface of the substrate 51.

[0153] In the above configuration, the LED chip 52 and the resistor 59 are properly mounted on the front of the circuit board 51.

[0154] In this embodiment, the resistor 59 is positioned at the vertex portion 51T.

[0155] In the above configuration, even if an impact is applied to the top 51T of the circuit board 51, for example, by dropping the impact tool 1, the resistor 59 is less likely to be damaged than the LED chip 52, thus suppressing a decrease in the light-emitting performance of the light unit 18.

[0156] In this embodiment, the LED chip 52 and the resistor 59 are arranged alternately one by one in the circumferential direction on the front surface of the annular portion 51A.

[0157] In the above configuration, the LED chip 52 and the resistor 59 are properly mounted on the front of the ring portion 51A.

[0158] [Other embodiments] Figure 14 is a front view of the substrate 51 of a chip-on-board light-emitting diode 500 according to another embodiment. In the above embodiment, twelve LED chips 52 are arranged at intervals on the annular portion 51A of the substrate 51. As shown in Figure 14, twenty-four LED chips 52 may be arranged at intervals on the annular portion 51A of the substrate 51. Similarly, twenty-four resistors 59 may be arranged at intervals on the annular portion 51A of the substrate 51. The LED chips 52 and resistors 59 are arranged alternately one by one in the circumferential direction on the front surface of the annular portion 51A.

[0159] Figure 15 is a front view of the substrate 511 of a chip-on-board light-emitting diode 501 according to another embodiment. As shown in Figure 15, the substrate 511 has a projection 51C that protrudes upward from the upper part of the annular portion 51A. The upper surface of the projection 51C is a flat surface that extends in the left-right direction.

[0160] In the above configuration, for example, if the impact tool 1 is dropped, the protrusion 51C mitigates the impact applied to the apex of the annular portion 51A. In other words, since the protrusion 51C functions as an impact absorber, excessive impact on the LED chip 52 is suppressed.

[0161] Figure 16 is a front view of the substrate 512 of a chip-on-board light-emitting diode 502 according to another embodiment. As shown in Figure 16, the substrate 512 has a projection 51D that protrudes upward from the top of the annular portion 51A. The upper surface of the projection 51D is a curved surface in which the center of the upper surface in the left-right direction bulges upward.

[0162] Even with the above configuration, if, for example, the impact tool 1 is dropped, the protrusion 51D mitigates the impact applied to the apex of the annular portion 51A. In other words, since the protrusion 51D functions as an impact absorber, excessive impact on the LED chip 52 is suppressed.

[0163] Figure 17 is a front view of the substrate 51 of a chip-on-board light-emitting diode 503 according to another embodiment. In the example shown in Figure 17, one of the twelve LED chips 52, LED chip 52T, is positioned at the apex of the annular portion 51A. The LED chips 52 are positioned at 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, and 330° around the rotation axis AX. In the example shown in Figure 17, the distance between the rotation axis AX (center of the annular portion 51A) and the LED chip 52T is shorter than the distance between the rotation axis AX and the other LED chips 52. That is, the LED chip 52T positioned at the apex is positioned radially inward compared to the other LED chips 52.

[0164] In the above configuration, for example, if the impact tool 1 falls and an impact is applied to the apex of the annular portion 51A, the distance between the outer circumference of the annular portion 51A and the LED chip 52T is long, so excessive impact on the LED chip 52T is suppressed.

[0165] In the above-described embodiment, the light-shielding member 60 is made of polycarbonate resin containing a colored pigment. The light-shielding member 60 may have a black coating applied to the surface of the polycarbonate resin member. The light-shielding member 60 may also be made of rubber, elastomer, or metal.

[0166] In the above embodiment, the impact tool 1 is assumed to be an impact driver. The impact tool 1 may also be an impact wrench.

[0167] In the above-described embodiment, the electric work machine 1 is assumed to be an impact tool, which is a type of power tool. However, power tools are not limited to impact tools. Examples of power tools include driver drills, angle drills, screwdrivers, hammers, hammer drills, circular saws, and reciprocating saws.

[0168] The electric work implement 1 does not have to be an electric tool. Figure 18 is a front perspective view showing an electric work implement 100 according to another embodiment. The electric work implement 100 shown in Figure 18 is an air duster. The electric work implement 100 comprises a housing 200, a battery mounting section 130, a trigger switch 140, an output section 1000, and a light unit 18. The housing 200 has a motor housing section 210, a grip section 220 extending downward from the lower part of the motor housing section 210, and a battery holding section 230 connected to the lower part of the grip section 220. The motor housing section 210 houses a motor and a fan (not shown in Figure 18). The trigger switch 140 is located on the grip section 220. The battery mounting section 130 is located below the battery holding section 230. A battery pack 25 is mounted on the battery mounting section 130. The output section 1000 is operated by the rotational force of the motor. The output unit 1000 is positioned in front of the front end of the motor housing 210. When the motor rotates, the fan rotates, and as a result, air is ejected from the nozzle 1000A of the output unit 1000. The light unit 18 described in the above embodiment may be positioned around the output unit 1000 of the electric work machine 100.

