JP6635676B2 - Electric tool - Google Patents

Description

  The present invention relates to a power tool such as a driver drill using a motor as a drive source.

  In a power tool such as a driver drill, a tool using a motor as a drive source is known. For example, as disclosed in Patent Literature 1, a brushless motor has a plurality of (for example, six) teeth projecting through slots inside a stator core formed by stacking a plurality of steel plates, and each phase is assigned to each tooth. It is composed of a stator in which a coil to be formed is wound via an electric insulating member fixed to an end face of a stator core, and a rotor having a rotating shaft penetrating the stator and incorporating a permanent magnet.

JP 2015-56953 A

  In the electric insulating member, a stopper that rises in the axial direction of the stator core is provided at a tip that extends inward along the tooth to prevent the coil wound around the tooth from falling inward. However, this stopper portion may be deformed inward by the stress generated when the coil is wound, and may interfere with the rotor.

  Therefore, an object of the present invention is to provide a power tool which can prevent deformation of a stopper portion of an electric insulating member and thereby prevent interference with a rotor.

In order to achieve the above object, according to the first aspect of the present invention, a stator core having six teeth, a ring-shaped electric insulating member fixed to the stator core, and a tooth wound via the electric insulating member. A coil, and a terminal attached to the electrical insulating member and connected to the coil, the electrical insulating member having a stopper portion for preventing the coil from falling inward, and reinforcing means for reinforcing the stopper portion. On the other hand, on the electric insulating member, an L-shaped hook in a side view for holding a power supply line fixed to the terminal on the radially outer side of the electric insulating member is provided so as to project radially outward. It is characterized by the following.
According to a second aspect of the present invention, in the configuration of the first aspect, the reinforcing means is formed such that the stopper portion is formed in a U shape whose both ends protrude inward.
According to a third aspect of the present invention, in the configuration of the first or second aspect, the reinforcing means is such that a portion of the electrical insulating member extending along the teeth is made thicker in the axial direction of the stator core. Things.
According to a fourth aspect of the present invention, in the configuration of any one of the first to third aspects, the reinforcing means is provided on the side of the electrical insulating member to which the sensor circuit board of the brushless motor is fixed. .
According to a fifth aspect of the present invention, there is provided a stator core having a plurality of teeth, an electric insulating member fixed to the stator core, a coil wound around the teeth via the electric insulating member, and a magnetic member attached to the electric insulating member. A sensor circuit board on which the sensor is mounted, the electrical insulating member has a stopper for preventing the coil from falling inward, and a reinforcing means for reinforcing the stopper, while the sensor circuit board includes a stator core. Has a fixed piece that protrudes in the radial direction beyond the outer periphery of the fixed piece, and on the surface of the fixed piece, a connection portion of a lead wire that outputs a detection signal of a magnetic sensor is provided. An L-shaped hook for holding a power supply line to be connected is provided in a protruding manner in a side view, and a tip of the hook is brought into contact with a back surface of the fixing piece.

  ADVANTAGE OF THE INVENTION According to this invention, the deformation | transformation of the stopper part of an electrical insulation member can be prevented and interference with a rotor can be prevented.

It is a side view of a vibration driver drill. It is a rear view of a vibration driver drill. It is a longitudinal section of a vibration driver drill. It is an enlarged view of a main-body part. It is a perspective view of a stator. It is a top view of a stator. FIG. 7 is a view taken in the direction of arrow A in FIG. 6. FIG. 7 is a view on arrow B in FIG. It is a cross-sectional schematic diagram of a stator. It is an enlarged view of a fusing part. FIGS. 4A and 4B are schematic diagrams illustrating a method of winding a wire, wherein FIG. 4A illustrates a connection side and FIG. It is explanatory drawing which shows the connection state of a coil. (A) is a plan view of a stator using a heat radiating member, and (B) is a side view. (A) is a bottom view of a stator using a heat radiating member, and (B) is a side view. (A) is a sectional view taken along line AA of FIG. 14, and (B) is a sectional view taken along line BB. (A) is a plan view of a stator using a small-diameter sensor circuit board, and (B) is a bottom view. (A) is a side view of a stator using a small-diameter sensor circuit board, and (B) is a cross-sectional view taken along line CC. It is a perspective view of a front insulator of a modification. (A) is a plan view of a front insulator of a modified example, (B) is a sectional view taken along line DD, and (C) is a sectional view taken along line EE.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a side view of a vibration driver drill showing an example of a power tool, FIG. 2 is a rear view, FIG. 3 is a longitudinal sectional view, and FIG. 4 is an enlarged sectional view of a main body part. The vibration driver drill 1 has a handle 3 protruding downward from a main body 2 extending in the front-rear direction. A drill chuck 4 is provided at a front end of the main body 2 as a tool holding portion for holding a bit at a tip. At the lower end of the handle 3, a battery pack 5 serving as a power supply is mounted. The housing 6 here is formed by assembling left and right half housings 6a, 6b in which the rear half of the main body 2 and the handle 3 are connected to each other with screws 7, 7,.

  In the main body 2, an inner rotor type brushless motor 8 including a cylindrical stator 9 and a rotor 10 disposed inside the stator 9 and having a rotating shaft 11 mounted on the rotor 10 is accommodated in a rear portion. A gear assembly 12 having a spindle 13 protruding forward from the housing 6 is assembled in front of the brushless motor 8 so that the rotation of the rotating shaft 11 can be reduced and transmitted to the spindle 13. The drill chuck 4 is attached to a front end of the spindle 13. A switch 14 is accommodated below the main body 2 and above the handle 3, and a trigger 15 is projected forward. A forward / reverse switching button 16 for the motor is provided above the switch 14, and an LED 17 for irradiating the front of the drill chuck 4 is accommodated obliquely upward in front of the button.

