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 in this specification relates to a screwdriver.

Background Art

[0002] In the technical field related to screwdrivers, a screwdriver having 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

Summary of the Invention

Problems to be Solved by the Invention

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

[0005] The technology disclosed in this specification aims to suppress the increase in the overall length of a screwdriver provided with a push drive mechanism.

Means for Solving the Problems

[0006] This specification discloses a screwdriver. The screwdriver may include a housing, a motor, a pinion gear rotated by the motor, a drive gear that rotates around a first rotation axis while meshed with the pinion gear, a spindle that is supported in the housing in front of the drive gear so as to be movable in the front-rear direction and is rotatable around the first rotation axis with a cutting tool attached, a drive cam portion that rotates around the first rotation axis by the drive gear, a driven cam portion that is positioned in front of the drive cam portion and moves in the front-rear direction together with the spindle so as to contact or separate from the drive cam portion, a support shaft that rotates around the first rotation axis while supporting the drive gear, a first bearing positioned behind the drive gear and rotatably supporting the support shaft, a magnet positioned in front of the first bearing and moving in the front-rear direction in synchronization with the spindle, a magnetic sensor positioned radially outward of the first rotation axis and detecting the magnet, and a controller that controls the motor based on the detection signal of the magnetic sensor. [Effects of the Invention]

[0007] The technology disclosed herein suppresses the increase in the overall length of a screwdriver equipped with a push-drive mechanism. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a front perspective view showing a screwdriver according to an embodiment. [Figure 2] Figure 2 is a rear perspective view showing a screwdriver according to an embodiment. [Figure 3] Figure 3 is a side view showing a screwdriver according to an embodiment. [Figure 4] Figure 4 is a longitudinal cross-sectional view showing a screwdriver according to an embodiment. [Figure 5] Figure 5 is an enlarged longitudinal cross-sectional view of a part of the screwdriver according to the embodiment. [Figure 6] Figure 6 is an enlarged longitudinal cross-sectional view of the main part of the screwdriver according to the embodiment. [Figure 7] Figure 7 is a cross-sectional view showing a part of a screwdriver according to an embodiment. [Figure 8] Figure 8 is a cross-sectional view showing a screwdriver according to an embodiment. [Figure 9] Figure 9 is a cross-sectional view showing a screwdriver according to an embodiment. [Figure 10] Figure 10 is an exploded perspective view from the front showing the main components of the screwdriver according to this embodiment. [Figure 11] Figure 11 is an exploded perspective view from the rear showing the main components of the screwdriver according to the embodiment. [Figure 12] Figure 12 is a longitudinal cross-sectional view showing the main parts of a modified screwdriver. [Figure 13] Figure 13 is a longitudinal cross-sectional view showing the main parts of a modified screwdriver. [Modes for carrying out the invention]

[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 around a first rotation axis while meshed with the pinion gear, a spindle that is supported in the housing forward of the drive gear so as to be movable in the front-rear direction and is rotatable around the first rotation axis with a cutting tool attached, a drive cam portion that rotates around the first rotation axis by the drive gear, a driven cam portion that is positioned forward of the drive cam portion and moves in the front-rear direction together with the spindle so as to contact or separate from the drive cam portion, a support shaft that rotates around the first rotation axis while supporting the drive gear, a first bearing positioned behind the drive gear and rotatably supporting the support shaft, a magnet positioned forward of the first bearing and moving in the front-rear direction in synchronization with the spindle, a magnetic sensor positioned radially outward of the first rotation axis and detecting the magnet, and a controller that controls the motor based on the detection signal of the magnetic sensor.

[0010] In the above configuration, since the magnet and the magnetic sensor are arranged in front of the first bearing, an increase in the overall length of the screw driver is suppressed. The overall length of the screw driver refers to the distance in the front-rear direction between the rear end portion of the motor and the front end portion of the spindle. Incidentally, the overall length of the screw driver may be the distance in the front-rear direction between the rear end portion of the motor and the front end portion of a rubber cap described later.

[0011] In one or more embodiments, the magnet may be arranged in front of the drive gear.

[0012] In the above configuration, since the magnet and the magnetic sensor are arranged in front of the drive gear, an increase in the overall length of the screw driver is suppressed.

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

[0014] In the above configuration, in the front-rear direction, since the position of the magnet and at least a part of the position of the spindle are equal, an increase in the overall length of the screw driver is suppressed.

[0015] In one or more embodiments, the screw driver may include a moving member that is arranged around the spindle and moves in the front-rear direction together with the spindle. The magnet may be fixed to the moving member.

[0016] In the above configuration, the magnet is moved in the front-rear direction together with the spindle.

[0017] In one or more embodiments, the screw driver may include a second bearing arranged between the spindle and the moving member, and a rotation prevention mechanism that suppresses rotation of the moving member with respect 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. Furthermore, the spindle can rotate thanks to the second bearing.

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

[0020] In the above configuration, the spindle, clutch cam, second bearing, and the movable member to which the magnet is fixed move together in the front-rear direction, thus suppressing structural complexity.

[0021] In one or more embodiments, the screwdriver may include a guide portion that guides the moving member in the front-rear direction.

[0022] In the above configuration, the movable member can move appropriately in the front-to-back direction.

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

[0024] The above configuration suppresses the increase in the number of parts in the screwdriver.

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

[0026] The above configuration suppresses the increase in the number of parts in the screwdriver.

