Electric work machine and electric driver drill

Abstract

To provide an electric work machine that is able to set a proper speed mode according to work contents.SOLUTION: An electric work machine includes: a first planetary gear mechanism having a first stage portion including a plurality of first planetary gears disposed around a sun gear and first internal gears disposed around the first planetary gears, and a second stage portion including a plurality of second planetary gears disposed around the sun gear and second internal gears disposed around the second planetary gears; a second planetary gear mechanism that is operated by a rotational force of the first planetary gear mechanism; a spindle; a first speed switching mechanism that switches between a first reduction mode in which rotations of the second internal gears are blocked and rotations of the first internal gears are allowed and a second reduction mode in which rotations of the first internal gears are blocked and rotations of the second internal gears are allowed; and a second speed switching mechanism that switches between a valid mode in which rotations of the internal gears of the second planetary gear mechanism are blocked and an invalid mode in which rotations of the internal gears are allowed.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to an electric power tool and an electric driver drill. [Background technology]

[0002] BACKGROUND ART In the technical field related to electric power tools, a driver drill is known in which the speed mode of a planetary gear can be switched between a high-speed mode and a low-speed mode, as disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-171857 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, when the planetary gear is set to the high-speed mode, the driver drill can perform work at high speed, but may have difficulty performing work requiring high torque.When the planetary gear is set to the low-speed mode, the driver drill can perform work requiring high torque, but may have difficulty performing work at high speed.

[0005] The technology disclosed in this specification aims to provide an electric work machine that can set an appropriate speed mode depending on the type of work being performed. [Means for solving the problem]

[0006] This specification discloses an electric working machine. The electric working machine may include a motor, a first planetary gear mechanism, and a second planetary gear mechanism. The first planetary gear mechanism may have a first stage portion including a plurality of first planetary gears arranged around a sun gear rotated by the motor and a first internal gear arranged around the plurality of first planetary gears, and a second stage portion including a plurality of second planetary gears arranged around the sun gear and a second internal gear arranged around the plurality of second planetary gears. The reduction ratio of the first stage portion may be different from that of the second stage portion. The second planetary gear mechanism may be arranged forward of the first planetary gear mechanism and actuated by the rotational force of the first planetary gear mechanism. The electric working machine may also include a spindle that rotates by the rotational force of the motor transmitted via the second planetary gear mechanism. The electric working machine may also include a first speed change mechanism that switches between a first deceleration mode in which rotation of the second internal gear is prevented and rotation of the first internal gear is allowed, and a second deceleration mode in which rotation of the first internal gear is prevented and rotation of the second internal gear is allowed.The electric working machine may also include a second speed change mechanism that switches between an enabled mode in which rotation of the internal gear of the second planetary gear mechanism is prevented and an disabled mode in which rotation of the internal gear is allowed. [Effects of the Invention]

[0007] The technology disclosed in this specification provides an electric work machine that can set an appropriate speed mode depending on the type of work being performed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front perspective view showing a driver drill according to a first embodiment. [Figure 2] FIG. 2 is a rear perspective view showing the driver drill according to the first embodiment. [Figure 3] FIG. 3 is a side view showing the driver drill according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the driver drill according to the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a part of the driver drill according to the first embodiment. [Figure 6] FIG. 6 is a front perspective view showing a part of the driver drill according to the first embodiment. [Figure 7] FIG. 7 is a front view showing a part of the driver drill according to the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing the reduction mechanism according to the first embodiment. [Figure 12] FIG. 12 is a perspective view showing the reduction mechanism according to the first embodiment, seen from the front right. [Figure 13] FIG. 13 is a perspective view showing the reduction mechanism according to the first embodiment, seen from the front left. [Figure 14] FIG. 14 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 15] FIG. 15 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 16] FIG. 16 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 17] FIG. 17 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 18] FIG. 18 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 19] FIG. 19 is a cross-sectional view showing the power transmission mechanism according to the first embodiment. [Figure 20] FIG. 20 is a front perspective view showing a part of the driver drill according to the second embodiment. [Figure 21] FIG. 21 is a cross-sectional view showing a power transmission mechanism according to the second embodiment. [Figure 22]FIG. 22 is a side view showing the power transmission mechanism according to the second embodiment. [Figure 23] FIG. 23 is a cross-sectional view showing a power transmission mechanism according to the second embodiment. [Figure 24] FIG. 24 is a side view showing the power transmission mechanism according to the second embodiment. [Figure 25] FIG. 25 is a cross-sectional view showing a power transmission mechanism according to the second embodiment. [Figure 26] FIG. 26 is a side view showing the power transmission mechanism according to the second embodiment. [Figure 27] FIG. 27 is a perspective view of a part of the driver drill according to the third embodiment, seen from the front. [Figure 28] FIG. 28 is a side view showing a part of the driver drill according to the third embodiment. [Figure 29] FIG. 29 is a cross-sectional view showing a part of a driver drill according to a third embodiment. [Figure 30] FIG. 30 is an exploded perspective view showing the speed reduction mechanism according to the third embodiment. [Figure 31] FIG. 31 is a perspective view showing a part of the reduction mechanism according to the third embodiment, as seen from behind. [Figure 32] FIG. 32 is a perspective cutaway view from the rear showing a part of the reduction mechanism according to the third embodiment. [Figure 33] FIG. 33 is a side view showing the first speed change mechanism and the second speed change mechanism according to the third embodiment. [Figure 34] FIG. 34 is a perspective view showing the first speed change mechanism and the second speed change mechanism according to the third embodiment, viewed from the lower right rear. [Figure 35] FIG. 35 is a view of the driver drill as viewed from above when the speed reduction mechanism according to the third embodiment is set to the low speed mode (first speed). [Figure 36] FIG. 36 is a cross-sectional view showing the driver drill when the speed reduction mechanism according to the third embodiment is set to the low-speed mode (first speed). [Figure 37]FIG. 37 is a cross-sectional view showing the driver drill when the speed reduction mechanism according to the third embodiment is set to the low-speed mode (first speed). [Figure 38] FIG. 38 is a diagram showing the internal structure of the driver drill when the speed reduction mechanism according to the third embodiment is set to the low speed mode (first speed). [Figure 39] FIG. 39 is a view of the driver drill as viewed from above when the speed reduction mechanism according to the third embodiment is set to the medium speed mode (second speed). [Figure 40] FIG. 40 is a cross-sectional view showing the driver drill when the speed reduction mechanism according to the third embodiment is set to the medium speed mode (second speed). [Figure 41] FIG. 41 is a cross-sectional view showing the driver drill when the speed reduction mechanism according to the third embodiment is set to the medium speed mode (second speed). [Figure 42] FIG. 42 is a diagram showing the internal structure of the driver drill when the speed reduction mechanism according to the third embodiment is set to the medium speed mode (second speed). [Figure 43] FIG. 43 is a view of the driver drill as viewed from above when the speed reduction mechanism according to the third embodiment is set to the high-speed mode (third speed). [Figure 44] FIG. 44 is a cross-sectional view showing the driver drill when the speed reduction mechanism according to the third embodiment is set to the high-speed mode (third speed). [Figure 45] FIG. 45 is a cross-sectional view showing the driver drill when the speed reduction mechanism according to the third embodiment is set to the high-speed mode (third speed). [Figure 46] FIG. 46 is a diagram showing the internal structure of the driver drill when the speed reduction mechanism according to the third embodiment is set to the high-speed mode (third speed). DETAILED DESCRIPTION OF THE INVENTION

[0009] In one or more embodiments, the electric working machine may include a motor, a first planetary gear mechanism, and a second planetary gear mechanism. The first planetary gear mechanism may have a first stage including a plurality of first planetary gears arranged around a sun gear rotated by the motor and a first internal gear arranged around the plurality of first planetary gears, and a second stage including a plurality of second planetary gears arranged around the sun gear and a second internal gear arranged around the plurality of second planetary gears. The reduction ratio of the first stage and the reduction ratio of the second stage may be different. The second planetary gear mechanism may be arranged forward of the first planetary gear mechanism and actuated by the rotational force of the first planetary gear mechanism. The electric working machine may also include a spindle that rotates by the rotational force of the motor transmitted via the second planetary gear mechanism. The electric working machine may also include a first speed change mechanism that switches between a first deceleration mode in which rotation of the second internal gear is prevented and rotation of the first internal gear is allowed, and a second deceleration mode in which rotation of the first internal gear is prevented and rotation of the second internal gear is allowed.The electric working machine may also include a second speed change mechanism that switches between an enabled mode in which rotation of the internal gear of the second planetary gear mechanism is prevented and an disabled mode in which rotation of the internal gear is allowed.

[0010] In the above configuration, the first planetary gear mechanism has a first stage and a second stage. The reduction ratio of the first stage is different from that of the second stage. The first planetary gear mechanism is switched to one of the first reduction mode and the second reduction mode, and the second planetary gear mechanism is switched to one of the enabled mode and the disabled mode, thereby switching the speed mode of the electric working machine among a low-speed mode, a medium-speed mode, and a high-speed mode. This allows the operator to set the electric working machine to an appropriate speed mode depending on the work content.

[0011] In one or more embodiments, the sun gear may include a large diameter portion and a small diameter portion disposed forward of the large diameter portion. The plurality of first planetary gears may be disposed around the large diameter portion. The plurality of second planetary gears may be disposed around the small diameter portion.

[0012] In the above configuration, since the sun gear has a large diameter portion and a small diameter portion, a difference can be generated between the reduction ratio of the first stage portion and the reduction ratio of the second stage portion.

[0013] In one or more embodiments, cam teeth may be provided on an outer peripheral surface of the first internal gear, and cam teeth may be provided on an outer peripheral surface of the second internal gear. The first speed change mechanism may have a contact member that contacts either the cam teeth of the first internal gear or the cam teeth of the second internal gear.

[0014] In the above configuration, the contact member comes into contact with the cam teeth of the first internal gear, thereby preventing rotation of the first internal gear. The contact member comes into contact with the cam teeth of the second internal gear, thereby preventing rotation of the second internal gear.

[0015] In one or more embodiments, each of the first internal gear and the second internal gear may be housed in a casing. The casing may have a guide groove that guides the contact member. The contact member may move, while being guided by the guide groove, between a position facing the outer circumferential surface of the first internal gear and a position facing the outer circumferential surface of the second internal gear.

[0016] In the above configuration, the contact member can move smoothly in the front-rear direction while being guided by the guide groove. Furthermore, by being disposed in the guide groove, the contact member is prevented from moving in the circumferential direction.

[0017] In one or more embodiments, the first speed change mechanism may include an annular member connected to the contact member and disposed around at least one of the first internal gear and the second internal gear. The contact member may be moved by movement of the annular member in the forward and backward directions.

[0018] In the above configuration, when a plurality of contact members are provided at intervals in the circumferential direction, the annular member is connected to each of the plurality of contact members, and when the annular member is moved, each of the plurality of contact members is moved simultaneously.

[0019] In one or more embodiments, the electric operating machine may include a speed selector lever connected to the annular member. The annular member may be moved by operating the speed selector lever to move forward or backward.

[0020] In the above configuration, the speed mode is switched by operating the speed change lever in the forward and backward directions.

[0021] In one or more embodiments, the second speed change mechanism may include a speed change member connected to the speed change lever and the internal gear of the second planetary gear mechanism, respectively, and a cam ring into which the internal gear is inserted to prevent rotation of the internal gear. Operating the speed change lever to move forward or backward may switch between a state in which the internal gear is inserted into the cam ring and a state in which it is removed from the cam ring.

[0022] In the above configuration, the speed mode is switched by operating the speed change lever in the forward and backward directions.

[0023] In one or more embodiments, the motor may include a stator and a rotor including a rotor shaft that rotates relative to the stator. A sun gear may be provided at a forward end of the rotor shaft.

[0024] In the above configuration, the rotational force of the rotor shaft is transmitted directly to the first planetary gear mechanism.

[0025] In one or more embodiments, the electric working machine may include a third planetary gear mechanism disposed forward of the second planetary gear mechanism and actuated by a rotational force of the second planetary gear mechanism. The spindle may be coupled to the third planetary gear mechanism.

[0026] In the above configuration, the rotation speed of the spindle is reduced by the third planetary gear mechanism.

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited thereto. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0028] 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 electric operating machine.

[0029] The electric work machine has a motor. In the embodiments, a direction parallel to a rotation axis AX of the motor will be referred to as an axial direction, a direction circumferentially around the rotation axis AX will be referred to as a circumferential direction or a rotation direction, and a direction radial from the rotation axis AX will be referred to as a radial direction.

[0030] In this embodiment, the rotation axis AX extends in the front-to-rear direction. The axial direction and the front-to-rear direction coincide with each other. One axial side is the front, and the other axial side is the rear. In addition, in the radial direction, a position closer to or approaching the rotation axis AX will be referred to as the radially inner side, and a position farther from or away from the rotation axis AX will be referred to as the radially outer side.

[0031] [First embodiment] A first embodiment will be described below. In the embodiment, the electric operating machine is a driver drill, which is a type of drilling machine.

[0032] <Driver Drill Overview> Fig. 1 is a front perspective view of the driver drill 1 according to the embodiment. Fig. 2 is a rear perspective view of the driver drill 1 according to the embodiment. Fig. 3 is a side view of the driver drill 1 according to the embodiment. Fig. 4 is a cross-sectional view of the driver drill 1 according to the embodiment. In the embodiment, the driver drill 1 is a vibration driver drill.

[0033] As shown in Figures 1, 2, 3, and 4, the driver drill 1 includes a housing 2, a rear cover 3, a casing 4, a battery mounting section 5, a motor 6, a power transmission mechanism 7, an output section 8, a fan 9, a trigger lever 10, a forward / reverse rotation switch lever 11, a speed switch lever 12, a mode switch ring 13, a light 14, an interface panel 15, a dial 16, and a controller 17.

[0034] 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. The left housing 2L and the right housing 2R are fixed together with a screw 2S. The housing 2 is formed by fixing the left housing 2L and the right housing 2R together.

[0035] The housing 2 has a motor accommodating portion 21, a grip portion 22, and a battery holding portion 23.

[0036] The motor accommodating portion 21 accommodates the motor 6. The motor accommodating portion 21 is cylindrical.

[0037] The grip portion 22 is held by an operator. The grip portion 22 is disposed below the motor housing portion 21. The grip portion 22 extends downward from the motor housing portion 21. The trigger lever 10 is disposed in front of the grip portion 22.

