Power tool

Abstract

The present application provides an electric power tool having a reduction unit that is compact in the axial direction and has high durability even if a speed change mechanism is provided. The impact driver has a motor, a reduction unit (75) that reduces the rotation generated by the motor, and a striking unit (76) and a vibrating unit (77) that operate by the rotation reduced by the reduction unit (75). In addition, the reduction unit (75) has, in the axial direction, a three-stage internal gear (81A to 81C), a plurality of planetary gears (80A to 80C) that revolve in the internal gear (81A to 81C), and a rear gear carrier (85) and a front gear carrier (130) that respectively support each planetary gear (80A to 80C) by a pin (86, 131). Furthermore, each planetary gear (80A) of the front stage and each planetary gear (80B) of the rear stage that are adjacent in the axial direction are respectively supported by one pin (86) in a state of being radially overlapped with each other.

Description

TECHNICAL FIELD

[0001] The present application relates to an electric power tool provided with a speed reduction unit. BACKGROUND

[0002] In an electric power tool such as an impact driver, a rotation of a motor is reduced by a speed reduction unit, and the reduced rotation is transmitted to an output shaft of an anvil or the like. As the speed reduction unit, a structure is disclosed in Patent Literature 1 in which a plurality of planetary gears forming a plurality of stages in an axial direction, a gear carrier supporting the planetary gears by means of a pin, and a ring gear having an inner tooth through which the planetary gears perform a revolution are provided.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2019-98450 SUMMARY

[0006] In the conventional speed reduction unit, the ring gears of the two stages adjacent to each other in the axial direction are configured to be rotatable and selectively rotationally restricted, whereby two-stage speed reduction is achieved. In this case, the structure is formed in which one gear carrier supports the planetary gears of the two stages by means of one pin. According to this, the pin is elongated in the axial direction, which causes the speed reduction unit to become large-sized, and the pin is likely to be broken or deformed, which causes durability to be reduced.

[0007] Therefore, an object of the present application is to provide an electric power tool having a speed reduction unit which becomes compact in the axial direction and has high durability.

[0008] To achieve the above object, the present application is an electric power tool having:

[0009] a motor;

[0010] a speed reduction unit which reduces a rotation generated by the motor; and

[0011] a working unit which works by means of the rotation reduced by the speed reduction unit,

[0012] the speed reduction unit has, in the axial direction, a ring gear formed at least in two stages, a plurality of planetary gears which perform a revolution in the ring gear, and a gear carrier which supports each of the planetary gears by means of a pin,

[0013] the electric power tool is characterized in that

[0014] each of the planetary gears of a preceding stage adjacent to each other in the axial direction and each of the planetary gears of at least one stage located on a succeeding stage side are supported to one pin in a state of being radially overlapped with each other.

[0015] Inventive Effects

[0016] According to the present application, a speed reduction portion that is compact in the axial direction and has high durability can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a side view of the impact driver.

[0018] Figure 2 is a plan view of the impact driver.

[0019] Figure 3 is a rear view of the impact driver.

[0020] Figure 4 is a perspective view of the impact driver from the rear.

[0021] Figure 5 is an explanatory view of the impact driver in which the right half of the outer case is omitted and the main body is shown in a central longitudinal section.

[0022] Figure 6 is a partial perspective view of the impact driver in a state in which the rear cover is removed, Figure 6 A shows this partial perspective view from the front, Figure 6 B shows this partial perspective view from the rear.

[0023] Figure 7 is an enlarged sectional view of Figure 1 A-A line of

[0024] Figure 8 is an exploded perspective view of a main body portion of the main body outer case.

[0025] Figure 9 is an explanatory view of a working unit, Figure 9 A shows a side surface, Figure 9 B shows a front surface.

[0026] Figure 10 is an enlarged sectional view of Figure 9 C-C line of

[0027] Figure 11 is an enlarged sectional view of Figure 9 D-D line of

[0028] Figure 12 A is a partial sectional view of Figure 9 E-E line of Figure 12 B is a partial sectional view of Figure 9 F-F line of Figure 12 C is a partial sectional view of Figure 9 G-G line of

[0029] Figure 13 is Figure 1 a B-B line amplification cross-sectional view of

[0030] Figure 14 is an exploded perspective view of the deceleration section as viewed from the rear.

[0031] Figure 15 A shows a H-H line section of Figure 10 B shows an I-I line section of Figure 15 C shows a J-J line section of Figure 10 D shows a K-K line section of Figure 15 E shows an L-L line section of Figure 10 F shows an M-M line section of

[0032] Figure 16 A shows a K-K line section of Figure 10 B shows an L-L line section of Figure 16 C shows an M-M line section of Figure 10 D shows an N-N line section of Figure 16 E shows an O-O line section of Figure 10 F shows a P-P line section of

[0033] Figure 17 is an exploded perspective view of the deceleration section as viewed from the front.

[0034] Figure 18 A shows an N-N line section of Figure 10 B shows an O-O line section of Figure 18 C shows a P-P line section of Figure 10 D shows a Q-Q line section of Figure 18 E shows an R-R line section of Figure 10 F shows a S-S line section of

[0035] Figure 19 is an explanatory view of the working unit with the drill mode selected at 1, Figure 19 A shows a plan view, Figure 19 B shows a side view, Figure 19 C shows a bottom view, Figure 19 D shows a horizontal section, Figure 19 E shows a central longitudinal section.

[0036] Figure 20 is an explanatory view of the working unit with the vibration drill mode selected at 2, Figure 20 A shows a plan view, Figure 20 B shows a side view, Figure 20 C shows a bottom view, Figure 20 D shows a horizontal section, Figure 20 E shows a central longitudinal section.

[0037] Figure 21 is an explanatory view of the working unit with the impact large mode (3) selected, Figure 21 A shows a plan view, Figure 21B shows the side surface, Figure 21 C shows the bottom surface, Figure 21 D shows the horizontal cross section, Figure 21 E shows the central longitudinal cross section.

[0038] Figure 22 is an explanatory view of the working unit in which the impact small mode (4th gear) is selected, Figure 22 A shows the plan view, Figure 22 B shows the side surface, Figure 22 C shows the bottom surface, Figure 22 D shows the horizontal cross section, Figure 22 E shows the central longitudinal cross section.

[0039] Figure 23 is an exploded perspective view of the impact section.

[0040] Figure 24 A shows Figure 10 the Q-Q line cross section of the impact section, Figure 24 B shows Figure 10 the R-R line cross section of the impact section, Figure 24 C shows Figure 10 the S-S line cross section of the impact section.

[0041] Figure 25 is an exploded perspective view of the vibration section.

[0042] Figure 26 A shows Figure 10 the T-T line cross section of the vibration section, Figure 26 B shows Figure 10 the U-U line cross section of the vibration section, Figure 26 C shows Figure 10 the V-V line cross section of the vibration section.

[0043] Figure 27 is a perspective view of the working unit as viewed from below.

[0044] Figure 28 is an enlarged cross-sectional view of the W-W line of Figure 10

[0045] Figure 29 is an explanatory view of the assembly structure of the bit head, Figure 29 A shows the case where the bit head is inserted, Figure 29 B shows the case where the bit head is assembled, Figure 29 C shows the case where the bit head is pulled out.

[0046] Figure 30 A is a central longitudinal cross-sectional view of the working unit showing the state in which the inner hammer is retreated with the maximum stroke in the impact large mode, Figure 30 B is an X-X line cross-sectional view.

[0047] ​Figure 31 A is a longitudinal sectional view of a portion of an anvil provided with a bit for driving nails, Figure 31 B is an exploded perspective view of a bit for driving nails.

[0048] BRIEF DESCRIPTION OF DRAWINGS

[0049] 1 · impact driver, 2 · main body, 3 · handle, 4 · motor, 5 · working unit, 6 · mode conversion ring, 7 · hammer housing, 8 · anvil, 9 · speed switching dial, 10 · main body case, 11 · rear cover, 12 · main body portion, 13 · grip portion, 25 · controller, 30 · cover portion, 31 · screw fastening portion, 53 · rotation shaft, 60 · rear side gear housing, 61 · front side gear housing, 74 · input gear, 75 · speed reduction portion, 76 · striking portion, 77 · vibration portion, 78 · linkage switching portion, 80A to 80C · planetary gears, 81A to 81C · internal gears, 85 · rear gear carrier, 106 · speed switching retainer, 110 · speed switching plate, 114 · speed switching ring, 120 · face gear ring, 126 · upper gear, 130 · front gear carrier, 145 · speed switching wire, 151 · speed switching gear, 153 · speed switching retainer, 165 · main shaft, 166 · inner hammer, 167 · outer hammer, 168 · hammer sleeve, 169 · outer disc spring, 170 · inner disc spring, 216 · coupling ball, 230 · front side cam, 231 · rear side cam, 234 · vibration switching plate, 280 · mode conversion lever, 285 · mode conversion yoke, 295 · linkage winding portion, 301 · linkage lever, 305 · linkage cam, B · bit, B1 · bit for driving nails. DETAILED DESCRIPTION

[0050] In one embodiment of the present application, the planetary gears of the front stage can be formed so as to be provided with: a gear portion adjacent to the planetary gears of the rear stage; and a bearing portion extending toward the inner diameter side of the planetary gears of the rear stage, the planetary gears of the rear stage being fitted to the bearing portion and overlapping the same. According to this structure, the planetary gears can be overlapped compactly with each other. In addition, since the planetary gears of the rear stage do not come into contact with the pin, mechanical loss due to frictional resistance when the planetary gears of the rear stage are used can be reduced.

[0051] In one embodiment of the present application, a bearing can be provided between the bearing portion and the pin. According to this structure, two planetary gears can be supported by one bearing.

[0052] In one embodiment of the present application, the bearing can be a needle bearing. According to this structure, the radial direction becomes more compact. In addition, even if grease drying occurs, necessary lubrication can be achieved.

[0053] In one embodiment of the present application, the front-stage inner gear engaged with the front-stage planetary gears and the rear-stage inner gear engaged with the rear-stage planetary gears are arranged adjacent to each other in the axial direction with a seal member interposed between the opposing surfaces of the inner gears. In this case, the inner gears can be formed with flange portions extending toward the center side on the opposite sides of the opposing surfaces of the inner gears, respectively. According to this structure, a holding space that does not allow lubricating grease on the radially inner sides of the two inner gears to overflow to the radially outer sides is formed between the inner gears of the front stage and the rear stage, thereby preventing the lubricating grease from drying out.

[0054] In one embodiment of the present application, the front-stage inner gear and the rear-stage inner gear are each provided to be rotatable, and a rotation restriction portion that selectively restricts the rotation of the front-stage inner gear and the rear-stage inner gear is provided. According to this structure, the two speed stages can be easily realized by switching the rotation restriction of the two inner gears.

[0055] In one embodiment of the present application, the rotation restriction portion includes a stopper member arranged radially outward of the front-stage inner gear and the rear-stage inner gear and switchable to a first position in which the stopper member is stopped to the front-stage inner gear to restrict the rotation of the front-stage inner gear and a second position in which the stopper member is stopped to the rear-stage inner gear to restrict the rotation of the rear-stage inner gear. In this case, the rotation restriction portion can be formed with an operation portion that is selectively switchable to either one of the first position and the second position with respect to the stopper member. According to this structure, a speed reduction portion that is compact in the axial direction and can smoothly and stably switch the speed stages can be obtained.

[0056] In one embodiment of the present application, the stopper member is arranged such that the intermediate portion is supported and the both end portions are swingable, one end portion is stopped to the outer periphery of the front-stage inner gear in the first position, and the other end portion is stopped to the outer periphery of the rear-stage inner gear in the second position. According to this structure, the rotation restriction and release of the two inner gears can be reasonably performed with one stopper member and with a saving of space.

[0057] In one embodiment of the present application, the deceleration section can be formed so as to be housed in a cylindrical housing, and the operation section can include a ring-shaped member configured to be rotatable along the outer periphery of the housing, and first and second pressing sections alternately formed in the circumferential direction of the ring-shaped member so as to press one end of the locking member from the radially outer side of the housing to switch the locking member to the first position, and the other end of the locking member from the radially outer side to switch the locking member to the second position. In this case, the deceleration section can further include a rotation operation member configured to rotate the ring-shaped member at an arbitrary angle with respect to the outer periphery of the housing. According to this configuration, the position switching of the locking member can be performed using the ring-shaped member and the rotation operation member with ease while saving space.

[0058] In one embodiment of the present application, the ring-shaped member can be formed so as to have a plurality of teeth continuously formed in the circumferential direction thereof, and the rotation operation member can be formed so as to integrally have a gear that engages with the teeth. According to this configuration, the position switching of the locking member can be performed by the rotation operation of the rotation operation member.

[0059] In one embodiment of the present application, the ring-shaped member can be formed so as to integrally have a gear ring having teeth. According to this configuration, the teeth can be easily provided in the ring-shaped member.

[0060] In one embodiment of the present application, the ring-shaped member can be formed so as to be a frame-shaped body in which the first and second pressing sections protrude in the axial direction and extend in the circumferential direction. According to this configuration, the structure of the ring-shaped member becomes simple.

[0061] In one embodiment of the present application, a plurality of locking members can be provided. According to this configuration, the rotation restriction of the two internal gears can be reliably performed.

[0062] In one embodiment of the present application, the locking members can be disposed at a point-symmetrical position with respect to the axis of the internal gear. According to this configuration, the internal gear can be prevented from tilting and the rotation thereof can be restricted.

[0063] In one embodiment of the present application, a plurality of locking ribs extending in the axial direction can be provided at a predetermined interval along the circumferential direction of the internal gear of the front section and the internal gear of the rear section. In this case, locking portions that lock the locking ribs in the circumferential direction can be formed at both ends of the locking member. According to this configuration, the rotation restriction and release of the internal gears can be reliably performed.

[0064] In one embodiment of the present application, the locking portion can be formed in a curled shape. According to this configuration, the locking portion is easily locked with the locking rib.

[0065] Embodiment

[0066] Hereinafter, an embodiment of the present application will be described based on the drawings.

[0067] (Summary of impact driver and explanation of housing structure)

[0068] Figure 1 is a side view of a rechargeable impact driver as an example of a work tool and an electric power tool, and further an impact tool. Figure 2 is a plan view of the impact driver. Figure 3 is a rear view of the impact driver. Figure 4 is a perspective view of the impact driver as viewed from the rear. Figure 5 is an explanatory view of the impact driver in which a half-cut housing on the right is omitted and the main body is shown in a central longitudinal section.

[0069] The impact driver 1 has a main body 2 and a handle 3. The main body 2 is formed with a center axis in the front-rear direction. A motor 4 and a work unit 5 are provided inside the main body 2. The work unit 5 is provided with a mode conversion ring 6 exposed to the outside in the front portion. A hammer housing 7 is provided on the front side of the mode conversion ring 6 so as to be exposed to the front. The work unit 5 is provided with an anvil 8 protruding forward from the center of the hammer housing 7. A speed switch dial 9 is provided on the upper surface of the work unit 5 so as to be rotatably operated and exposed upward. The handle 3 protrudes downward from the main body 2. A bumper 43 made of rubber is attached to the front surface of the hammer housing 7.

[0070] The impact driver 1 is provided with a main body housing 10, a rear cover 11, and the hammer housing 7 as a housing. The main body housing 10 includes a main body portion 12, a grip portion 13, a guard portion 14, and a battery attachment portion 15. The main body portion 12 is formed in a cylindrical shape and forms a middle portion of the main body 2 other than the front and rear ends. A plurality of air inlets 16, 16,... are formed in the left and right rear portions of the main body portion 12. The main body portion 12 holds the motor 4 and the work unit 5 and causes the mode conversion ring 6 and the hammer housing 7 to be exposed on the front side.

[0071] The grip portion 13 is formed downward from the rear end of the main body portion 12 and forms the rear side of the handle 3. A switch 17 is provided on the upper end of the grip portion 13. The switch 17 causes a trigger 18 to protrude forward. The grip portion 13 is located at the rear end of the main body portion 12. Accordingly, it is easy to hold the root of the grip portion 13 and press the main body 2 forward. A forward-reverse switch button 19 of the motor 4 is provided on the upper side of the switch 17.

[0072] The guard portion 14 is formed downward from the front end of the main body portion 12 to form the front side of the handle 3. The guard portion 14 is formed with a smaller left-right width than the grip portion 13 and overlaps the grip portion 13 in the front view. The upper end of the guard portion 14 is a standing portion 20 that extends in a curved shape to the lower side of the anvil 8 in front of the main body 2. A lamp 21 is provided at the upper end of the standing portion 20. The lamp 21 irradiates the front of the anvil 8. A wire storage space 22 is formed in the interior of the guard portion 14. The wire storage space 22 stores, for example, an unillustrated wire that electrically connects the controller 25 and the lamp 21 and the like to be described later, and a sensor.

[0073] The battery mounting portion 15 links the lower end of the grip portion 13 and the lower end of the guard portion 14. Accordingly, the handle 3 is formed in a ring shape. A battery pack 23 that is a power source is slidably mounted in the battery mounting portion 15 from the front. A terminal block 24 and a controller 25 are provided in the battery mounting portion 15. The battery pack 23 is electrically connected to the terminal block 24. The controller 25 has a control circuit board 26. The controller 25 performs various controls such as control of the motor 4 and monitoring of the remaining capacity of the battery pack 23. In addition, the controller 25 also has an electronic clutch function, that is, in the case where the output torque reaches a prescribed value or more, the rotation of the motor 4 is stopped.

[0074] A display portion 27 is provided on the inner side of the guard portion 14. The display portion 27 is electrically connected to the control circuit board 26 by means of an unillustrated wire. The display portion 27 displays the remaining capacity of the battery pack 23, the number of stages of the electronic clutch, and the like. The display portion 27 is formed by a touch panel and the number of stages of the electronic clutch can be selected by a touch operation on the display portion 27.

