Electric work machine

Abstract

To provide an electric work machine configured so that constituents of the machine can be suppressed from being broken even when loads acting on a spindle increase.SOLUTION: An electric work machine comprises a motor, a planetary gear mechanism, at least a portion of which is arranged closer to a front side than the motor, which is actuated by rotation force of the motor, a spindle, at least a portion of which is arranged closer to a front side than the planetary gear mechanism, and a spindle lock mechanism that transmits rotation force in one direction from a carrier of the planetary gear mechanism to the spindle. The carrier has a hole into which a rear part of the spindle is inserted. An outer surface of the rear part of the spindle includes two flat surfaces. An inner surface of the hole of the carrier includes two flat surfaces contacting the two flat surfaces of the spindle respectively. The spindle lock mechanism has a lock cam, arranged around the spindle, at a side closer to the front side than a front surface of the carrier, which can rotate together with the spindle, a lock ring arranged around the lock cam, and a plurality of cylindrical members arranged between the lock cam and the lock ring.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to an electric work machine. [Background technology]

[0002] BACKGROUND ART In the technical field of electric power tools, an electric power tool having a spindle lock mechanism, such as that disclosed in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-168840 Summary of the Invention [Problem to be solved by the invention]

[0004] In electric work machines, the rotational force of a motor may be transmitted to a spindle via a planetary gear mechanism. For example, when tightening a screw, if the torque applied to the spindle increases, the load on the planetary gear mechanism or the spindle lock mechanism increases, which may result in at least a portion of the planetary gear mechanism or the spindle lock mechanism being damaged.

[0005] The technology disclosed in this specification aims to suppress damage to components of an electric working machine even when the load on the spindle increases. [Means for solving the problem]

[0006] This specification discloses an electric working machine. The electric working machine may include a motor, a planetary gear mechanism, a spindle, and a spindle lock mechanism. At least a portion of the planetary gear mechanism may be disposed forward of the motor. The planetary gear mechanism may be actuated by rotational force of the motor. At least a portion of the spindle may be disposed forward of the planetary gear mechanism. The spindle lock mechanism may transmit rotational force in one direction from a carrier of the planetary gear mechanism to the spindle. The carrier may have a hole into which a rear portion of the spindle is inserted.

[0007] The outer surface of the rear of the spindle may include two flat surfaces. The inner surface of the hole in the carrier may include two flat surfaces that respectively contact the two flat surfaces of the spindle. The spindle locking mechanism may include a locking cam that is disposed around the spindle forward of the front surface of the carrier and is rotatable together with the spindle. The spindle locking mechanism may include a locking ring that is disposed around the locking cam. The spindle locking mechanism may include a plurality of cylindrical members that are disposed between the locking cam and the locking ring.

[0008] The outer surface of the rear of the spindle may include a plurality of flat surfaces. The inner surface of the hole in the carrier may include a plurality of flat surfaces that contact the respective flat surfaces of the spindle. The spindle locking mechanism may include a locking cam that is disposed around the spindle forward of the front surface of the carrier and is rotatable together with the spindle. The spindle locking mechanism may include a locking ring that is disposed around the locking cam. The spindle locking mechanism may include two cylindrical members that are disposed between the locking cam and the locking ring. [Effects of the Invention]

[0009] According to the technology disclosed in this specification, damage to components of an electric working machine is suppressed even when the load on the spindle increases. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a front perspective view showing a driver drill according to an embodiment. [Figure 2] FIG. 2 is a rear perspective view showing the driver drill according to the embodiment. [Figure 3] FIG. 3 is a side view showing the driver drill according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a driver drill according to an embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a part of the driver drill according to the embodiment. [Figure 6] FIG. 6 is a front perspective view showing the spindle lock mechanism according to the embodiment. [Figure 7] FIG. 7 is an exploded perspective view from the front showing the spindle lock mechanism according to the embodiment. [Figure 8] FIG. 8 is a rear perspective view showing the spindle lock mechanism according to the embodiment. [Figure 9] FIG. 9 is an exploded perspective view from the rear showing the spindle lock mechanism according to the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing the spindle lock mechanism according to the embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing the spindle lock mechanism according to the embodiment. [Figure 12] FIG. 12 is a front perspective view showing the spindle according to the embodiment. [Figure 13] FIG. 13 is a front perspective view showing the third carrier according to the embodiment. [Figure 14] FIG. 14 is a front view showing a third carrier according to the embodiment. [Figure 15] FIG. 15 is a front perspective view showing the lock cam and pin according to the embodiment. [Figure 16] FIG. 16 is a rear perspective view showing the lock cam and pin according to the embodiment. [Figure 17] FIG. 17 is a front view for explaining the positional relationship between the third carrier, the lock cam, and the pin according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] In one or more embodiments, the electric working machine may include a motor, a planetary gear mechanism, a spindle, and a spindle lock mechanism. At least a portion of the planetary gear mechanism may be disposed forward of the motor. The planetary gear mechanism may be actuated by rotational force of the motor. At least a portion of the spindle may be disposed forward of the planetary gear mechanism. The spindle lock mechanism may transmit rotational force in one direction from a carrier of the planetary gear mechanism to the spindle. The carrier may have a hole into which a rear portion of the spindle is inserted.

[0012] The outer surface of the rear of the spindle may include two flat surfaces. The inner surface of the hole in the carrier may include two flat surfaces that respectively contact the two flat surfaces of the spindle. The spindle locking mechanism may include a locking cam that is disposed around the spindle forward of the front surface of the carrier and is rotatable together with the spindle. The spindle locking mechanism may include a locking ring that is disposed around the locking cam. The spindle locking mechanism may include a plurality of cylindrical members that are disposed between the locking cam and the locking ring.

[0013] In the above configuration, the inner surface of the carrier's hole includes two flat surfaces that contact the two flat surfaces of the spindle, respectively, so that the rotational force of the carrier is transmitted directly to the spindle. Furthermore, because the inner surface and flat surfaces of the carrier's hole contact the flat surfaces on the outer surface of the spindle, stress concentration in the carrier and the spindle is suppressed. Therefore, damage to the carrier and the spindle is suppressed. Furthermore, a spindle lock mechanism including a lock cam, a lock ring, and multiple cylindrical members transmits the rotational force from the carrier to the spindle and blocks the transmission of the rotational force from the spindle to the carrier.

