JP2010178463A - Motor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent circuit board dislocation due to a flow of molten sealing resin without damaging the circuit board in a motor with a circuit board sealed with resin. <P>SOLUTION: The motor is provided with the circuit board 20 installed outside a rotation axis direction of a stator 2 so that it crosses a rotation axis P, a sealing resin 14 with which molds 41, 42 and 43 storing the circuit board 20 are filled in a melting state to seal the circuit board 20 from a direction crossing the rotation axis P, a center holding part 35c holding the circuit board 20 on a center side in a plane view, and a periphery holding part 13a holding the circuit board 20 on a plane view periphery side so that a shift of the circuit board 20 to the direction crossing the rotation axis P is regulated by the flow of the molten sealing resin 14 at the time of sealing the circuit board 20 with the sealing resin 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor and a manufacturing method thereof.

  Conventionally, a stator having a plurality of windings arranged in a substantially cylindrical shape around the rotation axis of the rotor, and arranged to cross the rotation axis outward in the rotation axis direction of the stator 2. Description of the Related Art A motor including a circuit board and having at least the circuit board sealed with a sealing resin is known. A motor in which the circuit board is sealed with resin as described above is disclosed in paragraphs [0052] and [0056] and FIG. 12 of Japanese Patent Application Laid-Open No. 2003-259614, for example. In such a motor, a stator and a circuit board are sandwiched between a mold fixing mold and a mold movable mold, and a molten mold resin (sealing resin) from a gate located radially outward of the stator. Is injected into the mold cavity and cured.

  As described above, the motor in which the circuit board is sealed with the sealing resin is, for example, paragraph [0043] in Japanese Patent Laid-Open No. 2003-259614, FIG. ] And FIG. Such a motor is configured such that the outer peripheral side of the circuit board is attached to an insulating portion provided in the stator core, and the circuit board is held by the stator. Thereby, when the molten sealing resin is injected from the gate, the circuit board is prevented from moving by the sealing resin.

Here, in the above Japanese Patent Application Laid-Open No. 2003-259614, paragraphs [0046], [0047], FIG. 4 and the like disclose a positioning structure for a circuit board of a molded electric motor. In the mold motor, a cylindrical bearing housing forming portion that fits into a hole portion of the circuit board is provided on the end surface of the center shaft of the mold fixing mold in order to position the circuit board at the time of molding. Is provided. Further, on the end surface of the center shaft, there is provided a fixed mold substrate fixing portion having a ridge extending in the radial direction from the bearing housing forming portion. On the other hand, a substrate fixing notch that can be fitted to the fixed mold substrate fixing portion of the mold fixing mold is also formed in the peripheral portion of the hole portion of the circuit board. That is, the circuit board is directly fixed to the mold fixing die at the peripheral edge portion of the hole.
JP 2003-259614 A JP 2007-89338 A

  By the way, as described above, as a method of manufacturing a motor in which a circuit board is sealed with a sealing resin, a sealing melted from a direction intersecting the rotation axis in a state where the circuit board is disposed between a pair of molds. There is a method of injecting a stop resin. In the case of such a manufacturing method, as in the configuration disclosed in the above Japanese Patent Application Laid-Open No. 2007-89338, in the configuration in which the circuit board is only held on the outer peripheral side of the stator, depending on the injection pressure of the sealing resin, Due to the flow of the molten sealing resin, the circuit board is caused to flow in a direction crossing the rotation axis. Therefore, when the sealing resin is injected, the position of the circuit board may be shifted from the design position.

  Then, in the connection portion formed by soldering the lead wire drawn out from the stator to the circuit board, the lead wire is pulled and cut, or a part of the resin covering the circuit board is thinned. In some cases, a part of the circuit board may be exposed without being covered with the resin. In addition, when a rotation position detecting element for detecting the rotation angle position of the rotor is mounted on the circuit board, the accurate rotation angle position of the rotor cannot be detected. There is a possibility that control cannot be performed correctly.

  On the other hand, when the stator and the circuit board are sealed with resin as in the configuration disclosed in Japanese Patent Application Laid-Open No. 2003-259614, the peripheral part of the hole formed in the central part of the circuit board It is conceivable to hold the circuit board by directly contacting the substrate with the mold. Thereby, it is possible to prevent the circuit board from flowing when the molten sealing resin is injected.

  However, the circuit board is generally made of resin, and an element for detecting the rotational angle position of the rotor, an electronic component for controlling the motor, and the like are mounted on the circuit board. Yes. Therefore, if the mold is brought into direct contact with the circuit board as described above, an excessive force is applied to the circuit board and the circuit board is damaged or the circuit board is deformed to cause an element or electronic component on the circuit board. May be damaged.