[0075] The main body case 10 and the rear cover 11 are made of resin. The main body case 10 is divided into left and right half-cut cases 10a, 10b and assembled together from the right side by a plurality of screws 28, 28,....

[0076] The rear cover 11 has a cover portion 30 and a screw fastening portion 31. The cover portion 30 is circular in the rear view and, as shown in Figure 6 the drawing, the cover portion 30 covers and is connected to a cylindrical portion 32 formed at the rear end of the main body portion 12 from the rear. A plurality of exhaust ports 33, 33,... are formed in the peripheral surface of the cover portion 30. The exhaust ports 33 are each a long circular shape that extends in the peripheral direction of the cover portion 30. However, in the upper half portion of the cover portion 30, as shown in Figure 7As shown, one circumferentially longer exhaust port 33A (referred to as "33A" for distinction) is formed on each side. In the lower half of the cover 30, two circumferentially shorter exhaust ports 33B (referred to as "33B" for distinction) are formed on each side. Regarding the two exhaust ports 33A and 33A in the upper half, their circumferentially adjacent inner edges 34a and 34a are formed vertically. Their circumferentially separated inner edges 34b and 34b are formed horizontally. The inner edges of the four exhaust ports 33B in the lower half are formed horizontally, parallel to the inner edges 34b.

[0077] A fan 35 is disposed inside the cover 30 and mounted on the rotating shaft 53 of the motor 4. Regardless of whether the fan 35 rotates forward or backward, air is guided upward by the inner edges 34a and 34a at the two exhaust ports 33A and 33A.

[0078] A screw fastening portion 31 is formed downward from the lower part of the cover portion 30. An anti-rotation portion 36 extending vertically is provided on the rear surface of the main body portion 12 and protruding below the cylindrical portion 32. An internal thread portion 37 is formed on the upper center side of the anti-rotation portion 36. A through hole 38 opening at the rear is formed below the internal thread portion 37. The through hole 38 is used for the passage of wiring from the grip portion 13 below and inside the main body 2.

[0079] The screw fastening part 31 has a pair of ribs 39, 39 on its front surface that engage with the anti-rotation part 36 from the left and right sides. A circular through hole 40 is provided between the ribs 39, 39.

[0080] Accordingly, when assembling the rear cover 11, the cover portion 30 is fitted into the cylindrical portion 32, and the ribs 39, 39 of the screw fastening portion 31 are fitted into the anti-rotation portion 36. In this state, the screw 41, which passes through the rear through hole 40, is screwed into the internal thread portion 37. Thus, the rear cover 11 is assembled using only one screw 41.

[0081] (Explanation of the entity's internal structure)

[0082] Motor 4 is an internal rotor type brushless motor with a stator 45 and a rotor 46. Insulating components 47 are provided before and after the stator 45. Figure 8 As shown, two positioning recesses 48, 48 are formed on the left and right sides of the front insulating member 47, respectively. A terminal unit 49 is provided at the lower part of the front insulating member 47. The terminal unit 49 is electrically connected to a plurality of coils 50, 50... wound around the stator 45 by means of the insulating members 47, 47. A wire is connected to the terminal unit 49 and disposed between it and the controller 25.

[0083] On the inner surfaces of the half-cut housings 10a, 10b on the left and right of the main body portion 12, two upper and lower locking claws 51, 51 that are locked in the positioning recesses 48, 48 are provided in a protruding manner. Behind the locking claws 51, 51 and on the inner surfaces of the half-cut housings 10a, 10b, support ribs 52 that follow the circumferential surface of the stator 45 are respectively provided. Due to this, the stator 45 is held at the rear portion of the main body portion 12.

[0084] The rotor 46 has a rotation shaft 53 at the center and penetrates the stator 45. The rear end of the rotation shaft 53 is supported by a bearing 54 at the center of the cover portion 30 of the rear cover 11. The fan 35 is provided on the rotation shaft 53 on the front side of the bearing 54, so as to overlap the bearing 54 in the radial direction. A pinion 55 is formed on the front end of the rotation shaft 53.

[0085] As shown in Figure 9 and Figure 10 , Figure 11 , the working unit 5 has a rear-side gear housing 60 and a front-side gear housing 61.

[0086] The rear-side gear housing 60 is formed in a bottomed cylindrical shape with the rear surface closed by a rear plate portion 62 and the front end open. The front-side gear housing 61 is formed in a bottomed cylindrical shape with the front surface closed by a front plate portion 63 and the rear end open. The front-side gear housing 61 is formed to have a larger diameter than the rear-side gear housing 60, and the open rear end is fitted to the front end of the rear-side gear housing 60. On the left and right side surfaces of the rear-side gear housing 60, two upper and lower rear stoppers 64, 64 for the rear end of the front-side gear housing 61 to abut against are respectively formed. Figure 8 , Figure 9 A). Between the rear stoppers 64, 64 and on the left and right side surfaces of the rear-side gear housing 60, half-cylinder portions 65, 65 that are open at the front are provided in a protruding manner in the front-rear direction.

[0087] On the left and right side surfaces of the front-side gear housing 61, front stoppers 66, 66 that abut against the half-cylinder portions 65, 65 from above are respectively formed. Due to this, the front-side gear housing 61 is in a state where the movement toward the rear is restricted by the rear stoppers 64 and the rotation in the circumferential direction is restricted by the half-cylinder portions 65.

[0088] As shown in Figure 12 A and Figure 13 , the hammer housing 7 is fixed to the front plate portion 63 from the rear by a plurality of screws 67, 67, … The mode conversion ring 6 is supported so as to be rotatable between the front plate portion 63 and the hammer housing 7.

[0089] On the front portion of the rear-side gear housing 60 and on the left and right side surfaces, four rear-side locking recesses 68, 68, … are respectively provided. The rear-side locking recesses 68 are respectively provided in the front-rear direction at a predetermined interval in the circumferential direction of the rear-side gear housing 60. Also as shown in Figure 8 and Figure 13As shown, two front locking recesses 69 are arranged circumferentially on the upper front part of the front gear housing 61 and on the rear side of the mode conversion ring 6. Each front locking recess 69 opens to the left and right outwards.

[0090] Four rear-side locking portions 70, 70... are provided on the rear part of the main body 12 and on the inner surface of the left and right half-cut outer shells 10a, 10b, which are locked to each of the rear-side locking recesses 68. Two front-side locking portions 71, 71 are provided on the front part of the main body 12 and on the inner surface of the left and right sides, which are locked to each of the front-side locking recesses 69.

[0091] Accordingly, the front and rear locking portions 70 and 71 are respectively locked into the front and rear locking recesses 68 and 69, thereby keeping the working unit 5 in the main body 12 in a state where its rotation and forward and backward movement are restricted.

[0092] In particular, such as Figure 13 As shown, the front gear housing 61 is clamped to the left and right half-shells 10a and 10b at a position higher than when viewed from the front axis in the left-right direction. Accordingly, it is possible to ensure that a large linkage switching part 78 with a circumferential angle of more than 180° is provided on the lower side of the clamping part and between the front gear housing 61 and the main body 12.

[0093] A thick-walled portion 72, which is circular in frontal view, is formed at the center of the rear plate portion 62 of the rear gear housing 60. An input gear 74 is held in the thick-walled portion 72 by means of a bearing 73. The input gear 74 is configured such that it meshes with the rear portion of a pinion 55 of the rotating shaft 53, thereby enabling it to rotate integrally with the rotating shaft 53. The input gear 74 has a first gear portion 74a on its rear side and a second gear portion 74b on its front side, with a diameter smaller than that of the first gear portion 74a.

[0094] The working unit 5 is provided with a deceleration unit 75, a striking unit 76, a vibration unit 77, and a linkage switching unit 78 for linking and switching these working units from the rear. These will be described in turn below.

[0095] (1) Description of the deceleration section

[0096] The reduction gear 75 is disposed within the rear gear housing 60. Also, Figure 14 As shown, the reduction unit 75 has three planetary gears 80, 80... arranged in the axial direction to form three stages, and an internal gear 81 for meshing with each planetary gear 80. The reduction ratio is different for each stage. Hereinafter, starting from the last stage (first stage), the gears will be labeled A to C sequentially, such as 80A (first stage), 80B (second stage), and 80C (third stage). A engagement ring 82 is provided between the internal gear 81B of the second stage and the internal gear 81C of the third stage.

[0097] As Figure 10 , Figure 11 , Figure 15 As shown in FIG. 8A, the first-stage planetary gears 80A mesh with the first-stage ring gear 81 A and the first gear portion 74a of the input gear 74. Each planetary gear 80A has a gear portion 83 on the rear side and a small-diameter bearing portion 84 on the front side.

[0098] The second-stage planetary gears 80B are fitted to the bearing portions 84 of the first-stage planetary gears 80A. In this way, the first-stage and second-stage planetary gears 80A, 80B are radially overlapped with each other. As shown in FIG. 8B, the planetary gears 80B mesh with the second-stage ring gear 81B and the second gear portion 74b of the input gear 74. Figure 15

[0099] A rear gear carrier 85 in the shape of a disc is provided on the front side of the planetary gears 80B. The rear gear carrier 85 has three pins 86, 86... projecting toward the rear. The bearing portions 84 of the planetary gears 80A are supported to the respective pins 86 by bearings (in this case, needle bearings) 87. A spur gear 88 is coupled to the central spline of the rear gear carrier 85 and projects toward the front.

[0100] In this way, the planetary gears 80A, 80B rotating in the same direction by the input gear 74 are radially overlapped with each other, so that the shaft length including the two planetary gears 80A, 80B is shortened and the pins 86 can be shortened. One bearing 87 is sufficient. In addition, the contact length of the planetary gears 80A with the pins 86 can be shortened, so that mechanical loss due to frictional resistance is reduced.

[0101] In particular, the support portion of the planetary gears 80B is made the bearing portion 84 of the planetary gears 80A, so that the relative angular velocity of the planetary gears 80A to the planetary gears 80B is slower than the relative angular velocity of the planetary gears 80B to the pins 86. In this way, mechanical loss at the time of deceleration by the planetary gears 80B can be reduced. That is, mechanical loss is reduced when the planetary gears 80B contact the planetary gears 80A rotating in the same direction even at a slower speed than when the planetary gears 80B contact the non-rotating pins 86.

[0102] The first-stage ring gear 81A is disposed on the front side of the rear plate portion 62 of the rear-side gear housing 60 with the washer 89 interposed therebetween in a rotatable manner. A rear flange portion 90 tapered toward the center side is formed on the rear side of the inner tooth portion of the ring gear 81A. The rear flange portion 90 is close to the outer peripheral surface of the thick wall portion 72 of the rear plate portion 62. A plurality of rear locking ribs 91, 91... are provided on the outer periphery of the ring gear 81A. Figure 14 and Figure 15 As shown in FIG. 8A, the rear locking ribs 91 are provided in the front-rear direction at equal intervals in the circumferential direction. A ring-shaped holding groove 92 is coaxially formed on the front surface of the ring gear 81A. As shown in FIG. 8B, the holding groove 92 is engaged with the holding pin 82 of the input gear 74. Figure 15 ​As shown in Figure B, an O-ring 93 is housed in the retaining groove 92.

[0103] The second-stage internal gear 81B has more internal teeth than the internal gear 81A. The internal gear 81B is adjacent to the internal gear 81A in the axial direction and is pressed against the O-ring 93. The internal gear 81B is also configured to rotate.

[0104] A front flange 94, with a reduced diameter towards the center, is formed on the front side of the internal teeth of the internal gear 81B. The front flange 94 is close to the outer peripheral surface of the rear gear carrier 85. Furthermore... Figure 14 and Figure 16 As shown in Figure A, a plurality of front locking ribs 95 are provided on the outer periphery of the internal gear 81B. The front locking ribs 95 are arranged in the front-rear direction with the same spacing as the rear locking ribs 91 in the circumferential direction.

[0105] Thus, as Figure 11 As shown, a retaining space S is formed between the internal gears 81A and 81B by the rear flange 90, the front flange 94, and the O-ring 93, preventing grease from overflowing outwards from the radially inner side of the internal gears 81A and 81B. This prevents the grease from drying out. It should be noted that even if the grease dries out, lubrication can be maintained because the bearing 87 of the planetary gear 80A is a needle roller bearing.

[0106] The engaging ring 82 is housed within the rear gear housing 60 on the front side of the internal gear 81B. The engaging ring 82 has multiple engaging claws 100, 100... on its outer circumference. Each engaging claw 100 is equally spaced circumferentially and protrudes radially outward, extending forward. Figure 16 B and Figure 17 As shown, a plurality of engaging grooves 101, 101... are provided on the inner circumferential surface of the rear gear housing 60. Each engaging groove 101 extends from the front end of the rear gear housing 60 to the rear. Each engaging claw 100 of the engaging ring 82 engages with each engaging groove 101 from the front.

[0107] Accordingly, the engagement ring 82 is restricted from rotating within the rear gear housing 60. Protrusions 102, 102 protruding radially outward are provided on the left and right sides of the engagement ring 82 and on the outer surfaces of the engagement claws 100, 100. The protrusions 102, 102 engage with through holes 108, 108 provided in the speed switching retainers 106, 106 (described later). The speed switching retainers 106, 106 have their forward and backward movement restricted within the rear gear housing 60 by the bracket plate 136 (described later). Accordingly, the forward movement of the engagement ring 82 is restricted, and the forward movement of the internal gears 81A, 81B is also restricted.

[0108] Openings 103, 103 are formed on the left and right sides of the rear gear housing 60 and on the rear side of the semi-cylindrical portions 65, 65 in the front-rear direction. Slits 104, 104 are formed on the inner side of the semi-cylindrical portions 65, 65 in the front-rear direction. Each slit 104 opens at the front end of the rear gear housing 60.

[0109] like Figure 17 and Figure 18 As shown in Figure A, a pair of grooves 105, 105 extending in the front-rear direction are formed on the inner circumferential surface of the rear gear housing 60, inside the openings 103, 103. Speed ​​switching retainers 106, 106 are provided in the grooves 105, 105. The speed switching retainer 106 is formed as a plate that fits into the groove 105 and extends in the front-rear direction. A pair of square holes 107, 107 are formed at the rear of the speed switching retainer 106. The square holes 107, 107 are located inside the openings 103, 103. A through hole 108 is formed on the front side of the square holes 107, 107 and on the speed switching retainer 106 for the protrusion 102 of the engagement ring 82 to be engaged. An inner slit 109 is formed at the front of the through hole 108, cutting into the rear from the front end of the speed switching retainer 106.

[0110] Speed ​​switching plates 110 are provided on the rear outer side of the speed switching retainers 106, 106. The speed switching plate 110 is a plate-shaped structure that spans the front and rear of the speed switching retainer 106 through square holes 107, 107 and extends in the front-rear direction. For example... Figure 11 As shown, regarding the speed switching plate 110, the central portion in the front-to-back direction abuts against the spacer wall 111 between the square holes 107, 107 of the speed switching retainer 106. A rear locking portion 112 and a front locking portion 113 are provided at both the front and rear ends of the speed switching plate 110. The two locking portions 112 and 113 are formed such that they are bent into a coiled shape towards the center side of the rear gear housing 60.

[0111] Accordingly, each speed switching plate 110 can alternately swing inward within the opening 103 of the rear gear housing 60, using its central portion abutting against the partition wall 111 as a fulcrum. The outer periphery of the first-stage internal gear 81A is located inside the rear locking portion 112. When the rear locking portion 112 swings inward toward the rear gear housing 60, it can be locked against the rear locking rib 91 by means of the rear square hole 107. At this time, the opposite front locking portion 113 protrudes outward beyond the opening 103 and separates from the outer periphery of the internal gear 81A. The outer periphery of the second-stage internal gear 81B is located inside the front locking portion 113. When the front locking portion 113 swings inward toward the rear gear housing 60, it can be locked against the front locking rib 95 by means of the front square hole 107. At this time, the opposite rear locking portion 112 protrudes outward beyond the opening 103 and separates from the outer periphery of the internal gear 81B.

[0112] A speed switching ring 114 is rotatably provided outside the speed switching plate 110 and at the outer periphery of the rear side gear case 60. The speed switching ring 114 is a frame-shaped body extending in the front-rear direction while being continuous in the circumferential direction. The speed switching ring 114 has: ten rear pressing portions 115, 115,... extending in the circumferential direction on the rear side; and ten front pressing portions 116, 116,... extending in the circumferential direction on the front side. The rear pressing portions 115 and the front pressing portions 116 are alternately arranged in the circumferential direction, and adjacent pressing portions 115, 116 are connected to each other by inclined portions 117, 117,.... A virtual circle including each of the rear pressing portions 115 is located outside the rear locking portions 112, 112 of the speed switching plates 110, 110. A virtual circle including each of the front pressing portions 116 is located outside the front locking portions 113, 113 of the speed switching plates 110, 110.

[0113] Accordingly, when the speed switching ring 114 is rotated, the phases are alternately switched in which the rear pressing portions 115 are located outside the rear ends of the speed switching plates 110 and in which the front pressing portions 116 are located outside the front ends of the speed switching plates 110. If the rear pressing portions 115 are located outside the rear ends of the speed switching plates 110, the rear pressing portions 115 press the rear ends of the speed switching plates 110 toward the inside. Accordingly, the speed switching plates 110 are swung so that the rear locking portions 112 are locked to the rear inclined ribs 91 of the first stage of the inner gears 81A. Thus, the rotation of the inner gears 81A is restricted. On the other hand, if the front pressing portions 116 are located outside the front ends of the speed switching plates 110, the front pressing portions 116 press the front ends of the speed switching plates 110 toward the inside. Accordingly, the speed switching plates 110 are swung so that the front locking portions 113 are locked to the front inclined ribs 95 of the second stage of the inner gears 81B. Thus, the rotation of the inner gears 81B is restricted. The speed switching plates 110, 110 on the left and right sides are synchronously swung.