[0038] The battery holding portion 23 accommodates the controller 17. The battery holding portion 23 is disposed below the grip portion 22. The battery holding portion 23 is connected to the lower end of the grip portion 22. The external dimensions of the battery holding portion 23 are larger than the external dimensions of the grip portion 22 in both the front-rear and left-right directions.

[0039] 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 houses the fan 9. The rear cover 3 is disposed so as to cover the opening at the rear of the motor housing portion 21. The rear cover 3 is fixed to the motor housing portion 21 with screws 3S.

[0040] The motor accommodating section 21 has an intake port 18. The rear cover 3 has an exhaust port 19. Air from the external space of the housing 2 flows into the internal space of the housing 2 through the intake port 18. Air from the internal space of the housing 2 flows out to the external space of the housing 2 through the exhaust port 19.

[0041] The casing 4 houses the power transmission mechanism 7. The casing 4 includes a first casing 4A, a second casing 4B, a bracket plate 4C, and a stop plate 4D. The second casing 4B is disposed in front of the first casing 4A. The mode switching ring 13 is disposed in front of the second casing 4B. The first casing 4A is made of synthetic resin. The second casing 4B is made of metal. In this embodiment, the second casing 4B is made of aluminum. The casing 4 is disposed in front of the motor accommodating section 21. Each of the first casing 4A and the second casing 4B is cylindrical.

[0042] The first casing 4A is fixed to the rear end of the second casing 4B. The bracket plate 4C is arranged to cover the opening at the rear end of the first casing 4A. The bracket plate 4C is fixed to the rear end of the first casing 4A with screws 4E. The stop plate 4D is arranged to cover the opening at the front end of the second casing 4B. The stop plate 4D is fixed to the front end of the second casing 4B with screws 4F.

[0043] The casing 4 is disposed so as to cover the opening at the front of the motor accommodating portion 21. The first casing 4A is disposed inside the motor accommodating portion 21. The second casing 4B is fixed to the motor accommodating portion 21 with screws 4S.

[0044] The battery attachment section 5 is formed at the bottom of the battery holding section 23. The battery attachment section 5 is connected to the battery pack 20. The battery pack 20 is attached to the battery attachment section 5. The battery pack 20 is detachable from the battery attachment section 5. The battery pack 20 includes a secondary battery. In the embodiment, the battery pack 20 includes a rechargeable lithium-ion battery. When attached to the battery attachment section 5, the battery pack 20 can supply power to the driver drill 1. The motor 6 is driven based on the power supplied from the battery pack 20. The interface panel 15 and the controller 17 operate based on the power supplied from the battery pack 20.

[0045] The motor 6 is a power source for the driver drill 1. The motor 6 is an inner rotor type brushless motor. The motor 6 is housed in the motor housing 21. The motor 6 has a cylindrical stator 61 and a rotor 62 disposed inside the stator 61. The rotor 62 rotates relative to the stator 61. The rotor 62 includes a rotor shaft 63 extending in the axial direction.

[0046] The power transmission mechanism 7 is disposed in front of the motor 6. The power transmission mechanism 7 is housed in the casing 4. The power transmission mechanism 7 connects the rotor shaft 63 and the output unit 8. The power transmission mechanism 7 transmits the power generated by the motor 6 to the output unit 8. The power transmission mechanism 7 has a plurality of gears.

[0047] The power transmission mechanism 7 includes a speed reduction mechanism 30 and a vibration mechanism 40 .

[0048] The reduction mechanism 30 reduces the rotation speed of the rotor shaft 63 and rotates the output section 8 at a lower rotational speed than the rotor shaft 63. In this embodiment, the reduction mechanism 30 has a first planetary gear mechanism 31, a second planetary gear mechanism 32, and a third planetary gear mechanism 33. At least a portion of the first planetary gear mechanism 31 is disposed forward of the motor 6. The second planetary gear mechanism 32 is disposed forward of the first planetary gear mechanism 31. The third planetary gear mechanism 33 is disposed forward of the second planetary gear mechanism 32. The first planetary gear mechanism 31 is operated by the rotational force of the motor 6. The second planetary gear mechanism 32 is operated by the rotational force of the first planetary gear mechanism 31. The third planetary gear mechanism 33 is operated by the rotational force of the second planetary gear mechanism 32.

[0049] The vibration mechanism 40 vibrates the output portion 8 in the axial direction. The vibration mechanism 40 has a first cam 41, a second cam 42, and a vibration switching ring 43.

[0050] The output unit 8 is disposed forward of the motor 6. The output unit 8 rotates due to the rotational force of the motor 6. The output unit 8 rotates with the tool bit attached based on the rotational force transmitted from the motor 6 via the power transmission mechanism 7. The output unit 8 includes a spindle 81 that rotates about the rotation axis AX based on the rotational force transmitted from the motor 6, and a chuck 82 to which the tool bit is attached. At least a portion of the spindle 81 is disposed forward of the third planetary gear mechanism 33. The spindle 81 is connected to the third planetary gear mechanism 33. The spindle 81 rotates due to the rotational force of the motor 6 transmitted via the first planetary gear mechanism 31, the second planetary gear mechanism 32, and the third planetary gear mechanism 33.

[0051] The fan 9 is disposed behind the motor 6. The fan 9 generates an airflow for cooling the motor 6. The fan 9 is fixed to at least a portion of the rotor 62. The fan 9 is fixed to the rear of the rotor shaft 63. The fan 9 rotates with the rotation of the rotor shaft 63. As the rotor shaft 63 rotates, the fan 9 rotates together with the rotor shaft 63. As the fan 9 rotates, air from the external space of the housing 2 flows into the internal space of the housing 2 through the air intake 18. The air that has flowed into the internal space of the housing 2 cools the motor 6 by circulating through the internal space of the housing 2. 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 19.

[0052] The trigger lever 10 is operated to start the motor 6. The trigger lever 10 is provided on the upper part of the grip portion 22. The front end of the trigger lever 10 protrudes forward from the front of the grip portion 22. The trigger lever 10 is movable in the forward and backward directions. The trigger lever 10 is operated by the operator. When the trigger lever 10 is operated so as to move backward, the motor 6 starts. When the operation of the trigger lever 10 is released, the motor 6 stops.

[0053] The forward / reverse switching lever 11 is operated to switch the rotation direction of the motor 6. The forward / reverse switching lever 11 is provided on the upper part of the grip portion 22. The left end of the forward / reverse switching lever 11 protrudes leftward from the left part of the grip portion 22. The right end of the forward / reverse switching lever 11 protrudes rightward from the right part of the grip portion 22. The forward / reverse switching lever 11 can move left and right. The forward / reverse switching lever 11 is operated by the operator. When the forward / reverse switching lever 11 is operated to move leftward, the motor 6 rotates in the forward direction. When the forward / reverse switching lever 11 is operated to move rightward, the motor 6 rotates in the reverse direction. When the rotation direction of the motor 6 is switched, the rotation direction of the spindle 81 is switched.

[0054] The speed switch lever 12 is operated to change the speed mode of the reduction mechanism 30. The speed switch lever 12 is provided on top of the motor housing portion 21. The speed switch lever 12 is movable in the front-rear direction. The speed switch lever 12 is operated by an operator. The speed modes of the reduction mechanism 30 include a low-speed mode, a medium-speed mode, and a high-speed mode. The low-speed mode is a speed mode in which the output unit 8 rotates at a low speed. The medium-speed mode is a speed mode in which the output unit 8 rotates at a medium speed. The high-speed mode is a speed mode in which the output unit 8 rotates at a high speed. The movable range of the speed switch lever 12 is defined in the front-rear direction. When the speed switch lever 12 is operated to move to the front part of the movable range, the speed mode of the reduction mechanism 30 is set to the low-speed mode. When the speed switch lever 12 is operated to move to the middle part of the movable range, the speed mode of the reduction mechanism 30 is set to the medium-speed mode. When the speed change lever 12 is operated to move to the rear of its movable range, the speed mode of the speed reduction mechanism 30 is set to the high speed mode.

[0055] The mode switching ring 13 is operated to change the working mode of the vibration mechanism 40. The mode switching ring 13 is disposed in front of the casing 4. The mode switching ring 13 is rotatable. The mode switching ring 13 is operated by an operator. The working modes of the vibration mechanism 40 include a vibration mode and a non-vibration mode. The vibration mode is a working mode in which the output unit 8 is vibrated in the axial direction. The non-vibration mode is a working mode in which the output unit 8 is not vibrated in the axial direction. By operating the mode switching ring 13 to be positioned at the vibration mode position in the rotational direction, the working mode of the vibration mechanism 40 is set to the vibration mode. By operating the mode switching ring 13 to be positioned at the non-vibration mode position in the rotational direction, the working mode of the vibration mechanism 40 is set to the non-vibration mode.

[0056] The light 14 emits illumination light that illuminates the area in front of the driver drill 1. The light 14 includes, for example, a light-emitting diode (LED). The light 14 is disposed below the front part of the motor housing portion 21. The light 14 is disposed above the trigger lever 10.

[0057] The interface panel 15 is provided in the battery holding section 23. The interface panel 15 includes an operating device 24 and a display device 25. The interface panel 15 is plate-shaped. The operating device 24 includes operation buttons. Examples of the display device 25 include a segment display including a plurality of segment light emitters, a flat panel display such as a liquid crystal display, and an indicator-type display in which a plurality of light-emitting diodes are arranged.

[0058] A panel opening 27 is formed in the battery holding portion 23. The panel opening 27 is formed in the upper surface of the battery holding portion 23, forward of the grip portion 22. At least a portion of the interface panel 15 is disposed in the panel opening 27.

[0059] The operating device 24 is operated to change the drive mode of the motor 6. The operating device 24 is operated by an operator. The drive modes of the motor 6 include a drill mode and a clutch mode. The drill mode is a drive mode in which the motor 6 is driven regardless of the torque acting on the motor 6 when the motor 6 is driven. The clutch mode is a drive mode in which the motor 6 is stopped when the torque acting on the motor 6 exceeds a torque threshold when the motor 6 is driven.

[0060] The dial 16 is operated to change the driving conditions of the motor 6. The dial 16 is disposed in front of the battery holding portion 23. The dial 16 is rotatably supported by the battery holding portion 23. The dial 16 is rotatable 360° or more. The dial 16 is operated by an operator. The driving conditions of the motor 6 include a torque threshold. The dial 16 is operated to change the torque threshold in the clutch mode set by the operating device 24.

[0061] A dial opening is formed in the battery holding portion 23. The dial opening is formed on the right side of the front portion of the battery holding portion 23. At least a portion of the dial 16 is disposed in the dial opening .

[0062] The controller 17 includes a computer system. The controller 17 outputs a control command to control the motor 6. At least a portion of the controller 17 is housed in a controller case 26. The controller 17 is housed in the battery holding section 23 while being held in the controller case 26. The controller 17 includes a circuit board on which a plurality of electronic components are mounted. Examples of the 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), a transistor, a capacitor, and a resistor.

[0063] The controller 17 sets the driving conditions of the motor 6 based on the operation of the dial 16. As described above, the driving conditions of the motor 6 include a torque threshold. In the clutch mode, the controller 17 sets the torque threshold based on the operation of the dial 16.

[0064] Furthermore, in the clutch mode, the controller 17 stops the motor 6 when the torque acting on the motor 6 during driving of the motor 6 exceeds a set torque threshold.

[0065] Furthermore, the controller 17 causes the display device 25 to display the set driving conditions of the motor 6. The controller 17 causes the display device 25 to display the set torque threshold.

[0066] <Motor and power transmission mechanism> Fig. 5 is a cross-sectional view showing a portion of the driver drill 1 according to the embodiment. As shown in Fig. 5, the motor 6 has a cylindrical stator 61 and a rotor 62 disposed inside the stator 61. The rotor 62 includes a rotor shaft 63 extending in the axial direction.

[0067] The stator 61 includes a stator core 61A including a plurality of stacked steel plates, a front insulator 61B disposed in front of the stator core 61A, a rear insulator 61C disposed in the rear of the stator core 61A, a plurality of coils 61D wound around the stator core 61A via the front insulator 61B and the rear insulator 61C, a sensor circuit board 61E attached to the front insulator 61B, and a short-circuit member 61F supported by the front insulator 61B. The sensor circuit board 61E has a plurality of rotation detection elements that detect the rotation of the rotor 62. The short-circuit member 61F connects the plurality of coils 61D via fusing terminals. The short-circuit member 61F is connected to the controller 17 via lead wires.

[0068] The rotor 62 rotates about a rotation axis AX. The rotor 62 has a rotor shaft 63, a rotor core 62A arranged around the rotor shaft 63, and a plurality of permanent magnets 62B held by the rotor core 62A. The rotor core 62A is cylindrical. The rotor core 62A includes a plurality of laminated steel plates. The rotor core 62A has through holes extending in the axial direction. A plurality of through holes are formed in the circumferential direction. The permanent magnets 62B are arranged in each of the plurality of through holes of the rotor core 62A.

[0069] The rotation detection element of the sensor circuit board 61E detects the magnetic field of the permanent magnet 62B, thereby detecting the rotation of the rotor 62. The controller 17 supplies a drive current to the coil 61D based on the detection data of the rotation detection element.

[0070] The rotor shaft 63 rotates around a rotation axis AX. The rotation axis AX of the rotor shaft 63 coincides with the rotation axis of the output section 8. A front portion of the rotor shaft 63 is rotatably supported by a bearing 64. A rear portion of the rotor shaft 63 is rotatably supported by a bearing 65. The bearing 64 is held by a bracket plate 4C arranged in front of the stator 61. The bearing 65 is held by the rear cover 3. The front end portion of the rotor shaft 63 is arranged forward of the bearing 64. The front end portion of the rotor shaft 63 is arranged in the internal space of the casing 4.

[0071] A pinion gear 31S is provided at the front end of the rotor shaft 63. The pinion gear 31S functions as a sun gear of the first planetary gear mechanism 31. The pinion gear 31S is rotated by the motor 6. The pinion gear 31S includes a large diameter portion 311S and a small diameter portion 312S disposed forward of the large diameter portion 311S. The rotor shaft 63 is connected to the first planetary gear mechanism 31 of the reduction mechanism 30 via the pinion gear 31S.

[0072] The first planetary gear mechanism 31 has a planetary gear 311P, a planetary gear 312P arranged forward of the planetary gear 311P, a first carrier 31C supporting each of the multiple planetary gears 311P and the multiple planetary gears 312P, an internal gear 311R arranged around the multiple planetary gears 311P, and an internal gear 312R arranged around the multiple planetary gears 312P.