[0169] In the above-described embodiment, the power source for the electric work machine (1, etc.) does not have to be the battery pack 25, but may also be a commercial power source (AC power source). [Explanation of Symbols]

[0170] 1...Electric work tool (impact tool), 2...Housing, 2L...Left housing, 2R...Right housing, 2S...Screw, 3...Rear cover, 3S...Screw, 4...Hammer case, 4A...Rear cylindrical section, 4B...Front cylindrical section, 4C...Annular section, 4D...Convex section, 4E...Rear surface, 4F...Slope, 5...Case cover, 6...Motor, 7...Reduction mechanism, 8...Spindle, 8A...Flange section, 8B...Spindle shaft section, 8C...Annular section, 8D...Spindle groove, 9...Impact mechanism, 10...Anvil (output section), 10A...Tool hole, 10B...Concave section, 10C...Anvil shaft section, 10D...Anvil projection, 11 ...Tool holding mechanism, 12...Fan, 12A...Bush, 13...Battery mounting section, 14...Trigger lever, 15...Forward / reverse rotation switch lever, 16...Handheld mode switch button, 16A...Circuit board, 16B...Switch, 18...Light unit, 19...Air intake, 20...Exhaust port, 21...Motor housing, 22...Grip section, 23...Battery holding section, 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 section, 33...Rotor shaft 34...Rotor magnet, 35...Sensor magnet, 37...Sensor substrate, 37A...Magnetic sensor, 37B...Resin molded body, 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, 47B...Hammer projection, 47C...Recess, 48...Ball, 49...Coil spring, 50...Chip-on-board light-emitting diode, 51...Substrate, 51A...Ring Part, 51B...Support part, 51C...Protruding part, 51D...Protruding part, 51T...Apex part, 52...LED chip (light-emitting element), 54...Bank, 55...Phosphor, 57...Optical component, 57A...Outer cylinder part, 57B...Inner cylinder part, 57C...Light-transmitting part, 57D...Convex part, 57E...Incident surface, 57F...Ejection surface, 57K...Concave part, 57M...Rear slide part, 57N...Front slide part, 57P...Front surface, 57Q...Sloping surface, 57T...Opposite surface, 57V...Groove part, 57W...Groove part, 58...Lead wire, 58A...Positive lead wire, 58B...Negative lead wire, 59...Resistor, 60...Light-shielding member, 60A...Cylinder part, 60B...Convex part,60C... Contact surface, 60D... Groove, 60E... Groove, 60F... Front end, 60G... Protrusion, 61A... Positive electrode, 61B... Negative electrode, 62A... Positive relay line, 62B... Negative relay line, 63A... Positive power line, 63B... Negative power line, 70... First adhesive, 75... Second adhesive, 80... Sponge ring, 90... Tip tool, 100... Electric work tool, 130... Battery mounting section, 140... Trigger switch, 200... Housing, 210... Motor housing, 220... Grip section, 230... Battery holding section, 500... Chip-on-board light-emitting diode, 501... Chip-on-board light-emitting diode, 502... Chip-on-board light-emitting diode, 503... Chip-on-board light-emitting diode, 511... Circuit board, 512... Circuit board, 1000... Output section, 1000A... Nozzle, AX... Rotating shaft.

Claims

1. Motor and, A housing having a motor housing portion for housing the motor and a grip portion protruding downward from the motor housing portion, An output unit positioned in front of the motor and operated by the rotational force of the motor, A circuit board is positioned above, to the left of, and to the right of the output section, Multiple light-emitting elements are mounted on the front surface of the substrate at intervals in the circumferential direction of the output section, The substrate is provided with a power line connected to each of the plurality of light-emitting elements, The power line includes a resistor, The light-emitting element closest to the apex of the substrate directly above the output section is positioned at a location shifted by a predetermined angle in the circumferential direction from the apex. The resistor is positioned between a pair of adjacent light-emitting elements on the front surface of the substrate. Electric work equipment.

2. The multiple light-emitting elements are arranged symmetrically with respect to a straight line extending vertically through the central axis and vertex of the output section. The electric work machine according to claim 1.

3. The substrate has an annular portion arranged around the output section, Multiple light-emitting elements are mounted on the front surface of the annular portion. The electric work machine according to claim 1.

4. Multiple light-emitting elements are arranged at equal intervals in the circumferential direction on the front surface of the annular portion. The electric work machine according to claim 3.

5. Banks are arranged radially inward and radially outward from the light-emitting element on the front surface of the annular portion, A phosphor is disposed inside the bank so as to cover the light-emitting element, The optical member comprises an outer cylindrical portion positioned radially outward from the annular portion and a light-transmitting portion positioned in front of the light-emitting element and through which light emitted from the light-emitting element passes, The electric work machine according to claim 3.

6. The substrate has a projection that protrudes upward from the upper part of the annular portion. The electric work machine according to claim 3.

7. The upper surface of the aforementioned protrusion is a flat surface extending in the left-right direction. The electric work machine according to claim 6.

8. The upper surface of the aforementioned protrusion is a curved surface in which the center of the upper surface in the left-right direction bulges upward. The electric work machine according to claim 6.

9. A positive electrode provided on the substrate to which a positive voltage is applied, The substrate is provided with a negative electrode to which a negative voltage is applied, Each of the multiple light-emitting elements is connected in parallel to the positive electrode and the negative electrode, The electric work machine according to claim 1.

10. The resistor is positioned at the vertex. The electric work machine according to claim 1.

11. The substrate has an annular portion arranged around the output section, The light-emitting element and the resistor are arranged alternately one by one in the circumferential direction on the front surface of the annular portion. The electric work machine according to claim 1.

12. The output section includes an anvil that is struck in the rotational direction by a hammer, The electric work machine according to claim 1.

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