Electric tool and impact tool

Abstract

The invention provides an electric tool and an impact tool, which can restrain the large size of the whole length of the electric tool caused by a screw for fixing a housing. The electric tool includes: a motor; a motor accommodating part for accommodating the motor; a rotation mechanism part including an output part which is disposed forward of the motor and rotates based on the rotational force of the motor; a rotating mechanism housing disposed in front of the motor housing portion and housing at least a portion of the rotating mechanism portion; and a screw member that reaches the rotating mechanism housing from the rear of the motor housing part and fixes the motor housing part and the rotating mechanism housing to each other. The motor is fixed together with the motor accommodating portion and the rotating mechanism housing through a screw member.

Description

Technical Field

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

[0002] In the technical field of power tools, a power tool such as that disclosed in Patent Document 1 is known. In Patent Document 1, a motor and a rotating mechanism including a transmission are arranged front to back and housed within a pair of housings with a left and right split structure. The housings are secured to each other by screws that extend left and right across the space between the motor and the rotating mechanism.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent No. 9,450,472 Summary of the Invention

[0006] In conventional electric power tools, a space for arranging screws for fixing the left and right housings is provided between the motor and the rotating mechanism. Therefore, the total length of the portion that causes the output unit to rotate is increased.

[0007] An object of the technology disclosed in this specification is to suppress an increase in the overall length of an electric power tool due to screws for fixing a housing.

[0008] This specification discloses an electric tool. The electric tool may include: a motor; a motor housing portion that houses the motor; a rotating mechanism portion that includes an output portion disposed forward of the motor and rotated by the motor's rotational force; a rotating mechanism housing disposed forward of the motor housing portion and housing at least a portion of the rotating mechanism portion; and a screw member that extends from the rear of the motor housing portion to the rotating mechanism housing to secure the motor housing portion and the rotating mechanism housing to each other. The motor may be secured to both the motor housing portion and the rotating mechanism housing by the screw member.

[0009] Effects of the Invention

[0010] According to the technology disclosed in this specification, it is possible to suppress an increase in the overall length of the electric power tool due to screws for fixing the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a perspective view showing the electric power tool according to the embodiment as viewed from the front.

[0012] Figure 2 It is a side view showing the electric power tool according to the embodiment.

[0013] Figure 3It is a longitudinal sectional view showing the electric power tool according to the embodiment.

[0014] Figure 4 It is a longitudinal sectional view showing the upper portion of the electric power tool according to the embodiment.

[0015] Figure 5 It is a transverse cross-sectional view showing an upper portion of the electric power tool according to the embodiment.

[0016] Figure 6 It is an exploded perspective view showing the electric power tool according to the embodiment.

[0017] Figure 7 It is an exploded perspective view showing a lamp unit according to the embodiment.

[0018] Figure 8 It is a perspective view showing the bearing holding member and the main shaft according to the embodiment as seen from the rear.

[0019] Figure 9 This is an exploded perspective view showing a bearing and a main shaft support structure according to the embodiment as viewed from the front.

[0020] Figure 10 This is an exploded perspective view showing a bearing and a main shaft support structure according to the embodiment as viewed from the rear.

[0021] Figure 11 It is a longitudinal sectional view showing the peripheral structure of the bearing holding member according to the embodiment.

[0022] Figure 12 It is an exploded perspective view showing a bearing holding member and a hammer case according to the embodiment as seen from the front.

[0023] Figure 13 It is a cross-sectional view showing the bearing holding member according to the embodiment as viewed from the front.

[0024] Figure 14 It is a schematic longitudinal sectional view showing a modified example of the main shaft bearing.

[0025] Figure 15 It is a schematic longitudinal sectional view showing a modified example of the rotor bearing.

[0026] Figure 16 It is a schematic longitudinal sectional view showing a first modified example of the support portion of the rotor bearing.

[0027] Figure 17 It is a schematic longitudinal sectional view showing a second modified example of the support portion of the rotor bearing.

[0028] Figure 18It is an exploded perspective view showing the hammer case and the rear case according to the embodiment as seen from the front.

[0029] Figure 19 It is an exploded perspective view showing the hammer case and the rear case according to the embodiment as seen from the rear.

[0030] Figure 20 It is a cross-sectional view showing a section passing through a screw member for connecting the hammer case and the rear case.

[0031] Figure 21 It is a perspective view showing the rear cabinet according to the embodiment as viewed from the front.

[0032] Figure 22 It is a perspective view showing the motor according to the embodiment as viewed from the front.

[0033] Figure 23 It is a perspective sectional view showing a cross section passing through the stator core.

[0034] Figure 24 It is an exploded perspective view showing a housing according to the embodiment.

[0035] Figure 25 It is a perspective view showing the left housing according to the embodiment.

[0036] Figure 26 It is a perspective view showing the right housing according to the embodiment.

[0037] Figure 27 It is an exploded perspective view showing the connection portion between the left housing and the right housing.

[0038] Figure 28 It is an exploded perspective view showing the rear cabinet, the left housing, and the right housing according to the embodiment.

[0039] Figure 29 It is a longitudinal sectional view for explaining the dimensions of each part of the electric power tool according to the embodiment.

[0040] Figure 30 It is a longitudinal sectional view showing an upper portion of an electric power tool according to another embodiment.

[0041] Figure 31 It is an exploded perspective view showing a bearing holding member, an internal gear, and a hammer case according to another embodiment, as seen from the rear.

[0042] Figure 32 It is a perspective view showing an electric power tool according to another embodiment as viewed from the rear.

[0043] Figure 33It is a perspective view showing an electric power tool according to another embodiment as viewed from the rear.

[0044] Description of Reference Numerals

[0045] 1…Power tool; 1A…Power tool; 1B…Power tool; 2…Casing; 2B…Rear housing; 2L…Left housing; 2R…Right housing; 2S…Screw; 3…Rotating mechanism; 4…Hammer housing (rotating mechanism housing); 4A…First barrel; 4B…Second barrel; 4C…Protrusion; 4D…Connecting boss; 4E…Engaging convex portion; 4F…Engaging concave portion; 4G…Step; 4H…Boss; 4S…Screw member; 4T…Threaded hole; 5…Bearing retaining member; 5H…Boss; 5T…Screw insertion hole; 6…Motor; 7…Reduction mechanism; 8…Spindle; 8A…Flange; 8B…Shaft; 8C…Retaining portion; 8D…Spindle groove; 8E…Spindle concave portion; 8G…Through hole; 9…Striking mechanism; 10…Anvil 10A… tool hole; 10B… anvil boss; 10C… anvil shaft; 10D… anvil protrusion; 11… tool holding mechanism; 12… fan; 13… battery assembly; 14… trigger shifter; 15… forward / reverse switching shifter; 16… operation display; 16A… operation button; 17… mode switching switch; 18… lamp assembly; 18A… lamp housing; 18B… light emitting element; 18C… lamp cover; 18D… engaging rib; 18E… anti-slip component; 19… air inlet; 20… exhaust port; 21… motor housing; 21A… peripheral surface; 21B… rear surface; 21D… support surface; 21H… boss; 21T… screw insertion hole; 22… grip; 22L… left grip; 22 R…right grip; 23…battery holder; 23L…left battery holder; 23R…right battery holder; 24…housing holder; 24A…front opening; 24B…rear opening; 24C…recess; 25…battery pack; 26…stator; 27…rotor; 28…stator core; 29…front insulator; 30…rear insulator; 31…coil; 32…rotor core; 33…rotor shaft; 33A…non-gear portion; 33F…front shaft; 33R…rear shaft; 37…sensor substrate; 37S…screw; 39F…rotor bearing; 39R…rotor bearing; 41…pinion; 42…planetary gear; 42P…pin; 43…internal gear; 43A…engaging protrusion; 44…spindle bearing; 4 4A…radial bearing portion; 44B…thrust bearing portion; 44C…sliding surface; 44D…groove; 45…O-ring; 46…bearing; 47…hammer; 47A…hole; 47B…hammer groove; 47C…recess; 47D…hammer body; 47E…hammer protrusion; 48…ball; 49…coil spring; 50…washer; 51…ball; 55…retaining plate portion; 55A…retaining opening; 55B…engaging recess; 56…peripheral wall portion; 56A…vent; 57…rib; 58A…rib; 58B…first recess; 58C…second recess; 60A…inner ring; 60B…outer ring; 60C…ball; 65…seal member; 66…O-ring; 67…O-ring; 71…ball; 72…leaf spring; 73…sleeve;74…coil spring; 75…positioning member; 76…support recess; 77…annular spring; 78…washer; 81…outer circumferential surface; 82…inner circumferential surface; 85…hammer housing cover; 85A…opening; 90L…boss portion; 90R…boss portion; 91L…boss portion; 91R…boss portion; 95…connecting member; 96L…left support portion; 96R…right support portion; 202…housing; 202L…left housing; 202R…right housing 204…Hammer housing (rotating mechanism housing); 204H…Boss portion; 204S…Screw member; 210…Anvil (output portion); 210A…Anvil shaft portion; 221…Motor housing portion; 222…Handle portion; 222L…Left handle portion; 222R…Right handle portion; 223…Battery holder portion; 224…Casing holder portion; 225…Battery housing; 239F…Rotor bearing; 244…Spindle bearing; 245A…Inner Ring; 245B…Outer ring; 245C…Ball; 246…Flange; 302…Casing; 302L…Left casing; 302R…Right casing; 304…Rotating mechanism housing; 304H…Boss; 304S…Screw member; 310…Output unit; 321…Motor housing; 322…Handle; 322L…Left handle; 322R…Right handle; 323…Battery holder; 323R…Right battery holder; 3 23L…Left battery holder; 324…Casing holder; 325…Rear cover; 400…Side handle; AX…Rotation axis; CP…Contact portion; D11…Rotor core outer diameter; D12…Stator outer diameter; L1…Length; L2…Length; L11…Head length; L12…Distance between motor bearings; L13…Motor thickness; L14…Distance; L15…Distance; L16…Length; L21…Stator thickness; L22…Rotor length. DETAILED DESCRIPTION

[0046] In one or more embodiments, the electric tool may include: a motor; a motor housing portion that houses the motor; a rotating mechanism portion that includes an output portion disposed forward of the motor and that rotates based on the rotational force of the motor; a rotating mechanism housing disposed in front of the motor housing portion and housing at least a portion of the rotating mechanism portion; and a screw member that extends from the rear of the motor housing portion to the rotating mechanism housing to secure the motor housing portion and the rotating mechanism housing to each other. The motor may be secured to both the motor housing portion and the rotating mechanism housing by the screw member.

[0047] According to the above-mentioned structure, the motor in the motor housing portion can be fixed together with the motor housing portion and the rotating mechanism housing by using screw components in the front-to-back direction for fixing the motor housing portion and the rotating mechanism housing to each other. Accordingly, there is no need to provide a space for arranging screws in the left-right direction between the motor and the rotating mechanism portion. In addition, compared to the case where different screws are used to fix the motor housing portion for accommodating the motor and the rotating mechanism housing, and to fix the motor inside the motor housing portion, the space for arranging the screws can be reduced. As a result, the increase in the overall length of the power tool caused by the screws for fixing the housing can be suppressed. In addition, the number of parts of the power tool can be reduced and the weight can be reduced.

[0048] In one or more embodiments, the motor may include a rotor that rotates about a rotation axis and a stator disposed around the rotor. The outer periphery of the stator may be clamped between the motor housing and the rotating mechanism housing by screws.

[0049] According to the above configuration, the motor housing portion, the rotating mechanism case, and the stator can be collectively fixed together using the same screw members.

[0050] In one or more embodiments, the stator may include a stator core, an insulator formed of an electrical insulating member, and a coil disposed on the stator via the insulator. The stator core may be clamped between the motor housing and the rotating mechanism housing by screws.

[0051] According to the above structure, the stator core in the stator can be fixed to the motor housing and the rotating mechanism housing together with the screw members. The stator core is composed of a laminated body of steel plates and has high rigidity. Therefore, by clamping the stator core, the stator can be firmly fixed.

[0052] In one or more embodiments, the stator may include a stator core, an insulator formed of an electrically insulating member, and a coil disposed on the stator via the insulator. The insulator may be clamped between the motor housing and the rotating mechanism housing by screws.

[0053] According to the above configuration, the insulator in the stator can be fixed to the motor housing and the rotating mechanism housing together with the screw members. For example, unlike the case where a separate member for being clamped by the screw members is provided on the stator, the number of parts does not increase, thereby reducing the number of parts and weight of the power tool.

[0054] In one or more embodiments, the insulator may include a front insulator disposed at the front of the stator core and a rear insulator disposed at the rear of the stator core. Either the front insulator or the rear insulator may be clamped between the motor housing and the rotating mechanism housing by a screw member.

[0055] According to the above configuration, the screw member can clamp one of the front and rear insulators without clamping the other, thereby reducing the influence of dimensional tolerance compared to the case of clamping both the front and rear insulators.

[0056] In one or more embodiments, the electric tool may further include a bearing holding member having a rotor bearing for rotatably supporting the rotor. The stator may be fixed between the motor housing and the rotating mechanism housing together with the bearing holding member by screws.

[0057] According to the above configuration, not only the stator but also the bearing holding member can be fixed together with the motor housing and the rotating mechanism housing by the same screw member. This can more effectively reduce the number of parts and weight of the electric tool.

[0058] In one or more embodiments, the outer peripheral portion of the stator and the bearing holding member may be fixed by being sandwiched between the motor housing portion and the rotating mechanism case.

[0059] According to the above configuration, the outer peripheral portion of the stator and the bearing holding member are sandwiched and fixed by the motor housing and the rotating mechanism case, and the rotor can be rotatably supported by the rotor bearing of the bearing holding member.

[0060] In one or more embodiments, the bearing holding member may include a boss portion extending in the axial direction and through which the screw member is inserted. The outer periphery of the stator may be sandwiched between the motor housing portion and the end surface of the boss portion.

[0061] According to the above configuration, by providing the boss portion on the bearing holding member, the axial force of the screw member can be effectively applied to the bearing holding member for fixing. In addition, the boss portion of the bearing holding member can be utilized as a contact portion for fixing the stator.

[0062] In one or more embodiments, the bearing holding member may include a rib protruding from the boss portion along the circumferential direction of the stator. The outer periphery of the stator may be in contact with the end surface of the boss portion and the end surface of the rib.

[0063] According to the above configuration, the ribs provided on the boss portion enhance the rigidity of the boss portion. Furthermore, by bringing the end faces of the boss portion and the ribs into contact with the outer periphery of the stator, the contact area between the bearing retaining member and the stator can be increased. Consequently, the stability of the screw-mounted fixing can be enhanced.

[0064] In one or more embodiments, the bearing retaining member may include a retaining plate portion that retains the rotor bearing, and a peripheral wall portion that rises from the outer periphery of the retaining plate portion and has a boss portion formed thereon. The power tool may further include a fan that rotates together with the rotor within a space enclosed by the motor, the retaining plate portion, and the peripheral wall portion.

