JP2015054395A - Electric tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power tool which can be made compact in size.SOLUTION: A driver drill includes: a brushless motor 17 which is composed of a stator 18 having a stator core 20, a front insulator 21 engaged with one end side of the stator core 20, a rear insulator 22 engaged with the other end side of the stator core 20, a coil 23 wound around the front insulator 21 and the rear insulator 22, a fusing terminal which is connected to the front insulator 21, and connected with a winding of the coil 23, and a short-circuit member 25 which is connected to the front insulator 21, and short-circuits the fusing terminal; and a rotor 19 having a permanent magnet 63 and a rotating shaft 61 fixed with the permanent magnet 63; and a tip tool holding part driven by the rotor 19.

Description

  The present invention relates to an electric tool such as a driver drill provided with a motor as a drive source.

  As disclosed in Patent Document 1, a power tool is well known that is equipped with a motor such as a brushless motor. This motor has a structure corresponding to the model of the power tool (light load model, heavy load model). Is different. For example, some have a motor having a structure in which a lead wire (power line) is directly connected to a fusing terminal.

JP2011-45201A

  Therefore, although the motor for a light load model is small and saves space, there is a problem that a large current cannot flow. On the other hand, a motor for a heavy load model can pass a large current, but is larger than that for a light load model, and thus is not suitable for a compact product.

  Accordingly, an object of the present invention is to provide an electric tool that can be made compact.

In order to achieve the above object, the invention described in claim 1 includes a stator core, a first insulator disposed on one end side of the stator core, a second insulator disposed on the other end side of the stator core, and a first insulator. And a coil wound around the second insulator, a first fusing terminal and a second fusing terminal fixed to the first insulator and connected to the coil winding, and a first fusing terminal fixed to the first insulator And a stator having a short-circuit member that short-circuits the second fusing terminal,
A brushless motor comprising a rotor having a permanent magnet and a rotating shaft to which the permanent magnet is fixed;
And a tip tool holding portion driven by a rotor.
According to a second aspect of the present invention, in the configuration of the first aspect, the short-circuit member is fixed to the first insulator by a screw.
According to a third aspect of the present invention, in the configuration of the first or second aspect, a power supply line is connected to the short-circuit member.
According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the second insulator is provided with a fan fixed to the rotating shaft.
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the first fusing terminal and the second fusing terminal are soldered to a short-circuit member.
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the short-circuit member is formed with a slit into which the first fusing terminal and the second fusing terminal are inserted. Is.
In order to achieve the above object, a seventh aspect of the present invention includes a stator core, a first insulator disposed on one end side of the stator core, a second insulator disposed on the other end side of the stator core, and a first insulator. And a coil wound around the second insulator, six first to sixth fusing terminals fixed to the first insulator and connected to the coil winding, and a short circuit connected to the first to sixth fusing terminals. A stator having a member and four first to fourth screws for fixing the short-circuit member to the first insulator;
A brushless motor comprising a rotor having a permanent magnet and a rotating shaft to which the permanent magnet is fixed;
And a tip tool holding portion driven by a rotor.
According to an eighth aspect of the present invention, in the configuration of the seventh aspect, the first fusing terminal is disposed between the first screw and the second screw, and the second fuse is disposed between the second screw and the third screw. A fourth fusing terminal is disposed between the third screw and the fourth screw, and the fifth fusing terminal and the third fusing terminal are disposed between the third screw and the fourth screw. Six fusing terminals are arranged.
In order to achieve the above object, a ninth aspect of the present invention provides a stator core, a first insulator disposed on one end side of the stator core, a second insulator disposed on the other end side of the stator core, and a first insulator. And a brushless motor having a coil wound around the second insulator and a rotation detecting element arranged on the first insulator side, the coil being short-circuited on the second insulator side. is there.

  According to the present invention, downsizing can be achieved by using a small and space-saving motor. In particular, since the fusing terminal and the short-circuit member are separated, the short-circuit member can be soldered to the fusing terminal after the coil is wound, and the short-circuit member does not get in the way.