[0073] The second planetary gear mechanism 32 has a sun gear 32S, a plurality of planetary gears 32P arranged around the sun gear 32S, a second carrier 32C that supports the plurality of planetary gears 32P, and an internal gear 32R arranged around the plurality of planetary gears 32P.

[0074] The third planetary gear mechanism 33 has a sun gear 33S, a plurality of planetary gears 33P arranged around the sun gear 33S, a third carrier 33C that supports the plurality of planetary gears 33P, and an internal gear 33R arranged around the plurality of planetary gears 33P.

[0075] The spindle 81 is connected to the third carrier 33C via a spindle lock mechanism 50. The spindle lock mechanism 50 has a lock cam 51 arranged around the spindle 81 and a lock ring 52 that rotatably supports the lock cam 51. The lock ring 52 is arranged inside the second casing 4B. The lock ring 52 is fixed to the second casing 4B. Rotation of the third carrier 33C rotates the spindle 81.

[0076] The spindle 81 is rotatably supported by a bearing 83 and a bearing 84. While being supported by the bearings 83 and 84, the spindle 81 is movable in the front-rear direction.

[0077] The spindle 81 has a flange portion 81F. A coil spring 87 is disposed between the flange portion 81F and the bearing 83. The flange portion 81F contacts the front end portion of the coil spring 87. The coil spring 87 generates an elastic force that moves the spindle 81 forward.

[0078] The chuck 82 is capable of holding a tool bit. The chuck 82 is connected to the front part of the spindle 81. A screw hole 81R is provided in the front end part of the spindle 81. When the spindle 81 rotates, the chuck 82 rotates. The chuck 82 rotates while holding the tool bit.

[0079] The first cam 41 and the second cam 42 of the vibration mechanism 40 are disposed inside the second casing 4B. In the front-rear direction, the first cam 41 and the second cam 42 are disposed between the bearing 83 and the bearing 84.

[0080] The first cam 41 is ring-shaped. The first cam 41 is arranged around the spindle 81. The first cam 41 is fixed to the spindle 81. The first cam 41 rotates together with the spindle 81. Cam teeth are provided on the rear surface of the first cam 41. The first cam 41 is supported by a stop ring 44. The stop ring 44 is arranged around the spindle 81. In the front-rear direction, the stop ring 44 is arranged between the first cam 41 and the bearing 83.

[0081] The second cam 42 is ring-shaped. The second cam 42 is disposed behind the first cam 41. The second cam 42 is disposed around the spindle 81. The second cam 42 is rotatable relative to the spindle 81. Cam teeth are provided on the front surface of the second cam 42. The cam teeth on the front surface of the second cam 42 mesh with the cam teeth on the rear surface of the first cam 41. A pawl is provided on the rear surface of the second cam 42.

[0082] A support ring 45 is disposed between the second cam 42 and the bearing 84 in the front-rear direction. The support ring 45 is disposed inside the second casing 4B. The support ring 45 is fixed to the second casing 4B. A plurality of steel balls 46 are disposed on the front surface of the support ring 45. A washer 47 is disposed between the steel balls 46 and the second cam 42. The second cam 42 is rotatable in the space defined by the support ring 45 and the washer 47 while its front-rear movement is restricted.

[0083] The vibration switching ring 43 switches between vibration mode and non-vibration mode. The mode switching ring 13 is connected to the vibration switching ring 43 via a cam ring 48. The mode switching ring 13 and the cam ring 48 are rotatable together. The vibration switching ring 43 is movable in the front-rear direction. The vibration switching ring 43 has a protrusion 43T. The protrusion 43T is inserted into a guide hole provided in the second casing 4B. The vibration switching ring 43 is movable in the front-rear direction while being guided by the guide hole provided in the second casing 4B. The protrusion 43T restricts the rotation of the vibration switching ring 43. When the mode switching ring 13 is operated by an operator, the vibration switching ring 43 moves in the front-rear direction. The vibration switching ring 43 switches between vibration mode and non-vibration mode by moving in the front-rear direction between a forward position and a retracted position further rearward than the forward position. By operating the mode switching ring 13, the vibration mode and the non-vibration mode can be switched.

[0084] The vibration mode includes a state in which rotation of the second cam 42 is restricted. The non-vibration mode includes a state in which rotation of the second cam 42 is permitted. When the vibration switching ring 43 moves to the forward position, rotation of the second cam 42 is restricted. When the vibration switching ring 43 moves to the backward position, rotation of the second cam 42 is permitted.

[0085] In the vibration mode, at least a portion of the vibration switching ring 43 that has moved to the forward position comes into contact with the second cam 42. The contact between the vibration switching ring 43 and the second cam 42 restricts the rotation of the second cam 42. When the motor 6 is driven while the rotation of the second cam 42 is restricted, the first cam 41 fixed to the spindle 81 rotates while contacting the cam teeth of the second cam 42. As a result, the spindle 81 rotates while vibrating in the front-to-rear direction.

[0086] In the non-vibration mode, the vibration switching ring 43, which has moved to the retracted position, moves away from the second cam 42. The movement of the vibration switching ring 43 away from the second cam 42 allows the second cam 42 to rotate. When the motor 6 is driven while the rotation of the second cam 42 is allowed, the second cam 42 rotates together with the first cam 41 and the spindle 81. This allows the spindle 81 to rotate in the front-to-rear direction without vibrating.

[0087] The vibration switching ring 43 is disposed around the first cam 41 and the second cam 42. The vibration switching ring 43 also has a facing portion 43S that faces the rear surface of the second cam 42. The facing portion 43S protrudes radially inward from the rear portion of the vibration switching ring 43.

[0088] When the mode switching ring 13 is operated and the vibration switching ring 43 moves to the forward position, the claw on the rear surface of the second cam 42 comes into contact with the opposing portion 43S of the vibration switching ring 43. This restricts the rotation of the second cam 42. In this way, when the mode switching ring 13 is operated and the vibration switching ring 43 moves to the forward position, the vibration mechanism 40 is switched to the vibration mode.

[0089] When the mode switching ring 13 is operated and the vibration switching ring 43 moves to the retracted position, the opposing portion 43S of the vibration switching ring 43 moves away from the second cam 42. This allows the second cam 42 to rotate. In this way, when the mode switching ring 13 is operated and the vibration switching ring 43 moves to the retracted position, the vibration mechanism 40 is switched to the non-vibration mode.

[0090] <Deceleration mechanism> Fig. 6 is a front perspective view showing a portion of the driver drill 1 according to the embodiment. Fig. 7 is a front view showing a portion of the driver drill 1 according to the embodiment. Fig. 8 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, which corresponds to the cross-sectional view taken along line AA in Fig. 7. Fig. 9 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, which corresponds to the cross-sectional view taken along line DD in Fig. 7. Fig. 10 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, which corresponds to the cross-sectional view taken along line RR in Fig. 7.

[0091] The casing 4 houses the power transmission mechanism 7. The casing 4 includes a first casing 4A, a second casing 4B, a bracket plate 4C, and a stop plate 4D. The second casing 4B is disposed in front of the first casing 4A. The speed change lever 12 is disposed above the first casing 4A. The mode change ring 13 is disposed in front of the second casing 4B.

[0092] The first casing 4A is fixed to the rear end of the second casing 4B. The bracket plate 4C is arranged to cover the opening at the rear end of the first casing 4A. The bracket plate 4C is fixed to the rear end of the first casing 4A with screws 4E. The stop plate 4D is arranged to cover the opening at the front end of the second casing 4B. The stop plate 4D is fixed to the front end of the second casing 4B with screws 4F.

[0093] As described with reference to FIG. 5, pinion gear 31S includes large diameter portion 311S and small diameter portion 312S disposed forward of large diameter portion 311S.

[0094] The first planetary gear mechanism 31 has a planetary gear 311P, a planetary gear 312P arranged forward of the planetary gear 311P, a first carrier 31C supporting each of the multiple planetary gears 311P and the multiple planetary gears 312P, an internal gear 311R arranged around the multiple planetary gears 311P, and an internal gear 312R arranged around the multiple planetary gears 312P.

[0095] A plurality of planetary gears 311P (first planetary gears) are arranged around the large diameter portion 311S of the pinion gear 31S. A plurality of planetary gears 312P (second planetary gears) are arranged around the small diameter portion 312S of the pinion gear 31S. The first carrier 31C supports each of the plurality of planetary gears 311P and the plurality of planetary gears 312P. The internal gear 311R (first internal gear) is arranged around the plurality of planetary gears 311P. The internal gear 312R (second internal gear) is arranged around the plurality of planetary gears 312P. The outer diameter of the planetary gear 311P is smaller than the outer diameter of the planetary gear 312P. A pin 31A is provided on the first carrier 31C. Planetary gears 311P and 312P are rotatably supported by pins 31 A. First carrier 31C rotatably supports planetary gears 311P and 312P via pins 31 A. Gears are provided on the outer periphery of first carrier 31C.

[0096] The second planetary gear mechanism 32 has a sun gear 32S, a plurality of planetary gears 32P arranged around the sun gear 32S, a second carrier 32C supporting the plurality of planetary gears 32P, and an internal gear 32R arranged around the plurality of planetary gears 32P. The sun gear 32S is arranged in front of the first carrier 31C. The diameter of the sun gear 32S is smaller than the diameter of the first carrier 31C. The first carrier 31C and the sun gear 32S are integral. The first carrier 31C and the sun gear 32S rotate together. A pin 32A is provided on the second carrier 32C. The planetary gear 32P is rotatably supported by the pin 32A. The second carrier 32C rotatably supports the planetary gear 32P via the pin 32A.

[0097] The third planetary gear mechanism 33 includes a sun gear 33S, a plurality of planetary gears 33P arranged around the sun gear 33S, a third carrier 33C supporting the plurality of planetary gears 33P, and an internal gear 33R arranged around the plurality of planetary gears 33P. The sun gear 33S is arranged in front of the second carrier 32C. The diameter of the sun gear 33S is smaller than the diameter of the second carrier 32C. The second carrier 32C and the sun gear 33S are integral. The second carrier 32C and the sun gear 33S rotate together. A pin 33A is provided on the third carrier 33C. The planetary gear 33P is rotatably supported by the pin 33A. The third carrier 33C rotatably supports the planetary gear 33P via the pin 33A.

[0098] Fig. 11 is a cross-sectional view showing the reduction mechanism 30 according to the embodiment, and corresponds to a cross-sectional view taken along line CC in Fig. 8. Fig. 12 is a perspective view of the reduction mechanism 30 according to the embodiment, seen from the front right. Fig. 13 is a perspective view of the reduction mechanism 30 according to the embodiment, seen from the front left.

[0099] As shown in FIGS. 8, 9, 10, 11, and 12, the speed reduction mechanism 30 has a first speed switching mechanism 71 and a second speed switching mechanism 72.

[0100] The first speed switching mechanism 71 switches between a first deceleration mode in which rotation of the internal gear 312R of the first planetary gear mechanism 31 is prevented and rotation of the internal gear 311R is allowed, and a second deceleration mode in which rotation of the internal gear 311R of the first planetary gear mechanism 31 is prevented and rotation of the internal gear 312R is allowed.

[0101] The first speed change mechanism 71 has an annular member 35 and a cam pin 250.

[0102] The annular member 35 is connected to the cam pin 250. The annular member 35 is movable in the front-rear direction inside the first casing 4A. When the annular member 35 moves forward, the first deceleration mode is entered, and when the annular member 35 moves backward, the second deceleration mode is entered.

[0103] In the embodiment, the reduction ratio of the rear stage (first stage) of the first planetary gear mechanism 31 consisting of the planetary gear 311P and the internal gear 311R is different from the reduction ratio of the front stage (second stage) of the first planetary gear mechanism 31 consisting of the planetary gear 312P and the internal gear 312R. The reduction ratio of the front stage consisting of the planetary gear 312P and the internal gear 312R is greater than the reduction ratio of the rear stage consisting of the planetary gear 311P and the internal gear 311R. When the pinion gear 31S rotates at a constant rotation speed, the rotation speed of the first carrier 31C in the first deceleration mode is slower than the rotation speed of the first carrier 31C in the second deceleration mode.

[0104] The annular member 35 includes a wire disposed around at least one of the internal gears 311R and 312R. An upper portion of the annular member 35 is fixed to a lever member 37. The lever member 37 is connected to the speed selector lever 12. The lever member 37 is guided in the front-rear direction by a guide rod 38. The guide rod 38 is fixed to at least a portion of the first casing 4A. In the embodiment, the rear end portion of the guide rod 38 is fixed to the bracket plate 4C. A coil spring 39 is supported on the guide rod 38. The rear end portion of the coil spring 39 is supported on the bracket plate 4C. The front end portion of the coil spring 39 is connected to the lever member 37. The coil spring 39 biases the annular member 35 forward via the lever member 37.

[0105] The cam pin 250 is hooked onto the annular member 35. The cam pin 250 has a groove 250A in which the annular member 35 is disposed. A plurality of cam pins 250 are provided. The internal gear 311R and the internal gear 312R are each housed in the first casing 4A. As shown in FIG. 11 , a guide groove 4G that guides the cam pin 250 is provided on the inner surface of the first casing 4A. The cam pin 250 is disposed in the guide groove 4G of the first casing 4A. The guide groove 4G is long in the front-rear direction. The cam pin 250 can move in the front-rear direction while being guided by the guide groove 4G. Because the cam pin 250 is disposed in the guide groove 4G, it does not move in the circumferential direction.

[0106] A plurality of cam teeth 311F are provided on the outer peripheral surface of the internal gear 311R. A plurality of cam teeth 312F are provided on the outer peripheral surface of the internal gear 312R. The cam pin 250 is a contact member that comes into contact with either the cam teeth 311F of the internal gear 311R or the cam teeth 312F of the internal gear 312R. The cam pin 250 is guided by the guide groove 4G and moves between a position facing the outer peripheral surface of the internal gear 311R and a position facing the outer peripheral surface of the internal gear 312R. Contact between the cam teeth 311F and the cam pin 250 prevents rotation of the internal gear 311R. Contact between the cam teeth 312F and the cam pin 250 prevents rotation of the internal gear 312R.

[0107] The annular member 35 is connected to the speed selector lever 12. When the speed selector lever 12 is operated to move in the front-rear direction, the annular member 35 moves in the front-rear direction. When the annular member 35 moves in the front-rear direction, the cam pin 250 moves in the front-rear direction together with the annular member 35.

