JP5138491B2 - Stator and brushless motor - Google Patents

Description

  The present invention relates to a stator in which connecting ends of a plurality of coils are connected to a terminal, and a brushless motor including the stator.

  2. Description of the Related Art Conventionally, there are stators that constitute a brushless motor in which a coil is wound by concentrated winding on a plurality of radially extending tooth portions provided on a stator core. In such a stator, connection end portions that are ends of winding start and winding end of a plurality of coils are connected to a metal terminal for supplying power to each coil.

  For example, the terminal described in Patent Document 1 is fixed to a holder made of an insulating resin material that is fixed to one end portion in the axial direction of the stator. And this terminal consists of a strip | belt-shaped metal plate material which has electroconductivity, and has a connection part which folds up the one end part of the longitudinal direction of this metal plate material in U shape. The connection end portion of the coil is disposed in the connection portion, and is connected to the terminal by being joined to the connection portion by fusion welding such as Tig welding.

  By the way, tension may be applied to the connection end of the coil. And when the diameter of the conducting wire which comprises a coil is thick, tension | tensile_strength acts on a connection end part easily. For this reason, it may be difficult to arrange the connection end portion in the connection portion, or the connection end portion may not be properly accommodated in the connection portion. In addition, when the connection portion is caulked so as to close the opening of the connection portion before welding the connection portion and the connection end portion, if the connection end portion moves within the connection portion due to the action of tension or the like, Some parts may not be caulked well. From these, defective welding is likely to occur, and in order to reduce this defective welding, after performing the process of automatically placing the connection end in the connection portion by a device that places the connection end in the connection portion, The process which adjusts the arrangement position of a connection end part was performed. However, when the process of adjusting the arrangement position of the connection end portion is performed manually, poor welding between the connection portion and the connection end portion is reduced, but the number of steps is increased.

Therefore, the terminal of Patent Document 1 is provided with a restricting portion that protrudes toward the inside of the connection portion in the terminal of Patent Document 1 so that the connection end portion of the coil easily stays in the connection portion. The restricting portion is formed closer to the opening of the connecting portion than the connecting end portion of the coil disposed in the connecting portion to be connected to the terminal. By this restricting portion, the movement of the connecting end portion arranged in the connecting portion to the opening side of the connecting portion is restricted.
JP 2005-328654 A

  However, if the amount of protrusion of the restricting portion to the inside of the connecting portion is small, the effect of holding the connecting end portion in the connecting portion is reduced, so the connecting end portion gets over the restricting portion due to thermal shock during welding, etc. You may end up outside. On the other hand, if the protruding amount of the restricting portion to the inside of the connection portion is large, it becomes difficult to insert the connection end portion into the connection portion from the opening portion of the connection portion. Also, if the opening of the connection part is opened due to thermal shock during welding, the effect of restricting the connection end by the restricting part will diminish, so the connection end will go out of the connection part and weld. There is a risk of defects.

  The present invention has been made in view of such circumstances, and the purpose thereof is to allow the connection end of the coil to be easily disposed in the connection portion of the terminal, and the connection end portion to be stably in the connection portion. An object of the present invention is to provide a stator to be held and a brushless motor including the stator.

  In order to solve the above-mentioned problem, the invention described in claim 1 includes a substantially cylindrical stator core having a plurality of radially extending teeth portions, and a plurality of coils wound around each of the teeth portions by concentrated winding. A stator made of an insulating resin material holding a plurality of terminals having connection portions to which the connection end portions of the coils are connected, wherein the terminal is connected to the connection end from the radially outer side. The holder includes a coil insertion portion formed at a position aligned with the connection portion in the axial direction, penetrating in the axial direction and opening radially outward, and a periphery of the coil insertion portion. A first coil insertion gap having a circumferential width larger than the outer diameter of the connection end portion between the coil insertion portion and the inner circumferential surface of the coil insertion portion when viewed from the axial direction on one side of the direction. 1 coil holder, A second coil insertion gap having a width in the circumferential direction larger than the outer diameter of the connection end portion is provided between the coil insertion portion and the inner circumferential surface of the coil insertion portion when viewed from the axial direction on the other circumferential side of the coil insertion portion. A second coil holding portion formed as described above, and the connection end portion is disposed radially inside the first coil holding portion and the second coil holding portion in the coil insertion portion, and is axially The gist is that the first coil holding part and the second coil holding part are opposed to each other in the radial direction at two positions shifted to each other.

  According to this configuration, the first coil insertion gap and the second coil insertion gap are both formed so that the circumferential width is larger than the outer diameter of the connection end. It can be easily inserted into the coil insertion portion from the opening through the first coil insertion gap and the second coil insertion gap. And since it is not necessary to make a connection part complicated shape, such as providing the structure for hold | maintaining a connection end part in a connection part, a connection end part can be easily arrange | positioned in a connection part. Further, the connecting end portion is disposed radially inward of the first coil holding portion and the second coil holding portion in the coil insertion portion, and the first coil holding portion and the second coil holding portion at two positions shifted in the axial direction. And facing in the radial direction. For this reason, when a force that moves the connecting end radially outward is applied to the connecting end, the connecting end contacts the first coil holding portion and the second coil holding portion to insert the coil. It is suppressed from going out of the section. Therefore, the connection end is held in the coil insertion portion by the first coil holding portion and the second coil holding portion. As a result, the connection end portion is stably held in the connection portion of the terminal arranged in the axial direction with the coil insertion portion.

