Screwdriver

Abstract

To provide a screwdriver equipped with a push-drive mechanism, which is configured so that an entire length of the driver is suppressed from becoming longer.SOLUTION: A screwdriver is equipped with: a pinion gear that is rotated by a motor; a driving gear that rotates with a first rotary shaft as a center while engaging with the pinion gear; a spindle, supported on a housing movably in a longitudinal direction at a place closer to a front side than the driving gear, which can rotate with the first rotary shaft as a center while being mounted with a tip tool; a driving cam part that is rotated with the first rotary shaft as a center by the driving gear; a driven cam part, arranged closer to the front side than the driving cam part, which moves in the longitudinal direction together with the spindle so as to contact the driving cam part or separate from the driving cam part; a magnet that moves in the longitudinal direction in synchronization with the spindle; a magnet sensor, arranged outside in a radial direction of the first rotary shaft, which detects the magnet; and a controller that controls the motor on the basis of a detected signal by the magnet sensor.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The technology disclosed herein relates to a screwdriver. [Background technology]

[0002] In the technical field relating to screwdrivers, a screwdriver equipped with a push drive mechanism (also called Auto Start), as disclosed in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-012471 Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the structure of the push drive mechanism, the overall length of the screwdriver may become long.

[0005] The technology disclosed in this specification aims to prevent an increase in the overall length of a screwdriver equipped with a push drive mechanism. [Means for solving the problem]

[0006] This specification discloses a screwdriver. The screwdriver may include a housing, a motor, a pinion gear rotated by the motor, a drive gear rotating about a first rotating shaft while meshing with the pinion gear, a spindle supported on the housing forward of the drive gear so as to be movable in the front-rear direction and rotatable about the first rotating shaft while a tool tip is attached, a drive cam portion rotating about the first rotating shaft by the drive gear, a driven cam portion disposed forward of the drive cam portion and moving in the front-rear direction together with the spindle so as to contact the drive cam portion or move away from the drive cam portion, a support shaft rotating about the first rotating shaft while supporting the drive gear, a first bearing disposed rearward of the drive gear and rotatably supporting the support shaft, a magnet disposed forward of the first bearing and moving in the front-rear direction in synchronization with the spindle, a magnetic sensor disposed radially outward of the first rotating shaft and detecting the magnet, and a controller controlling the motor based on a detection signal of the magnetic sensor. Effect of the Invention

[0007] The technology disclosed in this specification makes it possible to prevent the overall length of a screwdriver equipped with a push drive mechanism from increasing. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a front perspective view showing a screwdriver according to an embodiment. [Diagram 2] FIG. 2 is a rear perspective view showing the screwdriver according to the embodiment. [Diagram 3] FIG. 3 is a side view showing the screwdriver according to the embodiment. [Figure 4] FIG. 4 is a vertical cross-sectional view showing the screwdriver according to the embodiment. [Diagram 5] FIG. 5 is an enlarged longitudinal sectional view of a portion of the screwdriver according to the embodiment. [Figure 6] FIG. 6 is an enlarged longitudinal sectional view of a main part of the screwdriver according to the embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a part of the screwdriver according to the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a screwdriver according to an embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a screwdriver according to an embodiment. [Figure 10] FIG. 10 is an exploded perspective view from the front showing a main part of the screwdriver according to the embodiment. [Figure 11] FIG. 11 is an exploded perspective view showing the main parts of the screwdriver according to the embodiment, as seen from the rear. [Figure 12] FIG. 12 is a vertical cross-sectional view showing a main part of a screwdriver according to a modified example. [Figure 13] FIG. 13 is a vertical cross-sectional view showing a main part of a screwdriver according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one or more embodiments, the screwdriver may include a housing, a motor, a pinion gear rotated by the motor, a drive gear that rotates about a first rotating shaft while meshing with the pinion gear, a spindle that is supported on the housing forward of the drive gear so as to be movable in a front-to-back direction and that can rotate about the first rotating shaft with a tool attached thereto, a drive cam portion that rotates about the first rotating shaft by the drive gear, a driven cam portion that is arranged forward of the drive cam portion and moves in a front-to-back direction together with the spindle so as to contact or move away from the drive cam portion, a support shaft that rotates about the first rotating shaft while supporting the drive gear, a first bearing that is arranged rearward of the drive gear and rotatably supports the support shaft, a magnet that is arranged forward of the first bearing and moves in a front-to-back direction in synchronization with the spindle, a magnetic sensor that is arranged radially outward of the first rotating shaft and detects the magnet, and a controller that controls the motor based on a detection signal of the magnetic sensor.

[0010] In the above configuration, the magnet and the magnetic sensor are disposed forward of the first bearing, so that the overall length of the screwdriver is prevented from becoming long. The overall length of the screwdriver refers to the distance in the front-rear direction between the rear end of the motor and the front end of the spindle. Note that the overall length of the screwdriver may also be the distance in the front-rear direction between the rear end of the motor and the front end of a rubber cap, which will be described later.

[0011] In one or more embodiments, the magnet may be located forward of the drive gear.

[0012] In the above configuration, the magnet and the magnetic sensor are disposed forward of the drive gear, thereby preventing the overall length of the screwdriver from becoming long.

[0013] In one or more embodiments, the position of the magnet and the position of at least a portion of the spindle may be equal in the front-to-rear direction.

[0014] In the above configuration, the position of the magnet and the position of at least a part of the spindle are the same in the front-rear direction, so that the overall length of the screwdriver is prevented from increasing.

[0015] In one or more embodiments, the screwdriver may include a moving member disposed around the spindle and moving back and forth together with the spindle. The magnet may be fixed to the moving member.

[0016] In the above configuration, the magnet is moved back and forth together with the spindle.

[0017] In one or more embodiments, the screwdriver may include a second bearing disposed between the spindle and the moving member, and a detent mechanism that inhibits rotation of the moving member relative to the housing.

[0018] In the above configuration, since the moving member does not rotate, the magnetic sensor can properly detect the magnet fixed to the moving member, and the second bearing allows the spindle to rotate.

[0019] In one or more embodiments, the screwdriver may include a clutch cam disposed around the spindle, coupled to the spindle via balls, and provided with a driven cam portion. The moving member may be disposed around the clutch cam. The second bearing may be disposed between the clutch cam and the moving member.

[0020] In the above configuration, the spindle, the clutch cam, the second bearing, and the moving member to which the magnet is fixed are moved together in the front-rear direction, so that the structure is prevented from becoming complicated.

[0021] In one or more embodiments, the screwdriver may include a guide portion that guides the moving member in the forward and backward directions.

[0022] In the above configuration, the moving member can move appropriately in the front-rear direction.

[0023] In one or more embodiments, the spindle may include a support shaft.

[0024] With the above configuration, an increase in the number of parts of the screwdriver is suppressed.

[0025] In one or more embodiments, the drive cam portion may be provided on the drive gear.

[0026] With the above configuration, an increase in the number of parts of the screwdriver is suppressed.

[0027] In one or more embodiments, the screwdriver may include a motor, a push-in clutch disposed forward of the motor and driven by the motor, a spindle disposed forward of the push-in clutch and driven by the push-in clutch, a push-in sensor disposed radially outward of the push-in clutch and detecting when the push-in clutch is pushed in, and a battery for powering the motor.

[0028] In the above configuration, the push-in magnetic sensor is disposed radially outside the push-in clutch, which prevents the overall length of the screwdriver from becoming long.

[0029] Hereinafter, an embodiment will be described with reference to the drawings. The components of the embodiment described below can be appropriately combined. In addition, there are cases where some components are not used.

[0030] In the embodiment, the positional relationship of each part will be described using the terms left, right, front, rear, top, and bottom. These terms indicate relative positions or directions based on the center of the screwdriver 1. In the embodiment, the screwdriver 1 has a spindle 9 that rotates around a rotation axis CX.