[0027] In one or more embodiments, the screwdriver may include a motor, a push clutch located in front of the motor and driven by the motor, a spindle located in front of the push clutch and driven by the push clutch, a push sensor located radially outward of the push clutch for detecting when the push clutch is pressed, and a battery for supplying power to the motor.

[0028] In the above configuration, the push-in magnetic sensor is positioned radially outward of the push-in clutch, which suppresses an increase in the overall length of the screwdriver.

[0029] The embodiments will be described below with reference to the drawings. The components of the embodiments described below can be combined as appropriate. In addition, some components may be omitted.

[0030] In the embodiments, the terms left, right, front, rear, top, and bottom are used to describe the positional relationships of each part. These terms indicate relative positions or directions with respect to the center of the screwdriver 1. In the embodiments, the screwdriver 1 has a spindle 9 that rotates around a rotation axis CX.

[0031] In this embodiment, the direction parallel to the rotation axis CX is appropriately referred to as the axial direction, the direction circumferentially 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] In the axial direction, the direction or position moving away from the center of the screwdriver 1 in a specified direction shall be appropriately referred to as the "one axial side," and the opposite side of the "one axial side" shall be appropriately referred to as the "other axial side." In the circumferential direction, the specified direction shall be appropriately referred to as the "one circumferential side," and the opposite side of the "one circumferential side" shall be appropriately referred to as the "other circumferential side." In the radial direction, the direction or position moving away from the rotation axis AX shall be appropriately referred to as the "radial outer side," and the opposite side of the "radial outer side" shall be appropriately referred to as the "radial inner side."

[0033] In this embodiment, the axial direction and the front-rear direction coincide. One side of the axial direction may be considered the front. The other side of the axial direction may be considered the rear.

[0034] [Screwdriver] Figure 1 is a front perspective view showing a screwdriver 1 according to an embodiment. Figure 2 is a rear perspective view showing a screwdriver 1 according to an embodiment. Figure 3 is a side view showing a screwdriver 1 according to an embodiment. Figure 4 is a longitudinal cross-sectional view showing a screwdriver 1 according to an embodiment. Figure 5 is an enlarged longitudinal cross-sectional view of a part of the screwdriver 1 according to an embodiment. Figure 6 is an enlarged longitudinal cross-sectional view of the main part of the screwdriver 1 according to an embodiment. Figure 7 is a transverse cross-sectional view showing a part of the screwdriver 1 according to an embodiment. Figure 8 is a cross-sectional view showing a screwdriver 1 according to an embodiment, corresponding to the view taken along line AA in Figure 5. Figure 9 is a cross-sectional view showing a screwdriver 1 according to an embodiment, corresponding to the view taken along line BB in Figure 5. Figure 10 is an exploded front perspective view showing the main part of the screwdriver 1 according to an embodiment. Figure 11 is an exploded rear perspective view showing the main part 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 housing 2 accommodates at least some of the components of the screwdriver 1. The main housing 2 is composed of a pair of split housings. The main 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 fastened together by a number of screws 2S.

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

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

[0039] The handle portion 22 is held by the operator. The handle portion 22 has a grip portion 22A that extends vertically and a connecting portion 22B that extends forward from the upper part of the grip portion 22A. The front end of the connecting portion 22B is connected to the upper part of the rear end of the motor housing portion 21.

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

[0041] The connecting portion 24 is positioned to connect the lower part of the motor housing portion 21 and the front part of the battery holding portion 23.

[0042] The rear of the motor housing 21, the connecting portion 24, the battery holding portion 23, and the handle portion 22 form the loop portion of the main housing 2.

[0043] The motor housing 21 is provided with an air intake port 26 and an exhaust port 27. The air intake port 26 is provided on the left and right sides of the motor housing 21, respectively. The exhaust port 27 is provided at the bottom of the motor housing 21. Air from the external space of the main housing 2 flows into the internal space of the main housing 2 through the air intake port 26. Air from the internal space of the main housing 2 flows out to the external space of the main housing 2 through the exhaust port 27.

[0044] The gear housing 3 houses at least a portion of the power transmission mechanism 8. The gear housing 3 also houses at least a portion of the spindle 9. At least a portion of the gear housing 3 is positioned in front 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 positioned in front of the rear housing 31. At least a portion of the rear housing 31 is positioned inside the front part of the motor housing 21. The front housing 32 is positioned in front of the motor housing 21.

[0046] The rear housing 31 has a plate portion 31A, a recess 31B that is recessed to the rear from the upper part of the plate portion 31A, and a cylindrical portion 31C that protrudes to the rear from the lower part of the plate portion 31A. The front housing 32 has a plate portion 32A and a cylindrical portion 32B that protrudes forward from the plate portion 32A.

[0047] The gear housing 3 is fixed to the front of the motor housing 21. The front of the motor housing 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 positioned to cover at least a portion of the gear housing 3. The cover 4 includes a ring-shaped first cover portion 4A positioned around the front housing 32, a second cover portion 4B positioned at the bottom of the front housing 32, a third cover portion 4C facing the front of the lower part of the plate portion 32A, and a fourth cover portion 4D positioned to cover the lower end of the plate portion 31A and the lower end of the plate portion 32A.