  According to a second aspect of the present invention, in the stator according to the first aspect, the connection end portion includes an axial end surface on the holder side of the stator core, and the coil insertion portion into which the connection end portion is inserted. The end portion on the stator core side of the holder is inclined according to the inclination of the connection end portion, and the connection end portion is guided to the coil insertion portion. The gist is that a guide slope is formed.

According to this configuration, by arranging the inclined part of the connection end along the guide slope provided on the holder, the arrangement of the connection end can be made more stable.
According to a third aspect of the present invention, in the stator according to the first or second aspect, the first coil holding portion and the second coil holding portion have a radially outer corner portion having an arc shape. That is the gist.

  According to this configuration, since the connection end is inserted into the coil insertion portion from the radially outer opening, the radially outer corners of the first coil holding portion and the second coil holding portion are formed in an arc shape. If it is made, a connection end part can be easily inserted in a coil insertion part along the circular-arc-shaped corner | angular part of a 1st coil holding part and a 2nd coil holding part. Moreover, when the connection end is inserted into the coil insertion portion, the connection end is prevented from being damaged by the first coil holding portion and the second coil holding portion.

  According to a fourth aspect of the present invention, in the stator according to any one of the first to third aspects, when the holder is viewed from the axial direction, the first coil holding portion and the second coil holding portion are The gist is that the gap between is smaller than the outer diameter of the connection end.

According to this configuration, it is further suppressed that the connection end portion goes out of the coil insertion portion through between the first coil holding portion and the second coil holding portion.
According to a fifth aspect of the present invention, there is provided a cylindrical housing with a bottom, a stator according to any one of the first to fourth aspects fixed to an inner peripheral surface of the housing, and an inner side of the stator. The gist of the invention is that the rotor is disposed and rotated relative to the stator by energizing the coil.

  According to this configuration, the connection end portion is stably held in the coil insertion portion by the first coil holding portion and the second coil holding portion, so that the connection end portion is stably in the connection portion aligned in the axial direction with the coil insertion portion. Held. Therefore, welding failure is reduced by connecting the connection end portion and the connection portion in a state where the connection end portion is stably held in the connection portion. As a result, defective products can be reduced.

  According to the present invention, a connection end portion of a coil can be easily disposed in a connection portion of a terminal, and a stator in which the connection end portion is stably held in the connection portion, and a brushless motor including the stator are provided. Can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
A brushless motor 1 shown in FIGS. 1A and 1B is used as a drive source of a power steering device that assists the operation of a vehicle steering shaft connected to a steering wheel of a vehicle (not shown). As shown in FIGS. 1 (a) and 1 (b), a substantially cylindrical stator 3 is fixed to the inner peripheral surface of the bottomed cylindrical housing 2, and inside the stator 3, The rotor 4 is rotatably arranged. The rotor 4 is connected to the vehicle steering shaft (not shown). A holder 5 made of an insulating synthetic resin material is fixed to an end of the housing 3 on the opening side of the stator 3, and the holder 5 covers one end of the stator 3 in the axial direction. .

  As shown in FIG. 2A, the stator core 6 constituting the stator 3 has a plurality of tooth portions 7 (this embodiment) extending radially toward the center at predetermined angles (30 ° in FIG. 2A). Then, 12 end portions on the outer peripheral side are connected in the circumferential direction by the connecting member 8 to form a substantially cylindrical shape. A bobbin 9 made of an insulating resin material that covers both end surfaces in the axial direction and both side surfaces in the circumferential direction of each tooth portion 7 is attached to each tooth portion 7 from both sides in the axial direction. The coils 11 are wound by winding the conducting wire 10 a plurality of times by concentrated winding from above. The conducting wire 10 has a configuration in which a metal wire 10a made of a conductive metal material (copper in this embodiment) is covered with a covering member 10b made of an insulating resin material. Each coil 11 has a U-phase coil 12, a V-phase coil 13, and a W-phase coil in accordance with three-phase (U-phase, V-phase, and W-phase) exciting currents as drive power supplied to the brushless motor 1. 14

  The U-phase coil 12, the V-phase coil 13, and the W-phase coil 14 are each wound around a predetermined tooth portion 7 and are spaced apart (not adjacent) in the circumferential direction across the coils of other phases. It is wound continuously. In the present embodiment, the U-phase coil 12, the V-phase coil 13, and the W-phase coil 14 are wound around two predetermined adjacent tooth portions 7 and straddle the tooth portions 7 corresponding to other phases. It is wound around two adjacent tooth portions 7 on the opposite sides of 180 °.

  Specifically, the U-phase coil 12 is wound around the tooth portion 7 from the start end portion 12s to the end portion 12e. 2b between the terminal portions 12e of the two U-phase coils 12 arranged on the upper side in the drawing and the start ends 12s of the two U-phase coils 12 arranged on the lower side in the drawing. ), The crossover line 12w is passed.

  Note that the start end 12s of the upper U-phase coil 12 in the drawing is drawn from the drawing position 12X indicated by the dotted line in the drawing, and the terminal end 12e of the lower U-phase coil 12 in the drawing is indicated by the dotted line in the drawing. It is pulled out from the pulling position 12Y.