[0031] In the embodiment, the direction parallel to the rotation axis CX is appropriately referred to as the axial direction, the direction circumferential around the rotation axis CX is appropriately referred to as the circumferential direction or rotational direction, and the radial direction of the rotation axis CX is appropriately referred to as the radial direction.

[0032] A direction or position away from the center of the screwdriver 1 in a specified direction in the axial direction is appropriately referred to as one axial side, and the opposite side of the one axial side is appropriately referred to as the other axial side. A specified direction in the circumferential direction is appropriately referred to as one circumferential side, and the opposite side of the one circumferential side is appropriately referred to as the other circumferential side. A direction or position away from the rotation axis AX in the radial direction is appropriately referred to as the radial outer side, and the opposite side of the radial outer side is appropriately referred to as the radial inner side.

[0033] In the embodiment, the axial direction and the front-rear direction coincide with each other. One side in the axial direction may be regarded as the front. The other side in the axial direction may be regarded as the rear.

[0034] [Screwdriver] FIG. 1 is a front perspective view of a screwdriver 1 according to an embodiment. FIG. 2 is a rear perspective view of a screwdriver 1 according to an embodiment. FIG. 3 is a side view of a screwdriver 1 according to an embodiment. FIG. 4 is a vertical cross-sectional view of a screwdriver 1 according to an embodiment. FIG. 5 is a vertical cross-sectional view of an enlarged portion of the screwdriver 1 according to an embodiment. FIG. 6 is a vertical cross-sectional view of an enlarged portion of a main portion of the screwdriver 1 according to an embodiment. FIG. 7 is a horizontal cross-sectional view of a portion of the screwdriver 1 according to an embodiment. FIG. 8 is a cross-sectional view of a screwdriver 1 according to an embodiment, which corresponds to the cross-sectional view taken along line AA in FIG. 5. FIG. 9 is a cross-sectional view of a screwdriver 1 according to an embodiment, which corresponds to the cross-sectional view taken along line BB in FIG. 5. FIG. 10 is an exploded front perspective view of a main portion of the screwdriver 1 according to an embodiment. FIG. 11 is an exploded rear perspective view of a main portion of the screwdriver 1 according to an embodiment.

[0035] The screwdriver 1 comprises a main body housing 2, a gear housing 3, a cover 4, a battery mounting section 5, a motor 6, a fan 7, a power transmission mechanism 8, a spindle 9, a tool holding mechanism 10, a lock ring 11, an adjustment sleeve 12, a rubber cap 13, a trigger lever 14, a lock button 15, a forward / reverse rotation switch lever 16, a light 17, a switch plate 18, a bit position detection section 19, and a controller 20.

[0036] The main body housing 2 accommodates at least some of the components of the screwdriver 1. The main body housing 2 is composed of a pair of half housings. The main body housing 2 includes a left housing 2L and a right housing 2R disposed 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.

[0037] The main body housing 2 includes a motor accommodating portion 21, a handle portion 22, a battery holding portion 23, and a connecting portion 24.

[0038] The motor accommodating portion 21 accommodates the motor 6 and at least a part of the power transmission mechanism 8. The motor accommodating portion 21 is cylindrical. The motor accommodating portion 21 extends in the front-rear direction.

[0039] The handle portion 22 is gripped by an operator. The handle portion 22 has a grip portion 22A extending in the vertical direction and a connecting portion 22B extending forward from an upper portion of the grip portion 22A. A front end portion of the connecting portion 22B is connected to an upper portion of the rear end portion of the motor housing portion 21.

[0040] The battery holding portion 23 holds the battery pack 25 via the battery attachment portion 5. The battery holding portion 23 houses the controller 20. A lower end portion of the grip portion 22A is connected to the rear portion of the battery holding portion 23.

[0041] The connecting portion 24 is disposed so as to connect the lower portion of the motor accommodating portion 21 and the front portion of the battery holding portion 23 .

[0042] A loop portion of the main housing 2 is formed by the rear portion of the motor accommodating portion 21, the connecting portion 24, the battery holding portion 23, and the handle portion 22.

[0043] An intake port 26 and an exhaust port 27 are provided in the motor accommodating portion 21. The intake ports 26 are provided on both the left and right sides of the motor accommodating portion 21. The exhaust port 27 is provided in a lower portion of the motor accommodating portion 21. Air from the external space of the main body housing 2 flows into the internal space of the main body housing 2 through the intake port 26. Air from the internal space of the main body housing 2 flows out to the external space of the main body housing 2 through the exhaust port 27.

[0044] The gear housing 3 accommodates at least a part of the power transmission mechanism 8. The gear housing 3 accommodates at least a part of the spindle 9. At least a part of the gear housing 3 is disposed forward of the main housing 2.

[0045] The gear housing 3 includes a rear housing 31 and a front housing 32. At least a portion of the front housing 32 is disposed forward of the rear housing 31. At least a portion of the rear housing 31 is disposed inside a front portion of the motor accommodating portion 21. The front housing 32 is disposed forward of the motor accommodating portion 21.

[0046] The rear housing 31 has a plate portion 31A, a recess 31B recessed rearward from an upper portion of the plate portion 31A, and a tubular portion 31C protruding rearward from a lower portion of the plate portion 31A. The front housing 32 has a plate portion 32A and a tubular portion 32B protruding forward from the plate portion 32A.

[0047] The gear housing 3 is fixed to the front part of the motor accommodating portion 21. The front part of the motor accommodating portion 21, the plate portion 31A of the rear housing 31, and the plate portion 32A of the front housing 32 are fixed together by three screws 3S.

[0048] The cover 4 is disposed so as to cover at least a portion of the gear housing 3. The cover 4 includes a ring-shaped first cover portion 4A disposed around the front housing 32, a second cover portion 4B disposed in the lower part of the front housing 32, a third cover portion 4C facing the front surface of the lower part of the plate portion 32A, and a fourth cover portion 4D disposed so as to cover the lower end portion of the plate portion 31A and the lower end portion of the plate portion 32A.

[0049] The battery pack 25 is attached to the battery mounting section 5. The battery mounting section 5 is disposed at the lower part of the battery holding section 23. The battery pack 25 is detachable from the battery mounting section 5. The battery pack 25 functions as a power source for the screwdriver 1. The battery pack 25 is attached to the battery mounting section 5 by being inserted into the battery mounting section 5 from the front of the battery holding section 23. The battery pack 25 is removed from the battery mounting section 5 by being pulled forward from the battery mounting section 5. The battery pack 25 includes a secondary battery. In the embodiment, the battery pack 25 includes a rechargeable lithium ion battery. By being attached to the battery mounting section 5, the battery pack 25 can supply power to the screwdriver 1. The battery pack 25 (battery) supplies power to the motor 6. The motor 6 is driven based on the power supplied from the battery pack 25. The controller 20 and the switch plate 18 each operate based on the power supplied from the battery pack 25.

[0050] The motor 6 is a power source for the screwdriver 1. The motor 6 is an electric motor that is driven based on power supplied from the battery pack 25. The motor 6 is an inner rotor type brushless motor. The motor 6 has a stator 33 and a rotor 34. The stator 33 is supported by the motor housing portion 21. At least a portion of the rotor 34 is disposed inside the stator 33. The rotor 34 rotates relative to the stator 33. The rotor 34 rotates about a rotation axis AX that extends in the front-rear direction.

[0051] The stator 33 includes a stator core 35, a rear insulator 36R, a front insulator 36F, and a coil 37.

[0052] The stator core 35 is disposed radially outward of the rotor 34 with respect to the rotation axis AX. The stator core 35 includes a plurality of stacked steel plates. The steel plates are metal plates whose main component is iron. The stator core 35 is cylindrical. The stator core 35 has a plurality of teeth that support the coils 37.