[0014] The outer surface of the rear of the spindle may include a plurality of flat surfaces. The inner surface of the hole in the carrier may include a plurality of flat surfaces that contact the respective flat surfaces of the spindle. The spindle locking mechanism may include a locking cam that is disposed around the spindle forward of the front surface of the carrier and is rotatable together with the spindle. The spindle locking mechanism may include a locking ring that is disposed around the locking cam. The spindle locking mechanism may include two cylindrical members that are disposed between the locking cam and the locking ring.

[0015] In the above configuration, the inner surface of the carrier hole includes multiple flat surfaces that contact each of the multiple flat surfaces of the spindle, so the rotational force of the carrier is transmitted directly to the spindle. Furthermore, the inner surface and flat surfaces of the carrier hole contact the flat surfaces on the outer surface of the spindle, suppressing stress concentration in the carrier and the spindle. Therefore, damage to the carrier and the spindle is suppressed. Furthermore, a spindle lock mechanism including a lock cam, a lock ring, and two cylindrical members transmits rotational force from the carrier to the spindle and blocks transmission of rotational force from the spindle to the carrier.

[0016] In one or more embodiments, the outer surface of the locking cam may include a first flat surface and a second flat surface. The cylindrical member may include a first cylindrical member disposed between the first flat surface of the locking cam and the inner surface of the locking ring, and a second cylindrical member disposed between the second flat surface of the locking cam and the inner surface of the locking ring.

[0017] In the above configuration, when a rotational force is applied to the spindle and the spindle attempts to rotate, the lock cam attempts to rotate together with the spindle. A lock ring is disposed around the lock cam. The lock ring does not rotate. When the lock cam rotates, the first cylindrical member moves as if pushed radially outward by the first flat surface, and the second cylindrical member moves as if pushed radially outward by the second flat surface. The first cylindrical member is sandwiched between the first flat surface and the inner surface of the lock ring. The second cylindrical member is sandwiched between the second flat surface and the inner surface of the lock ring. Each of the first cylindrical member and the second cylindrical member functions as a wedge that prevents the lock cam from rotating. Since the rotation of the lock cam is prevented, the rotation of the spindle is suppressed. This blocks the transmission of rotational force from the spindle to the carrier.

[0018] In one or more embodiments, the dimensions of the first flat surface and the first cylindrical member may be equal, and the dimensions of the second flat surface and the second cylindrical member may be equal, in a direction parallel to the rotational axis of the spindle.

[0019] In the above configuration, the first cylindrical member is properly positioned between the first flat surface and the inner surface of the locking ring, and similarly, the second cylindrical member is properly positioned between the second flat surface and the inner surface of the locking ring.

[0020] In one or more embodiments, the inner surface of the carrier bore may include a first set of two flat surfaces and a second set of two flat surfaces. The spindle and carrier may rotate relative to each other to change between a first contact state in which the two flat surfaces of the spindle contact the two flat surfaces of the first set but not the two flat surfaces of the second set, and a second contact state in which the two flat surfaces of the spindle contact the two flat surfaces of the second set but not the two flat surfaces of the first set.

[0021] In the above configuration, when a rotational force is applied to the spindle, the lock cam rotates until the wedge effects of the first and second cylindrical members are exerted. If the spindle and carrier cannot rotate relative to each other, it would be difficult to rotate the lock cam until the wedge effects of the first and second cylindrical members are exerted. However, because the spindle and carrier can rotate relative to each other slightly, the lock cam can be rotated until the wedge effects of the first and second cylindrical members are exerted.

[0022] In one or more embodiments, the carrier may have a plurality of protrusions spaced apart around the rotation axis of the carrier and protruding forward from a front surface of the carrier. The locking cam may be located radially inward of the protrusions. The cylindrical member may be located between a pair of the protrusions.

[0023] In the above configuration, the lock cam is positioned radially inward of the multiple protrusions, so excessive torque does not act on the lock cam. This reduces stress concentration on the lock cam and prevents damage to the lock cam. The cylindrical member is positioned between the pair of protrusions. Therefore, when the carrier rotates based on the rotational force of the motor, the cylindrical member can rotate together with the carrier. In other words, the cylindrical member can revolve (revolve) around the rotation axis of the carrier as the carrier rotates. This transmits rotational force from the carrier to the spindle.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] [Driver Drill Overview] In this embodiment, the electric work machine is a driver drill, which is a type of screw driving work machine.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] The housing 2 has a motor accommodating portion 21, a grip portion 22, and a battery holding portion 23.

[0033] The motor accommodating portion 21 accommodates the motor 6. The motor accommodating portion 21 is cylindrical.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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 includes a rotor shaft 63 extending in the axial direction.

[0043] 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.

[0044] The power transmission mechanism 7 includes a speed reduction mechanism 30 and a vibration mechanism 40 .

[0045] 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, the second planetary gear mechanism 32, and the third planetary gear mechanism 33 are each operated by the rotational force of the motor 6.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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 .

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] [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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] A pinion gear 31S is provided at the front end of the rotor shaft 63. The pinion gear 31S includes a large diameter portion 311S and a small diameter portion 312S disposed in front 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.

[0069] The first planetary gear mechanism 31 includes a plurality of planetary gears 311P arranged around the large diameter portion 311S of the pinion gear 31S, a plurality of planetary gears 312P arranged around the small diameter portion 312S of the pinion gear 31S, a first carrier 31C supporting each of the planetary gears 311P and 312P, an internal gear 311R arranged around the planetary gears 311P, and an internal gear 312R arranged around the 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. The planetary gears 311P and 312P are rotatably supported by the pin 31A. First carrier 31C rotatably supports planetary gear 311P and planetary gear 312P via pin 31A. Gears are provided on the outer periphery of first carrier 31C.

[0070] 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.

[0071] 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.

[0072] The speed reduction mechanism 30 also has a first speed change member 34 connected to the speed change lever 12 and a second speed change member 35 connected to the speed change lever 12 .

[0073] The first speed change member 34 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. The first speed change member 34 is movable in the front-rear direction inside the first casing 4A. By moving the first speed change member 34 forward, the second planetary gear mechanism 32 is in the enabled mode, and by moving the first speed change member 34 backward, the second planetary gear mechanism 32 is in the disabled mode. When the speed change lever 12 is operated to move in the front-rear direction, the first speed change member 34 moves in the front-rear direction.