  It is an object of the present invention to provide a motor in which a circuit board is sealed with a resin so that the circuit board or the like can be prevented from being displaced due to the flow of molten sealing resin without damaging the circuit board or the like. There is in getting.

  A first invention includes a rotor having a shaft portion and configured to be rotatable about a rotation axis, and a stator having a plurality of windings arranged in a substantially cylindrical shape around the rotation axis, Injected in a molten state from a direction intersecting the rotation axis into a mold that accommodates at least the circuit board, and a circuit board arranged to intersect the rotation axis outward of the rotation axis direction of the stator When the circuit board is sealed with the sealing resin and the circuit board is sealed with the sealing resin, the circuit board moves in a direction intersecting the rotation axis by the flow of the molten sealing resin. A holding portion for holding the circuit board so as to restrict the holding, the holding portion holding the circuit board on a central side in plan view, and an outer peripheral side of the circuit board in plan view And the outer periphery holding part held by

  With the above configuration, the circuit board arranged to cross the rotation axis outward in the rotation axis direction of the stator is held by the center holding portion and the outer periphery holding portion on the center side and the outer periphery side in plan view, respectively. The Therefore, it is possible to prevent the circuit board from moving in the direction intersecting the rotation axis due to the flow of the sealing resin melted when the circuit board is sealed with the sealing resin.

  As a result, the flow of the molten sealing resin causes disconnection of the lead line drawn from the stator, the circuit board is displaced from the design position, and the resin covering the circuit board is partially thinned. It is possible to prevent a part from being exposed.

  In addition, since the circuit board is held by a plurality of holding portions in the motor rather than a molding die, the circuit board receives an excessive force and damages the circuit board and elements on the circuit board. Can be prevented.

  According to a second aspect of the present invention, there is provided a substantially cylindrical shape including a rotor having a shaft portion and configured to be rotatable about a rotation axis, and a plurality of windings arranged in a substantially cylindrical shape around the rotation axis. A motor comprising: a stator; and a circuit board disposed so as to intersect the rotation axis outward of the stator in the rotation axis direction, wherein the stator and the circuit board are sealed with a sealing resin. The manufacturing method is targeted.

  Then, the circuit board is prepared in which a hole is formed in a central portion in plan view corresponding to an inner hole formed inside the stator, and an engagement hole is formed in a peripheral portion of the hole. A circuit board preparation step and a bearing portion that rotatably supports the shaft portion of the rotor are formed in a bottomed cylindrical shape so as to cover from the outside in the direction of the rotation axis, and the circuit is formed on the opening end side thereof. A cover member preparing step of preparing a cover member formed with a protrusion that can be engaged with an engagement hole of the substrate; and a stator formed with an outer peripheral holding portion for holding the outer peripheral side in plan view of the circuit board. A stator preparing step to be prepared, and the stator and the circuit board are arranged on a first mold having a protrusion that can be inserted into an inner hole of the stator and a hole of the circuit board, and the circuit board. The stator side member which holds the outer peripheral side in plan view with the outer peripheral holding part on the stator And a cover member arranging step of arranging the cover member on the circuit board so as to cover the protrusion of the first mold and to engage the protrusion of the cover member with the engagement hole of the circuit board. And by combining the second mold with the first mold, and injecting and curing the sealing resin melted from the direction intersecting the rotation axis between these molds, the stator and And a resin sealing step of sealing the circuit board with a sealing resin.

  When the bottomed cylindrical cover member that covers the bearing portion for rotatably supporting the shaft portion of the rotor is disposed on the circuit board by the above method, the first mold is projected by the cover member. Part is covered. At this time, the cover member is disposed so that the protrusion formed on the opening end side thereof is engaged with the engagement hole of the circuit board, so that the cover member is disposed at a predetermined position, The circuit board can be held by the cover member. That is, only by attaching the cover member to the circuit board, the center portion in plan view of the circuit board can be positioned with respect to the first mold and the stator.

  Therefore, a motor in which the center side and the outer peripheral side of the circuit board are respectively held in the plan view by the cover member and the outer peripheral holding portion provided on the stator can be obtained without holding the circuit board by the molding die. Can do. That is, by the above-described method, it is possible to obtain a motor capable of suppressing the movement of the circuit board due to the flow of the resin in the direction intersecting the rotation axis while preventing damage to the circuit board and the like.