[0053] The rear insulator 36R is fixed to a rear portion of the stator core 35. The front insulator 36F is fixed to a front portion of the stator core 35. The rear insulator 36R and the front insulator 36F are each an electrical insulating member made of synthetic resin. The rear insulator 36R is disposed so as to cover a portion of the surface of the teeth of the stator core 35. The front insulator 36F is disposed so as to cover a portion of the surface of the teeth of the stator core 35.

[0054] The coil 37 is attached to the stator core 35 via the rear insulator 36R and the front insulator 36F. A plurality of coils 37 are arranged. The coils 37 are arranged around the teeth of the stator core 35 via the rear insulator 36R and the front insulator 36F. The stator core 35 and the coils 37 are electrically insulated by the rear insulator 36R and the front insulator 36F. The plurality of coils 37 are connected to each other via a shorting member 38. Current from the battery pack 25 is supplied to the coils 37 via the controller 20, a lead wire (not shown), and a connector 39 fixed to the lower part of the rear insulator 36R. The connector 39 is fixed to the lower part of the rear insulator 36R by a screw 39S.

[0055] The rotor 34 rotates about a rotation axis AX. The rotor 34 includes a rotor core 40, a rotor shaft 41, and a rotor magnet 42.

[0056] Both the rotor core 40 and the rotor shaft 41 are made of steel. The rotor shaft 41 is fixed to the rotor core 40. The rotor core 40 is cylindrical. The rotor shaft 41 is disposed radially inward from the rotor core 40. A front portion of the rotor shaft 41 protrudes forward from a front end surface of the rotor core 40. A rear portion of the rotor shaft 41 protrudes rearward from a rear end surface of the rotor core 40.

[0057] The rotor magnet 42 is fixed to the rotor core 40. The rotor magnet 42 is disposed inside the rotor core 40. The rotor magnet 42 is disposed in a magnet hole provided in the rotor core 40.

[0058] The sleeve 29 is disposed so as to face the front end surface of the rotor core 40. The sleeve 29 is fixed to both the rotor core 40 and the rotor shaft 41. The sleeve 29 is provided to adjust the rotational balance of the rotor .

[0059] A rotation sensor board 43 is attached to the rear insulator 36R. The rotation sensor board 43 is fixed to the rear insulator 36R with screws 43S. The rotation sensor board 43 has an annular circuit board and a magnetic sensor supported by the circuit board. At least a portion of the rotation sensor board 43 faces the rotor magnet 42. The magnetic sensor detects the position of the rotor magnet 42, thereby detecting the position of the rotor 34 in the rotational direction. A detection signal from the magnetic sensor is transmitted to the controller 20 via lead wires (not shown).

[0060] The rear end of the rotor shaft 41 is rotatably supported by the rotor bearing 44. The front part of the rotor shaft 41 is rotatably supported by the rotor bearing 45. Each of the rotor bearings 44 and 45 is a ball bearing. The rotor bearing 44 is held in a recess 21A provided in the rear part of the inner surface of the motor housing part 21. The front end of the inner ring of the rotor bearing 44 contacts a step provided in the rear part of the rotor shaft 41. This suppresses the rotor bearing 44 from moving relative to the rotor shaft 41 in the front-rear direction. The rotor bearing 45 is held in the cylindrical part 31C of the rear housing 31. The rear end of the inner ring of the rotor bearing 45 contacts a step provided in the front part of the rotor shaft 41. A circlip 46 is disposed in front of the rotor bearing 45. The circlip 46 contacts a front end of the inner ring of the rotor bearing 45. This suppresses the rotor bearing 45 from moving relative to the rotor shaft 41 in the front-rear direction. The front end of the rotor shaft 41 is disposed inside the front housing 32 via an opening provided in the front end of the cylindrical portion 31C.

[0061] A pinion gear 47 is fixed to a front end of the rotor shaft 41. The pinion gear 47 is rotated about a rotation axis AX by the motor 6. The pinion gear 47 is connected to at least a part of the power transmission mechanism 8. The rotor shaft 41 is connected to the power transmission mechanism 8 via the pinion gear 47.

[0062] The fan 7 generates an airflow for cooling the motor 6. The fan 7 is disposed forward of the stator 33. The fan 7 is disposed between the rotor bearing 45 and the stator 33. The fan 7 is fixed to the rotor shaft 41 between the rotor bearing 45 and the stator 33. The fan 7 rotates with the rotation of the rotor 34. The rotor shaft 41 rotates, and the fan 7 rotates together with the rotor shaft 41. The rotation of the fan 7 causes air in the external space of the main body housing 2 to flow into the internal space of the main body housing 2 through the air intake 26. The air that has flowed into the internal space of the main body housing 2 cools the motor 6 by circulating through the internal space of the main body housing 2. The air that has circulated through the internal space of the main body housing 2 flows out through the exhaust port 27 to the external space of the main body housing 2 by the rotation of the fan 7.

[0063] The power transmission mechanism 8 transmits the rotational force of the motor 6 to the spindle 9. The power transmission mechanism 8 rotates the spindle 9 at a rotational speed lower than the rotational speed of the rotor shaft 41. In the embodiment, the power transmission mechanism 8 has a clutch mechanism 8A that transmits the rotational force of the motor 6 to the spindle 9 when the motor 6 rotates in the forward direction, and a spindle lock mechanism 8B that transmits the rotational force of the motor 6 to the spindle 9 when the motor 6 rotates in the reverse direction.

[0064] The power transmission mechanism 8 includes a drive gear 71 , a clutch cam 72 , a ball 73 , a compression spring 75 , a washer 76 , a ball 77 , and a one-way needle bearing 80 .

[0065] The clutch mechanism 8A includes a clutch cam 72 coupled to the spindle 9 via a ball 73, and a compression spring 75 that biases the clutch cam 72 and the spindle 9 forward. The drive gear 71, the clutch cam 72, and the compression spring 75 are disposed inside the gear housing 3.

[0066] The spindle lock mechanism 8B includes a one-way needle bearing 80 disposed around the spindle 9. The one-way needle bearing 80 is disposed inside the gear housing 3.

[0067] The drive gear 71 meshes with the pinion gear 47. The drive gear 71 rotates around the rotation axis CX while meshing with the pinion gear 47. The drive gear 71 is a helical gear. The drive gear 71 is disposed above the pinion gear 47. The rotation of the rotor shaft 41 of the motor 6 causes the pinion gear 47 to rotate around the rotation axis AX. The rotation of the pinion gear 47 causes the drive gear 71 to rotate around the rotation axis CX. The drive gear 71 has a ring portion 71A, a gear portion 71B, a cylindrical portion 71C, and a drive cam portion 71D. The ring portion 71A is disposed around the rotation axis CX. The gear portion 71B is provided on the outer periphery of the ring portion 71A. The gear portion 71B meshes with the pinion gear 47. The cylindrical portion 71C protrudes rearward from the rear surface of the ring portion 71A. The cylindrical portion 71C is disposed around the one-way needle bearing 80. The drive cam portion 71D is provided so as to protrude forward from the front surface of the ring portion 71A. The drive cam portion 71D rotates about the rotation axis CX by the drive gear 71. The drive gear 71 is accommodated in the rear housing 31.

[0068] The one-way needle bearing 80 is disposed around the spindle 9. The drive gear 71 is supported by the spindle 9 via the one-way needle bearing 80.