[0108] When the annular member 35 moves forward and is positioned around the internal gear 312R, and the cam pin 250 is positioned to face the outer circumferential surface of the internal gear 312R, the cam teeth 312F come into contact with the cam pin 250. This prevents the internal gear 312R from rotating. In other words, when the annular member 35 moves forward and prevents the internal gear 312R from rotating, the first planetary gear mechanism 31 enters the first deceleration mode.

[0109] When the annular member 35 moves rearward and is disposed around the internal gear 311R, and the cam pin 250 is disposed so as to face the outer circumferential surface of the internal gear 311R, the cam teeth 311F come into contact with the cam pin 250. This prevents the internal gear 311R from rotating. In other words, when the annular member 35 moves rearward and prevents the internal gear 311R from rotating, the first planetary gear mechanism 31 enters the second reduction mode.

[0110] The second speed switching mechanism 72 switches between an enabled mode in which the speed reduction function of the second planetary gear mechanism 32 is enabled, and a disabled mode in which the speed reduction function of the second planetary gear mechanism 32 is disabled. Placing the second planetary gear mechanism 32 in the enabled mode includes preventing rotation of the internal gear 32R. Placing the second planetary gear mechanism 32 in the disabled mode includes allowing rotation of the internal gear 32R. By preventing rotation of the internal gear 32R, the second planetary gear mechanism 32 is in the enabled mode. By allowing rotation of the internal gear 32R, the second planetary gear mechanism 32 is in the disabled mode.

[0111] The second speed change mechanism 72 has a speed change member 34 connected to the speed change lever 12 and the internal gear 32R, respectively, and a cam ring 36 into which the internal gear 32R is inserted to prevent rotation of the internal gear 32R.

[0112] The speed switching member 34 is movable in the front-rear direction inside the first casing 4 A. When the speed switching member 34 moves forward, the active mode is established, and when the speed switching member 34 moves backward, the inactive mode is established.

[0113] The speed switching member 34 has a ring portion 34A, a slider portion 34B, and a lever portion 34C. The ring portion 34A is disposed around the internal gear 32R. The ring portion 34A is connected to the internal gear 32R via a pin 34D. A recess 32D into which the pin 34D is inserted is provided on the outer peripheral surface of the internal gear 32R. The ring portion 34A and the internal gear 32R are connected by inserting the pin 34D into the recess 32D of the internal gear 32R. The slider portion 34B is disposed so as to extend rearward from the ring portion 34A. A plurality of slider portions 34B are provided at intervals in the circumferential direction. The slider portions 34B are guided in the front-rear direction by a guide groove provided on the inner surface of the first casing 4A. The lever portion 34C is provided on the upper portion of the ring portion 34A. Lever portion 34C is connected to speed change lever 12. Lever portion 34C has a protrusion 34E that protrudes upward from the top surface of lever portion 34C. Coil spring 34F is arranged in front of protrusion 34E. Coil spring 34G is arranged behind protrusion 34E. The front end of coil spring 34F is supported by at least a portion of first casing 4A. The rear end of coil spring 34F is connected to protrusion 34E. The rear end of coil spring 34G is supported by at least a portion of speed change lever 12. The front end of coil spring 34G is connected to protrusion 34E. Coil spring 34F urges speed change member 34 rearward. Coil spring 34G urges speed change member 34 forward.

[0114] The cam ring 36 is disposed in front of the internal gear 32R. The cam ring 36 is fixed to the first casing 4A. Cam teeth are provided on the inner peripheral surface of the cam ring 36. A plurality of the cam teeth are provided at intervals in the circumferential direction. Cam teeth 32F are provided on the outer peripheral surface of the internal gear 32R. The cam teeth 32F can mesh with the cam teeth of the cam ring 36.

[0115] When the speed switching lever 12 is operated to move in the front-rear direction, the speed switching member 34 moves in the front-rear direction. When the speed switching member 34 moves in the front-rear direction, the internal gear 32R, which is connected to the ring portion 34A via the pin 34D, moves in the front-rear direction. When the internal gear 32R moves in the front-rear direction, the internal gear 32R switches between a state in which it is inserted into the cam ring 36 and a state in which it is removed from the cam ring 36.

[0116] The internal gear 32R moves forward, and at least a portion of the internal gear 32R is inserted inside the cam ring 36, and the cam teeth of the cam ring 36 mesh with the cam teeth 32F of the internal gear 32R, thereby preventing rotation of the internal gear 32R. In other words, the speed switching member 34 moves forward, preventing rotation of the internal gear 32R, and the second planetary gear mechanism 32 enters the effective mode.

[0117] The internal gear 32R moves rearward, the internal gear 32R is removed from the inside of the cam ring 36, and the cam teeth of the cam ring 36 and the cam teeth 32F of the internal gear 32R are separated, thereby allowing the internal gear 32R to rotate. In other words, the speed switching member 34 moves rearward, allowing the internal gear 32R to rotate, and the second planetary gear mechanism 32 enters the disabled mode.

[0118] When the second planetary gear mechanism 32 is in the active mode, the internal gear 32R meshes only with the planetary gear 32P. When the second planetary gear mechanism 32 is in the inactive mode, the internal gear 32R meshes with both the planetary gear 32P and the first carrier 31C.

[0119] As described above, in the embodiment, the speed modes of the reduction mechanism 30 include a low speed mode, a medium speed mode, and a high speed mode.

[0120] The movable range of the speed switch lever 12 is defined in the front-to-rear direction. When the speed switch lever 12 is operated to move to the front of the movable range, the speed mode of the reduction mechanism 30 is set to low-speed mode. When the speed switch lever 12 is operated to move to the middle of the movable range, the speed mode of the reduction mechanism 30 is set to medium-speed mode. When the speed switch lever 12 is operated to move to the rear of the movable range, the speed mode of the reduction mechanism 30 is set to high-speed mode.

[0121] The low speed mode includes the first planetary gear mechanism 31 being set to the first deceleration mode and the second planetary gear mechanism 32 being set to the active mode. When the speed selector lever 12 is operated to move to the front of its movable range, the first planetary gear mechanism 31 is set to the first deceleration mode and the second planetary gear mechanism 32 is set to the active mode.

[0122] The medium speed mode includes a state in which the first planetary gear mechanism 31 is set to the first deceleration mode and the second planetary gear mechanism 32 is set to the disabled mode. When the speed selector lever 12 is operated to move to the middle of its movable range, the first planetary gear mechanism 31 is set to the first deceleration mode and the second planetary gear mechanism 32 is set to the disabled mode.

[0123] The high-speed mode includes the first planetary gear mechanism 31 being set to the second deceleration mode and the second planetary gear mechanism 32 being set to the disabled mode. When the speed selector lever 12 is operated to move to the rear of its movable range, the first planetary gear mechanism 31 is set to the second deceleration mode and the second planetary gear mechanism 32 is set to the disabled mode.

[0124] Each of Figures 6 to 13 shows a state in which the speed reduction mechanism 30 is set to the low speed mode.

[0125] Fig. 14 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, and corresponds to the cross-sectional view taken along line AA in Fig. 7. Fig. 15 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, and corresponds to the cross-sectional view taken along line DD in Fig. 7. Fig. 16 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, and corresponds to the cross-sectional view taken along line RR in Fig. 7. Figs. 14 to 16 show a state in which the reduction mechanism 30 is set to the medium speed mode.

[0126] The speed switch lever 12 is moved to the middle portion of its movable range so that the reduction gear mechanism 30 is in the medium speed mode. When the speed switch lever 12 is moved to the middle portion, the lever portion 34C moves rearward due to the biasing force of the coil spring 34F. This causes the speed switch member 34 to move rearward. As the speed switch member 34 moves rearward, the internal gear 32R, which is connected to the ring portion 34A via the pin 34D, moves rearward. As the internal gear 32R moves rearward, it is disengaged from the cam ring 36 and meshes with both the planetary gear 32P and the first carrier 31C.

[0127] When the speed selector lever 12 is positioned in the middle of its movable range, the annular member 35 remains positioned around the internal gear 312R. In the first planetary gear mechanism 31, rotation of the internal gear 312R is prevented, and rotation of the internal gear 311R is permitted.

[0128] Fig. 17 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, and corresponds to the cross-sectional view taken along line AA in Fig. 7. Fig. 18 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, and corresponds to the cross-sectional view taken along line DD in Fig. 7. Fig. 19 is a cross-sectional view showing the power transmission mechanism 7 according to the embodiment, and corresponds to the cross-sectional view taken along line RR in Fig. 7. Figs. 14 to 16 show a state in which the reduction mechanism 30 is set to high-speed mode.

[0129] The speed selector lever 12 is moved to the rear of its movable range so that the reduction gear mechanism 30 is in the high-speed mode. When the speed selector lever 12 is moved to the rear, the lever member 37 is moved rearward while being guided by the guide rod 38. As the lever member 37 moves rearward, the annular member 35 moves rearward together with the cam pin 250. As a result, the annular member 35 is positioned around the internal gear 311R. Furthermore, the cam pin 250 comes into contact with the cam teeth 311F provided on the outer peripheral surface of the internal gear 311R. This prevents the internal gear 311R from rotating. As the cam pin 250 moves rearward, the cam pin 250 separates from the cam teeth 312F provided on the outer peripheral surface of the internal gear 312R. This allows the internal gear 312R to rotate.

[0130] When the speed change lever 12 is positioned at the rear of its movable range, the internal gear 32R of the second planetary gear mechanism 32 is allowed to rotate.

[0131] <Operation of the reduction mechanism> When the motor 6 is driven to rotate the rotor shaft 63 while the reduction gear 30 is in the low-speed mode, the pinion gear 31S rotates, causing the planetary gear 312P to revolve around the small diameter portion 312S of the pinion gear 31S. The revolution of the planetary gear 312P causes the first carrier 31C and the sun gear 32S to rotate at a rotational speed lower than the rotational speed of the rotor shaft 63. The rotation of the sun gear 32S causes the planetary gear 32P to revolve around the sun gear 32S. The revolution of the planetary gear 32P causes the second carrier 32C and the sun gear 33S to rotate at a rotational speed lower than the rotational speed of the first carrier 31C. In this way, when the internal gear 32R is positioned in the low-speed mode position and the motor 6 is driven, both the deceleration function of the first planetary gear mechanism 31 and the deceleration function of the second planetary gear mechanism 32 are exerted, and the second carrier 32C and the sun gear 33S rotate in low-speed mode.

[0132] When the motor 6 is driven to rotate the rotor shaft 63 while the reduction gear 30 is set to the medium speed mode, the pinion gear 31S rotates, causing the planetary gear 312P to revolve around the small diameter portion 312S of the pinion gear 31S. The revolution of the planetary gear 312P causes the first carrier 31C and the sun gear 32S to rotate at a rotational speed lower than the rotational speed of the rotor shaft 63. The internal gear 32R meshes with both the planetary gear 32P and the first carrier 31C, so the internal gear 32R and the first carrier 31C rotate together. The rotation of the internal gear 32R causes the planetary gear 32P to revolve at the same orbital speed as the rotational speed of the internal gear 32R. Due to the revolution of planetary gear 32P, second carrier 32C and sun gear 33S rotate at the same rotational speed as first carrier 31C. In this way, when motor 6 is driven in a state in which second planetary gear mechanism 32 is set to the disabled mode, the speed reduction function of first planetary gear mechanism 31 is exerted but the speed reduction function of second planetary gear mechanism 32 is not exerted, and second carrier 32C and sun gear 33S rotate in the medium speed mode.

[0133] When the motor 6 is driven to rotate the rotor shaft 63 while the reduction gear 30 is set to the high-speed mode, the pinion gear 31S rotates, causing the planetary gear 311P to revolve around the large-diameter portion 311S of the pinion gear 31S. The revolution of the planetary gear 311P causes the first carrier 31C and the sun gear 32S to rotate at a rotational speed lower than the rotational speed of the rotor shaft 63. The internal gear 32R meshes with both the planetary gear 32P and the first carrier 31C, so the internal gear 32R and the first carrier 31C rotate together. The rotation of the internal gear 32R causes the planetary gear 32P to revolve at the same orbital speed as the rotational speed of the internal gear 32R. Due to the revolution of planetary gear 32P, second carrier 32C and sun gear 33S rotate at the same rotational speed as first carrier 31C. In this way, when motor 6 is driven in a state in which second planetary gear mechanism 32 is set to the disabled mode, the speed reduction function of first planetary gear mechanism 31 is exerted but the speed reduction function of second planetary gear mechanism 32 is not exerted, and second carrier 32C and sun gear 33S rotate in high-speed mode.

[0134] When second carrier 32C and sun gear 33S rotate, planetary gear 33P revolves around sun gear 33S. The revolution of planetary gear 33P rotates third carrier 33C. The rotation of third carrier 33C rotates spindle 81.

[0135] <Effects> As described above, in the embodiment, the driver drill 1 includes a motor 6, a first planetary gear mechanism 31, and a second planetary gear mechanism 32. The first planetary gear mechanism 31 has a rear stage including a plurality of planetary gears 311P arranged around a pinion gear 31S rotated by the motor 6 and an internal gear 311R arranged around the plurality of planetary gears 311P, and a front stage including a plurality of planetary gears 312P arranged around the pinion gear 31S and an internal gear 312R arranged around the plurality of planetary gears 312P. The reduction ratio of the rear stage is different from that of the front stage. The second planetary gear mechanism 32 is arranged forward of the first planetary gear mechanism 31 and is actuated by the rotational force of the first planetary gear mechanism 31. The driver drill 1 also includes a spindle 81 that rotates by the rotational force of the motor 6 transmitted via the second planetary gear mechanism 32. The driver drill 1 also includes a first speed switching mechanism 71 that switches between a first deceleration mode in which rotation of the internal gear 312R is prevented but rotation of the internal gear 311R is permitted, and a second deceleration mode in which rotation of the internal gear 311R is prevented but rotation of the internal gear 312R is permitted. The driver drill 1 also includes a second speed switching mechanism 72 that switches between an effective mode in which rotation of the internal gear 32R of the second planetary gear mechanism 32 is prevented, and an ineffective mode in which rotation of the internal gear 32R is permitted.

[0136] In the above configuration, the first planetary gear mechanism 31 has a rear stage and a front stage. The reduction ratio of the rear stage is different from that of the front stage. The first planetary gear mechanism 31 is switched to one of the first and second reduction modes, and the second planetary gear mechanism 32 is switched to one of the enabled and disabled modes, thereby switching the speed mode of the driver drill 1 among a low-speed mode, a medium-speed mode, and a high-speed mode. This allows the operator to set the driver drill 1 to an appropriate speed mode depending on the type of work being performed.