[0049] A battery pack 25 is mounted in the battery mounting section 5. The battery mounting section 5 is located below 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 mounted in 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 an embodiment, the battery pack 25 includes a rechargeable lithium-ion battery. By being mounted in the battery mounting section 5, the battery pack 25 can supply power to the screwdriver 1. The battery pack 25 (battery) powers 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] Motor 6 is the power source for the screwdriver 1. Motor 6 is an electric motor driven by power supplied from the battery pack 25. Motor 6 is an inner-rotor type brushless motor. Motor 6 has a stator 33 and a rotor 34. The stator 33 is supported by the motor housing 21. At least a portion of the rotor 34 is located inside the stator 33. The rotor 34 rotates relative to the stator 33. The rotor 34 rotates around 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 positioned radially outward from the rotor 34 on the rotation axis AX. The stator core 35 includes multiple laminated steel plates. The steel plates are metal plates mainly composed of iron. The stator core 35 is cylindrical. The stator core 35 has multiple teeth that support the coil 37.

[0053] The rear insulator 36R is fixed to the rear of the stator core 35. The front insulator 36F is fixed to the front of the stator core 35. Both the rear insulator 36R and the front insulator 36F are electrically insulating components made of synthetic resin. The rear insulator 36R is positioned to cover a portion of the surface of the teeth of the stator core 35. The front insulator 36F is positioned to cover a portion of the surface of the teeth of the stator core 35.

[0054] The coil 37 is mounted on the stator core 35 via the rear insulator 36R and the front insulator 36F. Multiple 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 isolated by the rear insulator 36R and the front insulator 36F. Multiple coils 37 are interconnected via short-circuiting members 38. Current from the battery pack 25 is supplied to the coils 37 via the controller 20, lead wires (not shown), and a connector 39 fixed to the bottom of the rear insulator 36R. The connector 39 is fixed to the bottom of the rear insulator 36R by screws 39S.

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

[0056] The rotor core 40 and rotor shaft 41 are both 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 positioned radially inward from the rotor core 40. The front part of the rotor shaft 41 protrudes forward from the front end face of the rotor core 40. The rear part of the rotor shaft 41 protrudes rearward from the rear end face of the rotor core 40.

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

[0058] The sleeve 29 is positioned opposite 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 34.

[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 by 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 rotational position of the rotor 34 by detecting the position of the rotor magnet 42. The 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 a rotor bearing 44. The front end of the rotor shaft 41 is rotatably supported by a rotor bearing 45. Both rotor bearings 44 and 45 are ball bearings. The rotor bearing 44 is held in a recess 21A provided at the rear of the inner surface of the motor housing 21. The front end of the inner ring of the rotor bearing 44 contacts a stepped portion provided at the rear of the rotor shaft 41. This prevents the rotor bearing 44 from moving relative to the rotor shaft 41 in the front-rear direction. The rotor bearing 45 is held in a cylindrical portion 31C of the rear housing 31. The rear end of the inner ring of the rotor bearing 45 contacts a stepped portion provided at the front of the rotor shaft 41. A circlip 46 is positioned in front of the rotor bearing 45. The circlip 46 contacts the front end of the inner ring of the rotor bearing 45. This prevents 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 positioned inside the front housing 32 through an opening provided at the front end of the cylindrical portion 31C.

[0061] A pinion gear 47 is fixed to the front end of the rotor shaft 41. The pinion gear 47 rotates around the 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] Fan 7 generates airflow to cool the motor 6. Fan 7 is positioned in front of the stator 33. Fan 7 is positioned between the rotor bearing 45 and the stator 33. Fan 7 is fixed to the rotor shaft 41 between the rotor bearing 45 and the stator 33. Fan 7 rotates with the rotation of the rotor 34. As the rotor shaft 41 rotates, fan 7 rotates together with the rotor shaft 41. The rotation of fan 7 causes air from the external space of the main housing 2 to flow into the internal space of the main housing 2 through the intake port 26. The air that flows into the internal space of the main housing 2 cools the motor 6 by circulating through the internal space of the main housing 2. The air that has circulated through the internal space of the main housing 2 flows out into the external space of the main housing 2 through the exhaust port 27 due to the rotation of 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 this embodiment, the power transmission mechanism 8 includes a clutch mechanism 8A that transmits the rotational force of the motor 6 to the spindle 9 when the motor 6 is rotating 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 is rotating 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, clutch cam 72, and compression spring 75 are located inside the gear housing 3.

[0066] The spindle locking mechanism 8B includes a one-way needle bearing 80 positioned around the spindle 9. The one-way needle bearing 80 is located 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 meshed with the pinion gear 47. The drive gear 71 is a helical gear. The drive gear 71 is positioned 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 positioned around the rotation axis CX. The gear portion 71B is provided on the outer circumference 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 positioned 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 around the rotation axis CX by the drive gear 71. The drive gear 71 is housed in the rear housing 31.

[0068] A one-way needle bearing 80 is positioned 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 positioned in front of the drive gear 71. The clutch cam 72 is positioned 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 positioned around the rotation axis CX. The cylindrical portion 72B is provided to extend rearward from the support ring portion 72A. The cam ring portion 72C is provided to extend radially outward from the rear end of the cylindrical portion 72B. The cam ball groove 72D is provided in the support ring portion 72A. At least some of the balls 73 are positioned 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 this embodiment, three balls 73 are provided. Three cam ball grooves 72D are provided at the front 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 portion of the cam ball grooves 72D is inclined in the front-rear direction. The cam ball grooves 72D are provided so as to surround the rotation axis CX. One ball 73 is arranged in one cam ball groove 72D.