[0069] The clutch cam 72 is disposed forward of the drive gear 71. The clutch cam 72 is disposed around the spindle 9. The clutch cam 72 is coupled to the spindle 9 via a plurality of balls 73. The clutch cam 72 is supported by the spindle 9 via a plurality of balls 73. The clutch cam 72 has a support ring portion 72A, a cylindrical portion 72B, a cam ring portion 72C, a cam ball groove 72D, and a driven cam portion 72E. The support ring portion 72A is disposed around the rotation axis CX. The cylindrical portion 72B is provided so as to extend rearward from the support ring portion 72A. The cam ring portion 72C is provided so as to extend radially outward from the rear end portion of the cylindrical portion 72B. The cam ball groove 72D is provided in the support ring portion 72A. At least a portion of the balls 73 is disposed in the cam ball groove 72D. The driven cam portion 72E is provided so as to protrude rearward from the rear surface of the cam ring portion 72C.

[0070] In the embodiment, three balls 73 are provided. Three cam ball grooves 72D are provided in the front part of the support ring portion 72A. In a plane perpendicular to the rotation axis CX, each of the three cam ball grooves 72D is arc-shaped. At least a part of the cam ball groove 72D is inclined in the front-rear direction. The cam ball groove 72D is provided so as to surround the rotation axis CX. One ball 73 is disposed in one cam ball groove 72D.

[0071] The spindle 9 has a spindle ball groove 9E. At least a portion of the balls 73 are disposed in the spindle ball groove 9E. Three spindle ball grooves 9E are provided on the outer circumferential surface of the spindle 9. Each of the three spindle ball grooves 9E has an arc shape in a plane perpendicular to the rotation axis CX. The spindle ball groove 9E is provided so as to surround the rotation axis CX. One ball 73 is disposed in one spindle ball groove 9E.

[0072] The compression spring 75 is disposed around the spindle 9. The compression spring 75 biases the clutch cam 72 and the spindle 9 forward. The compression spring 75 is disposed inside the cylindrical portion 72B of the clutch cam 72. The washer 76 and the ball 77 are disposed around the spindle 9 inside the cylindrical portion 72B of the clutch cam 72. A plurality of balls 77 are disposed around the spindle 9. The balls 77 contact the rear surface of the support ring portion 72A. The washer 76 is disposed behind the balls 77. The front end of the compression spring 75 contacts the rear surface of the washer 76. The rear end of the compression spring 75 is connected to the front end of the one-way needle bearing 80. The compression spring 75 biases the clutch cam 72 forward via the washer 76 and the ball 77. The spindle 9 is coupled to the clutch cam 72 via the ball 73. When the clutch cam 72 is urged forward by the compression spring 75, the spindle 9 is also urged forward together with the clutch cam 72.

[0073] The spindle 9 rotates by the rotational force of the motor 6. At least a portion of the spindle 9 is disposed forward of the power transmission mechanism 8. At least a portion of the spindle 9 is disposed forward of the drive gear 71. The spindle 9 rotates about a rotation axis CX while supporting the drive gear 71. The rotation axis AX of the motor 6 and the rotation axis CX of the spindle 9 are different. The rotation axis AX and the rotation axis CX are parallel. The spindle 9 rotates by the rotor 34. The spindle 9 rotates by the rotational force of the rotor 34 transmitted by the power transmission mechanism 8. The spindle 9 rotates while holding the driver bit 30, which is an end tool. The spindle 9 rotates about the rotation axis CX while the driver bit 30 is attached.

[0074] The spindle 9 has a rod portion 9A, a stopper portion 9B, a bit holding hole 9C, a hollow hole 9D, a spindle ball groove 9E, and a through hole 9F. The rod portion 9A is arranged to extend in the front-rear direction. The stopper portion 9B is provided so as to protrude radially outward from the front portion of the outer circumferential surface of the rod portion 9A. The bit holding hole 9C is provided so as to extend rearward from the front end surface of the rod portion 9A. The driver bit 30 is attached to the rod portion 9A. The driver bit 30 is inserted into the bit holding hole 9C from the front of the bit holding hole 9C. The cross section of the bit holding hole 9C perpendicular to the rotation axis CX is a regular hexagon. The hollow hole 9D is provided so as to extend forward from the rear end surface of the spindle 9. The hollow hole 9D reduces the weight of the spindle 9. An oil seal 63 is arranged around the rod portion 9A. The oil seal 63 is held in the cylindrical portion 32 B of the front housing 32 .

[0075] A rear portion of the spindle 9 is rotatably supported by a spindle rear bearing 62. Two spindle rear bearings 62 are arranged in the front-rear direction. The spindle rear bearings 62 are arranged rearward of the drive gear 71. A front portion of the spindle 9 is rotatably supported by a spindle front bearing 48.

[0076] Two spindle rear bearings 62 are arranged in the front-rear direction. Arranging two spindle rear bearings 62 suppresses axial vibration of the spindle 9. By suppressing axial vibration of the spindle 9, the pinion gear 47 and the drive gear 71 mesh properly.

[0077] The spindle front bearing 48 is held by the front housing 32. The front end surface of the outer ring of the spindle front bearing 48 is supported by a protrusion protruding radially inward from the inner circumferential surface of the cylindrical portion 32B of the front housing 32. The stopper portion 9B of the spindle 9 can contact the rear end surface of the outer ring of the spindle front bearing 48. The spindle 9 is rotatably supported by the spindle front bearing 48 forward of the drive gear 71. The spindle 9 is also supported by the front housing 32 forward of the drive gear 71 so as to be movable in the front-rear direction. The spindle 9 is supported by the gear housing 3 forward of the drive gear 71 via the spindle front bearing 48 so as to be movable in the front-rear direction. The spindle 9 is movable in the front-rear direction between a forward position and a backward position rearward of the forward position. The clutch cam 72 moves in the front-rear direction together with the spindle 9.

[0078] The driven cam portion 72E of the clutch cam 72 is disposed forward of the driving cam portion 71D of the driving gear 71. The driving cam portion 71D of the driving gear 71 and the driven cam portion 72E of the clutch cam 72 face each other. The spindle 9 is supported by the gear housing 3 via the spindle front bearing 48 so as to be movable in the front-rear direction so that the driving cam portion 71D and the driven cam portion 72E come into contact with each other or are separated from each other. The driven cam portion 72E moves in the front-rear direction together with the spindle 9 so as to come into contact with the driving cam portion 71D or be separated from the driving cam portion 71D. When the spindle 9 is disposed in the forward position, the driving cam portion 71D and the driven cam portion 72E are separated from each other. When the spindle 9 is disposed in the backward position, the driving cam portion 71D and the driven cam portion 72E are in a state in which they can come into contact with each other.

[0079] The tool holding mechanism 10 holds the driver bit 30 inserted in the bit holding hole 9C. The tool holding mechanism 10 includes a ball 49 arranged in a through hole 9F connecting the outer circumferential surface of the spindle 9 and the inner circumferential surface of the bit holding hole 9C, a ring 50 arranged radially outward of the ball 49 with respect to the rotation axis CX, and a spring 51 arranged outside the ring 50. The ball 49 is pressed radially inward by the spring 51 via the ring 50. At least a portion of the ball 49 is arranged in a recess 30A provided in the driver bit 30, thereby preventing the driver bit 30 from falling out of the bit holding hole 9C.

[0080] The lock ring 11 is operated by an operator to adjust the amount of protrusion of the driver bit 30 from the front end surface of the rubber cap 13. The lock ring 11 is disposed around the cylindrical portion 32B of the front housing 32. The lock ring 11 can rotate relative to the front housing 32. When the lock ring 11 is rotated, it moves in the front-to-rear direction relative to the front housing 32. When the lock ring 11 is rotated in one direction, the amount of protrusion of the driver bit 30 increases. When the lock ring 11 is rotated in the other direction, the amount of protrusion of the driver bit 30 decreases.

[0081] The adjust sleeve 12 is detachably attached to the lock ring 11. The adjust sleeve 12 is attached to the lock ring 11 via an O-ring 52. The adjust sleeve 12 is disposed around the spindle 9 forward of the lock ring 11. The adjust sleeve 12 is substantially cylindrical. The adjust sleeve 12 is tapered so that its diameter decreases toward the front. The adjust sleeve 12 moves in the front-rear direction together with the lock ring 11 as the lock ring 11 rotates.