[0137] In the embodiment, the pinion gear 31S includes a large diameter portion 311S and a small diameter portion 312S disposed forward of the large diameter portion 311S. The plurality of planetary gears 311P are disposed around the large diameter portion 311S. The plurality of planetary gears 312P are disposed around the small diameter portion 312S.

[0138] In the above configuration, the pinion gear 31S has the large diameter portion 311S and the small diameter portion 312S, so that a difference can be generated between the reduction ratio of the rear stage and the reduction ratio of the front stage.

[0139] In this embodiment, cam teeth 311F are provided on the outer peripheral surface of the internal gear 311R, and cam teeth 312F are provided on the outer peripheral surface of the internal gear 312R. The first speed switching mechanism 71 has a cam pin 250 that comes into contact with either the cam teeth 311F of the internal gear 311R or the cam teeth 312F of the internal gear 312R.

[0140] In the above configuration, the cam pin 250 comes into contact with the cam teeth 311F of the internal gear 311R, thereby preventing rotation of the internal gear 311R. The cam pin 250 comes into contact with the cam teeth 312F of the internal gear 312R, thereby preventing rotation of the internal gear 312R.

[0141] In this embodiment, the internal gear 311R and the internal gear 312R are each housed in a casing 4. The casing 4 has a guide groove 4G that guides the cam pin 250. The cam pin 250 moves, while being guided by the guide groove 4G, between a position facing the outer circumferential surface of the internal gear 311R and a position facing the outer circumferential surface of the internal gear 312R.

[0142] In the above configuration, the cam pin 250 can move smoothly in the front-rear direction while being guided by the guide groove 4G. Furthermore, by being disposed in the guide groove 4G, the cam pin 250 is prevented from moving in the circumferential direction.

[0143] In the embodiment, the first speed switching mechanism 71 has an annular member 35 that is connected to the cam pin 250 and is arranged around at least one of the internal gear 311R and the internal gear 312R. When the annular member 35 moves in the front-rear direction, the cam pin 250 moves.

[0144] In the above configuration, when a plurality of cam pins 250 are provided at intervals in the circumferential direction, the annular member 35 is connected to each of the plurality of cam pins 250. When the annular member 35 is moved, each of the plurality of cam pins 250 is moved simultaneously.

[0145] In the embodiment, the driver drill 1 includes a speed change lever 12 connected to an annular member 35. When the speed change lever 12 is operated to move in the forward and backward directions, the annular member 35 moves.

[0146] In the above configuration, the speed mode is switched by operating the speed change lever 12 in the forward and backward directions.

[0147] In this embodiment, the second speed change mechanism 72 has a speed change member 34 connected to the speed change lever 12 and the internal gear 32R of the second planetary gear mechanism 32, and a cam ring 36 into which the internal gear 32R is inserted to prevent rotation of the internal gear 32R. By operating the speed change lever 12 to move forward or backward, the internal gear 32R is switched between a state in which it is inserted into the cam ring 36 and a state in which it is removed from the cam ring 36.

[0148] In the above configuration, the speed mode is switched by operating the speed change lever 12 in the forward and backward directions.

[0149] In this embodiment, the motor 6 includes a stator 61 and a rotor 62 that includes a rotor shaft 63 and rotates relative to the stator 61. The pinion gear 31S is provided at the front end of the rotor shaft 63.

[0150] In the above configuration, the rotational force of the rotor shaft 63 is transmitted directly to the first planetary gear mechanism 31.

[0151] In this embodiment, the driver drill 1 includes a third planetary gear mechanism 33 that is disposed forward of the second planetary gear mechanism 32 and is actuated by the rotational force of the second planetary gear mechanism 32. The spindle 81 is connected to the third planetary gear mechanism 33.

[0152] In the above configuration, the rotation speed of the spindle 81 is reduced by the third planetary gear mechanism 33.

[0153] [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.

[0154] <Deceleration mechanism> Fig. 20 is a front perspective view showing a portion of the driver drill 1 according to the embodiment. As shown in Fig. 20, the casing 400 includes a first casing 400A, a second casing 400B disposed in front of the first casing 400A, a bracket plate 400C disposed at the rear end of the first casing 400A, and a stop plate 400D disposed at the front end of the second casing 400B. A mode switching ring 130 is disposed in front of the second casing 400B.

[0155] In the above-described embodiment, the speed mode of the reduction mechanism 30 is changed by operating the speed switch lever 12, which is movable in the front-rear direction. In the second embodiment, the speed mode of the reduction mechanism 300 is changed by operating the speed switch lever 120, which is movable in the circumferential direction. The reduction mechanism 300 is set to the low-speed mode by moving the speed switch lever 120 to the left part of the movable range of the speed switch lever 120. The reduction mechanism 300 is set to the medium-speed mode by moving the speed switch lever 120 to the middle part of the movable range of the speed switch lever 120. The reduction mechanism 300 is set to the high-speed mode by moving the speed switch lever 120 to the right part of the movable range of the speed switch lever 120.

[0156] Fig. 21 is a cross-sectional view showing the power transmission mechanism 700 according to the embodiment. Fig. 22 is a side view showing the power transmission mechanism 700 according to the embodiment. Fig. 21 and Fig. 22 each show a state in which the reduction mechanism 300 is set to the low-speed mode.

[0157] Fig. 23 is a cross-sectional view showing the power transmission mechanism 700 according to the embodiment. Fig. 24 is a side view showing the power transmission mechanism 700 according to the embodiment. Fig. 23 and Fig. 24 each show a state in which the reduction mechanism 300 is set to the medium speed mode.

[0158] Fig. 25 is a cross-sectional view showing the power transmission mechanism 700 according to the embodiment. Fig. 26 is a side view showing the power transmission mechanism 700 according to the embodiment. Fig. 25 and Fig. 26 each show a state in which the reduction mechanism 300 is set to the high-speed mode.

[0159] The reduction mechanism 300 has a first planetary gear mechanism 310 , a second planetary gear mechanism 320 , and a third planetary gear mechanism 33 .

[0160] The first planetary gear mechanism 310 has a plurality of planetary gears 310P, a first carrier 310C that rotatably supports each of the plurality of planetary gears 310P via pins 310A, and an internal gear 310R that is arranged around the plurality of planetary gears 310P. The plurality of planetary gears 310P are arranged around a sun gear (not shown) that is arranged at the front end of the rotor shaft 63.

[0161] The second planetary gear mechanism 320 includes a sun gear 320S, a plurality of planetary gears 320P arranged around the sun gear 320S, a second carrier 320C that rotatably supports each of the plurality of planetary gears 320P via pins 320A, and an internal gear 320R that is arranged around the plurality of planetary gears 320P. The sun gear 320S is arranged in front of the first carrier 310C. The diameter of the sun gear 320S is smaller than the diameter of the first carrier 310C. The first carrier 310C and the sun gear 320S are integral with each other. The first carrier 310C and the sun gear 320S rotate together.

[0162] The third planetary gear mechanism 330 includes a sun gear 330S, a plurality of planetary gears 330P arranged around the sun gear 330S, a third carrier 330C that rotatably supports each of the plurality of planetary gears 330P via pins 330A, and an internal gear 330R that is arranged around the plurality of planetary gears 330P. In this embodiment, the second carrier 320C and the sun gear 330S are separate bodies. A hole is formed in the center of the second carrier 320C. The second carrier 320C is ring-shaped. A gear is provided on the inner circumferential surface of the second carrier 320C. The rear portion of the sun gear 330S is inserted into the hole in the second carrier 320C and meshes with a gear provided on the inner circumferential surface of the second carrier 320C. Rotation of the second carrier 320C rotates the sun gear 330S. A front portion of the sun gear 330S is disposed in front of the second carrier 32C. A plurality of planetary gears 330P are disposed around the front portion of the sun gear 330S.

[0163] The internal gear 310R of the first planetary gear mechanism 310 is fixed to the first casing 400A. In each of the low-speed mode, medium-speed mode, and high-speed mode, the internal gear 310R does not rotate relative to the first casing 400A. In each of the low-speed mode, medium-speed mode, and high-speed mode, the speed reduction function of the first planetary gear mechanism 310 is always enabled.

[0164] The second planetary gear mechanism 320 is switched between an enabled mode in which the speed reduction function of the second planetary gear mechanism 320 is enabled and a disabled mode in which the speed reduction function of the second planetary gear mechanism 320 is disabled. Switching the second planetary gear mechanism 320 to the enabled mode includes preventing rotation of the internal gear 320R. Switching the second planetary gear mechanism 320 to the disabled mode includes allowing rotation of the internal gear 320R. By preventing rotation of the internal gear 320R, the second planetary gear mechanism 320 is switched to the enabled mode. By allowing rotation of the internal gear 320R, the second planetary gear mechanism 320 is switched to the disabled mode.

[0165] The third planetary gear mechanism 330 is switched between an enabled mode in which the speed reduction function of the third planetary gear mechanism 330 is enabled and a disabled mode in which the speed reduction function of the third planetary gear mechanism 330 is disabled. Switching the third planetary gear mechanism 330 to the enabled mode includes preventing rotation of the internal gear 330R. Switching the third planetary gear mechanism 330 to the disabled mode includes allowing rotation of the internal gear 330R. By preventing rotation of the internal gear 330R, the third planetary gear mechanism 330 is switched to the enabled mode. By allowing rotation of the internal gear 330R, the third planetary gear mechanism 330 is switched to the disabled mode.

[0166] In the embodiment, the reduction ratio of the second planetary gear mechanism 320 is greater than the reduction ratio of the third planetary gear mechanism 330 .

[0167] In the embodiment, the low speed mode includes the second planetary gear mechanism 320 being set to the enabled mode and the third planetary gear mechanism 330 being set to the enabled mode, i.e., the low speed mode includes a state in which rotation of both the internal gear 320R and the internal gear 330R is prevented.

[0168] The medium speed mode includes a state in which the second planetary gear mechanism 320 is set to the enabled mode and the third planetary gear mechanism 330 is set to the disabled mode. In other words, the medium speed mode includes a state in which the rotation of the internal gear 320R is prevented and the rotation of the internal gear 330R is allowed.

[0169] The high-speed mode includes a state in which the second planetary gear mechanism 320 is set to the disabled mode and the third planetary gear mechanism 330 is set to the enabled mode. In other words, the high-speed mode includes a state in which the internal gear 320R is allowed to rotate and the internal gear 330R is prevented from rotating.

[0170] As shown in FIGS. 21, 22, 23, 24, 25, and 26, the speed reduction mechanism 300 has a first movement mechanism 150 and a second movement mechanism 160.

[0171] The first movement mechanism 150 moves the internal gear 320R of the second planetary gear mechanism 320 in the front-to-rear direction. A cam ring 360 is fixed to the first casing 4A. The cam ring 360 is disposed in front of the internal gear 320R. Cam teeth are provided on the inner peripheral surface of the cam ring 360. A plurality of cam teeth are provided at intervals in the circumferential direction. Cam teeth 320F are provided on the outer peripheral surface of the internal gear 320R. The cam teeth 320F can mesh with the cam teeth of the cam ring 36.

[0172] The first movement mechanism 150 moves the internal gear 320R forward, and at least a portion of the internal gear 320R is inserted inside the cam ring 360, and the cam teeth of the cam ring 360 mesh with the cam teeth 320F of the internal gear 320R, thereby preventing rotation of the internal gear 320R. In other words, the first movement mechanism 150 moves the internal gear 320R forward, preventing rotation of the internal gear 320R, and thus the second planetary gear mechanism 320 enters the enabled mode.

[0173] The first movement mechanism 150 moves the internal gear 320R rearward, causing the internal gear 320R to be removed from the inside of the cam ring 360, and the cam teeth of the cam ring 360 and the cam teeth 320F of the internal gear 320R to separate, thereby allowing the internal gear 320R to rotate. In other words, the first movement mechanism 150 moves the internal gear 320R rearward, allowing the internal gear 320R to rotate, and the second planetary gear mechanism 320 enters the disabled mode.

[0174] When the second planetary gear mechanism 320 is in the enabled mode, the internal gear 320R meshes only with the planetary gear 320P. When the second planetary gear mechanism 320 is in the disabled mode, the internal gear 320R meshes with both the planetary gear 320P and the first carrier 310C.

[0175] The first movement mechanism 150 includes a speed switching member 340 and a cam ring 370 .

[0176] The speed switching member 340 is movable in the front-rear direction inside the first casing 4A. The speed switching member 340 is connected to the internal gear 320R. The speed switching member 340 has a ring portion 340A and a cam portion 340B. The ring portion 340A is disposed around the internal gear 320R. The cam portion 340B is fixed to a portion of the outer circumferential surface of the ring portion 340A. The speed switching member 340 is connected to the internal gear 320R via a pin 340D. A recess 320D is provided on the outer circumferential surface of the internal gear 320R, into which the pin 340D is inserted. The speed switching member 340 and the internal gear 320R are connected by inserting the pin 340D into the recess 320D of the internal gear 320R.

[0177] A coil spring 121 is connected to the speed switching member 340. The rear end of the coil spring 121 is supported by at least a part of the bracket plate 400C. The front end of the coil spring 121 is connected to the speed switching member 340. The coil spring 121 biases the speed switching member 340 forward.

[0178] Cam ring 370 is rotatably supported by casing 4. Cam ring 370 is connected to speed selector lever 120. Cam ring 370 is disposed around ring portion 340A. When speed selector lever 120 is operated to move in the rotational direction, cam ring 370 rotates together with speed selector lever 120.

[0179] Cam ring 370 has cam surface 371 that comes into contact with cam portion 340B. Cam ring 370 has recessed portion 372 in which cam portion 340B can be disposed. Cam surface 371 includes cam surface 371A provided at the rear end of cam ring 370 and cam surface 371B provided inside recessed portion 372. Speed ​​switching member 340 is urged forward by coil spring 121. Therefore, cam portion 340B is pressed against cam surface 371. As cam ring 370 rotates, the shape of cam surface 371 that comes into contact with cam portion 340B changes, causing cam portion 340B to move in the front-rear direction. As cam portion 340B moves in the front-rear direction, speed switching member 340 and internal gear 320R each move in the front-rear direction.

[0180] 22, when cam ring 370 rotates so that cam portion 340B contacts cam surface 371B of recess 372, speed switching member 340 and internal gear 320R move forward. When cam ring 360 rotates so that cam portion 340B contacts cam surface 371A, speed switching member 340 and internal gear 320R move backward.