[0074] In this embodiment, the internal gear 32R is connected to the first speed change member 34. As the first speed change member 34 moves forward or backward, the internal gear 32R moves forward or backward together with the first speed change member 34. A cam ring 36 is disposed in front of the internal gear 32R. Cam teeth are provided on the inner peripheral surface of the cam ring 36. Cam teeth are provided on the outer peripheral surface of the internal gear 32R. As the first speed change member 34 moves forward so that at least a portion of the internal gear 32R is inserted inside the cam ring 36, the cam teeth of the internal gear 32R mesh with the cam teeth of the cam ring 36, preventing rotation of the internal gear 32R. When the first speed change member 34 moves rearward so that the internal gear 32R is removed from the inside of the cam ring 36, the cam teeth of the internal gear 32R and the cam teeth of the cam ring 36 separate, allowing the internal gear 32R to rotate.

[0075] 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.

[0076] The second speed change member 35 switches between a first deceleration mode in which rotation of the internal gear 312R of the first planetary gear mechanism 31 is prevented but 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 but rotation of the internal gear 312R is allowed. The second speed change member 35 is movable in the front-rear direction inside the first casing 4A. The first deceleration mode is selected when the second speed change member 35 moves forward, and the second deceleration mode is selected when the second speed change member 35 moves backward. The second speed change member 35 moves in the front-rear direction when the speed change lever 12 is operated to move in the front-rear direction.

[0077] A cam pin (not shown in FIG. 5) is hooked onto the second speed change member 35. The cam pin is guided by a guide groove provided in the first casing 4A and is able to move in the front-to-rear direction together with the second speed change member 35. The cam pin is prevented from moving in the circumferential direction by being disposed in the guide groove.

[0078] When the second speed change member 35 moves forward and is positioned around the internal gear 312R, the cam pin comes into contact with the cam teeth provided on the outer peripheral surface of the internal gear 312R. This prevents the internal gear 312R from rotating. In other words, when the second speed change member 35 moves forward and prevents the internal gear 312R from rotating, the first planetary gear mechanism 31 enters the first reduction mode.

[0079] When the second speed change member 35 moves rearward and is positioned around the internal gear 311R, the cam pin comes into contact with the cam teeth provided on the outer peripheral surface of the internal gear 311R. This prevents the internal gear 311R from rotating. In other words, when the second speed change member 35 moves rearward and prevents the internal gear 311R from rotating, the first planetary gear mechanism 31 enters the second reduction mode.

[0080] 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. 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. 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. 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.

[0081] 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.

[0082] 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.

[0083] The medium 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] The chuck 82 is capable of holding a tool bit. The chuck 82 is connected to the front part of the spindle 81. A threaded hole 81R is provided at the front end of the spindle 81. The chuck 82 and the spindle 81 are fixed together by a screw 88. With the head of the screw 88 in contact with the chuck 82, the threaded part of the screw 88 is inserted into the threaded hole 81R, thereby connecting the chuck 82 and the spindle 81. When the spindle 81 rotates, the chuck 82 rotates. The chuck 82 rotates while holding the tool bit.

[0088] 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.

[0089] 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. The elastic force of the coil spring 87 causes the stop ring 44 to come into contact with the rear surface of the bearing 83.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] [Spindle lock mechanism] Next, the spindle lock mechanism 50 will be described. FIG. 6 is a front perspective view of the spindle lock mechanism 50 according to the embodiment. FIG. 7 is an exploded front perspective view of the spindle lock mechanism 50 according to the embodiment. FIG. 8 is a rear perspective view of the spindle lock mechanism 50 according to the embodiment. FIG. 9 is an exploded rear perspective view of the spindle lock mechanism 50 according to the embodiment. FIG. 10 is a cross-sectional view of the spindle lock mechanism 50 according to the embodiment, corresponding to the cross-sectional view taken along line AA in FIG. 6. FIG. 11 is a cross-sectional view of the spindle lock mechanism 50 according to the embodiment, corresponding to the cross-sectional view taken along line BB in FIG. 6. FIG. 12 is a front perspective view of the spindle 81 according to the embodiment. FIG. 13 is a front perspective view of the third carrier 33C according to the embodiment. FIG. 14 is a front view of the third carrier 33C according to the embodiment.

[0100] The spindle lock mechanism 50 transmits rotational force from the third carrier 33C to the spindle 81 and blocks the transmission of rotational force from the spindle 81 to the third carrier 33C. The spindle lock mechanism 50 functions as a one-way clutch that transmits rotational force in only one direction, from the third carrier 33C to the spindle 81.

[0101] The spindle lock mechanism 50 is connected to each of the spindle 81 and the third carrier 33C. The spindle lock mechanism 50 has a lock cam 51 arranged around the spindle 81, a lock ring 52 arranged around the lock cam 51, and a plurality of pins 53 (cylindrical members) arranged between the lock cam 51 and the lock ring 52.

[0102] The spindle 81 is a rod-shaped member that is long in the front-rear direction. The spindle 81 has a flange portion 81F and a screw hole 81R. As described above, the flange portion 81F contacts the front end portion of the coil spring 87. The threaded portion of the screw 88 is inserted into the screw hole 81R.

[0103] The outer surface of the rear of the spindle 81 includes a flat surface 81A, a flat surface 81B, a curved surface 81C, and a curved surface 81D. Each of the flat surface 81A, the flat surface 81B, the curved surface 81C, and the curved surface 81D is parallel to the rotation axis AX. The flat surface 81A and the flat surface 81B are parallel to each other. Each of the flat surface 81A and the flat surface 81B is formed so as to cut out the rear of the spindle 81 from the rear end of the spindle 81 toward the front. The curved surface 81C is formed so as to connect the left end of the flat surface 81A to the left end of the flat surface 81B. The curved surface 81D is formed so as to connect the right end of the flat surface 81A to the right end of the flat surface 81B. In a cross section perpendicular to the rotation axis AX, the curved surface 81C has an arc shape that bulges away from the rotation axis AX. In a cross section perpendicular to the rotation axis AX, the curved surface 81D has an arc shape that bulges out so as to move away from the rotation axis AX.