  At the lower end of the handle 3, there is formed a mounting portion 18 on which the battery pack 5 is slidably mounted from the front. The mounting portion 18 includes a terminal block 19 having terminals 19a to which the battery pack 5 is electrically connected; A switch 14 and a controller 20 that includes a microcomputer for controlling the brushless motor 8 and six switching elements and are electrically connected to the stator 9 of the brushless motor 8 are housed therein. Reference numeral 21 denotes a strap locking portion provided on the rear surface of the mounting portion 18 using a screw boss, and 22 and 22 denote hanging hook attaching portions. In the battery pack 5, 23 is a rechargeable battery (here, 10.8 V provided with three rechargeable batteries (cells)), 24 is a terminal, 25 is a hook for retaining, and the hook 25 is released by a button 26 on the front. Operation is possible.

The gear assembly 12 is a cylindrical first gear case 27 located in front of the brushless motor 8, and is assembled in front of the first gear case 27 and has a two-stage cylindrical shape having a large diameter portion 29 and a small diameter portion 30. And a two-gear case 28. The first gear case 27 supports the rotating shaft 11 via a bearing 31, and protrudes a tip of the rotating shaft 11 to which the pinion 32 is attached into the gear assembly 12.
Inside the gear assembly 12, a planetary gear reduction mechanism 33 in which carriers 35A to 35C supporting a plurality of planetary gears 36A to 36C revolving in the internal gears 34A to 34C are arranged in three stages in the axial direction is accommodated. Then, the pinion 32 of the rotating shaft 11 meshes with the first stage planetary gear 36A. The second-stage internal gear 34B is rotatable and movable back and forth in the axial direction, and can mesh with the coupling ring 37 held in the large-diameter portion 29 at the advanced position.

  A speed switching lever 39 slidably provided in the housing 6 back and forth is connected to the internal gear 34B via a connecting member 38. When the speed switching lever 39 is slid backward, the internal gear 34B retreats via the connecting member 38 and meshes with the outer periphery of the first-stage carrier 35A while maintaining the mesh with the second-stage planetary gear 36B. . Therefore, the high-speed mode in which the second-stage deceleration is canceled is set. Conversely, when the speed switching lever 39 is slid forward, the internal gear 34B moves away from the carrier 35A via the connecting member 38, and the coupling ring 37 is kept engaged with the second-stage planetary gear 35B. And the rotation is regulated. Therefore, the low-speed mode in which the second-stage deceleration functions.

  Here, a vibration mechanism for imparting axial vibration to the spindle 13 is provided inside the small diameter portion 30 of the second gear case 28, and outside the small diameter portion 30, a predetermined load is applied to the spindle 13. A clutch mechanism for interrupting torque transmission to the spindle 13 is provided, and a switching operation described later causes a vibration drill mode in which the spindle 13 vibrates while rotating, a drill mode in which the spindle 13 rotates only, and a torque to the spindle 13 at a predetermined load. A clutch mode (driver mode) for interrupting transmission can be selected. Hereinafter, each mechanism will be described.

In the vibration mechanism, the spindle 13 is supported by front and rear bearings 40 and 41 in the small-diameter portion 30, and its rear end is spline-coupled to the third-stage carrier 35C. Between the bearings 40 and 41 of the spindle 13, a ring-shaped first cam 42 and a second cam 43 are coaxially provided from the front, respectively. The first cam 42 has a cam tooth on a rear surface and is spline-coupled to the spindle 13. The second cam 43 has cam teeth formed on the front surface thereof, is loosely inserted into the spindle 13, and is non-rotatably disposed in the small diameter portion 30.
Further, a plurality of steel balls 45, 45... Are held by a ring-shaped receiving plate 44 between the steel ball 45 and the first cam 42 in front of the first cam 42 and between the bearing 40. Is provided with a cam plate 46. An arm 47 extending rearward from the cam plate 46 is connected via a connecting plate 49 to a mode switching ring 48 rotatably assembled to the large-diameter portion 29 in front of the housing 6 to rotate the mode switching ring 48. As a result, the first cam 42 is slid rearward through the cam plate 46 to be engaged with the second cam 43 by the rotation of the connecting plate 49.

  In the clutch mechanism, a clutch ring 50 is rotatably mounted on the small diameter portion 30 in front of the mode switching ring 48. Inside the clutch ring 50, a screw feed plate 51 screwed to a screw portion formed on the outer periphery of the small diameter portion 30 is provided so as to be able to rotate integrally with the clutch ring 50 and move in the axial direction. A front receiving plate 52 that can move back and forth in the axial direction while being restricted by the small-diameter portion 30 is provided behind the small-diameter portion 30. Behind the front receiving plate 52, a pressing plate 54 that comes into contact with the front surface of the closing portion 53 between the large diameter portion 29 and the small diameter portion 30 and a rear receiving plate 55 in front of the pressing plate 54 are provided. A plurality of coil springs 56 are arranged at regular intervals in the circumferential direction between the plate 52 and the rear receiving plate 55.

  Further, behind the pressing plate 54, a plurality of steel balls 57, 57 are held in the closing portion 53 at equal intervals in the circumferential direction, and contact the front surface of the rotatable third-stage internal gear 34C. The inner gear 34C is in contact with a clutch cam (not shown) projecting from the front surface of the internal gear 34C in the circumferential direction. The biasing force of the coil springs 56, 56 is transmitted to the internal gear 34C via the steel ball 57, the pressing plate 54, and the rear receiving plate 55, whereby the rotation of the internal gear 34C is restricted. By rotating the clutch ring 50 and screwing the screw feed plate 51 and the front receiving plate 52 in the axial direction to change the axial length of the coil spring 56, the pressing force on the internal gear 34C can be changed.