It is a general view of a driver drill. It is a longitudinal cross-sectional view of a main body rear part. It is a perspective view from the front of a brushless motor. It is a perspective view from the back of a brushless motor. It is a disassembled perspective view of a brushless motor. It is explanatory drawing of a sensor circuit board, (A) is a front view, (B) is a BB sectional drawing. It is explanatory drawing of a brushless motor, (A) shows a front surface, (B) shows a side surface, (C) shows a back surface, respectively. (A) is a perspective view from the front of a short circuit member, (B) is a perspective view from the back of a short circuit member. It is explanatory drawing of a short circuit member, (A) shows a front surface, (B) shows a side surface, (C) shows a back surface, respectively. It is a disassembled perspective view of a short circuit member. It is explanatory drawing which shows arrangement | positioning of a sheet metal member. It is a figure which shows the connection state of a coil. It is the sectional view on the AA line of FIG. (A) is a perspective view from the front of a cylindrical housing, (B) is a perspective view from the back of a cylindrical housing. (A) is a front view of a cylindrical housing, (B) is CC sectional view taken on the line. (A) is a DD line sectional view, (B) is an EE line sectional view. It is a perspective view of the brushless motor which changed the direction of the sensor circuit board. It is a longitudinal cross-sectional view of a grinder. It is a perspective view of the stator which changed the attachment position of the sensor circuit board. It is explanatory drawing of the stator which changed the attachment position of the sensor circuit board, (A) shows a back surface, (B) shows a side surface, (C) shows a front surface, respectively. It is FF sectional view taken on the line. It is explanatory drawing of the example of a change of a front insulator, (A) is a front view, (B) is a GG sectional view. It is explanatory drawing of the example of a change of a rear insulator, (A) is a front view, (B) is a HH sectional view taken on the line.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall view of a driver drill as an example of an electric tool, FIG. 2 is a longitudinal sectional view of a rear portion of a main body, and a driver drill 1 is a T-shape in which a handle 3 is formed downward on a main body 2 extending in the front-rear direction. A battery pack 5 serving as a power source is mounted on the mounting portion 4 formed at the lower end of the handle 3.
The housing of the main body 2 is screwed from the front in front of a cylindrical main body housing 6 that houses a brushless motor 17 and a planetary gear reduction mechanism 72 (right side in FIG. 1) that houses a clutch mechanism and a spindle. 8, the cap housing 9 is assembled to the rear side of the main body housing 6 with screws 10 and 10 at two locations from the rear to the upper and lower sides. The coupling surface of the main body housing 6 and the cap housing 9 includes a ring-shaped convex portion 6c formed on the rear surface of the main body housing 6 including a screw boss into which the screw 10 is screwed, and a concave portion 9a formed on the front surface of the cap housing 9. It is a cantilever connection that fits in. A mode switching ring 11 and a clutch adjustment ring 12 are provided in front of the front housing 7, and a chuck 13 attached to the spindle is provided in front of the clutch adjustment ring 12. The handle 3 is connected to the main body housing 6 and is formed by assembling the left and right half housings 6a, 6b with screws 14, 14,. Reference numeral 15 denotes a trigger provided on a switch accommodated in the handle 3, and 16 denotes a motor forward / reverse switching button. A light (not shown) for irradiating the front of the chuck 13 is provided above the trigger 15.

  The brushless motor 17 accommodated in the rear part of the main body housing 6 is an inner rotor type composed of a stator 18 and a rotor 19, and the stator 18 is a cylindrical shape formed of a plurality of laminated steel plates as shown in FIGS. The stator core 20, front insulators 21 and rear insulators 22 provided on axially front and rear end faces of the stator core 20, and six coils 23, 23... Wound around the stator core 20 via the front and rear insulators 21 and 22, A sensor circuit board 24 and a short-circuit member 25 are attached to the front insulator 21.