[0114] Between the two phases, when the inclined portions 117 pass outside the speed switching plates 110, the speed switching plates 110 are pressed toward the inside to change between the front inclined posture and the rear inclined posture.

[0115] A speed switching ring 114 is combined with the front of the speed switching ring 114. The speed switching ring 114 is a ring body having the same diameter as the speed switching ring 114. A plurality of teeth 121, 121,... protruding forward are continuously formed at equal intervals in the circumferential direction on the front surface of the speed switching ring 120. A plurality of cutouts 122, 122,... are formed on the rear surface of the speed switching ring 120. Each cutout 122 corresponds to the front pressing portion 116 of the speed switching ring 114. An engagement protrusion 123 that engages with the corresponding cutout 122 is formed in each front pressing portion 116. Accordingly, the speed switching ring 120 and the speed switching ring 114 are integrated in the rotational direction.

[0116] The speed switching ring 114 is rotated by the speed switching dial 9. The speed switching dial 9 is disc-shaped when viewed from above. As shown in Figure 10 An upper support protrusion 124 protruding upward is provided on the upper surface of the rear gear housing 60. A receiving hole 125 into which the upper support protrusion 124 is inserted is formed in the center of the lower surface of the speed switching dial 9. Accordingly, the speed switching dial 9 can be rotated with the upper support protrusion 124 as the center. An upper gear 126 is provided coaxially on the lower surface of the speed switching dial 9. As shown in Figure 18 A, the upper gear 126 engages with the teeth 121 of the speed switching ring 120. A knob portion 127 protruding in the diametrical direction is provided on the upper surface of the speed switching dial 9.

[0117] As shown in Figure 16 C, each planetary gear 80C of the third stage is disposed on the front side of the rear gear carrier 85 and engages with the spur gear 88. Each planetary gear 80C is supported to the disc-shaped front gear carrier 130 by means of a pin 131, 131,.... Here, the pin 131 is shortened in the axial direction, and the planetary gear 80C and the front gear carrier 130 directly abut. Accordingly, the bending moment of the pin 131 is reduced, and breakage is less likely to occur.

[0118] A plurality of outer engagement teeth 132, 132,... are formed on the front portion of the outer periphery of the front gear carrier 130. The rear end of the main shaft 165 to be described later is combined with the central spline of the front gear carrier 130. The front gear carrier 130 is less likely to be affected by the twisting of the main shaft 165 due to the spline combination. Accordingly, it is less likely that an impact load directed to each gear or pin is applied from the main shaft 165 side, and the durability of the reduction unit 75 is improved. As shown in Figure 10 and Figure 17 A ring-shaped recess 133 is formed on the front surface of the front gear carrier 130 around the main shaft 165.

[0119] The third stage sun gear 81C is configured to be movable forward and backward within the rear side gear housing 60. A plurality of engagement ribs 134, 134... are provided on the rear portion of the outer periphery of the sun gear 81C. The engagement ribs 134 are formed in the same number (10) as the engagement claws 100 of the engagement ring 82. An annular groove 135 is formed on the front portion of the outer periphery of the sun gear 81C.

[0120] When the sun gear 81C is in the rearward position, the state of engagement of the internal teeth with the planetary gear 80C is maintained, so that the engagement ribs 134 are engaged with the engagement claws 100 of the engagement ring 82 in the circumferential direction. Accordingly, the rotation of the sun gear 81C is restricted. When the sun gear 81C is in the forward position, as shown in FIG. 6, the sun gear 81C is separated from the engagement ring 82, so that the internal teeth are engaged with the planetary gear 80C and the external engagement teeth 132 of the front gear carrier 130. Figure 11

[0121] A carrier plate 136 is provided on the front side of the sun gear 81C. The carrier plate 136 supports the rear end of the main shaft 165 by means of a bearing 137. The carrier plate 136 has an annular bearing locking portion 138 protruding rearward on the outer periphery of the holding portion of the bearing 137. The carrier plate 136 has a plurality of engagement protrusions 139, 139... at equal intervals in the circumferential direction on the outer periphery. Each of the engagement protrusions 139 is engaged with a wide portion 140 (see FIG. 8) of the front end of each of the engagement grooves 101 provided on the inner peripheral surface of the rear side gear housing 60. Accordingly, the rotation and movement rearward of the carrier plate 136 within the rear side gear housing 60 are restricted. Figure 17

[0122] As shown in FIG. 7, the bearing locking portion 138 protrudes into a recessed portion 133 provided on the front surface of the front gear carrier 130. Accordingly, the front gear carrier 130 and the bearing locking portion 138 overlap in the radial direction, so that the axial direction becomes compact. An annular avoidance recessed portion 141 (see FIG. 8) is also formed on the front surface of the carrier plate 136 on the outer peripheral side of the bearing 137. Figure 10 Figure 17

[0123] Figure 11 Figure 18 ​​​​​​As shown in FIG. 1, the speed switching wire 145 is engaged with the recess 135 of the third stage of the inner gear 81C. The speed switching wire 145 is provided to the lower outer side of the front side gear housing 61. The speed switching wire 145 is formed in a semicircular shape in the front view, and the left and right ends are folded back portions 146, 146. The folded back portions 146, 146 are inserted from the front into the left and right semicylindrical portions 65, 65 of the rear side gear housing 60. The rear ends of the folded back portions 146, 146 are stopper end portions 147, 147 that are folded toward the center side of the rear side gear housing 60 within the semicylindrical portions 65, 65. The stopper end portions 147, 147 pass through the slits 104, 104 of the rear side gear housing 60, and then pass through the inner slits 109, 109 of the speed switching holders 106, 106, thereby being engaged with the recess 135 of the inner gear 81C. A pair of left and right U-shaped protrusions 148, 148 that protrude downward are formed in the lower portion of the speed switching wire 145 and in the center in the left and right directions.

[0124] A pair of left and right stop protrusions 149, 149 are provided to protrude outward from the outer circumferential surfaces of the engagement protrusions 139, 139 on the left and right sides of the bracket plate 136. The stop protrusions 149, 149 are positioned in front of the slits 104, 104 of the rear side gear housing 60 to prevent the stopper end portions 147, 147 from disengaging.

[0125] As shown in FIG. 1, the speed switching wire 145 is engaged with the recess 135 of the third stage of the inner gear 81C. The speed switching wire 145 is provided to the lower outer side of the front side gear housing 61. The speed switching wire 145 is formed in a semicircular shape in the front view, and the left and right ends are folded back portions 146, 146. The folded back portions 146, 146 are inserted from the front into the left and right semicylindrical portions 65, 65 of the rear side gear housing 60. The rear ends of the folded back portions 146, 146 are stopper end portions 147, 147 that are folded toward the center side of the rear side gear housing 60 within the semicylindrical portions 65, 65. The stopper end portions 147, 147 pass through the slits 104, 104 of the rear side gear housing 60, and then pass through the inner slits 109, 109 of the speed switching holders 106, 106, thereby being engaged with the recess 135 of the inner gear 81C. A pair of left and right U-shaped protrusions 148, 148 that protrude downward are formed in the lower portion of the speed switching wire 145 and in the center in the left and right directions. Figure 10 Figure 14 A lower support protrusion 150 is provided to protrude downward from the lower surface of the rear side gear housing 60, as shown in FIG. 1. The lower support protrusion 150 is coaxially arranged with the upper support protrusion 124. A speed switching gear 151 is rotatably attached to the lower support protrusion 150. The speed switching gear 151 is formed in the same size and number of teeth as the upper gear 126 of the speed switching dial 9, and is engaged with the teeth 121 of the flat gear ring 120. An eccentric pin 152 is provided to protrude downward from the lower surface of the speed switching gear 151 at an eccentric position.

[0126] A speed switching holder 153 is provided to the lower side of the speed switching gear 151. The speed switching holder 153 is supported to be movable forward and backward on the receiving seat 42 (shown in FIG. 1) formed in the inner bottom surface of the main body 12. Figure 5 Figure 8 The speed switching holder 153 is a plate-shaped member extending in the front and rear directions, and a long hole 154 extending in the left and right directions is formed in the rear portion. The eccentric pin 152 of the speed switching gear 151 is inserted into the long hole 154 from above. The center portion of the long hole 154 in the left and right directions is a circular portion 155 bulging in the front and rear directions. The rear end of the speed switching holder 153 is a stopper 156 folded upward.

[0127] ​​A guide protrusion 157 is provided upward on the front side of the long hole 154 and on the upper surface of the speed switching holder 153. The guide protrusion 157 extends in the left-right direction.

[0128] A pair of holding plates 159, 159 is integrally formed on the front side of the guide protrusion 157 and on the front portion of the speed switching holder 153. The holding plates 159, 159 extend in the left-right direction with a space apart in the front-rear direction. A pair of link plates 160, 160 extending in the front-rear direction and linking the holding plates 159, 159 to each other is formed between the holding plates 159, 159. The protrusion portions 148, 148 of the speed switching wire 145 are engaged with the link plates 160, 160 from below. Accordingly, the speed switching wire 145 is held between the holding plates 159, 159 and is formed integrally with the speed switching holder 153 in the front-rear direction.

[0129] With respect to the deceleration portion 75, the speed switching dial 9 on the upper side is rotated by the knob portion 127. Then, the face gear ring 120 and the speed switching ring 114 are rotated by the upper gear 126. Here, when the speed switching dial 9 is rotated by 90°, the face gear ring 120 and the speed switching ring 114 are rotated by 18°. Accordingly, the rotation of the speed switching dial 9 is alternately switched to the swing of the speed switching plates 110, 110 to the rear inclined posture based on the rear pressing portions 115, 115 and the swing of the speed switching plates 110, 110 to the front inclined posture based on the front pressing portions 116, 116 every time the speed switching dial is rotated by 90°. That is, the rotation restriction of the first stage of the inner gear 81A based on the rear pressing portion 115 and the rotation restriction of the second stage of the inner gear 81B based on the front pressing portion 116 are switched every time the upper gear 126 is rotated by 90°.

[0130] When the upper gear 126 is rotated, the speed switching gear 151 is also rotated in the opposite direction by the face gear ring 120 at the same time. The rotation amount (angle) is the same as that of the upper gear 126. Then, the eccentric pin 152 performs eccentric motion and the speed switching holder 153 is slid in the front-rear direction by the long hole 154. Accordingly, the speed switching wire 145 is integrally moved in the front-rear direction and the engaged end portion 147 is engaged with the inner gear 81C of the third stage of the recess 135. Here, the speed switching holder 153 is slid to the front or the rear every time the upper gear 126 is rotated by 180°. Accordingly, the inner gear 81C is switched between the forward position and the rearward position by the speed switching wire 145.

[0131] The left and right ends of the speed switching wire 145 become bent portions 146, 146 bent toward the rear, which are inserted from the front ends of the half-tube portions 65, 65 and extend toward the rear. Thereby, the inner gear 81C can be made to move linearly in the axial direction. In addition, the bent portions 146, 146 are prevented from being deflected toward the outside by the half-tube portions 65, 65, and thus the locking end portions 147, 147 are difficult to be disengaged from the grooves 135. Further, since the half-tube portions 65, 65 are open only in the front direction, leakage of lubricating grease is difficult to occur.

[0132] Thus, with respect to the speed reduction portion 75, with each 90° rotation of the speed switching dial 9, the rotation restriction of the first- and second-stage inner gears 81A, 81B and its release and the forward and rearward positions of the third-stage inner gear 81C are combined to enable selection of the 1st-4th gear shift stages. The numbers 1-4 indicating the speeds are written every 90° on the upper surface of the speed switching dial 9. Cutout portions 161 are formed on the outer periphery of the speed switching dial 9 respectively outside the numbers in the radial direction. A plate spring 162 held on the upper surface of the front-side gear housing 61 in the left and right directions Figure 9 、 Figure 14 ) can be locked to the cutout portions 161. Thereby, a click action is obtained each time the speed switching dial 9 is rotated by 90°.

[0133] In addition, as shown in Figure 14 and Figure 16 A, a plurality of click concave portions 118, 118 are formed on the outer periphery of the rear-side gear housing 60. Click convex portions 119 engaging with the click concave portions 118 in the rotational direction are formed on the inner periphery sides of the respective rear press portions 115 and the respective front press portions 116 of the speed switching ring 114. Thereby, when the speed switching ring 114 is rotated, a click action is obtained by the engagement of the click concave portions 118 and the click convex portions 119.

[0134] Figure 19 The 1st gear is shown. In the rotational position of the speed switching dial 9, as shown in Figure 19 D, the speed switching plate 110 is in a forward inclined posture. Thereby, the rotation of the second-stage inner gear 81B is restricted, and the first-stage inner gear 81A is freely rotated. At this time, as shown in Figure 19 C, the speed switching gear 151 is in a first rotational position in which the eccentric pin 152 is located to the left rear. Thereby, the speed switching holder 153 is in a retracted position and the third-stage inner gear 81C is located in the retracted position. Thereby, the inner gear 81C is engaged with the engagement ring 82 to be restricted from rotating.

[0135] Rotation input from the input gear 74 is transmitted to the first-stage planetary gear 80A and the second-stage planetary gear 80B. However, the first-stage ring gear 81A freely rotates, and rotation of the second-stage ring gear 81B is restricted. Accordingly, the planetary gear 80A does not perform revolution, and only the second-stage planetary gear 80B, which has a larger reduction ratio, performs revolution in the ring gear 81B. Rotation of the rear gear carrier 85, which rotates due to revolution of the planetary gear 80B, is transmitted to the third-stage planetary gear 80C to cause it to perform revolution in the ring gear 81C. Rotation of the front gear carrier 130, which rotates due to revolution of the planetary gear 80C, is transmitted to the main shaft 165.

[0136] Figure 20 The 2nd speed is shown. The speed switch dial 9 is rotated 90° to the right in plan view from the 1st speed. At this rotational position of the speed switch dial 9, the flat gear ring 120 is rotated by 18° to cause the speed switch plate 110 to be formed in a rearward inclined posture. Accordingly, rotation of the first-stage ring gear 81A is restricted, and the second-stage ring gear 81B freely rotates. At this time, the speed switch gear 151 is rotated 90° to the left in plan view, and as shown in Fig. C, is in the second rotational position in which the eccentric pin 152 is located to the right rear. Accordingly, the retracted position of the speed switch holder 153 does not change, and the ring gear 81C is also restricted in rotation in the retracted position engaged with the engagement ring 82. Note that, when the eccentric pin 152 is rotated by 90°, it moves along a circular arc-shaped locus bulging to the rear side, but the central portion of the long hole 154 of the speed switch holder 153 is increased in width in the front-rear direction by the circular portion 155, and thus rotation of the eccentric pin 152 is permitted. In addition, excessive load is not applied to the speed switch holder 153. Figure 20

[0137] Accordingly, rotation input from the input gear 74 is transmitted to the planetary gear 80A and the planetary gear 80B, but the planetary gear 80B does not perform revolution, and only the first-stage planetary gear 80A, which has a smaller reduction ratio, performs revolution in the ring gear 81A. Rotation of the rear gear carrier 85, which rotates due to revolution of the planetary gear 80A, is transmitted to the third-stage planetary gear 80C to cause it to perform revolution in the ring gear 81C. Rotation of the front gear carrier 130, which rotates due to revolution of the planetary gear 80C, is transmitted to the main shaft 165 at a speed greater than that in the 1st speed.

[0138] Figure 21 The 3rd speed is shown. The speed switch dial 9 is rotated 90° to the right in plan view from the 2nd speed. At this rotational position of the speed switch dial 9, the flat gear ring 120 is rotated by 18° to cause the speed switch plate 110 to be formed in the same forward inclined posture as in the 1st speed. Accordingly, rotation of the second-stage ring gear 81B is restricted, and the first-stage ring gear 81A freely rotates.

[0139] ​At this time, the speed switching gear 151 is rotated 90° to the left from 2nd gear in plan view, as shown in Fig. 10C, to a fourth rotational position in which the eccentric pin 152 is located in front of the left side. Accordingly, the speed switching holder 153 and the inner gear 81C are still in the advanced position. Figure 21 C, the third stage planetary gear 80C and the front gear carrier 130 are formed in a unit in the rotational direction due to the inner gear 81C which freely rotates.

[0140] Accordingly, the rotation input from the input gear 74 is transmitted to the planetary gears 80A and 80B, but the planetary gear 80A does not perform revolution, and only the second stage planetary gear 80B which has a larger reduction ratio performs revolution in the inner gear 81B. The rotation of the rear gear carrier 85 which rotates due to the revolution of the planetary gear 80B is transmitted to the front gear carrier 130 via the inner gear 81C from the third stage planetary gear 80C. Accordingly, the reduction of the third stage is cancelled, and the rotation of the front gear carrier 130 is transmitted to the main shaft 165 at a speed larger than that of 2nd gear.

[0141] Figure 22 The 4th gear is shown. The speed switching dial 9 is rotated 90° to the right in plan view from 3rd gear. At this rotational position of the speed switching dial 9, the flat gear ring 120 is rotated by 18° so that the speed switching plate 110 is formed in the same rearward inclined posture as that of 2nd gear. Accordingly, the rotation of the first stage inner gear 81A is restricted, and the second stage inner gear 81B freely rotates.