  That is, the conducting wire 10 drawn from the drawing position 12X is wound as the U-phase coil 12 from the start end portion 12s to the end end portion 12e on the two teeth portions 7 arranged on the upper side in the drawing. And the connecting wire 12w is passed by the conducting wire 10 from each termination | terminus part 12e to the two teeth part 7 arrange | positioned in the lower side in the figure, and the conducting wire 10 is wound as a U-phase coil from the starting end part 12s to each teeth part 7. Be dressed. Furthermore, the starting end portion 12s of each U-phase coil 12 is pulled out radially outward of the stator core 6 from the pulling position 12Y.

  Similarly, the conducting wire 10 drawn from the drawing position 13X is wound around the two tooth portions 7 as a V-phase coil 13 from the start end portion 13s to the end end portion 13e. And the connecting wire 13w is passed by the conducting wire 10 from each starting end part 13s to the two teeth part 7 arrange | positioned in the position which opposes, and conducting wire 10 is each V-phase coil 13 from the starting end part 13s to each teeth part 7. Wrapped as Furthermore, the terminal portion 13e of each V-phase coil 13 is drawn out to the radially outer side of the stator core 6 from the drawing position 13Y.

  Similarly, the conducting wire 10 drawn from the drawing position 14X is wound around the two tooth portions 7 as a W-phase coil from the start end portion 14s to the end portion 14e. And the connecting wire 14w is passed by the conducting wire 10 from each termination | terminus part 14e to the two teeth part 7 arrange | positioned in the position which opposes, and the conducting wire 10 is W-phase coil 14 from each starting part 14s to each teeth part 7. Wrapped as Further, the end portion 14e of each W-phase coil 14 is drawn out to the outside in the radial direction of the stator core 6 from the drawing position 14Y.

  The start end portions 12s to 14s, the end portions 12e to 14e, and the crossover wires 12w to 14w are arranged on one side in the axial direction of the stator 3 (left side in FIG. 2B). Note that a total of twelve start end portions 12s to 14s and end portions 12e to 14e drawn out from the pull-in positions 12X to 14X and the pull-out positions 12Y to 14Y radially outward of the stator core 6 In addition, the covering member 10b is removed and the metal wire 10a is exposed at the front end portion of each connecting end 11a. The 12 start end portions 12s to 14s and the end end portions 12e to 14e (that is, the connection end portion 11a) are pulled out to the surface of the holder 5 opposite to the stator 3 (FIGS. 1A and 1B). Reference) and a plurality of (four in this embodiment) terminals 15 arranged on the surface of the holder 5 opposite to the stator 3 are respectively connected. Moreover, each crossover line 12w-14w is arrange | positioned in the accommodation recessed part 24 formed in the holder 5 mentioned later.

  As shown in FIG. 2A, the rotating shaft 16 constituting the rotor 4 is pivotally supported by a bearing (not shown) provided in the housing 2. A cylindrical rotor core 18 is fixed to the rotary shaft 16, and a magnet magnetized on the outer peripheral surface of the rotor core 18 with different polarities (N pole, S pole) at predetermined angles in the circumferential direction. 19 is fixed.

  In the brushless motor 1 configured as described above, U-phase, V-phase, and W-phase excitation currents each having a phase difference of 120 ° from an excitation circuit (not shown) are respectively supplied to the U-phase coil 12, the V-phase coil 13, and the W-phase. It is supplied to the coil 14. Then, the U-phase coil 12, the V-phase coil 13, and the W-phase coil 14 are respectively excited to generate a rotating magnetic field in the stator 3, and the rotor 4 rotates according to the rotating magnetic field.

  As shown in FIGS. 1 (a) and 1 (b), the substantially annular holder body 21 constituting the holder 5 has an outer diameter substantially equal to the outer diameter of the stator core 6, and its inner diameter. Is formed substantially equal to the inner diameter of the stator core 6. As shown in FIGS. 3A and 3B, the mounting surface 22 of the holder body 21 on the stator core 6 side is along the axial direction at a plurality of locations (three locations in the present embodiment) on the outer peripheral edge. An engaging piece 23 extending in a protruding manner is formed. Further, on the outer peripheral surface of the stator 3 described above (see FIG. 1B), engaging portions (not shown) are formed at positions corresponding to the engaging pieces 23, and the holder 5 extends along the axial direction. Then, when it is moved to the stator 3 side, the engaging piece 23 is snap-fit engaged with the engaging portion, and the holder 5 is fixed to the stator 3. In the state where the holder 5 is fixed to the stator 3, the holder main body 21 and the stator core 6 are coaxial (the central axes coincide).

  Further, the mounting surface 22 of the holder main body 21 is provided with a substantially arc-shaped accommodation recess 24 extending in the circumferential direction. In the accommodation recess 24, as described above, each of the crossover wires 12w, 13w, 14w (see FIG. 2B) is accommodated. The accommodation recess 24 is formed at an appropriate location to accommodate the crossover wires 12w, 13w, and 14w, respectively.