First, the stator core 20 includes six teeth 26, 26,... Projecting toward the axial center, and six slots 27, 27,.
The front insulator 21 is an integrally molded product having a ring shape with the same diameter as the stator core 20, and protrudes toward the axial center on the inner peripheral side, and has six protruding portions 28, 28, which are positioned continuously in front of the teeth 26 of the stator core 20. -Forming. Further, six fitting portions 29, 29... That fit into the slots 27 of the stator core 20 are projected on the back side of the front insulator 21, and the front surface is provided with a position corresponding to the fitting portion 29, which will be described later. Six sets of holding portions 30, 30... For the fusing terminal 42 are provided. This holding part 30 is a pair of protrusions 31 having grooves 32 arranged at predetermined intervals so that the grooves 32 face each other, and a screw hole is provided between the holding parts 30 in the center. A screw boss 33 having a flange portion 34 extending at the base is protruded.

Further, as shown in FIG. 7, a pair of concave portions 35 and 35 as positioning portions are respectively formed on the left and right side portions of the front insulator 21, and on the upper and lower sides sandwiching the concave portions 35 and 35, A pair of triangular first cutout portions 36, 36 are formed as positioning portions. A square-shaped second cutout portion 37 as a positioning portion is formed at the upper center of the front insulator 21. These concave portions 35, first cutout portions 36, and second cutout portions 37 are configured such that the rear surfaces thereof are closed by the stator core 20 (FIG. 7B).
Next, the rear insulator 22 is also formed in a ring shape having the same diameter as the stator core 20, and protrudes toward the axial center side on the inner peripheral side, and six protruding portions 38, 38. -Forming. Further, six fitting portions 39 that fit into the slots 27 of the stator core 20 protrude from the front side of the rear insulator 22. Further, curved lateral cutout portions 40, 40 are formed on the left and right sides of the rear insulator 22, and chamfered portions 41, 41 that are cut out linearly are formed at the upper and lower centers.

A fusing terminal 42 is held by each holding portion 30 of the front insulator 21. The fusing terminal 42 is formed by folding a band-shaped metal fitting in half. One end portion 43 is bent at an intermediate portion in a convex shape, and a blade piece 45 having an L-shaped cross section is formed on both side edges of the other end portion 44. 45 are bent. Therefore, when the bent side of each fusing terminal 42 is inserted into the holding portion 30 and the blade pieces 45 are fitted into the groove portions 32 of the projections 31, each fusing terminal 42 is concentrically oriented with one end 43 facing outward. And held in a posture parallel to the axial direction of the front insulator 21.
Here, the coils 23, 23,... Are wound around the teeth 26 of the stator core 20 via the projecting portions 28, 38 of the front and rear insulators 21, 22, but here, the coils 23, 23,. It is wound around the teeth 26 adjacent in the direction in order. The windings 23 a, 23 a... Connecting the coils 23, 23 wrap around the outside of the holding unit 30 and are sandwiched between the fusing terminals 42, thereby electrically connecting the fusing terminals 42 to each other. It is connected to the.

  The sensor circuit board 24 includes three rotation detection elements (not shown) that detect the position of the permanent magnet 63 provided on the rotor 19 and output a rotation detection signal, and have an outer diameter that fits inside the holding unit 30. As shown in FIG. 6, four protrusions 46, 46... Having a through hole 47 corresponding to the screw boss 33 of the front insulator 21 are extended on the outer periphery of the doughnut. By allowing the screw boss 33 to penetrate, the protrusion 46 comes into contact with the flange portion 34 and is positioned on the front surface of the front insulator 21. In the center of the lower part of the sensor circuit board 24, a lead-out portion 48 for the signal lines 49, 49,... Of the rotation detecting element is provided, and the heat shrink with adhesive extends over the lead-out portion 48 and the signal line 49. The tube 48a is covered. By using the heat-shrinkable tube 48a, the signal line 49 can be prevented from being disconnected and waterproofed at the same time.