[0142] At this time, the speed switching gear 151 is rotated 90° to the left from 3rd gear in plan view, as shown in Fig. 12C, to a fourth rotational position in which the eccentric pin 152 is located in front of the left side. Accordingly, the speed switching holder 153 and the inner gear 81C are still in the advanced position. Figure 22

[0143] Accordingly, the rotation input from the input gear 74 is transmitted to the planetary gears 80A and 80B, but the planetary gear 80B does not perform revolution, and only the first stage planetary gear 80A which has a smaller reduction ratio performs revolution in the inner gear 81A. The rotation of the rear gear carrier 85 which rotates due to the revolution of the planetary gear 80A is transmitted to the front gear carrier 130 via the inner gear 81C from the third stage planetary gear 80C. Accordingly, the rotation of the front gear carrier 130 is transmitted to the main shaft 165 at a speed larger than that of 3rd gear.

[0144] Thus, the speed stage of the reduction portion 75 can be selected by the rotational operation of the speed switching dial 9. However, in a specific operation mode, the speed stage of the reduction portion 75 is automatically switched to a specific speed stage by the linked operation of the linked switching portion 78 which is accompanied by the rotation of the mode switching ring 6. Hereinafter, the linked operation will be described supplementarily.​

[0145] (2) Explanation of the striking portion

[0146] As shown in Figure 10 , Figure 11 , Figure 23 , the striking portion 76 includes a main shaft 165, an inner hammer 166, an outer hammer 167, a hammer sleeve 168, an outer coil spring 169, an inner coil spring 170, and the anvil 8.

[0147] The striking portion 76 is housed in the front-side gear housing 61 except for the front portion of the anvil 8. The anvil 8 penetrates the front plate portion 63 of the front-side gear housing 61. A bearing 171 that supports the anvil 8 is held in the front plate portion 63. A pair of arm portions 172, 172 that protrude in the radial direction are provided in the rear end of the anvil 8 in the front-side gear housing 61.

[0148] The rear portion of the main shaft 165 is supported by the bracket plate 136 and extends forward. A small-diameter portion 173 is formed in the front end of the main shaft 165. A bottomed hole 174 into which the small-diameter portion 173 is fitted is formed in the rear end axis of the anvil 8. In the forward position of the anvil 8 at which the arm portions 172 abut against the front plate portion 63, a gap is formed between the front surface of the main shaft 165 other than the small-diameter portion 173 and the rear surface of the anvil 8. Accordingly, the anvil 8 can move rearward in accordance with the gap.

[0149] A through hole 175 is formed in the axis of the main shaft 165 throughout the entire length. A ball 176 is housed in the front portion of the through hole 175. A reduced-diameter portion 177 in which the opening diameter is reduced is formed in the rear of the ball 176 and in the through hole 175. A coil spring 178 is provided between the ball 176 and the reduced-diameter portion 177, thereby pressing the ball 176 against the inner surface of the bottomed hole 174. Accordingly, the anvil 8 is forced to the forward position in the normal state.

[0150] A flange 179 is formed in the front of the bracket plate 136 and in the rear portion of the main shaft 165. A pair of inner cam grooves 180, 180 are formed in the rear of the small-diameter portion 173 and in the front portion of the main shaft 165. The inner cam grooves 180 are formed in a V shape with the tip end facing forward.

[0151] The inner hammer 166 is cylindrical and is fitted to the front portion of the main shaft 165. A pair of claws 181, 181 protruding forward is formed on the front surface of the inner hammer 166. The claws 181, 181 are engaged with the arm portions 172, 172 of the anvil 8 in the rotational direction. A pair of outer cam grooves 182, 182 extending from the front end to the rear is provided on the inner peripheral surface of the inner hammer 166. Cam rollers 183, 183 are fitted between the outer cam grooves 182, 182 and the inner cam groove 180 of the main shaft 165. Accordingly, the inner hammer 166 is coupled to the main shaft 165 by the cam rollers 183, 183. Here, the inner hammer 166 is relatively movable with respect to the main shaft 165 in the front-rear direction and the rotational direction within a range in which the cam rollers 183 are rotatable between the inner cam groove 180 and the outer cam grooves 182.

[0152] A ring-shaped groove portion 184 is formed on the rear surface of the inner hammer 166. A plurality of (six) inner fitting grooves 185, 185, … are formed on the peripheral surface of the inner hammer 166 near the rear end. The inner fitting grooves 185 are formed at equal intervals in the circumferential direction of the inner hammer 166 and extend in the front-rear direction.

[0153] The outer hammer 167 is a bottomed cylinder open at the front and is fitted to the rear portion of the main shaft 165. The outer hammer 167 includes a bottom plate portion 190, an inner cylinder portion 191, and an outer cylinder portion 192. The center of the bottom plate portion 190 is penetrated by the main shaft 165. The inner cylinder portion 191 protrudes forward from the inner periphery of the bottom plate portion 190. The outer cylinder portion 192 protrudes forward from the outer periphery of the bottom plate portion 190. The outer cylinder portion 192 is formed longer than the inner cylinder portion 191 and extends further forward.

[0154] A ring-shaped inner groove 193 is formed on the inner surface of the outer periphery of the bottom plate portion 190. As shown in FIG. 11B, the inner groove 193 receives a plurality of rollers 194, 194, … over the entire circumference. The rollers 194 receive the rear end of the outer coil spring 169 with a washer 195 interposed therebetween. The rear end of the inner coil spring 170 abuts the inner surface of the bottom plate portion 190 on the inner side of the rollers 194. Figure 18 B, the inner groove 193 receives a plurality of rollers 194, 194, … over the entire circumference. The rollers 194 receive the rear end of the outer coil spring 169 with a washer 195 interposed therebetween. The rear end of the inner coil spring 170 abuts the inner surface of the bottom plate portion 190 on the inner side of the rollers 194.

[0155] A ring-shaped protrusion 196 is formed on the rear surface of the bottom plate portion 190 in contact with the rear of the inner groove 193. The protrusion 196 protrudes into the avoidance recess 141 of the front surface of the bracket plate 136. Accordingly, the bracket plate 136 and the bottom plate portion 190 overlap in the radial direction, making the axial direction compact.

[0156] An annular inner recess 197 is formed in the inner peripheral surface of the inner cylinder portion 191 from the rear end toward the front. The inner recess 197 opposes the flange 179 of the main shaft 165 from the front. A necked portion 198 is formed on the front side of the flange 179 and on the outer periphery of the main shaft 165. A plurality of balls 199, 199,... are fitted in the necked portion 198 over the entire circumference. The balls 199 abut against the front end inner surface of the inner recess 197 and receive the inner cylinder portion 191 in the axial direction. A clasp 200 is engaged in the inner cylinder portion 191 on the front side of the main shaft 165. Accordingly, the outer hammer 167 is coupled to the main shaft 165 in a manner that the inner cylinder portion 191 is restricted from moving forward and backward between the balls 199 and the clasp 200 and is relatively rotatable.

[0157] A plurality of (six) holding slits 201, 201,... are formed in the outer cylinder portion 192. As shown in Figure 18 C, the holding slits 201 are arranged at equal intervals in the circumferential direction of the outer cylinder portion 192 and extend in the front-rear direction. Each holding slit 201 is located radially outward of the inner fitting groove 185 of the inner hammer 166. However, the holding slit 201 is formed longer in the front-rear direction than the inner fitting groove 185. Figure 24 B, a plurality of concave portions 202, 202,... of a semispherical shape are formed in the circumferential direction of the outer cylinder portion 192 and between the holding slits 201, 201,.... A ball 203 is fitted in each concave portion 202. Figure 10 Figure 11 Figure 24 As shown in

[0158] The hammer sleeve 168 is a sleeve member that is fitted over the outer hammer 167. A plurality of (six) outer fitting grooves 210, 210,... are formed in the inner peripheral surface of the hammer sleeve 168. Each outer fitting groove 210 is arranged at equal intervals in the circumferential direction of the hammer sleeve 168 and is formed over the entire length of the hammer sleeve 168. However, each outer fitting groove 210 is formed so that the depth in the radial direction is shallower in a rear groove portion 211 as shown in Figure 18 C, deeper in a middle groove portion 212 as shown in Figure 24 A and 24B, and deepest in a front groove portion 213 as shown in Figure 24 ​​The order of the front groove portion 213, which is deeper than the middle groove portion 212, shown in C, is stepped deeper as it tends toward the front. The outer fitting groove 210 is located radially outward of the holding slit 201 of the outer hammer 167. Between the outer fitting grooves 210, 210,..., in the circumferential direction, a plurality of coupling grooves 214, 214,..., which are shorter in the front-rear direction than the outer fitting groove 210, are formed toward the rear from the front end of the hammer sleeve 168. In each of the coupling grooves 214, a ball 203 that has been fitted to the recessed portion 202 of the outer hammer 167 is fitted. Accordingly, the outer hammer 167 and the hammer sleeve 168 are integrated in the rotational direction. However, the hammer sleeve 168 is able to move forward and backward with a stroke in which the ball 203 moves relatively within the coupling groove 214. A ring groove 215 is formed in the rear portion of the outer periphery of the hammer sleeve 168.

[0159] In each of the inner fitting grooves 185 of the inner hammer 166, the holding slit 201 and the support groove 204 of the outer hammer 167, and the outer fitting groove 210 of the hammer sleeve 168, which overlap in the radial direction, a plurality of (five) coupling balls 216, 216,... are fitted in a manner spanning each groove and slit. In order to maintain this fitted state, a plurality of U-shaped clamps 220, 220,... are respectively caught in the holding slit 201, 201,... on the front side of the five coupling balls 216. Each of the clamps 220 is inserted from the rear into the front end of the holding slit 201 in a posture in which both ends face forward and the short side direction is along the radial direction of the outer cylinder portion 192 of the outer hammer 167. As shown in Figure 24 C, the inner end portion 221 of each of the clamps 220 on the radial inner side is caught in the support groove 204 of the outer cylinder portion 192. The outer end portion 222 of each of the clamps 220 on the radial outer side is caught in the outer fitting groove 210 of the hammer sleeve 168.

[0160] Accordingly, the inner hammer 166 and the outer hammer 167 are connected in the front-rear direction by the coupling balls 216 in a state in which the front portion of the outer cylinder portion 192 is externally fitted to the inner hammer 166. However, in the rotational direction, the structure is switched between an integrated structure and a separate structure in accordance with the front-rear position of the hammer sleeve 168.

[0161] The outer disc spring 169 and the inner disc spring 170 are externally fitted to the main shaft 165 in double between the inner hammer 166 and the outer hammer 167. The front end of the outer disc spring 169 abuts against the rear surface of the inner hammer 166 on the outer side of the groove portion 184.

[0162] The inner disc spring 170 is formed by counter-winding a wire having a larger diameter than the outer disc spring 169 with respect to the outer disc spring 169. The front end of the inner disc spring 170 is inserted into the groove portion 184 of the inner hammer 166. In the inner surface of the front side of the groove portion 184, a washer 223 and a plurality of balls 224, 224,... that receive the front end of the inner disc spring 170 are housed. Figure 24 B).

[0163] The inner hammer 166 is forced to the advanced position of the outer disc spring 169 and the inner disc spring 170 so that the cam ball 183 is positioned at the tip of the inner cam groove 180 of the spindle 165 and at the rear end of the outer cam groove 182 of the inner hammer 166. Figure 10 and Figure 11 The outer hammer 167 is forced to the advanced position of the outer disc spring 169 and the inner disc spring 170 so that the cam ball 183 is positioned at the tip of the inner cam groove 180 of the spindle 165 and at the rear end of the outer cam groove 182 of the inner hammer 166.

[0164] The inner periphery of the bottomed hole 174 of the anvil 8, the inner periphery of the inner hammer 166, and the inner periphery of the inner cylindrical portion 191 of the outer hammer 167 are respectively provided with lubricating grease grooves 225, 225,.... Each of the lubricating grease grooves 225 is annular throughout the entire circumference of the respective inner periphery.

[0165] In particular, the lubricating grease grooves 225 of the inner periphery of the bottomed hole 174 of the anvil 8 and the inner periphery of the inner hammer 166 are provided with two each at a prescribed interval in the front-rear direction. The provision of a plurality of the lubricating grease grooves 225 on the inner periphery allows the lubricating grease to be dispersed between the respective inner periphery and the shaft inside thereof, thereby maintaining lubrication.

[0166] A communication hole 226 that communicates with the through hole 175 is formed in the intermediate portion of the spindle 165 and in the rear of the inner cam groove 180 in the diametrical direction. The communication hole 226 communicates with one of the lubricating grease grooves 225 of the inner hammer 166 in the advanced position.

[0167] With respect to the striking portion 76, the hammer sleeve 168 is moved forward and rearward by the rotational operation of the mode conversion ring 6, thereby switching between a state in which the striking work is possible and a state in which the striking work is impossible.

[0168] In the retracted position of the hammer sleeve 168, as shown in Figure 22 E, the deepest front groove portion 213 of the outer fitting groove 210 is positioned outside the holding slit 201 of the outer hammer 167. Therefore, when the centrifugal force acts, the five coupling balls 216 are fitted in the front groove portion 213, the holding slit 201, and the support groove 204, and are disengaged from the inner fitting groove 185 of the inner hammer 166. Accordingly, only the inner hammer 166 generates the striking action.

[0169] In the intermediate position of the hammer sleeve 168 after being advanced from the retracted position, as shown in Figure 21 E, the middle groove portion 212 of the outer fitting groove 210 is positioned outside the holding slit 201. Therefore, with respect to the five coupling balls 216, when the centrifugal force acts, the three coupling balls 216 on the outside are fitted in the middle groove portion 212 and the holding slit 201. The two coupling balls 216 on the inside are fitted in the support groove 204 of the holding slit 201 and the inner fitting groove 185. Accordingly, the inner hammer 166, the outer hammer 167, and the hammer sleeve 168 are integrated to generate the striking action.

[0170] In the advanced position of the hammer sleeve 168 after being advanced from the intermediate position, as shown inFigure 19 E and Figure 20 E, the rear groove portion 211 and the middle groove portion 212 of the outer fitting groove 210 are located outside the holding slit 201. Therefore, even if the centrifugal force acts, the movement of the five coupling balls 216 is restricted. Accordingly, the inner hammer 166 cannot retreat, and the striking action is not generated.

[0171] (3) Description of the Vibration Section

[0172] The vibration section 77 is provided between the front plate portion 63 of the front side gear case 61 and the hammer case 7. As shown in Figure 10 Figure 11 Figure 25 The vibration section 77 includes the anvil 8, a front side cam 230, a rear side cam 231, a restriction ring 232, a disc spring 233, and a vibration switching plate 234.

[0173] The front side cam 230 is annular and is fixed to the anvil 8 at the front portion in the hammer case 7. A front side cam surface 235, which is concave-convex and continuous in the circumferential direction, is formed on the rear surface of the front side cam 230. The front side cam 230 is supported by a bearing 236 to the hammer case 7. A spring ring 237 is fixed to the front side of the front side cam 230 and is engaged with the anvil 8.

[0174] The rear side cam 231 is fitted to the anvil 8 at the rear of the front side cam 230. As shown in Figure 26 A, the rear side cam 231 is annular and has a larger diameter than the front side cam 230. A rear side cam surface 238, which is concave-convex and continuous in the circumferential direction, is formed on the front surface of the rear side cam 231. As shown in Figure 26 B, three cam claws 239, 239,... are formed on the rear surface of the rear side cam 231 at equal intervals in the circumferential direction. A plurality of balls 240, 240,... are arranged in the circumferential direction at the rear of the rear side cam 231 and inside the cam claws 239. As shown in Figure 26 C, a receiving washer 241 is arranged at the rear of the balls 240 and at the front side of the front plate portion 63, thereby supporting the balls 240. Three engagement protrusions 242, 242,... protrude to the radial outside at the outer periphery of the receiving washer 241. A locking rib 243 is protrudingly provided on the front surface of the front plate portion 63. The locking rib 243 engages with the engagement protrusions 242 in the rotational direction, thereby restricting the rotation of the receiving washer 241.

[0175] The restriction ring 232 is arranged so as to have a larger diameter than the receiving washer 241 and be movable forward and rearward at the front of the front plate portion 63. A guide rib 245, which is annular and has a smaller diameter than the restriction ring 232, is protrudingly provided on the rear surface of the hammer case 7. Three restriction pins 246, 246,... are provided on the rear surface of the hammer case 7 at the outside of the guide rib 245 and protrude to the rear. The restriction pins 246 are arranged at equal intervals in the circumferential direction and protrude to the rear, as shown in​​Figure 12 As shown in Figure A, the rear end is inserted into the receiving hole 63a provided in the front plate portion 63. Cutout recesses 247 are formed on the inner side of each limiting pin 246 and on the guide rib 245.

[0176] Three engaging recesses 248, 248... are formed on the outer periphery of the limiting ring 232 for engaging with each limiting pin 246. This allows the limiting ring 232 to move back and forth along the limiting pin 246 while its rotation is restricted by the limiting pin 246. Three limiting protrusions 249, 249... are formed on the inner side of each engaging recess 248 and on the inner periphery of the limiting ring 232, protruding towards the center. Each limiting protrusion 249 protrudes into the inner side of the guide rib 245 via a notch 247. In the forward position of the limiting ring 232, each limiting protrusion 249 engages with each cam pawl 239 provided on the rear cam 231 in the rotational direction. This restricts the rotation of the rear cam 231. In the retracted position of the limiting ring 232, each limiting protrusion 249 separates from the rear of each cam pawl 239. This allows the rear cam 231 to rotate freely.

[0177] A washer 250 is provided on the rear side of the limiting ring 232. The diameter of the washer 250 is the same as that of the limiting ring 232, and it has through holes 251, 251... for each limiting pin 246 to pass through.

[0178] like Figure 12 As shown in Figure A, each disc spring 233 is disposed within the receiving hole 63a of the front plate portion 63, between the washer 250 and the bottom of the receiving hole 63a. Each disc spring 233 is externally mounted to the rear end of each limiting pin 246 that has penetrated through the washer 250. Accordingly, each disc spring 233 applies a forward force to the washer 250 and the limiting ring 232.