[0082] The rubber cap 13 is attached to the front end of the adjusting sleeve 12. The rubber cap 13 is fixed to the front end of the adjusting sleeve 12. The rubber cap 13 is disposed around the driver bit 30 attached to the spindle 9. When a screw is fastened using the screwdriver 1, the rubber cap 13 comes into contact with the workpiece. The rubber cap 13 prevents the workpiece from being damaged.

[0083] The front end of the driver bit 30 inserted into the bit holding hole 9C and held by the tool holding mechanism 10 is positioned forward of the front end of the rubber cap 13. When adjusting the tightening depth of the screw into the workpiece, the operator rotates the lock ring 11 to move the lock ring 11 in the front-rear direction. As the lock ring 11 moves in the front-rear direction, the adjust sleeve 12 and the rubber cap 13 move in the front-rear direction together with the lock ring 11. This adjusts the amount of protrusion of the driver bit 30 from the front end face of the rubber cap 13. As the amount of protrusion of the driver bit 30 from the front end face of the rubber cap 13 is adjusted, the tightening depth of the screw into the workpiece is adjusted.

[0084] The trigger lever 14 is operated by an operator to start the motor 6. The trigger lever 14 is provided on the grip portion 22A. The trigger lever 14 protrudes forward from the front part of the upper part of the grip portion 22A. A switch 54 is disposed behind the trigger lever 14. The switch 54 is housed in the grip portion 22A. The trigger lever 14 is connected to the switch 54. When the trigger lever 14 is pulled so as to move rearward, an operation signal is output from the switch 54 to the controller 20. The controller 20 drives the motor 6 based on the operation signal from the switch 54. When the operation of the trigger lever 14 is released, the motor 6 is stopped.

[0085] The lock button 15 is operated by an operator to maintain the trigger lever 14 in a pulled state. The lock button 15 is provided on the upper left part of the grip part 22A. By pressing the lock button 15 while the trigger lever 14 is pulled, the trigger lever 14 is maintained in a pulled state even if the operator releases the trigger lever 14, and the drive of the motor 6 is maintained.

[0086] The forward / reverse switching lever 16 is operated by an operator to switch the rotation direction of the motor 6. The forward / reverse switching lever 16 is provided on the connecting portion 22B. By operating the forward / reverse switching lever 16, the rotation direction of the motor 6 is switched from one of the forward direction and the reverse direction to the other. By switching the rotation direction of the motor 6, the rotation direction of the spindle 9 is switched. When the forward / reverse switching lever 16 is placed in the neutral position, the trigger lever 14 cannot be operated.

[0087] The light 17 emits illumination light. The light 17 includes a light emitting diode (LED). The light 17 is disposed in the front part of the lower part of the connecting part 24. The light 17 illuminates the front of the spindle 9 with illumination light.

[0088] The switch plate 18 has a mode switching button 18A operated by an operator. The switch plate 18 is provided on the battery holding portion 23. The switch plate 18 is provided on the upper surface of the battery holding portion 23 between the lower end of the grip portion 22A and the lower end of the connecting portion 24. The operation mode of the motor 6 is switched by the operator operating the mode switching button 18A. In the embodiment, the operation modes of the motor 6 include a normal mode and a push drive mode. The normal mode refers to an operation mode in which the motor 6 is started by pulling the trigger lever 14. The push drive mode refers to an operation mode in which the motor 6 is not driven immediately even when the trigger lever 14 is pulled, and the motor 6 is started after it is detected that the spindle 9 together with the driver bit 30 has moved backward from the forward position. The operator can set the operation mode of the screwdriver 1 to either the normal mode or the push drive mode (also called Auto Start) by operating the mode switching button 18A.

[0089] The bit position detection unit 19 operates to detect when the spindle 9 together with the driver bit 30 has moved backward from the forward position when the operation mode of the motor 6 is set to the push drive mode.

[0090] The bit position detection unit 19 has a bearing 90 , a moving member 91 , a magnet 92 , and a mode sensor board 93 .

[0091] The bearing 90 is disposed around the cylindrical portion 72B of the clutch cam 72. The bearing 90 supports the clutch cam 72 so that it can rotate.

[0092] The moving member 91 is disposed around the spindle 9. The bearing 90 is disposed between the spindle 9 and the moving member 91. In the embodiment, the moving member 91 is disposed around the clutch cam 72. The bearing 90 is disposed between the clutch cam 72 and the moving member 91. The moving member 91 is connected to the clutch cam 72 via the bearing 90.

[0093] As described above, the spindle 9 can move in the front-rear direction between the forward position and the backward position. The clutch cam 72 moves in the front-rear direction together with the spindle 9. The moving member 91 and the bearing 90 move in the front-rear direction together with the spindle 9 and the clutch cam 72. That is, the spindle 9, the clutch cam 72, the bearing 90, and the moving member 91 move together in the front-rear direction relative to the front housing 32. The clutch cam 72 is disposed on the front side of the motor 6 and is a push-in clutch driven by the motor 6. The spindle 9 is disposed on the front side of the clutch cam 72, which is a push-in clutch, and is driven by the clutch cam 72. As shown in FIG. 5, an accommodating recess 31D is provided at the rear of the recess 31B of the rear housing 31 to accommodate the rear end of the spindle 9 that has moved to the backward position.

[0094] The moving member 91 has a ring portion 91A arranged around the bearing 90 and a protruding portion 91B protruding downward from the ring portion 91A. As shown in FIG. 8, a recess 32G is provided on the inner peripheral surface of the front housing 32. The protruding portion 91B is arranged in the recess 32G. By arranging the protruding portion 91B in the recess 32G, the relative rotation between the moving member 91 and the front housing 32 is suppressed. That is, the moving member 91 is prevented from rotating by the protruding portion 91B and the recess 32G. The protruding portion 91B and the recess 32G function as a rotation prevention mechanism that suppresses the rotation of the moving member 91 relative to the front housing 32. The clutch cam 72 is rotatably supported by the moving member 91 via the bearing 90. The clutch cam 72 and the spindle 9 are rotatable relative to the moving member 91 and the front housing 32. The recess 32G is provided to extend in the front-rear direction. The protruding portion 91B is movable in the front-rear direction inside the recess 32G. The recess 32G functions as a guide portion that guides the moving member 91 in the front-rear direction.

[0095] The magnet 92 is disposed forward of the spindle rear bearing 62. The magnet 92 is disposed forward of the drive gear 71. The magnet 92 moves in the front-rear direction in synchronization with the spindle 9. In the embodiment, the magnet 92 is fixed to a convex portion 91B of the moving member 91. The magnet 92 may be embedded inside the moving member 91. In the front-rear direction, the position of the magnet 92 and the position of at least a part of the spindle 9 are equal. The magnet 92 moves in the front-rear direction together with the moving member 91.

[0096] The mode sensor board 93 includes a circuit board. A magnetic sensor 94 is mounted on the mode sensor board 93. The magnetic sensor 94 detects the magnet 92. The mode sensor board 93 including the magnetic sensor 94 is disposed radially outward of the rotation axis CX. The mode sensor board 93 is disposed forward of the spindle rear bearing 62. The mode sensor board 93 is disposed forward of the drive gear 71. In the front-rear direction, the position of the mode sensor board 93 and the position of at least a part of the spindle 9 are equal. At least a part of the mode sensor board 93 faces the magnet 92 fixed to the moving member 91. The mode sensor board 93 is supported by the main body housing 2. Since the mode sensor board 93 is disposed outside (below) the front housing 32, the grease applied to the spindle 9, the drive gear 71, the clutch cam 72, etc. is prevented from adhering to the mode sensor board 93. In addition, the heat generated by the spindle 9, the drive gear 71, the clutch cam 72, etc. is prevented from being transmitted to the mode sensor board 93. This prevents the mode sensor board 93 including the magnetic sensor 94 from being deteriorated or broken. The mode sensor board 93 may be supported by the front housing 32.