  Further, as shown in FIGS. 4A and 4B, the coil insertion portion 25 is provided at six locations in the circumferential direction of the holder main body portion 21 from the outer peripheral edge of the holder main body portion 21 toward the radial inner side. Is recessed. Each coil insertion portion 25 is formed so as to penetrate in the axial direction of the stator 3 (perpendicular to the paper surface in FIG. 4A) and to open radially outward. In addition, the six coil insertion portions 25 are respectively formed at positions near the drawing positions 12X, 13X, and 14X and the drawing positions 12Y, 13Y, and 14Y when the holder 5 is fixed to the stator 3 (see FIG. 2 (a)). Further, the width (circumferential width) of each coil insertion portion 25 is set to a value slightly larger than the diameter of the conducting wire 10 (see FIG. 2A) constituting the coil 11. The width in the circumferential direction of each coil insertion portion 25 is about 1.3 times the diameter of the conducting wire 10. Then, two connection end portions 11a are inserted into each of the coil insertion portions 25 from the radially outer opening (see FIG. 2A). In the present embodiment, when the holder 5 is fixed to the stator 3, each coil insertion portion 25 is connected to the base end portion of the connection end portion 11 a to be inserted (that is, the connection end portion drawn from the stator 3). 11a, which is a position slightly shifted in the circumferential direction with respect to the connection end portion 11a in the vicinity of the end surface in the axial direction on the holder 5 side of the stator core 6 (see FIG. 8).

  On both sides in the circumferential direction of each coil insertion portion 25, two coil holding portions for holding the connection end portion 11a of the coil 11 inserted in the coil insertion portion 25 in the coil insertion portion 25, that is, a first A coil holding part 26 and a second coil holding part 27 are provided.

  As shown in FIG. 5A and FIG. 5B, the first coil holding portion 26 is a connection end portion that is inserted into the coil insertion portion 25 in the opening portion on the radially outer side of the coil insertion portion 25. It is provided on one side in the circumferential direction closer to the base end of 11a. Incidentally, the two connection end portions 11 a inserted into the two coil insertion portions 25 on the lower side and the upper side in FIG. 5A each have a base end portion in the circumferential direction of each coil insertion portion 25. Since they are on both sides, the first coil holding portions 26 are provided on both sides in the circumferential direction in the radially outer openings of these two coil insertion portions 25.

  Each first coil holding portion 26 has a triangular prism shape extending in the axial direction from the installation surface 28 on the side where the terminal 15 is arranged in the holder main body portion 21 toward the mounting surface 22 on the stator core 6 side. The axial length is formed slightly shorter than the axial length of the holder body 21 (see FIG. 6). And each 1st coil holding | maintenance part 26 makes the shape seen from the axial direction the substantially right triangle shape which the width of the circumferential direction becomes wide as it goes to radial direction outer side, and in each 1st coil holding | maintenance part 26, The radially outer side surface is formed flush with the outer peripheral surface of the holder main body 21. Further, the side surface on the coil insertion portion 25 side in the vicinity of each first coil holding portion 26 is formed flush with the inner peripheral surface of the coil insertion portion 25, extends along the radial direction, and is parallel to the axial direction. Yes. Further, in each first coil holding portion 26, the side surface on the coil insertion portion 25 side and the side surface on the outer side in the radial direction form a substantially right angle, and a corner portion formed by these two side surfaces, that is, each first coil holding portion. A corner portion on the coil insertion portion 25 side in the portion 26 on the radially outer side has an arc shape (R shape) in which the shape seen from the axial direction swells in the circumferential direction.

  Further, each first coil holding portion 26 is between the outer diameter D of the connecting end portion 11 a (that is, the outer diameter of the conducting wire 10 constituting the coil 11) between the first coil holding portion 26 and the inner peripheral surface of the coil insertion portion 25 when viewed from the axial direction. Also, the first coil insertion gap 29 having a large circumferential width is formed. In the present embodiment, the circumferential width W <b> 1 of the first coil insertion gap 29 is equal to the circumferential width of the coil insertion portion 25.

  The second coil holding portion 27 is on the other side in the circumferential direction of each coil insertion portion 25, that is, on the opposite side to the side where the first coil holding portion 26 is provided on both sides in the circumferential direction of each coil insertion portion 25. Is provided. In the two coil insertion portions 25 on the lower side and the upper side in FIG. 5A, the first coil holding portions 26 are provided on both sides in the circumferential direction of the radially outer opening. The two-coil holding portion 27 has a connection end portion 11a arranged on the radially outer side of the two connection end portions 11a inserted into the coil insertion portion 25 among both sides in the circumferential direction of the coil insertion portion 25. It is provided on the side opposite to the side where the first coil holding portion 26 closer to the base end portion is provided.

  As shown in FIGS. 4A and 4B, each of the second coil holding portions 27 can be provided with two connection end portions 11 a from the radially inner end (bottom portion) of the coil insertion portion 25. The first coil holding portion 26 is formed radially inwardly at a position spaced apart from the first coil holding portion 26. And each 2nd coil holding | maintenance part 27 makes the substantially square pillar shape extended along an axial direction, and the one part is the circumferential direction toward the inner side of the coil insertion part 25 from the inner peripheral surface of the coil insertion part 25. It protrudes. In addition, each second coil holding portion 27 is between the inner peripheral surface of the coil insertion portion 25 and the second coil insertion gap 30 having a larger circumferential width than the outer diameter D of the connection end portion 11a when viewed from the axial direction. Is provided. In the present embodiment, the circumferential width W2 of the second coil insertion gap 30 is 5 to 10% greater than the outer diameter D of the connection end 11a. Further, as shown in FIG. 6, each of the second coil holding portions 27 is formed such that the axial end surface on the installation surface 28 side is flush with the installation surface 28, and the mounting surface 22 side (that is, the stator 3 side). The end surface in the axial direction of the first coil holding portion 26 is formed so as to be closer to the installation surface 28 than the end surface on the mounting surface 22 side. Further, as shown in FIGS. 4A and 4B, the corners on the coil insertion portion 25 side and the radially outer side of each second coil holding portion 27 are in the circumferential direction when viewed from the axial direction. An arcuate shape (R shape) is formed.