[0179] Three vibration switching plates 234 are arranged at equal intervals along the circumferential direction on the outer side of the limiting ring 232, at a different phase from that of the limiting pin 246. Each vibration switching plate 234 is a thin plate extending in the front-rear direction. A front folded portion 252 is formed on the front part of each vibration switching plate 234, which bends inward and locks into the front surface of the limiting ring 232. A rear folded portion 253 is formed on the rear part of each vibration switching plate 234, which bends outward. The outer ends of each rear folded portion 253 are formed into tapered portions 254 that bend backward and outward at both ends in the width direction.

[0180] Three retaining grooves 255, 255... are formed on the outer peripheral surface of the front plate portion 63 of the front gear housing 61. Each retaining groove 255 opens radially outward and forward. The vibration switching plate 234 engages with each retaining groove 255. However, each tapered portion 254 protrudes radially outward from the retaining groove 255.

[0181] Three support ribs 256, 256, … are provided on the inner peripheral surface of the hammer housing 7 in a manner protruding toward the inside. Each support rib 256 is inserted into each holding groove 255 from the front, thereby supporting the vibration switching plate 234 between the inner surface of the holding groove 255. Accordingly, each vibration switching plate 234 is movable back and forth between the holding groove 255 and the support rib 256. However, each vibration switching plate 234 is forced toward the front together with the restriction ring 232, which is caught by the front bending portion 252.

[0182] With respect to the vibration portion 77, the forward movement restriction of each vibration switching plate 234 and the release of the restriction are switched by the rotation operation of the mode conversion ring 6, thereby enabling selection of the presence or absence of vibration. That is, when the forward movement restriction of the vibration switching plate 234 is released, as described above, the restriction ring 232 advances, and the restriction protrusion 249 is engaged with the cam claw 239 of the rear-side cam 231. Accordingly, the rotation of the rear-side cam 231 is restricted. In this case, when the anvil 8 rotates, the front-side cam face 235 of the front-side cam 230 is engaged with the rear-side cam face 238 of the rear-side cam 231 in the rotation direction. Therefore, the anvil 8 is minutely moved in the front-back direction in accordance with the clearance with respect to the main shaft 165, thereby generating vibration.

[0183] When the forward movement of the vibration switching plate 234 is restricted, as described above, the restriction ring 232 retreats, and the restriction protrusion 249 is separated rearward from the cam claw 239. Accordingly, the rotation restriction of the rear-side cam 231 is released. In this case, even if the anvil 8 rotates, the front-side cam 230 is not engaged with the rear-side cam 231, and therefore, the anvil 8 does not generate vibration.

[0184] Here, the front-side cam 230 is directly supported by the bearing 236, and the movement of the rear-side cam 231 toward the front is restricted by the bearing 236. Accordingly, the number of components is reduced, and the compactness in the axial direction is achieved.

[0185] (4) Explanation of Linkage Switching Portion

[0186] As Figure 10 and Figure 23As shown, a rib 260 is formed circumferentially on the inner circumference of the mode switching ring 6 and on the outer side of the vibration switching plate 234. The rear bend 253 of the vibration switching plate 234, which is subjected to forward force, engages with the rib 260 from the rear. Three sharp, conical cutouts 261, 261... are formed at equal intervals circumferentially on the rib 260. The conical portion 254 of the rear bend 253 can engage with each cutout 261. Accordingly, at the rotational position of the mode switching ring 6 where each cutout 261 is in front of each conical portion 254, the limiting ring 232 and the vibration switching plate 234 are advanced to a forward position by the force applied by the coil spring 233. Accordingly, as described above, the limiting ring 232 limits the rotation of the rear cam 231. When the mode switching ring 6 is rotated, the conical cut-off portions 261 press the conical portions 254 backward, causing the vibration switching plate 234 and the limiting ring 232 to retract to a rearward position. As a result, the limiting ring 232 separates from the rear cam 231 to the rear, allowing the rear cam 231 to rotate freely.

[0187] like Figure 23 and Figure 27 As shown, a guide plate 265 is integrally formed at the rear end of the mode conversion ring 6. The guide plate 265 is formed in an arc shape along the circumference of the mode conversion ring 6 and extends rearward. A curved guide slit 266 is formed on the guide plate 265. The end of the guide slit 266 in the left-turning direction in the main view has a first slit 267 extending in the right-turning direction of the guide plate 265. A second slit 268 is continuously formed on the first slit 267 and tilts forward as it approaches the right-turning direction from the end of the first slit 267. A third slit 269 is continuously formed on the second slit 268 and extends in the right-turning direction from the end of the second slit 268. A fourth slit 270 is continuously formed on the third slit 269 and tilts forward as it approaches the right-turning direction from the end of the third slit 269. A fifth slit 271 is continuously formed on the fourth slit 270 and extends in the right-turning direction from the end of the fourth slit 270.

[0188] A plurality of protrusions 272, 272... are formed circumferentially on the inner side of the guide plate 265 and on the rear surface of the protrusion 260 of the mode conversion ring 6. The protrusions 272 are arranged at predetermined intervals circumferentially. Furthermore... Figure 12 As shown in Figure C, a leaf spring 273 is located behind the protrusion 272 and on the lower surface of the front gear housing 61, elastically engaging with the protrusions 272 and 272. The engaging position of the leaf spring 273 serves as the switching position for each operating mode.

[0189] A thick wall portion 274 is formed on the outer surface of the guide plate 265 at a position other than the guide slit 266. The outer surface of the thick wall portion 274 protrudes further to the radially outer side than the guide slit 266. The thick wall portion 274 has a triangular first hill portion 275 protruding to the rear at the front side of the second slit 268 and the third slit 269. The thick wall portion 274 has a second hill portion 276 having a hypotenuse that moves to the rear as it approaches the right turning direction side from the front side of the fourth slit 270 and the fifth slit 271. The hypotenuse of the second hill portion 276 passes the end of the fifth slit 271 and extends to the rear. A rear flat portion 277 and a front flat portion 278 that are shorter in the circumferential direction are formed on the hypotenuse of the second hill portion 276. The front flat portion 278 is located forward of the fifth slit 271.

[0190] A mode conversion lever 280 provided on the lower side of the front side gear housing 61 engages with the guide slit 266. The mode conversion lever 280 has a straight portion 281 extending in the front-rear direction at the front portion. The straight portion 281 passes through a support frame 282 provided on the lower surface of the front side gear housing 60, thereby being supported by a rod holder 310 described later. The mode conversion lever 280 has a square frame portion 283 extending in the up-down direction at the rear end of the straight portion 281. An upwardly directed guide protrusion 284 is formed on the upper surface of the rear end of the straight portion 281. The guide protrusion 284 engages with the guide slit 266 from the outer side, thereby being able to move relatively within the guide slit 266.

[0191] A mode conversion fork 285 provided on the lower side of the front side gear housing 61 passes through the square frame portion 283 of the mode conversion lever 280. The mode conversion fork 285 has a pair of link portions 286, 286 on the left and right sides, and a link portion 287 that links between the link portions 286, 286. The link portion 287 passes through the square frame portion 283 of the mode conversion lever 280 in the left-right direction. The link portions 286, 286 extend upwardly and to the left and right outer sides from the left and right ends of the link portion 287. Long circular holes 288 extending in the elongated direction of the link portions 286 are formed in the intermediate portions of the respective link portions 286. Also as shown in FIG. 28, a pair of support shafts 289, 289 are formed outwardly on the lower half side of the front side gear housing 61 and on the left and right circumferential surfaces. The support shafts 289, 289 are loosely inserted into the long circular holes 288, 288. Figure 18 C, a pair of support shafts 289, 289 are formed outwardly on the lower half side of the front side gear housing 61 and on the left and right circumferential surfaces. The support shafts 289, 289 are loosely inserted into the long circular holes 288, 288.

[0192] A pair of locking pins 290, 290 are inserted from the radially outer side of the front side gear housing 61 at the upper ends of the link portions 286, 286. A pair of guide holes 291, 291 extending in the front-rear direction are formed on the left and right side surfaces of the front side gear housing 61. The locking pins 290, 290 pass through the guide holes 291, 291 and engage with the ring groove 215 of the hammer sleeve 168 inside the front side gear housing 61.

[0193] Accordingly, when the mode switching ring 6 is rotated, the mode switching rod 280, which engages with the guide protrusion 284 and the guide slit 266, is guided by the guide slit 266 and moves back and forth. Consequently, the connecting portion 287 of the mode switching fork 285 moves back and forth, and therefore, the left and right connecting rod portions 286, 286 swing back and forth around the support shafts 289, 289. Consequently, the hammer sleeve 168, which is engaged by the upper locking pins 290, 290, moves linearly in the back-and-forth direction.

[0194] Here, the connecting rod 286 and the support shaft 289 are joined via the elongated hole 288. Therefore, even if the lower end of the connecting rod 286 swings back and forth, the support shaft 289 can move relative to it within the elongated hole 288, allowing the locking pin 290 to move linearly along the guide hole 291 in the front-back direction. This ensures that the hammer sleeve 168 always moves smoothly in a straight line without tilting due to the locking pins 290, 290 located on the left and right outer sides of the shaft. Furthermore, due to the clearance between the elongated hole 288 and the support shaft 289, even if the mode switching fork 285 is made of a relatively hard material, assembly can be performed without difficulty.

[0195] A linkage winding portion 295 is provided on the inner side of the guide plate 265. The linkage winding portion 295 is an arc-shaped plate body fixed to the guide plate 265 in an overlapping state from the inside. A guide window 296 is formed in the linkage winding portion 295 along the circumferential direction. A curved guide end 297 is formed at the rear end of the guide window 296. The guide end 297 has a first end 298 extending circumferentially along the linkage winding portion 295 at its end in the same left-turning direction as the guide plate 265. A second end 299 is continuously formed on the first end 298, which is inclined forward as it moves towards the right-turning direction from the end of the first end 298. A third end 300 is continuously formed on the second end 299, extending circumferentially from the end of the second end 299.

[0196] The linkage rod 301 is engaged with the linkage winding part 295. The linkage rod 301 is a strip groove 303 provided on the lower surface of the front gear housing 61 in the front-rear direction. Figure 18 C Figure 23 The plate extends along the front-to-back direction. A latching pin 302 is provided at the front end, which engages with the guide end 297 of the linkage winding section 295 from the front. The rear part of the linkage rod 301 is positioned on the upper side of the speed switching retainer 153. The rear part of the linkage rod 301 bends downward between retaining plates 159. The rear part of the linkage rod 301 passes through the connecting plates 160 between the connecting plates 160 on the front side of the protrusion 148 of the speed switching wire 145. The lower end of the linkage rod 301 is formed into an inverted T-shape on the lower side of the speed switching retainer 153 to prevent detachment.

[0197] Accordingly, the link lever 301 is able to move forward and backward in a state where the hook pin 302 is hooked to the first end portion 298 of the guide end portion 297. When the link winding portion 295 rotates leftward together with the mode conversion ring 6 in the main view, the link lever 301 slides forward due to the inclination of the second end portion 299. The movement of the link lever 301 backward in a state where the hook pin 302 is hooked to the third end portion 300 is restricted.

[0198] A link cam 305 is provided on the rear upper side of the speed switch holder 153. As shown in Figs. 8 and 9, the link cam 305 is a slender plate body having a left and right width that narrows as it approaches the front, and having inclined surfaces on the left and right sides. A cut groove 306 is formed from the rear end toward the front in the left and right directions on the rear portion of the link cam 305. The eccentric pin 152 of the speed switch gear 151 penetrates the cut groove 306 from above. A guide recess 307 is formed in the left and right directions on the lower surface of the link cam 305. The guide protrusion 157 provided on the upper surface of the speed switch holder 153 engages with the guide recess 307. Accordingly, the link cam 305 moves forward and backward integrally with the speed switch holder 153. In addition, the link cam 305 slides left and right on the speed switch holder 153 in correspondence with the movement in the left and right directions of the eccentric movement of the eccentric pin 152. Figure 12 B and Figure 14 As shown in Figs. 8 and 9, the link cam 305 is a slender plate body having a left and right width that narrows as it approaches the front, and having inclined surfaces on the left and right sides. A cut groove 306 is formed from the rear end toward the front in the left and right directions on the rear portion of the link cam 305. The eccentric pin 152 of the speed switch gear 151 penetrates the cut groove 306 from above. A guide recess 307 is formed in the left and right directions on the lower surface of the link cam 305. The guide protrusion 157 provided on the upper surface of the speed switch holder 153 engages with the guide recess 307. Accordingly, the link cam 305 moves forward and backward integrally with the speed switch holder 153. In addition, the link cam 305 slides left and right on the speed switch holder 153 in correspondence with the movement in the left and right directions of the eccentric movement of the eccentric pin 152.

[0199] On the left and right sides of the holding plates 159, 159 of the speed switch holder 153, two parallel left and right bars 308, 309 are penetrated front and back. The rear ends of the left and right bars 308, 309 that have penetrated the holding plates 159, 159 oppose the left and right inclined surfaces of the link cam 305, respectively. The front and back length of the right bar 309 is shorter than that of the left bar 308. The front portions of the left and right bars 308, 309 penetrate the left and right of a bar holder 310. The bar holder 310 is supported within the support frame 282 of the front side gear case 61, and has the straight portion 281 of the mode conversion lever 280 penetrating therethrough. The link lever 301 is supported on the upper surface of the bar holder 310.

[0200] Accordingly, the left and right bars 308, 309 are supported in parallel by the holding plates 159, 159 and the bar holder 310, and are able to slide forward and backward, respectively. A spring ring 311 for preventing detachment and a disc spring 312 for buffering are provided on the rear side of the bar holder 310 and on the left and right bars 308, 309. The front ends of the left and right bars 308, 309 that have penetrated the bar holder 310 oppose the rear surface of the thick wall portion 274 provided on the guide plate 265 of the mode conversion ring 6.

[0201] With regard to the link switch portion 78, the forward and backward positions of the hammer sleeve 168 are switched by the mode conversion fork 285 in correspondence with the rotational operation of the mode conversion ring 6.

[0202] Furthermore, with the rotation of the mode switching ring 6, the linkage lever 301 switches between a state that allows the speed switching retainer 153 to move forward and backward and a state that restricts the speed switching retainer 153 to move backward while keeping it in the forward position.

[0203] Furthermore, with the rotation of the mode switching ring 6, the state is switched to a state in which the forward and backward movement of the left and right bars 308 and 309 is unrestricted between the linkage cam 305 and the thick-walled portion 274, which together with the speed switching retainer 153 are allowed to move forward and backward, and a state in which the forward and backward movement of the left and right bars 308 and 309 is restricted by the linkage cam 305 and the thick-walled portion 274, which together with the speed switching retainer 153 are always in the forward position.

[0204] These combinations allow for the mechanical selection of four motion modes. Each motion mode is further explained in detail below.

[0205] (5) Description of the cutter head assembly structure

[0206] For example Figure 28 and Figure 29 As shown, a blade insertion hole 315 with an open front end is formed at the axis of the anvil 8. The cross-section of the blade insertion hole 315 is a regular hexagon. A blade sleeve 316 is externally mounted to the front end of the anvil 8 in a manner that allows it to move back and forth. A pair of ball bearing storage portions 317, 317 are provided inside the blade sleeve 316 and on the anvil 8. The ball bearing storage portions 317 are elongated oval shapes extending in the front-back direction and are located at a point symmetrical about the blade insertion hole 315. The ball bearing storage portions 317 have a tapered shape whose cross-section decreases from the radially outer side to the radially inner side. A pair of balls 318, 318 are stored in the ball bearing storage portions 317, 317. The balls 318 are stored in the ball bearing storage portions 317 in a manner that allows them to move in both the radial and front-back directions. The diameter of the ball bearing 318 is larger than the radially inner opening of the ball bearing receiving portion 317, allowing it to protrude from the opening into the cutter insertion hole 315 at its radially inner position. Furthermore... Figure 25 As shown, an annular groove 319 is formed at the rear of the ball bearing receiving part 317 and in the anvil seat 8. Two O-rings 320, 320 are externally mounted in the groove 319.

[0207] An annular stopper 321 is formed on the inner periphery of the tool head sleeve 316. When the stopper 321 is located on the outer side of the balls 318, 318, the balls 318, 318 are restricted to a protruding position protruding from the openings of the ball accommodating portions 317, 317. On the front side of the stopper 321 and on the outer side of the anvil 8, a conical spring 322 whose diameter increases toward the rear is fitted. The front end of the conical spring 322 abuts against a flat washer 324 located on the front end of the anvil 8 by means of an annular spring 323. The rear end of the conical spring 322 abuts against the stopper 321. Accordingly, the tool head sleeve 316 is urged rearward by the conical spring 322. The clasp 237 of the anvil 8 is located on the rear side of the tool head sleeve 316. Accordingly, as shown in FIG. 17, the tool head sleeve 316 is urged to a retracted position where the stopper 321 abuts against the clasp 237. In this retracted position, the stopper 321 is located on the outer side of the balls 318, 318. Figure 10

[0208] In the state where the tool head sleeve 316 is located in the retracted position, the tool head B is inserted into the tool head insertion hole 315. Then, as shown in FIG. 18A, the balls 318, 318 abutting against the tool head B move in the ball accommodating portions 317, 317 rearward of the stopper 321 against the urging of the O-ring 320. Then, the balls 318, 318 retreat toward the rear of the ball accommodating portions 317, 317. Accordingly, even if the tool head sleeve 316 is not slid forward, the tool head B can be directly inserted into the tool head insertion hole 315. At this time, the ball accommodating portions 317, 317 become conical in shape expanding from the radially inner side to the radially outer side, and thus the balls 318, 318 abutting against the tool head B abut against the rear of the ball accommodating portions 317, 317 in the direction of moving away from the tool head insertion hole 315 along the conical shape. Accordingly, the load at the time of tool head insertion is reduced. Figure 29

[0209] When the tool head insertion is completed, as shown in FIG. 18B, the balls 318, 318 move in the ball accommodating portions 317, 317 inward of the stopper 321 by the urging of the O-ring 320. Accordingly, the balls 318, 318 return to the protruding position protruding from the ball accommodating portions 317, 317 and are caught to the tool head B, thereby preventing the tool head B from falling off. Figure 29

[0210] On the other hand, as shown in FIG. 18C, if the tool head sleeve 316 is slid forward against the urging of the conical spring 322, the restriction of the movement of the balls 318, 318 by the stopper 321 is released. Accordingly, the tool head B can be pulled out of the tool head insertion hole 315. If the tool head B is pulled out, the balls 318, 318 return to the protruding position protruding from the ball accommodating portions 317, 317 by the urging of the O-ring 320, thereby becoming the state of FIG. 18B. Figure 29 Figure 29

[0211] ​​​​​Here, a conical spring 322 is adopted for the application of force to the bit sleeve 316, so even if the free length of the conical spring 322 is increased, it is difficult to flex. Accordingly, this becomes a countermeasure against poor disassembly of the bit B. In addition, the force can be increased. Accordingly, it is difficult for the bit B to fall off due to vibration.