[0181] The second movement mechanism 160 moves the internal gear 330R of the third planetary gear mechanism 330 in the front-rear direction. In this embodiment, the casing 400 includes a support plate 400E. The support plate 400E is fixed to the second casing 400B. The support plate 400E is disposed forward of the internal gear 330R. A rotation stop pin 124 is supported on the support plate 400E via a coil spring 123. A plurality of cam teeth 330F are provided on the outer peripheral surface of the internal gear 330R. The cam teeth 330F are capable of contacting the rotation stop pin 124. Contact between the cam teeth 330F and the rotation stop pin 124 prevents rotation of the internal gear 330R.

[0182] The internal gear 330R is moved forward by the second movement mechanism 160, and the cam tooth 330F comes into contact with the rotation stop pin 124, thereby preventing rotation of the internal gear 330R. In other words, the internal gear 330R is moved forward by the second movement mechanism 160, and the rotation of the internal gear 330R is prevented, so that the third planetary gear mechanism 330 enters the valid mode.

[0183] The second movement mechanism 160 moves the internal gear 330R rearward, and the cam tooth 330F and the rotation stop pin 124 separate, thereby allowing the internal gear 330R to rotate. In other words, the second movement mechanism 160 moves the internal gear 330R rearward, allowing the internal gear 330R to rotate, and the third planetary gear mechanism 330 enters the disabled mode.

[0184] When the third planetary gear mechanism 330 is in the enabled mode, the internal gear 330R meshes only with the planetary gear 330P. When the third planetary gear mechanism 330 is in the disabled mode, the internal gear 330R meshes with both the planetary gear 330P and the second carrier 320C.

[0185] The second movement mechanism 160 includes a speed switching member 350 and a cam ring 380 .

[0186] The speed switching member 350 comes into contact with the front surface of the internal gear 330R. The speed switching member 350 includes a pin that is positioned forward of the internal gear 330R. A coil spring 122 is connected to the speed switching member 350. The front end of the coil spring 122 is supported by at least a portion of the support plate 400E. The rear end of the coil spring 122 is connected to the speed switching member 350. The coil spring 122 urges the speed switching member 350 forward.

[0187] Cam ring 380 is rotatably supported by casing 4. Cam ring 380 is connected to speed selector lever 120. When speed selector lever 120 is operated to move in the rotational direction, cam ring 380 rotates together with speed selector lever 120.

[0188] A speed switching member 390 is disposed around the internal gear 330R. The speed switching member 390 has an annular plate portion 390A fixed to the outer circumferential surface of the internal gear 330R, and a cam portion 390B fixed to the annular plate portion 390A.

[0189] Cam ring 380 has cam surface 381 that contacts cam portion 390B. Cam ring 380 has recessed portion 382 in which cam portion 390B can be disposed. Cam surface 381 includes cam surface 381A provided at the front end of cam ring 380 and cam surface 381B provided inside recessed portion 382. Internal gear 330R is urged rearward by coil spring 122 via speed switching member 350. Therefore, cam portion 390B is pressed against cam surface 381. As cam ring 380 rotates, the shape of cam surface 381 that contacts cam portion 390B changes, causing cam portion 390B to move in the front-rear direction. As cam portion 390B moves in the front-rear direction, both speed switching member 390 and internal gear 330R move in the front-rear direction.

[0190] 22, when cam ring 380 rotates so that cam portion 390B contacts cam surface 381A, speed switching member 390 and internal gear 330R move forward. When cam ring 380 rotates so that cam portion 390B contacts cam surface 381A, speed switching member 390 and internal gear 330R move rearward.

[0191] As shown in Figures 23 and 24, when speed switch lever 120 is moved to the middle part of its movable range so that reduction mechanism 300 is in the medium speed mode, cam ring 380 rotates so that cam portion 390B is positioned in recessed portion 382 of cam ring 380. When cam ring 380 rotates so that cam portion 390B contacts cam surface 381B of recessed portion 382, ​​speed switch member 390 and internal gear 330R move forward. This places third planetary gear mechanism 33 in the inactive mode. When speed switch lever 120 is positioned in the middle part of its movable range, cam portion 340B is positioned in recessed portion 372 of cam ring 370. Therefore, second planetary gear mechanism 320 is in the active mode.

[0192] As shown in FIGS. 25 and 26 , when speed switch lever 120 is moved to the right side of its movable range so that reduction gear mechanism 300 is in the high-speed mode, cam ring 370 rotates so that cam portion 340B contacts cam surface 371A of cam ring 370 outside recess 372. As cam ring 370 rotates so that cam portion 340B contacts cam surface 371A, speed switch member 340 and internal gear 320R move rearward. This places second planetary gear mechanism 32 in the disable mode. Furthermore, when speed switch lever 120 is moved to the right side of its movable range so that reduction gear mechanism 300 is in the high-speed mode, cam ring 380 rotates so that cam portion 390B contacts cam surface 381A outside recess 382. As cam ring 380 rotates so that cam portion 390B contacts cam surface 381A, speed switch member 390 and internal gear 330R move forward. This puts the third planetary gear mechanism 33 into the effective mode.

[0193] <Effects> As described above, the speed mode of the reduction mechanism 300 can be switched among the low-speed mode, the medium-speed mode, and the high-speed mode, allowing the worker to set the reduction mechanism 300 to an appropriate speed mode depending on the type of work.

[0194] [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 will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0195] FIG. 27 is a front perspective view showing a portion of the driver drill 1 according to the embodiment. FIG. 28 is a side view showing a portion of the driver drill 1 according to the embodiment. FIG. 29 is a cross-sectional view showing a portion of the driver drill 1 according to the embodiment. As with the above-described embodiments, the driver drill 1 is an electric driver drill. As shown in FIGS. 27, 28, and 29, the casing 4 houses the power transmission mechanism 7. The casing 4 includes a first casing 4A, a second casing 4B, a bracket plate 4C, and a stop plate 4D. The second casing 4B is disposed in front of the first casing 4A. The mode switching ring 13 is disposed in front of the second casing 4B. The first casing 4A is made of synthetic resin. The second casing 4B is made of metal. In the embodiment, the second casing 4B is made of aluminum. The casing 4 is disposed in front of the motor accommodating portion 21. The first casing 4A and the second casing 4B are each cylindrical.

[0196] The first casing 4A is fixed to the rear end of the second casing 4B. The bracket plate 4C is arranged to cover the opening at the rear end of the first casing 4A. The bracket plate 4C is fixed to the rear end of the first casing 4A with screws 4E. The stop plate 4D is arranged to cover the opening at the front end of the second casing 4B. The stop plate 4D is fixed to the front end of the second casing 4B with screws 4F.

[0197] The power transmission mechanism 7 has a reduction mechanism 30. The reduction mechanism 30 has a first planetary gear mechanism 31, a second planetary gear mechanism 32, and a third planetary gear mechanism 33. At least a portion of the first planetary gear mechanism 31 is arranged forward of the motor 6. The second planetary gear mechanism 32 is arranged forward of the first planetary gear mechanism 31. The third planetary gear mechanism 33 is arranged forward of the second planetary gear mechanism 32. The first planetary gear mechanism 31 is operated by the rotational force of the motor 6. The second planetary gear mechanism 32 is operated by the rotational force of the first planetary gear mechanism 31. The third planetary gear mechanism 33 is operated by the rotational force of the second planetary gear mechanism 32. The first planetary gear mechanism 31 may also be referred to as a first planetary gear transmission mechanism. The second planetary gear mechanism 32 may also be referred to as a second planetary gear transmission mechanism. The third planetary gear mechanism 33 may also be referred to as a third planetary gear transmission mechanism.

[0198] The speed switch lever 12 is operated to change the speed mode of the reduction mechanism 30. The speed switch lever 12 is provided above the casing 4. The speed switch lever 12 is movable in the front-rear direction. The speed switch lever 12 is operated by an operator. The speed modes of the reduction mechanism 30 include a low-speed mode (first speed), a medium-speed mode (second speed), and a high-speed mode (third speed). When the speed switch lever 12 is operated to move to the front of its movable range, the speed mode of the reduction mechanism 30 is set to the low-speed mode (first speed). When the speed switch lever 12 is operated to move to the middle of its movable range, the speed mode of the reduction mechanism 30 is set to the medium-speed mode (second speed). When the speed switch lever 12 is operated to move to the rear of its movable range, the speed mode of the reduction mechanism 30 is set to the high-speed mode (third speed).

[0199] Fig. 30 is an exploded perspective view from the front showing the reduction mechanism 30 according to the embodiment. Fig. 31 is a perspective view from the rear showing a part of the reduction mechanism 30 according to the embodiment. Fig. 32 is a perspective cutaway view from the rear showing a part of the reduction mechanism 30 according to the embodiment.

[0200] The first planetary gear mechanism 31 includes a planetary gear 311P, a planetary gear 312P disposed forward of the planetary gear 311P, a first-stage carrier 311C supporting each of the planetary gears 311P and 312P, a second-stage carrier 312C supporting each of the planetary gears 312P, an internal gear 311R disposed around the planetary gears 311P, and an internal gear 312R disposed around the planetary gears 312P. Although not shown in FIGS. 30, 31, and 32, a pinion gear 31S is provided at the front end of the rotor shaft 63, as in the above-described embodiment. The pinion gear 31S functions as a sun gear of the first planetary gear mechanism 31. The pinion gear 31S is disposed on the front side of the stator 61. The pinion gear 31S may be rotated directly or indirectly by the rotor 62. The planetary gear 311P meshes with the pinion gear 31S. The internal gear 311R meshes with the planetary gear 311P.

[0201] The second planetary gear mechanism 32 has a sun gear 32S, a plurality of planetary gears 32P arranged around the sun gear 32S, a second carrier 32C supporting the plurality of planetary gears 32P, and an internal gear 32R arranged around the plurality of planetary gears 32P. The sun gear 32S is arranged forward of the internal gears 311R and 312R. The sun gear 32S may be rotated directly or indirectly by the planetary gears 311P and 312P. The planetary gear 32P meshes with the sun gear 32S. The internal gear 32R meshes with the planetary gear 32P.

[0202] The third planetary gear mechanism 33 has a sun gear 33S, a plurality of planetary gears 33P arranged around the sun gear 33S, a third carrier 33C that supports the plurality of planetary gears 33P, and an internal gear 33R arranged around the plurality of planetary gears 33P.

[0203] As in the above-described embodiment, a plurality of planetary gears 311P are arranged around the large diameter portion 311S of the pinion gear 31S, and a plurality of planetary gears 312P are arranged around the small diameter portion 312S of the pinion gear 31S.

[0204] The casing 4 (gear case) is disposed on the front side of the stator 61. The casing 4 houses the pinion gear 31S, the planetary gear 311P, the planetary gear 312P, the internal gear 311R, the internal gear 312R, the sun gear 32S, and the planetary gear 32P. As in the above-described embodiment, the spindle 81 is disposed on the front side of the internal gear 32R. The spindle 81 may be rotated directly or indirectly by the planetary gear 32P. A chuck 82 is fixed to the front of the spindle 81.

[0205] The planetary gear 311P is rotatably supported by first pins 311A. The first pins 311A ​​are supported by the first stage carrier 311C. The first pins 311A ​​protrude rearward from the rear surface of the first stage carrier 311C. A plurality of first pins 311A ​​are provided at intervals in the circumferential direction. In the embodiment, four first pins 311A ​​are provided at equal intervals in the circumferential direction. One planetary gear 311P is supported by each of the plurality (four) first pins 311A. The planetary gear 311P is disposed rearward of the first stage carrier 311C. The first stage carrier 311C rotatably supports the planetary gear 311P via the first pins 311A.

[0206] The planetary gear 312P is rotatably supported by the second pin 312A. The second pin 312A is supported by each of the first stage carrier 311C and the second stage carrier 312C. The first stage carrier 311C is disposed rearward of the second stage carrier 312C. A rear end of the second pin 312A is supported by the first stage carrier 311C. A front end of the second pin 312A is supported by the second stage carrier 312C. A plurality of second pins 312A are provided at intervals in the circumferential direction. In the embodiment, four second pins 312A are provided at equal intervals in the circumferential direction. The positions of the first pins 311A ​​and the second pins 312A are different in the circumferential direction. The second pin 312A is disposed between a pair of adjacent first pins 311A ​​in the circumferential direction. The planetary gears 312P are supported one by one by a plurality of (four) second pins 312A. In the front-rear direction (axial direction), the planetary gears 312P are disposed between the first stage carrier 311C and the second stage carrier 312C. Each of the first stage carrier 311C and the second stage carrier 312C rotatably supports the planetary gears 312P via the second pins 312A. A gear is provided on the outer periphery of the second stage carrier 312C.

[0207] The internal gear 311R is arranged around the plurality of planetary gears 311P. The internal gear 312R is arranged around the plurality of planetary gears 312P. The outer diameter of the planetary gear 311P is smaller than the outer diameter of the planetary gear 312P.

[0208] The second planetary gear mechanism 32 has a sun gear 32S, a plurality of planetary gears 32P arranged around the sun gear 32S, a second carrier 32C supporting the plurality of planetary gears 32P, and an internal gear 32R arranged around the plurality of planetary gears 32P. The sun gear 32S is arranged in front of the second-stage carrier 312C. The diameter of the sun gear 32S is smaller than the diameter of the second-stage carrier 312C. The second-stage carrier 312C and the sun gear 32S are integral. The second-stage carrier 312C and the sun gear 32S rotate together. A pin 32A is provided on the second carrier 32C. The planetary gear 32P is rotatably supported by the pin 32A. The second carrier 32C rotatably supports the planetary gear 32P via the pin 32A.

[0209] The third planetary gear mechanism 33 includes a sun gear 33S, a plurality of planetary gears 33P arranged around the sun gear 33S, a third carrier 33C supporting the plurality of planetary gears 33P, and an internal gear 33R arranged around the plurality of planetary gears 33P. The sun gear 33S is arranged in front of the second carrier 32C. The diameter of the sun gear 33S is smaller than the diameter of the second carrier 32C. The second carrier 32C and the sun gear 33S are integral. The second carrier 32C and the sun gear 33S rotate together. A pin 33A is provided on the third carrier 33C. The planetary gear 33P is rotatably supported by the pin 33A. The third carrier 33C rotatably supports the planetary gear 33P via the pin 33A.