[0065] With this configuration, the end surface of the boss portion on the peripheral wall contacts the stator, allowing the boss portion to function as a spacer, creating a gap between the motor (rotor and stator) and the retaining plate portion of the bearing retaining member. By arranging the fan in the resulting space, the motor can be efficiently cooled without the need for separate spacers to adjust the position of the components.

[0066] In one or more embodiments, the screw member may pass through a position radially outward of the outer peripheral surface of the stator core.

[0067] According to the above configuration, the screw member and the stator can be kept in contact with each other without providing a special structure between them. This prevents the stator core and the screw member from contacting each other during assembly or operation of the power tool, thereby preventing wear or peeling of the steel plate.

[0068] In one or more embodiments, the bearing holding member may be made of metal or resin.

[0069] According to the above configuration, for example, when a metal bearing retaining member is used, high mechanical strength or high rigidity can be easily obtained. When a resin bearing retaining member is used, it can be easily formed into a shape suitable for being fixed between the motor housing and the rotating mechanism housing by screw members.

[0070] In one or more embodiments, the plurality of screw members may be arranged to surround the motor in the rotational direction.

[0071] According to the above configuration, the motor can be firmly fixed without separately providing dedicated screws for fixing the motor inside the motor housing portion.

[0072] In one or more embodiments, the rotating mechanism housing may be made of metal. A threaded hole for mounting a screw member may be formed at the rear end of the rotating mechanism housing.

[0073] According to the above configuration, since a metal housing having high mechanical strength and rigidity can be used as the rotating mechanism housing, the motor housing portion and the motor can be stably fixed. In addition, for example, there is no need to form a structure in which a metal nut member or the like is embedded only in the threaded hole portion, and the threaded hole can be directly formed in the rotating mechanism housing.

[0074] In one or more embodiments, the impact tool may include: a motor; a motor housing portion that houses the motor; a rotating mechanism portion that includes a hammer disposed forward of the motor and rotated about a rotation axis by the motor, and an anvil that is struck in the rotational direction by the hammer; a rotating mechanism housing disposed forward of the motor housing portion and housing at least a portion of the rotating mechanism portion; and a screw member that extends from the rear of the motor housing portion to the rotating mechanism housing and secures the motor housing portion and the rotating mechanism housing to each other. At least a portion of the motor may be secured to the motor housing portion and the rotating mechanism housing together by the screw member.

[0075] According to the above-mentioned structure, the motor in the motor housing portion is fixed together with the motor housing portion and the rotating mechanism housing by using screw components in the front-to-back direction to fix the motor housing portion and the rotating mechanism housing to each other. Accordingly, there is no need to provide a space for arranging screws in the left-right direction between the motor and the rotating mechanism portion. In addition, compared to the case where different screws are used to fix the motor housing portion for accommodating the motor and the rotating mechanism housing, and to fix the motor inside the motor housing portion, the space for arranging the screws can be reduced. As a result, the increase in the total length of the impact tool caused by the screws for fixing the housing can be suppressed. In addition, the number of parts of the impact tool can be reduced and the weight can be reduced.

[0076] The following describes an embodiment with reference to the accompanying drawings. In the embodiment, the terms front, rear, left, right, top, and bottom are used to describe the positional relationships of various components. These terms represent relative positions or directions relative to the center of the power tool 1. The power tool 1 includes a motor 6 as a power source.

[0077] In the embodiment, a direction parallel to the rotation axis AX of the motor 6 is appropriately referred to as an axial direction, a direction around the rotation axis AX is appropriately referred to as a circumferential direction or a rotational direction, and a direction radial from the rotation axis AX is appropriately referred to as a radial direction.

[0078] The rotation axis AX extends along the front-to-back direction. One axial side is the front, and the other axial side is the rear. Furthermore, in the radial direction, a position closer to the rotation axis AX or in a direction close to the rotation axis AX is referred to as the radially inner side, while a position farther from the rotation axis AX or in a direction away from the rotation axis AX is referred to as the radially outer side.

[0079] [Power Tools]

[0080] Figure 1 It is a perspective view showing the electric tool 1 according to the embodiment as viewed from the front. Figure 2 It is a side view showing the electric tool 1 according to the embodiment. Figure 3 It is a longitudinal sectional view showing the electric power tool 1 according to the embodiment. Figure 4 It is a longitudinal sectional view showing the upper portion of the electric tool 1 according to the embodiment. Figure 5 It is a transverse cross-sectional view showing an upper portion of the electric tool 1 according to the embodiment. Figure 6 It is an exploded perspective view showing the electric tool 1 according to the embodiment.

[0081] The power tool 1 is a rotary tool whose output unit is rotated by a motor 6. In an embodiment, the power tool 1 is a screw-fastening tool that tightens fasteners such as screws, bolts, and nuts by rotating the output unit. The power tool 1 may also be an electric drill that performs drilling operations by rotating the output unit. In an embodiment, the power tool 1 is an impact tool, which is a type of screw-fastening tool. As an example of an impact tool, the power tool 1 is an impact driver.

[0082] The power tool 1 includes a housing 2, a rotating mechanism 3, a hammer housing (rotating mechanism housing) 4, and a motor 6. The rotating mechanism 3 includes a speed reduction mechanism 7, a spindle 8, a striking mechanism 9, and an anvil (output unit) 10. The power tool 1 also includes a tool holding mechanism 11, a fan 12, a battery mounting portion 13, a trigger shifter 14, a forward / reverse switching shifter 15, an operation display 16, a mode switching switch 17, and a light unit 18.

[0083] The housing 2 is made of synthetic resin. In the embodiment, the housing 2 is made of nylon. The housing 2 includes a left housing 2L and a right housing 2R positioned to the right of the left housing 2L. The left housing 2L and the right housing 2R are fixed together by a plurality of screws 2S.

[0084] The housing 2 includes a rear housing 2B disposed behind the left housing 2L and the right housing 2R. The rear housing 2B is fixed to the hammer housing 4, the left housing 2L, and the right housing 2R.

[0085] The housing 2 includes a motor housing portion 21 , a grip portion 22 , a battery holding portion 23 , and a case holding portion 24 .

[0086] The motor housing portion 21 houses the motor 6. The motor housing portion 21 has a peripheral surface portion 21A surrounding the outer periphery of the motor 6, and a rear surface portion 21B covering the rear of the motor 6. The motor housing portion 21 is provided in the rear housing 2B. The peripheral surface portion 21A is formed by the outer periphery of the rear housing 2B, and the rear surface portion 21B is formed by the rear surface portion of the rear housing 2B. The motor 6 is arranged on the inner periphery of the motor housing portion 21, that is, on the inner periphery of the rear housing 2B. The motor housing portion 21 houses at least a portion of the fan 12. The fan 12 is arranged on the inner periphery of the motor housing portion 21. The motor housing portion 21 houses at least a portion of the bearing retaining component 5. The bearing retaining component 5 is arranged on the inner periphery of the motor housing portion 21. The bearing retaining component 5 is arranged in the opening of the front end portion of the motor housing portion 21.

[0087] The housing holder 24 is cylindrical. It accommodates at least a portion of the hammer case 4. The front and rear surfaces of the housing holder 24 are open. The housing holder 24 covers the periphery of the hammer case 4 so that the anvil 10 protrudes forward. A portion of the hammer case 4 protrudes forward from the front opening of the housing holder 24.

[0088] The grip 22 is connected to the housing holder 24. In the embodiment, the grip 22 extends downward from the housing holder 24. Furthermore, the grip 22 is connected to the motor housing 21. The grip 22 extends downward from the motor housing 21. The trigger shifter 14 and the forward / reverse switching shifter 15 are provided on the upper portion of the grip 22. The grip 22 is grasped by the operator.

[0089] The battery holding portion 23 is connected to the lower end of the grip portion 22. The outer dimensions of the battery holding portion 23 in the front-back direction and the left-right direction are larger than the outer dimensions of the grip portion 22. The battery holding portion 23 allows the battery pack 25 to be attached and detached.

[0090] The grip portion 22 and the battery holding portion 23 have a half-split structure and are provided in the left housing 2L and the right housing 2R, respectively.

[0091] The rear housing 2B is made of synthetic resin. It is positioned behind the housing holder 24. The rear housing 2B is positioned behind the hammer case 4. The rear housing 2B covers the opening at the rear end of the cylindrical housing holder 24. The front end of the rear housing 2B and the rear end of the housing holder 24 face each other in a front-to-back relationship. The rear housing 2B is secured to the rear end of the hammer case 4 with four screws 4S.

[0092] The rear case 2B has an air inlet 19 and an air outlet 20. Air outside the housing 2 flows into the interior of the housing 2 through the air inlet 19. Air inside the housing 2 flows out to the exterior of the housing 2 through the air outlet 20.

[0093] The hammer case 4 is made of metal. In the embodiment, it is made of aluminum. It has a cylindrical shape and is located in front of the motor housing 21. It is located on the inner circumference of the housing retaining portion 24. The hammer case 4 is configured to fit within the opening at the front end of the rear housing 2B. The hammer case 4 is connected to the rear housing 2B. The hammer case 4 is secured to the front end of the rear housing 2B by four screw members 4S. The hammer case 4 has four bosses 4H formed with threaded holes for the screw members 4S to fit into.

[0094] A bearing retaining member 5 is disposed at the rear of the hammer case 4. The outer periphery of the bearing retaining member 5 fits into the opening at the rear end of the hammer case 4. The bearing retaining member 5 is fixed to the rear case 2B and the hammer case 4. The bearing retaining member 5 is secured between the rear case 2B and the hammer case 4 by screws 4S. The bearing retaining member 5 retains the spindle bearing 44 that supports the spindle 8. The bearing retaining member 5 retains the rotor bearing 39F that supports the rotor shaft 33 via the spindle 8. The bearing retaining member 5 is made of metal or resin. In the embodiment, the bearing retaining member 5 is made of metal, specifically aluminum.

[0095] The hammer case 4 is a rotating mechanism case that houses at least a portion of the rotating mechanism portion 3. The hammer case 4 houses at least a portion of the speed reduction mechanism 7, the spindle 8, the striking mechanism 9, and the anvil 10.

[0096] The hammer case 4 includes a first cylindrical portion 4A and a second cylindrical portion 4B. The first cylindrical portion 4A is disposed around the striking mechanism 9. The second cylindrical portion 4B is disposed further forward than the first cylindrical portion 4A. The outer diameter of the second cylindrical portion 4B is smaller than that of the first cylindrical portion 4A.

[0097] At least a portion of the surface of the hammer case 4 is covered by the case holding portion 24. At least a portion of the surface of the hammer case 4 is covered by the hammer case cover 85. The case holding portion 24 and the hammer case cover 85 protect the hammer case 4. The case holding portion 24 and the hammer case cover 85 can prevent contact between the hammer case 4 and surrounding objects. In the embodiment, substantially the entire surface of the hammer case 4 is covered by the case holding portion 24 and the hammer case cover 85.

[0098] The motor 6 is the power source of the power tool 1. It is an inner rotor brushless motor. It includes a stator 26 and a rotor 27. The stator 26 is supported by the motor housing 21. The stator 26 is positioned around the rotor 27. The rotor 27 rotates relative to the stator 26. The rotor 27 rotates about a rotation axis AX extending in the front-to-back direction.

[0099] The stator 26 includes a stator core 28, an insulator, and a coil 31. The insulator includes a front insulator 29 and a rear insulator 30. The stator 26 is connected to a power line 26L (see FIG. 26 ) that supplies power to the coil 31. Figure 11 The stator 26 is connected to the controller 38 via the power line 26L (see Figure 3 ).

[0100] Stator core 28 is positioned radially outward from rotor 27. Stator core 28 is composed of multiple stacked steel plates. Steel plates are metal plates primarily composed of iron. Stator core 28 is annular and has multiple teeth that support coils 31.

[0101] Insulators are interposed between the stator core 28 and the coils 31. A front insulator 29 is located at the front of the stator core 28. A rear insulator 30 is located at the rear of the stator core 28. Both the front insulator 29 and the rear insulator 30 are electrically insulating components made of synthetic resin. The front insulator 29 is positioned to partially cover the surface of the teeth. The rear insulator 30 is positioned to partially cover the surface of the teeth.

[0102] Coil 31 is attached to stator core 28 via front insulator 29 and rear insulator 30. Multiple coils 31 are provided. Coil 31 is arranged around the teeth of stator core 28 via front insulator 29 and rear insulator 30. Coil 31 is electrically insulated from stator core 28 by front insulator 29 and rear insulator 30.

[0103] The rotor 27 rotates around the rotation axis AX and includes a rotor core portion 32 and a rotor shaft portion 33 .

[0104] The rotor core 32 and rotor shaft 33 are each made of steel. The rotor shaft 33 protrudes in the front-to-back direction from the end surface of the rotor core 32. The rotor shaft 33 includes a front shaft portion 33F protruding forward from the front end surface of the rotor core 32 and a rear shaft portion 33R protruding rearward from the rear end surface of the rotor core 32.

[0105] The rotor core portion 32 includes a rotor magnet (not shown). The rotor magnet extends in the axial direction from the front surface to the rear surface of the rotor core portion 32. The rotor magnet is arranged inside the rotor core portion 32.

[0106] A sensor substrate 37 is mounted on the rear insulator 30. The sensor substrate 37 is fixed to the rear insulator 30 by screws 37S. Figure 11 As shown, the sensor substrate 37 includes a circuit substrate 37A and a rotation detection element 37B supported by the circuit substrate 37A. The circuit substrate 37A and the rotation detection element 37B are covered with a bulk molding compound 37C. A signal line 37L is connected to the sensor substrate 37. The sensor substrate 37 is connected to the controller 38 (see FIG. 1 ) via the signal line 37L. Figure 3 At least a portion of the sensor substrate 37 faces the rear end surface of the rotor core portion 32. The rotation detection element 37B detects the position of the rotor magnet to thereby detect the position of the rotor 27 in the rotational direction.

[0107] The rotor shaft portion 33 is supported by a rotor bearing. The rotor bearing includes a front rotor bearing 39F that rotatably supports the front shaft portion 33F, and a rear rotor bearing 39R that rotatably supports the rear shaft portion 33R. Rotor bearings 39F and 39R rotatably support the rotor 27.

[0108] The rotor bearing 39R is held by the rear housing 2B. The rotor bearing 39F is held by the main shaft 8. The front end of the rotor shaft 33 passes through the rotor bearing 39F and is disposed within the interior space of the hammer case 4. The front end of the rotor shaft 33 is connected to the rotating mechanism 3 within the hammer case 4.

[0109] As described above, the rotating mechanism 3 includes the speed reduction mechanism 7, the main shaft 8, the striking mechanism 9, and the anvil 10. The speed reduction mechanism 7 is positioned forward of the motor 6. A pinion 41 is formed at the front end of the rotor shaft 33. The pinion 41 is coupled to at least a portion of the speed reduction mechanism 7. The rotor shaft 33 is coupled to the speed reduction mechanism 7 via the pinion 41.