Next, each operation mode will be described. First, at the first rotation position of the mode switching ring 48 in which the cam plate 46 has a phase in which the first cam 42 does not slide backward, the first cam 42 is in front of the second cam 43 and meshes with the second cam 43. do not do. Accordingly, the clutch mode is set in which the pressing force on the internal gear 34C can be changed by rotating the clutch ring 50.
When the brushless motor 8 is driven by pushing the trigger 15 in this clutch mode, the rotating shaft 11 rotates, the spindle 13 rotates via the planetary gear reduction mechanism 33, and the screw is screwed by the driver bit attached to the drill chuck 4. Tightening and the like can be performed. When the screw tightening advances and the load on the spindle 13 exceeds the pressing force of the coil spring 56 for fixing the internal gear 34C, the clutch cam of the internal gear 34C moves the steel ball 57, the pressing plate 54, and the rear receiving plate 55 forward. To rotate the internal gear 34C idly, thereby terminating the screw tightening (clutch operation).

Next, in the second rotation position where the mode switching ring 48 is rotated by a predetermined angle from the clutch mode, the regulating ring 58 provided on the mode switching ring 48 is engaged with the rear receiving plate 55 to advance the rear receiving plate 55. regulate. Therefore, the drill mode is set in which the forward movement of the pressing plate 54 is always restricted regardless of the magnitude of the pressing force of the coil spring 56.
When the spindle 13 is rotated in this drill mode, the fixed state of the internal gear 34C remains unchanged because the steel ball 57 does not climb over the clutch cam of the internal gear 34C regardless of the load on the spindle 13. The rotation of 13 continues. At this time, the first cam 42 does not slide backward, so that the spindle 13 does not vibrate.

Then, in the third rotation position where the mode switching ring 48 is further rotated by the predetermined angle from the drill mode, the cam plate 46 slides the first cam 42 backward. On the other hand, the engagement between the restriction ring 58 and the rear receiving plate 55 does not change. Therefore, the vibration mode is set in which the first cam 42 and the second cam 43 mesh with each other.
When the spindle 13 is rotated in the vibration mode, the first cam 42 that rotates integrally with the spindle 13 meshes with the second cam 43 fixed in the small-diameter portion 30, so that the spindle 13 vibrates. Note that the fixed state of the pressing plate 54 by the restriction ring 58 does not change, so that the rotation of the spindle 13 continues regardless of the load on the spindle 13.

The stator 9 of the three-phase brushless motor 8 is held by ribs 59, 59 formed on the inner surfaces of the half housings 6a, 6b with the longitudinal direction as the axis. The stator 9 has a ring-shaped front insulator 61 and a rear insulator 62, which are electric insulating members, attached to front and rear end surfaces of a stator core 60 formed by stacking a plurality of steel plates, and is provided with six protruding portions inside the stator core 60. The coils 63 are wound around the teeth 63, respectively. On the front surface of the front insulator 61, a magnetic sensor 66 such as a Hall IC for detecting the position of a permanent magnet 68 provided on the rotor 10 is provided. , 66... Are screwed.
A temperature detection element is arranged on the sensor circuit board 65, a temperature detection signal is input to the controller 20, and the controller 20 monitoring the signal stops the control of the brushless motor 8 at a predetermined temperature. Is also good. This makes it possible to effectively suppress the temperature rise of the brushless motor 8 of the vibration driver drill 1 of 10.8 V, at which the temperature tends to rise.

The rotor 10 is disposed around the rotation shaft 11 and has a substantially cylindrical rotor core 67 formed by stacking a plurality of steel plates, and four plate-like permanent magnets (sintered magnets) 68 fixed inside the rotor core 67. , 68,. The permanent magnets 68 are inserted into through holes formed so as to be located on four sides of a square centered on the rotation axis 11 in the cross section of the rotor core 67 and fixed by an adhesive and / or press-fitting.
The rear end of the rotating shaft 11 is supported by a bearing 69 held at the rear of the housing 6, and a centrifugal fan 70 is attached to a front part of the bearing 69. .. Are exhaust ports formed on the left and right side surfaces of the housing 6 at the position of the centrifugal fan 70, and intake ports 72, 72 are provided on the side surfaces of the housing 6 which are outside the stator 9 (FIG. 1).

  Further, a rear stopper 73 is provided between the rotor core 67 and the centrifugal fan 70. Thereafter, the stopper 73 is a disc made of brass and having the same outer diameter as the rotor core 67, and is fixed to the rotating shaft 11 coaxially with the rotor core 67. On the other hand, a front stopper 74 is provided inside the sensor circuit board 65 between the rotor core 67 and the front bearing 31. The front stopper 74 is a disc made of brass and having an outer diameter smaller than that of the rotor core 67, and is fixed to the rotating shaft 11 coaxially with the rotor core 67 and with a gap between the front stopper 74 and the rotor core 67. However, the outer diameter of the front stopper 74 is larger than the inner circle surrounded by the four permanent magnets 68, 68, so that the front stopper 74 is located in front of each permanent magnet 68. .