  As described above, according to the motor according to the first aspect of the present invention, since the holding portion that holds the circuit board at the center side and the outer periphery side in the plan view is provided, the molten sealing resin is held without holding the circuit board with the mold. It is possible to prevent the circuit board from moving due to the flow of. Therefore, while preventing damage to the circuit board, the circuit board is moved by the flow of the molten sealing resin to prevent the resin covering the circuit board from being thinned or the circuit board being exposed. it can.

  According to the method for manufacturing a motor according to the second invention, the outer peripheral side of the circuit board in plan view is held by the outer peripheral holding portion on the stator. Further, the circuit board is positioned with respect to the stator by a cover member that covers a bearing portion for rotatably supporting the rotor. For this reason, the central side of the circuit board can be held without increasing the number of components and the number of assembly steps, and a motor capable of suppressing the movement of the circuit board due to the flow of the molten sealing resin can be obtained. .

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a motor according to an embodiment of the present invention. 2A and 2B are a perspective view, a bottom view, and a cross-sectional view taken along line IIC-IIC in FIGS. FIG. 3 is a plan view showing a schematic configuration of the circuit board. 4A and 4B show a case where the stator is sealed with a sealing resin, in which (A) the stator and the circuit board are arranged on the core metal, (B) the bracket is arranged at the tip of the core metal, C) It is a longitudinal cross-sectional view which respectively shows the state which has arrange | positioned the upper mold | type.

  Hereinafter, embodiments will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

-Overall configuration-
FIG. 1 shows a schematic configuration of a motor 1 according to the present embodiment. The motor 1 has a rotor 3 disposed in a substantially cylindrical stator 2 and supplies power to the windings 12 of the stator 2 at a predetermined timing by a control circuit (not shown). The rotor 3 is configured to rotate with respect to the child 2. The motor 1 is used as a motor for rotating a fan, such as a drive motor for an outdoor fan of an air conditioner.

  The stator 2 includes a stator core 11 formed by laminating a plurality of steel plates, and a plurality of windings 12, 12,... Wound around the stator core 11. Although not particularly illustrated, each steel plate constituting the stator core 11 has a ring-shaped core back portion and a plurality of teeth portions projecting inward from the core back portion, and these are laminated. By doing so, the core back part and teeth part of the stator core 11 are comprised. The plurality of windings 12, 12,... Are wound around the teeth portion. That is, these windings 12, 12,... Are arranged in a substantially annular shape around the rotation axis P of the rotor 3 so as to form a substantially cylindrical space in which the rotor 3 can be accommodated. .

  As shown in FIG. 1, the portion around which the winding 12 is wound on the stator core 11 is insulated to electrically insulate between the stator core 11 and the winding 12. A portion 13 is provided. The insulating portion 13 is formed with a substantially rod-shaped outer peripheral holding portion 13 a for holding a circuit board 20 described later on the outer peripheral side in the radial direction of the stator core 11. As will be described in detail later, a plurality of outer peripheral holding portions 13a are provided so as to extend from the end surface of the substantially cylindrical stator core 11 outward in the cylinder axis direction (rotation axis direction) of the stator core 11. The front end portion of the circuit board 20 is engaged with the outer peripheral end portion.

  A circuit board 20 on which a rotational position detection circuit including a sensor 21 (rotational position detection element) for detecting the angular position of the rotor 3 is formed is disposed outside the stator 2 in the cylinder axis direction. ing. The circuit board 20 is disposed outside the stator 2 in the cylinder axis direction so as to extend in a direction intersecting the rotation axis P, that is, substantially parallel to the end surface of the substantially cylindrical stator 2. Yes. Further, the circuit board 20 is formed with a hole 20a through which the rotor 3 is inserted in a central portion in plan view (see FIG. 3).

  The stator 2 and the circuit board 20 are sealed with the sealing resin 14 in a state where the circuit board 20 is disposed on the outer side in the cylinder axis direction of the stator 2. That is, the stator 2 and the circuit board 20 are embedded in a substantially bottomed cylindrical casing 4 of the motor 1 constituted by the sealing resin 14. The casing 4 is covered at its opening side by a substantially disc-shaped cover 5, whereby a substantially columnar space for accommodating the rotor 3 is formed in the casing 4. Further, as will be described in detail later, the circuit board 20 is respectively held on the inner side and the outer side in the radial direction of the stator 2 (center side and outer side of the circuit board 20 in plan view). . For this reason, when the stator 2 and the circuit board 20 are sealed with the sealing resin 14, the movement of the circuit board 20 due to the molten sealing resin 14 is suppressed.