[0212] (Explanation of each operation mode)

[0213] Next, the switching and operation of each operation mode based on the linkage switching section 78 will be described. Note that stop ribs 327, 327 are provided protruding to the left and right at the front of the front-side gear housing 61 and at the front of the linkage lever 300. Figure 9 A、 Figure 13 、 Figure 23 ). The stop ribs 327, 327 limit the left and right rotational positions of the guide plate 265 accompanying the rotational operation of the mode conversion ring 6.

[0214] (1) Drilling mode

[0215] As shown in FIG. 24A, the mode conversion ring 6 is turned to the right to the limit position in the front view and formed in the drilling mode. Figure 19

[0216] In the drilling mode, the guide plate 265 is also located in the right- turned position, and the first and second mountain-shaped portions 275, 276 of the thick-walled portion 274 avoid the front of the left and right rods 308, 309 (B, C). Figure 19

[0217] Accordingly, the mode conversion lever 280 is in the retracted position such that the guide protrusion 284 is located in the first slit 267 of the guide slit 266. Then, the connecting portion 287 of the mode conversion fork 285 is in the retracted position, so the left and right link portions 286, 286 swing about the fulcrums 289, 289 and cause the upper end retaining pins 290, 290 to slide toward the front end of the guide holes 291, 291.

[0218] Accordingly, the hammer sleeve 168 is in the advanced position, so as described above, the rear groove portion 211 and the middle groove portion 212 of the outer fitting groove 210 are located outside the holding slit 201. Therefore, even if the centrifugal force acts, the movement of the five coupling balls 216 is restricted, and the retraction of the inner hammer 166 is restricted (D, E). Figure 19 The catch pin 302 of the linkage lever 301 is caught in the first end portion 298 of the guide end portion 297 of the linkage winding portion 295, so movement in the forward direction is permitted. Accordingly, the speed switching holder 153 can move forward and backward, so rotation of the speed switching gear 151 is also permitted, and thus, selection of 1st-4th based on the speed switching dial 9 can be achieved.

[0219] ​​​

[0220] On the other hand, the cut-off portion 261 provided on the protrusion 260 of the mode switching ring 6 is offset relative to the vibration switching plate 234 in the circumferential direction. Accordingly, the vibration switching plate 234 is in the retracted position. Figure 19 E).

[0221] In this drilling mode, after mounting the drill bit B onto the anvil 8, pressing the trigger 18 turns on the switch 17. Power is then supplied to the motor 4, causing the rotating shaft 53 to rotate together with the rotor 46.

[0222] Therefore, the input from the input gear 74 is reduced and transmitted to the spindle 165 at the speed selected in the reduction unit 75. The inner hammer 166, outer hammer 167, hammer sleeve 168, and spindle 165 rotate together, and the anvil 8 is rotated by means of the arms 172. Accordingly, the workpiece can be pierced or otherwise machined using the tool head B.

[0223] At this time, even if the torque on the cutter head B and the anvil 8 increases, the impact part 76 will not strike because the retraction of the inner hammer 166 is restricted. In addition, since the vibration switching plate 234 is in the retracted position, the anvil 8 will not vibrate due to the vibration part 77.

[0224] (2) Vibratory drilling mode

[0225] like Figure 20 As shown in A, the mode conversion ring 6 is transformed into a vibratory drilling mode by turning left at a specified angle when viewed from the main view, starting from the drilling mode.

[0226] In vibratory drilling mode, the guide plate 265 is in a right-hand rotating position, and the first and second mountain-shaped portions 275 and 276 of the thick-walled portion 274 are in positions allowing the left and right bars 308 and 309 to move back and forth. The mode conversion lever 280 is in a retracted position because the guide protrusion 284 is located at the end of the first slit 267. Accordingly, the hammer sleeve 168 is in the forward position, thus restricting the retraction of the inner hammer 166. Figure 20 (B~D).

[0227] The locking pin 302 of the linkage lever 301 is engaged with the first end 298 of the guide end 297 of the linkage winding part 295, allowing forward movement in this state. Accordingly, the speed switching retainer 153 can move back and forth, and the speed switching gear 151 can also be rotated, thus enabling selection of speeds 1-4 based on the speed switching dial 9.

[0228] On the other hand, the cut-off portion 261 provided on the protrusion 260 of the mode switching ring 6 is located in front of the tapered portion 258 of the vibration switching plate 234. Accordingly, the vibration switching plate 234 advances, causing the limiting ring 232 to advance to the engagement position where it engages with the rear cam 231.Figure 20 E).

[0229] In this vibration drilling mode, the bit B is attached to the anvil 8, and the switch 17 is turned on by pressing the trigger 18. Then, the motor 4 is supplied with power, and the rotating shaft 53 rotates together with the rotor 46.

[0230] Then, the input from the input gear 74 is reduced at the speed selected in the reduction unit 75, and is transmitted to the main shaft 165. The inner hammer 166 rotates together with the outer hammer 167, the hammer sleeve 168, and the main shaft 165, and the anvil 8 is rotated by the arm portions 172, 172. Accordingly, the bit B can be used to perform a hole boring of a workpiece or the like.

[0231] At this time, since the rotation of the rear cam 231 is restricted, when the bit B is pressed against the workpiece and the anvil 8 is retracted, the front cam 230 and the rear cam 231 are engaged. Accordingly, the anvil 8 is vibrated in the axial direction.

[0232] Also, even if the torque against the bit B and the anvil 8 is increased, since the retraction of the inner hammer 166 is restricted, the hammering by the hammering unit 76 does not occur.

[0233] (3) Impact large mode

[0234] As shown in Fig. 2A, the mode conversion ring 6 is formed in a position where it is turned left at a predetermined angle from the vibration drilling mode in the front view to the impact large mode. Figure 21 A

[0235] In the impact large mode, the guide plate 265 is also turned left, and the guide protrusion 284 of the mode conversion lever 280 relatively moves to the third slit 269 via the second slit 268. Accordingly, the mode conversion lever 280 advances to the intermediate position. Then, the link portions 286, 286 of the mode conversion yoke 285 are swung about the fulcrums 289, 289. Accordingly, the upper end locking pins 290, 290 are retracted to the intermediate positions of the guide holes 291, 291, and the hammer sleeve 168 is slid to the intermediate position (B to E). In this intermediate position, as described above, the middle groove portion 212 of the outer fitting groove 210 is positioned outside the holding slit 201. Figure 21 B to E

[0236] In addition, the cutout portion 261 provided in the protrusion 260 of the mode conversion ring 6 is offset in the circumferential direction with respect to the vibration switching plate 234. Accordingly, the vibration switching plate 234 is in the retracted position (B to E). Figure 21 E

[0237] On the other hand, the guide plate 265 causes the first mountain-shaped portion 275 of the thick-walled portion 274 to move forward of the left rod 308. Additionally, it causes the front flat portion 278 of the second mountain-shaped portion 276 to move forward of the right rod 309. Accordingly, the forward movement of the left and right rods 308 and 309 is restricted.

[0238] Furthermore, the linkage winding section 295 also rotates to the left, causing the locking pin 302 of the linkage rod 301 to move relative to the third end 300 from the first end 298 via the second end 299. Accordingly, the linkage rod 301 slides to the forward position, causing the speed switching holding member 153 and the linkage cam 305 to advance to the forward position.

[0239] At this time, the inclined edge of the linkage cam 305 abuts against the left bar 308, which restricts its forward movement, as it moves forward. Consequently, the linkage cam 305 slides to the right due to the guidance of the inclined edge, causing the speed switching gear 151 to rotate to the 3rd gear position via the eccentric pin 152. The right bar 309 does not interfere with the sliding of the linkage cam 305. Thus, the backward movement and leftward sliding of the linkage cam 305 are restricted, thereby limiting the rotation of the speed switching gear 151 and the speed switching dial 9. Therefore, the 3rd gear of the reduction gear 75 is fixed.

[0240] In this high-impact mode, after assembling the cutter head B onto the anvil 8, pressing the trigger 18 turns on the switch 17. Power is then supplied to the motor 4, causing the rotating shaft 53 and the rotor 46 to rotate together.

[0241] Therefore, the input from the input gear 74 is reduced in speed at the third gear in the reduction section 75 and transmitted to the main shaft 165. The inner hammer 166 rotates together with the outer hammer 167, the hammer sleeve 168, and the main shaft 165, and the anvil 8 is rotated by means of the arms 172. Accordingly, screw tightening and the like can be performed using the cutter head B. At this time, due to the generation of centrifugal force, the three outermost of the five engaging balls 216 move radially outward. Accordingly, as described above, the outer hammer 167 and the hammer sleeve 168 also rotate together with the inner hammer 166.

[0242] When the torque of the anvil 8 increases due to screw tightening, such as Figure 30 As shown, the inner hammer 166 causes the cam balls 183, 183 to rotate along the inner cam grooves 180, 180 of the main shaft 165, and retracts while rotating, overcoming the forces of the two outer and inner disc springs 169, 170. At this time, the two engaging balls 216 of the inner fitting groove 185 retract within the support groove 204 of the outer hammer 167. The three radially outer engaging balls 216 are configured to span the retaining slit 201 of the outer hammer 167 and the central groove 212 of the hammer sleeve 168. Accordingly, the outer hammer 167 and the hammer sleeve 168 rotate in accordance with the rotation of the inner hammer 166 along the inner cam groove 180.

[0243] And, when the claws 181, 181 are separated from the arm portions 172, 172, the inner hammer 166 is caused to advance while rotating together with the outer hammer 167 and the hammer sleeve 168, and the claws 181, 181 are caused to engage with the arm portions 172, 172 again, due to the urging of the outer-inner coil springs 169, 170 and the guidance of the inner cam grooves 180, 180. Accordingly, the rotational striking force (impact) is generated at the anvil 8. Further tightening can be performed by repeating this process. Since this impact is generated by applying the mass of the outer hammer 167 and the hammer sleeve 168 to the inner hammer 166, the total inertial force increases (about 3.7 times in the small impact mode). And, since it is limited to 3 stages and is caused to rotate, even if the torque increases, it is difficult to cause disengagement.

[0244] Here, two outer-inner coil springs 169, 170 with a shorter free length are used in the same number. Accordingly, it is possible to increase the elastic energy of the inner hammer 166 at the time of retreat to the limit. On the other hand, since it is possible to reduce the force acting on the inner hammer 166 at the time of advance, even if two outer-inner coil springs 169, 170 are adopted, it is possible to reduce the mounting load. In addition, it is easy to cause retreat of the inner hammer 166 (the timing at which the claw 181 of the inner hammer 166 passes over the arm portion 172 of the anvil 8 is advanced).

[0245] (4) Small impact mode

[0246] As shown in A, the mode conversion ring 6 is formed in the small impact mode from the position in which it is turned left at a prescribed angle in the main view from the large impact mode. Figure 22 In the small impact mode, the guide plate 265 is also turned left, so that the guide protrusion 284 of the mode conversion lever 280 relatively moves toward the fifth slit 271 via the fourth slit 270. Accordingly, the mode conversion lever 280 advances to the advanced position. Then, the link portions 286, 286 of the mode conversion fork 285 advance so as to swing about the fulcrums 289, 289. Accordingly, the upper end stop pins 290, 290 retreat to the retreat position of the guide holes 291, 291, so that the hammer sleeve 168 slides to the retreat position (B to E).

[0247] Figure 22 B ~ E).

[0248] In addition, the cutout portion 261 provided at the protrusion 260 of the mode conversion ring 6 is offset in the circumferential direction with respect to the vibration switching plate 234. Accordingly, the vibration switching plate 234 is in the retreat position (E). Figure 22

[0249] ​​On the other hand, the guide plate 265 causes the first mountain portion 275 of the thick wall portion 274 to retreat from the front of the left rod 308 toward the left side. In addition, the rear flat portion 277 of the second mountain portion 276 is caused to move toward the front of the right rod 309. Thereby, the advance of the left rod 308 is permitted, and the right rod 309 retreats while abutting against the slope of the second mountain portion 276.

[0250] Also, the link winding portion 295 turns left, but the position of the hook pin 302 of the link lever 301 remains the third end portion 300. Thereby, the link lever 301 and the speed change holder 153 do not change in the advanced position.

[0251] However, with respect to the link cam 305, the right rod 309, which retreats while abutting against the second mountain portion 276, abuts against the slope. Thereby, the link cam 305 slides to the left side by the guidance of the slope, and the speed change gear 151 is caused to rotate to the 4th position by the eccentric pin 152. The left rod 308 abuts against the slope by the sliding of the link cam 305, and thereby advances between the first mountain portion 275 and the second mountain portion 276. In this way, the retreat and the sliding to the right side of the link cam 305 are restricted, and thereby the rotation of the speed change gear 151 and the speed change dial 9 is restricted, and therefore, the 4th position of the speed reduction portion 75 is fixed.

[0252] In this impact small mode, after the bit B is fitted to the anvil 8, the trigger 18 is depressed to turn on the switch 17. Then, the motor 4 is supplied with power to rotate the rotation shaft 53 together with the rotor 46.

[0253] Then, the input from the input gear 74 is reduced in speed by the speed reduction portion 75 in the 4th position and is transmitted to the main shaft 165. The inner hammer 166 rotates together with the main shaft 165, and the anvil 8 is caused to rotate by the arm portions 172, 172. Thereby, screw fastening and the like can be performed using the bit B.

[0254] In the retreat position of the hammer sleeve 168, as described above, the deepest front groove portion 213 of the outer fitting groove 210 is located outside the holding slit 201 of the outer hammer 167. Thereby, the 5 coupling balls 216 are all moved to the radially outer side due to the centrifugal force. Therefore, with respect to the inner hammer 166, the inner side 2 coupling balls 216 are separated from the radially outer side to the inner fitting groove 185. Thereby, only the inner hammer 166 rotates integrally with the main shaft 165.

[0255] When screw fastening is performed so that the torque of the anvil 8 is increased, the inner hammer 166 rotates the cam balls 183, 183 along the inner cam grooves 180, 180 of the spindle 165, and retreats while rotating against the urging of the two outer-inner coil springs 169, 170. Also, when the claws 181, 181 are separated from the arm portions 172, 172, the inner hammer 166 rotates while advancing due to the urging of the outer-inner coil springs 169, 170 and the guidance of the inner cam grooves 180, 180, thereby causing the claws 181, 181 to engage with the arm portions 172, 172 again. Accordingly, the anvil 8 generates a rotational impact force (impact). Further fastening can be performed by repeating this process. The impact at this time is generated by the inner hammer 166 alone at 4 stages, and therefore, even if high speed, the torque is low. Accordingly, it is possible to suppress disengagement and overfastening.

[0256] (5) Screwdriver (clutch) mode

[0257] The display portion 27 is operated in the state of the drilling mode or the vibration drilling mode, whereby the screwdriver mode can be selected.

[0258] In the screwdriver mode, the controller 25 monitors the output torque (motor current, rotation speed) of the motor 4. When the output torque is equal to or greater than a prescribed value, the controller 25 stops the rotation of the motor 4. The prescribed value of the output torque can be changed by selecting the stage number on the display portion 27.

[0259] In the case of the screwdriver mode, the selection of 1 stage to 4 stages based on the speed switching dial 9 can be achieved in the reduction portion 75.

[0260] On the other hand, in each of the operation modes, the fan 35 rotates together with the rotation of the rotation shaft 53. Thus, external air is drawn in from the air intake port 16 and passed through the main body portion 12 to cool the motor 4. Then, the air is delivered to the radial outside of the fan 35 and discharged to the outside through the air exhaust ports 33. As described above, with respect to the upper two air exhaust ports 33A, 33A, the air is guided upward by the inner edge and discharged upward. Accordingly, foreign matter is less likely to intrude into the air exhaust ports 33A, 33A from above.

[0261] In addition, the lamp 21 is lit to irradiate the front of the bit B at the same time as the switch 17 is turned on. Accordingly, even in a dark place, work can be performed without obstacles. It is also possible to arbitrarily turn the lamp 21 on / off by a touch operation of the display portion 27.

[0262] (Effects of the invention in which the operation mode and the speed stage correspond)

[0263] The impact driver 1 of the above-described aspect has a motor 4, a reduction portion 75 that reduces rotation generated by the motor 4, and a striking portion 76 and a vibrating portion 77 (a plurality of working portions) that can work by rotation reduced by the reduction portion 75. The impact driver 1 has a linkage switching portion 78 (a switching portion) that selects the striking portion 76 and the vibrating portion 77 and causes them to work in a drilling mode, a vibration drilling mode, an impact large mode, and an impact small mode (predetermined operation modes), and the reduction portion 75 can select four stages of shift stages.