[0071] The spindle 9 has spindle ball grooves 9E. At least a portion of the balls 73 are positioned in the spindle ball grooves 9E. Three spindle ball grooves 9E are provided on the outer circumferential surface of the spindle 9. In a plane perpendicular to the rotation axis CX, each of the three spindle ball grooves 9E is arc-shaped. The spindle ball grooves 9E are arranged to surround the rotation axis CX. One ball 73 is positioned in each spindle ball groove 9E.

[0072] The compression spring 75 is positioned around the spindle 9. The compression spring 75 biases the clutch cam 72 and the spindle 9 forward. The compression spring 75 is positioned inside the cylindrical portion 72B of the clutch cam 72. Washers 76 and balls 77 are positioned around the spindle 9 inside the cylindrical portion 72B of the clutch cam 72. Multiple balls 77 are positioned around the spindle 9. The balls 77 contact the rear surface of the support ring portion 72A. Washers 76 are positioned 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 washers 76 and balls 77. The spindle 9 is coupled to the clutch cam 72 via balls 73. The compression spring 75 biases the clutch cam 72 forward, which in turn biases the spindle 9 forward along with the clutch cam 72.

[0073] The spindle 9 rotates due to the rotational force of the motor 6. At least a portion of the spindle 9 is positioned in front of the power transmission mechanism 8. At least a portion of the spindle 9 is positioned in front of the drive gear 71. The spindle 9 rotates around the 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 due to the rotor 34. The spindle 9 rotates due to 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 the tip tool. The spindle 9 rotates around the rotation axis CX with the driver bit 30 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 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 mounted on the rod portion 9A. The driver bit 30 is inserted into the bit holding hole 9C from the front. 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 makes the spindle 9 lighter. An oil seal 63 is arranged around the rod portion 9A. The oil seal 63 is held in the cylindrical portion 32B of the front housing 32.

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

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

[0077] The front spindle bearing 48 is held in the front housing 32. The front end surface of the outer ring of the front spindle bearing 48 is supported by a protrusion that projects 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 is capable of contacting the rear end surface of the outer ring of the front spindle bearing 48. The spindle 9 is rotatably supported by the front spindle bearing 48 in front of the drive gear 71. The spindle 9 is also supported by the front housing 32 so as to be movable in the longitudinal direction in front of the drive gear 71. The spindle 9 is supported by the gear housing 3 via the front spindle bearing 48 so as to be movable in the longitudinal direction in front of the drive gear 71. The spindle 9 is movable in the longitudinal direction between a forward position and a retracted position behind the forward position. The clutch cam 72 moves in the longitudinal direction together with the spindle 9.

[0078] The driven cam portion 72E of the clutch cam 72 is positioned in front of the drive cam portion 71D of the drive gear 71. The drive cam portion 71D of the drive 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 front spindle bearing 48 so as to be movable in the front-rear direction, such that the drive cam portion 71D and the driven cam portion 72E are in contact with or separated from each other. The driven cam portion 72E moves in the front-rear direction together with the spindle 9 so as to be in contact with or separated from the drive cam portion 71D. When the spindle 9 is in the forward position, the drive cam portion 71D and the driven cam portion 72E are separated. When the spindle 9 is in the retracted position, the drive cam portion 71D and the driven cam portion 72E are in a state where they can contact each other.

[0079] The tool holding mechanism 10 holds the driver bit 30 inserted into the bit holding hole 9C. The tool holding mechanism 10 includes a ball 49 positioned 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 positioned radially outward from the rotation axis CX relative to the ball 49, and a spring 51 positioned outside the ring 50. The ball 49 is pressed radially inward through the ring 50 by the spring 51. At least a portion of the ball 49 is positioned in a recess 30A provided in the driver bit 30, thereby preventing the driver bit 30 from coming out of the bit holding hole 9C.

[0080] The lock ring 11 is operated by the 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 positioned around the cylindrical portion 32B of the front housing 32. The lock ring 11 can rotate relative to the front housing 32. By rotating, the lock ring 11 moves in the front-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 adjustment sleeve 12 is detachably attached to the lock ring 11. The adjustment sleeve 12 is attached to the lock ring 11 via an O-ring 52. The adjustment sleeve 12 is positioned around the spindle 9 in front of the lock ring 11. The adjustment sleeve 12 is substantially cylindrical. The adjustment sleeve 12 is tapered, decreasing in diameter towards the front. The adjustment 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 adjustment sleeve 12. The rubber cap 13 is fixed to the front end of the adjustment sleeve 12. The rubber cap 13 is positioned around the driver bit 30 attached to the spindle 9. During screw tightening operations using the screwdriver 1, the rubber cap 13 comes into contact with the workpiece. The rubber cap 13 helps to prevent damage to the workpiece.

[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 in front of the front end of the rubber cap 13. To adjust the screw tightening depth to the workpiece, the operator rotates the lock ring 11 to move it in the forward and backward directions. As the lock ring 11 moves in the forward and backward directions, the adjustment sleeve 12 and the rubber cap 13 move together with the lock ring 11. This adjusts the amount the driver bit 30 protrudes from the front end surface of the rubber cap 13. By adjusting the amount the driver bit 30 protrudes from the front end surface of the rubber cap 13, the screw tightening depth to the workpiece is adjusted.