  Here, the configuration of the rotational position detection circuit will be briefly described. This rotational position detection circuit has three sensors 21 arranged at intervals of 120 electrical degrees (see FIG. 3). The rotational position detection circuit is configured to synthesize a signal output from the sensor 21 in accordance with the polarity of a magnet (described later) in the rotor 3 to detect the angular position of the rotor 3. Has been. That is, a sensor 21 for detecting the rotational angle position of the rotor 3 rotatably arranged in the stator 2 is mounted on the circuit board 20. The angular position of the rotor 3 detected by the rotational position detection circuit is transmitted as a rotational position signal to a control means (not shown), and the control means controls the timing of energizing the winding 13 of the stator 2. Used. As the sensor 21, for example, a Hall element is used.

  Therefore, as will be described later, by holding the circuit board 20 on the center side and the outer periphery side in a plan view, the sealing resin 14 melted when the stator 2 and the circuit board 20 are sealed with the sealing resin 14. The position of the circuit board 20 is prevented from shifting due to the flow. Accordingly, it is possible to prevent a decrease in detection accuracy of the angular position of the rotor 3 by the sensor 21, and it is possible to prevent generation of vibration and noise of the motor 1 due to a shift in detection timing of the sensor 21.

  As shown in FIG. 1, the rotor 3 is provided so as to be rotatable about a rotation axis P, and includes a shaft portion 31 and a rotor portion 32 provided on the shaft portion 31. Yes. The shaft portion 31 is rotatably supported by bearings 33 and 34. The rotor part 32 includes a cylindrical magnet 32a having a plurality of magnetic poles in the circumferential direction, and a core 32b in which silicon steel plates interposed between the magnet 32a and the shaft part 31 are laminated. The rotor section 32 is configured to obtain a rotational force by the action of a magnetic field formed by energizing the winding 12 of the stator 2 at a predetermined timing and a magnetic field of the magnet 32a.

  The bearing 33 of the rotor 3 is disposed in the casing 4 of the motor 1 and in the vicinity of the circuit board 20. The bearing 33 is covered with a substantially bottomed cylindrical bracket 35 (cover member) on the outer side of the casing from the outside in the cylinder axis direction. An insertion hole 35 a for inserting the shaft portion 31 of the rotor 2 is formed at the bottom portion of the bracket 35. On the other hand, the bearing 34 of the rotor 3 is disposed in the casing 4 of the motor 1 and on the opposite side of the stator 2 from the circuit board 20. The bearing 34 is covered with a radially inner peripheral portion of the cover 5 on the outer side of the casing.

  As shown in FIG. 1, the bracket 35 is covered with the sealing resin 14 on the outer side of the casing, but the cover 5 is not covered with the sealing resin 14. Further, reference numerals 15 and 16 in FIG. 1 denote rubbers that function as cushioning materials with the casing of the apparatus when the motor 1 is attached to the apparatus. Further, reference numeral 17 in FIG. 1 indicates that when the circuit board 20 is sealed with the sealing resin 14, the circuit board 20 does not move in the cylinder axis direction of the stator 2 due to the flow of the sealing resin 14 melted. Thus, the hole is formed by a pin (not shown) of a molding die that holds down the circuit board 20.

-Circuit board holding structure-
Next, a structure for holding the circuit board 20 when the stator 2 and the circuit board 20 are sealed with the sealing resin 14 will be described.

  The circuit board 20 is held by a substantially rod-shaped outer periphery holding portion 13 a provided on the insulating portion 13 of the stator 2 at the outer peripheral side in plan view. That is, the insulating portion 13 of the stator 2 is provided with a plurality of outer peripheral holding portions 13a. On the other hand, as shown in FIG. 3, a plurality of engaging recesses 20b, 20b,. ing. Although not particularly illustrated, the outer periphery holding portion 13 a is provided so as to surround the hole portion 20 a of the circuit board 20 so that the circuit board 20 is positioned in the radial direction with respect to the stator 2.

  Further, the circuit board 20 is held by a substantially bottomed cylindrical bracket 35 of the bearing 33 at a central portion in plan view in which the hole 20 a is formed. Specifically, as shown in FIG. 2, the bracket 35 includes a substantially bottomed cylindrical main body portion 35b having an insertion hole 35a formed in the bottom portion, and a plurality of brackets 35 provided at equal intervals in the circumferential direction at the opening end portion thereof. It has claw portions 35c (center holding portion, projection portion) (four in the illustrated example). As shown in FIGS. 2 (A) and 2 (C), each claw portion 35c is formed in an arc shape in plan view along the outer periphery of the flange portion formed on the opening side of the bracket 35. It is provided so as to protrude outward in the cylinder axis direction of the bracket 35 from the outer peripheral end portion of the flange portion. On the other hand, the circuit board 20 has a plurality of (four in the illustrated example) engagement holes in which the claw portions 35c of the bracket 35 are engaged with the peripheral edge portion of the hole portion 20a formed in the center portion in plan view. 20c, 20c,... Are formed. Each engagement hole 20c penetrates the circuit board 20 and is formed in an arc shape in plan view, like the claw portion 35c of the bracket 35.

