JP2018143048A - Method for molding resin casing and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for molding a motor, in which a metal mold is inhibited from being damaged and deformed.SOLUTION: A motor includes a resin casing covering a stator at least partially. Each of a plurality of divided cores 40 constituting a stator core includes: a core back 41; and a tooth 42 extending to one side in the radial direction from the core back. An insulator 212 includes a contact surface further protruding to one side in the radial direction than the tip of the tooth in the radial direction. During molding the resin casing, the contact surface comes into contact with a first metal mold 81 in the radial direction.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a resin casing molding method and a motor that at least partially covers a stator of a motor.

Conventionally, a so-called molded motor in which a stator is covered with a resin is known. The molded motor is excellent in the waterproofness of the stator and the vibration and soundproofing properties when the motor is driven. For example, a stator in which a plurality of divided cores are arranged in the circumferential direction is used. In the manufacturing process of the molded motor, the resin is formed around the stator by pouring the resin into a mold in which the stator is inserted. About the manufacturing method of such a molded motor, it describes in Unexamined-Japanese-Patent No. 2001-268862, for example.
JP 2001-268862 A

  In the manufacturing method disclosed in Japanese Patent Laid-Open No. 2001-268862, by holding the outer peripheral portion of the stator with a mold, self-weight is applied to the inner diameter side of the stator, and the stator core is brought into close contact with the mold core. This improves the accuracy of the roundness, cylindricity, and coaxiality of the inner diameter of the stator constituted by the split core (see paragraph 0015 of the document). However, when a metallic stator is brought into contact with the mold, the mold is easily damaged or deformed. For this reason, the lifetime of a metal mold | die becomes short. Further, when the mold is deformed, the resin may flow into a place where the resin should not flow, and an unnecessary resin thin film may be formed.

  An object of the present invention is to provide a technique capable of accurately arranging a plurality of divided cores in an annular shape when molding a resin casing covering a stator and suppressing damage and deformation of a mold.

  An exemplary first invention of the present application is a method for molding a resin casing that at least partially covers a stator of a motor. A) When combined with each other, an annular cavity centering on a vertically extending central axis is formed inside. A step of preparing a first die and a second die, and b) a step of arranging the stator in the first die; c) a combination of the first die and the second die A step in which the stator is accommodated in the cavity; d) a step of pouring a resin in a fluid state into the cavity; and e) curing the resin to thereby provide the stator and the resin casing. A step of obtaining a unit, f) a step of separating the first mold and the second mold, and g) a step of taking out the unit from the first mold or the second mold. And the stator A magnetic core having a core back and teeth extending radially outward from the core back, a plurality of stator cores arranged in the circumferential direction, a resin insulator covering at least the teeth, and the insulator. And a coil made of a conductive wire wound around the teeth, and the insulator has a contact surface protruding to one side in the radial direction from the radial tip of the teeth, and the steps b) to e). The contact surface is in radial contact with the first mold.

  An exemplary second invention of the present application is a method of molding a resin casing that at least partially covers a stator of a motor, and a) by combining them together, an annular cavity centering on a vertically extending central axis is contained inside A step of preparing a first die and a second die, and b) a step of arranging the stator in the first die; c) a combination of the first die and the second die A step in which the stator is accommodated in the cavity; d) a step of pouring a resin in a fluid state into the cavity; and e) curing the resin to thereby provide the stator and the resin casing. A step of obtaining a unit, f) a step of separating the first mold and the second mold, and g) a step of taking out the unit from the first mold or the second mold. And the stator A magnetic core having a core back and teeth extending radially outward from the core back, a plurality of stator cores arranged in the circumferential direction, a resin insulator covering at least the teeth, and the insulator. A coil made of a conductive wire wound around the teeth, and the insulator is made of a thermoplastic resin, and has a contact surface having the same radial position as the radial tip of the teeth, In the steps b) to e), the contact surface comes into contact with the first mold in the radial direction.

  An exemplary third invention of the present application is a motor including a stator and a resin casing that at least partially covers the stator, and the stator extends from the core back and the core back to one side in the radial direction. A stator core in which a plurality of magnetic cores having teeth are arranged in the circumferential direction, a resin insulator covering at least the teeth, and a coil made of a conductive wire wound around the teeth via the insulator, And the insulator has an exposed surface that protrudes to one side in the radial direction from the radial tip of the tooth and is exposed from the resin casing.