[0097] The mode sensor board 93 is disposed below the magnet 92. The magnetic sensor 94 is mounted on the lower surface of the mode sensor board 93. In the embodiment, the magnetic sensor 94 is covered with a resin layer 95. As shown in FIG. 6, a recess 2A is provided in at least a part of the main body housing 2. The mode sensor board 93 including the resin layer 95 is fitted into the recess 2A. The magnetic sensor 94 may be mounted on the upper surface of the mode sensor board 93. The resin layer 95 may be omitted.

[0098] The magnetic sensor 94 detects the movement state of the moving member 91 by detecting a change in the magnetic field of the magnet 92. A detection signal from the magnetic sensor 94 is transmitted to the controller 20 via a lead wire 96. The magnetic sensor 94 is disposed radially outside the clutch cam 72, which is a push-in clutch, and functions as a push-in sensor that detects when the clutch cam 72 is pushed in.

[0099] The controller 20 outputs a control signal for controlling the motor 6. The controller 20 is housed in the battery holding section 23. The controller 20 controls the motor 6 based on the operation mode of the motor 6 set by operating the mode switching button 18A. The controller 20 includes a circuit board 20A on which a plurality of electronic components are mounted, and a case 20B that houses the circuit board 20A. Examples of the electronic components mounted on the circuit board 20A include a processor such as a CPU (Central Processing Unit), a non-volatile memory such as a ROM (Read Only Memory) or storage, a volatile memory such as a RAM (Random Access Memory), at least six switching elements, a transistor, and a resistor.

[0100] The controller 20 controls the motor 6 based on the detection signal of the magnetic sensor 94. In the normal mode, the controller 20 starts the motor 6 by receiving an operation signal that the trigger lever 14 is pulled. In the push drive mode, the controller 20 starts the motor 6 by receiving an operation signal that the trigger lever 14 is pulled and also by receiving a detection signal from the magnetic sensor 94 that detects that the moving member 91 has moved backward and the magnet 92 has moved relative to the mode sensor board 93.

[0101] [Clutch mechanism] The clutch mechanism 8A transmits the rotational force of the rotor 34 of the motor 6 to the spindle 9 when the spindle 9 moves to the retracted position during forward rotation of the motor 6. The clutch mechanism 8A includes a drive cam portion 71D provided on the drive gear 71, and a driven cam portion 72E provided on the clutch cam 72 so as to face the drive cam portion 71D. The clutch cam 72 is disposed around the spindle 9. The clutch cam 72 is coupled to the spindle 9 via a ball 73. The clutch mechanism 8A also has a compression spring 75 that biases the clutch cam 72 and the spindle 9 forward.

[0102] When performing a screw tightening operation on a workpiece, the forward / reverse switching lever 16 is operated so that the rotor 34 of the motor 6 rotates forward. After the driver bit 30 is inserted into the bit holding hole 9C and attached to the rod portion 9A, the operator grasps the handle portion 22 and inserts the tip of the driver bit 30 into the cross groove in the head of the screw that is in contact with the surface of the workpiece. Next, the operator pulls the trigger lever 14.

[0103] <Normal mode> The operation of the screwdriver 1 in the normal mode will be described below. In the normal mode, the motor 6 is started by pulling the trigger lever 14. When the motor 6 is started and the rotor 34 rotates in the normal direction, the rotation of the rotor shaft 41 is transmitted to the drive gear 71 via the pinion gear 47, and the drive gear 71 rotates. When the rotor 34 rotates in the normal direction, the drive gear 71 and the spindle 9 rotate relative to each other due to the action of the one-way needle bearing 80 disposed between the drive gear 71 and the spindle 9. In other words, when the rotor 34 rotates in the normal direction, even if the drive gear 71 rotates, the spindle 9 does not rotate due to the action of the one-way needle bearing 80.

[0104] When the rotor 34 rotates in the forward direction and the spindle 9 is positioned in the forward position, even if the drive gear 71 rotates, the drive cam portion 71D and the driven cam portion 72E are separated from each other, so that no rotational force is transmitted from the drive gear 71 to the clutch cam 72.

[0105] While the drive gear 71 is rotating, the operator grasps the handle portion 22 and performs a pushing operation to push the screwdriver 1 so that the screwdriver 1 approaches the workpiece. By pushing the screwdriver 1, the spindle 9 together with the driver bit 30 moves backward against the elastic force of the compression spring 75.

[0106] When the spindle 9 moves to the retreat position, the drive cam portion 71D and the driven cam portion 72E come into contact with each other. When the spindle 9 moves from the advance position to the retreat position and the drive cam portion 71D and the driven cam portion 72E come into contact with each other, the clutch cam 72 receives a resistance force in the rotational direction from the spindle 9, and as a result, the ball 73 rolls between the spindle ball groove 9E and the cam ball groove 72D, and the spindle 9 and the clutch cam 72 rotate relatively via the ball 73. The ball 73 moves from one end to the other end of the cam ball groove 72D in the circumferential direction and stops at the other end of the cam ball groove 72D, so that the spindle 9 and the clutch cam 72 can rotate together. In the embodiment, at least a part of the cam ball groove 72D is inclined in the front-rear direction, so that the drive cam portion 71D comes into contact with the driven cam portion 72E, and the spindle 9 and the clutch cam 72 rotate relatively via the ball 73, and the clutch cam 72 moves backward.

[0107] When the motor 6 is driven with the spindle 9 and clutch cam 72 moving backward and the drive cam portion 71D and the driven cam portion 72E in contact with each other, the spindle 9 and clutch cam 72 rotate based on the rotation of the drive gear 71. The spindle 9 rotates due to the rotational force of the drive gear 71 transmitted via the clutch mechanism 8A including the drive cam portion 71D and the driven cam portion 72E. The driver bit 30 rotates forward together with the spindle 9, and the screw is screwed into the workpiece.

[0108] In the screw tightening operation, the operator continues to push the screwdriver 1. As the screw tightening operation progresses, the screwdriver 1 gradually approaches the workpiece, and eventually the front end of the rubber cap 13 comes into contact with the workpiece. After the front end of the rubber cap 13 comes into contact with the workpiece, the spindle 9 rotates and moves forward as the screw tightening operation progresses. At the beginning of the screw tightening operation, the torque applied from the screw to the spindle 9 via the driver bit 30 is large, but at the end of the screw tightening operation, the torque applied from the screw to the spindle 9 via the driver bit 30 decreases. When the torque applied to the spindle 9 via the driver bit 30 decreases, the contact force between the drive cam portion 71D and the driven cam portion 72E decreases. When the contact force between the drive cam portion 71D and the driven cam portion 72E decreases, the clutch cam 72 moves forward due to the biasing force of the compression spring 75. As a result, the driving cam portion 71D and the driven cam portion 72E move away from each other, stopping the rotation of the spindle 9. This completes the screw tightening operation.

[0109] Even if the driving cam portion 71D and the driven cam portion 72E separate and the rotation of the spindle 9 stops, the motor 6 continues to drive as long as the trigger lever 14 is being pulled. The motor 6 stops when the operation of the trigger lever 14 is released. When the pushing action is released and the driver bit 30 is separated from the screw, the spindle 9 returns to the forward position by the biasing force of the compression spring 75.