  As shown in FIGS. 8 and 9, each screw boss 33 of the front insulator 21 can be fitted from the rear to the outer periphery of the resin-made insulating portion 50 having the same diameter as the sensor circuit board 24, as shown in FIGS. Four cylindrical bosses 51, 51,. Further, as shown in FIG. 10, the insulating portion 50 is formed by insert-molding three first sheet metal members 52A, second sheet metal members 52B, and third sheet metal members 52C made of sheet metal. The first sheet metal member 52A is bent with a pair of short-circuit pieces 53 and 53 facing left and right outwards at both ends of a lower connecting portion 54A that is curved in a U-shape with the radial direction of the thickness direction. The second sheet metal member 52B is formed and has a pair of short-circuiting pieces 53, 53 on the lower right and upper left of the left connecting portion 54B that is curved in a circular shape with the thickness direction being the front-rear direction. The central portion of the portion 54B is retracted by the bent portions 54d and 54d. The third sheet metal member 52C has a pair of short-circuiting pieces 53, 53 at the lower left and upper right of the right connecting portion 54C that curves in an arc shape, and the bent portion 54d from the lower left short-circuiting piece 53 of the connecting portion 54C. The lateral half-circumferential part of the connecting part 54C is retracted via the bent part, the remaining half-circumferential part is bent vertically inside via the folded part 54e, and the upper right short-circuiting piece 53 is bent outward. It becomes. As shown in FIG. 11, the three sheet metal members 52A to 52C are arranged in a non-contact manner by disposing the second sheet metal member 52B on the left rear side of the first sheet metal member 52A and the third sheet metal member 52C on the right rear side, respectively. In this state, the insulating part 50 is insert-molded in a state of being superimposed on a concentric circle.

Thereby, on the outer periphery of the insulating portion 50, six short-circuit pieces 53, 53,... Corresponding to the respective fusing terminals 42 held by the front insulator 21 and electrically connected diagonally project radially. It is set up. A slit 55 into which the other end 44 of the fusing terminal 42 can be inserted is formed at the tip of each short-circuit piece 53.
Furthermore, a connecting piece 56 located between the second sheet metal member 52B and the lower sheeting piece 53 on the lower side of the third sheet metal member 52C is formed downward in the center of the lower end of the connecting portion 54 of the first sheet metal member 52A. The U-phase, V-phase, and W-phase power lines 57 are spot welded to the rear surfaces of the short-circuit piece 53 and the connection piece 56 on the lower side of the second sheet metal member 52B and the third sheet metal member 52C. On the left and right sides of the connection piece 56, protrusions 56a and 56a are formed for increasing the coupling force with the insulating portion 50. A plurality of upper and lower guide ribs 58, 58,... Are integrally formed in parallel on the rear surface of the lower end of the insulating portion 50 so as to partition the power lines 57 and guide the power lines 57 downward from the sheet metal members 52A to 52C. Is erected. Further, on the rear surface of the insulating portion 50, guide protrusions 50a and 50a are formed on the upper side of the guide rib 58 to guide the left and right power supply lines 57 to the short-circuit piece 53 side, and positioning concave portions 50b and 50b are provided on the inner peripheral side. Is formed. In the lower part of the insulating part 50, a through hole 50c is formed for exposing the connection piece 56 to enhance heat dissipation. A position P shown in FIGS.

When this short-circuit member 25 is overlapped on the sensor circuit board 24 from the front so that the screw boss 33 of the front insulator 21 is inserted into the boss 51 and fixed with screws 88, 88..., The other end 44 of each fusing terminal 42 is Are respectively inserted into the slits 55 of the corresponding short-circuit piece 53. Here, since the sheet metal member is not exposed on the rear surface of the insulating portion 50, the sensor circuit board 24 is brought into contact with the resin. Here, the center hole of the sensor circuit board 24 is smaller than the center hole of the short-circuit member 25.
If the fusing terminal 42 and the short-circuit piece 53 are soldered in this state, the fusing terminals 42 and 42 positioned point-symmetrically are short-circuited by the first to third sheet metal members 52A to 52C, respectively. As shown in FIG. 12, the fusing terminals 42 electrically connected to the windings 23a, 23a,... Between the coils 23, 23,. Thus, the first to third sheet metal members 52A to 52C are electrically connected to form a so-called para-winding delta connection. S is the start of winding and E is the end of winding.