  With this configuration, the bracket 35 has claw portions 35c, 35c,... Provided at the open end of the substantially bottomed cylindrical main body portion 35b so that the engagement holes 20c, 20c,. Are connected to the circuit board 20.

  When the stator 2 and the circuit board 20 are sealed with the sealing resin 14 by holding the outer peripheral side and the center side of the circuit board 20 in plan view as in the above configuration, the molten sealing It is possible to effectively prevent the circuit board 20 from being displaced due to the flow of the resin 14. That is, as described above, by holding the outer peripheral side and the central side of the circuit board 20 in a plan view, the molten sealing resin is compared with the conventional configuration in which only the outer peripheral side of the circuit board 20 is held. The position shift of the circuit board 20 due to the flow of 14 can be effectively prevented.

  Therefore, when the circuit board 20 is sealed with the sealing resin 14 by the outer peripheral holding part 13a of the insulating part 13 and the claw part 35c of the bracket 35, the circuit board 20 is caused by the flow of the molten sealing resin 14. A holding portion that holds the circuit board 20 is configured to restrict movement in a direction intersecting the rotation axis P.

  In the present embodiment, the claw portion 35c of the bracket 35 of the bearing 33 that rotatably supports the shaft portion 31 of the rotor 3 functions as a center holding portion for holding the center side in a plan view of the circuit board 20. To do. For this reason, it is not necessary to provide the central holding portion as a separate member, and the cost can be reduced accordingly.

  In addition, by forming the claw portion 35c of the bracket 35 and the engagement hole 20c of the circuit board 20 into a shape having a predetermined width, the contact between the claw portion 35c and the engagement hole 20c is made to be a surface contact. Can do. Further, by forming the engagement hole 20c as described above, the circuit board 20 exerts a force in the radial direction of the stator 3 (direction intersecting the rotation axis P) by the flow of the molten sealing resin 14. When received, the force received by the contact with the claw portion 35c is dispersed, and the circuit board 20 can be prevented from being damaged.

  Furthermore, by making the claw portion 35c and the engagement hole 20c arc as described above, the arc-shaped claw portion 35c can easily improve the rigidity as compared with the linear claw portion having the same surface area. . In addition, by forming the claw portion 35c in an arc shape, even when the molten sealing resin 14 flows from any of the radial directions of the stator 3 to the circuit board 20, the claw portion 35c causes the circuit board to 20 can be held more stably.

  Further, as will be described later, when the stator 2 and the circuit board 20 are sealed with the sealing resin 14, the bracket 35 is attached to the tip portion of the cored bar 41. For this reason, the circuit board 20 in which the claw portion 35 c of the bracket 35 engages with the engagement hole 20 c is fixed to the cored bar 41 through the bracket 35. When the stator 2 and the circuit board 20 are sealed with the sealing resin 14, the stator 2 is also fixed to the outer peripheral side of the cored bar 41. For this reason, the circuit board 20 is fixed in a state of being positioned with respect to the core metal 41 and the stator 2 through the bracket 35.

  Therefore, with the configuration as described above, the central side of the circuit board 20 can be held with respect to the cored bar 41 and the stator 2 only by mounting the bracket 35 on the circuit board 20, and the motor 1 can be Workability at the time of manufacturing can be improved.

-Motor manufacturing method-
Below, the manufacturing method of the motor 1 which has the above structures is demonstrated.

  First, steel plates are laminated to form a substantially cylindrical stator core 11, and then an insulating portion 13 is disposed on the stator core 11. The insulating portion 13 is a pair of resin molded products having a shape corresponding to the surface shape of the stator core 11 and is configured to be fitted on both sides of the stator core 11 in the cylinder axis direction. .

  After the insulating portion 13 is disposed on the stator core 11, a coil is wound on the insulating portion 13 to form the winding 12. On the other hand, a circuit board 20 is prepared in which a hole 20a is formed in the central portion in plan view and a plurality of engagement holes 20c are formed in the peripheral portion of the hole 20a. A substantially bottomed cylindrical bracket 35 having a plurality of claw portions 35c formed on the opening side is also prepared.