  According to the first and second exemplary inventions of the present application, the plurality of split cores can be arranged in an annular shape with high accuracy by bringing the contact surface of the insulator into contact with the first mold. Further, since the resin insulator is brought into contact with the first mold, damage and deformation of the first mold can be suppressed as compared with the case where the metal teeth are brought into contact with the first mold.

  According to the third exemplary invention of the present application, when the resin casing is molded, the plurality of split cores can be accurately arranged in an annular shape by bringing the exposed surface of the insulator into contact with the first mold. Further, since the resin insulator is brought into contact with the first mold, damage and deformation of the first mold can be suppressed as compared with the case where the metal teeth are brought into contact with the first mold.

FIG. 1 is a side view of the motor. FIG. 2 is a longitudinal sectional view of the motor. FIG. 3 is a partial longitudinal sectional view of the stator, the circuit board, and the resin casing. FIG. 4 is a top view of the stator and the resin casing. FIG. 5 is a bottom view of the stator and the resin casing. FIG. 6 is an internal view of the stator and the resin casing. FIG. 7 is a flowchart showing a manufacturing procedure of the stator and the resin casing. FIG. 8 is a view showing a state of manufacturing the stator and the resin casing. FIG. 9 is a view showing a state of manufacturing the stator and the resin casing. FIG. 10 is a diagram showing a state of manufacturing the stator and the resin casing. FIG. 11 is a view showing a state of manufacturing the stator and the resin casing. FIG. 12 is a view showing a state of manufacturing the stator and the resin casing. FIG. 13 is an internal view of a stator and a resin casing according to a modification. FIG. 14 is a longitudinal sectional view of a motor according to a modification.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In this application, the direction parallel to the central axis of the motor is the “axial direction”, the direction orthogonal to the central axis of the motor is the “radial direction”, and the direction along the arc centered on the central axis of the motor is the “circumferential direction”. , Respectively. Moreover, in this application, the shape and positional relationship of each part are demonstrated by making an axial direction into an up-down direction. However, the definition of the vertical direction is not intended to limit the orientation of the motor according to the present invention during manufacture and use.

<1. Overall configuration of motor>
FIG. 1 is a side view of the motor 1. FIG. 2 is a longitudinal sectional view of the motor 1. The motor 1 of this embodiment is used for household appliances such as an air conditioner. However, the motor of the present invention may be used for applications other than home appliances. For example, the motor of the present invention may be mounted on transportation equipment such as automobiles and railways, OA equipment, medical equipment, tools, industrial large equipment, and the like to generate various driving forces.

  As shown in FIGS. 1 and 2, the motor 1 has a stationary part 2 and a rotating part 3. The stationary part 2 is fixed to the frame of the home appliance. The rotating unit 3 is supported so as to be rotatable with respect to the stationary unit 2.

  The stationary part 2 of the present embodiment includes a stator 21, a circuit board 22, a resin casing 23, a lower bearing part 24, and an upper bearing part 25.

  The stator 21 is an armature that generates a magnetic flux according to a drive current. The stator 21 includes a stator core 211, an insulator 212, and a plurality of coils 213. The stator core 211 is composed of a plurality of divided cores 40. The split core 40 is made of, for example, a laminated steel plate in which electromagnetic steel plates that are magnetic materials are laminated in the axial direction. The plurality of divided cores 40 are arranged in the circumferential direction. Each divided core 40 has a core back 41 and a tooth 42. The plurality of core backs 41 come into contact with each other to form an annular shape centering on the central axis as a whole. The teeth 42 extend radially inward from the core back 41.

  The insulator 212 is attached to the stator core 211. As a material of the insulator 212, a resin which is an insulator is used. The insulator 212 includes a tooth insulating portion 51 that covers both end surfaces in the axial direction and both surfaces in the circumferential direction of each tooth 42. The coil 213 is made of a conductive wire wound around the tooth insulating portion 51. That is, the conducting wire constituting the coil 213 is wound around the tooth 42 via the tooth insulating portion 51 of the insulator 212.