[0110] The speed reduction mechanism 7 is disposed on the front surface side of the bearing retaining member 5. The speed reduction mechanism 7 is disposed inside the hammer case 4. The speed reduction mechanism 7 connects the rotor shaft 33 and the main shaft 8. The speed reduction mechanism 7 transmits the rotation of the rotor 27 to the main shaft 8. The speed reduction mechanism 7 rotates the main shaft 8 at a speed lower than the rotation speed of the rotor shaft 33. The speed reduction mechanism 7 includes a planetary gear mechanism.

[0111] The speed reduction mechanism 7 includes a plurality of gears, and the gears of the speed reduction mechanism 7 are driven by the rotor 27 .

[0112] The speed reduction mechanism 7 includes a plurality of planetary gears 42 arranged around a pinion gear 41, and an internal gear 43 arranged around the plurality of planetary gears 42. The pinion gears 41, the planetary gears 42, and the internal gear 43 are each housed in the hammer case 4. The plurality of planetary gears 42 mesh with the pinion gears 41. The planetary gears 42 are rotatably supported on the main shaft 8 via pins 42P. The main shaft 8 is rotated by the planetary gears 42. The internal gear 43 has internal teeth that mesh with the planetary gears 42. The internal gear 43 is fixed to the hammer case 4. A stepped portion is provided on the rear portion of the inner circumferential surface of the hammer case 4 for the internal gear 43 to be positioned. The internal gear 43 is positioned between the wall of the stepped portion and the bearing retaining member 5. The internal gear 43 cannot always rotate relative to the hammer case 4.

[0113] When the motor 6 is driven to rotate the rotor shaft 33, the pinion gear 41 rotates, causing the planetary gear 42 to orbit around the pinion gear 41. The planetary gear 42 orbits while meshing with the internal teeth of the internal gear 43. The orbital rotation of the planetary gear 42 causes the main shaft 8, which is connected to the planetary gear 42 via the pin 42P, to rotate at a speed lower than the rotation speed of the rotor shaft 33.

[0114] The spindle 8 is positioned forward of at least a portion of the motor 6. The spindle 8 is positioned forward of the stator 26. At least a portion of the spindle 8 is positioned forward of the rotor 27. At least a portion of the spindle 8 is positioned forward of the speed reduction mechanism 7. The spindle 8 is positioned rearward of the anvil 10.

[0115] The spindle 8 is a rotating member rotated by the rotor 27. The spindle 8 is rotated by the rotational force of the rotor 27 transmitted by the speed reduction mechanism 7. The spindle 8 transmits the rotational force of the motor 6 to the anvil 10 via the balls 48 and the hammer 47.

[0116] The main shaft 8 includes a flange portion 8A, a shaft portion 8B protruding forward from the flange portion 8A, and a retaining portion 8C. The flange portion 8A rotatably supports the planetary gear 42 via a pin 42P. The rotation axis of the main shaft 8 coincides with the rotation axis AX of the motor 6. The main shaft 8 rotates around the rotation axis AX. A retaining portion 8C is provided at the rear end portion of the main shaft 8. The retaining portion 8C protrudes rearward from the flange portion 8A. The retaining portion 8C has a cylindrical shape. The retaining portion 8C is surrounded by the main shaft bearing 44. The main shaft 8 is rotatably supported by the main shaft bearing 44.

[0117] The bearing retaining member 5 is disposed around at least a portion of the spindle 8. The bearing retaining member 5 has an annular shape. The bearing retaining member 5 retains the spindle bearing 44. The spindle bearing 44 is retained on the inner circumferential surface of the bearing retaining member 5. The inner circumferential surface of the spindle bearing 44 is in contact with and supports the spindle 8.

[0118] The striking mechanism 9 is driven by the motor 6. The rotational force of the motor 6 is transmitted to the striking mechanism 9 via the speed reduction mechanism 7 and the main shaft 8. The striking mechanism 9 strikes the anvil 10 in the rotational direction based on the rotational force of the main shaft 8 rotated by the motor 6. The striking mechanism 9 includes a hammer 47, a ball 48, a coil spring 49, and a washer 50. The striking mechanism 9, including the hammer 47, the ball 48, the coil spring 49, and the washer 50, is housed in the first cylindrical portion 4A of the hammer case 4.

[0119] The hammer 47 is positioned forward of the speed reduction mechanism 7. It is positioned around the spindle 8 and retained by the spindle 8. The ball 48 is positioned between the spindle 8 and the hammer 47. The hammer 47 includes a cylindrical hammer body 47D and a hammer protrusion 47E located forward of the hammer body 47D. An annular recess 47C is provided on the rear surface of the hammer body 47D. The recess 47C extends forward from the rear surface of the hammer body 47D.

[0120] The hammer 47 is arranged around the shaft portion 8B of the main shaft 8. The hammer 47 has a hole 47A for arranging the shaft portion 8B.

[0121] The hammer 47 is rotated by the motor 6. The rotational force of the motor 6 is transmitted to the hammer 47 via the speed reduction mechanism 7 and the main shaft 8. The hammer 47 is rotated by the main shaft 8. In other words, the hammer 47 can rotate together with the main shaft 8 based on the rotational force of the main shaft 8 rotated by the motor 6. The rotation axis of the hammer 47, the rotation axis of the main shaft 8, and the rotation axis AX of the motor 6 are aligned. The hammer 47 rotates around the rotation axis AX.

[0122] The washer 50 is arranged inside the recess 47C and supported by the hammer 47 via a plurality of balls 51. The balls 51 are arranged forward of the washer 50. The washer 50 and the hammer 47 are relatively movable in the rotational direction by the balls 51.

[0123] Coil spring 49 is disposed around shaft 8B. The rear end of coil spring 49 is supported by flange 8A. The front end of coil spring 49 is disposed inside recess 47C and supported by washer 50. Coil spring 49 constantly generates a biasing force (elastic force) to move hammer 47 forward.

[0124] Ball 48 is made of metal such as steel. Ball 48 is positioned between shaft 8B and hammer 47. Spindle 8 has a spindle groove 8D for accommodating at least a portion of ball 48. Spindle groove 8D is provided on a portion of the outer circumferential surface of shaft 8B. Hammer 47 has a hammer groove 47B for accommodating at least a portion of ball 48. Hammer groove 47B is provided on a portion of the inner surface of hammer 47. Ball 48 is positioned between spindle groove 8D and hammer groove 47B. Ball 48 can roll inside spindle groove 8D and hammer groove 47B, respectively. Hammer 47 can move with ball 48. Spindle 8 and hammer 47 are capable of relative movement in the axial and rotational directions within the movable ranges defined by spindle groove 8D and hammer groove 47B.

[0125] Anvil 10 is positioned further forward than motor 6. Anvil 10 is the output portion of power tool 1, rotating based on the rotational force of rotor 27. At least a portion of anvil 10 is positioned further forward than hammer 47. Anvil 10 has a tool hole 10A for inserting a tip tool. Tool hole 10A is provided at the front end of anvil 10. The tip tool is mounted on anvil 10.

[0126] The anvil 10 has an anvil convex portion 10B. The anvil convex portion 10B is provided at the rear end portion of the anvil 10. The anvil convex portion 10B protrudes rearward from the rear end portion of the anvil 10. The main shaft 8 is arranged at the rear of the anvil 10. The main shaft recess 8E is provided at the front end portion of the shaft portion 8B. The anvil convex portion 10B is arranged in the main shaft recess 8E. The main shaft recess 8E is recessed from the front end surface of the shaft portion 8B toward the rear and receives the anvil convex portion 10B.

[0127] The anvil 10 includes a rod-shaped anvil shaft portion 10C and an anvil protrusion portion 10D. A tool hole 10A is provided at the front end portion of the anvil shaft portion 10C. A front end tool is mounted on the anvil shaft portion 10C. The anvil protrusion portion 10D is provided at the rear end portion of the anvil 10. The anvil protrusion portion 10D protrudes radially outward from the rear end portion of the anvil shaft portion 10C.

[0128] The anvil 10 is rotatably supported by a bearing 46. The rotation axis of the anvil 10, the rotation axis of the hammer 47, the rotation axis of the spindle 8, and the rotation axis AX of the motor 6 are aligned. The anvil 10 rotates about the rotation axis AX. The bearing 46 is arranged around the anvil shaft portion 10C. The bearing 46 is arranged inside the second cylindrical portion 4B of the hammer case 4. The bearing 46 is retained by the second cylindrical portion 4B of the hammer case 4. The bearing 46 rotatably supports the anvil shaft portion 10C.

[0129] An O-ring 45 is disposed between the bearing 46 and the anvil shaft portion 10C. The O-ring 45 is in contact with the outer peripheral portion of the anvil shaft portion 10C and the inner peripheral portion of the bearing 46, respectively.

[0130] Two bearings 46 are arranged in the axial direction. These bearings 46 are ball bearings. They include an inner ring, balls, and an outer ring. The inner ring of bearing 46 contacts O-ring 45. The balls of bearing 46 are radially positioned between the inner and outer rings. The balls of bearing 46 contact the inner and outer rings, respectively. Multiple balls of bearing 46 are circumferentially arranged. The outer ring is positioned radially outward of the inner ring and balls. The outer ring of bearing 46 contacts the inner circumferential surface of the second cylindrical portion 4B.

[0131] At least a portion of hammer 47 is capable of contacting anvil protrusion 10D. A hammer protrusion 47E protruding forward is provided at the front of hammer 47. Hammer protrusion 47E is capable of contacting anvil protrusion 10D. While hammer 47 is in contact with anvil protrusion 10D, motor 6 drives anvil 10, hammer 47, and spindle 8, rotating together.

[0132] The anvil 10 is struck in the rotational direction by the hammer 47. For example, during a screw tightening operation, when the load acting on the anvil 10 increases, a situation may arise where the load of the coil spring 49 alone cannot rotate the anvil 10. When the load of the coil spring 49 alone cannot rotate the anvil 10, the rotation of the anvil 10 and the hammer 47 stops. The spindle 8 and the hammer 47 are capable of relative movement in the axial and circumferential directions, respectively, by means of the ball bearings 48. Even when the hammer 47 stops rotating, the spindle 8 continues to rotate, driven by the power generated by the motor 6. When the hammer 47 stops rotating, the spindle 8 rotates, and the ball bearings 48 move rearward while being guided by the spindle groove 8D and the hammer groove 47B. The hammer 47 receives force from the ball bearings 48, and moves rearward along with the ball bearings 48. That is, when the anvil 10 is stopped, the hammer 47 is moved rearward by the rotation of the spindle 8. The rearward movement of the hammer 47 releases the contact between the hammer 47 and the anvil protrusion 10D.

[0133] As described above, the coil spring 49 constantly generates a force to move the hammer 47 forward. The hammer 47, having moved backward, is moved forward by the force of the coil spring 49. As it moves forward, the hammer 47 receives a rotational force from the ball bearing 48. In other words, the hammer 47 rotates while moving forward. As the hammer 47 rotates while moving forward, it contacts the anvil protrusion 10D while rotating. Consequently, the anvil protrusion 10D is struck in the rotational direction by the hammer protrusion 47E of the hammer 47. Both the power of the motor 6 and the inertial force of the hammer 47 act on the anvil 10. Consequently, the anvil 10 can rotate about the rotation axis AX with a high torque.

[0134] The tool holding mechanism 11 is disposed around the front portion of the anvil 10. The tool holding mechanism 11 holds a tip tool inserted into the tool hole 10A of the anvil 10. The tool holding mechanism 11 is capable of attaching and detaching the tip tool.

[0135] The tool holding mechanism 11 includes a ball 71 , a leaf spring 72 , a sleeve 73 , a coil spring 74 , a positioning member 75 , a ring spring 77 , and a washer 78 .

[0136] The anvil 10 has a support recess 76 for supporting the ball 71. The support recess 76 is formed on the outer peripheral surface of the anvil shaft portion 10C. Two support recesses 76 are formed on the anvil shaft portion 10C.

[0137] The ball 71 is movably supported by the anvil 10. The ball 71 is arranged in the support recess 76. One ball 71 is arranged in one support recess 76.

[0138] Anvil shaft portion 10C includes a through-hole connecting the inner surface of support recess 76 to the inner surface of tool hole 10A. When ball 71 is supported by support recess 76, at least a portion of ball 71 is positioned inside tool hole 10A. Ball 71 secures a tip tool inserted into tool hole 10A. Ball 71 is movable between an engaged position, which secures the tip tool, and a released position, which releases the tool from being secured.

[0139] The leaf spring 72 generates an elastic force for moving the ball 71 toward the engagement position. The leaf spring 72 is disposed around the anvil shaft portion 10C. The leaf spring 72 generates an elastic force for moving the ball 71 radially inward.

[0140] Sleeve 73 is a cylindrical component. It is positioned around anvil shaft 10C. Sleeve 73 is axially movable around anvil shaft 10C. Sleeve 73 prevents ball 71, positioned in the engaged position, from disengaging from the engaged position. By moving axially, sleeve 73 causes ball 71 to shift from the engaged position to the released position.

[0141] The sleeve 73 is movable around the anvil shaft portion 10C between a blocking position for blocking the balls 71 from moving radially outward and a allowing position for allowing the balls 71 to move radially outward.

[0142] By positioning the sleeve 73 in the blocking position, the ball 71 positioned in the engaged position can be prevented from moving radially outward. In other words, by positioning the sleeve 73 in the blocking position, the ball 71 positioned in the engaged position can be prevented from disengaging from the engaged position. By positioning the sleeve 73 in the blocking position, the tip tool can be maintained in a state secured by the ball 71.

[0143] By moving the sleeve 73 to the permitted position, the ball 71 positioned in the engaged position is permitted to move radially outward. By moving the sleeve 73 to the permitted position, the ball 71 is enabled to move from the engaged position to the released position. In other words, by positioning the sleeve 73 in the permitted position, the ball 71 positioned in the engaged position is permitted to disengage from the engaged position. By positioning the sleeve 73 in the permitted position, the state in which the tip tool is secured by the ball 71 can be released.

[0144] The coil spring 74 generates an elastic force to move the sleeve 73 toward the blocking position. The coil spring 74 is arranged around the anvil shaft portion 10C. The blocking position is defined as a position further rearward than the permitted position. The coil spring 74 generates an elastic force for moving the sleeve 73 toward the rear. The front end portion of the coil spring 74 contacts the washer 78. The washer 78 is supported from the front by the annular spring 77 assembled on the anvil shaft portion 10C. Accordingly, the coil spring 74 is supported by the annular spring 77 via the washer 78, and applies force to the sleeve 73 toward the rear.

[0145] The positioning member 75 is an annular member fixed to the outer peripheral surface of the anvil shaft portion 10C. The positioning member 75 is fixed at a position where it can be opposed to the rear end of the sleeve 73. The positioning member 75 positions the sleeve 73 in the blocking position. The sleeve 73, which is given a rearward elastic force by the coil spring 74, is positioned in the blocking position by contact with the positioning member 75.