  Next, the circuit board 20 provided with the rotational position detection circuit for detecting the angular position of the rotor 3 is engaged with the outer peripheral holding portion 13 a of the insulating portion 13. Thereby, the circuit board 20 is held on the radially outer peripheral side of the stator 2. The hole 20a formed in the circuit board 20 is an inner hole formed inside the stator core 11 in a state where the circuit board 20 is combined with the substantially cylindrical stator core 11. It is formed to correspond.

  Here, since the circuit board 20 is formed in a substantially rectangular shape in plan view composed of three straight lines and one curve, it is easy to determine the directionality in plan view. Therefore, the circuit board 20 can be easily positioned with respect to the stator 3 and can be easily attached to the stator 3. The end of the winding 12 of the stator 3 is electrically connected to a predetermined part of the circuit board 20 by soldering. Note that the end of the winding 12 of the stator 3 may be electrically connected to a predetermined portion of the circuit board 20 via a connection pin held by the insulating portion 13.

  Then, as shown in FIG. 4A, the stator 3 and the circuit board 20 combined as described above are arranged on a substantially cylindrical cored bar 41. The metal core 41 is formed on the outer peripheral side surface so as to be able to hold the stator 3, and the tip portion having a smaller diameter than the portion holding the stator 3 is a hole in the circuit board 20. It is formed so as to be inserted through 20a. Thereby, the stator 3 and the circuit board 20 are held with respect to the core metal 41 in a state where the tip end portion of the core metal 41 protrudes upward from the circuit board 20. As shown in FIG. 4A, the core metal 41 is held by a lower mold 42, and the core metal 41 and the lower mold 42 constitute a first molding die.

  After disposing the stator 3 and the circuit board 20 on the core metal 41 as described above, as shown in FIG. 4B, the tip of the core metal 41 protruding upward from the circuit board 20 It arrange | positions so that the substantially bottomed cylindrical bracket 35 may be covered. At this time, the bracket 35 is attached so that the claw portion 35 c engages with the engagement hole 20 c of the circuit board 20. Thereby, the bracket 35 is positioned with respect to the cored bar 41, and the bracket 35 and the circuit board 20 are engaged with each other, so that the circuit board 20 can be held with respect to the cored bar 41.

  Then, an upper die 43 (second molding die) is combined on the lower die 42 holding the cored bar 41 so that a predetermined space is formed around the stator 3 and the circuit board 20 (FIG. 4 ( C)). Thereafter, molten sealing resin 14 is injected into the space from the gate 44 provided at the joint of the lower mold 42 and the upper mold 43.

  At this time, the gate 44 is provided so as to extend in the radial direction of the stator 3, and the molten sealing resin 14 injected through the gate 44 is in the radial direction of the stator 3 (in FIG. (See the white arrow). For this reason, the radial force of the stator 3 acts on the circuit board 20. However, in the present embodiment, the circuit board 20 is held on the center side and the outer peripheral side in plan view. For this reason, the circuit board 20 is less likely to be displaced due to the flow of the molten sealing resin 14 as compared with the case of the conventional configuration held only on the outer peripheral side. The circuit board 20 is held by the bracket 35 at the peripheral portion of the hole 20a formed in the central portion in plan view. For this reason, a deformation | transformation arises in the center part with comparatively low intensity | strength within this circuit board 20, or the circuit board 20 moves with respect to the metal core 41 which penetrates the said hole 20a with the fuse | melting sealing resin 14. Can be prevented.

  After injecting the molten sealing resin 14 between the lower mold 42 and the upper mold 43 as described above, the sealing resin 14 is cured and sealed from the lower mold 42, the upper mold 43 and the cored bar 41. The stator 3, the bracket 35, and the circuit board 20 that are sealed with the stop resin 14 are removed. Thereafter, the bearings 33 and 34, the rotor 3 and the cover 5 are attached to obtain the motor 1 as shown in FIG.

  Here, in the step of preparing the circuit board 20 in which the hole 20a and the engagement hole 20c are formed, the hole 20a is formed in the central portion in plan view corresponding to the inner hole formed inside the stator 2. This corresponds to the circuit board preparation step of preparing the circuit board 20 in which the engagement hole 20c is formed in the peripheral portion of the hole 20a.