[0210] Fig. 33 is a side view showing the first speed switching mechanism 71 and the second speed switching mechanism 72 according to the embodiment. Fig. 34 is a perspective view showing the first speed switching mechanism 71 and the second speed switching mechanism 72 according to the embodiment, viewed from the lower right rear. As in the above-described embodiment, the speed reduction mechanism 30 has the first speed switching mechanism 71 and the second speed switching mechanism 72.

[0211] The first speed switching mechanism 71 switches between a first deceleration mode in which rotation of the internal gear 312R of the first planetary gear mechanism 31 is prevented and rotation of the internal gear 311R is allowed, and a second deceleration mode in which rotation of the internal gear 311R of the first planetary gear mechanism 31 is prevented and rotation of the internal gear 312R is allowed.

[0212] The first speed switching mechanism 71 includes a change ring 500 , a first switching wire 510 , a first movable member 610 , and a first spring 630 .

[0213] The change ring 500 has a ring portion 500B and multiple protrusions 500C fixed to the ring portion 500B. The protrusions 500C are disposed in guide grooves provided on the inner circumferential surface of the first casing 4A. The guide grooves provided on the inner circumferential surface of the first casing 4A extend in the front-to-rear direction. By disposing the protrusions 500C in the guide grooves of the first casing 4A, relative rotation of the change ring 500 with respect to the first casing 4A is suppressed. The change ring 500 is movable in the front-to-rear direction inside the first casing 4A. The change ring 500 can move in the front-to-rear direction while being guided by the protrusions 500C provided in the guide grooves on the inner circumferential surface of the first casing 4A. The change ring 500 is disposed around at least one of the internal gears 311R and 312R.

[0214] The change ring 500 is connected to a first switching wire 510. The change ring 500 is movable in the front-to-rear direction inside the first casing 4A. When the change ring 500 moves forward, the first deceleration mode is selected, and when the change ring 500 moves backward, the second deceleration mode is selected.

[0215] In the embodiment, the reduction ratio of the rear stage (first stage) of the first planetary gear mechanism 31 consisting of the planetary gear 311P and the internal gear 311R is different from the reduction ratio of the front stage (second stage) of the first planetary gear mechanism 31 consisting of the planetary gear 312P and the internal gear 312R. The reduction ratio of the front stage consisting of the planetary gear 312P and the internal gear 312R is greater than the reduction ratio of the rear stage consisting of the planetary gear 311P and the internal gear 311R. When the pinion gear 31S rotates at a constant rotation speed, the rotation speed of the first carrier 31C in the first deceleration mode is slower than the rotation speed of the first carrier 31C in the second deceleration mode.

[0216] The first switching wire 510 is disposed outside the first casing 4A. The first switching wire 510 is movable in the front-rear direction outside the first casing 4A. The tip of the first switching wire 510 is inserted into a groove 500A provided in the change ring 500. A through hole 4H is provided in the first casing 4A. The tip of the first switching wire 510 is disposed inside the first casing 4A via the through hole 4H. The tip of the first switching wire 510 is inserted into the groove 500A inside the first casing 4A. An upper portion of the first switching wire 510 is fixed to a first movable member 610. The first movable member 610 is connected to the speed switch lever 12. The first movable member 610 is guided in the front-rear direction by a guide rod 600. The guide rod 600 is disposed to extend in the front-rear direction. The guide rod 600 is fixed to the casing 4. As shown in FIG. 29 , in this embodiment, the rear end of the guide rod 600 is fixed to the bracket plate 4C. The front end of the guide rod 600 is fixed to the second casing 4B. A first guide hole extending in the front-rear direction is formed in the first movable member 610. The guide rod 600 passes through the first guide hole of the first movable member 610. The first spring 630 is a compression spring. The rear end of the first spring 630 is supported by the bracket plate 4C. The front end of the first spring 630 is connected to the first movable member 610. The first spring 630 generates an elastic force such that the first movable member 610 moves forward (in one direction). The first spring 630 urges the change ring 500 forward via the first movable member 610 and the first switching wire 510.

[0217] A plurality of cam teeth 311F are provided on the outer peripheral surface of the internal gear 311R. A plurality of cam teeth 312F are provided on the outer peripheral surface of the internal gear 312R. The protrusion 500C is a contact member that comes into contact with either the cam teeth 311F of the internal gear 311R or the cam teeth 312F of the internal gear 312R. The protrusion 500C is guided by a guide groove provided on the inner peripheral surface of the first casing 4A and moves between a position facing the outer peripheral surface of the internal gear 311R and a position facing the outer peripheral surface of the internal gear 312R. Contact between the cam teeth 311F and the protrusion 500C prevents rotation of the internal gear 311R. Contact between the cam teeth 312F and the protrusion 500C prevents rotation of the internal gear 312R.

[0218] The change ring 500 is connected to the speed switch lever 12 via a first switching wire 510 and a first movable member 610. The speed switch lever 12 is operated so that the first movable member 610 moves in the front-to-rear direction. By operating the speed switch lever 12 so that it moves in the front-to-rear direction, the first movable member 610 and the first switching wire 510 move in the front-to-rear direction, and the change ring 500 moves in the front-to-rear direction.

[0219] When the first movable member 610, the first switch wire 510, and the change ring 500 move forward and the change ring 500 is positioned around the internal gear 312R with the protrusions 500C positioned to face the outer circumferential surface of the internal gear 312R, the cam teeth 312F come into contact with the protrusions 500C. This prevents the internal gear 312R from rotating. In other words, when the first movable member 610, the first switch wire 510, and the change ring 500 move forward and the rotation of the internal gear 312R is prevented, the first planetary gear mechanism 31 enters the first deceleration mode.

[0220] When the first movable member 610, the first switch wire 510, and the change ring 500 move rearward and the change ring 500 is positioned around the internal gear 311R with the protrusions 500C positioned to face the outer circumferential surface of the internal gear 311R, the cam teeth 311F come into contact with the protrusions 500C. This prevents the internal gear 311R from rotating. In other words, when the first movable member 610, the first switch wire 510, and the change ring 500 move rearward and the internal gear 311R is prevented from rotating, the first planetary gear mechanism 31 enters the second deceleration mode.

[0221] The first movable member 610 can switch between fixing the internal gears 311R and 312R to a rotational state and allowing the internal gears 311R and 312R to rotate relative to the casing 4 (gear case).

[0222] The second speed switching mechanism 72 switches between an enabled mode in which the speed reduction function of the second planetary gear mechanism 32 is enabled, and a disabled mode in which the speed reduction function of the second planetary gear mechanism 32 is disabled. Placing the second planetary gear mechanism 32 in the enabled mode includes preventing rotation of the internal gear 32R. Placing the second planetary gear mechanism 32 in the disabled mode includes allowing rotation of the internal gear 32R. By preventing rotation of the internal gear 32R, the second planetary gear mechanism 32 is in the enabled mode. By allowing rotation of the internal gear 32R, the second planetary gear mechanism 32 is in the disabled mode.

[0223] The second speed change mechanism 72 has a second change wire 520 connected to the internal gear 32R, cam teeth 33F provided on the internal gear 33R, a second movable member 620, and a second spring 640.

[0224] The second switching wire 520 is disposed outside the first casing 4A. The second switching wire 520 is movable in the front-rear direction outside the first casing 4A. The tip of the second switching wire 520 is inserted into a groove 32E formed in the internal gear 32R. A through hole 4J is formed in the first casing 4A. The tip of the second switching wire 520 is disposed inside the first casing 4A via the through hole 4J. The tip of the second switching wire 520 is inserted into the groove 32E inside the first casing 4A. An upper portion of the second switching wire 520 is fixed to a second movable member 620. The second movable member 620 is connected to the speed switch lever 12. The second movable member 620 is disposed forward of the first movable member 610. The second movable member 620 is guided in the front-rear direction by a guide rod 600. A second guide hole extending in the front-rear direction is formed in the second movable member 620. The guide rod 600 passes through the second guide hole of the second movable member 620. The second spring 640 is a compression spring. The front end of the second spring 640 is supported by the second casing 4B. The rear end of the second spring 640 is connected to the second movable member 620. The second spring 640 generates an elastic force such that the second movable member 620 moves rearward (in the other direction). The second spring 640 urges the internal gear 32R rearward via the second movable member 620 and the second switch wire 520.

[0225] A plurality of cam teeth 32F are provided on the outer peripheral surface of the internal gear 32R. The cam teeth 32F can mesh with the cam teeth 33F of the internal gear 33R. When the internal gear 32R is inserted inside the internal gear 33R, the rotation of the internal gear 32R is prevented by the cam teeth 33F of the internal gear 33R.

[0226] The internal gear 33R is disposed in front of the internal gear 32R. The internal gear 33R is fixed to the second casing 4B. Cam teeth 33G are provided on the outer peripheral surface of the internal gear 33R. The cam teeth 33G are inserted into recesses provided on the inner peripheral surface of the second casing 4B. By inserting the cam teeth 33G into the recesses provided on the inner peripheral surface of the second casing 4B, relative movement between the internal gear 33R and the second casing 4B is suppressed.

[0227] The speed switch lever 12 is operated so that the second movable member 620 moves in the front-to-rear direction. By operating the speed switch lever 12 so that it moves in the front-to-rear direction, the second movable member 620 and the second switching wire 520 move in the front-to-rear direction, and the internal gear 32R moves in the front-to-rear direction. By the internal gear 32R moving in the front-to-rear direction, the internal gear 32R switches between a state in which it is inserted into the internal gear 33R and a state in which it is removed from the internal gear 33R.

[0228] The second movable member 620, the second switching wire 520, and the internal gear 32R move forward, at least a portion of the internal gear 32R is inserted inside the internal gear 33R, and the cam teeth 33F of the internal gear 33R mesh with the cam teeth 32F of the internal gear 32R, thereby preventing rotation of the internal gear 32R. In other words, the second movable member 620, the second switching wire 520, and the internal gear 32R move forward, preventing rotation of the internal gear 32R, and the second planetary gear mechanism 32 enters the enabled mode.

[0229] The second movable member 620, the second switching wire 520, and the internal gear 32R move rearward, the internal gear 32R is removed from the inside of the internal gear 33R, and the cam teeth 33F of the internal gear 33R and the cam teeth 32F of the internal gear 32R are separated, allowing the internal gear 32R to rotate. In other words, the second movable member 620, the second switching wire 520, and the internal gear 32R move rearward, allowing the internal gear 32R to rotate, and the second planetary gear mechanism 32 enters the disabled mode.

[0230] The second movable member 620 can switch between fixing the internal gear 32R to a rotational state and allowing the internal gear 32R to rotate relative to the casing 4 (gear case).

[0231] When the second planetary gear mechanism 32 is in the active mode, the internal gear 32R meshes only with the planetary gear 32P. When the second planetary gear mechanism 32 is in the inactive mode, the internal gear 32R meshes with both the planetary gear 32P and the first carrier 31C.

[0232] As described above, in the embodiment, the speed modes of the reduction mechanism 30 include the low speed mode (first speed), the medium speed mode (second speed), and the high speed mode (third speed).

[0233] The movable range of the speed switch lever 12 is defined in the front-to-rear direction. When the speed switch lever 12 is operated to move to the front of the movable range, the speed mode of the reduction mechanism 30 is set to low speed mode (first speed). When the speed switch lever 12 is operated to move to the middle of the movable range, the speed mode of the reduction mechanism 30 is set to medium speed mode (second speed). When the speed switch lever 12 is operated to move to the rear of the movable range, the speed mode of the reduction mechanism 30 is set to high speed mode (third speed).

[0234] The low speed mode includes the first planetary gear mechanism 31 being set to the first deceleration mode and the second planetary gear mechanism 32 being set to the active mode. When the speed selector lever 12 is operated to move to the front of its movable range and the second movable member 620 moves forward, the first planetary gear mechanism 31 is set to the first deceleration mode and the second planetary gear mechanism 32 is set to the active mode.

[0235] The medium speed mode includes a state in which the first planetary gear mechanism 31 is set to the first deceleration mode and the second planetary gear mechanism 32 is set to the disabled mode. When the speed selector lever 12 is operated to move to the middle of its movable range, the first planetary gear mechanism 31 is set to the first deceleration mode and the second planetary gear mechanism 32 is set to the disabled mode.

[0236] The high-speed mode includes the first planetary gear mechanism 31 being set to the second deceleration mode and the second planetary gear mechanism 32 being set to the disabled mode. When the speed selector lever 12 is operated to move to the rear of its movable range and the first movable member 610 moves rearward, the first planetary gear mechanism 31 is set to the second deceleration mode and the second planetary gear mechanism 32 is set to the disabled mode.

[0237] Fig. 35 is a view from above of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the low-speed mode (first speed). Fig. 36 is a cross-sectional view of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the low-speed mode (first speed), which corresponds to the cross-sectional view taken along line CC in Fig. 37. Fig. 37 is a cross-sectional view of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the low-speed mode (first speed), which corresponds to the cross-sectional view taken along line PP in Fig. 35. Fig. 38 is a diagram showing the internal structure of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the low-speed mode (first speed).

[0238] Fig. 39 is a view from above of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the medium speed mode (second speed). Fig. 40 is a cross-sectional view of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the medium speed mode (second speed), which corresponds to the cross-sectional view taken along line CC in Fig. 41. Fig. 41 is a cross-sectional view of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the medium speed mode (second speed), which corresponds to the cross-sectional view taken along line PP in Fig. 39. Fig. 42 is a diagram showing the internal structure of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to the medium speed mode (second speed).

[0239] Figure 43 is a view from above of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to high-speed mode (third speed). Figure 44 is a cross-sectional view of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to high-speed mode (third speed), which corresponds to the cross-sectional view taken along line CC in Figure 45. Figure 45 is a cross-sectional view of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to high-speed mode (third speed), which corresponds to the cross-sectional view taken along line PP in Figure 43. Figure 46 is a diagram showing the internal structure of the driver drill 1 when the reduction gear mechanism 30 according to the embodiment is set to high-speed mode (third speed).

[0240] The speed switch lever 12 is operated by an operator so that the first movable member 610 moves in the front-to-rear direction. The first movable member 610 moves in the front-to-rear direction while being guided by the guide rod 600. The speed switch lever 12 is operated by an operator so that the second movable member 620 moves in the front-to-rear direction. The second movable member 620 moves in the front-to-rear direction while being guided by the guide rod 600. The first spring 630 generates an elastic force so that the first movable member 610 moves forward. The second spring 640 generates an elastic force so that the second movable member 620 moves backward.

