Power Tools

Abstract

The present invention provides an electric tool. A rechargeable angle screwdriver (1) comprises a stator (21), a rotor (22) and terminal fittings (34A, 34B, etc.), wherein the stator (21) comprises: a cylindrical stator core (23); a front insulator (24) and a rear insulator (25) fixed to the stator core (23); a coil (26) wound around the stator core (23) via the front insulator (24) and the rear insulator (25); and a welding terminal (32), which is connected to the coil (26), the rotor (22) can rotate relative to the stator (21), the terminal fittings (34A, 34B...) are integrally provided with the terminal unit (33), and are connected to the welding terminal (32), and are connected to the power line (83), and when viewed from the axial direction of the stator core (23), the terminal fittings (34A, 34B...) are arranged at a position closer to the inside than the outer diameter of the stator core (23). According to the present invention, the housing for housing the stator can be made compact.

Description

Technical Field

[0001] The present invention relates to an electric tool, and more particularly to an invention suitable for an angle screwdriver. Background Art

[0002] For example, in an electric tool such as an angle screwdriver, the stator of a motor housed in a housing and a controller are electrically connected via a wire (power cord). As a connection method, Patent Document 1 discloses an invention in which each welding terminal of a wire welded to a coil is clamped to a connecting piece protruding radially from an insulator, and a terminal unit is assembled and screwed onto the connecting piece, wherein the terminal unit is soldered and brazed with wires corresponding to each welding terminal from the controller wiring. By using this terminal unit, the stator and the controller can be separated, thereby achieving improved assembly and repairability.

[0003] [Prior art literature]

[0004] [Patent Literature]

[0005] Patent Document 1: Japanese Patent Publication No. 2018-137843 Summary of the invention

[0006] [Technical problem to be solved by the invention]

[0007] However, in the electric tool of Patent Document 1, since the terminal unit is assembled in a form exposed radially outward from the stator and the wire is pulled radially outward, it is necessary to make the exposed portion of the terminal unit partially protrude in the shell that houses the stator, or to increase the diameter of the shell, thereby hindering compactness.

[0008] On the other hand, since the lead wires are assembled using the terminal unit, it takes time and effort to assemble them.

[0009] Therefore, an object of the present invention is to provide an electric tool in which a housing accommodating a stator can be made compact.

[0010] [Technical solutions for solving technical problems]

[0011] In order to achieve the above-mentioned purpose, the invention recorded in technical solution 1 is: an electric tool, characterized in that it has a stator, a rotor and a lead terminal, wherein the stator has: a cylindrical stator core (Stator Core); an insulator, which is fixed to the stator core; a coil, which is wound around the stator core through the insulator; and a coil terminal, which is connected to the coil, the rotor is rotatable relative to the stator, the lead terminal is integrally provided with the resin component, and is connected to the coil terminal, and is connected to a lead, and the invention is characterized in that, viewed from the axial direction of the stator core, the lead terminal is arranged at a position closer to the inside than the outer diameter of the stator core.

[0012] Technical solution 2 of the present invention is based on the structure of technical solution 1, and is characterized in that the lead terminal is connected to the coil terminal by a screw.

[0013] Technical solution 3 of the present invention is based on the structure of technical solution 1 or 2, and is characterized in that the coil terminal is retained by an insulator, and the connection portion of the coil terminal with the lead terminal extends along the axial direction of the stator, and, when viewed from the axial direction of the stator core, the coil terminal is arranged at a position closer to the inside than the outer diameter of the stator core.

[0014] Technical solution 4 of the present invention is based on the structure of technical solution 3, and is characterized in that the coil terminal and the lead terminal are overlapped in the radial direction of the stator and fixed by screws.

[0015] A fifth aspect of the present invention is the structure according to any one of the first to fourth aspects, wherein the resin member is formed in a ring shape.

[0016] In order to achieve the above-mentioned purpose, the invention recorded in technical solution 6 is: an electric tool, characterized in that it has a stator, a rotor, a power cord, a sensor circuit substrate, and a signal line, wherein the stator has: a cylindrical stator core; an insulator, which is fixed to the stator core; a coil, which is wound around the stator core through the insulator; and a coil terminal, which is connected to the coil, the rotor can rotate relative to the stator, and the power cord is directly or indirectly connected to the coil terminal; the sensor circuit substrate is fixed to the insulator; the signal line is connected to the sensor circuit substrate, and the power cord and the signal line are pulled out in the same direction in the axial direction of the stator.

[0017] [Effects of the invention]

[0018] According to the present invention, the housing for housing the stator can be made compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a central longitudinal section view of a cordless angle screwdriver.