Here, since the fusing terminal 42 and the short-circuit member 25 are separated and the short-circuit piece 53 of the short-circuit member 25 is soldered after the coil 23 is wound, the short-circuit member 25 does not get in the way. .
Further, the fusing terminal 42 is formed with a certain height to perform stable fusing, but here, as shown in FIG. 2 and FIG. 7B, within the height dimension of the fusing terminal 42. Since the sensor circuit board 24 and the short-circuit member 25 are housed in the same, the total length of the brushless motor 17 can be minimized even if the short-circuit member 25 or the like is used. Furthermore, since all members except the signal line and the power supply line are accommodated in the outer diameter of the stator core 20, the outer diameter of the product is not increased and the product becomes compact.

  As shown in FIG. 13, the stator 18 assembled in this way holds the outer periphery of the stator core 20 by support ribs 59, 59... Projecting in the circumferential direction on the inner surfaces of the half housings 6 a and 6 b of the main body housing 6. At the same time, the projections 60, 60 projecting from the inner surface of the half housing 6 a are fitted in the recesses 35, 35 formed on the side surface of the front insulator 21, respectively, so that they are positioned in the axial direction and the circumferential direction. Be contained. When the stator 18 is housed in the half housings 6a and 6b, the stator 18 can be easily assembled in the intended direction by assembling the chamfered portion 41 with the flat surface of the chamfered portion 41 against the support rib 59. The concave portion at the center of each projection 60 is stealed. If this projection 60 is also formed in the half housing 6b, the stator 18 can be held more suitably.

On the other hand, as shown in FIG. 2, the rotor 19 is disposed outside the rotor core 62, the rotating shaft 61 positioned at the shaft center, the cylindrical rotor core 62 disposed around the rotating shaft 61, and the rotor core 62. And a permanent magnet 63 having a cylindrical shape and alternating polarity in the circumferential direction.
The rear end of the rotating shaft 61 is pivotally supported by a bearing 64 held by the cap housing 9, and a centrifugal fan 65 is attached to a front portion thereof. Here, the central portion of the centrifugal fan 65 bulges forward in a mortar shape, and the bearing 64 protrudes rearward. As a result, the distance between the cap housing 9 and the centrifugal fan 65 is reduced, leading to a reduction in the overall length. Reference numeral 66 denotes an intake port (FIG. 1) formed on the left and right side surfaces of the main body housing 6, and 67 denotes an exhaust port (FIGS. 1 and 2) formed on the left and right side surfaces of the cap housing 9.

In FIG. 2, a gear case 68 that accommodates the planetary gear reduction mechanism 72 is provided in front of the brushless motor 17, and the front end of the rotating shaft 61 passes through a cap 69 that closes the rear end of the gear case 68. It is pivotally supported by a bearing 70 held by a cap 69, and a pinion 71 is fixed to the front end.
The planetary gear speed reduction mechanism 72 has a well-known structure in which a plurality of carriers 75 supporting a plurality of planetary gears 74 and 74 revolving in the internal gear 73 are arranged in parallel in the axial direction. 73A) is fixed in the gear case 68 and revolves the second stage planetary gear 74, and the second stage planetary gear 74 and the first stage carrier 75 are simultaneously meshed with each other. The carrier 75 and the planetary gear 74 are provided so as to be able to move back and forth in the axial direction between the carrier 75 and the planetary gear 74 so as to cancel the second-stage deceleration. A speed switching ring 77 is coupled to the internal gear 73A via a pin 76, and a protrusion 78 at the upper end of the speed switching ring 77 is coupled to a speed switching button 80 via front and rear coil springs 79, 79. . Therefore, the internal gear 73A can be moved back and forth via the speed switching ring 77 by sliding the speed switching button 80 back and forth so that the low speed mode at the forward position and the high speed mode at the reverse position can be selected. Become.