[0084] The trigger lever 14 is operated by the operator to start the motor 6. The trigger lever 14 is located on the grip portion 22A. The trigger lever 14 protrudes forward from the upper front part of the grip portion 22A. A switch 54 is located 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 backward, 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 stops.

[0085] The lock button 15 is operated by the operator to maintain the pulled-back position of the trigger lever 14. The lock button 15 is located on the upper left side of the grip portion 22A. When the lock button 15 is pressed while the trigger lever 14 is pulled back, the trigger lever 14 remains pulled back even when the operator releases the trigger lever 14, and the motor 6 continues to operate.

[0086] The forward / reverse rotation selector lever 16 is operated by the operator to switch the rotation direction of the motor 6. The forward / reverse rotation selector lever 16 is located on the connecting portion 22B. When the forward / reverse rotation selector lever 16 is operated, the rotation direction of the motor 6 is switched from one direction to the other. Switching the rotation direction of the motor 6 switches the rotation direction of the spindle 9. When the forward / reverse rotation selector lever 16 is in the neutral position, the trigger lever 14 cannot be operated.

[0087] Light 17 emits illumination light. Light 17 includes a light-emitting diode (LED). Light 17 is positioned at the front of the lower part of the coupling section 24. Light 17 illuminates the front of the spindle 9 with illumination light.

[0088] The switch plate 18 has a mode switching button 18A that is operated by the 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 operating mode of the motor 6 is switched by the operator operating the mode switching button 18A. In this embodiment, the operating modes of the motor 6 include a normal mode and a push-drive mode. The normal mode is an operating mode in which the motor 6 is started by pulling the trigger lever 14. The push-drive mode is an operating mode in which the motor 6 does not start immediately even when the trigger lever 14 is pulled, but the motor 6 is started after it is detected that the spindle 9 has moved from the forward position to the rear position together with the driver bit 30. The operator can set either the normal mode or the push-drive mode (also called Auto Start) of the screwdriver 1 to operating mode by operating the mode switching button 18A.

[0089] The bit position detection unit 19 operates to detect when the motor 6's operating mode is set to push drive mode, and when the spindle 9 moves backward from the forward position together with the driver bit 30.

[0090] The bit position detection unit 19 includes a bearing 90, a movable member 91, a magnet 92, and a mode sensor substrate 93.

[0091] The bearing 90 is positioned around the cylindrical portion 72B of the clutch cam 72. The bearing 90 rotatably supports the clutch cam 72.

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

[0093] As described above, the spindle 9 is movable in the front-rear direction between a forward position and a retracted position. The clutch cam 72 moves in the front-rear direction together with the spindle 9. The movable 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 movable member 91 move together in the front-rear direction relative to the front housing 32. The clutch cam 72 is a push-button clutch located in front of the motor 6 and driven by the motor 6. The spindle 9 is located in front of the clutch cam 72, which is a push-button clutch, and is driven by the clutch cam 72. As shown in Figure 5, a receiving recess 31D is provided at the rear of the recess 31B of the rear housing 31, which accommodates the rear end of the spindle 9 when it has moved to the retracted position.

[0094] The movable member 91 has a ring portion 91A positioned around the bearing 90 and a protrusion 91B projecting downward from the ring portion 91A. As shown in Figure 8, a recess 32G is provided on the inner circumferential surface of the front housing 32. The protrusion 91B is positioned in the recess 32G. The position of the protrusion 91B in the recess 32G suppresses relative rotation between the movable member 91 and the front housing 32. In other words, the movable member 91 is prevented from rotating by the protrusion 91B and the recess 32G. The protrusion 91B and the recess 32G function as an anti-rotation mechanism that suppresses the rotation of the movable member 91 relative to the front housing 32. The clutch cam 72 is rotatably supported on the movable member 91 via the bearing 90. The clutch cam 72 and the spindle 9 are rotatable relative to the movable member 91 and the front housing 32. The recess 32G is provided so as to extend in the front-rear direction. The protrusion 91B is movable in the front-rear direction inside the recess 32G. The recess 32G functions as a guide portion that guides the movable member 91 in the front-rear direction.

[0095] The magnet 92 is positioned in front of the spindle rear bearing 62. The magnet 92 is positioned in front of the drive gear 71. The magnet 92 moves in the forward and backward directions in synchronization with the spindle 9. In one embodiment, the magnet 92 is fixed to a protrusion 91B of the moving member 91. The magnet 92 may be embedded inside the moving member 91. In the forward and backward directions, the position of the magnet 92 is equal to the position of at least a portion of the spindle 9. The magnet 92 moves in the forward and backward directions 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 a magnet 92. The mode sensor board 93, including the magnetic sensor 94, is positioned radially outward from the rotation axis CX. The mode sensor board 93 is positioned forward of the spindle rear bearing 62. The mode sensor board 93 is positioned forward of the drive gear 71. In the front-rear direction, the position of the mode sensor board 93 is equal to the position of at least a portion of the spindle 9. At least a portion 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. Because the mode sensor board 93 is positioned outside (below) the front housing 32, grease applied to the spindle 9, drive gear 71, clutch cam 72, etc., is prevented from adhering to the mode sensor board 93. In addition, heat generated in the spindle 9, drive gear 71, clutch cam 72, etc., is prevented from being transmitted to the mode sensor board 93. Therefore, deterioration or damage to the mode sensor board 93, including the magnetic sensor 94, is suppressed. The mode sensor board 93 may also be supported by the front housing 32.