[0146] Fan 12 is positioned forward of stator 26 of motor 6. Fan 12 generates airflow for cooling motor 6. Fan 12 is fixed to at least a portion of rotor 27. Fan 12 is fixed to front shaft portion 33F. Fan 12 is positioned between rotor bearing 39F and stator 26.

[0147] The fan 12 rotates due to the rotation of the rotor 27. The fan 12 rotates along with the rotor shaft 33 as the rotor shaft 33 rotates. The rotation of the fan 12 causes air from the exterior of the housing 2 to flow into the interior of the housing 2 through the air inlet 19. The air flowing into the interior of the housing 2 circulates within the interior of the housing 2, cooling the motor 6. The air circulating within the interior of the housing 2 is rotated by the fan 12 and is then sent radially outward from the fan 12. The air sent by the fan 12 flows within the housing 2 through the exhaust port 20 and out to the exterior of the housing 2.

[0148] The battery mounting portion 13 is located below the battery holding portion 23. The battery mounting portion 13 is connected to a battery pack 25. The battery pack 25 is mounted in the battery mounting portion 13. In the embodiment, there is a single battery mounting portion 13. One battery pack 25 is mounted in the battery mounting portion 13. The battery pack 25 is attachable to and detachable from the battery mounting portion 13. The battery pack 25 is attached to the battery mounting portion 13 by inserting it from the front of the battery holding portion 23 into the battery mounting portion 13. The battery pack 25 is removed from the battery mounting portion 13 by pulling it forward from the battery mounting portion 13. The battery pack 25 includes a secondary battery. In the embodiment, the battery pack 25 includes a rechargeable lithium-ion battery. When mounted in the battery mounting portion 13, the battery pack 25 can supply power to the power tool 1. The motor 6 is driven by the power supplied from the battery pack 25. The operation display unit 16 operates with the power supplied from the battery pack 25 .

[0149] The rated voltage of the battery pack 25 is not particularly limited. For example, the rated voltage of the battery pack 25 is 18V or higher. The rated voltage of the battery pack 25 can be 18V, 36V, or 72V. Alternatively, the rated voltage of the battery pack 25 can be less than 18V, such as 10.8V or 14.4V.

[0150] The trigger paddle 14 is provided at the front portion of the grip portion 22. The trigger paddle 14 is operated by the operator to start the motor 6. By operating the trigger paddle 14, the driving and stopping of the motor 6 are switched.

[0151] The forward / reverse switching lever 15 is located above the grip 22. The operator operates the forward / reverse switching lever 15 to switch the rotational direction of the motor 6. By operating the forward / reverse switching lever 15, the rotational direction of the motor 6 is switched from one of the forward and reverse directions to the other. By switching the rotational direction of the motor 6, the rotational direction of the spindle 8 is also switched.

[0152] The operation display unit 16 is provided on the battery holder 23. It is located on the upper surface of the battery holder 23, further forward than the grip 22. The operation display unit 16 includes a plurality of operation buttons 16A. The operator switches the operating mode of the motor 6 by operating the operation buttons 16A. The operation display unit 16 can also be located further rearward than the grip 22, for example, on the rear surface of the battery holder 23.

[0153] The mode changeover switch 17 is provided on the upper portion of the trigger paddle 14. The mode changeover switch 17 is operated by an operator to switch the operation mode of the motor 6.

[0154] Figure 7 1 is an exploded perspective view showing the lamp assembly 18 involved in the embodiment. The lamp assembly 18 emits illumination light. The lamp assembly 18 illuminates the anvil 10 and the periphery of the anvil 10 with the illumination light. The lamp assembly 18 illuminates the front of the anvil 10 with the illumination light. In addition, the lamp assembly 18 illuminates the front end tool assembled on the anvil 10 and the periphery of the front end tool with the illumination light. In the embodiment, the lamp assembly 18 includes: an annular lamp housing 18A, a plurality of light emitting elements 18B (refer to Figure 5 ), and a lampshade 18C covering the outer circumference of the lamp housing 18A. The lamp housing 18A is disposed around the second cylindrical portion 4B of the hammer housing 4. An engaging rib 18D is formed on the inner circumference of the lamp housing 18A. The engaging ribs 18D extend circumferentially along the inner circumference of the lamp housing 18A. A plurality of engaging ribs 18D are formed on the inner circumference of the lamp housing 18A. Engaging protrusions 4E that engage with the engaging ribs 18D are formed on the outer circumference of the second cylindrical portion 4B. The engaging protrusions 4E extend circumferentially along the outer circumference of the second cylindrical portion 4B. The number of engaging protrusions 4E provided is the same as the number of engaging ribs 18D.

[0155] When installing the lamp assembly 18, the lamp assembly 18 is inserted into the outer periphery of the second cylindrical portion 4B from the front while adjusting the angle of the rotation direction so that the engaging rib 18D and the engaging protrusion 4E are non-contacting. Thereafter, the lamp assembly 18 is rotated around the second cylindrical portion 4B so that the engaging rib 18D is arranged behind the engaging protrusion 4E. Accordingly, the engaging rib 18D engages with the engaging protrusion 4E in the front-to-back direction, and the lamp assembly 18 is retained in the hammer housing 4. In addition, the lamp assembly 18 has an anti-detachment component 18E for preventing the lamp housing 18A from falling off from the second cylindrical portion 4B toward the front. The anti-detachment component 18E is assembled on the front surface side of the lamp housing 18A in the second cylindrical portion 4B (refer to Figure 5 ).

[0156] The hammer case cover 85 is annular and has an opening 85A at the front. The hammer case cover 85 is attached to the front portion of the hammer case 4 from the front side of the hammer case 4. The front portion of the hammer case 4 protrudes forward from the opening 85A. The hammer case cover 85 is positioned behind the lamp assembly 18. The lamp assembly 18 also functions as a retaining member that prevents the hammer case cover 85 from falling forward from the hammer case 4.

[0157] [Support structure of rotor shaft and main shaft]

[0158] Figure 8 It is a perspective view showing the bearing holding member 5 and the main shaft 8 according to the embodiment as seen from the rear. Figure 9 It is an exploded perspective view showing the support structure of the bearing and the main shaft 8 according to the embodiment as viewed from the front. Figure 10 It is an exploded perspective view showing the support structure of the bearing and the main shaft 8 according to the embodiment as viewed from the rear. Figure 11 It is a longitudinal sectional view showing the peripheral structure of the bearing holding member 5 according to the embodiment. Figure 12 It is an exploded perspective view showing the bearing holding member 5 and the hammer case 4 according to the embodiment as seen from the front. Figure 13 : is a sectional view showing the bearing holding member 5 according to the embodiment as viewed from the front. Figure 13 It shows the cross section orthogonal to the rotation axis AX.

[0159] In the embodiment, the main shaft bearing 44 holds the rotor bearing 39F via the main shaft 8 . The main shaft bearing 44 is held by the bearing holding member 5 .

[0160] The bearing holding member 5 has an annular shape and includes a flat plate-shaped holding plate portion 55 extending in the radial direction. Furthermore, the bearing holding member 5 includes a peripheral wall portion 56 extending from the outer periphery of the holding plate portion 55 in the axial direction.

[0161] The retaining plate portion 55 has an annular shape with a retaining opening 55A formed in the center. The retaining opening 55A has a circular shape and penetrates the retaining plate portion 55 in the front-to-back direction. The bearing retaining component 5 retains the main shaft bearing 44 in the retaining opening 55A. The front surface of the retaining plate portion 55 is opposite to the main shaft 8. The rear surface of the retaining plate portion 55 is opposite to the fan 12. A rib 58A, a first recess 58B, and a second recess 58C are formed on the front surface of the retaining plate portion 55. The rib 58A, the first recess 58B, and the second recess 58C have an annular shape surrounding the retaining opening 55A. The rib 58A protrudes forward from the front surface of the retaining plate portion 55. The first recess 58B is arranged at a position closer to the inner peripheral side than the rib 58A and is recessed from the front surface of the retaining plate portion 55 toward the rear. The second recess 58C is arranged further inward than the first recess 58B and is recessed further rearward than the first recess 58B. The inner peripheral edge of the second recess 58C serves as the edge of the holding opening 55A.

[0162] The peripheral wall portion 56 protrudes rearward from the outer periphery of the retaining plate portion 55. The peripheral wall portion 56 extends along the outer periphery of the retaining plate portion 55. The peripheral wall portion 56 is annular. A boss portion 5H is provided on the outer periphery of the peripheral wall portion 56. The boss portion 5H has an insertion hole formed therein for inserting the screw member 4S.

[0163] like Figure 11 As shown, the bearing holding member 5 is fitted from behind into the opening of the rear end portion of the first cylindrical portion 4A of the hammer case 4. A sealing member 65 is provided between the outer peripheral surface of the bearing holding member 5 and the inner peripheral surface of the hammer case 4. The sealing member 65 is an O-ring.

[0164] The main shaft bearing 44 has an annular shape. The main shaft bearing 44 is arranged on the inner peripheral surface of the retaining opening 55A. The main shaft bearing 44 is retained in the retaining opening 55A. The inner peripheral surface of the main shaft bearing 44 is in contact with the main shaft 8. The main shaft bearing 44 supports the outer peripheral surface of the main shaft 8. The main shaft bearing 44 includes a sliding bearing. Although the type of sliding bearing is not particularly limited, in the embodiment, the main shaft bearing 44 is a self-lubricating bearing (so-called oil-free bearing). Compared with rolling bearings such as ball bearings, sliding bearings have a simple structure and higher rigidity. The main shaft bearing 44 supports the main shaft 8 in the radial direction. The main shaft bearing 44 supports the main shaft 8 in the axial direction. The main shaft bearing 44 includes a radial bearing portion 44A and a thrust bearing portion 44B.

[0165] The radial bearing 44A radially supports the outer circumferential surface of the main shaft 8. The radial bearing 44A is positioned on the inner circumferential surface of the retaining opening 55A. The radial bearing 44A is annular. The outer circumferential surface of the radial bearing 44A contacts the inner surface of the retaining opening 55A. The inner circumferential surface of the radial bearing 44A contacts the outer circumferential surface of the main shaft 8. Specifically, the radial bearing 44A contacts the outer circumferential surface 81 of the retaining portion 8C of the main shaft 8. Thus, the main shaft bearing 44 supports the outer circumferential surface 81 of the retaining portion 8C of the main shaft 8.

[0166] The thrust bearing 44B supports the main shaft 8 in the axial direction. It extends radially from the axial end surface of the radial bearing 44A in a flange-like manner. It extends radially outward from the front end surface of the radial bearing 44A. The thrust bearing 44B extends along the front surface of the retaining plate 55. The rear surface of the thrust bearing 44B contacts the front surface of the retaining plate 55. The thrust bearing 44B serves as a positioning member for the main shaft bearing 44 in the front-to-back direction. The front surface of the thrust bearing 44B axially opposes the flange 8A of the main shaft 8. Sliding surfaces 44C are provided on the front surface of the thrust bearing 44B to axially support the rear surface of the flange 8A. Multiple sliding surfaces 44C are formed at equal intervals along the circumference of the thrust bearing 44B. These sliding surfaces 44C are cushion-shaped and extend circumferentially along the front surface of the thrust bearing 44B. Adjacent sliding surfaces 44C are partitioned by grooves 44D. Grooves 44D function as a reservoir for lubricant.

[0167] The main shaft 8 is arranged on the inner peripheral side of the main shaft bearing 44. The main shaft 8 is rotatably supported by the main shaft bearing 44.

[0168] The main shaft 8 includes a retaining portion 8C that holds the rotor bearing 39F. The retaining portion 8C has a cylindrical shape. The rotor bearing 39F and the rotor shaft portion 33 are disposed inside the retaining portion 8C. The retaining portion 8C protrudes rearward from the rear surface of the flange portion 8A. The central axis of the retaining portion 8C coincides with the rotation axis of the main shaft 8, i.e., the rotation axis AX of the motor 6.

[0169] The retaining portion 8C is arranged inside the retaining opening 55A of the bearing retaining component 5. The retaining portion 8C is arranged on the inner peripheral side of the main shaft bearing 44. The retaining portion 8C has a circular outer peripheral surface 81. The outer peripheral surface 81 of the retaining portion 8C is a sliding surface that contacts the main shaft bearing 44. The outer peripheral surface 81 of the retaining portion 8C contacts the inner peripheral surface of the radial bearing portion 44A. The rear surface of the flange portion 8A is a sliding surface that contacts the main shaft bearing 44. The rear surface of the flange portion 8A can contact the sliding surface 44C of the thrust bearing portion 44B. The main shaft bearing 44 supports the outer peripheral surface 81 of the retaining portion 8C in the radial direction and supports the rear surface of the flange portion 8A in the axial direction.

[0170] The spindle 8 is supported by a spindle bearing 44 at a holding portion 8C disposed at the rear, and is supported by an anvil 10 at a spindle recess 8E disposed at the front. The anvil 10 is supported by a bearing 46. The front portion of the spindle 8 is rotatably supported by the bearing 46 via the anvil 10.

[0171] The holding portion 8C has a circular inner peripheral surface 82. The holding portion 8C holds the rotor bearing 39F on the inner peripheral surface 82.

[0172] The rotor bearing 39F has an annular shape. It is positioned on the inner circumferential surface of the main shaft 8. It is positioned on the inner circumferential surface 82 of the retaining portion 8C. The rotor bearing 39F supports the outer circumferential surface of the rotor shaft 33. The rotor bearing 39F comprises a rolling bearing. It includes an inner ring 60A, an outer ring 60B, and rolling elements. While the type of rolling bearing is not particularly limited, in this embodiment, the rotor bearing 39F is a ball bearing. The rolling elements of the rotor bearing 39F are balls 60C. The rolling elements may alternatively be rollers or needle rollers. The outer ring 60B of the rotor bearing 39F contacts the inner circumferential surface 82 of the retaining portion 8C. The inner ring 60A of the rotor bearing 39F contacts the outer circumferential surface of the rotor shaft 33. The outer ring 60B of the rotor bearing 39F is fixed to the inner circumferential surface 82 of the retaining portion 8C, and the inner ring 60A of the rotor bearing 39F rotates together with the rotor shaft 33. The balls 60C of the rotor bearing 39F are arranged radially between the inner ring 60A and the outer ring 60B. The balls 60C of the rotor bearing 39F are in contact with the inner ring 60A and the outer ring 60B. A plurality of balls 60C of the rotor bearing 39F are arranged circumferentially.

[0173] like Figure 11 As shown, the main shaft 8 has an insertion hole 8G extending forward from the inner circumference of the retaining portion 8C. Insertion hole 8G extends axially at the center of the flange portion 8A and the shaft portion 8B. The interior of the retaining portion 8C communicates with insertion hole 8G. The pinion gear 41 at the front end of the rotor shaft portion 33 passes through the interior of the retaining portion 8C and is positioned in insertion hole 8G. The pinion gear 41 meshes with the planetary gear 42 within insertion hole 8G. The inner diameter of the retaining portion 8C is larger than that of the insertion hole 8G. In other words, the inner circumferential surface of the flange portion 8A is positioned radially inward relative to the inner circumferential surface 82 of the retaining portion 8C. The rotor bearing 39F is located inside the retaining portion 8C and axially contacts the rear surface of the flange portion 8A. The flange portion 8A serves as a positioning portion for the rotor bearing 39F in the front-rear direction.