  Further, as shown in FIG. 2, the insulator 212 has a wall portion 52 on the radially inner side of the coil 213. The wall portion 52 extends from the radially inner end of the tooth insulating portion 51 toward the upper side in the axial direction, the lower side in the axial direction, and both sides in the circumferential direction. The wall portion 52 suppresses the coil 213 from collapsing and prevents the conducting wire constituting the coil 213 from protruding inward in the radial direction.

  The circuit board 22 is positioned on the upper side in the axial direction of the stator 21 and is disposed substantially perpendicular to the central axis 9. The circuit board 22 is fixed to the upper end portion of the insulator 212 by, for example, welding. An electric circuit for supplying a drive current to the coil 213 is mounted on the circuit board 22. An end portion of the conductive wire constituting the coil 213 is electrically connected to an electric circuit on the circuit board 22. The current supplied from the external power source flows to the coil 213 through the circuit board 22.

  The resin casing 23 is a resin member that holds the stator 21 and the circuit board 22. The resin casing 23 is obtained by pouring resin into a cavity in a mold in which the stator 21 and the circuit board 22 are accommodated. That is, the resin casing 23 is a resin molded product using the stator 21 and the circuit board 22 as insert parts. Therefore, the stator 21 and the circuit board 22 are at least partially covered with the resin casing 23.

  The resin casing 23 of the present embodiment has a cylindrical portion 231 and a top plate portion 232. The cylindrical portion 231 extends in a substantially cylindrical shape in the axial direction. At least the core back 41 of the stator 21 is covered with a resin constituting the cylindrical portion 231. Further, a rotor 32 described later is disposed inside the cylindrical portion 231 in the radial direction. The top plate portion 232 extends radially inward from the cylindrical portion 231 on the upper side in the axial direction than the stator core 211 and the rotor 32. In the center of the top plate portion 232, a circular hole 233 for passing a shaft 31 described later is provided.

  The lower bearing portion 24 rotatably supports the shaft 31 on the lower side in the axial direction than the rotor 32. The upper bearing portion 25 rotatably supports the shaft 31 on the upper side in the axial direction than the rotor 32. As the lower bearing portion 24 and the upper bearing portion 25 of the present embodiment, ball bearings in which a plurality of spheres are interposed between the inner ring and the outer ring are used. The outer ring of the lower bearing portion 24 is fixed to the cylindrical portion 231 of the resin casing 23 via a metal lower cover member 241. The outer ring of the upper bearing portion 25 is fixed to the top plate portion 232 of the resin casing 23 via a metal upper cover member 251. However, other types of bearings such as a slide bearing and a fluid bearing may be used instead of the ball bearing.

  The rotating unit 3 according to the present embodiment includes a shaft 31 and a rotor 32.

  The shaft 31 is a columnar member extending in the axial direction. The shaft 31 is supported by the lower bearing portion 24 and the upper bearing portion 25 and rotates around the central axis 9. The upper end portion of the shaft 31 protrudes upward in the axial direction from the upper surface of the resin casing 23. For example, a fan for an air conditioner is attached to the upper end portion of the shaft 31. However, the shaft 31 may be connected to a drive unit other than a fan via a power transmission mechanism such as a gear.

  The shaft 31 of the present embodiment protrudes upward in the axial direction of the resin casing 23, but the present invention is not limited to this. The shaft 31 may protrude downward in the axial direction of the resin casing 23, and the lower end portion thereof may be connected to the drive unit. Further, the shaft 31 may project both on the upper side in the axial direction and on the lower side in the axial direction of the resin casing 23, and both the upper end portion and the lower end portion thereof may be connected to the drive unit.

  The rotor 32 is fixed to the shaft 31 and rotates together with the shaft 31. The rotor 32 has a rotor core 321 and a plurality of magnets 322. The rotor core 321 is made of a laminated steel plate in which electromagnetic steel plates, which are magnetic materials, are laminated in the axial direction. The plurality of magnets 322 are disposed on the outer peripheral surface of the rotor core 321. The radially outer surface of each magnet 322 is a magnetic pole surface that faces the end surface of the teeth 42 on the radially inner side in the radial direction. The plurality of magnets 322 are arranged at equal intervals in the circumferential direction so that N-pole magnetic pole faces and S-pole magnetic pole faces are alternately arranged.