[0020] Figure 2This is an enlarged view of a brushless motor.

[0021] Figure 3 It is a three-dimensional diagram of the stator.

[0022] Figure 4 This is a three-dimensional exploded view of the stator.

[0023] Figure 5 This is an exploded perspective view of the stator with the sensor circuit board assembled.

[0024] Figure 6 It is a longitudinal cross-sectional view of the stator.

[0025] Figure 7 It is a perspective view of a stator according to a modified example.

[0026] [Description of Reference Numerals]

[0027] 1: Rechargeable angle screwdriver; 2: Main body; 3: Motor housing; 4: Brushless motor; 5: Clutch housing; 6: Clutch; 7: Handle housing; 8: Battery mounting portion; 10: Front housing; 11: Output portion; 12: Output shaft; 13: Battery pack pack); 15: controller; 16: control circuit board; 21: stator; 22: rotor; 26: coil; 27: rotating shaft; 31: sensor circuit board; 32: welding terminal; 33: terminal unit; 34A~34C: terminal accessories; 40: circular plate portion; 41: fixing plate; 45: screw protrusion; 47: signal line connection portion; 48: signal line; 50: folding plate; 51: connecting plate; 60A, 60B: straight portion; 61: notch; 62: nut seat; 63: nut; 67: loading plate; 75: insertion portion; 77: caulking fastening portion; 81, 82: screws; 83: power cord; 98: spindle. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0029] Figure 1 It is a central longitudinal sectional view of a rechargeable angle screwdriver (hereinafter simply referred to as a “screwdriver”) 1 which is an example of an electric tool.

[0030] (Description of the overall structure)

[0031] The main body 2 of the screwdriver 1 is a cylindrical body extending linearly in the front-rear direction, and comprises: a motor housing 3, which houses a brushless motor 4 in the center in the front-rear direction; a clutch housing 5, which is connected to the front side of the motor housing 3, houses a clutch 6 and extends forward; a grip housing 7, which is connected to the rear side of the motor housing 3 and extends rearward; and a battery mounting portion 8, which is connected to the rear side of the grip housing 7. The main body 2 is formed by assembling left and right split housings 2a and 2b by screws 9, 9...

[0032] A front housing 10 having an inverted L-shape in a side view is connected to the front end of the main body 2 , and the front housing 10 accommodates the output unit 11 and extends forward so that the output shaft 12 protrudes downward.

[0033] On the other hand, a battery pack 13 serving as a power source is mounted on the battery mounting portion 8 in a manner that allows sliding from below, and a terminal block 14 electrically connected to the mounted battery pack 13 is provided in the battery mounting portion 8. On the front side of the terminal block 14, a controller 15 is provided in parallel with the terminal block 14, and the controller 15 is composed of a control circuit board 16 equipped with a capacitor, a microcomputer, a switching element, etc., housed in a box body 17.

[0034] In front of the terminal block 14, a trigger switch 18 with a trigger 19 protruding downward is housed in the front part of the handle housing 7. In front of the trigger switch 18, a forward / reverse switching button 20 for the brushless motor 4 is provided.

[0035] (Description of brushless motor)

[0036] The brushless motor 4 is an inner rotor type motor having a cylindrical stator 21 and a rotor 22 penetrating the stator 21. Figure 2 As shown, the stator 21 includes: a stator core 23; a front insulator 24 and a rear insulator 25, which are arranged in front and rear of the stator core 23; and a plurality of coils 26, 26..., which are wound around the stator core 23 via the front insulator 24 and the rear insulator 25 to form a three-phase winding. The rotor 22 includes: a rotating shaft 27, which is located at the axis; a cylindrical rotor core 28, which is arranged around the rotating shaft 27; permanent magnets 29, 29..., which are arranged outside the rotor core 28 and make the magnetism alternate in the circumferential direction; and a plurality of permanent magnets 30, 30..., which are arranged radially on the rear side of the permanent magnets 29, 29...

[0037] In addition, Figure 3As shown, in the stator 21, a sensor circuit substrate 31 is mounted at the rear end of the rear insulator 25, on which a rotation detection element (not shown) is mounted for detecting the position of the sensor permanent magnet 30 and outputting a rotation detection signal; three welding terminals 32, 32 ... as coil terminals, which are welded to the magnet wires 26a of each phase of the coil 26; and a terminal unit 33 having three terminal fittings 34A to 34C as lead wire terminals, wherein the three terminal fittings 34A to 34C are used to connect the power lines (lead wires) of the three phases to the welding terminals 32. The following will be described in order.