  In the driver drill 1 configured as described above, when the trigger 15 is pushed in, the switch is turned on and the brushless motor 17 is driven by the power supply of the battery pack 5. That is, a microcomputer of a controller (not shown) housed in the lower portion of the handle 3 obtains a rotation detection signal indicating the position of the permanent magnet 63 of the rotor 19 output from the rotation detection element of the sensor circuit board 24 and determines the rotation state of the rotor 19. The rotor 19 is rotated by controlling the ON / OFF of each switching element in accordance with the acquired rotation state, and causing current to flow sequentially to each coil 23 of the stator 18. Therefore, the rotation shaft 61 rotates and the rotation decelerated by the planetary gear reduction mechanism 72 is transmitted to the spindle to rotate the chuck 13. By operating the mode switching ring 11, it is possible to select a driver mode in which the clutch mechanism in which the rotation transmission is interrupted with a predetermined torque functions and a drill mode in which the clutch mechanism does not function, and in the driver mode by operating the clutch adjustment ring 12 The torque at which the clutch mechanism operates can be adjusted.

Here, since the coil 23 of the brushless motor 17 is in the para-winding state, the winding resistance is reduced, and a large current can flow. Since this para-winding state can be achieved by using the short-circuit member 25, it can be realized in a small space. That is, as shown in FIG. 2, the short circuit member 25 having a small thickness is assembled inside the holding portion 30 so as not to protrude forward from the tip of the protrusion 31 of the holding portion 30. The short-circuit member 25 can be installed using the front space effectively, and the compactness can be maintained.
Moreover, since the six coils 23 are wound with a single winding (so-called one-stroke writing), all the coils 23 can be wound in one step, and no connecting wire connecting between the diagonal coils is required. It becomes. The lack of crossovers also leads to compactness.
Furthermore, since the sensor circuit board 24 is provided on one end side of the brush race motor 17 and power is supplied to the coil 23 from the same side, a large current can be supplied while maintaining compactness. In particular, since the sensor circuit board 24 and the short-circuit member 25 are arranged in this order on the one end side of the stator 18, the sensitivity of the sensor is good.

  In the above embodiment, the brushless motor 17 is accommodated in the main body housing 6 formed by the half housings 6a and 6b. As shown in FIGS. 14 to 16, the four first cutouts of the front insulator 21 of the stator 18 are arranged at the bottom of the cylindrical housing 81 with the stator 18 of the brushless motor 17 facing rearward so that the short-circuit member 25 side is rearward. The tips are fitted to the four L-shaped receiving ribs 82, 82,... Which are in contact with the end surfaces of the stator core 20 and the second notches 37 of the front insulator 21, respectively. And a plate-like detent rib 83 that abuts against the end surface of the stator core 20, and a pair of vertical ribs 84, 84 that abut against the peripheral surface of the stator 18 are provided on the front side And it is provided symmetrically. 81a is a housing recess of the bearing. Thus, the stator 18 can be suitably assembled by providing the cylindrical housing 81 with the engaging portion with the insulator and the stator.

Further, screw bosses 85, 85 having a height flush with the end face of the accommodated stator core 20 are provided between the left and right vertical ribs 84, 84. By screwing 86, the washer 87 is fitted into the lateral notch 40 of the rear insulator 22 so that the end face of the stator core 20 can be pressed from the front.
Therefore, the movement of the stator 18 here is restricted by the receiving rib 82, the movement in the circumferential direction is restricted by the anti-rotation rib 83, and the vertical rib 84 is centered in the cylindrical housing 81. The The forward movement is restricted by the screw 86 and the washer 87. Since the front insulator 21 is provided with a guide portion 21a, when the stator 18 is press-fitted, the guide portion 21a is fitted between the vertical ribs 84 and 84 as shown in FIG. If you press it in, you can set it smoothly at the target position. After press-fitting, it will also be positioned in the circumferential direction.
As described above, even in the case of the cylindrical housing 81, the stator 18 can be easily positioned using the notches 36, 37, and 40 provided in the front and rear insulators 21 and 22, and the front and rear insulators 21 and 22 can be made common. Become.