[0110] <Push drive mode> Next, the operation of the screwdriver 1 in the push drive mode will be described. In the push drive mode, the motor 6 does not start just by pulling the trigger lever 14. When the spindle 9 moves backward by pushing the screwdriver 1 while the trigger lever 14 is pulled, the moving member 91 moves backward together with the spindle 9. When the moving member 91 moves backward, the magnet 92 moves relative to the mode sensor board 93. The controller 20 starts the motor 6 based on the change in the magnetic field detected by the magnetic sensor 94 of the mode sensor board 93. When the motor 6 starts, the drive gear 71 starts to rotate. As the pushing operation continues, the spindle 9 moves toward the retreated position. When the spindle 9 moves to the retreated position and the drive cam portion 71D comes into contact with the driven cam portion 72E, the spindle 9 rotates by the rotational force of the drive gear 71 transmitted via the clutch mechanism 8A including the drive cam portion 71D and the driven cam portion 72E. The driver bit 30 rotates in the normal direction together with the spindle 9, whereby the screw is screwed into the workpiece.

[0111] As the screw tightening operation progresses, the screwdriver 1 gradually approaches the workpiece, and eventually the front end of the rubber cap 13 comes into contact with the workpiece. When the torque applied to the spindle 9 via the driver bit 30 decreases, the clutch cam 72 moves forward due to the biasing force of the compression spring 75. This causes the drive cam portion 71D and the driven cam portion 72E to separate from each other, and the rotation of the spindle 9 stops. This completes the screw tightening operation.

[0112] When the screw tightening operation is completed, the pushing action is released, and the driver bit 30 is released from the screw, the spindle 9 returns to the forward position due to the biasing force of the compression spring 75. When the spindle 9 returns to its forward position, the moving member 91 and the magnet 92 also return to their forward positions. The controller 20 stops the motor 6 based on the change in the magnetic field detected by the magnetic sensor 94 of the mode sensor board 93.

[0113] [Spindle lock mechanism] The spindle lock mechanism 8B transmits the rotational force of the rotor 34 of the motor 6 to the spindle 9 when the motor 6 rotates in the reverse direction. The spindle lock mechanism 8B includes a one-way needle bearing 80 arranged around the spindle 9. When the rotor 34 rotates in the reverse direction, the drive gear 71 and the spindle 9 are locked by the one-way needle bearing 80. That is, the one-way needle bearing 80 locks the drive gear 71 and the spindle 9 to prevent the drive gear 71 and the spindle 9 from rotating relative to each other. When the rotor 34 rotates in the reverse direction, the drive gear 71 and the spindle 9 rotate together without rotating relative to each other. Since the drive gear 71 and the spindle 9 rotate together when the rotor 34 rotates in the reverse direction, the rotation of the drive gear 71 is transmitted to the spindle 9 even if the drive cam portion 71D and the driven cam portion 72E are separated from each other. When performing a screw removal operation to remove a screw from a workpiece, the motor 6 is reversed. In the unscrewing operation, the spindle 9 can rotate even if the spindle 9 does not move from the forward position to the backward position. In other words, the spindle 9 rotates even if a pushing action of pushing the screwdriver 1 so that the screwdriver 1 approaches the workpiece is not performed.

[0114] [effect] As described above, in the embodiment, the screwdriver 1 includes the gear housing 3, the motor 6, the pinion gear 47 rotated by the motor 6, the drive gear 71 which rotates about the rotation axis CX as the first rotation axis while meshing with the pinion gear 47, the spindle 9 which is supported on the gear housing 3 forward of the drive gear 71 so as to be movable in the front-rear direction and which is rotatable about the rotation axis CX with the driver bit 30 as the tip tool attached thereto, the drive cam portion 71D which rotates about the rotation axis CX by the drive gear 71, and the drive cam portion 71D which is disposed forward of the drive cam portion 71D and which comes into contact with or moves against the drive cam portion 71D. the spindle 9 being a support shaft which rotates about the rotation axis CX while supporting the drive gear 71; a spindle rear bearing 62 being a first bearing which is arranged rearward of the drive gear 71 and rotatably supports the spindle 9; a magnet 92 which is arranged forward of the spindle rear bearing 62 and which moves in the front-rear direction in synchronization with the spindle 9; a magnetic sensor 94 which is arranged radially outward of the rotation axis CX and detects the magnet 92; and a controller 20 which controls the motor 6 based on the detection signal of the magnetic sensor 94.

[0115] In the above configuration, the magnet 92 and the magnetic sensor 94 are disposed forward of the spindle rear bearing 62, which prevents the overall length of the screwdriver 1 from becoming long. The overall length of the screwdriver 1 refers to the distance in the front-rear direction between the rear end of the motor 6 and the front end of the spindle 9. Note that the overall length of the screwdriver 1 may also be the distance in the front-rear direction between the rear end of the motor 6 and the front end of the rubber cap 13.

[0116] In this embodiment, the magnet 92 is disposed forward of the drive gear 71 .

[0117] In the above configuration, the magnet 92 and the magnetic sensor 94 are disposed forward of the drive gear 71, so that the overall length of the screwdriver 1 is prevented from becoming long.

[0118] In this embodiment, the position of the magnet 92 and the position of at least a part of the spindle 9 are equal in the front-rear direction.

[0119] In the above configuration, the position of the magnet 92 and the position of at least a part of the spindle 9 are the same in the front-rear direction, so that the overall length of the screwdriver 1 is prevented from becoming long.

[0120] In the embodiment, the screwdriver 1 includes a moving member 91 that is disposed around the spindle 9 and moves in the forward and backward directions together with the spindle 9. A magnet 92 is fixed to the moving member 91.

[0121] In the above configuration, the magnet 92 is moved in the front-rear direction together with the spindle 9.

[0122] In an embodiment, the screwdriver 1 includes a bearing 90, which is a second bearing arranged between the spindle 9 and the movable member 91, and a rotation prevention mechanism including a convex portion 91B and a concave portion 32G that suppresses rotation of the movable member 91 relative to the gear housing 3.

[0123] In the above configuration, since the moving member 91 does not rotate, the magnetic sensor 94 can properly detect the magnet 92 fixed to the moving member 91. In addition, the bearing 90 allows the spindle 9 to rotate.

[0124] In the embodiment, the screwdriver 1 includes a clutch cam 72 that is disposed around the spindle 9, is coupled to the spindle 9 via a ball 73, and is provided with a driven cam portion 72E. A moving member 91 is disposed around the clutch cam 72. A bearing 90 is disposed between the clutch cam 72 and the moving member 91.

[0125] In the above-described configuration, the spindle 9, the clutch cam 72, the bearing 90, and the moving member 91 to which the magnet 92 is fixed are moved together in the front-rear direction, so that the structure is prevented from becoming complicated.

[0126] In the embodiment, the screwdriver 1 includes a recess 32G that functions as a guide portion for guiding the moving member 91 in the front-rear direction.

[0127] In the above configuration, the moving member 91 can move appropriately in the front-rear direction.

[0128] In the embodiment, the drive cam portion 71D is provided on the drive gear 71.

[0129] With the above configuration, an increase in the number of parts of the screwdriver 1 is suppressed.

[0130] In an embodiment, the screwdriver 1 includes a motor 6, a clutch cam 72 which is a push-in clutch arranged forward of the motor 6 and driven by the motor 6, a spindle 9 which is arranged forward of the clutch cam 72 and driven by the clutch cam 72, a magnetic sensor 74 which is a push-in sensor arranged radially outside the clutch cam 72 and detects when the clutch cam 72 is pushed in, and a battery pack 25 which is a battery for supplying power to the motor 6.

[0131] In the above configuration, the magnetic sensor 94, which is a push-in magnetic sensor, is disposed radially outside the clutch cam 72, which is a push-in clutch, so that the overall length of the screwdriver 1 is prevented from becoming long.

[0132] The magnetic sensor 94 may be directly or indirectly fixed to the clutch cam 72. When the magnetic sensor 94 is indirectly fixed to the clutch cam 72, it is fixed via one or more other members. In any case, it is sufficient that the magnetic sensor 94 is disposed on the radial outside of the clutch cam 72. The magnetic sensor 94 is disposed between the front end and the rear end of the clutch cam 72.