[0038] Another example Figure 4 , 5 As shown, on the sensor circuit substrate 31, three fixing pieces 41, 41 ... having through holes 42 at the top are radially protruded and arranged at approximately equal intervals in the radial direction of the stator 21 on a disc portion 40 having a diameter smaller than the inner diameter of the stator core 23, and a pair of positioning pieces 43A, 43B having through holes 44A, 44B at the top are arranged on the radial left and radial right sides of the fixing piece 41 on the lower side. Among them, the fixing piece 41 corresponds to three screw protrusions 45, 45 ... protruding backward from the rear insulator 25, and the positioning pieces 43A, 43B correspond to two positioning pins 46A, 46B protruding backward from the rear insulator 25 and having different outer diameters. Therefore, the through holes 44A, 44B of the positioning pieces 43A, 43B are also different in size. A signal line connection portion 47 is arranged on the rear surface of the disc portion 40, and the signal line connection portion 47 is connected to the signal line 48 outputting the detection signal of the rotation detection element backward.

[0039] The welding terminal 32 is formed by bending a strip-shaped metal plate to form a folded piece 50 at the front end thereof and a connecting piece 51 having a through hole 52 at the rear end thereof. A pair of protruding pieces 53, 53 are formed between the folded piece 50 and the connecting piece 51. A pair of retaining portions 54, 54 are provided on the rear surface of the rear insulator 25 to protrude rearward between the screw protrusions 45, 45, and the pair of retaining portions 54, 54 retain the protruding pieces 53, 53 of the welding terminal 32.

[0040] Therefore, each welding terminal 32 is assembled to the rear insulator 25 by inserting the protruding pieces 53, 53 into the retaining parts 54, 54 in a posture in which the folded-back pieces 50 face the radially outer side of the stator 21. In this state, the connection piece 51 protrudes rearward in the axial direction of the stator 21. And, the magnetic wire 26a is sandwiched and welded by the folded-back pieces 50, so that the welding terminal 32 is electrically connected to the magnetic wire 26a. Through the welding terminal 32, the two coils 26 form a delta connection scheme in series.

[0041] When viewed from the rear of the stator 21 in the axial direction, the terminal unit 33 is in the shape of a resin ring that is accommodated inside the outer diameter of the stator 21. However, when viewed from the rear, the terminal unit 33 is in the shape of a hexagon that has three straight portions 60A, 60A, ... corresponding to the respective holding portions 54, 54 of the rear insulator 25 and three straight portions 60B, 60B, ... corresponding to the respective screw protrusions 45. A notch 61 is formed on the outer surface of each straight portion 60A, into which the connecting piece 51 of the welding terminal 32 fits from the front, and a nut seat 62 is formed on the inner surface of each straight portion 60A, which is open on the rear surface and radially inside to hold the nut 63. A partition wall 64 is provided between the notch 61 and the nut seat 62, and a communication hole 65 is formed on the partition wall 64 to communicate the notch 61 and the nut seat 62. On the outer side of the partition wall 64, a groove 66 is formed parallel to the partition wall 64, which is open on the rear surface of the terminal unit 33 and communicates with the notch 61.

[0042] In addition, at the front end of the outer surface of each straight portion 60B, a mounting piece 67 is formed extending radially outward, and the mounting piece 67 is aligned with the position of the screw protrusion 45 and has a through hole 68. The back side of each mounting piece 67 is formed with an engaging portion 69 that engages with the corner of the fixing piece 41 of the sensor circuit substrate 31. A circular arc-shaped escape portion 70 is formed on each straight portion 60B, and the escape portion 70 is used to prevent interference with the screw 82 inserted into the through hole 68.

[0043] The terminal fittings 34A to 34C are mounted on the rear surface of the terminal unit 33. The terminal fittings 34A to 34C include: an insertion portion 75 facing forward, which has a through hole 76 and is inserted into the groove 66 of the straight portion 60A; a caulking fastening portion 77 that stands up toward the rear; and an intermediate portion 78 that connects the insertion portion 75 and the caulking fastening portion 77. After the insertion portion 75 is inserted into the groove 66 located radially outside the signal line connection portion 47 of the sensor circuit substrate 31 and the intermediate portion 78 is arranged on the inner side on the rear surface of the straight portion 60A, the terminal fitting 34A becomes a short fitting in which the caulking fastening portion 77 stands up from the rear of the nut seat 62. After the insertion portion 75 is inserted into the groove 66 of the remaining two straight portions 60A, 60A respectively and the intermediate portion 78 extends along the rear surface of the terminal unit 33 to the vicinity of the terminal fitting 34A, the other two terminal fittings 34B, 34C become long fittings with the caulking fastening portions 77, 77 standing on the left and right sides of the caulking fastening portion 77 of the terminal fitting 34A. Accordingly, the three caulking fastening portions 77, 77 ... of the terminal fittings 34A to 34C are arranged on a straight line in the left-right direction along the straight portion 60A. A pair of locking pieces 79, 79 are punched out on the intermediate portion 78 of the terminal fittings 34B, 34C, and the top ends of the pair of locking pieces 79, 79 face each other, and a fitting protrusion 80 is protrudingly provided on the rear surface of the terminal unit 33, and the fitting protrusion 80 is fitted in the middle of the locking pieces 79, 79 of the terminal fittings 34B, 34C to position the intermediate portion 78.