  Instead of the plurality of magnets 322, a single annular magnet may be used. In the case of using an annular magnet, it is only necessary that the N pole and the S pole are alternately magnetized in the circumferential direction on the outer peripheral surface of the magnet. The magnet may be embedded in the rotor core. Further, the magnet may be molded from a resin containing magnetic powder and connected to the shaft 31.

  When the motor 1 is driven, a drive current is supplied to the coil 213 through the circuit board 22. Then, magnetic flux is generated in the plurality of teeth 42 of the stator core 211. A circumferential torque is generated by the action of the magnetic flux between the teeth 42 and the magnet 322. As a result, the rotating unit 3 rotates about the central axis 9.

<2. About the shape of the insulator near the wall>
Next, the shape near the wall 52 of the insulator 212 will be further described. FIG. 3 is a partial longitudinal sectional view of the stator 21, the circuit board 22, and the resin casing 23. FIG. 4 is a top view of the stator 21 and the resin casing 23. FIG. 5 is a bottom view of the stator 21 and the resin casing 23. FIG. 6 is an inner surface view of the stator 21 and the resin casing 23. 4 and 5, the circuit board 22 is not shown in order to avoid complication of the drawings.

  As shown in FIGS. 3 to 6, the wall portion 52 of the insulator 212 includes an upper wall portion 61, a lower wall portion 62, a first side wall portion 63, and a second side wall portion 64.

  The upper wall portion 61 is located above the teeth 42. The upper wall portion 61 extends from the radially inner end of the upper surface of the tooth insulating portion 51 to the upper side in the axial direction. The upper wall portion 61 has an upper inner side surface 611 that is a radially inner surface. The upper inner side surface 611 extends in the axial direction and the circumferential direction on the radially inner side than the distal end on the radially inner side of the tooth 42. That is, the upper inner surface 611 protrudes radially inward from the radially inner tip of the tooth 42. Further, at least a part of the upper inner surface 611 is an exposed surface exposed from the resin casing 23. The exposed surface of the upper inner surface 611 faces the radially outer surface of the magnet 322 in the radial direction. The exposed surface of the upper inner surface 611 is a contact surface that comes into contact with the mold in the radial direction when the resin casing 23 described later is molded.

  The lower wall portion 62 is located below the teeth 42. The lower wall portion 62 extends from the radially inner end of the lower surface of the tooth insulating portion 51 to the lower side in the axial direction. The lower wall portion 62 has a lower inner side surface 621 that is a radially inner surface. At least a part of the lower inner side surface 621 extends in the axial direction and the circumferential direction on the radially outer side than the distal end on the radially inner side of the tooth 42. The lower surface 421 of the tooth 42 is exposed from the insulator 212 and the resin casing 23 between the radially inner tip of the tooth 42 and the lower inner side surface 621. The lower surface 421 of the teeth 42 contacts the mold in the axial direction when the resin casing 23 described later is molded.

  Further, the lower wall portion 62 has a wall protruding portion 622. The wall protrusion 622 is located on the circumferential center line of the tooth 42 and protrudes radially inward from the lower inner side surface 621 of the lower wall 62. In the present embodiment, the radial position of the radially inner surface of the wall protruding portion 622 is the same as the radial position of the radially inner tip of the tooth 42. Further, at least a part of the lower inner side surface 621 is an exposed surface exposed from the resin casing 23. The exposed surface of the lower inner surface 621 faces the radially outer surface of the magnet 322 in the radial direction. The exposed surface of the lower inner side surface 621 becomes a contact surface that comes into contact with the mold in the radial direction when the resin casing 23 described later is molded.

  The first side wall 63 is located on one side in the circumferential direction of the tip of the tooth 42. The first side wall 63 extends from the radially inner end of one side surface in the circumferential direction of the tooth insulating portion 51 to one side in the circumferential direction. The first side wall 63 has a first end face 631 located at one end in the circumferential direction. The first end face 631 is inclined with respect to the radial direction and the circumferential direction.