  On the other hand, in the above embodiment, the signal line 49 of the sensor circuit board 24 is drawn from the same side (lower side) as the power supply line 57 of the short-circuit member 25. However, like the stator 18 shown in FIG. The signal line 49 may be drawn from the upper side by changing the phase of the substrate 24 by 180 °. In this way, even when the motor housing 91 in which the brushless motor 17 is accommodated is also used as a grip, as in the grinder 90 shown in FIG. 18, for example, the protrusion of the motor housing 91 on the power line 57 side is suppressed. Thus, the motor housing 91 at this portion can be made thinner. In addition, wiring is easy even with other structures, and the insulator can be shared. In FIG. 18, 92 is a controller, 93 is a switch connected to the controller 92 by a lead wire 94, 95 is a slide button for turning the switch 93 ON / OFF via a linkage bar 96, and 97 protrudes the spindle 98 downward. It is a front housing.

  Further, the sensor circuit board 24 can be provided on the side opposite to the short-circuit member 25. That is, the sensor circuit board 24 is provided on the rear surface of the rear insulator 22 as in the stator 18 </ b> A shown in FIGS. 19 to 21. Here, the lateral notch 40 provided on the rear insulator 22 on the outer periphery of the sensor circuit board 24. And the horizontal notch 22a and the chamfered part 22b are formed according to the chamfered part 41, and the assembly | attachment to a cylindrical housing is also possible. Reference numeral 99 denotes a screw, and reference numeral 100 denotes a rotation detection element (Hall IC). In this case, the rotation detection element 100 detects the position of the permanent magnet provided in the centrifugal fan 65. Therefore, here, the short-circuit member 25 is assembled to the front insulator 21 without passing through the sensor circuit board 24, but the short-circuit member 25 fits the recess on the back side of the boss 51 to the upper surface of the screw boss 33 of the front insulator 21. Therefore, even if there is no sensor circuit board 24, the position of the short-circuit member 25 does not change. The short-circuit member 25 is positioned by fitting the unevenness between the screw boss 33 and the boss 51. In FIG. 19, 22c, 22c,... Are projections integrally projecting to the rear surface of the rear insulator 22, and are inserted into through holes provided in the sensor circuit board 24 to thermally deform the sensor circuit board 24. Prevent it from coming off.

On the other hand, the structure of the insulator can be changed as appropriate. FIG. 22 shows a modification example of the front insulator, and FIG. 23 shows a modification example of the rear insulator. First, in the front insulator 21, the front side of the base of each projection 28 is recessed in the direction orthogonal to the projection 28. A groove 28a is formed, and relief portions 28b and 28b that are concave in the radial direction are formed on both sides in the circumferential direction of the base of each protrusion 28, respectively. Similarly, in the rear insulator 22, a concave groove 38 a is formed on the rear surface side of the base of each protrusion 38 in a direction orthogonal to the protrusion 38, and on both sides in the circumferential direction of the base of each protrusion 38, Relief portions 38b and 38b that are concave in the radial direction are formed.
The concave grooves 28a, 38a are for receiving one winding start of the coil 23 in each of the teeth 26. When the first one is just received and wound, the second and subsequent grooves are aligned accordingly. Will be rolled up. Further, the relief portions 28b and 38b are provided so that a nozzle for winding the coil 23 can easily pass therethrough, so that the coil 23 can be smoothly wound around both sides of the protrusion 38 on the inner peripheral surface of the rear insulator 22. Are formed in the recesses 38c, 38c.
Here, since the horizontal notches 40 and 40 are located between the protrusions 38 and 38 and the protrusion 38 is located at the two-surface width portion of the chamfers 41 and 41, the outer periphery of the rear insulator 22 is Hard to get bigger.