  In addition, the step of preparing the substantially bottomed cylindrical bracket 35 provided with the claw portion 35c on the opening side, the bearing 33 for rotatably supporting the shaft portion 31 of the rotor 3 is arranged outside the cylinder axis direction of the stator 2. Cover member preparing step of preparing a bracket 35 that is formed in a bottomed cylindrical shape so as to cover from the side, and that is formed with a claw portion 35c that can be engaged with the engagement hole 20c of the circuit board 20 on the opening end side thereof Corresponding to

  Further, the step of disposing the insulating portion 13 provided with the outer peripheral holding portion 13a on the teeth portion of the stator core 11 is fixed with the outer peripheral holding portion 13a for holding the outer peripheral side of the circuit board 20 in plan view. This corresponds to the stator preparation step for preparing the child 2.

  The step of holding the outer peripheral side of the circuit board 20 by the outer peripheral holding part 13a of the insulating part 13 of the stator 2 and the process of inserting the tip end portion of the cored bar 41 into the hole 20a of the circuit board 20 are fixed. The core 2 and the circuit board 20 are disposed on a cored bar 41 having an inner hole of the stator 2 and a tip portion that can be inserted into the hole 20a of the circuit board 20, and the circuit board 20 has an outer peripheral side in plan view. This corresponds to the stator side member arranging step in which the outer peripheral holding portion 13a on the stator 2 is held.

  Further, the step of disposing the bracket 35 so that the claw portion 35 c engages with the engagement hole 20 c of the circuit board 20 at the front end portion of the core metal 41 covers the front end portion of the core metal 41 and the circuit board 20. This corresponds to the cover member arranging step of arranging the bracket 35 on the circuit board 20 so that the claw portion 35c of the bracket 35 is engaged with the engaging hole 20c.

  Further, in a state where the core metal 41, the lower mold 42 and the upper mold 43 are combined, the molten sealing resin 14 is injected into a space formed between them, and the stator 2 and the circuit board 20 are sealed with the sealing resin. 14, the upper mold 43 is combined with the core metal 41 and the lower mold 42, and the molten sealing resin 14 is injected between these molds from the direction intersecting the rotation axis P. By curing, it corresponds to the resin sealing step of sealing the stator 2 and the circuit board 20 with the sealing resin 14.

-Effect of the embodiment-
As described above, in the present embodiment, the substantially cylindrical stator 2 and the circuit board 20 disposed so as to intersect the rotation axis P outward in the cylinder axis direction of the stator 2 are formed by the sealing resin 14. When sealing, not only the outer peripheral side but also the central side in the plan view of the circuit board 20 was held. For this reason, it is possible to prevent the position of the circuit board 20 from being shifted from the design position by the flow of the molten sealing resin 14. Thus, the entire circuit board 20 can be covered with the sealing resin 14 without exposing a part of the circuit board 20 or partially reducing the thickness of the sealing resin 14. In addition, by preventing the position shift of the circuit board 20 as described above, the position of the sensor 21 mounted on the circuit board 20 is shifted in order to detect the rotation position of the rotor 3, and the rotor 3 It can prevent that the detection accuracy of a rotation position falls.

  Moreover, the circuit board 20 engages the claw portion 35c formed on the bracket 35 of the bearing 33 that rotatably supports the shaft portion 31 of the rotor 3 with the engagement hole 20c of the circuit board 20. Thus, the central portion is held in plan view. For this reason, the motor 1 which can obtain the above effects can be manufactured at low cost without using a separate member.

  Furthermore, by forming the claw portion 35c of the bracket 35 and the engagement hole 20c of the circuit board 20 in a shape having a predetermined width such as an arc shape, the force acting on the circuit board 20 can be dispersed. In addition, by forming the engagement hole 20c as described above, the bracket 12 can be used regardless of the direction in which the sealing resin 14 melted with respect to the circuit board 20 crosses the cylinder axis of the stator 2. 35.

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

  In the above embodiment, the claw portion 35c of the bracket 35 and the engagement hole 20c of the circuit board 20 are each formed in an arc shape, but this is not restrictive. For example, the shape may be any shape as long as the claw portion and the hole portion can be engaged, such as a straight line shape. Further, the claw portion may be formed in a pin shape, or the engagement hole 20c may be a round hole or a square hole. In the above embodiment, the four claw portions 35c and the four engagement holes 20c are provided. However, the present invention is not limited to this, and if the circuit board 20 can be prevented from flowing due to the flow of the molten sealing resin 14, It may be 5 or less, or 5 or more.