Here, the structure of the stator 9 will be described in detail with reference to FIGS. However, in the single stator 9 shown in FIGS. 5 to 8, the front insulator 61 side will be described as an upper side and the rear insulator 62 side will be described as a lower side.
On the extension of the teeth 63 on the outer periphery of the stator core 60, six axial grooves 75, 75..., Which are concave, are formed at equal intervals in the circumferential direction. The fitting pieces 76 are integrally formed in the axial direction from the rear insulator 62 and the rear insulator 62 (fitting). By press-fitting the fitting piece 76, the stator core 60 and the front and rear insulators 61 and 62 can be firmly integrated by resisting the distortion of the front and rear insulators 61 and 62.
On the side surface of the front insulator 61, a locking recess 77 is provided for locking a projection (not shown) provided on the inner surface of the housing 6, so that the stator 9 can be prevented from rotating and positioned in the front-rear direction.

  In the front insulator 61, of the six slots 78, 78... Formed between the teeth 63, 63,. The holding portions 82, 82,... Of the fusing terminals 81 for fusing the wires 79 of the coils 64, 64 and the power lines 80 of each phase are projected upward. In the holding portion 82, a pair of protrusions 83, 83 having a U-shape in plan view are arranged in the circumferential direction of the front insulator 61 so as to face each other, and are located above the ring-shaped upper end surface 61a of the front insulator 61. An L-shaped hook 84 for holding the power supply line 80 is provided on the outer side of each of the teeth 63 between the three holding portions 82, 82,. Have been. Two of the three power supply lines 80 are bound by a tape 109 at a position near the stator 9.

In addition, the outside of one tooth 63 located between the holding portions 82, 82 and the outside of two teeth 63, 63 located one by one in the circumferential direction from the tooth 63 (the apex position of the equilateral triangle). Are provided with three screw bosses 85, 85,... For screwing the sensor circuit board 65 at a height lower than the holding portion 82 and protruding above the upper end surface 61a of the front insulator 61. I have. A step having a receiving surface 87 at the same height as the screw boss 85 and having bosses 88A and 88B protruding above the receiving surface 87 is provided outside the teeth 63, 63 located between the screw bosses 85. The attached bosses 86A and 86B protrude. The boss 88A of the stepped boss 86A is disposed on a concentric circle slightly smaller than the concentric circle of the screw boss 85, and the boss 88B has a smaller diameter than the boss 88A.
In the rear insulator 62, circumferential guide ribs 89, 89,...

  The sensor circuit board 65 radiates between the notches 91, 91 by forming six notches 91 that are curved toward the through hole 90 of the rotating shaft 11 provided at the center at equal intervals in the circumferential direction. Are formed at equal intervals in the circumferential direction, and each notch 91 extends beyond the inner periphery of the stator core 60 and overlaps with each slot 78 in plan view. It is curved up. The tip of the fixing piece 92 slightly exceeds the outer circumference of the stator core 60, and two adjacent fixing pieces 92 (hereinafter, referred to as 92A and 92B when distinguishing) are the other four. It is formed longer than the two fixing pieces 92.

Of the six fixing pieces 92, three fixing pieces 92, 92... Located at the vertices of an equilateral triangle including one long fixing piece 92 </ b> B are respectively screwed to screw bosses 85 located on extensions of the teeth 63. The bosses 88A, 88B of the stepped bosses 86A, 86B are inserted into the fixing pieces 92 between the fixing pieces 92, 92 which are fixed and fixed with screws. On the upper surface of the remaining one fixed piece 92A, there are provided connection portions 94 of six lead wires 95A, 95A,... Which output detection signals of three magnetic sensors 66. A connector 96A is provided at the end of the lead wire 95A, and the lead wires 95A and 95B are connected to each other by coupling with a connector 96B provided on a lead wire 95B drawn out from the controller 20.
The three magnetic sensors 66 are arranged at predetermined intervals around the through hole 90 on the lower surface of the sensor circuit board 65. Here, as shown in FIG. Is noncircular on the circumference of the circle C1 on which the outermost periphery of the rotor 10 is located (outside the circle C2 on which the innermost periphery of the outer shape of the rotor 10 is located) and at the center of the slot 78 in the circumferential direction (the teeth). 63 (a phase shifted by 30 ° from the center line of 63).

In FIG. 9, the stator outer diameter S1 is φ38 (unit: mm, the same applies hereinafter), the stator inner diameter S2 is φ21, the teeth width S3 is 4.0, the back yoke width S4 is 2.0, the slot opening width S5 is 4.5, The rotor outer diameter S6 is φ20.
Note that the stator inner diameter S2 is in the range of φ20 to φ22 (ratio 0.53 to 0.58 when the stator outer diameter is 1), and the teeth width S3 is in the range of 4.0 to 4.4 (the same ratio of 0.1 to 0.5). 11 to 0.12), the back yoke width S4 is 2.0 to 2.2 (the same ratio is 0.05 to 0.06), and the slot opening width S5 is 2.5 to 4.5 (the same ratio is 0.07 to 0.07). 0.12), the rotor outer diameter S6 can be changed from φ19 to φ21 (the same ratio is 0.50 to 0.55). If the magnetic path is designed on the basis of the outer diameter of the stator in the IPM type rotor as described above, the output density can be increased, and even if the battery voltage is 10.8 V or the outer diameter of the stator is 40 mm or less, the rotation of the rotor can be reduced. The number can be as high as 24000 rpm or higher. However, if the battery voltage is 14.4 V, 18 V, or 36 V, high rotation of 30,000 rpm to 40,000 rpm is possible.