[0044] Here, if Figure 5 As shown, when the sensor circuit substrate 31 and the terminal unit 33 are assembled to the stator 21, with the magnetic wire 26a welded to the welding terminal 32 held in each holding portion 54, 54, the sensor circuit substrate 31 and the signal line connection portion 47 are located on the upper side (the rear insulator 25 is described as the upper side during assembly), the through holes 44A, 44B of each positioning piece 43A, 43B are embedded in the positioning pins 46A, 46B of corresponding size, and each fixing piece 41 is assembled on the upper side of each screw protrusion 45.

[0045] Next, in the terminal unit 33, while the nuts 63 are respectively held on the nut seats 62, the terminal fittings 34A to 34C are assembled on the upper surface of the terminal unit 33 and the insertion portions 75 are inserted into the grooves 66 for positioning. The connecting pieces 51 of each welding terminal 32 are fitted into each notch 61, and each carrier piece 67 is placed on each fixing piece 41, so that the terminal unit 33 is positioned by the snap-fit ​​portion 69. In this state, the screw 81 is passed through each notch 61 from the radial outside in the order of the through hole 52 of the connecting piece 51, the connecting hole 65 of the partition wall 64, and the through hole 76 of the insertion portion 75 to be screwed into the nut 63 on the inside, and the screw 82 is screwed into the screw protrusion 45 from above through the through hole 68 of each carrier piece 67 and the through hole 42 of each fixing piece 41. Thus, as shown in FIG. Figure 6 As shown, the sensor circuit substrate 31 is fixed to the rear insulator 25 by screws 82, and the terminal fittings 34A to 34C of the terminal unit 33 are also fixed to the respective welding terminals 32 by screws 81, and by engaging the heads of the screws 82 with the through holes 68 of the mounting sheet 67, the stator 21 is fixed on the upper side of the sensor circuit substrate 31.

[0046] like Figure 1 and Figure 2 As shown, the main body 2 is provided with a front wall 85 that separates the motor housing 3 and the clutch housing 5, and a rear rib 86 that separates the motor housing 3 and the handle housing 7. The stator 21 is held in the front-rear direction by the rear rib 86, with the phase of each caulking fastening portion 77 of the terminal fittings 34A to 34C being on the upper side, and the axis is located at a position eccentric to the upper side of the motor housing 3. Therefore, the signal line 48 connected to the signal line connection portion 47 passes through the terminal unit 33 and is pulled out from the rear rib 86 to the rear, and passes through the upper side of the trigger switch 18 to be connected to the control circuit substrate 16. The power line 83 that is caulked and fastened to each caulking fastening portion 77 is also pulled out from the stator 21 to the rear, and passes through the upper side of the trigger switch 18 to be connected to the control circuit substrate 16.

[0047] In this manner, since the terminal unit 33 , the signal line 48 , and the power line 83 are not located outside the stator 21 , no portion protruding radially outward is generated on the motor case 3 .

[0048] On the other hand, the rotating shaft 27 of the rotor 22 is supported in a rotatable manner along the front-rear direction by a bearing 88 and a bearing 89, wherein the bearing 88 is held by a cylindrical bearing holder 87 supported by the front wall 85, and the bearing 89 is held at the center of the rear rib 86. A centrifugal fan 90 for cooling the motor is closely attached to the rear of the bearing 88 on the rotating shaft 27, and a plurality of air inlets (not shown) are formed on the radially outer side of the stator 21 on the motor housing 3, and a plurality of air outlets (not shown) are formed on the radially outer side of the centrifugal fan 90.

[0049] The rotating shaft 27 penetrates the bearing holder 87 and protrudes forward, and a pinion 91 ( Figure 2 ). A speed reduction mechanism (not shown) composed of two-stage front and rear planetary carriers is arranged in front of the bearing holder 87, and the pinion 91 meshes with the planetary gear of the rear planetary carrier, wherein the two-stage front and rear planetary carrier supports a plurality of planetary gears in an internal gear.