[0264] Further, the linkage switching portion 78 causes the reduction portion 75 to perform a linkage operation in correspondence with selection of the striking portion 76 (a specific working portion) and causes the reduction portion 75 to work in three gears and four gears (predetermined shift stages) corresponding to the impact large mode and the impact small mode of the striking portion 76, respectively.

[0265] According to this structure, even in the case of the reduction portion 75 that can achieve four stages of shift, the plurality of operation modes of the drilling mode, the vibration drilling mode, the impact large mode, and the impact small mode and the shift stages can be appropriately corresponded.

[0266] The reduction portion 75 can select four stages of shift stages. According to this, even the mechanical reduction portion 75 has an expanded selection range, and the ease of use is excellent. Further, a shift stage suitable for the plurality of operation modes can be selected.

[0267] The working portion includes the striking portion 76 that strikes the anvil 8 in the rotation direction, and the working portion that determines the shift stage is the striking portion 76 whose operation mode is the impact large mode and the impact small mode. According to this, it can be used in an appropriate shift stage corresponding to the striking force.

[0268] The impact mode can be switched to either the impact large mode in which the striking force against the anvil 8 is large or the impact small mode in which the striking force is larger than that of the impact large mode. Further, the linkage switching portion 78 causes the reduction portion 75 to perform a linkage operation in such a manner that the shift stage of the impact small mode (four gears here) is higher in speed than that of the impact large mode (three gears here). According to this, even if the impact mode is two types, it can be used in an appropriate shift stage. In the impact large mode, it is possible to reduce stripping and expect an increase in torque, and in the impact small mode, it is possible to increase the work speed and reduce breakage or overfastening of a screw.

[0269] The linkage switching portion 78 can be switched to the drilling mode in which the anvil 8 is not struck by the striking portion 76, and in the drilling mode, four stages of shift stages based on the reduction portion 75 can be selected. According to this, it is possible to make the ease of use in the drilling mode good.

[0270] The working section includes a vibration section 77 that causes the anvil 8 to vibrate in the axial direction. Also, the linkage switching section 78 is capable of switching to a vibration drilling mode in which the anvil 8 is caused to vibrate by the vibration section 77 without being struck by the striking section 76, and in the vibration drilling mode, a shift stage of 4 stages based on the reduction section 75 can be selected. Thereby, it is possible to make the ease of use in the vibration drilling mode good.

[0271] The reduction section 75 has a speed switch holder 153 and a linkage cam 305 (position changing member) that change positions for each shift stage, and the linkage switching section 78 has a mode conversion ring 6 (mode switching member) for selecting operation of the working section. Also, between the speed switch holder 153 and the linkage cam 305 and the mode conversion ring 6, a guide plate 265, a linkage winding section 295, a linkage lever 301, a left rod 308, and a right rod 309 (linkage members) are provided that cause the speed switch holder 153 and the linkage cam 305 to forcibly move to positions of prescribed shift stages (here, 3rd and 4th) in correspondence with operation of the mode conversion ring 6.

[0272] Thereby, the shift stage suitable for the operation mode is selected in correspondence with operation of the mode conversion ring 6 and automatically.

[0273] The mode conversion ring 6 is capable of selecting the striking section 76 and the vibration section 77 by rotation operation. Thereby, it is possible to easily perform switching of the operation mode by the mode conversion ring 6.

[0274] The reduction section 75 is housed in a cylindrical rear gear case 60 (housing), has an inner gear 81A to 81C that forms 3 stages in the axial direction, planetary gears 80A to 80C that perform revolution motion inside the inner gears 81A to 81C, and a rear gear carrier 85 and a front gear carrier 130 that support the planetary gears 80A to 80C. Thereby, it is possible to obtain a reduction section in which the shift stage is easily set.

[0275] The reduction portion 75 is provided so that two internal gears 81A and 81B adjacent in the axial direction and having different reduction ratios can rotate respectively. In addition, the reduction portion 75 is provided with a speed switching plate 110 (a locking member) that selectively locks either one of the internal gears 81A and 81B to restrict rotation. Further, the other internal gear 81C is provided so as to be able to rotate and so as to be able to slide in the axial direction between a retreat position (a first sliding position) in which the rotation is restricted in the rear side gear housing 60 so that the planetary gear 80C performs a revolution motion, and an advance position (a second sliding position) in which the rotation is not restricted in the rear side gear housing 60 and engages with the planetary gear 80C and the front gear frame 130 at the same time. Further, the rotation restriction of one of the two internal gears 81A and 81B and the sliding position of the one internal gear 81C are combined based on the speed switching plate 110, whereby four stages of reduction stages can be selected.

[0276] Accordingly, even the mechanical reduction portion 75 can achieve four stages of reduction.

[0277] The speed switching plate 110 is provided so that the middle portion is supported and the both end portions are able to swing. The speed switching plate 110 can be switched to a rear tilt posture (a first swing posture) in which one end portion is locked to the outer periphery of one internal gear 81A and the other end portion is not locked to the outer periphery of the other internal gear 81B, and a front tilt posture (a second swing posture) in which one end portion is not locked to the outer periphery of the internal gear 81A and the other end portion is locked to the outer periphery of the internal gear 81B. Accordingly, the rotation restriction and the release thereof of the two internal gears 81A and 81B can be simply performed by the swing of one speed switching plate 110.

[0278] The speed switching ring 114 (a ring-shaped member) is provided on the outer side of the speed switching plate 110 of the rear side gear housing 60 so as to be able to rotate. In the speed switching ring 114, a rear pressing portion 115 (a first pressing portion) that presses one end portion of the speed switching plate 110 to switch the speed switching plate 110 to the rear tilt posture, and a front pressing portion 116 (a second pressing portion) that presses the other end portion to switch the speed switching plate 110 to the front tilt posture are alternately provided at a predetermined angle in the rotation direction. Further, by the rotation operation of the speed switching dial 9 (a rotation operation member) provided in the rear side gear housing 60, the speed switching ring 114 can be rotated to achieve the selective rotation restriction of the internal gears 81A and 81B.

[0279] Accordingly, the posture switching of the speed switching plate 110 can be performed using the speed switching ring 114 and the speed switching dial 9 easily and with a small space.

[0280] A plurality of teeth 121 are circumferentially provided on the speed switching ring 114, and a speed switching dial 9 is provided with a pinion 126 (gear) that engages with the teeth 121, and the speed switching ring 114 is able to rotate by a rotation operation of the speed switching dial 9.

[0281] Accordingly, the posture switching of the speed switching plate 110 can be achieved by a rotation operation of the speed switching dial 9.

[0282] The impact driver 1 of the above-described aspect has a motor 4, a reduction unit 75 that is driven by the motor 4 and that is able to select a prescribed speed change stage, an inner hammer 166 (hammer) that performs a striking operation using the reduction unit 75, and a linkage switching unit 78 (switching unit) that is able to switch the speed change of the reduction unit 75 and whether the inner hammer 166 is able to perform a striking operation. Also, in a case where the inner hammer 166 is able to perform a striking operation, the linkage switching unit 78 restricts the selection of the speed change stage of the reduction unit 75, and in a case where the inner hammer 166 is not able to perform a striking operation, the linkage switching unit 78 is able to perform the selection of the speed change stage of the reduction unit 75.

[0283] The impact driver 1 of the above-described aspect has a motor 4, and a reduction unit 75 that is driven by the motor 4 and that is able to select a prescribed speed change stage, and that is able to be driven in each of a drilling mode, a vibration drilling mode, a driver mode, and an impact mode. Also, the impact driver 1 is able to perform the selection of the speed change stage of the reduction unit 75 in the drilling mode, the vibration drilling mode, and the driver mode, and in the impact mode (impact large mode and impact small mode), the selection of the speed change stage of the reduction unit 75 is restricted.

[0284] Accordingly, in the impact mode (impact large mode and impact small mode), it is possible to always use an appropriate speed change stage.

[0285] Regarding the invention in which the operation mode and the speed change stage are made to correspond, the following changes can be made.

[0286] The speed change stage of the reduction unit is not limited to four stages, and can be three stages or five stages or more.

[0287] In the above-described aspect, in the impact large mode, the speed change stage is made to correspond to three gears, and in the impact small mode, the speed change stage is made to correspond to four gears, but this is not limiting. For example, the same speed change stage can be provided in both modes.

[0288] The impact mode is not limited to two types of the impact large mode and the impact small mode. It is possible to provide an impact mode in which the striking unit has only one hammer and in which only one impact mode is selectable. It is also possible to provide three types of the impact large mode, the impact small mode, and an impact medium mode.

[0289] The operation mode other than the impact mode is not limited to the above-described scheme. It can also be free of any one or two of the drilling mode, the vibration drilling mode, and the screwdriver mode.

[0290] In the above-described scheme, only the impact mode is made to correspond to the prescribed shift stage, but the operation mode other than the impact mode can also be made to correspond to the prescribed shift stage.

[0291] The present application can also be applied even to an impact tool that can select only a plurality of impact modes. The present application can also be applied even to a power tool that does not have an impact mode.

[0292] The shapes of the speed switch holder and the link cam are not limited to the above-described scheme. As the position change member, a member other than the speed switch holder and the link cam can also be used.

[0293] The link member is not limited to the above-described scheme and can be appropriately changed. For example, the link rod can also be formed integrally with the speed switch holder.

[0294] The position change member and the link member can be provided on either side of the left and right sides instead of the lower side of the working unit. They can also be provided inside the housing.

[0295] The motor is not limited to a brushless motor. It can also be an AC tool that does not use a battery pack.

[0296] In the above-described scheme, although a mechanical 4-mode impact screwdriver is exemplified, the present application is not limited to this impact screwdriver. For example, the present application can also be applied to an impact tool such as an impact screwdriver that realizes a screwdriver mode with a mechanical clutch instead of an electronic clutch, an angular impact screwdriver, and a power tool such as a screwdriver drill.

[0297] (Effects of the Invention of the 2 Internal Gears and the Locking Member)

[0298] The impact screwdriver 1 of the above-described scheme has a motor 4, a reduction portion 75 that reduces the rotation generated by the motor 4, and a striking portion 76 and a vibration portion 77 that operate using the rotation reduced by the reduction portion 75. In addition, the reduction portion 75 has internal gears 81A to 81C that form 3 stages in the axial direction, planetary gears 80A to 80C that perform revolution motion inside the internal gears 81A to 81C, and a rear gear carrier 85 and a front gear carrier 130 that support the planetary gears 80A to 80C.

[0299] The reduction gear 75 has a rotatable internal gear 81A (front-stage side internal gear) located at the front stage, and a rotatable internal gear 81B (rear-stage side internal gear) located at the rear stage of the internal gear 81A and having a different reduction ratio from the internal gear 81A. In addition, the reduction gear 75 has a speed switching plate 110 (locking member) disposed at the radially outer side of the internal gears 81A, 81B, and capable of being switched to a rearward tilt posture (first position) in which the internal gear 81A is locked to restrict the rotation of the internal gear 81A, and a forward tilt posture (second position) in which the internal gear 81B is locked to restrict the rotation of the internal gear 81B. Further, the reduction gear 75 has a speed switching ring 114 and a speed switching dial 9 (operation portion) capable of selectively switching the speed switching plate 110 to either of the rearward tilt posture and the forward tilt posture.

[0300] According to this structure, the reduction gear 75 can be made compact in the axial direction, and the speed switching can be smoothly and stably performed.

[0301] The speed switching plate 110 is provided so that the intermediate portion is supported and the both end portions are swingable, one end portion is locked to the outer periphery of the internal gear 81A in the rearward tilt posture, and the other end portion is locked to the outer periphery of the internal gear 81B in the forward tilt posture. Accordingly, the rotation restriction and release of the two internal gears 81A, 81B can be performed with one speed switching plate 110, and the space can be saved and rationalized.

[0302] The reduction gear 75 is housed in the cylindrical rear-stage gear case 60, and the operation portion has the speed switching ring 114 and the speed switching dial 9. Accordingly, the posture switching of the speed switching plate 110 can be performed with the speed switching ring 114, and the space can be saved and easily performed. In particular, a plurality of teeth 121 are continuously formed in the circumferential direction of the speed switching ring 114, and an upper gear 126 is integrally formed in the speed switching dial 9. Accordingly, the speed switching ring 114 can be simply rotated by the rotation operation of the speed switching dial 9.

[0303] A planar gear ring 120 (gear ring) in which the teeth 121 are formed is integrally provided in the speed switching ring 114. Accordingly, the teeth 121 can be simply provided in the speed switching ring 114.

[0304] The speed switching ring 114 is a frame-shaped body in which the rear pressing portion 115 and the front pressing portion 116 protrude in the axial direction and extend in the circumferential direction. Accordingly, the structure of the speed switching ring 114 is simple.

[0305] A plurality of speed switching plates 110 are provided. Accordingly, the rotation restriction of the internal gears 81A, 81B can be reliably performed.

[0306] The speed switching plate 110 is disposed at a point symmetrical position with respect to the axis of the ring gears 81A, 81B. Due to this, the rotation of the ring gears 81A, 81B can be restricted without tilting with respect to the axis.

[0307] On the outer periphery of the ring gears 81A, 81B, a plurality of rear and front locking ribs 91, 95 (locking ribs) extending in the axial direction are provided at regular intervals along the circumferential direction of the ring gears 81A, 81B. Further, on both end portions of the speed switching plate 110, a rear locking portion 112 and a front locking portion 113 are formed which lock with the rear and front locking ribs 91, 95 in the circumferential direction. Due to this, the rotation restriction and release of the ring gears 81A, 81B can be reliably performed.

[0308] The rear and front locking portions 112, 113 are formed in a curled shape. Due to this, locking with the rear and front locking ribs 91, 95 is easy.

[0309] The ring gears 81A, 81B are disposed adjacent in the axial direction with an O-ring 93 (sealing member) interposed between the opposing faces of each other. Further, on the end portions on the opposite sides of the respective opposing faces of the ring gears 81A, 81B, a rear flange portion 90 and a front flange portion 94 are formed which project toward the center side. Due to this, a holding space S is formed between the ring gears 81A, 81B which does not cause the lubricating grease on the radially inner side of the ring gears 81A, 81B to overflow to the outer side, whereby the lubricating grease can be prevented from drying out.

[0310] The impact driver 1 of the above-described aspect has: a motor 4; a rear gear carrier 85 which is driven to rotate by the motor 4; a pin 86 which is held to the rear gear carrier 85; a planetary gear 80A (first planetary gear) which is held to the pin 86 and has a first number of teeth; a planetary gear 80B (second planetary gear) which is held to the pin 86 and has a second number of teeth which is different from the first number of teeth; a ring gear 81A (first ring gear) which meshes with the planetary gear 80A; a ring gear 81B (second ring gear) which meshes with the planetary gear 80B; and a speed switching plate 110 (fixing member) which renders either of the ring gears 81A, 81B non-rotatable.

[0311] According to this structure, the two ring gears 81A, 81B can be selectively rendered non-rotatable by one speed switching plate 110. Due to this, a reduction unit 75 which becomes compact in the axial direction and in which the speed switching can be smoothly and stably performed can be obtained.

[0312] With respect to the invention of the two ring gears and the locking member, the following modifications can be made.

[0313] The two inner gears on the front and rear sides of the speed switch plate (the locking members) are not limited to the first and second stages of the above-described scheme. For example, the inner gears of the second and third stages can also be rotationally restricted by locking members. The number of stages of the speed reduction portion is not limited to four. Multiple sets of locking members and two inner gears can be provided.

[0314] The number of locking members is not limited to two. For example, three or more locking members can be arranged in the circumferential direction of the inner gear to rotationally restrict the inner gear.

[0315] The shape of the locking members is not limited to the speed switch plate of the above-described scheme. The front and rear locking members can not be in a curled shape. For example, the front and rear locking members can be formed by simply bent end portions. The front and rear locking members can also be formed by separate components. For example, the locking members can be formed by an elastic body and the front and rear locking members can be formed by pin members.

[0316] The support of the intermediate portion of the locking members is not limited to the structure of the speed switch holder of the above-described scheme. A partition wall can be directly provided in the housing to support the locking members. The intermediate portion of the locking members can also be supported by pin members.

[0317] The ring-shaped member is not limited to the speed switch ring of the above-described scheme. The ring-shaped member can be a band-shaped body instead of a frame-shaped body that extends in a meandering manner in the circumferential direction. Accordingly, the teeth can not be provided by a separate gear ring, but can be directly formed on the ring-shaped member.

[0318] Multiple sealing members can be provided between the two inner gears related to the speed change. Sealing members other than O-rings can also be used.

[0319] Sealing between the opposing surfaces of the two inner gears can also be performed without using a sealing member. For example, a ring-shaped protrusion can be formed on either of the opposing surfaces and a ring-shaped groove can be formed on the other opposing surface such that the protrusion is inserted into the groove, thereby achieving sealing.

[0320] The two inner gears related to the speed change can not be adjacent in the axial direction. In this case, the sealing member between the opposing surfaces of the inner gears can be omitted. The flange portion can also be omitted.

[0321] The motor is not limited to a brushless motor. The AC tool can not use a battery pack.

[0322] In the above-described scheme, although a mechanical four-mode impact driver is exemplarily described, the present application is not limited to an impact driver, but can also be applied to other impact tools, driver-drills, screwdrivers, and other electric tools having a speed reduction portion that uses a planetary gear and an inner gear.