[0104] The third carrier 33C is disposed forward of the internal gear 33R and the planetary gear 33P. The internal gear 33R is disposed around the multiple planetary gears 33P. The third carrier 33C supports the multiple planetary gears 33P. Multiple pins 33A are supported on the third carrier 33C. The pins 33A protrude rearward from the rear surface of the third carrier 33C. The pins 33A rotatably support the planetary gear 33P. The third carrier 33C rotatably supports the planetary gear 33P via the pins 33A.

[0105] The third carrier 33C has a plate portion 330, a protrusion portion 331, a protrusion portion 332, a protrusion portion 333, a protrusion portion 334, a land portion 335, and a land portion 336.

[0106] The plate portion 330 is substantially disk-shaped. The front surface of the plate portion 330 and the rear surface of the plate portion 330 are parallel to each other. A hole 337 is provided in the center of the plate portion 330. The hole 337 is formed so as to penetrate through the front surface of the plate portion 330 and the rear surface of the plate portion 330.

[0107] Protrusions 331, 332, 333, and 334 each protrude forward from the front surface of plate portion 330. The protrusion amounts of protrusions 331, 332, 333, and 334 are substantially equal. The protrusion amounts of protrusions 331, 332, 333, and 334 refer to the protrusion amounts from the front surface of plate portion 330. Protrusions 331, 332, 333, and 334 are arranged at intervals around hole 337 (around rotation axis AX of third carrier 33C). Protrusion 331 is provided at the upper left of hole 337. Protrusion 332 is provided at the upper right of hole 337. Protrusion 333 is provided at the lower left of hole 337. Protrusion 334 is provided at the lower right of hole 337. In a plane perpendicular to the rotation axis AX, each of the protrusions 331, 332, 333, and 334 is provided to follow the outer shape of the hole 337. In a plane perpendicular to the rotation axis AX, each of the protrusions 331, 332, 333, and 334 is substantially arc-shaped.

[0108] Each of the land portions 335 and 336 protrudes forward from the front surface of the plate portion 330. The protrusion amount of the land portion 335 and the protrusion amount of the land portion 336 are substantially equal. The protrusion amounts of the lands 335 and 336 refer to the protrusion amounts from the front surface of the plate portion 330. In the circumferential direction, the land portion 335 is provided between the protrusion portion 331 and the protrusion portion 332. In the circumferential direction, the land portion 336 is provided between the protrusion portion 333 and the protrusion portion 334. The protrusion amount of the land portion 335 is smaller than the protrusion amounts of the protrusion portion 331 and the protrusion portion 332. The protrusion amount of the land portion 336 is smaller than the protrusion amounts of the protrusion portion 333 and the protrusion portion 334. In a plane perpendicular to the rotation axis AX, each of the land portions 335 and 336 is provided to follow the outer shape of the hole 337. In a plane perpendicular to the rotation axis AX, each of the land portion 335 and the land portion 336 is substantially arc-shaped.

[0109] 13 and 14, third carrier 33C has flat surface 3371A, flat surface 3371B, flat surface 3372A, flat surface 3372B, curved surface 337C, and curved surface 337D. Flat surface 3371A, flat surface 3371B, flat surface 3372A, flat surface 3372B, curved surface 337C, and curved surface 337D are each parallel to rotation axis AX.

[0110] The flat surface 3371A includes a part of the inner surface of the hole 337 and a part of the inner surface of the land portion 335 facing the hole 337. The flat surface 3372A includes a part of the inner surface of the hole 337 and a part of the inner surface of the land portion 335 facing the hole 337.

[0111] The flat surface 3371B includes a part of the inner surface of the hole 337 and a part of the inner surface of the land portion 336 facing the hole 337. The flat surface 3372B includes a part of the inner surface of the hole 337 and a part of the inner surface of the land portion 336 facing the hole 337.

[0112] Flat surface 3371A and flat surface 3372A are adjacent to each other. Flat surface 3371A is disposed to the left of flat surface 3372A. The angle formed between flat surface 3371A and flat surface 3372A is greater than 180°. Flat surface 3371B and flat surface 3372B are adjacent to each other. Flat surface 3371B is disposed to the right of flat surface 3372B. The angle formed between flat surface 3371B and flat surface 3372B is greater than 180°. Flat surface 3371A and flat surface 3371B are parallel. Flat surface 3372A and flat surface 3372B are parallel.

[0113] Curved surface 337C includes a portion of the inner surface of hole 337. On the inner surface of hole 337, curved surface 337C is formed so as to connect the left end of flat surface 3371A to the left end of flat surface 3372B. Curved surface 337D includes a portion of the inner surface of hole 337. On the inner surface of hole 337, curved surface 337D is formed so as to connect the right end of flat surface 3372A to the right end of flat surface 3371B. In a cross section perpendicular to rotation axis AX, curved surface 337C has an arc shape that bulges away from rotation axis AX. In a cross section perpendicular to rotation axis AX, curved surface 337D has an arc shape that bulges away from rotation axis AX.

[0114] Furthermore, land portion 335 has support surfaces 335A connected to the front surface of plate portion 330 and the inner surface of protrusion 331 facing radially inward, and support surfaces 335B connected to the front surface of plate portion 330 and the inner surface of protrusion 332 facing radially inward. Land portion 336 has support surfaces 336A connected to the front surface of plate portion 330 and the inner surface of protrusion 333 facing radially inward, and support surfaces 336B connected to the front surface of plate portion 330 and the inner surface of protrusion 334 facing radially inward. Each of support surfaces 335A, 335B, 336A, and 336B is parallel to rotation axis AX.

[0115] Fig. 15 is a front perspective view showing the lock cam 51 and the pin 53 according to the embodiment. Fig. 16 is a rear perspective view showing the lock cam 51 and the pin 53 according to the embodiment.

[0116] The lock cam 51 is disposed around the spindle 81, forward of the front surface of the plate portion 330 of the third carrier 33C. The lock cam 51 has a cylindrical portion 511, a protrusion 512, and another protrusion 513.