[0050] (Explanation of other main body structures)

[0051] exist Figure 1 In the embodiment, the clutch 6 has a rear cam 95 that rotates integrally with the planetary carrier on the front side of the speed reduction mechanism, and a front cam 97 that engages in the rotational direction via a cam ball 96. A main shaft 98 passes through the center of the clutch 6, and the main shaft 98 is engaged with the front cam 97 in the rotational direction via a ball 100 provided in a cam groove 99. In front of the front cam 97, a coil spring 102 is provided between a spring receiving portion 101 through which the main shaft 98 passes and the front cam 97, and urges the front cam 97 to a retreat position engaged with the cam ball 96, wherein the front cam 97 can move forward and backward relative to the main shaft 98 via the ball 100. The main shaft 98 protrudes coaxially into a small-diameter cylindrical joint 103, which is provided at the rear end of the front housing 10 and is held at the front end of the clutch housing 5. A threaded portion 104 that protrudes forward from the clutch housing 5 is formed at the front portion of the joint 103.

[0052] The front housing 10 has: a joint 103; and an inverted L-shaped elbow 105, which is arranged in front of the joint 103. The front housing 10 is connected to the clutch housing 5 by screwing a screw sleeve 106 installed on the outside of the rear end of the elbow 105 into the outer periphery of the threaded portion 104 of the joint 103.

[0053] In the front housing 10, an intermediate shaft 107 spanning the rear end of the joint 103 and the elbow 105 and having a bevel gear 108 at the front end is held by a plurality of bearings 109, 109... The hexagonal rear end of the intermediate shaft 107 protruding rearward is engaged with the hexagonal hole formed at the front end of the main shaft 98, thereby integrating the intermediate shaft 107 with the main shaft 98 in the rotational direction.

[0054] Furthermore, at the downwardly directed front end portion of the elbow 105 , the output shaft 12 is held by upper and lower bearings 110 , 110 and projects downward, and a bevel gear 111 provided on the output shaft 12 meshes with a bevel gear 108 of the intermediate shaft 107 .

[0055] Therefore, in the clutch 6, when the rear cam 95 rotates together with the front planetary carrier 93 that is rotated by the rotation shaft 27 being reduced to two stages, the front cam 97 rotates via the cam balls 96, and the main shaft 98 rotates via the balls 100 (rotational connection based on the clutch 6). Then, the intermediate shaft 107 that is integral with the main shaft 98 rotates, and the output shaft 12 rotates via the bevel gears 108 and 111.

[0056] On the other hand, if the load torque transmitted from the output shaft 12 to the main shaft 98 via the intermediate shaft 107 exceeds the pushing force (set torque) on the front cam 97 determined by the coil spring 102, the front cam 97 causes the cam groove 99 to move forward via the rolling ball 100, thereby releasing the engagement with the cam ball 96 and idling relative to the rear cam 95 (based on the rotation cutoff of the clutch 6).

[0057] Below the clutch 6, the sensor plate 112 is arranged so as to be movable in the front-to-back direction and to be urged toward the retracted position by the coil spring 113, and the engaging piece 114 protruding toward the main shaft 98 side is located in front of the front cam 97. Therefore, the sensor plate 112 moves forward integrally with the front cam 97 by abutting against the engaging piece 114 when the front cam 97 moves forward based on the rotation cutoff of the clutch 6. A magnet (not shown) is arranged at the rear of the sensor plate 112, and is connected to the control circuit substrate 16 through a wire (not shown) below the magnet, and a detection substrate having a Hall IC is arranged on the lower surface of the sensor plate 112 in the front-to-back direction. That is, when the clutch 6 operates and the sensor plate 112 moves forward, the change in the magnetic field of the magnet moving away from the front is detected by the Hall IC, and the detection substrate sends the detection signal to the control circuit substrate 16.

[0058] In addition, a rectangular window long in front and back is formed on the lower surface of the clutch housing 5 in front of the sensor plate 112, and an illumination substrate 115 is arranged in the window in a posture tilted obliquely forward, wherein the illumination substrate 115 is provided with two illumination lamps 116, 116 composed of LEDs in front and back. A cover 117 covering the illumination substrate 115 from below is provided on the lower side of the illumination substrate 115, and the cover 117 is fitted into the window from the inside, and the lower surface of the cover 117 parallel to the illumination substrate 115 is exposed. Therefore, the vicinity of the output shaft 12 can be reliably illuminated.