  Further, as shown in FIGS. 5A and 6, on the mounting surface 22 side of the holder main body portion 21, the first coil holding portion 26 and the second coil on both sides in the circumferential direction of each coil insertion portion 25. A guide slope 31 is formed at a portion on the inner peripheral side of the holding portion 27. The guide slope 31 is formed so as to follow the inclination of the connection end portion 11a toward the corresponding coil insertion portion 25 from the end portion on the holder 5 side in the stator 3, and the closer to the coil insertion portion 25 along the circumferential direction. It inclines so that the distance between the installation surfaces 28 may become short.

  Each coil insertion portion 25 accommodates two connection end portions 11a of the U-phase coil 12, the V-phase coil 13, and the W-phase coil 14, respectively. That is, as shown in FIG. 7, each connection end portion 11 a is guided from the position slightly shifted in the circumferential direction from the inserted coil insertion portion 25 to the opening portion on the radially outer side of the coil insertion portion 25. The coil insertion portion 25 is inserted into the coil insertion portion 25 from the radially outer opening through the first coil insertion gap 29 and the second coil insertion gap 30. At this time, the circumferential width W1 of the first coil insertion gap 29 and the circumferential width W2 of the second coil insertion gap 30 (see FIG. 4B) are both larger than the outer diameter D of the connection end portion 11a. Since it is formed large, the connection end portion 11 a is easily inserted into the coil insertion portion 25 through the first coil insertion gap 29 and the second coil insertion gap 30. And since the coil insertion part 25 in which this connection end part 11a is inserted with respect to the base end part of the connection end part 11a is arrange | positioned in the position shifted | deviated to the circumferential direction, as shown in FIG. The connection end portion 11 a inserted into is in a state inclined with respect to the axial direction between the end surface on the holder 5 side of the stator 3 and the installation surface 28 of the holder 5. That is, the connection end portion 11 a inserted into the coil insertion portion 25 is inclined in the axial direction from the first coil holding portion 26 to the second coil holding portion 27 when viewed from the radial direction. Further, the base end portion of each connection end portion 11a is in the vicinity of the base end portion of the tooth portion 7, and the coil insertion portion 25 is recessed from the outer peripheral edge of the holder main body portion 21 toward the radially inner side. Each connection end portion 11a is arranged so as to be directed toward the inner peripheral side as approaching the coil insertion portion 25 to be inserted. Therefore, of the two connection end portions 11a accommodated in each coil insertion portion 25, the connection end portion 11a disposed on the outer peripheral side is in the radial direction with the first coil holding portion 26 in the vicinity of the mounting surface 22 on the stator 3 side. In the vicinity of the installation surface 28, the second coil holding portion 27 provided radially inward of the first coil holding portion 26 is opposed in the radial direction. Accordingly, of the two connection end portions 11a accommodated in each coil insertion portion 25, the connection end portion 11a arranged on the outer peripheral side is surrounded by the first coil holding portion 26 in the vicinity of the mounting surface 22 on the stator 3 side. The movement toward the outer side is restricted by the second coil holding portion 27 in the vicinity of the installation surface 28. That is, of the two connection end portions 11 a accommodated in each coil insertion portion 25, the connection end portion 11 a arranged on the outer peripheral side is displaced in the axial direction by the first coil holding portion 26 and the second coil holding portion 27. Further, the movement outward in the radial direction is restricted at two locations and is held in the coil insertion portion 25. And the connection end part 11a arrange | positioned at the inner peripheral side among the two connection end parts 11a accommodated in each coil insertion part 25 is moved to the outer peripheral side by the connection end part 11a arranged at the outer peripheral side. It is regulated and held in the coil insertion portion 25.

  As shown in FIG. 9, the connection end portion 11 a drawn from one end portion in the axial direction of the stator 3 is inclined between the axial end surface on the holder 5 side in the stator core 6 and the coil insertion portion 25. The site | part is arrange | positioned so that the guide slope 31 may be followed. As described above, the connection end portion 11a is arranged along the guide slope 31 so that it is guided to the coil insertion portion 25 by the guide slope 31 and the distal end portion of the connection end portion 11a is inserted into the coil. A more stable posture can be maintained in the portion 25.