[0174] Inside the retaining portion 8C, the rear portion of the pinion 41 and the non-gear portion 33A of the rotor shaft 33 are located further rearward of the pinion 41. The inner race 60A of the rotor bearing 39F contacts the outer circumferential surface of the non-gear portion 33A of the rotor shaft 33. The inner race 60A of the rotor bearing 39F also contacts the outer circumferential surface of the pinion 41. In other words, the rotor bearing 39F is positioned so as to span the non-gear portion 33A and the rear portion of the pinion 41. The length L2 of the axial contact area of ​​the rotor bearing 39F with the pinion 41 is greater than the length L1 of the contact area with the non-gear portion 33A. This reduces the distance between the rotor bearing 39F and the planetary gear 42 in the front-to-rear direction compared to a case where the rotor bearing 39F is positioned only in the non-gear portion 33A (further rearward of the pinion 41), thereby shortening the overall length of the rotor shaft 33.

[0175] In the embodiment, the retaining plate portion 55 of the bearing retaining member 5, the retaining portion 8C of the main shaft 8, the spindle bearing 44, and the rotor bearing 39F are arranged in the same radial plane. Specifically, the spindle bearing 44 is arranged on the inner circumferential surface of the retaining opening 55A of the retaining plate portion 55, the retaining portion 8C is arranged on the inner circumferential surface of the spindle bearing 44 (radial bearing portion 44A), and the rotor bearing 39F is arranged on the inner circumferential surface of the retaining portion 8C. In this way, the retaining plate portion 55 of the bearing retaining member 5, the retaining portion 8C of the main shaft 8, the spindle bearing 44, and the rotor bearing 39F are arranged in a nested manner in the same plane. As a result, the longitudinal dimensions of the support structure for the main shaft 8 and rotor 27 can be shortened compared to a case where the components are staggered in the longitudinal direction.

[0176] The bearing holding member 5 holds the spindle bearing 44 while leaving both the end face (front face) of the spindle bearing 44 facing the spindle 8 and the end face (rear face) of the spindle bearing 44 facing the opposite side of the spindle 8 uncovered. The front face of the spindle bearing 44 is the sliding face 44C of the thrust bearing portion 44B, which is not covered by the bearing holding member 5 and faces the flange portion 8A. Figure 11 As can be seen, the rear surface of the main shaft bearing 44 is the rear end surface of the radial bearing portion 44A, and is not covered by the bearing retaining member 5 and faces the fan 12. Although not shown, for example, if the bearing retaining member 5 has an annular recessed portion that extends from the front surface toward the rear, and the main shaft bearing 44 is disposed within the recessed portion, the rear surface of the main shaft bearing 44 is covered by the bearing retaining member 5. In this case, a space equal to the combined thickness of the main shaft bearing 44 and the thickness of the bearing retaining member 5 covering the rear surface of the main shaft bearing 44 is required. In contrast, in the embodiment, since both the front and rear surfaces of the main shaft bearing 44 are not covered, the space required in the front-to-back direction to retain the main shaft bearing 44 is reduced.

[0177] By providing a peripheral wall portion 56 on the outer periphery of the retaining plate portion 55, the rigidity of the bearing retaining component 5 in the front-to-back direction is improved. In the embodiment, the bearing retaining component 5 forms a concave space that is recessed from the rear end surface toward the front by the retaining plate portion 55 and the peripheral wall portion 56. In addition, a fan 12 is arranged in the space surrounded by the retaining plate portion 55 and the peripheral wall portion 56 of the bearing retaining component 5. The fan 12 is opposite to the retaining plate portion 55 of the bearing retaining component 5 in the front-to-back direction. The radial outer side of the fan 12 is surrounded by the peripheral wall portion 56. The peripheral wall portion 56 has a plurality of air vents 56A. The air vents 56A pass through the peripheral wall portion 56 in the radial direction. At least a portion of the plurality of air vents 56A is opposite to the exhaust port 20 of the housing 2 in the radial direction. The peripheral wall portion 56 is provided to ensure the rigidity of the bearing retaining component 5, and space saving can be achieved by arranging the fan 12 in the space surrounded by the retaining plate portion 55 and the peripheral wall portion 56.

[0178] The positions of vent 56A and exhaust port 20 in the front-to-back direction are not completely aligned, but rather offset. Exhaust port 20 is formed with two circumferentially extending through-holes arranged in a front-to-rear arrangement, with the portion separating the two through-holes radially opposing vent 56A. Consequently, at least a portion of vent 56A radially opposes the portion of rear housing 2B other than exhaust port 20. This ensures an exhaust path through vent 56A, and prevents the entry of foreign matter through exhaust port 20 by peripheral wall portion 56.

[0179] like Figure 12 As shown, the retaining plate portion 55 is formed with an engaging recess 55B that is recessed from the front surface of the retaining plate portion 55 toward the rear. The engaging recess 55B is located near the outer periphery of the retaining plate portion 55 and is provided in plurality at intervals in the circumferential direction. The engaging recess 55B extends in an arc shape along the outer periphery of the retaining plate portion 55. The engaging protrusion 43A of the internal gear 43 is disposed in the engaging recess 55B. The engaging protrusion 43A protrudes toward the rear from the rear end surface of the internal gear 43. Corresponding to the engaging recess 55B of the retaining plate portion 55, a plurality of engaging protrusions 43A are provided at intervals in the circumferential direction of the internal gear 43. By engaging the engaging protrusions 43A with the engaging recesses 55B, the internal gear 43 is positioned and fixed in the rotational direction.

[0180] like Figure 11As shown, the internal gear 43 is fitted into the first cylindrical portion 4A of the hammer case 4 from the rear. A stepped portion 4G is provided on the rear portion of the inner circumference of the first cylindrical portion 4A, where the internal gear 43 is positioned. In the front-to-back direction, the internal gear 43 is positioned between the wall at the front end of the stepped portion 4G and the bearing retaining member 5. An O-ring 66 is positioned at the front end of the stepped portion 4G. The O-ring 66 seals between the internal gear 43 and the hammer case 4. Its elastic deformation eliminates any play between the internal gear 43 and the hammer case 4 in the front-to-back direction, and also serves as a vibration damper to mitigate impacts.

[0181] (Example of modification of the spindle bearing)

[0182] Figure 14 : is a schematic longitudinal sectional view showing a modified example of the main shaft bearing 44. The main shaft bearing 44 may be a rolling bearing instead of a sliding bearing. Figure 14 In the figure, the spindle bearing 244 is a ball bearing. It includes an inner ring 245A, an outer ring 245B, and rolling elements (balls 245C). The outer ring 245B of the spindle bearing 244 contacts the inner circumferential surface of the retaining opening 55A of the bearing retaining member 5. The inner ring 245A of the spindle bearing 244 contacts the outer circumferential surface 81 of the retaining portion 8C of the spindle 8. The balls 245C are radially arranged between the inner ring 245A and the outer ring 245B. The balls 245C contact the inner ring 245A and the outer ring 245B, respectively. The spindle bearing 244 includes a flange 246 extending radially outward from the front end surface of the outer ring 245B. The flange 246 extends radially outward from the front end surface of the outer ring 245B. The flange 246 extends radially outward along the front surface of the retaining plate 55. The rear surface of the flange portion 246 contacts the front surface of the holding plate portion 55. The flange portion 246 functions as a positioning portion of the main shaft bearing 244 in the front-rear direction.

[0183] (Modification of Rotor Bearing)

[0184] Figure 15 : is a schematic longitudinal sectional view showing a modified example of the rotor bearing 39F. The rotor bearing 39F may be a sliding bearing instead of a rolling bearing. Figure 15 In the embodiment, rotor bearing 239F includes a sliding bearing. While the type of sliding bearing is not particularly limited, rotor bearing 239F is, for example, a self-lubricating bearing (a so-called oil-free bearing). The outer circumferential surface of rotor bearing 239F is fixed to the inner circumferential surface 82 of retaining portion 8C of main shaft 8. Rotor bearing 239F supports the outer circumferential surface of rotor shaft 33. The inner circumferential surface of rotor bearing 239F serves as a sliding surface relative to rotor shaft 33.

[0185] (Modification of the Supporting Part of the Rotor Bearing)

[0186] As described above, the rotor bearing 39F is arranged to span the non-gear portion 33A and the rear portion of the pinion 41. Figure 11 In the illustrated example, the length L2 of the contact region between the rotor bearing 39F and the pinion gear 41 is greater than the length L1 of the contact region between the rotor bearing 39F and the non-gear portion 33A, but the present invention is not limited thereto. Figure 16 1 is a schematic longitudinal sectional view showing a first modified example of a support portion of the rotor bearing 39F. Figure 17 1 is a schematic longitudinal sectional view showing a second modified example of the support portion of the rotor bearing 39F.

[0187] exist Figure 16 In FIG, the length L1 of the contact area between the rotor bearing 39F and the non-gear portion 33A is equal to the length L2 of the contact area between the rotor bearing 39F and the pinion 41. Figure 17 In the embodiment, the length L1 of the contact area between the rotor bearing 39F and the non-gear portion 33A is greater than the length L2 of the contact area between the rotor bearing 39F and the pinion gear 41. Alternatively, the rotor bearing 39F may be in contact only with the non-gear portion 33A of the rotor shaft 33, rather than the pinion gear 41. Alternatively, the rotor bearing 39F may be in contact only with the pinion gear 41 of the rotor shaft 33, rather than the non-gear portion 33A of the rotor shaft 33.

[0188] [Casing and motor fixing structure]

[0189] Figure 18 It is an exploded perspective view showing the hammer case 4 and the rear case 2B according to the embodiment as seen from the front. Figure 19 It is an exploded perspective view showing the hammer case 4 and the rear case 2B according to the embodiment as seen from the rear. Figure 20 2B is a cross-sectional view showing a cross section passing through the screw member 4S connecting the hammer case 4 and the rear case 2B. Figure 20 yes Figure 13 XX-XX line sectional view. Figure 21 It is a perspective view showing the rear cabinet 2B according to the embodiment as viewed from the front. Figure 22 It is a perspective view showing the motor 6 according to the embodiment as viewed from the front. Figure 23 It is a perspective sectional view showing a cross section passing through the stator core 28 .

[0190] In the embodiment, at least a portion of the motor 6 is fixed to the motor housing portion 21 and the hammer case 4 by screw members 4S. In the embodiment, the rear case 2B is provided with the motor housing portion 21. Thus, at least a portion of the motor 6 is fixed to the rear case 2B and the hammer case 4.

[0191] The screw member 4S extends in the axial direction along the rotation axis AX. The screw member 4S extends from the rear of the motor housing 21 to the hammer case 4. The screw member 4S secures the motor housing 21 and the hammer case 4 to each other. Multiple screw members 4S are arranged to surround the motor 6 in the rotational direction. In the embodiment, four screw members 4S are provided at intervals in the rotational direction. The screw members 4S are disposed at positions corresponding to the four corners of the motor 6: the upper right, upper left, lower right, and lower left.

[0192] A screw insertion hole 21T is formed on the outer periphery of the rear surface portion 21B of the motor housing portion 21 (see Figure 20 The motor housing portion 21 includes a boss portion 21H having screw insertion holes 21T through which the screw members 4S are inserted. Four boss portions 21H and screw insertion holes 21T are formed at intervals in the direction of rotation. The boss portion 21H is formed on the peripheral surface portion 21A of the motor housing portion 21 so as to cover the outside of the screw members 4S. The boss portion 21H has a semi-cylindrical shape, similar to a cylinder divided in half.

[0193] In the motor 6, the stator 26 is secured to the motor housing 21 and the hammer case 4 by screws 4S. The outer periphery of the stator 26 is clamped between the motor housing 21 and the hammer case 4 by the screws 4S. In the embodiment, the stator core 28 is clamped between the motor housing 21 and the hammer case 4 by the screws 4S. Furthermore, the insulators are clamped between the motor housing 21 and the hammer case 4 by the screws 4S. Specifically, either the front insulator 29 or the rear insulator 30 is clamped between the motor housing 21 and the hammer case 4 by the screws 4S. In the embodiment, the stator core 28 and the rear insulator 30 are fixed to each other by the screws 4S to the motor housing 21 and the hammer case 4. The front insulator 29 is not secured by the screws 4S.

[0194] The outer periphery of the stator core 28 and the outer periphery of the rear insulator 30 are positioned approximately at the same radial position. At least a portion of the outer periphery of the rear surface of the stator core 28 is covered by the outer periphery of the rear insulator 30. The outer periphery of the front insulator 29 is positioned radially inward of the outer periphery of the stator core 28. At least a portion of the outer periphery of the front surface of the stator core 28 is positioned outward of the outer periphery of the front insulator 29 and is exposed from the front insulator 29.

[0195] The bearing holding member 5 has a boss portion 5H for inserting the screw member 4S. The hammer case 4 has a boss portion 4H formed with a threaded hole for attaching the screw member 4S. The screw member 4S is inserted from the screw insertion hole 21T (see FIG. 21 ) of the motor housing portion 21. Figure 20), the screw insertion hole 5T of the boss portion 5H of the bearing holding member 5 passes through and engages with the threaded hole 4T formed in the boss portion 4H of the hammer case 4. The bearing holding member 5 is fastened between the motor housing portion 21 and the hammer case 4 by the screw member 4S.

[0196] The boss portion 5H of the bearing retaining component 5 extends axially. The boss portion 5H has a cylindrical shape with a screw insertion hole 5T formed therein. As described above, the bearing retaining component 5 includes a retaining plate portion 55 that retains the rotor bearing 39F, and a peripheral wall portion 56 that rises from the outer periphery of the retaining plate portion 55. The boss portion 5H is formed on the peripheral wall portion 56. The boss portion 5H protrudes toward the rear end surface of the peripheral wall portion 56 toward the stator core 28. Four boss portions 5H are provided at intervals in the rotational direction. The boss portions 5H are respectively arranged at positions corresponding to the four corners of the bearing retaining component 5: the upper right, upper left, lower right, and lower left. The axial dimension of the boss portion 5H is larger than the axial dimension of the peripheral wall portion 56. The bearing retaining component 5 has a rib 57 that protrudes from the boss portion 5H along the circumference of the stator 26 (i.e., the circumference of the peripheral wall portion 56). A pair of ribs 57 are formed so as to protrude outward from the boss portion 5H along the circumference of the peripheral wall portion 56. The outer periphery of the stator 26 contacts the end faces of the boss portion 5H and the end faces of the ribs 57. Specifically, the outer periphery of the front surface of the stator core 28, which is further outward than the front insulator 29, contacts the boss portion 5H and the rear end faces of the ribs 57.