[0241] As shown in Figures 35, 36, 37, and 38, when shifting the speed reduction mechanism 30 from the medium speed mode (second speed) to the low speed mode (first speed), the operator operates the speed switch lever 12 so that the speed switch lever 12 moves forward against the elastic force (biasing force) of the second spring 640. As the speed switch lever 12 moves forward, the second movable member 620 moves forward against the elastic force of the second spring 640. Leaf springs 530 are fixed to both the left and right sides of the speed switch lever 12. The protrusions 530T of the leaf spring 530 are inserted into recesses provided in part of the motor housing portion 21, so that the speed switch lever 12 is positioned at the first speed position. When the second movable member 620 moves forward within the movable range of the second movable member 620, the first deceleration mode is set in which the rotation of the internal gear 312R of the first planetary gear mechanism 31 is prevented and the rotation of the internal gear 311R is permitted, and the effective mode is set in which the rotation of the internal gear 32R of the second planetary gear mechanism 32 is prevented.

[0242] As shown in Figures 43, 44, 45, and 46, when shifting the speed reduction mechanism 30 from the medium speed mode (second speed) to the high speed mode (third speed), the operator operates the speed switch lever 12 so that the speed switch lever 12 moves rearward against the elastic force (biasing force) of the first spring 630. As the speed switch lever 12 moves rearward, the first movable member 610 moves rearward against the elastic force of the first spring 630. Leaf springs 530 are fixed to both the left and right sides of the speed switch lever 12. As the convex portions 530T of the leaf spring 530 are inserted into concave portions provided in part of the motor housing portion 21, the speed switch lever 12 is positioned at the third speed position. When the first movable member 610 moves to the rear of the movable range of the first movable member 610, the first planetary gear mechanism 31 is set to a second deceleration mode in which rotation of the internal gear 311R is prevented and rotation of the internal gear 312R is permitted, and the second planetary gear mechanism 32 is set to an ineffective mode in which rotation of the internal gear 32R is permitted.

[0243] As shown in Figures 39, 40, 41, and 42, when changing the speed reduction mechanism 30 from low-speed mode (first speed) to medium-speed mode (second speed), the operator operates the speed selector lever 12 so that it moves rearward. The speed selector lever 12 and the second movable member 620 can move smoothly rearward due to the elastic force of the second spring 640. When changing the speed reduction mechanism 30 from high-speed mode (third speed) to medium-speed mode (second speed), the operator operates the speed selector lever 12 so that it moves forward. The speed selector lever 12 and the first movable member 610 can move smoothly forward due to the elastic force of the first spring 630. When the first movable member 610 moves in front of the first movable member 610 and the second movable member 620 moves behind the second movable member 620, the first deceleration mode is set in which the rotation of the internal gear 312R of the first planetary gear mechanism 31 is prevented and the rotation of the internal gear 311R is permitted, and the disabled mode is set in which the rotation of the internal gear 32R of the second planetary gear mechanism 32 is permitted.

[0244] [Other embodiments] In the above-described embodiment, the battery pack 20 attached to the battery attachment section 5 is used as the power source for the driver drill 1. A commercial power source (AC power source) may also be used as the power source for the driver drill 1.

[0245] In the above-described embodiment, the electric work machine is a driver drill (percussion driver drill), which is a type of power tool. The power tool is not limited to a driver drill. Examples of the power tool include an impact driver, an angle drill, a screwdriver, a hammer, a hammer drill, a circular saw, and a reciprocating saw. [Explanation of symbols]

[0246] 1...Driver drill, 2...Housing, 2L...Left housing, 2R...Right housing, 2S...Screw, 3...Rear cover, 3S...Screw, 4...Casing, 4A...First casing, 4B...Second casing, 4C...Bracket plate, 4D...Stop plate, 4E...Screw, 4F...Screw, 4G...Guide groove, 4H...Through hole, 4J...Through hole, 4S...Screw, 5...Battery mounting section, 6...Motor, 7...Power transmission mechanism, 8...Output section, 9...Fan, 10...Trigger lever, 11...Forward / reverse rotation switch lever, 12...Speed ​​switch lever, 13...Mode switch ring, 14...Light, 15...Interface panel , 16...dial, 17...controller, 18...intake port, 19...exhaust port, 20...battery pack, 21...motor housing section, 22...grip section, 23...battery holding section, 24...operation device, 25...display device, 26...controller case, 27...panel opening, 28...dial opening, 30...reduction mechanism, 31...first planetary gear mechanism, 31A...pin, 31C...first carrier, 31S...pinion gear, 32...second planetary gear mechanism, 32A...pin, 32C...second carrier, 32D...recess, 32E...groove, 32F...cam tooth, 32P...planetary gear, 32R...internal gear, 32 S...sun gear, 33...third planetary gear mechanism, 33A...pin, 33C...third carrier, 33F...cam tooth, 33G...cam tooth, 33P...planetary gear, 33R...internal gear, 33S...sun gear, 34...speed switching member, 34A...ring portion, 34B...slider portion, 34C...lever portion, 34D...pin, 34E...convex portion, 34F...coil spring, 34G...coil spring, 35...annular member, 36...cam ring, 37...lever member, 38...guide rod, 39...coil spring, 40...vibration mechanism, 41...first cam, 42...second cam, 43...vibration switching ring, 4 3S... opposing portion, 43T... protrusion, 44... stop ring, 45... support ring, 46... steel ball, 47... washer, 48... cam ring, 50... spindle lock mechanism, 51... lock cam, 52... lock ring, 61... stator, 61A... stator core, 61B... front insulator, 61C... rear insulator, 61D... coil, 61E... sensor circuit board, 61F... short-circuit member, 62... rotor, 62A... rotor core, 62B... permanent magnet, 71... first speed change mechanism, 72... second speed change mechanism, 63... rotor shaft, 64... bearing, 65... bearing,81...spindle, 81F...flange portion, 81R...screw hole, 82...chuck, 83...bearing, 84...bearing, 87...coil spring, 120...speed switching lever, 121...coil spring, 122...coil spring, 123...coil spring, 124...rotation stop pin, 130...mode switching ring, 150...first moving mechanism, 160...second moving mechanism, 250...cam pin, 250A...groove, 300...reduction mechanism, 310...first planetary gear mechanism, 310A...pin, 310C...first carrier, 310P...planetary gear, 310R...in Internal gear, 311A...first pin, 311C...first stage carrier, 311P...planetary gear, 312P...planetary gear, 311R...internal gear, 311F...cam teeth, 312R...internal gear, 311S...large diameter portion, 312A...second pin, 312C...second stage carrier, 312F...cam teeth, 312S...small diameter portion, 320...second planetary gear mechanism, 320A...pin, 320C...second carrier, 320D...recess, 320F...cam teeth, 320P...planetary gear, 320R...internal gear, 320S...sun gear, 330...third Planetary gear mechanism, 330A... pin, 330C... third carrier, 330P... planetary gear, 330R... internal gear, 330F... cam teeth, 330S... sun gear, 340... speed switching member, 340A... ring portion, 340B... cam portion, 340D... pin, 350... speed switching member, 360... cam ring, 370... cam ring, 371... cam surface, 371A... cam surface, 371B... cam surface, 372... recess, 380... cam ring, 381... cam surface, 381A... cam surface, 381B... cam surface, 382... recess, 390... speed switching member, 390A... ring Plate portion, 390B...cam portion, 400...casing, 400A...first casing, 400B...second casing, 400C...bracket plate, 400D...stop plate, 400E...support plate, 500...change ring, 500A...groove, 500B...ring portion, 500C...convex portion, 510...first switching wire, 520...second switching wire, 530...leaf spring, 530T...convex portion, 600...guide rod, 610...first movable member, 620...second movable member, 630...first spring, 640...second spring, 700...power transmission mechanism, AX...rotating shaft.

Claims

1. A motor; a first planetary gear mechanism including: a first stage portion including a plurality of first planetary gears arranged around a sun gear rotated by the motor and a first internal gear arranged around the plurality of first planetary gears; and a second stage portion having a different reduction ratio from that of the first stage portion and including a plurality of second planetary gears arranged around the sun gear and a second internal gear arranged around the plurality of second planetary gears; a second planetary gear mechanism that is disposed forward of the first planetary gear mechanism and is actuated by a rotational force of the first planetary gear mechanism; a spindle that rotates by the rotational force of the motor transmitted via the second planetary gear mechanism; a first speed switching mechanism that switches between a first deceleration mode in which rotation of the second internal gear is prevented and rotation of the first internal gear is permitted, and a second deceleration mode in which rotation of the first internal gear is prevented and rotation of the second internal gear is permitted; a second speed switching mechanism that switches between an effective mode in which rotation of the internal gear of the second planetary gear mechanism is prevented and an ineffective mode in which rotation of the internal gear is permitted, Electric work equipment.

2. the sun gear includes a large diameter portion and a small diameter portion disposed forward of the large diameter portion, the plurality of first planetary gears are arranged around the large diameter portion, The plurality of second planetary gears are arranged around the small diameter portion. The electric operating machine according to claim 1 .

3. cam teeth are provided on an outer peripheral surface of the first internal gear, cam teeth are provided on the outer peripheral surface of the second internal gear, the first speed switching mechanism has a contact member that comes into contact with either the cam teeth of the first internal gear or the cam teeth of the second internal gear; The electric operating machine according to claim 1 .

4. the first internal gear and the second internal gear are each housed in a casing, the casing has a guide groove that guides the contact member, the contact member moves to a position facing the outer circumferential surface of the first internal gear and a position facing the outer circumferential surface of the second internal gear while being guided by the guide groove. The electric operating machine according to claim 3.

5. the first speed switching mechanism has an annular member connected to the contact member and disposed around at least one of the first internal gear and the second internal gear, The annular member moves in the front-rear direction, thereby moving the contact member. The electric operating machine according to claim 4.

6. a speed change lever connected to the annular member; The annular member moves when the speed change lever is operated to move in the forward and backward directions. The electric operating machine according to claim 5.

7. the second speed change mechanism includes a speed change member connected to the speed change lever and the internal gear of the second planetary gear mechanism, respectively, and a cam ring into which the internal gear is inserted to prevent rotation of the internal gear, When the speed change lever is operated to move in the forward and backward directions, the internal gear is switched between a state in which it is inserted into the cam ring and a state in which it is removed from the cam ring. The electric operating machine according to claim 6.

8. The motor includes a stator and a rotor including a rotor shaft and rotating relative to the stator; The sun gear is provided at a front end of the rotor shaft. The electric operating machine according to claim 1 .

9. a third planetary gear mechanism that is disposed forward of the second planetary gear mechanism and is actuated by a rotational force of the second planetary gear mechanism, the spindle is coupled to the third planetary gear mechanism; The electric operating machine according to claim 1 .

10. A motor; a first planetary gear mechanism including: a first stage portion including a plurality of first planetary gears arranged around a sun gear rotated by the motor and a first internal gear arranged around the plurality of first planetary gears; and a second stage portion having a different reduction ratio from that of the first stage portion and including a plurality of second planetary gears arranged around the sun gear and a second internal gear arranged around the plurality of second planetary gears; a second planetary gear mechanism that is disposed forward of the first planetary gear mechanism and is actuated by a rotational force of the first planetary gear mechanism; a spindle that rotates by the rotational force of the motor transmitted via the second planetary gear mechanism; a casing that houses the first planetary gear mechanism and the second planetary gear mechanism; a guide rod fixed to the casing; a first movable member guided by the guide rod; a second movable member guided by the guide rod, a first deceleration mode in which rotation of the second internal gear is prevented and rotation of the first internal gear is permitted, and a second deceleration mode in which rotation of the first internal gear is prevented and rotation of the second internal gear is permitted, by movement of the first movable member; a movement of the second movable member switches between an effective mode in which rotation of the internal gear of the second planetary gear mechanism is prevented and an ineffective mode in which rotation of the internal gear is permitted; Electric work equipment.

11. a speed change lever that is operated to move the first movable member in a front-rear direction and that is operated to move the second movable member in a front-rear direction; a first spring that generates an elastic force so that the first movable member moves forward; a second spring that generates an elastic force so that the second movable member moves rearward, The electric operating machine according to claim 10.

12. A motor; a first planetary gear transmission mechanism including a plurality of planetary gears arranged around a sun gear rotated by the motor and internal gears arranged around the plurality of planetary gears; a second planetary gear change mechanism disposed forward of the first planetary gear change mechanism and actuated by a rotational force of the first planetary gear change mechanism; a spindle that rotates by the rotational force of the motor transmitted via the second planetary gear transmission mechanism; a casing that accommodates the first planetary gear transmission mechanism and the second planetary gear transmission mechanism; a guide rod fixed to the casing; a first movable member guided by the guide rod; a second movable member guided by the guide rod, The first deceleration mode and the second deceleration mode are switched by the movement of the first movable member, Movement of the second movable member switches between an effective mode in which rotation of the internal gear of the second planetary gear change transmission mechanism is prevented and an ineffective mode in which rotation of the internal gear is permitted. Electric work equipment.

13. a speed change lever that is operated to move the first movable member in a front-rear direction and that is operated to move the second movable member in a front-rear direction; a first spring that generates an elastic force so that the first movable member moves in one direction; a second spring that generates an elastic force so that the second movable member moves in another direction; The electric operating machine according to claim 12.

14. a motor having a stator and a rotor rotatable relative to the stator; a housing including a motor housing portion that houses the motor, a grip portion that extends downward from the motor housing portion, and a battery holding portion that is disposed below the grip portion; a first sun gear disposed on a front side of the stator and rotated directly or indirectly by the rotor; a first planetary gear meshing with the first sun gear; and a first internal gear meshing with the first planetary gear. a second sun gear disposed in front of the first internal gear and rotated directly or indirectly by the first planetary gear; a second planetary gear meshing with the second sun gear; and a second internal gear meshing with the second planetary gear. a gear case disposed on a front side of the stator and accommodating the first sun gear, the first planetary gear, the first internal gear, the second sun gear, and the second planetary gear; a spindle disposed in front of the second internal gear and rotated directly or indirectly by the second planetary gear; a chuck secured to the front of the spindle; a first movable member that can switch between a rotation fixed state and a rotational state of the first internal gear relative to the gear case; a second movable member that can switch between a rotation fixed state and a rotational state of the second internal gear relative to the gear case; a first guide hole formed in the first movable member; a second guide hole formed in the second movable member; a guide rod that passes through the first guide hole and the second guide hole and is capable of guiding the first movable member and the second movable member in the front-rear direction, Electric driver drill.

Images