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

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

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

[0100] The controller 20 controls the motor 6 based on the detection signal from the magnetic sensor 94. In normal mode, the controller 20 starts the motor 6 when it receives an operation signal indicating that the trigger lever 14 has been pulled. In push-drive mode, the controller 20 starts the motor 6 when it receives an operation signal indicating that the trigger lever 14 has been pulled, and also receives a detection signal from the magnetic sensor 94 indicating 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 be opposite to the drive cam portion 71D. The clutch cam 72 is positioned 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 screw tightening operations on a workpiece, the forward / reverse rotation switch lever 16 is operated so that the rotor 34 of the motor 6 rotates in the forward direction. After the driver bit 30 is inserted into the bit holding hole 9C and the driver bit 30 is mounted on the rod portion 9A, the operator grips the handle portion 22 and inserts the tip of the driver bit 30 into the cross groove of the screw head 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 normal mode is described below. In normal mode, the motor 6 is started when the trigger lever 14 is pulled. When the motor 6 is started and the rotor 34 rotates forward, 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 forward, the drive gear 71 and the spindle 9 rotate relative to each other due to the action of the one-way needle bearing 80 located between the drive gear 71 and the spindle 9. In other words, when the rotor 34 rotates forward, 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 is rotating in the forward position and the spindle 9 is in the forward position, even if the drive gear 71 rotates, the drive cam portion 71D and the driven cam portion 72E are separated, so rotational force is not transmitted from the drive gear 71 to the clutch cam 72.

[0105] With the drive gear 71 rotating, the operator grips the handle 22 and performs a pushing motion to bring the screwdriver 1 closer to the workpiece. Due to the pushing motion of the screwdriver 1, the spindle 9, along with the driver bit 30, moves backward against the elastic force of the compression spring 75.

[0106] When the spindle 9 moves to the retracted position, the drive cam portion 71D and the driven cam portion 72E come into contact. When the spindle 9 moves from the forward position to the retracted position and the drive cam portion 71D and the driven cam portion 72E come into contact, the clutch cam 72 receives a rotational resistance force from the spindle 9, and as a result, the ball 73 rolls between the spindle ball groove 9E and the cam ball groove 72D, causing the spindle 9 and the clutch cam 72 to rotate relative to each other via the ball 73. As 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, the spindle 9 and the clutch cam 72 can rotate together. In this embodiment, at least a portion of the cam ball groove 72D is inclined in the front-rear direction, so when the drive cam portion 71D and the driven cam portion 72E come into contact, the spindle 9 and the clutch cam 72 rotate relative to each other via the ball 73, causing the clutch cam 72 to move backward.

[0107] As the spindle 9 and clutch cam 72 move backward and the drive cam portion 71D and driven cam portion 72E come into contact, the motor 6 is driven, causing the spindle 9 and clutch cam 72 to 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, which includes the drive cam portion 71D and the driven cam portion 72E. As the driver bit 30 rotates forward together with the spindle 9, the screw is driven into the workpiece.

[0108] During the screw tightening operation, the operator continues the pushing motion of 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. In the initial stages of the screw tightening operation, the torque applied from the screw to the spindle 9 via the driver bit 30 is large, but towards the end of the screw tightening operation, the torque applied from the screw to the spindle 9 via the driver bit 30 decreases. As 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. As 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 drive cam section 71D and the driven cam section 72E separate, and the rotation of the spindle 9 stops. With this, the screw tightening operation is completed.

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

[0110] <Push Drive Mode> Next, the operation of the screwdriver 1 in push-drive mode will be described. In push-drive mode, the motor 6 does not start simply by pulling the trigger lever 14. When the spindle 9 moves backward due to the pushing operation of 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 on the mode sensor board 93. When the motor 6 starts, the rotation of the drive gear 71 begins. As the pushing operation continues, the spindle 9 moves toward the retracted position. When the spindle 9 moves toward the retracted position and the drive cam portion 71D and the driven cam portion 72E come into contact, the spindle 9 rotates due to the rotational force of the drive gear 71 transmitted via the clutch mechanism 8A, which includes the drive cam portion 71D and the driven cam portion 72E. As the driver bit 30 rotates forward along with the spindle 9, the screw is driven into the workpiece.

[0111] As the screw tightening process progresses, the screwdriver 1 gradually approaches the workpiece, until the front end of the rubber cap 13 comes into contact with it. As 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 separates the drive cam portion 71D and the driven cam portion 72E, stopping the rotation of the spindle 9. With this, the screw tightening process is completed.

[0112] When the screw tightening operation is completed, the pushing action is released, and the driver bit 30 separates from the screw, the spindle 9 returns to the forward position due to the biasing force of the compression spring 75. As the spindle 9 returns to the forward position, the moving member 91 and the magnet 92 also return to the forward position. The controller 20 stops the motor 6 based on the change in the magnetic field detected by the magnetic sensor 94 on 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 is reversed. The spindle lock mechanism 8B includes a one-way needle bearing 80 positioned around the spindle 9. When the rotor 34 is reversed, 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, preventing relative rotation between the drive gear 71 and the spindle 9. When the rotor 34 is reversed, the drive gear 71 and the spindle 9 rotate together without relative rotation. When the rotor 34 is reversed, the drive gear 71 and the spindle 9 rotate together, so even if the drive cam portion 71D and the driven cam portion 72E are separated, the rotation of the drive gear 71 is transmitted to the spindle 9. When performing a screw removal operation to remove screws from a workpiece, the motor 6 is reversed. In the screw removal operation, the spindle 9 can rotate even if it does not move from the forward position to the retracted position. In other words, the spindle 9 rotates even if a pushing motion is not performed to push the screwdriver 1 closer to the workpiece.