[0323] (EFFECT OF INVENTION OF LEVER MEMBER)

[0324] The impact driver 1 of the above-described aspect includes the mode switching ring 6 (operation member), the link portion 286 (lever member) of the mode switching yoke 285 that swings with the operation of the mode switching ring 6 via the fulcrum 289, and the hammer sleeve 168 (switching member) that linearly moves in conjunction with the swing of the link portion 286. Further, the fulcrum 289 is inserted into the link portion 286 to enable the link portion 286 to swing, and the insertion portion of the fulcrum 289 of the link portion 286 is an oblong hole 288 (long hole) that extends along the link portion 286.

[0325] According to this structure, even if the link portion 286 swings with the fulcrum 289 as the center, the axis of the hammer sleeve 168 and the moving locus of the end portion of the link portion 286 are parallel. Thereby, even if the stroke amount of the hammer sleeve 168 increases, the possibility that the link portion 286 falls off from the hammer sleeve 168 or that the switching of the operation mode is not properly performed is reduced. That is, the switching of the operation mode can be smoothly performed. Further, the assemblability of the link portion 286 is also improved.

[0326] The hammer sleeve 168 is provided inside the front-side gear housing 61, the mode switching ring 6 and the link portion 286 are provided outside the front-side gear housing 61, and the fulcrum 289 protrudes from the outer surface of the front-side gear housing 61. Thereby, even if the front-side gear housing 61 is passed over, the hammer sleeve 168 can be smoothly linearly moved. The assembly of the mode switching yoke 285 can also be easily performed outside the front-side gear housing 61.

[0327] The linkage of the link portion 286 and the hammer sleeve 168 is performed by the locking pin 290 provided at the end portion of the link portion 286 being locked to the hammer sleeve 168. Thereby, the swing of the link portion 286 can be converted into the linear movement of the hammer sleeve 168.

[0328] The locking pin 290 is locked to the hammer sleeve 168 via the linear guide hole 291 provided in the front-side gear housing 61 along the linear movement direction of the hammer sleeve 168. Thereby, the movement of the locking pin 290 along the axis direction of the hammer sleeve 168 can be guided.

[0329] The striking portion 76 including the main shaft 165 and the inner hammer 166 (hammer) that is attached to the main shaft 165 is provided inside the front-side gear housing 61, and the switching member is the hammer sleeve 168 (sleeve member) that is attached to the inner hammer 166 to be movable in the axis direction. Thereby, the switching of the impact mode of the striking portion 76 can be smoothly performed.

[0330] The annular groove 215 is formed in the outer periphery of the hammer sleeve 168, and the locking pin 290 is locked to the annular groove 215. Thereby, the hammer sleeve 168 can be smoothly linearly moved.

[0331] The link portions 286 are provided in pairs, one end portion of which is linked to each other by a link portion 287 that swings with the operation of the mode switching ring 6, and a locking pin 290 provided at the other end portion of each link portion 286 is locked in the ring groove 215, respectively. Accordingly, the hammer sleeve 168 can be reliably moved linearly.

[0332] The locking pins 290 are disposed at a point-symmetrical position with the axis of the hammer sleeve 168 as the center. Accordingly, the hammer sleeve 168 is less likely to be tilted.

[0333] The mode switching ring 6 is provided for switching the operation mode. Accordingly, the linear movement of the hammer sleeve 168 in conjunction with the switching of the operation mode can be performed.

[0334] The mode switching ring 6 is switched by a rotational operation to switch the operation mode. Accordingly, the switching of the operation mode can be easily performed.

[0335] The impact masher 1 of the above-described aspect has a motor 4, an anvil 8 that is driven to rotate by the motor 4, an inner hammer 166 that strikes the anvil 8 in the rotational direction, and a hammer sleeve 168 that is attached to the inner hammer 166 for switching the operation mode. In addition, the impact masher 1 has a ring groove 215 provided at the outer periphery of the hammer sleeve 168, a locking pin 290 (locking portion) that is locked in the ring groove 215, and a link portion 286 that moves the locking pin 290 only in the axial direction of the hammer sleeve 168.

[0336] In this configuration, the link portion 286 is less likely to be detached from the hammer sleeve 168 or to cause switching failure at the time of switching the operation mode. Accordingly, the switching of the operation mode can be smoothly performed. In addition, the link portion 286 is also good in assembly.

[0337] The invention for the link member can be changed as follows.

[0338] The long hole provided at the link portion is not limited to an oblong hole, but can be an elliptical hole. It can also be a square hole.

[0339] The locking pin can be integrally provided at the link portion.

[0340] The two link portions can not be linked by the link portion but swing left and right, respectively.

[0341] The link portion can be located inside the housing.

[0342] The link member can be used for switching the operation mode other than the impact mode. Accordingly, the switching member can be, for example, a ring gear provided at a speed reduction portion for speed change.

[0343] In the above-described arrangement, the support shaft is provided in the gear housing and the long hole is provided in the link portion, but the reverse arrangement is also possible. That is, even if the support shaft is provided in the link portion and the long hole is provided in the gear housing, the switching members such as the hammer sleeve and the internal gear can be moved only in the axial direction.

[0344] The motor is not limited to a brushless motor. The AC tool that does not use a battery pack is possible.

[0345] The present application is also applicable to electric power tools other than the impact driver.

[0346] The present application is not limited to electric power tools, and is applicable to work tools driven by air or an engine.

[0347] (Effects of the present application in which the planetary gears overlap each other)

[0348] The impact driver 1 of the above-described arrangement has a motor 4, a reduction portion 75 that reduces the rotation generated by the motor 4, and a striking portion 76 and a vibration portion 77 that operate by the rotation reduced by the reduction portion 75. Further, the reduction portion 75 has three-stage internal gears 81A to 81C formed in the axial direction, a plurality of planetary gears 80A to 80C that revolve in the internal gears 81A to 81C, and a rear gear carrier 85 and a front gear carrier 130 that support the respective planetary gears 80A to 80C by means of pins 86, 131. Further, the respective planetary gears 80A of the front stage and the respective planetary gears 80B of the rear stage that are adjacent in the axial direction are supported in a state of overlapping each other in the radial direction by one pin 86.

[0349] According to this structure, a reduction portion 75 that is compact in the axial direction and has high durability can be obtained.

[0350] The planetary gear 80A of the front stage is provided with a gear portion 83 adjacent to the planetary gear 80B of the rear stage and a bearing portion 84 that extends to the inner diameter side of the planetary gear 80B, and the planetary gear 80B is fitted in and overlaps the bearing portion 84. Accordingly, the planetary gears 80A, 80B can be compactly overlapped with each other. Further, since the planetary gear 80B does not contact the pin 86, mechanical loss due to frictional resistance when the planetary gear 80B is used can be reduced.

[0351] A bearing 87 is provided between the bearing portion 84 and the pin 86. Accordingly, the two planetary gears 80A, 80B can be supported by one bearing 87.

[0352] The bearing 87 is a needle bearing. Accordingly, the radial direction becomes more compact. Further, even if the grease dries, necessary lubrication can be achieved.

[0353] The front internal gear 81A and the rear internal gear 81B are configured to rotate independently. Furthermore, a speed switching plate 110, a speed switching ring 114, and a speed switching dial 9 (rotation limiting part) are provided to selectively limit the rotation of the internal gears 81A and 81B. Accordingly, two speed levels can be easily achieved by switching the rotation limits of the two internal gears 81A and 81B.

[0354] The following modifications can be made to the invention where planetary gears overlap.

[0355] Overlapping planetary gears are not limited to the first and second stages. For example, the second and third stage planetary gears can overlap each other. The number of stages in the reduction section is also not limited to four.

[0356] In the above scheme, the planetary gear in the front section is provided with a bearing portion, and the planetary gear in the rear section is externally mounted on the bearing portion. However, it can be the opposite. That is, the planetary gear in the rear section can be supported by a pin to form a bearing portion extending towards the front section, and the planetary gear in the front section can be externally mounted on the bearing portion.

[0357] The bearing between the bearing section and the pin can be a bearing other than a needle roller bearing. Alternatively, there may be no bearing at all.

[0358] In the above-described scheme, the second-stage planetary gear is externally mounted on and overlaps with the bearing portion where the first-stage planetary gear is located. However, it is also possible to externally mount the third-stage and subsequent planetary gears on the bearing portion. That is, the present invention also includes a scheme in which planetary gears of three or more stages overlap.

[0359] The motor is not limited to a brushless motor. It can be used for AC tools that do not use a battery pack.

[0360] Although the above scheme illustrates four types of mechanical impact screwdrivers, the present invention is not limited to impact screwdrivers. It can also be applied to other impact tools, screwdrivers, screwdrivers, and other power tools as long as they have a reduction gear with planetary gears and internal gears.

[0361] (Instructions for nail-driving blades)

[0362] In vibratory drilling mode, nails can be driven in using a nail-driving tool. For example... Figure 31 As shown, the nail-driving head B1 has a rotating shaft 330, a head 331, multiple balls 332, 332..., a washer 333, and a rubber sleeve 334.

[0363] The shaft portion 330 is inserted into the bit insertion hole 315 as with the usual bit B. However, the shaft portion 330 has a circular cross-sectional shape, not a regular hexagonal shape. Accordingly, the shaft portion 330 is held so as to be rotatable within the bit insertion hole 315. A necked portion 335 is formed at the rear end of the shaft portion 330. In a state of being inserted into the bit insertion hole 315, the balls 318, 318 of the ball receiving portions 317, 317 are engaged with the necked portion 335.

[0364] The head portion 331 is provided integrally with the shaft portion 330. The head portion 331 is a large-diameter circular shape, and the front end surface is flat except for the outer peripheral portion. An annular engagement groove 336 is formed at the outer periphery of the head portion 331 on the front side. An annular recessed portion 337 is formed at the rear surface of the head portion 331 and at the root of the shaft portion 330. The balls 332, 332,... are fitted into the annular recessed portion 337.

[0365] The washer 333 is penetrated by the shaft portion 330 at the rear of the head portion 331, and receives the balls 332, 332,....

[0366] The rubber sleeve 334 is provided so as to cover the head portion 331 and the washer 333. An annular front necked portion 338 and an annular rear necked portion 339 are formed at the front and rear ends of the rubber sleeve 334, respectively, so as to be folded back toward the center side. The front necked portion 338 is engaged with the engagement groove 336 of the head portion 331. The rear necked portion 339 is engaged with the rear end of the washer 333. Accordingly, the washer 333 is coupled to the head portion 331 in a state of abutting against the balls 332.

[0367] The nailing bit B1 is such that the shaft portion 330 is inserted into the bit insertion hole 315 as with the bit B. Then, the balls 318, 318 of the ball receiving portions 317, 317 are engaged with the necked portion 335, and thus the bit is prevented from coming off. At the same time, the washer 333 abuts against the front end surface of the anvil 8. In this state, the rear end of the head portion 331 does not abut against the washer 333.

[0368] In the case of nailing, the front end surface of the head portion 331 is made to abut against the head of the nail, and the impact driver 1 is operated in a vibration drilling mode. Then, the vibration in the front-rear direction generated by the anvil 8 is transmitted to the nail via the head portion 331. Accordingly, when the impact driver 1 is pressed, the nail can be driven into the workpiece. At this time, even if the washer 333 follows the rotation of the anvil 8, since the balls 332, 332,... between the head portion 331 and the washer 333 cut off the transmission of the rotation, the head portion 331 does not rotate.

[0369] The nailing bit B1 can also be used in impact drivers other than the mechanical 4-mode impact drivers of the above-described embodiment, and electric power tools (electric power tools having a vibration mode, and having a hexagonal hole at the final output shaft so that the bit can be attached and detached).

Claims

1. A power tool having: a motor; a reduction section that reduces rotation generated by the motor; and a working section that works by rotation reduced by the reduction section, the reduction section having, in an axial direction, at least two stages of an internal gear, a plurality of planetary gears that revolve within the internal gear, and a carrier that respectively supports each of the planetary gears by a pin, the power tool characterized in that each of the planetary gears of a preceding stage adjacent in the axial direction and at least one stage of the planetary gears on a succeeding stage side are respectively supported to the same pin in a state of being radially overlapped with each other, a gear portion adjacent to the planetary gears of the succeeding stage is provided to the planetary gears of the preceding stage, and a bearing portion extending to an inner diameter side of the planetary gears of the succeeding stage is provided, the planetary gears of the succeeding stage being fitted to the bearing portion and being overlapped therewith.

2. The power tool according to claim 1, characterized in that a bearing is provided between the bearing portion and the pin.

3. The power tool according to claim 2, characterized in that the bearing is a needle bearing.

4. The power tool according to any one of claims 1 to 3, characterized in that the internal gear of the preceding stage for engaging the planetary gears of the preceding stage and the internal gear of the succeeding stage for engaging the planetary gears of the succeeding stage are arranged adjacent in the axial direction with a sealing member interposed between opposite surfaces of each other, and flange portions projecting toward a center side are respectively formed at end portions on opposite sides of the opposite surfaces of each of the internal gear of the preceding stage and the internal gear of the succeeding stage.

5. The power tool according to claim 4, characterized in that the internal gear of the preceding stage and the internal gear of the succeeding stage are arranged to be able to rotate respectively, and a rotation restricting portion that selectively restricts rotation of the internal gear of the preceding stage and the internal gear of the succeeding stage is provided.

6. The power tool according to claim 5, characterized in that the rotation restricting portion has: a locking member arranged on a radially outer side of the internal gear of the preceding stage and the internal gear of the succeeding stage, and able to be switched to a first position in which the locking member is locked to the internal gear of the preceding stage to restrict rotation of the internal gear of the preceding stage, and a second position in which the locking member is locked to the internal gear of the succeeding stage to restrict rotation of the internal gear of the succeeding stage; and an operation portion that is able to selectively perform switching operation of the locking member to either one of the first position and the second position.

7. The power tool according to claim 6, characterized in that the locking member is arranged such that a middle portion is supported and both end portions are able to swing, one end portion is locked to an outer periphery of the internal gear of the preceding stage in the first position, and the other end portion is locked to an outer periphery of the internal gear of the succeeding stage in the second position.

8. The power tool according to claim 7, characterized in that the reduction section is housed in a cylindrical housing, and the operation portion has: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a ring-shaped member which is provided so as to be rotatable along the outer periphery of the housing and which is alternately formed in the circumferential direction with a first pressing portion which presses the one end portion of the locking member from the radially outer side of the housing to cause the locking member to switch to the first position, and a second pressing portion which presses the other end portion of the locking member from the radially outer side to cause the locking member to switch to the second position; and a rotation operation member which rotates the ring-shaped member at an arbitrary angle in the outer periphery of the housing.

9. The power tool according to claim 8, wherein a plurality of teeth are continuously formed in the circumferential direction in the ring-shaped member, a gear which engages with the teeth is integrally formed in the rotation operation member.

10. The power tool according to claim 9, wherein a gear ring in which the teeth are formed is integrally provided in the ring-shaped member.

11. The power tool according to any one of claims 8 to 10, wherein the ring-shaped member is a frame-shaped body in which the first pressing portion and the second pressing portion protrude in the axial direction so as to be different from each other and extend in the circumferential direction in a meandering manner.

12. The power tool according to any one of claims 6 to 10, wherein a plurality of the locking members are provided.

13. The power tool according to claim 12, wherein the locking members are disposed at positions which are symmetric with respect to a point centered on the axis of the inner gear.

14. The power tool according to any one of claims 6 to 10 and 13, wherein a plurality of locking ribs which extend in the axial direction are provided at a predetermined interval in the circumferential direction of the inner gear of the front stage and the inner gear of the rear stage, locking portions which lock with the locking ribs in the circumferential direction are formed at both end portions of the locking member.

15. The power tool according to claim 14, wherein the locking portions are formed in a curled shape.

16. A power tool having: a motor; a deceleration section that decelerates rotation generated by the motor; and a working portion which works by rotation which is decelerated by the deceleration portion, the deceleration portion has, in the axial direction, an inner gear which is formed in at least two stages, a plurality of planetary gears which revolve in the inner gear, and a carrier which supports each of the planetary gears by a pin, the power tool is characterized in that each of the planetary gears of a front stage which are adjacent in the axial direction and at least one planetary gear of a rear stage which is located on the rear stage side are supported by the same pin in a state in which they overlap each other in the radial direction, the inner gear of the front stage which engages with the planetary gears of the front stage and the inner gear of the rear stage which engages with the planetary gears of the rear stage are disposed adjacent to each other in the axial direction with a sealing member interposed between opposing surfaces of the inner gears, on the other hand, flange portions which project toward the center side are formed at end portions of the opposing surfaces of the inner gears of the front stage and the inner gears of the rear stage, the inner gear of the front stage and the inner gear of the rear stage are provided so as to be rotatable, respectively, A rotation restriction portion that selectively restricts rotation of the internal gear of the front section and the internal gear of the rear section is provided, The rotation restriction portion has: a locking member disposed radially outward of the internal gear of the front section and the internal gear of the rear section, and capable of being switched to a first position in which the locking member is locked to the internal gear of the front section to restrict rotation of the internal gear of the front section, and a second position in which the locking member is locked to the internal gear of the rear section to restrict rotation of the internal gear of the rear section; and an operation portion capable of selectively switching the locking member to either of the first position and the second position, The locking member is disposed with an intermediate portion supported and both end portions capable of swinging, in the first position, one end portion is locked to the outer periphery of the internal gear of the front section, and in the second position, the other end portion is locked to the outer periphery of the internal gear of the rear section, The reduction portion is housed in a cylindrical housing, The operation portion has: a ring member disposed so as to be capable of rotating along the outer periphery of the housing, and alternately formed in the circumferential direction with a first pressing portion that presses the one end portion of the locking member from the radially outer side of the housing to switch the locking member to the first position, and a second pressing portion that presses the other end portion of the locking member from the radially outer side of the housing to switch the locking member to the second position; and a rotation operation member that rotates the ring member at an arbitrary angle along the outer periphery of the housing.

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