[0197] The hammer case 4 has four bosses 4H spaced apart in the rotational direction. These bosses 4H are located at positions corresponding to the four corners of the hammer case 4: the upper right, upper left, lower right, and lower left. The bosses 4H are located at the rear end of the hammer case 4. Accordingly, a threaded hole 4T for mounting a screw member 4S is formed at the rear end of the hammer case 4.

[0198] The inner diameter of the screw insertion hole 21T of the rear housing 2B and the inner diameter of the screw insertion hole 5T of the boss portion 5H are larger than the outer diameter of the threaded portion of the screw component 4S. That is, the screw insertion hole 21T of the rear housing 2B and the screw insertion hole 5T of the boss portion 5H do not engage with the threaded portion of the screw component 4S. The rear end face of the hammer housing 4 contacts the front end face of the bearing retaining component 5 in the front-to-back direction. The rear end face of the bearing retaining component 5 contacts the front surface of the stator core 28. That is, the rear end faces of the boss portion 5H and the rib 57 contact the outer periphery of the front surface of the stator core 28. The stator core 28 is in Figure 20The contact portion CP contacts the rear end surface of the boss portion 5H and the rib 57. The outer peripheral portion of the rear surface of the stator core 28 contacts the outer peripheral portion of the front surface of the rear insulator 30. The outer peripheral portion of the rear surface of the rear insulator 30 contacts the inner surface of the motor housing portion 21 in the axial direction. The motor housing portion 21 has a support surface 21D that contacts the rear insulator 30. The stator core 28, the rear insulator 30, and the bearing retaining member 5 are sandwiched between the rear housing 2B and the hammer case 4 by the tightening force of the screw member 4S. The outer peripheral portion of the stator 26 and the bearing retaining member 5 are fixed by being sandwiched between the motor housing portion 21 and the hammer case 4.

[0199] This allows the rear housing 2B, stator 26, and bearing retaining member 5 to be secured to the hammer case 4. Thus, in this embodiment, the rear housing 2B, motor 6, hammer case 4, and bearing retaining member 5 are collectively secured together by screw members 4S extending axially from the rear of the rear housing 2B. The outer periphery of the stator 26 and the bearing retaining member 5 are secured by being sandwiched between the motor housing 21 and the hammer case 4. The outer periphery of the stator 26 (stator core 28 and back insulator 30) is held by the motor housing 21, the end surface of the boss 5H, and the end surface of the rib 57.

[0200] The boss portion 5H also functions as a spacer, creating a space between the retaining plate portion 55 and the motor 6. The motor 6 and the retaining plate portion 55 are separated by a distance corresponding to the length of the boss portion 5H, thereby forming a space enclosed by the motor 6 and the bearing retaining member 5. The fan 12, which rotates together with the rotor 27, is positioned in the space enclosed by the motor 6, the retaining plate portion 55, and the peripheral wall portion 56. Furthermore, at least a portion of the front insulator 29 is positioned in the space enclosed by the motor 6, the retaining plate portion 55, and the peripheral wall portion 56.

[0201] Furthermore, the screw member 4S passes radially outward from the outer circumference of the stator core 28. The screw member 4S does not contact the outer circumference of the stator core 28. The screw member 4S does not contact the inner surface of the boss portion 21H of the motor housing portion 21. When the screw member 4S is inserted through the screw insertion hole 21T of the motor housing portion 21 for assembly, the shaft of the screw member 4S does not catch on the stator core 28 or the boss portion 21H, allowing for easy insertion.

[0202] [Shell split structure]

[0203] Figure 24 It is an exploded perspective view showing the housing 2 according to the embodiment. Figure 25 It is a perspective view showing the left housing 2L according to the embodiment. Figure 26 It is a perspective view showing the right housing 2R according to the embodiment. Figure 27 It is an exploded perspective view showing the connection portion between the left housing 2L and the right housing 2R. Figure 28 It is an exploded perspective view showing the rear cabinet 2B, the left housing 2L, and the right housing 2R according to the embodiment.

[0204] As described above, the housing 2 includes a left housing 2L and a right housing 2R, which are divided in a left-right direction intersecting the rotation axis AX. The grip 22 and the battery holder 23 are divided into left and right sections and provided in the left and right housings 2L and 2R, respectively. The left housing 2L includes a left portion of the grip 22 and a left portion of the battery holder 23. The right housing 2R includes a right portion of the grip 22 and a right portion of the battery holder 23.

[0205] Specifically, the grip 22 includes a left grip 22L and a right grip 22R divided in the left-right direction intersecting the rotation axis AX. The battery holder 23 includes a left battery holder 23L integrally formed with the left grip 22L and a right battery holder 23R integrally formed with the right grip 22R.

[0206] The left housing 2L and the right housing 2R are fixed to each other. The left housing 2L and the right housing 2R are connected at the grip 22 and the battery retaining portion 23 by screws 2S extending in the left-right direction. The screw 2S passes through the screw insertion hole of the right housing 2R from the right side of the right housing 2R and is assembled into the threaded hole of the left housing 2L. A threaded hole is a hole formed with an internal thread that engages with an external thread. For example, the screw 2S is a self-tapping screw, and the screw 2S is fastened to the threaded bottom hole formed in the left housing 2L, thereby forming an internal thread in the threaded bottom hole by the screw 2S. The screw insertion hole and the threaded hole are provided at: 2 locations near the upper end of the grip 22, 2 locations in the middle position of the grip 22 in the vertical direction, and 2 locations in the battery retaining portion 23.

[0207] A cylindrical housing retaining portion 24, which covers the periphery of the hammer housing 4 so that the anvil (output portion) 10 protrudes forward, is integrally formed with either the left housing 2L or the right housing 2R. Specifically, the housing retaining portion 24 is integrally formed with either the left grip 22L or the right grip 22R. In the embodiment, the housing retaining portion 24 is formed in the left housing 2L (left grip 22L). Alternatively, the housing retaining portion 24 may be formed in the right housing 2R (right grip 22R).

[0208] The housing retaining portion 24 is not a split left-right structure, but rather a cylindrical, integrally formed part of the left housing 2L. The housing retaining portion 24 is not formed in the right housing 2R. That is, while the left housing 2L (left grip 22L) and the right housing 2R (right grip 22R) are split left-right, the housing retaining portion 24 is a non-split structure, formed on either side. The housing retaining portion 24 is connected to the upper end of the grip 22. The lower end of the housing retaining portion 24 is connected to the upper end of the left grip 22L of the grip 22.

[0209] Therefore, the left housing 2L includes a case holding portion 24, a left grip 22L of the grip 22, and a left battery holding portion 23L of the battery holding portion 23. The case holding portion 24, the left grip 22L of the grip 22, and the left battery holding portion 23L of the battery holding portion 23 are integrally formed on the left housing 2L. The right housing 2R includes a right grip 22R of the grip 22 and a right battery holding portion 23R of the battery holding portion 23. The right grip 22R of the grip 22 and the right battery holding portion 23R of the battery holding portion 23 are integrally formed on the right housing 2R.

[0210] The trigger shifter 14 is provided at the front of the grip 22. The forward / reverse switching shifter 15 is provided at the top of the grip 22. By dividing the grip 22 into left and right sections, the trigger shifter 14 and the forward / reverse switching shifter 15 can be easily assembled and wired.

[0211] The rear housing 2B is configured to span the left and right housings 2L and 2R. The rear housing 2B is connected to the left and right housings 2L and 2R via screws 93L and 93R, respectively. The circumferential surface 21A of the rear housing 2B is not a complete cylindrical shape, but rather has a missing arcuate shape at the bottom. The left end of the arcuate circumferential surface 21A is connected to the upper end of the left housing 2L, and the right end of the arcuate circumferential surface 21A is connected to the upper end of the right housing 2R. Two bosses 90L and 90R, through which the screws 93L and 93R pass in the front-to-back direction, are provided at the bottom of the rear surface 21B of the rear housing 2B. One boss 90L is located on the left side of the lower portion of the rear surface 21B and faces the boss 91L of the left housing 2L in the front-to-back direction. The boss 91L is provided at the upper end of the left grip 22L. The other boss portion 90R is located on the right side of the lower portion of the rear surface portion 21B and faces the boss portion 91R of the right housing 2R in the front-to-back direction. The boss portion 91R is provided at the upper end of the right grip portion 22R. Threaded holes are formed in the boss portions 91L and 91R. Screws 93L and 93R, which pass through the boss portions 90L and 90R, respectively, are attached to the boss portions 91L and 91R.

[0212] In this manner, the rear housing 2B is connected to the left housing 2L via screws 93L at the upper end of the left portion of the grip 22. The rear housing 2B is connected to the right housing 2R via screws 93R at the upper end of the right portion of the grip 22. Consequently, the motor housing 21 formed in the rear housing 2B is connected to the upper ends of the left grip 22L and the right grip 22R via screws 93L and 93R, respectively.

[0213] The case holding portion 24 has a front opening 24A and a rear opening 24B. The case holding portion 24 holds the outer periphery of the hammer case 4 by inserting the hammer case 4 from the rear opening 24B toward the front opening 24A. The inner circumferential surface of the case holding portion 24 is formed with recesses 24C that engage with protrusions 4C provided on the outer periphery of the hammer case 4. The protrusions 4C are formed at multiple locations along the circumference of the hammer case 4. Corresponding to the protrusions 4C, the case holding portion 24 has recesses 24C formed at multiple locations along the circumference of the case holding portion 24. The engagement of the protrusions 4C with the recesses 24C keeps the hammer case 4 and the case holding portion 24 engaged in the rotational direction, thereby suppressing positional deviation of the hammer case 4 in the rotational direction.

[0214] As described above, the rear housing 2B is connected to the rear portion of the hammer case 4 by screws (screw members 4S) extending in the axial direction along the rotation axis AX. The rear housing 2B is fixed to the hammer case 4 together with the bearing holding member 5 by the four screw members 4S.

[0215] The hammer case 4 is fixed to the housing 2 via a connecting member 95. The hammer case 4 is connected to the left grip 22L and the right grip 22R via the connecting member 95 extending in the left-right direction. In the embodiment, the connecting member 95 is a cylindrical pin member. The connecting member 95 is made of metal.

[0216] The hammer case 4 is provided with a connecting boss portion 4D on its outer periphery, through which a connecting member 95 extending in the horizontal direction is inserted. One connecting boss portion 4D is provided on the front and rear portions of the lower surface of the hammer case 4. The connecting boss portion 4D has a through-hole extending in the horizontal direction through which the connecting member 95 is inserted. One end and the other end of the connecting member 95 inserted through the connecting boss portion 4D protrude to the left and right sides of the connecting boss portion 4D, respectively. The connecting boss portion 4D and the connecting member 95 are disposed on the front and rear portions of the hammer case 4, respectively.

[0217] One end and the other end of the connecting member 95 inserted through the connecting boss 4D are connected to the left grip 22L and the right grip 22R, respectively. The left housing 2L includes a left support portion 96L that supports one end of the connecting member 95 inserted through the connecting boss 4D. This left support portion 96L is a cylindrical portion that receives the connecting member 95. Two left support portions 96L are provided on the left housing 2L, corresponding to the two connecting members 95. These left support portions 96L are located above the left grip 22L. The right housing 2R includes a right support portion 96R that supports the other end of the connecting member 95 inserted through the connecting boss 4D. This right support portion 96R is a cylindrical portion that receives the connecting member 95. Two right support portions 96R are provided on the right housing 2R, corresponding to the two connecting members 95. These right support portions 96R are located above the right grip 22R. Therefore, the left housing 2L and the right housing 2R are connected to the hammer case 4 via the connecting member 95 extending in the left-right direction.

[0218] In this manner, the outer periphery of the hammer case 4 is retained by the case retaining portion 24 surrounding the hammer case 4. The rear end of the hammer case 4 is retained by the rear case 2B, which is connected by four screw members 4S. The lower portion of the hammer case 4 is retained by the left and right housings 2L and 2R, which are connected by two connecting members 95. The case retaining portion 24 prevents radial and rotational positional displacement of the hammer case 4 relative to the housing 2. The two connecting members 95 prevent longitudinal positional displacement of the hammer case 4 relative to the housing 2. The two connecting members 95 and the connecting boss portion 4D prevent rotational positional displacement of the hammer case 4 relative to the housing 2.

[0219] Because the housing retaining portion 24 is not a half-split structure, it is not necessary to place horizontal screws between the hammer case 4 and the motor 6. Since the various components, such as the motor 6, bearing retaining member 5, speed reduction mechanism 7, and striking mechanism 9, are arranged axially, the axial spacing between the components must be widened to ensure space for the screws to pass through in order to accommodate the horizontal screws. Consequently, providing space for the screws increases the axial dimension of the space required to accommodate the various components. In the embodiment, since the horizontal screws are not required between the hammer case 4 and the motor 6, the axial dimension of the space required to accommodate the various components is reduced accordingly.

[0220] During assembly, the motor 6, fan 12, and other components are stacked axially within the rear housing 2B, the rotating mechanism 3 is housed in the hammer case 4, the bearing retaining member 5 is engaged with the rear portion of the hammer case 4, and the rear housing 2B and hammer case 4 are joined together using the screw member 4S. The subassembly of the rear housing 2B and hammer case 4 is inserted from the rear into the housing retaining portion 24. This allows the upper portion of the power tool 1 to be assembled. Since the housing retaining portion 24 is assembled in the left-right direction between the rear housing 2B and hammer case 4, where the components are arranged in the axial direction, the direction of the assembly work is switched 90 degrees. In this embodiment, since the assembly work is performed in the same direction (axial direction) as before, assembly workability is improved.

[0221] [Dimensions and specifications of power tools]

[0222] Next, examples of the dimensions and specifications of the various parts of the electric power tool 1 will be described. Figure 29 It is a longitudinal sectional view for explaining the dimensions of each part of the electric tool 1 according to the embodiment. Figure 29 and Figure 4 Likewise, a longitudinal section through the upper part of the power tool 1 is shown.

[0223] like Figure 29 As shown, the power tool 1 according to the embodiment has a head length L11. The head length L11 is the distance in the front-to-back direction between the front end of the anvil 10 and the rear surface of the upper portion of the power tool 1 (the rear surface of the rear housing 2B). The head length L11 is, for example, 115 mm or less, preferably 110 mm or less, and more preferably 105 mm or less. In one example shown in the embodiment, the head length L11 is 102.9 mm.

[0224] The maximum tightening torque of the electric tool 1 is, for example, 225 N·m or more, preferably 230 N·m or more, and more preferably 235 N·m or more. In addition, the so-called maximum tightening torque refers to the torque when tightening the fastening component, and generally refers to the torque measured on the fastening component after it has been tightened using the tightening torque method. The tightening torque method is a method of measuring the torque when a torque is applied to a fastening component after it has been tightened so that the fastening component starts to rotate again. In addition, it is not a method of measuring by loosening a nut or bolt. In the example shown in the embodiment, the maximum tightening torque is 230 N·m.

[0225] The power tool 1 has a motor bearing distance L12. This distance L12 is the distance in the front-to-back direction between the rear surface of the rotor shaft 33 and the front surface of the rotor bearing 39F. The motor bearing distance L12 is, for example, 35 mm or less, preferably 30 mm or less, and more preferably 25 mm or less. In one embodiment, the motor bearing distance L12 is 27.95 mm.