[0114] [effect] As described above, in this embodiment, the screwdriver 1 comprises a gear housing 3, a motor 6, a pinion gear 47 rotated by the motor 6, a drive gear 71 that meshes with the pinion gear 47 and rotates around the first rotation axis, which is the rotation axis CX, a spindle 9 supported in the gear housing 3 so as to be movable in the front-rear direction in front of the drive gear 71 and rotatable around the rotation axis CX with the tip tool, which is the screwdriver bit 30, attached, a drive cam portion 71D that rotates around the rotation axis CX by the drive gear 71, and a part positioned in front of the drive cam portion 71D that contacts the drive cam portion 71D or the drive cam portion 7 The motor 6 comprises a driven cam section 72E that moves in the front-rear direction together with the spindle 9 so as to move away from 1D, a spindle 9 which is a support shaft that rotates around the rotation axis CX while supporting the drive gear 71, a spindle rear bearing 62 which is a first bearing that is positioned behind the drive gear 71 and rotatably supports the spindle 9, a magnet 92 which is positioned in front of the spindle rear bearing 62 and moves in the front-rear direction in synchronization with the spindle 9, a magnetic sensor 94 which is positioned 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 magnetic sensor 94 are positioned in front of the spindle rear bearing 62, thus preventing the overall length of the screwdriver 1 from increasing. 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. Alternatively, the overall length of the screwdriver 1 may 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 positioned in front of the drive gear 71.

[0117] In the above configuration, the magnet 92 and magnetic sensor 94 are positioned in front of the drive gear 71, which prevents the overall length of the screwdriver 1 from increasing.

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

[0119] In the above configuration, the position of the magnet 92 and the position of at least a portion of the spindle 9 are equal in the front-to-back direction, so the overall length of the screwdriver 1 is suppressed.

[0120] In one embodiment, the screwdriver 1 includes a movable member 91 positioned around the spindle 9 and moving together with the spindle 9 in the front-rear direction. The magnet 92 is fixed to the movable member 91.

[0121] In the above configuration, the magnet 92 moves in the front-to-back direction together with the spindle 9.

[0122] In this embodiment, the screwdriver 1 includes a bearing 90 which is a second bearing disposed between the spindle 9 and the movable member 91, and an anti-rotation mechanism including a protrusion 91B and a recess 32G that suppress the rotation of the movable member 91 relative to the gear housing 3.

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

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

[0125] In the above configuration, the spindle 9, clutch cam 72, bearing 90, and the movable member 91 to which the magnet 92 is fixed are moved together in the front-rear direction, thus suppressing structural complexity.

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

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

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

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

[0130] In one embodiment, the screwdriver 1 comprises a motor 6, a clutch cam 72 which is a push-button clutch located in front of the motor 6 and driven by the motor 6, a spindle 9 located in front of the clutch cam 72 and driven by the clutch cam 72, a magnetic sensor 74 which is a push-button sensor located radially outward of 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 positioned radially outward of the clutch cam 72, which is a push-in clutch, thus suppressing an increase in the overall length of the screwdriver 1.

[0132] The magnetic sensor 94 may be directly or indirectly fixed to the clutch cam 72. If the magnetic sensor 94 is indirectly fixed to the clutch cam 72, it will be fixed via one or more other members. In any case, the magnetic sensor 94 only needs to be positioned radially outward from the clutch cam 72. The magnetic sensor 94 is positioned between the front and rear ends of the clutch cam 72.

[0133] [Other embodiments] Figure 12 is a longitudinal cross-sectional view showing the main parts of a modified screwdriver. As shown in Figure 12, the mode sensor substrate 93, including the magnetic sensor 94, may be positioned in front of the spindle front bearing 48. Also, the magnet 92A may be positioned in front of the spindle front bearing 48.

[0134] Figure 13 is a longitudinal cross-sectional view showing the main parts of a modified screwdriver. In the above-described embodiment, the spindle 9 includes a support shaft. As shown in Figure 13, the drive gear 710 may be supported by a support shaft 730 different from the spindle 900. At least a portion of the spindle 900 is positioned in front of the support shaft 730. A clutch cam 720 may also 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 substrate 93, including the magnetic sensor 94, is positioned in front of the bearing 620. The mode sensor substrate 93, including the magnetic sensor 94, may also be positioned in front of the drive gear 710. In the example shown in Figure 13, the mode sensor substrate 93, including the magnetic sensor 94, is positioned radially outward from the support shaft 730. The magnet 92B is positioned 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 is equal to the position of at least a portion of the support shaft 730. Also, in the front-rear direction, the position of the magnet 92B may be equal to the position of at least a portion of the support shaft 730.

[0135] In the above embodiment, the spindle 9 and the magnet 92 move together in the front-rear direction. For example, the movement of the magnet 92 may begin after the movement of the spindle 9 begins. Also, the distance traveled by the spindle 9 and the distance traveled by the magnet 92 may be equal or different. Furthermore, when the spindle 9 moves backward, the magnet 92 may move forward. The magnet 92 should move in sync with the spindle 9.