And although the short-circuit means is composed of the short-circuit member and the fusing terminal in the above embodiment, the fusing terminal is omitted and the windings are short-circuited only by the short-circuit member, or conversely, the short-circuit member is omitted. It is also possible to connect the fusing terminals with lead wires.
In addition, the power tool is not limited to a type that drives a tip tool such as a driver drill, a saw and a grinder, and the present invention can also be applied to a cleaner and a garden tool such as a blower. Also, the present invention can be applied to an electric tool using a sensorless brushless motor without a sensor circuit board.

  DESCRIPTION OF SYMBOLS 1 ... Driver drill, 2 ... Main body, 6 ... Main body housing, 17 ... Brushless motor, 18 ... Stator, 19 ... Rotor, 20 ... Stator core, 21 ... Front insulator, 22 ... Rear insulator, 23 .. Coil, 23 a .. Winding, 24 .. Sensor circuit board, 25 .. Short circuit member, 30 .. Holding part, 31 .. Projection, 35 .. Recess, 36 .. First cutout part, 37. · Second cutout portion, 40 · · Horizontal cutout portion, 42 · · Fusing terminal, 49 · · Signal line, 50 · · Insulation portion, 52A · · First sheet metal member, 52B · · Second sheet metal member, 52C ·・ Third sheet metal member, 53 ..Short-circuiting piece 54 ..Connecting portion 57 ..Power line 61 ..Rotating shaft 81 ..Cylinder housing 82 ..Receiving rib 83. 84 ・ ・ Vertical ribs, 90 ・ ・ Grinder.

Claims (9)

A stator core;
A first insulator disposed on one end side of the stator core;
A second insulator disposed on the other end side of the stator core;
A coil wound around the first insulator and the second insulator;
A first fusing terminal and a second fusing terminal, which are fixed to the first insulator and to which the coil winding is connected;
A stator having a short-circuit member fixed to the first insulator and short-circuiting the first fusing terminal and the second fusing terminal;
With permanent magnets,
A rotor having a rotating shaft to which the permanent magnet is fixed, and a brushless motor comprising:
A power tool comprising: a tip tool holding portion driven by the rotor.   The power tool according to claim 1, wherein the short-circuit member is fixed to the first insulator by a screw.   The power tool according to claim 1, wherein a power line is connected to the short-circuit member.   The electric tool according to any one of claims 1 to 3, further comprising a fan fixed to the rotating shaft on the second insulator side.   5. The electric tool according to claim 1, wherein the first fusing terminal and the second fusing terminal are soldered to the short-circuit member.   The power tool according to claim 1, wherein a slit into which the first fusing terminal and the second fusing terminal are inserted is formed in the short-circuit member. A stator core;
A first insulator disposed on one end side of the stator core;
A second insulator disposed on the other end side of the stator core;
A coil wound around the first insulator and the second insulator;
Six first to sixth fusing terminals fixed to the first insulator and connected to the winding of the coil;
A short-circuit member connected to the first to sixth fusing terminals;
A stator having four first to fourth screws for fixing the short-circuit member to the first insulator;
With permanent magnets,
A rotor having a rotating shaft to which the permanent magnet is fixed, and a brushless motor comprising:
A power tool comprising: a tip tool holding portion driven by the rotor. The first fusing terminal is disposed between the first screw and the second screw;
The second fusing terminal and the third fusing terminal are disposed between the second screw and the third screw,
The fourth fusing terminal is disposed between the third screw and the fourth screw;
The power tool according to claim 7, wherein the fifth fusing terminal and the sixth fusing terminal are disposed between the fourth screw and the first screw. A stator core;
A first insulator disposed on one end side of the stator core;
A second insulator disposed on the other end side of the stator core;
A coil wound around the first insulator and the second insulator;
An electric power tool comprising a brushless motor having a rotation detecting element arranged on the first insulator side and the coil being short-circuited on the second insulator side.

Images