[0226] The power tool 1 has a motor thickness (motor cumulative thickness) L13. Motor thickness L13 is the distance in the front-to-back direction between the frontmost and rearmost surfaces of the motor 6, excluding the rotor shaft 33. Motor thickness L13 is, for example, 22 mm or less, preferably 20 mm or less, and more preferably 18 mm or less. In the example shown in the embodiment, motor thickness L13 is 17.6 mm.

[0227] The stator thickness L21 of the motor 6 is, for example, 10 mm or less, preferably 8 mm or less, and more preferably 6 mm or less. The stator thickness L21 is the distance (thickness) between the front and rear surfaces of the stator core 28. In the example shown in the embodiment, the stator thickness L21 is 5.0 mm.

[0228] The rotor length L22 of the motor 6 is, for example, 12 mm or less, preferably 10 mm or less, and more preferably 8 mm or less. The rotor length L22 is the length between the front and rear surfaces of the rotor core portion 32. In the example shown in the embodiment, the rotor length L22 is 5.5 mm.

[0229] The rotor core outer diameter D11 of the motor 6 is, for example, 22 mm or greater, preferably 24 mm or greater, and more preferably 26 mm or greater. The rotor core outer diameter D11 is the outer diameter of the rotor core portion 32. In the example shown in the embodiment, the rotor core outer diameter D11 is 27.5 mm.

[0230] The stator outer diameter D12 of the motor 6 is, for example, 45 mm or greater, preferably 47 mm or greater, and more preferably 49 mm or greater. The stator outer diameter D12 is the outer diameter of the stator 26 and, in the embodiment, is equal to the outer dimensions of the stator core 28. In the example shown in the embodiment, the stator outer diameter D12 is 50 mm.

[0231] The inner diameter of the iron core of the motor 6 is, for example, 39 mm or greater, preferably 41 mm or greater, and more preferably 43 mm or greater. The inner diameter of the iron core is the inner diameter of the iron core portion of the stator iron core 28 excluding the teeth. In the example shown in the embodiment, the inner diameter of the iron core is 43 mm.

[0232] The inner diameter of the teeth of the motor 6 is, for example, 22 mm or more, preferably 25 mm or more, and more preferably 28 mm or more. The inner diameter of the teeth is the inner diameter of the teeth in the stator core 28. In the embodiment shown, the inner diameter of the teeth is 28.5 mm.

[0233] In the example shown in the embodiment, the maximum output shaft rotation speed of the electric tool 1 is 3700 rpm. In the example shown in the embodiment, the total length of the main shaft 8 is 45.65 mm.

[0234] Regarding the electric tool 1, a distance L14 from the rear surface of the upper portion of the electric tool 1 (the rear surface of the rear housing 2B) to the front surface of the internal gear 43 is, for example, 42 mm or less, preferably 40 mm or less, and more preferably 38 mm or less. In the example shown in the embodiment, the distance L14 is 35.1 mm.

[0235] Regarding the power tool 1, a distance L15 from the rear surface of the upper portion of the power tool 1 (the rear surface of the rear housing 2B) to the rear end of the hammer housing 4 is, for example, 35 mm or less, preferably 30 mm or less, and more preferably 25 mm or less. In the example shown in the embodiment, the distance L15 is 25.1 mm.

[0236] The outer diameter of the gear of the reduction mechanism 7 is, for example, 47.5 mm or greater, preferably 47.75 mm or greater, and more preferably 48 mm or greater. The outer diameter of the gear is the outer diameter of the internal gear 43. In the example shown in the embodiment, the outer diameter of the gear is 47.5 mm. In the example shown in the embodiment, the gear ratio of the reduction mechanism 7 is 9.

[0237] The inertia moment of the hammer 47 of the electric tool 1 is, for example, 34 kg / mm 2 Above, preferably 35Kg / mm 2 More than, more preferably 36Kg / mm 2 In the example shown in the embodiment, the moment of inertia of the hammer 47 is 34.1 kg / mm. 2 In the example shown in the embodiment, the outer diameter of the hammer 47 is 43 mm.

[0238] The hammer stroke of the power tool 1 is, for example, 9 mm or greater, preferably 9.5 mm or greater, and more preferably 10 mm or greater. The hammer stroke is the distance in the front-to-back direction between the forward limit position and the backward limit position of the hammer 47. In the example shown in the embodiment, the hammer stroke is 9.11 mm.

[0239] The installation load of the coil spring 49 of the power tool 1 is, for example, 115 N or less, preferably 110 N or less, and more preferably 105 N or less. The installation load is the magnitude of the elastic force of the coil spring 49 when the hammer 47 is at its forward limit position. The installation load is not a load required for assembling the coil spring 49. In the example shown in the embodiment, the installation load is 120 N.

[0240] The full-stroke load of the coil spring 49 of the power tool 1 is, for example, 480 N or less, preferably 470 N or less, and more preferably 460 N or less. The full-stroke load is the magnitude of the elastic force of the coil spring 49 when the hammer 47 is at the rearward limit position. In the example shown in the embodiment, the full-stroke load is 448 N.

[0241] The spring constant of coil spring 49 is, for example, 36 N / mm or less, preferably 35 N / mm or less, and more preferably 34 N / mm or less. While the spring constant varies within the range of the hammer stroke, it is the minimum value within the range of the hammer stroke. In the example shown in the embodiment, the spring constant of coil spring 49 is 36 N / mm.

[0242] In the example shown in the embodiment, the maximum number of striking strokes of the electric tool 1 is 4600 (strokes / minute).

[0243] like Figure 20 As shown, in the embodiment, the outer periphery of the stator core 28 overlaps with the head of the screw member 4S in the front-to-back direction. The outer periphery of the stator core 28 and the head of the screw member 4S overlap within the range of the length L16 in the radial direction of the screw member 4S. That is, the length L16 is the distance between the outer periphery of the stator core 28 and the outer periphery of the head of the screw member 4S in the radial direction of the screw member 4S. The length L16 is, for example, greater than 0 mm, preferably greater than 0.5 mm, and more preferably greater than 1 mm. In addition, in this specification, a housing with a length L16 = 0, that is, a case where the outer periphery of the stator core 28 and the outer periphery of the head of the screw member 4S are in contact at one point when viewed from the front-to-back direction, is also considered to be overlapping. In the example shown in the embodiment, the length L16 is 1.4 mm.

[0244] Thus, the embodiment discloses an impact driver having a head length L11 of 115 mm or less and a maximum tightening torque of 225 N·m or greater. Furthermore, the embodiment discloses an impact driver having a flat rotor 27 with a length (rotor length L22) of 10 mm or less and a diameter (rotor core outer diameter D11) of 25 mm or greater. Furthermore, the embodiment discloses an impact driver having a flat, annular stator 26 with a length (stator thickness L21) of 10 mm or less and a diameter (stator outer diameter D12) of 45 mm or greater.

[0245] [Power tool movement]

[0246] Next, the operation of the electric power tool 1 will be described.

[0247] When tightening a screw on an object, the tool tip (driver bit) used for the screw tightening operation is inserted into the tool hole 10A of the anvil 10. The tool tip inserted into the tool hole 10A is held by the tool holding mechanism 11. After the tool tip is attached to the anvil 10, the operator grasps the grip 22 with, for example, their right hand and pulls the trigger paddle 14. Pulling the trigger paddle 14 supplies power from the battery pack 25 to the motor 6, activating the motor 6 and lighting the lamp assembly 18. The activation of the motor 6 causes the rotor shaft 33 of the rotor 27 to rotate. As the rotor shaft 33 rotates, its rotational force is transmitted to the planetary gear 42 via the pinion 41. The planetary gear 42, meshing with the internal teeth of the internal gear 43, rotates while orbiting around the pinion 41. The planetary gear 42 is rotatably supported on the spindle 8 by a pin 42P. The revolution of the planetary gears 42 causes the main shaft 8 to rotate at a rotational speed lower than the rotational speed of the rotor shaft 33 .

[0248] When the spindle 8 rotates while the hammer 47 is in contact with the anvil protrusion 10D, the anvil 10 rotates along with the hammer 47 and the spindle 8. The rotation of the anvil 10 enables screw tightening. The rotational force of the spindle 8 is transmitted to the hammer 47 via the ball bearings 48. When the spindle 8 rotates along with the hammer 47, the ball bearings 48 are positioned in front of the spindle groove 8D.

[0249] When a load torque exceeding a predetermined value is applied from the screw to the anvil 10 during screw tightening, the rotation of the anvil 10 and the hammer 47 stops. Since the spindle 8 is continuously rotated by the motor 6, if the spindle 8 continues to rotate while the hammer 47 is stopped, the hammer 47 moves rearward relative to the spindle 8. Specifically, the ball 48 moves rearward along the spindle groove 8D, and the hammer 47 moves rearward as the ball 48 moves.

[0250] As the hammer 47 moves rearward relative to the spindle 8, contact between the hammer 47 and the anvil protrusion 10D is released. After the hammer 47 and the anvil protrusion 10D are released, the rearward movement of the hammer 47 is stopped by the forward force of the coil spring 49. The stopped hammer 47 rotates and moves forward due to the forward force of the coil spring 49. As the hammer 47 moves forward relative to the spindle 8, the ball 48 moves forward along the spindle groove 8D.

[0251] The hammer 47 moves forward while rotating, and the anvil 10 is struck in the rotation direction by the hammer 47. As a result, the anvil 10 rotates around the rotation axis AX with a high torque. As a result, the screw is tightened to the workpiece with a high torque.

[0252] [Effect]

[0253] As described above, in the embodiment, the power tool 1 includes: a motor 6; a motor housing 21 that houses the motor 6; a rotating mechanism 3 including an anvil (output unit) 10 that is disposed forward of the motor 6 and rotates based on the rotational force of the motor 6; a hammer case (rotating mechanism case) 4 that is disposed forward of the motor housing 21 and houses at least a portion of the rotating mechanism 3; and a screw member 4S that extends from the rear of the motor housing 21 to the hammer case 4 and secures the motor housing 21 and the hammer case 4 to each other. The motor 6 is secured to the motor housing 21 and the hammer case 4 together by the screw member 4S.

[0254] According to the above configuration, the motor 6 within the motor housing 21 can be secured together with the motor housing 21 and the hammer case 4 by the screw members 4S extending in the front-to-back direction, which secure the motor 6 to each other. This eliminates the need for space for locating the screws extending in the left-to-right direction between the motor 6 and the rotating mechanism 3. Furthermore, compared to a method where separate screws are used to secure the motor housing 21 (which houses the motor 6) to the hammer case 4 and to secure the motor 6 within the motor housing 21, the space required for screw placement can be reduced. Consequently, the increase in the overall length of the power tool 1 caused by the screws securing the housing 2 can be suppressed. Furthermore, the number of components and weight reduction of the power tool 1 can be achieved.

[0255] In the embodiment, the motor 6 includes a rotor 27 that rotates about a rotation axis AX and a stator 26 disposed around the rotor 27. The outer periphery of the stator 26 is clamped between the motor housing 21 and the hammer case (rotating mechanism case) 4 by screw members 4S.

[0256] According to the above-described configuration, the motor housing portion 21 , the hammer case 4 , and the stator 26 can be collectively fixed together using the same screw members 4S.

[0257] In the embodiment, the stator 26 includes a stator core 28, an insulator made of an electrically insulating member, and a coil disposed on the stator 26 via the insulator. The stator core 28 is clamped between the motor housing 21 and the hammer case (rotating mechanism case) 4 by screws 4S.

[0258] According to the above configuration, the stator core 28 of the stator 26 can be fixed together with the motor housing 21 and the hammer case 4 by the screw members 4S. The stator core 28 is formed of a laminated body of steel plates and has high rigidity. Therefore, by clamping the stator core 28, the stator 26 can be firmly fixed.

[0259] In the embodiment, the stator 26 includes a stator core 28, an insulator made of an electrically insulating member, and a coil 31 disposed on the stator 26 via the insulator. The insulator is clamped between the motor housing 21 and the hammer case (rotating mechanism case) 4 by screws 4S.

[0260] According to the above configuration, the insulator in the stator 26 can be fixed together with the motor housing 21 and the hammer case 4 by the screw member 4S. For example, unlike a case where a separate member for being clamped by the screw member 4S is provided on the stator 26, the number of parts does not increase, thereby achieving a reduction in the number of parts and a reduction in weight of the power tool 1.

[0261] In the embodiment, the insulators include a front insulator 29 provided at the front portion of the stator core 28, and a rear insulator 30 provided at the rear portion of the stator core 28. Each of the front insulator 29 and the rear insulator 30 is clamped between the motor housing 21 and the hammer case (rotating mechanism case) 4 by a screw member 4S.

[0262] According to the above configuration, the screw member 4S can clamp one of the front insulator 29 and the rear insulator 30 without clamping the other. This reduces the influence of dimensional tolerance compared to clamping both the front insulator 29 and the rear insulator 30.

[0263] In the embodiment, the power tool 1 further includes a bearing holding member 5 having a rotor bearing 39F that rotatably supports the rotor 27. The stator 26 is fixed between the motor housing 21 and the hammer case (rotating mechanism case) 4 together with the bearing holding member 5 by screws 4S.

[0264] According to the above configuration, not only the stator 26 but also the bearing holding member 5 can be fixed together with the motor housing 21 and the hammer case 4 by the same screw member 4S. This can more effectively reduce the number of parts and weight of the electric power tool 1.

[0265] In the embodiment, the outer peripheral portion of the stator 26 and the bearing holding member 5 are fixed by being sandwiched between the motor housing portion 21 and the hammer case (rotating mechanism case) 4 .

[0266] According to the above configuration, the outer periphery of the stator 26 and the bearing holding member 5 are clamped and fixed by the motor housing 21 and the hammer case 4 , and the rotor 27 can be rotatably supported by the rotor bearing 39F of the bearing holding member 5 .

[0267] In the embodiment, the bearing holding member 5 includes a boss portion 5H extending in the axial direction and through which the screw member 4S is inserted. The outer periphery of the stator 26 is sandwiched between the motor housing portion 21 and the end surface of the boss portion 5H.

[0268] According to the above configuration, by providing the boss portion 5H on the bearing holding member 5, the axial force of the screw member 4S can be effectively applied to the bearing holding member 5 for fixation. Furthermore, the boss portion 5H of the bearing holding member 5 can be utilized as a contact portion for fixing the stator 26.

[0269] In the embodiment, the bearing holding member 5 includes a rib 57 that protrudes from the boss portion 5H along the circumferential direction of the stator 26. The outer peripheral portion of the stator 26 contacts the end surface of the boss portion 5H and the end surface of the rib 57.

[0270] According to the above configuration, the rigidity of the boss portion 5H can be increased by providing the rib 57 on the boss portion 5H. Furthermore, by making the end faces of the boss portion 5H and the end faces of the rib 57 contact the outer periphery of the stator 26, the contact area between the bearing retaining member 5 and the stator 26 can be increased. Consequently, the stability of the fixing by the screw member 4S can be improved.