[0059] In front of the clutch 6, a notification light emitting unit 118 for notifying whether the screw is fastened is provided at the front end of the clutch housing 5. The notification light emitting unit 118 is composed of a circuit board 119 and a lens 121. The circuit board 119 carries three notification lamps 120, 120, ... at intervals of 120° in the circumferential direction along the front surface, and the lens 121 is assembled in front of the circuit board 119. Each lamp 120 has two LEDs, one green and one red.

[0060] The lens 121 is formed of a light-transmitting white resin and is annular in shape with an outer diameter substantially the same as the front end of the clutch housing 5. The rear end of the outer periphery of the lens 121 is embedded in the outside of the protrusion 122 of the clutch housing 5 and the circuit board 119 can be housed on the back. On the side surface of the lens 121, a tapered surface that tapers forward is formed over the entire periphery, and the lamps 120, 120 ... of the circuit board 119 are embedded in the groove formed on the rear surface of the lens 121.

[0061] On the other hand, an O-ring 123 is attached to the outside of the joint 103 , and when the lens 121 is fitted outside the front end surface of the clutch housing 5 , the O-ring 123 abuts against the inner peripheral side of the front surface of the lens 121 to prevent the lens 121 from falling off.

[0062] (Screwdriver action instructions)

[0063] In the screwdriver 1 configured as described above, when the driver bit attached to the output shaft 12 is pressed onto the tightening object, i.e., the screw, and the trigger 19 is pressed in this state to turn on the trigger switch 18, power is supplied from the battery pack 13 to drive the brushless motor 4. That is, the microcomputer of the control circuit board 16 obtains the rotation detection signal indicating the position of the sensor permanent magnet 30 of the rotor 22 output from the rotation detection element of the sensor circuit board 31, thereby obtaining the rotation state of the rotor 22, and controls the on / off of each switch element according to the obtained rotation state, thereby rotating the rotor 22 by causing current to flow sequentially through each coil 26 of the stator 21. The operation amount (pressing amount) of the trigger 19 is transmitted to the microcomputer as a signal, and the rotation of the rotor 22 is controlled according to the operation amount.

[0064] When the rotor 22 is rotated in this way, the rotating shaft 27 rotates and decelerates the rotation of the planetary carrier via the planetary gear, and the main shaft 98, the intermediate shaft 107, and the output shaft 12 are rotated via the clutch 6. Therefore, screw tightening can be performed by a screwdriver bit. When the screw tightening is performed and reaches the set torque based on the coil spring 102, the front cam 97 advances and cuts off the rotation transmission from the rear cam 95 in the clutch 6 as described above, so that the rotation of the output shaft 12 stops.

[0065] At this time, when the detection substrate detects the advancement of the sensor plate 112 based on the operation of the clutch 6 during the pressing operation of the trigger 19, the microcomputer of the control circuit substrate 16 determines that the screw fastening is "proper", and makes each lamp 120 of the circuit substrate 119 in the notification light emitting unit 118 emit green light. On the other hand, when the detection substrate does not detect the advancement of the sensor plate 112 (for example, when the pressing operation of the trigger 19 is stopped before the advancement of the sensor plate 112 is detected), the microcomputer of the control circuit substrate 16 determines that the screw fastening is "inappropriate", and makes each lamp 120 of the circuit substrate 119 emit red light.

[0066] Then, in the notification light emitting unit 118, the entire lens 121 emits green or red light due to the light emission of the three lamps 120, 120, ... located on the rear side of the elbow 105, and thus emits light across the front end surface and the entire circumference of the front end of the clutch housing 5. Therefore, regardless of the direction of the screwdriver 1, the operator can naturally recognize the light emission of the lens 121 without moving the line of sight from all directions to the position near the screw fastening part, and can easily confirm the determination result.

[0067] On the other hand, in addition to informing of the quality of threaded tightening, the notification light-emitting unit 118 can also be used to inform of a decrease in the remaining power of the battery pack 13 (flashing red light, etc.), an abnormal decrease in the voltage to the controller 15 (alternating red and green lights), and an abnormal temperature of the controller 15 (flashing red light, etc.).

[0068] Furthermore, when the centrifugal fan 90 rotates together with the rotating shaft 27 , the air sucked in from the air inlet cools the brushless motor 4 and is discharged from the air outlet.

[0069] When the trigger switch 18 is turned on, the illumination lamp 116 of the illumination board 115 is energized and lit by the control circuit board 16. Therefore, the front of the screwdriver head is illuminated through the cover 117, and workability can be maintained even in a dark place.