  The fusing terminal 81 is obtained by folding a band-shaped metal plate in two, forming L-shaped blade pieces 98 and 98 on both sides of one plate portion 97A, and folding the tip of the other plate portion 97B outward. By inserting the blade pieces 98, 98 into the two projections 83, 83 of the holding portion 82 from above with the two-folded portion facing down, the plate portion 97B is positioned outside as shown in FIG. It is held in a posture that is open in a letter shape. Here, a curled portion 99 for accommodating the power supply line 80 is formed inside the folded portion, and a bent portion 100 on which the wire 79 of the coil 64 is sandwiched is formed on the plate portion 97B above the curled portion 99. 100a is a folded portion of the plate portion 97B. Thus, the fusing terminals 81 are gathered and arranged on the half circumference of the stator 9 in plan view by the holding portion 82.

The power supply line 80 is stripped of only the stranded wire 80b that is fused to the fusing terminal 81, leaving the distal end 80a of the insulating coating. By leaving the tip 80a in this manner, the stranded wire 80b is not broken. In order to prevent the twisted wire from coming apart, besides leaving the tip of the insulation coating, the tip of the twisted wire 80b is covered with a heat-shrinkable tube, the tip is crimped with a splice terminal, soldering, welding, thermosetting. It can also be achieved by hardening the tip with resin.
Further, a lead terminal 101 is provided at the end of the power line 80 drawn from the stator 9, and the power lines are connected to each other by coupling with a lead terminal provided on a power line (not shown) drawn from the controller 20. It has become.

  The six coils 64, 64,... Are formed by sequentially winding one wire 79 around each tooth 63, and the coils 64, 64 for one phase are respectively connected to the fusing terminal 81. The crossover wire 102 connecting the diagonally located coils 64, 64 for one phase is wired not on the front insulator 61 side but on the rear insulator 62 side. Hereinafter, the winding method of the coil 64 will be described. When it is necessary to distinguish the three phases U, V, and W, the reference numerals of the respective components are denoted by U, V, and W, and each phase is paired. When the teeth 63 and the coils 64 are distinguished from each other, the description will be given with numerals such as 63U1, 63U2, 64U1, 64U2.

11A and 11B are schematic diagrams showing a winding method, in which FIG. 11A is on the connection side (front insulator 61 side), and FIG. 11B is on the anti-connection side (rear insulator 62 side). 81U, 81V, and 81W are fusing terminals. A symbol with a plus sign in the circle is a wire wound to the back side perpendicular to the paper surface, and a symbol with a black circle in the circle is a front wire perpendicular to the paper surface. Each shows a wire to be cut. Further, on the connection side and the anti-connection side, a left-handed direction will be described as left and a right-handed direction will be described as right.
First, on the connection side, the starting end 79a of the wire 79 is temporarily fixed to the fusing terminal 81U to which the U-phase power supply line 80U is temporarily fixed, and the coil 64U1 is formed by winding the tooth 63U1 located on the left side thereof from the right side. After pulling out to the left side of the teeth 63U1 on the anti-connection side, winding the crossover wire 102U indicated by the solid arrow around the guide rib 89 clockwise approximately half a turn, and winding the coil 64U2 around the diagonal teeth 63U2 from the right side. Form. Then, the wire 79 is pulled out from the left side of the tooth 63U2 on the connection side, and temporarily fixed to the fusing terminal 81W to which the W-phase power line 80W is temporarily fixed.

  Next, a coil 64W1 is formed by winding the tooth 64W1 around the tooth 63W1 adjacent to the left side of the fusing terminal 81W from the right side, and then pulled out to the left side of the tooth 63W1 on the non-connection side, and a crossover 102W indicated by a dotted line outside the guide rib 89. Is wound clockwise approximately half a turn, and then wound around the diagonal teeth 63W2 from the right side to form a coil 64W2. Thereafter, the wire is pulled out to the left side of the tooth 63W2 on the same anti-connection side, and the crossover wire 102W is wound clockwise approximately half a circle outside the guide rib 89, and then pulled out to the left side of the diagonal tooth 63W1 on the connection side, and the V phase Is temporarily fixed to the temporarily fixed fusing terminal 81V. In other words, the wires 79 forming the W-phase coils 64W1 and 64W2 are routed in the clockwise direction between the teeth 63W1 and 63W2 on the rear insulator 62 side by approximately a half turn.

Next, a coil 64V1 is formed by winding from the right side to the tooth 63V1 adjacent to the left side of the fusing terminal 81V, and then pulled out to the left side of the tooth 63V1 on the non-connection side, and a crossover line indicated by a dashed line outside the guide rib 89. After winding 102V clockwise approximately half a turn, it is wound around the diagonal teeth 63V2 from the right side to form a coil 64V2. Then, on the same anti-connection side, pull out to the left side of the tooth 63V2, and around the guide rib 89, route the crossover wire 102V clockwise by approximately half a turn, and then pull out to the left side of the diagonal tooth 63V1 on the connection side, and to the left side. The terminal 79b is temporarily fixed to the adjacent fusing terminal 81U. In other words, the wires 79 forming the V-phase coils 64V1 and 64V2 are also routed in the counter-clockwise direction between the teeth 63V1 and 63V2 on the rear insulator 62 side by approximately a half turn. Actually, as shown in FIGS. 7 and 8, each crossover 102 is wired outside the guide rib 89 so as to overlap in the axial direction.
Finally, by fusing the power supply line 80 and the wire 79 at each fusing terminal 81, as shown in FIG. 12, the stator 9 in which the coils 64, 64 of each phase wound in series are delta-connected is obtained.