[0271] In the embodiment, the bearing retaining member 5 includes a retaining plate 55 that retains the rotor bearing 39F, and a peripheral wall 56 that rises from the outer periphery of the retaining plate 55 and has a boss 5H formed thereon. The power tool 1 further includes a fan 12 that rotates together with the rotor 27 within the space enclosed by the motor 6, the retaining plate 55, and the peripheral wall 56.

[0272] With the above-described configuration, since the end surface of boss portion 5H provided on peripheral wall portion 56 contacts stator 26, boss portion 5H functions as a spacer, creating a gap between motor 6 (rotor 27 and stator 26) and retaining plate portion 55 of bearing retaining member 5. By arranging fan 12 in the space thus formed, a structure that efficiently cools motor 6 is achieved without the need for separate spacers for adjusting the positions of the various components.

[0273] In the embodiment, the screw member 4S passes through the outer side in the radial direction of the stator core 28 .

[0274] According to the above configuration, the screw member 4S and the stator 26 can be prevented from contacting each other without providing a special structure between the screw member 4S and the stator 26. This prevents the stator core 28 and the screw member 4S from contacting each other during assembly of the power tool 1 or during operation of the power tool 1, thereby preventing wear or peeling of the steel plate.

[0275] In the embodiment, the bearing holding member 5 is made of metal.

[0276] The above-described structure can easily achieve high mechanical strength or high rigidity. In addition, the bearing holding member 5 can also be made of resin. When the bearing holding member 5 is made of resin, it can be easily formed into a shape suitable for being fixed between the motor housing portion 21 and the hammer case 4 by the axial force of the screw member 4S.

[0277] In the embodiment, the plurality of screw members 4S are arranged so as to surround the motor 6 in the rotation direction.

[0278] According to the above-described configuration, the motor 6 can be firmly fixed without separately providing dedicated screws for fixing the motor 6 inside the motor housing portion 21 .

[0279] In the embodiment, the hammer case (rotating mechanism case) 4 is made of metal. A screw hole for fitting a screw member 4S is formed at the rear end portion of the hammer case 4 .

[0280] According to the above configuration, since a metal case having high mechanical strength and rigidity can be used as the hammer case 4, the motor housing portion 21 and the motor 6 can be stably fixed. In addition, for example, there is no need to embed a metal nut member or the like only in the threaded hole portion, and the threaded hole can be directly formed in the hammer case 4.

[0281] In the embodiment, the power tool 1 is an impact tool. The power tool 1 includes: a motor 6; a motor housing 21 that houses the motor 6; a rotating mechanism 3 that includes a hammer 47 positioned forward of the motor 6 and rotated about a rotation axis AX by the motor 6, and an anvil 10 that is struck in the rotational direction by the hammer 47; a hammer case (rotating mechanism case) 4 that is positioned forward of the motor housing 21 and houses at least a portion of the rotating mechanism 3; and a screw member 4S that extends from the rear of the motor housing 21 to the hammer case 4 and secures the motor housing 21 and the hammer case 4 to each other. At least a portion of the motor 6 is secured to the motor housing 21 and the hammer case 4 by the screw member 4S.

[0282] According to the above configuration, the motor 6 within the motor housing 21 is secured together with the motor housing 21 and the hammer case 4 by the screw members 4S extending in the front-to-back direction, thereby securing the motor 6 therein. This eliminates the need for space for locating the left-to-right screws between the motor 6 and the rotating mechanism 3. Furthermore, compared to a method where separate screws are used to secure the motor housing 21 (which houses the motor 6) to the hammer case 4 and to secure the motor 6 within the motor housing 21, the space required for screw placement can be reduced. Consequently, the increase in the overall length of the impact tool caused by the screws securing the housing 2 can be suppressed. Furthermore, the number of components and weight reduction of the impact tool can be achieved.

[0283] [Other embodiments]

[0284] In the above embodiment, the structure is as follows: the internal gear 43 (refer to Figure 12 ) is provided with a rearwardly projecting engagement projection 43A on the rear end surface of the bearing retaining member 5. The engagement projection 43A is fitted into the engagement recess 55B of the bearing retaining member 5, thereby positioning and securing the internal gear 43 in the rotational direction. The internal gear 43 may also be positioned and secured in the rotational direction by engagement with the hammer case 4 rather than by the bearing retaining member 5. Figure 30 It is a longitudinal sectional view showing an upper portion of an electric power tool 1 according to another embodiment. Figure 31 It is an exploded perspective view showing a bearing holding member, an internal gear, and a hammer case according to another embodiment, as seen from the rear.

[0285] exist Figure 30 as well as Figure 31In the example shown, the internal gear 43 is fitted into the first cylindrical portion 4A of the hammer case 4 from the rear. A stepped portion 4G for arranging the internal gear 43 is provided at the rear of the inner peripheral surface of the first cylindrical portion 4A. The stepped portion 4G is a step that is recessed radially outward on the inner peripheral surface of the first cylindrical portion 4A. Figure 31 As shown, the internal gear 43 has an engaging protrusion 43B protruding toward the front from the front end surface of the internal gear 43. An engaging recess 4F for the engaging protrusion 43B to engage with is formed on the stepped portion 4G of the hammer housing 4. A plurality of engaging protrusions 43B are formed at intervals in the circumferential direction of the internal gear 43. A plurality of engaging recesses 4F are formed at intervals in the circumferential direction of the hammer housing 4. Each engaging protrusion 43B and each engaging recess 4F are formed at the same position in the circumferential direction and are opposite to each other in the front-to-back direction. By engaging the engaging protrusions 43B with the engaging recesses 4F, the internal gear 43 is positioned and fixed in the rotational direction. As shown in FIG. Figure 30 As shown, the internal gear 43 is positioned in the front-to-back direction between the wall at the front end of the stepped portion 4G and the bearing retaining member 5. An O-ring 67 is provided at the rear end of the internal gear 43. The O-ring 67 seals between the internal gear 43 and the hammer case 4. The O-ring 67 elastically deforms to eliminate play in the front-to-back direction between the internal gear 43 and the bearing retaining member 5, and also functions as a vibration damper to mitigate shock.

[0286] In the above embodiment, the power tool 1 is an impact driver, but the power tool 1 may also be an impact wrench. Figure 32 It is a perspective view showing an electric tool 1A according to another embodiment as viewed from the rear.

[0287] Figure 32 The electric tool 1A is an impact wrench, which is a type of impact tool. The anvil (output portion) 210 of the electric tool 1A includes an anvil shaft portion 210A for assembling a front end tool. The anvil shaft portion 210A is arranged at the front portion of the anvil 210. The anvil shaft portion 210A protrudes further forward than the cylindrical shell retaining portion 224. The housing 202 includes a motor accommodating portion 221, a gripping portion 222, and a cylindrical shell retaining portion 224. The housing 202 is divided into a left housing 202L and a right housing 202R. The left housing 202L is integrally formed with: a cylindrical shell retaining portion 224, a motor accommodating portion 221, and a left side portion of the gripping portion 222 (left gripping portion 222L). The right housing 202R is integrally formed with: a right side portion of the gripping portion 222 (right gripping portion 222R). The left housing 202L and the right housing 202R are fixed at multiple locations by screws 2S in the left-right direction. The right housing 202R is fixed to the motor housing portion 221 by screws 222S provided on the upper front portion of the right grip portion 222R. Figure 32In the example of FIG, the battery holding portion 223 is provided in a battery case 225 that is separate from the case 202. The battery case 225 is fixed to the case 202 by screws.

[0288] The hammer housing (rotating mechanism housing) 204 is inserted into the housing retaining portion 224 from the front. The housing retaining portion 224 has a cylindrical shape, with an open front and a rear portion connected to the motor housing portion 221. The motor housing portion 221 accommodates the motor 6. A screw component 204S extending axially is inserted from the rear of the motor housing portion 221. The screw component 204S reaches the hammer housing 204. The screw component 204S engages with the threaded hole formed in the boss portion 204H of the hammer housing 204. The motor 6 is fixed together with the motor housing portion 221 and the hammer housing 204 by the screw component 204S. The electric power tool 1A is a large impact wrench, and the side handle 400 can be installed and removed.

[0289] In the above embodiment, the electric tool 1 is an impact tool. However, the electric tool 1 may be a tool other than an impact tool. Figure 33 It is a perspective view showing an electric tool 1B according to another embodiment as viewed from the rear. Figure 33 The power tool 1B is a drive drill, a type of drilling machine. The power tool 1B includes a motor; a motor housing 321 housing the motor; a rotating mechanism including an output unit 310 positioned forward of the motor and rotating based on the motor's torque; and a rotating mechanism housing 304 positioned forward of the motor housing 321 and housing at least a portion of the rotating mechanism.

[0290] The output part 310 is arranged at a position further forward than the motor. The output part 310 is rotated by the rotational force of the motor. The output part 310 is rotated in a state where the front end tool is installed. The rotating mechanism portion includes: a speed reduction mechanism and a vibration mechanism. At least a part of the speed reduction mechanism is accommodated in the rotating mechanism housing 304. At least a part of the vibration mechanism is accommodated in the rotating mechanism housing 304. The speed reduction mechanism reduces the rotation of the motor (rotor shaft) so that the output part 310 rotates at a rotation speed lower than that of the rotor shaft. The vibration mechanism causes the output part 310 to vibrate in the axial direction. The vibration mechanism includes: a plurality of cams that rotate based on the rotational force of the motor, and converts the rotation of the cams into axial reciprocating motion. The vibration mechanism causes the output part 310 to vibrate in the axial direction based on the axial reciprocating motion of the cams.

[0291] The housing 302 includes a motor housing 321, a grip 322, a battery holder 323, and a cylindrical housing holder 324. The housing 302 is divided into a left housing 302L and a right housing 302R. The left housing 302L integrally forms the cylindrical housing holder 324, the motor housing 321, the left side of the grip 322 (the left grip 322L), and the left side of the battery holder 323 (the left battery holder 323L). The right housing 302R integrally forms the right side of the grip 322 (the right grip 322R) and the right side of the battery holder 323 (the right battery holder 323R). The left and right housings 302L and 302R are fixed together at multiple locations using screws in the left-right direction.

[0292] The housing retaining portion 324 has a cylindrical shape, with an open front portion and a rear portion connected to the motor housing portion 321. The motor housing portion 321 has a cylindrical shape, and the rear portion is covered by a rear cover 325. The rotating mechanism housing 304 is inserted into the housing retaining portion 324 from the front. The motor housing portion 321 houses the motor. A screw component 304S extending in the axial direction is inserted from the rear of the motor housing portion 321. The screw component 304S passes through the motor housing portion 321 from the screw insertion hole formed in the rear cover 325 and reaches the rotating mechanism housing 304. The screw component 304S engages with a threaded hole formed in the boss portion 304H of the rotating mechanism housing 304. The motor housed in the motor housing portion 321 is fixed together with the motor housing portion 321 and the rotating mechanism housing 304 by the screw component 304S.

[0293] In the above embodiment, the power source of the electric tool 1 may be a commercial power source (AC power source) instead of the battery pack 25 . The commercial power source inputs a voltage of 18V or higher to the motor 6 .

Claims

1. An electric tool, characterized in that: The electric tool comprises: a motor; a motor housing portion that houses the motor; a rotating mechanism portion that includes an output portion that is arranged further forward than the motor and rotates based on the rotational force of the motor; a rotating mechanism housing disposed in front of the motor housing portion and housing at least a portion of the rotating mechanism portion; and a screw member extending from the rear of the motor housing portion to the rotating mechanism housing to secure the motor housing portion and the rotating mechanism housing to each other. The motor is fixed together with the motor housing portion and the rotating mechanism case by the screw member.

2. The electric tool according to claim 1, wherein: The motor includes a rotor that rotates around a rotation axis and a stator disposed around the rotor. The outer peripheral portion of the stator is clamped between the motor housing portion and the rotating mechanism case by the screw member.

3. The electric tool according to claim 2, wherein: The stator includes a stator core, an insulator formed of an electrical insulating member, and a coil arranged on the stator via the insulator. The stator core is clamped between the motor housing portion and the rotating mechanism case by the screw member.

4. The electric tool according to claim 2, wherein: The stator includes a stator core, an insulator formed of an electrical insulating member, and a coil arranged on the stator via the insulator. The insulator is held between the motor housing portion and the rotating mechanism case by the screw member.

5. The electric tool according to claim 4, wherein: The insulator includes: a front insulator provided at the front of the stator core, and a rear insulator provided at the rear of the stator core. Either the front insulator or the rear insulator is clamped between the motor housing portion and the rotating mechanism case by the screw member.

6. The electric tool according to claim 2, wherein: The electric power tool further includes: a bearing holding member having a rotor bearing for rotatably supporting the rotor; The stator is fixed between the motor housing portion and the rotating mechanism case together with the bearing holding member by the screw member.

7. The electric tool according to claim 6, wherein: The outer peripheral portion of the stator and the bearing holding member are fixed by being sandwiched between the motor housing portion and the rotating mechanism case.

8. The electric tool according to claim 7, wherein: The bearing holding member includes a boss portion through which the screw member is inserted and which extends in the axial direction. The outer peripheral portion of the stator is sandwiched between the motor housing portion and the end surface of the boss portion.

9. The electric tool according to claim 8, wherein: The bearing holding member includes a rib protruding from the boss portion along the circumferential direction of the stator. The outer peripheral portion of the stator is in contact with the end surface of the boss portion and the end surface of the rib.

10. The electric tool according to claim 8, wherein: The bearing holding member includes a holding plate portion for holding the rotor bearing, and a peripheral wall portion rising from an outer periphery of the holding plate portion and having the boss portion formed thereon. A fan that rotates together with the rotor is further provided in a space surrounded by the motor, the holding plate portion, and the peripheral wall portion.

11. The electric tool according to claim 3, wherein: The screw member passes radially outward from the outer peripheral surface of the stator core.

12. The electric tool according to claim 8, wherein: The bearing holding member is made of metal or resin.

13. The electric tool according to claim 1, wherein: The plurality of screw members are arranged so as to surround the motor in the rotation direction.

14. The electric tool according to claim 1, wherein: The rotating mechanism housing is made of metal. A threaded hole for fitting the screw member is formed at the rear end portion of the rotating mechanism housing.

15. An impact tool, characterized in that: The impact tool comprises: a motor; a motor housing portion that houses the motor; a rotating mechanism portion that includes a hammer that is arranged at a position further forward than the motor and rotated around a rotating axis by the motor, and an anvil that is struck in a rotational direction by the hammer; a rotating mechanism housing that is arranged in front of the motor housing portion and houses at least a portion of the rotating mechanism portion; and a screw member that reaches the rotating mechanism housing from the rear of the motor housing portion to fix the motor housing portion and the rotating mechanism housing to each other. At least a portion of the motor is fixed together with the motor housing portion and the rotating mechanism case by the screw member.

Images