[0133] [Other embodiments] Fig. 12 is a vertical cross-sectional view showing a main part of a screwdriver according to a modified example. As shown in Fig. 12, a mode sensor board 93 including a magnetic sensor 94 may be disposed forward of the spindle front bearing 48. Also, a magnet 92A may be disposed forward of the spindle front bearing 48.

[0134] FIG. 13 is a vertical cross-sectional view showing a main part of a screwdriver according to a modified example. In the above-mentioned embodiment, the spindle 9 includes a support shaft. As shown in FIG. 13, the drive gear 710 may be supported by a support shaft 730 different from the spindle 900. At least a part of the spindle 900 is disposed forward of the support shaft 730. In addition, the clutch cam 720 may be coupled to the drive gear 710. The rear end of the support shaft 730 is rotatably supported by a bearing 620. The spindle 900 is rotatably supported by a spindle bearing 480. The spindle 900 is biased forward by a compression spring 750. The mode sensor board 93 including the magnetic sensor 94 is disposed forward of the bearing 620. The mode sensor board 93 including the magnetic sensor 94 may be disposed forward of the drive gear 710. In the example shown in FIG. 13, the mode sensor board 93 including the magnetic sensor 94 is disposed radially outward of the support shaft 730. The magnet 92B is disposed around the rear end of the spindle 900. The magnetic sensor 94 detects the magnet 92B. In the front-rear direction, the position of the magnetic sensor 94 and the position of at least a part of the support shaft 730 are the same. In addition, in the front-rear direction, the position of the magnet 92B and the position of at least a part of the support shaft 730 may be the same.

[0135] In the above-described embodiment, the spindle 9 and the magnet 92 move together in the front-rear direction. For example, the movement of the magnet 92 may start after the movement of the spindle 9 starts. Furthermore, the movement distance of the spindle 9 and the movement distance of the magnet 92 may be equal to or different from each other. Furthermore, when the spindle 9 moves backward, the magnet 92 may move forward. The magnet 92 may move in synchronization with the spindle 9.

[0136] In the above embodiment, the push-in sensor that detects that the clutch cam 72, which is a push-in clutch, has been pushed in is a magnetic sensor 94 (hall element) that detects a magnet (92, etc.). The push-in sensor is not limited to the magnetic sensor 94 as long as it can detect that the clutch cam 72 has been pushed in. Any non-contact sensor can be used as the push-in sensor. The push-in sensor may also be a contact switch. For example, a switch such as a tact switch may be pushed into the clutch cam 72 to detect that the clutch cam 72 has been pushed in.

[0137] In the above-described embodiment, the power source for the screwdriver 1 does not have to be the battery pack 25, and may be a commercial power source (AC power source). [Explanation of symbols]

[0138] 1...screwdriver, 2...main body housing, 2A...recess, 2L...left housing, 2R...right housing, 2S...screw, 3...gear housing, 3S...screw, 4...cover, 4A...first cover part, 4B...second cover part, 4C...third cover part, 4D...fourth cover part, 5...battery mounting part, 6...motor, 7...fan, 8...power transmission mechanism, 8A...clutch mechanism, 8B...spindle lock mechanism, 9...spindle, 9A...rod part, 9B...stopper part, 9C...bit holding hole, 9D...hollow hole, 9E...spindle ball groove, 9F...through hole, 10...tool holding mechanism, 11...ro locking ring, 12...adjustment sleeve, 13...rubber cap, 14...trigger lever, 15...lock button, 16...forward / reverse switching lever, 17...light, 18...switch plate, 18A...mode switching button, 19...bit position detection section, 20...controller, 20A...circuit board, 20B...case, 21...motor housing section, 21A...recess, 22...handle section, 22A...grip section, 22B...connecting section, 23...battery holding section, 24...connecting section, 25...battery pack, 26...intake port, 27...exhaust port, 29...sleeve, 30...driver bit, 30A...recess, 31...rear side housing, 31A...plate portion, 31B...recess, 31C...tubular portion, 31D...accommodating recess, 32...front housing, 32A...plate portion, 32B...tubular portion, 32G...recess, 33...stator, 34...rotor, 35...stator core, 36F...front insulator, 36R...rear insulator, 37...coil, 38...short-circuit member, 39...connector, 39S...screw, 40...rotor core, 41...rotor shaft, 42...rotor magnet, 43...rotation sensor board, 43S...screw, 44...rotor bearing, 45...rotor bearing, 46...circlip, 47...pinion gear , 48... spindle front bearing, 49... ball, 50... ring, 51... spring, 52... O-ring, 54... switch, 62... spindle rear bearing (first bearing), 63... oil seal, 71... drive gear, 71A... ring portion, 71B... gear portion, 71C... cylindrical portion, 71D... drive cam portion, 72... clutch cam, 72A... support ring portion, 72B... cylindrical portion, 72C... cam ring portion, 72D... cam ball groove, 72E... driven cam portion, 73... ball, 75... compression spring, 76... washer, 77... ball, 80... one-way needle bearing,90...bearing (second bearing), 91...moving member, 91A...ring portion, 91B...projection portion, 92...magnet, 92A...magnet, 92B...magnet, 93...mode sensor board, 94...magnetic sensor, 95...resin layer, 96...lead wire, 480...spindle bearing, 620...bearing, 710...driving gear, 720...clutch cam, 730...support shaft, 750...compression spring, 900...spindle, AX...rotating shaft, CX...rotating shaft (first rotating shaft).

Claims

1. A housing, a motor, a pinion gear rotated by the motor, a drive gear that rotates about a first rotation axis in a state of meshing with the pinion gear, a spindle that is supported by the housing so as to be movable in the front-rear direction in front of the drive gear and that can rotate about the first rotation axis with a tip tool attached thereto, a drive cam portion that rotates about the first rotation axis by the drive gear, a driven cam portion that is disposed in front of the drive cam portion and that moves in the front-rear direction together with the spindle so as to contact or be separated from the drive cam portion, a support shaft that rotates about the first rotation axis while supporting the drive gear, a first bearing that is disposed behind the drive gear and that rotatably supports the support shaft, a magnet that is disposed in front of the first bearing and that moves in the front-rear direction in synchronization with the spindle, a magnetic sensor that is disposed outside the radial direction of the first rotation axis and that detects the magnet, and a controller that controls the motor based on a detection signal of the magnetic sensor. A screwdriver.

2. The magnet is disposed in front of the drive gear. The screwdriver according to claim 1.

3. In the front-rear direction, a position of the magnet and a position of at least a part of the spindle are equal. The screwdriver according to claim 1.

4. A moving member that is disposed around the spindle and that moves in the front-rear direction together with the spindle is provided, and the magnet is fixed to the moving member. The screwdriver according to claim 1.

5. A second bearing that is disposed between the spindle and the moving member, and a rotation prevention mechanism that suppresses rotation of the moving member with respect to the housing are provided. The screwdriver according to claim 4.

6. A clutch cam that is disposed around the spindle, that is coupled to the spindle via balls, and that is provided with the driven cam portion is provided, the moving member is disposed around the clutch cam, and the second bearing is disposed between the clutch cam and the moving member. The screwdriver according to claim 5.

7. A guide portion that guides the moving member in the front-rear direction is provided. The screwdriver according to claim 4.

8. The spindle includes the support shaft. The screwdriver according to claim 1.

9. The drive cam portion is provided on the drive gear, The screwdriver according to claim 1.

10. A motor, A push clutch disposed on the front side of the motor and driven by the motor, A spindle disposed on the front side of the push clutch and driven by the push clutch, A push sensor disposed radially outside the push clutch for detecting that the push clutch has been pushed in, A battery for supplying power to the motor, and A screwdriver.

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