  In the stator 9 to which the connection is completed and the sensor circuit board 65 is attached, the sensor circuit board 65 is higher than the upper end face 61a of the front insulator 61 by the upper surface of the screw boss 85 and the receiving surfaces 87 of the stepped bosses 86A and 86B. It is supported at a position orthogonal to the axis of the stator 9. At this time, the tips of the hooks 84 also contact the lower surfaces of the long fixed pieces 92A, 92B to support the fixed pieces 92A, 92B. Here, since the crossover wire 102 between the coils 64 of each phase is wired on the anti-connection side, a sufficient gap is formed between the front insulator 61 and the sensor circuit board 65. When the sensor circuit board 65 is fixed, the holding portions 82 and the fusing terminals 81 penetrate through the cutout portions 91 of the sensor circuit board 65 and protrude above the sensor circuit board 65. The slots 78 between the slots 63 are exposed in the cutouts 91 of the sensor circuit board 65 (FIG. 6).

Here, since the power supply line 80 is held by the hook 84 and the fixing piece 92, the power supply line 80 becomes difficult to move and also serves as a guide for wiring. Further, since the fixing piece 92A to which the lead wire 95A of the magnetic sensor 66 is connected is supported by the hook 84, the lead wire 95A is not easily broken. Furthermore, since the radial distance from the axis of the brushless motor 8 to the center of the boss 88A is smaller than the radial distance from the axis to the center of the screw 93, the vibration of the sensor circuit board 65 is reduced.
Further, since the sensor circuit board 65 is attached with the screws 93, even if one of the sensor circuit board 65 and the stator 9 breaks down, the sensor circuit board 65 can be individually repaired by removing the sensor circuit board 65.

  This stator 9 is incorporated in the housing 6 in such a phase that the fusing terminals 81 are located on the lower half side of the stator 9. Thus, the power supply lines 80 of each phase connected to the fusing terminal 81 are wired to the controller 20 at the shortest distance without passing through the left and right outer sides of the stator 9. Therefore, the housing 6 does not increase in the radial direction, the compactness can be maintained, and the length of the wiring can be reduced. Further, since the power supply line 80 and the lead wire 95A of the magnetic sensor 66 can be separated from the controller 20 by the connector 96A and the plug terminal 101, the stator 9 and the controller 20 can be individually repaired or replaced, thereby reducing costs. . Note that other terminals and connectors can be used for connection between lead wires and between power supply lines.

In the vibration driver drill 1 configured as described above, when the trigger 15 is pushed and the switch 14 is turned on, the microcomputer of the controller 20 causes the permanent magnet of the rotor 10 to be output from the magnetic sensor 66 of the sensor circuit board 65. The rotation state of the rotor 10 is obtained by obtaining a rotation detection signal indicating the position 68, and ON / OFF of each switching element is controlled in accordance with the obtained rotation state. The rotor 10 is rotated by supplying an exciting current in order. Therefore, since the rotating shaft 11 rotates to rotate the spindle 13 via the planetary gear reduction mechanism 33, it can be used in the operation mode selected by the tip tool held by the drill chuck 4.
Here, since the magnetic sensor 66 is arranged at the center of the slot 78 of the stator 9, the energizing timing for supplying the exciting current from the controller 20 to the coil 64 of each phase in either the forward or reverse rotation direction is advanced. Advance phase control advanced by 30 ° can be performed. This arrangement of the magnetic sensor 66 makes it difficult for the sensor magnetic flux to be affected by the stator magnetic flux, so that the sensing accuracy of the rotor 10 does not decrease.

When the centrifugal fan 70 rotates with the rotation of the rotating shaft 11, the outside air is sucked in from the intake port 72 on the side surface of the housing 6, passes through the outside and inside of the stator 9 (between the rotor 10), and is discharged from the exhaust port 71. As a result, the brushless motor 8 is cooled. At this time, in the stator 9, the slot 78 is exposed in the front view by the cutout portion 91 of the sensor circuit board 65, and the crossover wire 102 is not routed between the sensor circuit board 65 and the front insulator 61. The air passing inside 9 can smoothly pass through the slots 78 on both sides of each coil 64 without being disturbed by the sensor circuit board 65. Therefore, each coil 64 is also effectively cooled. Further, since each fusing terminal 81 is located between the fixing pieces 92, each fusing terminal 81 is effectively cooled by the air passing through the cutout 91.
On the other hand, in the rotor 10, the front stopper 74 and the rear stopper 73 are provided on the front and rear, so that the movement of each of the permanent magnets 68 in the front and rear direction is regulated, and the falling off from the rotor core 67 is effectively prevented.

As described above, according to the vibration driver drill 1 of the above-described embodiment, since the magnetic sensor 66 is provided at a position corresponding to the center of the slot 78 in the rotation direction of the rotor 10, the coils 64 of each phase are connected in series. Even with the brushless motor 8 that is delta-connected, the advance phase control of the advance angle of 30 ° can be performed without being affected by the stator magnetic flux and without performing the advance angle control on software. Therefore, the motor efficiency can be improved.
Further, by attaching the sensor circuit board 65 to the front insulator 61 provided on the end face of the stator 9, the sensor circuit board 65 can be easily attached to an appropriate position using the front insulator 61.

  In the above embodiment, the magnetic sensor 66 is arranged at the center of the slot 78 so as to obtain an advance angle of 30 °. However, it is not necessary that the magnetic sensor 66 is strictly located at the center of the slot 78. For example, the angle may be slightly shifted from the center. However, in this case, it is necessary to perform the correction control on the software so that the advance angle is 25 ° by the controller 20 in the reverse direction. Further, the magnetic sensor 66 may be disposed on the surface opposite to the stator 9, and the coil 64 may be a delta-connected parallel winding.