  Moreover, in the said embodiment, while the outer peripheral side of the circuit board 20 is hold | maintained by the outer periphery holding | maintenance part 13a of the insulating part 13, and the center part of this circuit board 20 is hold | maintained by the bracket 35, it is not this limitation. Provide another member for holding the outer peripheral side and the central portion of the circuit board 20, or provide a holding portion for holding both the outer peripheral side and the central portion of the circuit board 20 in the insulating portion 13, etc. Any configuration is possible as long as the circuit board 20 can be held on the outer peripheral side and the central portion.

  Furthermore, in the said embodiment, although the circuit board 20 and the whole stator 2 are sealed with the sealing resin 14, it is not this limitation. If the entire circuit board 20 is sealed with the sealing resin 14, the stator 2 may be partially sealed with the sealing resin 14 or not sealed with the sealing resin 14. Good.

  As described above, the present invention is useful for a motor in which a circuit board is disposed outside the stator in the cylinder axis direction and the circuit board is sealed with a sealing resin.

DESCRIPTION OF SYMBOLS 1 Motor 2 Stator 3 Rotor 12 Winding 13 Insulation part 13a Outer periphery holding part 14 Sealing resin 20 Circuit board 20a Hole part 20c Engagement hole 21 Sensor (rotation position detection element)
31 Shaft 33 Bearing (Bearing)
34 Bearing 35 Bracket (Cover member)
35c Claw part (projection part, center holding part)
41 Core metal (mold, first mold)
42 Lower mold (mold, first mold)
43 Upper mold (molding die, second molding die)
44 Gate P Rotation axis

Claims (6)

A rotor having a shaft portion and configured to be rotatable about a rotation axis;
A stator having a plurality of windings arranged in a substantially cylindrical shape around the rotation axis;
A circuit board disposed so as to intersect the rotation axis outward of the rotation axis of the stator;
A sealing resin that seals the circuit board by being injected in a molten state from a direction intersecting the rotation axis into a mold that houses at least the circuit board;
When sealing the circuit board with the sealing resin, the circuit board is held so as to restrict movement of the circuit board in a direction intersecting the rotation axis by the flow of the molten sealing resin. And a holding part that
The holding part is a motor including a central holding part that holds the circuit board on a central side in a plan view and an outer peripheral holding part that holds the circuit board on an outer peripheral side in a plan view. The motor according to claim 1,
The circuit board has a hole formed in the center portion in plan view,
The center holding portion is a motor configured to hold the circuit board at a peripheral portion of the hole portion. The motor according to claim 2,
A bearing portion rotatably supporting the shaft portion of the rotor;
A bottomed cylindrical cover member that covers the bearing portion from the outside in the rotational axis direction;
The center holding part is composed of a protrusion formed on the opening end side of the cover member,
The motor in which the engagement hole which can be engaged with the said projection part is formed in the peripheral part of the said hole part in the said circuit board. The motor according to claim 3, wherein
The motor in which the protrusion and the engagement hole are formed in an arc shape in plan view. The motor according to any one of claims 1 to 4,
A motor on which a rotational position detecting element for detecting a rotational angle position of a rotor rotatably arranged in the stator is mounted on the circuit board. A rotor having a shaft portion and configured to be rotatable about a rotation axis; a substantially cylindrical stator having a plurality of windings arranged in a substantially cylindrical shape around the rotation axis; and the fixing A circuit board disposed so as to intersect the rotation axis outside the rotation axis direction of the child, and a method of manufacturing a motor in which the stator and the circuit board are sealed with a sealing resin.
A circuit board for preparing the circuit board in which a hole is formed in a central portion in plan view corresponding to an inner hole formed inside the stator, and an engagement hole is formed in a peripheral portion of the hole. A preparation process;
The bearing portion that rotatably supports the shaft portion of the rotor is formed in a bottomed cylindrical shape so as to cover from the outside in the rotation axis direction, and the opening end side is formed in the engagement hole of the circuit board. A cover member preparation step of preparing a cover member on which an engaging protrusion is formed;
A stator preparation step of preparing a stator in which an outer peripheral holding portion for holding the outer peripheral side in plan view of the circuit board is formed;
The stator and the circuit board are arranged on a first mold having a protrusion that can be inserted into the inner hole of the stator and the hole of the circuit board, and the outer peripheral side in plan view of the circuit board is positioned on the stator. A stator side member arrangement step for holding the upper outer periphery holding portion;
A cover member disposing step of covering the projecting portion of the first mold and disposing the cover member on the circuit board so that the protrusion of the cover member is engaged with the engagement hole of the circuit board;
The stator and the circuit board are formed by combining the second mold with the first mold and injecting and curing a sealing resin melted from the direction intersecting the rotation axis between the molds. And a resin sealing step of sealing the substrate with a sealing resin.

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