  As shown in FIG. 3A, each terminal 15 arranged on the installation surface 28 of the holder 5 is formed by bending a plurality of portions of a conductive metal plate material. Of the four terminals 15, the three terminals 15 a to 15 c arranged on the upper side in the drawing each have a belt-like terminal body 41. And the terminal main-body part 41 of each terminal 15a-15c is formed with the connector part 42 which can supply the electric power from the outside in the upper end part in FIG. (A) A connecting portion 43 is formed so as to be aligned with the three upper coil insertion portions 25 in the axial direction. Further, the belt-like terminal main body 41 of the terminal 15d arranged on the lower side in the figure has the terminal main body 41 of the terminal main body 41 aligned with the three coil insertion portions 25 on the lower side in FIG. The connection part 43 is integrally formed in three places, both ends and a substantially central part.

  The connection part 43 is for connecting the connection end part 11a of the coil 11 (that is, the U-phase coil 12, the V-phase coil 13 and the W-phase coil 14) wound around the stator 3 of the brushless motor 1 (FIG. 2 (a) and FIG. 2 (b)). Each connection portion 43 has a shape along the coil insertion portion 25 formed in the holder main body portion 21, and faces outward in the radial direction when the terminal 15 is set on the installation surface 28 of the holder main body portion 21. It is formed to open.

  As shown in FIG. 10A and FIG. 10B, each connecting portion 43 removes the end portion in the longitudinal direction of the terminal body portion 41 (or a portion other than the end portion in the longitudinal direction) by the covering member 10b. The connection end portion 11a is folded in a U shape so as to sandwich the connection end portion 11a. And since the terminal main-body part 41 was folded in this way, each connection part 43 has a pair of coil connection parts 43a and 43b which mutually oppose. The pair of coil connection portions 43 a and 43 b in each connection portion 43 are parallel to each other, and the width between the coil connection portions 43 a and 43 b is substantially equal to the outer diameter of the conducting wire 10.

  As shown in FIG. 3B, the terminal 15a has a fixed piece 44 extending so as to protrude toward the holder 5, and the holder main body 21 corresponds to the fixed piece 44 of the terminal 15a. A fixing hole 32 is formed at a position where the fixing is performed. The terminal 15 a is fixed to the holder 5 by the fixing piece 44 being fitted into the fixing hole 32. Similarly, the terminals 15b to 15d are also extended with a fixing piece 44 (not shown) protruding toward the holder 5, and are fixed to the holder main body 21 at positions corresponding to the fixing pieces 44 of the terminals 15b to 15d. Holes 32 (see FIG. 4A) are formed respectively. The terminals 15b to 15d are fixed to the holder 5 by inserting the fixing pieces 44 into the corresponding fixing holes 32, respectively. Moreover, in the holder main-body part 21, the some support wall 33 which supports the terminal main-body part 41 of the terminals 15a-15c from the both sides of a plate | board thickness direction is provided in the vicinity of the terminals 15a-15c.

  As described above, in a state where the terminals 15a to 15d are fixed to the holder 5, the connection portions 43 of the terminals 15a to 15d are centered on the central axis of the brushless motor 1 as shown in FIG. Arranged on the same circle having. Each connection portion 43 of each terminal 15 is connected to a connection end portion 11 a that is drawn from the stator 3 and inserted into the coil insertion portion 25. In the present embodiment, the two connection end portions 11a arranged in each connection portion 43 are connected to the connection portion 43 by arc welding. More specifically, after the connection end portion 11a is arranged in the connection portion 43 (between the pair of coil connection portions 43a and 43b), as shown by a two-dot chain line in FIGS. 10 (a) and 10 (b). In addition, the connection part 43 is bent (caulked) so that the opening part of the connection part 43 is closed (so that the other coil connection part 43a approaches the one coil connection part 43b). Thereafter, arc welding is performed on the connection portion 43 from the distal end side of the connection end portion 11 a to join the connection end portion 11 a and the connection portion 43. In addition, as shown in FIG. 8, when joining the connection end part 11a and the connection part 43 by arc welding, each connection end part 11a has the 1st coil holding | maintenance part 26 provided in the holder 5, and the 2nd coil. Since it is held in the coil insertion portion 25 by the holding portion 27, it is difficult to jump out of the connection portion 43. Therefore, the connection end portion 11a and the connection portion 43 are more reliably joined.

  Then, by connecting the connection end portions 11 a to the respective connection portions 43, in the brushless motor 1, external power supplied from each connector portion 42 is supplied via the terminal 15 to the U-phase coil 12 and the V-phase coil. 13 and W phase coil 14 can be supplied.

As described above, the present embodiment has the following effects.
(1) Since both the first coil insertion gap 29 and the second coil insertion gap 30 are formed with a circumferential width larger than the outer diameter D of the connection end 11a, the connection end 11a It is easily inserted into the coil insertion part 25 from the outer opening through the first coil insertion gap 29 and the second coil insertion gap 30. And since it is not necessary to make the connection part 43 complicated shape, such as providing the structure for holding the connection end part 11a in the connection part 43, the connection end part in the connection part 43 of a U-shaped simple shape. 11a can be easily arranged. Further, the connection end portion 11a is disposed radially inward of the first coil holding portion 26 and the second coil holding portion 27 in the coil insertion portion 25, and the first coil holding portion 26 is displaced at two positions in the axial direction. The second coil holding portion 27 is opposed to the radial direction. Therefore, when a force that moves the connection end 11a radially outward acts on the connection end 11a, the connection end 11a contacts the first coil holding portion 26 and the second coil holding portion 27. By coming into contact with the coil insertion portion 25, it is possible to prevent the coil insertion portion 25 from going out. Therefore, the connection end portion 11 a is held in the coil insertion portion 25 by the first coil holding portion 26 and the second coil holding portion 27. As a result, the connection end portion 11a is stably held in the connection portion 43 of the terminal 15 arranged side by side with the coil insertion portion 25 in the axial direction. Then, the connection end portion 11a and the connection portion 43 are connected in a state where the connection end portion 11a is stably held in the connection portion 43, thereby reducing welding defects. As a result, defective products can be reduced.