  On the other hand, when the rotation speed of the rotor 10 is set to 24000 rpm or more as described above, the amount of electricity supplied to the coil 64 increases, and the temperature rises. As the heat radiating member, a metal heat radiating ring having an inner diameter larger than the area where the magnetic sensor 66 is disposed is provided between the sensor circuit board 65 and each of the coils 64, as in a stator 9A shown in FIGS. A structure is conceivable in which the heat dissipating ring 103 is adhered to the upper end surface of each coil 64 with an adhesive having thermal conductivity and insulation. Reference numerals 103a, 103a,... Indicate through holes provided in the heat radiating ring 103 at the positions of the slots 78. The through holes 103a secure the flow of air passing through the slots 78 and make contact between the heat radiating ring 103 and air. The heat dissipation effect is improved by increasing the area.

By providing the heat radiating ring 103 that indirectly contacts the coil 64 in this manner, even if the rotor 10 rotates at a high speed, it is possible to suppress the temperature rise of the coil 64.
The heat dissipating member is not ring-shaped, but is provided with a plurality of arc-shaped members that straddle a plurality of coils, are provided separately for each coil avoiding slots, and are provided with fins on the surface or irregularities. Or the surface area can be further increased by providing a surface. It may be provided on the rear side instead of the front side of the stator.

  Further, the sensor circuit board does not need to be substantially the same size as the front insulator, and is a ring-shaped sensor circuit board 65A having an outer diameter reduced to the inside of the coil 64 as in a stator 9B shown in FIGS. You can also. The front insulator 61 has a root portion 105 projecting axially along the front surface of each tooth 63 to cover the front surface of the tooth 63, and extends from the tip of the root portion 105 circumferentially and upward to the inside of the coil 64. , Each of which has a stopper portion 106 for preventing the tilting of the sensor circuit board 65A, a tongue-shaped inner portion 107 for receiving the outer periphery of the sensor circuit board 65A is provided at the lower end of the inner periphery of each stopper portion 106. Are protruded from each other. Therefore, the sensor circuit board 65A is fixed by press-fitting, bonding with an adhesive, screwing, or the like in a state in which the sensor circuit board 65A is pressed from above so as to fit inside the respective stopper sections 106 and the outer periphery thereof is in contact with the inner section 107. be able to. In this case as well, the magnetic sensor 66 may be disposed substantially at the center of the slot 78, but the lead wire is drawn out from the upper side or the lower side of the sensor circuit board 65A to the outside through the slot 78 and is wired in the same direction as the power supply line 80. do it.

By arranging the sensor circuit board 65A smaller in diameter than the front insulator 61 inside the coil 64, the detection accuracy of the magnetic sensor 66 is improved, and the axial length and the radial dimension of the brushless motor 8 are reduced. And compactness can be expected.
Note that the inner portion does not need to be provided in all stopper portions, and can be provided in, for example, every other stopper portion as long as the sensor circuit board can be fixed, and the shape can be appropriately changed.
Further, in the above embodiment and the modified examples of FIGS. 13 to 17, the front insulator 61 is provided with the sensor circuit boards 65 and 65A, but the rear insulator 62 is provided with the sensor circuit boards 65 and 65A and the crossover wire 102 is connected to the front insulator 61. It is also possible to wire on the side.

  The form of the front insulator can be changed as shown in FIGS. In the case of the shape of the front insulator 61 described above, the stopper portion 106 of the insulating tooth 104 may be deformed inward by the stress generated when the coil 64 is wound, and may interfere with the rotor 10. Therefore, in the front insulator 61A, a concave portion 108 is formed in the stopper portion 106 of each of the insulating teeth 104 so as to surround the center of the protruding end surface in the axial direction. The stopper 106 is reinforced in a U-shape in which both front and rear ends in the rotor rotation direction protrude inward (on the axial center side) relative to the portion.

As described above, according to the vibration driver drill 1 of the above embodiment, the front insulator 61 of the stator 9 is provided with the reinforcing means for reinforcing the stopper portion 106, so that the strength of the stopper portion 106 is increased, and the stress at the time of coil winding is increased. Thus, the possibility of inward deformation is reduced. Further, even if it is deformed, the distance from the rotor 10 is ensured by the concave portion 108, so that it does not easily interfere with the rotor 10.
In particular, since the stopper portion 106 is formed in a U-shape with both ends protruding inward as reinforcement means, reinforcement can be easily performed.
The reinforcing means may have a configuration in which the stopper portion 106 is formed in a U-shape, and the root portion 105 extending along the teeth 63 is made thicker in the axial direction of the stator 9. In this case, in addition to the same thickness in the radial direction, the thickness may be gradually or gradually increased toward the center. Of course, a combination with a U-shape is also possible.

Further, here, a stator core 60 having six slots 78 and a post insulator 62 fixed to the stator core 60 and holding a plurality of crossover wires 102 between the coils 64 in the axial direction of the stator core 60. , A guide rib 89 for guiding the crossover wire 102 in a direction opposite to the winding direction of the coil 64, a rotor 10 disposed inside the stator 9, and a drill chuck 4 driven by the rotor 10. With this arrangement, the crossover 102 can be wired by the guide rib 89 without play.
Furthermore, since the coil 64 is wound around the teeth 63 from one side in the circumferential direction of the stator core 60 and ends on the other side, the coil 64 and the crossover 102 can be smoothly connected. .