[0070] (Effects of the Invention Related to Arrangement of Terminal Fittings)

[0071] Thus, according to the screwdriver 1 of the above-mentioned embodiment, the stator 21, the rotor 22, and the terminal fittings 34A to 34C (conductor terminals), wherein the stator 21 has: a cylindrical stator core 23; a front insulator 24 and a rear insulator 25 fixed to the stator core 23; a coil 26 wound around the stator core 23 via the front insulator 24 and the rear insulator 25; and a welding terminal 32 (coil terminal) connected to the coil 26, the rotor 22 is rotatable relative to the stator 21, the terminal fittings 34A to 34C (conductor terminals) are integrally provided with the terminal unit 33 (resin component), are connected to the welding terminal 32, and are connected to the power supply line 83 (conductor), and the terminal fittings 34A to 34C are arranged at a position closer to the inner side than the outer diameter of the stator core 23 when viewed from the axial direction of the stator core 23, so that there is no portion protruding from the stator core 23 to the outside in the radial direction. Therefore, the motor case 3 housing the stator 21 can be made compact. In addition, by making the motor case 3 compact, it is easy to hold the motor case 3 with one hand while holding the handle case 7 with the other hand and use it as an auxiliary handle.

[0072] Furthermore, by removing the screws 81 and 82 , the terminal unit 33 and the sensor circuit board 31 are released from the stator 21 , so that the stator 21 and the controller 15 can be separated, thereby maintaining improved assemblability and repairability as before.

[0073] In particular, here, the terminal fittings 34A to 34C are connected to the welding terminal 32 by the screws 81 , so that a rational structure is formed in which the electrical connection and assembly of the terminal fittings 34A to 34C and the welding terminal 32 can be performed simultaneously.

[0074] In addition, since the welding terminal 32 is retained by the rear insulator 25, and the connecting piece 51 (connecting portion) with the terminal fittings 34A to 34C extends in the axial direction of the stator 21, and the welding terminal 32 is arranged at a position closer to the inside than the outer diameter of the stator core 23 when viewed from the axial direction of the stator core 23, the welding terminal 32 will not be exposed radially outward from the stator core 23, and can be easily connected to the terminal fittings 34A to 34C using the protruding connecting piece 51.

[0075] Furthermore, since the welding terminal 32 and the terminal fittings 34A to 34C are fixed by screws while overlapping in the radial direction of the stator 21 , the screw fixation of the two can be easily performed from the radial direction.

[0076] Furthermore, since the terminal unit 33 is formed in an annular shape, the terminal fittings 34A to 34C can be stably supported, and the terminal unit 33 can be easily assembled to the stator 21 .

[0077] Furthermore, the form of the connection portion provided in the welding terminal is not limited to the above-mentioned connection piece, and may be a hook shape, or may be a caulking fastening portion such as a terminal fitting.

[0078] The shape of the terminal unit may also be a polygon other than a hexagon, or a circle when viewed from above from the axial direction. In addition, the shape of the terminal unit is not limited to an annular shape, and may also be a C-shaped, semicircular shape, etc. when viewed from above. Therefore, the position and shape of the terminal fittings are not limited to the above-mentioned methods, and may be arranged uniformly along the circumference instead of in a straight line, and may adopt an end shape other than the caulking fastening part. The terminal fittings may also be insert molded (insert molding) into the terminal unit so that only the end of the caulking fastening part protrudes.

[0079] (Effects of the invention related to the structure for pulling out the power line and the signal line)

[0080] In addition, according to the screwdriver 1 of the above-mentioned embodiment, the stator 21 includes a cylindrical stator core 23, a front insulator 24 and a rear insulator 25 fixed to the stator core 23, a coil 26 wound around the stator core 23 via the front insulator 24 and the rear insulator 25, and a welding terminal 32 connected to the coil 26, the rotor 22 is rotatable relative to the stator 21, the power line 83 is indirectly connected to the welding terminal 32 via the terminal fittings 34A to 34C, the sensor circuit substrate 31 is fixed to the rear insulator 25, and the signal line 48 is connected to the sensor circuit substrate 31, and the power line 83 and the signal line 48 are pulled out in the same direction in the axial direction of the stator 21, so there is no wiring exposed radially outward from the stator core 23. Therefore, the motor case 3 housing the stator 21 can be made compact.

[0081] In the above-mentioned embodiment, the power line 83 is indirectly connected to the welding terminal 32 via the terminal fittings 34A to 34C of the terminal unit 33. However, in the invention in which the power line 83 and the signal line 48 are pulled out in the axial direction, the terminal unit and the terminal fittings are not necessary. Figure 7 As shown, the power line 83 may be directly connected to the connection piece 51 of each welding terminal 32 by brazing or screw fixing. In this case, the power line 83 and the signal line 48 may be pulled out to the outside of the stator 21 along the axial direction of the stator 21. Here, the shape of the connection piece and the connection method with the power line can also be appropriately changed.