[0117] The outer surface of the lock cam 51 includes a flat surface 511A, a flat surface 511B, a curved surface 511C, and a curved surface 511D. Each of the flat surface 511A, the flat surface 511B, the curved surface 511C, and the curved surface 511D is parallel to the rotation axis AX. The flat surface 511A and the flat surface 511B are parallel to each other. The curved surface 511C is formed so as to connect the upper end of the flat surface 511A to the upper end of the flat surface 511B. The curved surface 511D is formed so as to connect the lower end of the flat surface 511A to the lower end of the flat surface 511B. In a cross section perpendicular to the rotation axis AX, the curved surface 511C has an arc shape that bulges away from the rotation axis AX. In a cross section perpendicular to the rotation axis AX, the curved surface 511D has an arc shape that bulges away from the rotation axis AX.

[0118] The cylindrical portion 511 is disposed around the rear portion of the spindle 81. The outer surface of the cylindrical portion 511 includes a portion of a flat surface 511A, a portion of a flat surface 511B, a curved surface 511C, and a curved surface 511D. A portion of the flat surface 511A is provided on the left portion of the cylindrical portion 511. A portion of the flat surface 511B is provided on the right portion of the cylindrical portion 511.

[0119] A hole 514 is provided in the center of the cylindrical portion 511. The hole 514 is formed so as to penetrate from the front surface of the cylindrical portion 511 to the rear surface of the cylindrical portion 511. The rear portion of the spindle 81 is disposed in the hole 514.

[0120] The inner surface of hole 514 includes flat surface 514A, flat surface 514B, curved surface 514C, and curved surface 514D. Flat surface 514A, flat surface 514B, curved surface 514C, and curved surface 514D are each parallel to rotation axis AX. Flat surface 514A and flat surface 514B are parallel. Curved surface 514C is formed to connect the left end of flat surface 514A to the left end of flat surface 514B. Curved surface 514D is formed to connect the right end of flat surface 514A to the right end of flat surface 514B. In a cross section perpendicular to rotation axis AX, curved surface 514C has an arc shape that bulges away from rotation axis AX. In a cross section perpendicular to rotation axis AX, curved surface 514D has an arc shape that bulges away from rotation axis AX.

[0121] Protrusion 512 and protrusion 513 each protrude rearward from the rear surface of tubular portion 511. A portion of flat surface 511A is provided on the side surface of protrusion 512. A portion of flat surface 511B is provided on the side surface of protrusion 513. The protrusion amount of protrusion 512 and the protrusion amount of protrusion 513 are substantially equal. The protrusion amounts of protrusions 512 and 513 refer to the protrusion amounts from the rear surface of tubular portion 511. Protrusion 512 is provided to the left of hole 514. Protrusion 513 is provided to the right of hole 514. Protrusion 512 and protrusion 513 are each formed so as not to protrude radially outward from the outer surface of tubular portion 511.

[0122] The lock ring 52 rotatably supports the lock cam 51. The lock ring 52 is disposed around the lock cam 51. The lock ring 52 is fixed to the second casing 4B. The lock ring 52 does not rotate.

[0123] A plurality of pins 53 are arranged around the lock cam 51. In this embodiment, two pins 53 are arranged around the lock cam 51. One pin 53 is arranged to face the flat surface 511A of the lock cam 51. The other pin 53 is arranged to face the flat surface 511B of the lock cam 51. In the front-to-rear direction, the dimensions of the flat surface 511A and the pin 53 are substantially equal. In the front-to-rear direction, the dimensions of the flat surface 511B and the pin 53 are substantially equal.

[0124] FIG. 17 is a front view for explaining the positional relationship between the third carrier 33C, the lock cam 51, and the pin 53 according to the embodiment.

[0125] 11 and 17, the lock cam 51 is disposed radially inward of the multiple protrusions 331, 332, 333, and 334. As shown in Fig. 11, at least a portion of the lock ring 52 is disposed radially outward of the multiple protrusions 331, 332, 333, and 334.

[0126] The pin 53 is disposed between the outer surface of the lock cam 51 and the inner surface of the lock ring 52. The pin 53 is disposed between the lock cam 51 and the lock ring 52 so that the central axis of the pin 53 and the rotation axis AX of the spindle 81 are parallel to each other.

[0127] The pin 53 facing the flat surface 511A is disposed circumferentially between the lower end surface 331T of the protrusion 331 and the upper end surface 333T of the protrusion 333. The pin 53 facing the flat surface 511B is disposed circumferentially between the lower end surface 332T of the protrusion 332 and the upper end surface 334T of the protrusion 334.

[0128] The cylindrical portion 511 of the lock cam 51 is disposed radially inward of the protrusions 331, 332, 333, 334, the land portions 335, and 336. The rear surface of the cylindrical portion 511 faces the front surface of the land portion 335 and the front surface of the land portion 336, respectively.

[0129] Protrusion 512 is disposed between support surface 335A of land portion 335 and support surface 336A of land portion 336. The rear surface of protrusion 512 faces the front surface of tube portion 511 to the left of hole 337. Protrusion 513 is disposed between support surface 335B of land portion 335 and support surface 336B of land portion 336. The rear surface of protrusion 513 faces the front surface of tube portion 511 to the right of hole 337.

[0130] 11, one pin 53 is disposed between a flat surface 511A of the lock cam 51 and the inner surface of the lock ring 52. Another pin 53 is disposed between a flat surface 511B of the lock cam 51 and the inner surface of the lock ring 52.

[0131] The rear portion of the spindle 81 is inserted into the hole 337 of the third carrier 33C. The flat surface 81A of the spindle 81 contacts either the flat surface 3371A or the flat surface 3372A. The flat surface 81B of the spindle 81 contacts either the flat surface 3371B or the flat surface 3372B. The curved surface 81C of the spindle 81 faces the curved surface 337C. The curved surface 81D of the spindle 81 faces the curved surface 337D.

[0132] When flat surface 81A of spindle 81 comes into contact with flat surface 3371A, flat surface 81B of spindle 81 comes into contact with flat surface 3371B. When flat surface 81A comes into contact with flat surface 3371A and flat surface 81B comes into contact with flat surface 3371B, flat surface 81A comes into contact with flat surface 3372A, and flat surface 81B comes into contact with flat surface 3372B.

[0133] When flat surface 81A of spindle 81 comes into contact with flat surface 3372A, flat surface 81B of spindle 81 comes into contact with flat surface 3372B. When flat surface 81A comes into contact with flat surface 3372A and flat surface 81B comes into contact with flat surface 3372B, flat surface 81A and flat surface 3371A separate, and flat surface 81B and flat surface 3371B separate.