In the above embodiment, the projection provided on the inner surface of the housing is engaged with the engagement concave portion provided on the side surface of the front insulator to prevent the stator from rotating and position in the front-rear direction. Alternatively, in addition to this, a protrusion may be provided on the outer surface of the stator core, and the protrusion may be engaged with a recess provided on the inner surface of the housing to prevent rotation of the stator and position in the front-rear direction.
Furthermore, the lead wire of the magnetic sensor is not limited to being connected on the extension of the teeth in the radial direction of the stator, but may be connected on the extension of the slot.
In addition, the magnetic sensor can be disposed at a position (outside of the position in FIG. 9) that overlaps the tip of the tooth in the axial direction.
In the above embodiment, only the magnetic sensor is mounted on the sensor circuit board, but a switching element forming an inverter circuit may be provided. In this case, the switching element can be arranged at any position where the switching element overlaps the magnetic sensor in the axial direction and where it does not overlap.

  In addition, the present invention is applicable not only to the vibration driver drill but also to other models such as an impact driver and a grinder as long as the power source is a brushless motor. The position and orientation of the motor within the housing can also be changed as appropriate. Further, in the above embodiment, the coil is formed by one wire (winding), but it is also possible to form the coil by a plurality of windings such as two or three. The brushless motor can also increase or decrease the number of poles or slots, and the present invention can be adopted even if the magnet is curved along the rotation direction or the SPM method is used in which the magnet is mounted on the surface of the rotor.

And here, the following invention can be grasped.
(1) An electric tool in which the number of rotations of a brushless motor as a driving source is from 30,000 rpm to 40,000 rpm.
(2) A power tool having a battery voltage of 10.8 V as a power source and a motor rotation speed of 24000 rpm or more.
(3) An electric tool in which the outer diameter of the stator of the brushless motor serving as the driving source is 40 mm or less and the rotation speed is 24000 rpm or more.
(4) a stator core;
An electrical insulating member (the front insulators 61 and 61A in the above embodiment) fixed to the stator core;
A coil wound around the stator core via the electrical insulating member,
The electric insulating member has a protruding portion (stopper portion 106 in the above-described embodiment) that is disposed inside the coil.
An electric tool in which a sensor circuit board is screwed to the protrusion.
(5) a stator core;
An electrical insulating member (front insulator) fixed to the stator core,
A coil wound around the stator core via the electrical insulating member,
The electrical insulating member has a protruding portion arranged on the inner side than the coil,
An electric tool in which a sensor circuit board is arranged inside the projecting portion.
(6) a stator core;
An electrical insulating member (front and rear insulators) fixed to the stator core,
A coil wound around the stator core via the electrical insulating member,
The electrical insulating member has a protruding portion arranged on the inner side than the coil,
An electric tool in which an electric component is arranged inside the projecting portion.
As the electric material parts, in addition to the sensor circuit board, a crossover, a fusing terminal, a lead, a switching terminal, a short-circuit member, a capacitor, a temperature sensor, and the like can be considered, and a plurality of these are arranged inside the protruding portion. You can also.
Further, inventions other than the invention in which the magnetic sensor is disposed substantially at the center of the slot are applicable to a Y-connected stator.

  1. Vibration driver drill, 2. Body, 3. Handle, 4. Drill chuck, 5. Battery pack, 6. Housing, 8. Brushless motor, 9, 9A, 9B, stator, 10. ..Rotor, 11 rotary shaft, 12 gear assembly, 13 spindle, 20 controller, 33 planetary gear reduction mechanism, 60 stator core, 61, 61A front insulator, 62 Rear insulator, 63 teeth, 64 coils, 65, 65A sensor circuit board, 66 magnetic sensor, 67 rotor core, 68 permanent magnet, 70 centrifugal fan, 71 exhaust port , 72..inlet, 75..groove, 76..fitting piece, 78..slot, 79..wire, 80..power line, 81..fusing terminal, 82 .. Holding part, 89 guide rib, 95A, 95B lead wire, 96A 96B connector, 101 terminal, 103 heat radiation ring, 104 insulating teeth, 105 root part, 106 base · Stopper part, 107 · · · inner part, 108 · · · recess.

Claims (5)

A stator core having six teeth,
A ring-shaped electric insulating member fixed to the stator core,
A coil wound around the teeth via the electrical insulating member,
A terminal attached to the electrical insulating member and connected to the coil,
The electric insulating member has a stopper for preventing the coil from falling inward, and includes a reinforcing unit for reinforcing the stopper.
An L-shaped hook in a side view for holding a power line fixed to the terminal at a radially outer side of the electrical insulating member is provided on the electrical insulating member so as to project outward in the radial direction . An electric tool characterized by the above-mentioned.   The power tool according to claim 1, wherein the reinforcing means is configured such that the stopper portion is formed in a U shape whose both ends protrude inward.   The power tool according to claim 1, wherein the reinforcing means is formed by thickening a portion of the electrical insulating member extending along the teeth in the axial direction of the stator core.   The power tool according to any one of claims 1 to 3, wherein the reinforcing means is provided on a side of the electrical insulating member to which a sensor circuit board of the brushless motor is fixed. A stator core having a plurality of teeth,
An electrical insulating member fixed to the stator core,
A coil wound around the teeth via the electrical insulating member,
A sensor circuit board mounted with a magnetic sensor attached to the electrical insulating member ,
The electric insulating member has a stopper for preventing the coil from falling inward, and includes a reinforcing unit for reinforcing the stopper .
The sensor circuit board has a fixed piece that protrudes radially beyond the outer periphery of the stator core, and on the surface of the fixed piece, a connection portion of a lead wire that outputs a detection signal of the magnetic sensor is provided. ,
An L-shaped hook for holding a power line connected to the coil is projected from the electrical insulating member, and a tip of the hook is brought into contact with a back surface of the fixing piece. An electric tool characterized by the above-mentioned.

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