  (2) Since the portion of the connection end portion 11a that is inclined between the surface on the holder 5 side of the stator core 6 and the installation surface 28 of the holder 5 is disposed along the guide slope 31 provided on the holder, the connection end The arrangement state of the part 11a is more stable.

  (3) Since the connecting end portion 11a is inserted into the coil insertion portion 25 from the radially outer opening, the radially outer corners of the first coil holding portion 26 and the second coil holding portion 27 are arcuate. If formed, the connection end portion 11 a can be easily inserted into the coil insertion portion 25 along the arcuate corners of the first coil holding portion 26 and the second coil holding portion 27. Further, when the connection end portion 11 a is inserted into the coil insertion portion 25, the connection end portion 11 a is suppressed from being damaged by the first coil holding portion 26 and the second coil holding portion 27.

  (4) The coil insertion portion 25 into which the connection end portion 11a is inserted is formed in the holder 5 made of synthetic resin, and the opening portion on the outer side in the radial direction is circumferential when the connection end portion 11a and the connection portion 43 are joined. Opening is unlikely. By providing the first coil holding part 26 and the second coil holding part 27 for restricting the movement of the connection end part 11a to the outer side in the radial direction on both sides in the circumferential direction of the coil insertion part 25, the connection can be made more reliably. Movement of the end portion 11a to the outside in the radial direction can be suppressed.

In addition, you may change embodiment of this invention as follows.
The two coil holding portions provided on both sides in the circumferential direction of the coil insertion portion 25 have a gap between the two coil holding portions smaller than the outer diameter of the connection end portion 11a when the holder 5 is viewed from the axial direction. It may be formed as follows. In the example shown in FIGS. 11A and 11B, the first coil holding part 51 and the second coil holding part 52 have the same radial position on both sides in the circumferential direction of the coil insertion part 25. And formed in positions shifted from each other in the axial direction. The circumferential width W3 of the first coil insertion gap 53 between the first coil holding portion 51 and the inner peripheral surface of the coil insertion portion 25 is set to a value slightly larger than the outer diameter D of the connection end portion 11a. The circumferential width W4 of the second coil insertion gap 54 between the second coil holding portion 52 and the inner peripheral surface of the coil insertion portion 25 is slightly larger than the outer diameter D of the connection end portion 11a. Is set to Furthermore, the first coil holding part 51 and the second coil holding part 52 are spaced apart in the axial direction, and an insertion gap 55 having a width W5 larger than the outer diameter D of the connection end part 11a is between them. Is provided. Also, when the holder 5 is viewed from the axial direction (same as the axial direction of the holder main body 21 and the axial direction of the fixed stator 3), it is between the first coil holding part 51 and the second coil holding part 52. The gap 56 has a circumferential width W6 smaller than the outer diameter D of the connection end 11a. The connection end portion 11a is inserted from the opening on the radially outer side of the coil insertion portion 25 through the first coil insertion gap 53, the insertion gap 55, and the second coil insertion gap 54 in order to the back of the coil insertion portion 25. Is done. When the holder 5 is viewed from the axial direction, the gap 56 between the first coil holding portion 51 and the second coil holding portion 52 has a circumferential width W6 smaller than the outer diameter of the connection end portion 11a. Out of the two connection end portions 11a inserted into the portion 25, the outer peripheral connection end portion 11a is radially displaced from the first coil holding portion 51 and the second coil holding portion 52 at two positions shifted in the axial direction. opposite. If it does in this way, the effect similar to (1) and (4) of the said embodiment can be acquired. Further, it is further suppressed that the connection end portion 11 a goes out of the coil insertion portion 25 through the space between the first coil holding portion 51 and the second coil holding portion 52.

  In the embodiment described above, the coil insertion portion 25 side and the radially outer corner of the first coil holding portion 26 have an arc shape (R shape) in which the shape seen from the axial direction swells in the circumferential direction. Similarly, the corners on the coil insertion portion 25 side and the radially outer side of each second coil holding portion 27 have an arc shape (R shape) in which the shape seen from the axial direction swells in the circumferential direction. However, the shape of the corners on the coil insertion portion 25 side and the radially outer side in the first coil holding portion 26 and the second coil holding portion 27 is not limited to an arc shape, for example, a right angle shape or a chamfered shape. May be.

In the above-described embodiment, the holder 5 includes the guide slope 31 on the side of the coil insertion portion 25, but may be configured without the guide slope 31.
The width W1 in the circumferential direction of the first coil insertion gap 29 and the width W2 in the circumferential direction of the second coil insertion gap 30 are not limited to the values in the above embodiment, but are larger than the outer diameter D of the connection end 11a. It only has to be set.