[0134] In the following description, the state in which flat surface 81A and flat surface 3371A are in contact and flat surface 81B of spindle 81 is in contact with flat surface 3371B will be referred to as the first contact state, and the state in which flat surface 81A and flat surface 3372A are in contact and flat surface 81B and flat surface 3372B are in contact will be referred to as the second contact state.

[0135] In this embodiment, the spindle 81 and the third carrier 33C can rotate slightly relative to each other so as to change between the first contact state and the second contact state.

[0136] In addition, the rear portion of the spindle 81 is inserted into the hole 514 of the lock cam 51. The flat surface 81A of the spindle 81 faces the flat surface 514A. The flat surface 81B of the spindle 81 faces the flat surface 514B. The curved surface 81C of the spindle 81 faces the curved surface 514C. The curved surface 81D of the spindle 81 faces the curved surface 514D. The lock cam 51 is rotatable together with the spindle 81.

[0137] When the motor 6 is driven to rotate the third carrier 33C in the direction of the arrow Ra shown in FIGS. 11, 14, and 17, the flat surface 81A contacts the flat surface 3371A, and the flat surface 81B of the spindle 81 contacts the flat surface 3371B, forming a first contact state. The spindle 81 rotates together with the third carrier 33C in the direction of the arrow Ra. Furthermore, when the spindle 81 rotates, the lock cam 51 rotates together with the spindle 81 in the direction of the arrow Ra. Furthermore, as the third carrier 33C rotates in the direction of the arrow Ra, the pin 53 facing the flat surface 511A rotates together with the third carrier 33C while contacting the lower end surface 331T of the protrusion 331. The pin 53 facing the flat surface 511B rotates together with the third carrier 33C while contacting the upper end surface 334T of the protrusion 334.

[0138] When the motor 6 is driven to rotate the third carrier 33C in the direction of arrow Rb shown in FIGS. 11, 14, and 17, the flat surface 81A contacts the flat surface 3372A, and the flat surface 81B of the spindle 81 contacts the flat surface 3372B, forming a second contact state. The spindle 81 rotates together with the third carrier 33C in the direction of arrow Rb. Furthermore, when the spindle 81 rotates, the lock cam 51 rotates together with the spindle 81 in the direction of arrow Rb. Furthermore, as the third carrier 33C rotates in the direction of arrow Rb, the pin 53 facing the flat surface 511A rotates together with the third carrier 33C while contacting the upper end surface 333T of the protrusion 333. The pin 53 facing the flat surface 511B rotates together with the third carrier 33C while contacting the lower end surface 332T of the protrusion 332.

[0139] In this way, when the third carrier 33C is rotated by the drive of the motor 6, the rotational force of the third carrier 33C is transmitted to the spindle 81. The third carrier 33C and the spindle 81 rotate together while maintaining the relative positions of the lock cam 51 and the pin 53 in the circumferential direction.

[0140] For example, when attaching a tool bit to the output unit 8, an operator may apply a rotational force to the spindle 81. For example, the spindle 81 may rotate when the chuck 82 is tightened. To smoothly attach the tool bit to the output unit 8, it is preferable to suppress the rotation of the spindle 81. When attaching the tool bit, the spindle lock mechanism 50 blocks the transmission of rotational force from the spindle 81 to the third carrier 33C. In other words, the rotation of the spindle 81 is suppressed. This allows the tool bit to be smoothly attached to the output unit 8.

[0141] When a rotational force is applied to the spindle 81 and the spindle 81 attempts to rotate, the lock cam 51 also attempts to rotate together with the spindle 81. A lock ring 52 is disposed around the lock cam 51. The lock ring 52 is fixed to the casing 4 and does not rotate. When the lock cam 51 rotates, the pin 53 facing the flat surface 511A moves as if being pushed radially outward by the flat surface 511A, and the pin 53 facing the flat surface 511B moves as if being pushed radially outward by the flat surface 511B. One pin 53 is sandwiched between the flat surface 511A and the inner surface of the lock ring 52. The other pin 53 is sandwiched between the flat surface 511B and the inner surface of the lock ring 52. The pin 53 functions as a wedge that prevents the lock cam 51 from rotating. The wedge effect of the pin 53 prevents the lock cam 51 from rotating, thereby suppressing the rotation of the spindle 81. The transmission of rotational force from the spindle 81 to the third carrier 33C is cut off.

[0142] As described above, the spindle 81 and the third carrier 33C can rotate slightly relative to each other to change between the first contact state and the second contact state. If the spindle 81 and the third carrier 33C could not rotate relative to each other, it would be difficult to rotate the lock cam 51 until the wedge effect of the pin 53 is exerted. In this embodiment, because the spindle 81 and the third carrier 33C can rotate slightly relative to each other, the lock cam 51 can be rotated until the wedge effect of the pin 53 is exerted.

[0143] [effect] As described above, in the embodiment, the driver drill 1 includes the motor 6, the third planetary gear mechanism 33, the spindle 81, and the spindle lock mechanism 50. At least a portion of the third planetary gear mechanism 33 is disposed forward of the motor 6. The third planetary gear mechanism 33 is actuated by the rotational force of the motor 6. At least a portion of the spindle 81 is disposed forward of the third planetary gear mechanism 33. The spindle lock mechanism 50 transmits the rotational force in one direction from the third carrier 33C of the third planetary gear mechanism 33 to the spindle 81. The third carrier 33C has a hole 337 into which the rear portion of the spindle 81 is inserted.

[0144] The outer surface of the rear of the spindle 81 includes two flat surfaces 81A and 81B. The inner surface of the hole 337 of the third carrier 33C includes two flat surfaces 3371A and 3371B (3372A and 3372B) that come into contact with the two flat surfaces 81A and 81B of the spindle 81, respectively. The spindle lock mechanism 50 is disposed around the spindle 81 forward of the front surface of the plate portion 330 of the third carrier 33C and has a lock cam 51 that is rotatable together with the spindle 81. The spindle lock mechanism 50 has a lock ring 52 that is disposed around the lock cam 51. The spindle lock mechanism 50 has two pins 53 (cylindrical members) that are disposed between the lock cam 51 and the lock ring 52.