[0082] (Effect of the invention related to positioning of the terminal unit and the sensor circuit substrate) Furthermore, according to the screwdriver 1 of the above-mentioned embodiment, there are a stator 21, a rotor 22, terminal fittings 34A to 34C and a sensor circuit substrate 31, wherein the stator 21 has: a cylindrical stator core 23; a front insulator 24 and a rear insulator 25, which are fixed to the stator core 23; a coil 26, which is wound around the stator core 23 via the front insulator 24 and the rear insulator 25; and a welding terminal 32, which is connected to the coil 26, The rotor 22 is rotatable relative to the stator 21, the terminal fittings 34A to 34C are integrally provided with the terminal unit 33, and are connected to the welding terminal 32, and are connected to the power line 83, and the sensor circuit substrate 31 is arranged between the terminal fittings 34A to 34C and the stator 21, and the terminal unit 33 having the terminal fittings 34A to 34C and the sensor circuit substrate 31 are positioned on the stator 21 by the same screws 82, so that the terminal unit 33 and the sensor circuit substrate 31 can be easily assembled. That is, the power line 83 can be easily assembled to the stator 21.

[0083] In addition, in the above-mentioned method, the head of the screw 82 is engaged with the through hole 68 of the mounting plate 67 of the terminal unit 33 for positioning, but the through hole 68 can also be made smaller and the mounting plate 67 can be screwed by the screw 82. The number and arrangement of the screws 81 and 82 can also be changed appropriately. The connection method is not limited to the two-series triangle connection method in the above-mentioned method, and can also be a two-parallel triangle connection method, a two-series or two-parallel star connection method (Y connection).

[0084] In addition, the target tool is not limited to an angle screwdriver, and can also be applied to other power tools such as screwdrivers whose output shaft is not orthogonal to the main shaft. Therefore, the main body is not limited to a straight line, and each invention can also be applied to a so-called T-type (gun-type) power tool in which the handle housing and the motor housing are connected orthogonally. For example, it can also be applied to a circular saw, a hammer, a reciprocating saw, etc.

[0085] Furthermore, the invention is not limited to DC tools powered by batteries, and each invention can also be applied to AC tools using commercial power. The motor may be a commutator motor or other motor other than a brushless motor.

Claims

1. An electric tool, characterized in that: It has a stator, a rotor and a lead terminal, wherein: The stator includes: a cylindrical stator core; an insulator fixed to the stator core; a coil wound around the stator core via the insulator; and a coil terminal connected to the coil. The rotor is rotatable relative to the stator, The lead terminal is integrally provided with the resin component and connected to the coil terminal and connected to the lead wire. The nut is held in the resin component in a posture facing the axis in the radial direction of the stator, and the coil terminal and the lead terminal are partially arranged on the radially outer side of the nut in a state of overlapping each other in the radial direction. The lead terminal is connected to the coil terminal by a screw that penetrates the coil terminal and the respective portions of the lead terminal and is screwed into the nut when viewed in the axial direction of the stator core, and is arranged at a position inner than the outer diameter of the stator core.

2. The electric tool according to claim 1, characterized in that: The coil terminal is retained by the insulator, and the connection portion of the coil terminal which becomes the part with the lead terminal extends along the axial direction of the stator and is arranged inside the resin component, and when viewed in the axial direction of the stator core, the coil terminal is arranged at a position closer to the inside than the outer diameter of the stator core.

3. The electric tool according to claim 1 or 2, characterized in that: The resin member is formed in a ring shape.

4. An electric tool, characterized in that: It has a stator, a rotor, a lead terminal, a power line, a sensor circuit substrate and a signal line, wherein: The stator includes: a cylindrical stator core; an insulator fixed to the stator core; a coil wound around the stator core via the insulator; and a coil terminal connected to the coil. The rotor is rotatable relative to the stator, The lead terminal is integrally provided with a ring-shaped resin member fixed to the insulator by screws and connected to a power line and to the coil terminal. The power line is directly or indirectly connected to the coil terminal, The sensor circuit substrate is fixed to the insulator between the resin member and the insulator. The signal line is connected to the sensor circuit substrate. The connection portion of the power line in the lead terminal is arranged at a position inside the outer diameter of the stator core when viewed from the axial direction of the stator core and protrudes in the axial direction of the stator, and the power line is pulled out along the axial direction. The signal line passes through the resin member and is pulled out in the same direction as the power line in the axial direction.

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