  In the above embodiment, after the other coil connection portion 43a is bent (crimped) so that the opening of the connection portion 43 is closed so that the other coil connection portion 43b is closed, the connection portion 43 is connected. The end 11a is joined. However, the connection part 43 may be joined with the connection end part 11a in a U-shaped state.

  -In above-mentioned embodiment, joining of the connection part 43 and the connection end part 11a is performed by arc welding, However, It is not restricted to this. The connection between the connection portion 43 and the connection end portion 11a may be performed by any method of fusion welding (TIG welding, laser welding, etc.) other than arc welding, resistance welding, and the like.

  In the above embodiment, the connection portion 43 has a shape in which the end portion in the longitudinal direction of the terminal body portion 41 (or a portion other than the end portion in the longitudinal direction) is folded back into a U shape. However, if the connection part 43 is a simple shape that is a part of the terminal body part 41 (including the end in the longitudinal direction) folded back, the connection part 43 has a shape other than the U shape, such as a U shape or a V shape. May be.

In the above-described embodiment, two connection end portions 11a are connected to the connection portion 43, but one connection end portion 11a may be connected to the connection portion 43.
In the above embodiment, the holder 5 is fixed with the four terminals 15, and the four terminals 15 are provided with a total of six connection portions 43. However, the number of terminals 15 fixed to the holder 5 and the number of connection portions 43 are not limited thereto, and may be appropriately changed according to the configuration of the stator 3.

  In the above embodiment, the present invention has been described by taking the brushless motor 1 provided in the power steering device for assisting the operation of the vehicle steering shaft as an example. However, the present invention may be embodied in a brushless motor for other uses. .

(A) is a side view of a brushless motor, (b) is a sectional view of the brushless motor. (A) is the side view which looked at the stator and the rotor from the holder side, (b) is sectional drawing of a stator. (A) is a top view of the holder holding the terminal, (b) is a sectional view of the holder holding the terminal. (A) is a top view of a holder, (b) is the elements on larger scale of a holder. (A) is a bottom view of the holder, (b) is a partially enlarged view of the holder. The side view of the holder seen from the opening part side of the coil insertion part. The elements on larger scale of the holder fixed to the stator. The elements on larger scale of the holder fixed to the stator. The elements on larger scale of the holder fixed to the stator. (A) is an enlarged perspective view near the connection part in the terminal, (b) is a plan view near the connection part in the terminal. (A) is a top view of the holder of another form, (b) is the partial expanded side view of the holder of another form.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Housing, 3 ... Stator, 4 ... Rotor, 5 ... Holder, 6 ... Stator core, 7 ... Teeth part, 11 ... Coil, 11a ... Connection end part, 12 ... U-phase coil as a coil, 13 ... V as a coil Phase coil, 14 ... W phase coil as coil, 15, 15a to 15d ... terminal, 25 ... coil insertion part, 26, 51 ... first coil holding part, 27, 52 ... second coil holding part, 29, 53 ... First coil insertion gap, 30, 54 ... second coil insertion gap, 31 ... guide slope, 43 ... connection portion, 56 ... gap, D ... outer diameter of connection end, W1 ... circumferential direction of first coil insertion gap Width, W2... Circumferential width of the second coil insertion gap.

Claims (5)

A substantially cylindrical stator core having a plurality of radially extending teeth portions, and a plurality of coils wound around each of the teeth portions by concentrated winding, and having a connection portion to which the connection end portions of the coils are connected A stator made of an insulating resin material holding a plurality of terminals is fixed,
The terminal has a connection portion into which the connection end portion is inserted from a radially outer side,
The holder includes a coil insertion portion that is formed at a position aligned with the connection portion in the axial direction, penetrates in the axial direction, and opens to the outside in the radial direction, and the one side in the circumferential direction of the coil insertion portion as viewed from the axial direction A first coil holding portion formed so as to have a first coil insertion gap having a circumferential width larger than an outer diameter of the connection end portion between the inner peripheral surface of the coil insertion portion and the coil insertion portion; The second coil insertion gap is formed on the other side in the circumferential direction so as to have a second coil insertion gap having a width in the circumferential direction larger than the outer diameter of the connection end portion between the inner circumferential surface of the coil insertion portion when viewed from the axial direction. A second coil holding part,
The connection end portion is disposed radially inward of the first coil holding portion and the second coil holding portion in the coil insertion portion, and the first coil holding portion and the first coil are displaced in two axial directions. A stator characterized by facing the two-coil holding portion in the radial direction. The stator according to claim 1,
The connection end portion has a portion inclined with respect to the axial direction between the axial end surface on the holder side of the stator core and the coil insertion portion into which the connection end portion is inserted,
The stator is characterized in that a guide slope is formed at an end of the holder on the side of the stator core, which is inclined according to the inclination of the connection end and guides the connection end to the coil insertion portion. The stator according to claim 1 or 2,
The first coil holding portion and the second coil holding portion have a radially outer corner portion having an arc shape. The stator according to any one of claims 1 to 3,
When the holder is viewed from the axial direction, a gap between the first coil holding portion and the second coil holding portion is smaller than an outer diameter of the connection end portion. A bottomed cylindrical housing;
The stator according to any one of claims 1 to 4, which is fixed to an inner peripheral surface of the housing;
A rotor disposed inside the stator and rotated relative to the stator by energization of the coil;
A brushless motor characterized by comprising:

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