[0145] In the above configuration, the inner surface of hole 337 of third carrier 33C includes two flat surfaces 3371A, 3371B (3372A, 3372B) that contact two flat surfaces 81A, 81B of the spindle, respectively, so that the rotational force of third carrier 33C is transmitted directly to spindle 81. Furthermore, the inner surface of hole 337 of third carrier 33C and flat surfaces 3371A, 3371B (3372A, 3372B) come into contact with flat surfaces 81A, 81B on the outer surface of spindle 81, so that stress concentration in each of third carrier 33C and spindle 81 is suppressed. Therefore, damage to third carrier 33C and spindle 81 is suppressed. In addition, a spindle lock mechanism 50 having a lock cam 51, a lock ring 52, and two pins 53 transmits rotational force from the third carrier 33C to the spindle 81 and blocks the transmission of rotational force from the spindle 81 to the third carrier 33C.

[0146] In the embodiment, the outer surface of the lock cam 51 includes a first flat surface 511A and a second flat surface 511B. The pins 53 include a first pin 53 disposed between the flat surface 511A of the lock cam 51 and the inner surface of the lock ring 52, and a second pin 53 disposed between the flat surface 511B of the lock cam 51 and the inner surface of the lock ring 52.

[0147] In the above configuration, when a rotational force is applied to the spindle 81 and the spindle 81 attempts to rotate, the lock cam 51 also attempts to rotate together with the spindle 81. A lock ring 52 is disposed around the lock cam 51. The lock ring 52 does not rotate. When the lock cam 51 rotates, the first pin 53 moves so as to be pushed radially outward by the flat surface 511A, and the second pin 53 moves so as to be pushed radially outward by the flat surface 511B. The first pin 53 is sandwiched between the flat surface 511A and the inner surface of the lock ring 52. The second pin 53 is sandwiched between the flat surface 511B and the inner surface of the lock ring 52. Each of the first pin 53 and the second pin 53 functions as a wedge that prevents the lock cam 51 from rotating. Since the rotation of the lock cam 51 is prevented, the rotation of the spindle 81 is suppressed. This blocks the transmission of rotational force from the spindle 81 to the third carrier 33C.

[0148] In the embodiment, in the front-rear direction parallel to the rotation axis AX of the spindle 81, the dimensions of the flat surface 511A and the first pin 53 are substantially equal, and the dimensions of the flat surface 511B and the second pin 53 are substantially equal.

[0149] In the above configuration, the first pin 53 is properly positioned between the flat surface 511A and the inner surface of the lock ring 52. Similarly, the second pin 53 is properly positioned between the flat surface 511B and the inner surface of the lock ring 52.

[0150] In the embodiment, the inner surface of the hole 337 of the third carrier 33C includes a first set of two flat surfaces 3371A, 3371B and a second set of two flat surfaces 3372A, 3372B. The spindle 81 and the third carrier 33C rotate relative to each other to change between a first contact state in which the two flat surfaces 81A, 81B of the spindle 81 contact the two flat surfaces 3371A, 3371B of the first set but not the two flat surfaces 3372A, 3372B of the second set, and a second contact state in which the two flat surfaces 81A, 81B of the spindle 81 contact the two flat surfaces 3372A, 3372B of the second set but not the two flat surfaces 3371A, 3371B of the first set.

[0151] In the above configuration, when a rotational force is applied to the spindle 81, the lock cam 51 rotates until the wedge effects of the first pin 53 and the second pin 53 are exerted. If the spindle 81 and the third carrier 33C cannot rotate relative to each other, it would be difficult to rotate the lock cam 51 until the wedge effects of the first pin 53 and the second pin 53 are exerted. However, because the spindle 81 and the third carrier 33C can rotate slightly relative to each other, the lock cam 51 can be rotated until the wedge effects of the first pin 53 and the second pin 53 are exerted.

[0152] In the embodiment, the third carrier 33C has a plurality of protrusions 331, 332, 333, and 334 that are spaced apart around the rotation axis AX of the third carrier 33C and protrude forward from the front surface of the third carrier 33C. The lock cam 51 is disposed radially inward of the protrusions 331, 332, 333, and 334. The first pin 53 is disposed between the protrusions 331 and 333. The second pin 53 is disposed between the protrusions 332 and 334.

[0153] In the above configuration, the lock cam 51 is positioned radially inward of the multiple protrusions 331, 332, 333, and 334, so that excessive torque does not act on the lock cam 51. This reduces stress concentration on the lock cam 51 and prevents damage to the lock cam 51. The first pin 53 is positioned between the pair of protrusions 331 and 333, and the second pin 53 is positioned between the pair of protrusions 332 and 334. Therefore, when the third carrier 33C rotates based on the rotational force of the motor 6, the pin 53 can rotate together with the third carrier 33C. In other words, the pin 53 can revolve (revolve) around the rotation axis AX in accordance with the rotation of the third carrier 33C. This allows the rotational force to be transmitted from the third carrier 33C to the spindle 81.

[0154] [Other embodiments] In the above-described embodiment, the outer surface of the rear of the spindle 81 includes two flat surfaces 81A, 81B, and the inner surface of the hole 337 of the third carrier 33C includes two flat surfaces 3371A, 3371B (3372A, 3372B) that contact the two flat surfaces 81A, 81B of the spindle 81, respectively. The outer surface of the rear of the spindle 81 may include any number of three or more flat surfaces, and the inner surface of the hole 337 of the third carrier 33C may include any number of three or more flat surfaces that contact the plurality of flat surfaces of the spindle 81, respectively.

[0155] In the above-described embodiment, the spindle lock mechanism 50 has two pins 53 (cylindrical members) arranged between the lock cam 51 and the lock ring 52. The spindle lock mechanism 50 may have any number of pins 53 (cylindrical members), three or more, arranged between the lock cam 51 and the lock ring 52.

[0156] 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.