[0136] In the above embodiment, the push sensor for detecting when the clutch cam 72, which is a push-button clutch, is pushed in is a magnetic sensor 94 (Hall element) that detects magnets (such as 92). The push sensor is not limited to the magnetic sensor 94 and only needs to be able to detect when the clutch cam 72 is pushed in. Any non-contact sensor can be used as the push sensor. The push sensor may also be a contact switch. For example, the clutch cam 72 may be detected as being pushed in when a switch such as a tact switch is pressed against the clutch cam 72.

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

[0138] 1...Screwdriver, 2...Main housing, 2A...Recess, 2L...Left housing, 2R...Right housing, 2S...Screw, 3...Gear housing, 3S...Screw, 4...Cover, 4A...First cover section, 4B...Second cover section, 4C...Third cover section, 4D...Fourth cover section, 5...Battery mounting section, 6...Motor, 7...Fan, 8...Power transmission mechanism, 8A...Clutch mechanism, 8B...Spindle lock mechanism, 9...Spindle, 9A...Rod section, 9B...Stopper section, 9C...Bit holding hole, 9D...Hollow hole, 9E...Spindle ball groove, 9F...Through hole, 10...Tool holding mechanism, 11...Ro 12...Catching, 13...Adjustable sleeve, 14...Rubber cap, 15...Trigger lever, 16...Lock button, 17...Forward / reverse rotation lever, 18...Light, 18...Switch plate, 18A...Mode switching button, 19...Bit position detection unit, 20...Controller, 20A...Circuit board, 20B...Case, 21...Motor housing, 21A...Recess, 22...Handle unit, 22A...Grip unit, 22B...Connecting unit, 23...Battery holder, 24...Connecting unit, 25...Battery pack, 26...Air intake, 27...Exhaust port, 29...Sleeve, 30...Driver bit, 30A...Recess, 31...Rear Side housing, 31A...plate section, 31B...recess, 31C...cylindrical section, 31D...housing recess, 32...front housing, 32A...plate section, 32B...cylindrical section, 32G...recess, 33...stator, 34...rotor, 35...stator core, 36F...front insulator, 36R...rear insulator, 37...coil, 38...short-circuiting component, 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 section, 71B...Gear section, 71C...Cylindrical section, 71D...Drive cam section, 72...Clutch cam, 72A...Support ring section, 72B...Cylindrical section, 72C...Cam ring section, 72D...Cam ball groove, 72E...Driven cam section, 73...Ball, 75...Compression spring, 76...Washer, 77...Ball, 80...One-way needle bearing90...Bearing (2nd bearing), 91...Moving member, 91A...Ring part, 91B...Protrusion, 92...Magnet, 92A...Magnet, 92B...Magnet, 93...Mode sensor substrate, 94...Magnetic sensor, 95...Resin layer, 96...Lead wire, 480...Spindle bearing, 620...Bearing, 710...Drive gear, 720...Clutch cam, 730...Support shaft, 750...Compression spring, 900...Spindle, AX...Rotating shaft, CX...Rotating shaft (1st rotating shaft).

Claims

1. Housing and Motor and, A pinion gear rotated by the aforementioned motor, A drive gear that rotates around the first rotation axis while meshed with the aforementioned pinion gear, A spindle is supported in the housing so as to be movable in the front-rear direction in front of the drive gear, and is rotatable about the first rotation axis with the tip tool attached, The drive gear provides a drive cam section that rotates around the first rotation axis, A driven cam portion is positioned in front of the drive cam portion, biased by a spring to contact or separate from the drive cam portion, and moves in the front-rear direction together with the spindle, With the drive gear supported, a support shaft rotates around the first rotation axis, A first bearing is positioned behind the drive gear and rotatably supports the support shaft, A magnet positioned in front of the first bearing and moving in the forward and backward directions in synchronization with the spindle, A magnetic sensor is positioned radially outward from the first rotation axis to detect the magnet, The system includes a controller that controls the motor based on the detection signal from the magnetic sensor, The system further comprises a movable member positioned around the spindle and the spring, which moves together with the spindle in the front-rear direction, The magnet is fixed to the moving member, The magnetic sensor is positioned radially outward from the magnet and facing the magnet in the radial direction. Screwdriver.

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

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

4. A second bearing is disposed between the spindle and the moving member, The system includes an anti-rotation mechanism that suppresses the rotation of the moving member relative to the housing, The screwdriver according to claim 1.

5. The clutch cam is arranged around the spindle, coupled to the spindle via a ball, and is provided with the driven cam portion. The moving member is arranged around the clutch cam, The second bearing is positioned between the clutch cam and the moving member. The screwdriver according to claim 4.

6. The moving member is provided with a guide portion that guides it in the front-rear direction. The screwdriver according to claim 1.

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

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

9. Motor and, A push-button clutch is positioned in front of the motor, biased forward by a spring, and driven by the motor, A spindle positioned in front of the aforementioned push clutch and driven by the push clutch, A push sensor is positioned radially outward of the push clutch to detect when the push clutch is pushed in, The motor is powered by a battery, The spring and the push-clutch are further equipped with a movable member that is rotatably positioned relative to the outer circumference and has a magnet attached to it. The aforementioned push sensor is a magnetic sensor that faces the magnet from the radially outer side. Screwdriver.

Images