[0157] 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]

[0158] 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, 4S...Screw, 5...Battery mounting section, 6...Motor, 7...Power transmission mechanism, 8...Output section, 9...Fan, 10...Trigger lever, 11...Forward / reverse 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, 32P...planetary gear, 32R...internal gear, 32S...sun gear, 33...third planetary gear mechanism, 33A...pin, 33C...third carrier, 33P... Planetary gear, 33R...internal gear, 33S...sun gear, 34...first speed change member, 35...second speed change member, 36...cam ring, 40...vibration mechanism, 41...first cam, 42...second cam, 43...vibration change ring, 43S...opposing portion, 43T...projection portion, 44...stop ring, 45...support ring, 46...steel ball, 47...washer, 48...cam ring, 50...spindle lock mechanism, 51...lock cam, 52...lock ring, 53...pin (cylindrical member), 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, 63...rotor shaft, 64...bearing, 65...bearing, 81...spindle, 81A...flat surface, 81B...flat surface, 81C...curved surface, 81D...curved surface, 81F...flange portion, 81R...screw hole, 82...chuck, 83...bearing, 84...bearing, 87...coil spring, 88...screw, 311P...planetary gear, 312P...planetary gear, 311R...internal gear, 312R...internal gear, 311S...large diameter portion,312S...small diameter part, 330...プレート part, 331...projection part, 331T...lower end surface, 332...projection part, 332T...lower end surface, 333...projection part, 333T...upper end surface, 334...projection part, 334T...upper end surface, 335...ランド part, 335A...supporting surface, 335B...supporting surface, 336...ランド part, 336A...supporting surface, 336B...supporting surface, 337...hole, 3372A... Flat surface, 3372B...flat surface, 337C...curved surface, 337D...curved surface, 511...cylinder, 511A...flat surface, 511B...flat surface, 511C...curved surface, 511D...curved surface, 512...protrusion, 513...protrusion, 514...hole, 514A...flat surface, 514B...flat surface, 514C...curved surface, 514D...curved surface, 3371A...flat surface, 3371B...flat surface, AX...rotation axis.

Claims

1. A motor having a stator and a rotor that rotates around a rotation axis extending in the front-to-rear direction; a planetary gear mechanism, at least a portion of which is disposed forward of the motor, which has a carrier and is actuated by the rotational force of the rotor; a spindle at least a portion of which is disposed forward of the planetary gear mechanism; a spindle lock mechanism that transmits a rotational force of the carrier to the spindle when the carrier is rotated by driving the motor and blocks transmission of the rotational force from the spindle to the carrier, the carrier has a bore having an interior surface including two carrier flats; the spindle is inserted into the bore and has a rear portion with an outer surface including two spindle flats; The two spindle flat surfaces are parallel to the rotation axis; The two spindle flat surfaces are configured to contact the corresponding carrier flat surfaces, the spindle lock mechanism includes a lock cam that is disposed around the spindle forward of the front surface of the carrier and is rotatable together with the spindle, a lock ring that is disposed around the lock cam, and a plurality of cylindrical members that are disposed between the lock cam and the lock ring, the locking cam has an outer surface including a first flat surface and a second flat surface; the first flat surface and the second flat surface face outward in a radial direction; The cylindrical member includes a first cylindrical member disposed between a first flat surface of the lock cam and an inner surface of the lock ring, and a second cylindrical member disposed between a second flat surface of the lock cam and the inner surface of the lock ring. Electric work equipment.

2. The lock cam has a cylindrical portion into which the rear portion of the spindle is inserted, and two cam protrusions protruding rearward from the rear surface of the cylindrical portion, the first flat surface is provided on a side surface of one of the cam protrusions, The second flat surface is provided on a side surface of the other cam protrusion. The electric operating machine according to claim 1 .

3. In a direction parallel to the rotation axis of the spindle, a dimension of the first flat surface and a dimension of the first cylindrical member are equal, and a dimension of the second flat surface and a dimension of the second cylindrical member are equal. The electric operating machine according to claim 1 .

4. the inner surface of the carrier hole includes a first set of two carrier flat surfaces and a second set of two carrier flat surfaces; The spindle and the carrier rotate relative to each other so as to change between a first contact state in which the two spindle flat surfaces of the spindle contact the two carrier flat surfaces of the first set but do not contact the two carrier flat surfaces of the second set, and a second contact state in which the two spindle flat surfaces of the spindle contact the two carrier flat surfaces of the second set but do not contact the two carrier flat surfaces of the first set. The electric operating machine according to claim 1 .

5. the carrier has a plurality of carrier protrusions spaced apart around the rotation axis of the carrier and protruding forward from a front surface of the carrier; the lock cam is disposed radially inward of the carrier protrusion, The cylindrical member is disposed between the pair of carrier protrusions. The electric operating machine according to any one of claims 1 to 4.

6. The inner surface of the carrier hole includes a first set of two carrier flat surfaces that are parallel to the rotation axis, adjacent to each other, and form an angle between them that is greater than 180 degrees, and a second set of two carrier flat surfaces that are parallel to the rotation axis, adjacent to each other, and form an angle between them that is greater than 180 degrees, the spindle and the carrier rotate relative to each other so as to change between a first contact state in which the two spindle flat surfaces are in contact with the two carrier flat surfaces of the first set but not in contact with the two carrier flat surfaces of the second set, and a second contact state in which the two spindle flat surfaces are in contact with the two carrier flat surfaces of the second set but not in contact with the two carrier flat surfaces of the first set; the carrier has four carrier protrusions arranged at intervals around the rotation axis of the carrier and protruding forward from a front surface of the carrier, and two land portions protruding forward from the front surface of the carrier by smaller protrusion amounts than the carrier protrusions, one of the land portions is disposed between a first carrier protrusion portion and a second carrier protrusion portion; the other land portion is disposed between the third carrier protrusion portion and the fourth carrier protrusion portion; the lock cam has two cam protrusions protruding rearward from a rear surface of the lock cam and is disposed radially inward of the carrier protrusions, the cam protrusion is disposed between the two land portions and radially inward of the carrier protrusion, The outer surface of the locking cam includes a first flat surface at least a portion of which is provided on a side surface of one of the cam protrusions, and a second flat surface at least a portion of which is provided on a side surface of the other cam protrusion, The cylindrical members include a first cylindrical member disposed between the first flat surface of the lock cam and the inner surface of the lock ring between the first carrier protrusion and the third carrier protrusion, which are not provided with the land portion, and a second cylindrical member disposed between the second flat surface of the lock cam and the inner surface of the lock ring between the second carrier protrusion and the fourth carrier protrusion, which are not provided with the land portion. The electric operating machine according to claim 1 .

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