  The second side wall portion 64 is located on the other side in the circumferential direction at the tip of the tooth 42. The second side wall portion 64 extends from the radially inner end of the other side surface in the circumferential direction of the tooth insulating portion 51 to the other side in the circumferential direction. The 2nd side wall part 64 has the 2nd end surface 641 located in the edge part of the other side of the circumferential direction. The second end face 641 is inclined with respect to the radial direction and the circumferential direction.

  The first end surface 631 and the second end surface 641 are located between the teeth 42 adjacent in the circumferential direction. As shown in FIG. 4, when viewed in the axial direction, the first end surface 631 and the second end surface 641 overlap in the radial direction. The first end surface 631 and the second end surface 641 face each other through contact or a slight gap.

<3. Manufacturing procedure of stator and resin casing>
Then, the manufacturing procedure of the stator 21 and the resin casing 23 mentioned above is demonstrated. FIG. 7 is a flowchart showing a manufacturing procedure of the stator 21 and the resin casing 23. 8 to 12 are views showing a state of manufacturing the stator 21 and the resin casing 23.

  When the stator 21 and the resin casing 23 are manufactured, first, a plurality of divided cores 40 are formed (step S1). The plurality of divided cores 40 are formed, for example, by laminating electromagnetic steel sheets punched into a predetermined shape in the axial direction. The plurality of split cores 40 may be formed individually or may be formed in a state of being connected in a straight line via a flexible thin portion. Moreover, the some division | segmentation core 40 may be linearly connected by the insulator 212 provided in following step S2.

  Next, the insulator 212 is provided in each divided core 40 (step S2). The insulator 212 is formed by resin molding using the split core 40 as an insert part, for example. However, the insulator 212 may be molded separately from the split core 40 and the molded insulator 212 may be attached to the split core 40.

  Subsequently, the coil 213 is formed (step S3). Specifically, a conducting wire is wound around the teeth insulating portion 51 of the insulator 212. Thereby, the coil 213 is formed around the teeth 42 of each divided core 40 via the insulator 212.

  Thereafter, the plurality of divided cores 40 are arranged in an annular shape (step S4). In the present embodiment, the plurality of divided cores 40 are arranged such that the teeth 42 are radially inward of the core back 41. FIG. 8 is a top view showing a state in which a plurality of divided cores 40 arranged in a straight line are bent into an annular shape. When the plurality of split cores 40 are bent into an annular shape, the end faces in the circumferential direction of the core backs 41 of the adjacent split cores 40 are in contact with each other. At this time, between the teeth 42 adjacent in the circumferential direction, the first end surface 631 of the first side wall 63 of the insulator 212 and the second end surface 641 of the second side wall 64 have a contact or a slight gap. Through each other. Thereby, the space between the teeth 42 adjacent in the circumferential direction is closed by the first side wall portion 63 and the second side wall portion 64.

  In the present embodiment, the first end surface 631 and the second end surface 641 are both inclined surfaces that are inclined with respect to the radial direction and the circumferential direction. Accordingly, as shown in FIG. 8, when the plurality of split cores 40 connected in a straight line are bent into an annular shape, the first end surface 631 and the second end surface 641 are unlikely to interfere with each other. Therefore, the operation | work which bends the some division | segmentation core 40 to a ring shape becomes easy.

  When the plurality of divided cores 40 are arranged in an annular shape, next, the circuit board 22 is fixed to the upper side of the plurality of divided cores 40. The circuit board 22 is welded to the insulator 212, for example. Thereafter, the stator 21 to which the circuit board 22 is fixed is inserted into the first mold 81.

  Next, a first mold 81 and a second mold 82 for injection molding are prepared (step S5). The first mold 81 and the second mold 82 are combined with each other so that an annular cavity 83 corresponding to the shape of the resin casing 23 is generated inside them. And the stator 21 and the circuit board 22 are arrange | positioned inside the 1st metal mold | die 81 (step S6).

  As shown in FIG. 9, the first mold 81 has a cored bar portion 811. The cored bar portion 811 is a columnar part extending along the central axis 9. On the other hand, as described above, the upper inner side surface 611 of the insulator 212 protrudes radially inward from the distal end of the teeth 42 on the radially inner side. When the stator 21 is inserted into the first mold 81, the radially inner surface of the upper inner surface 611 and the radially inner surface of the wall protruding portion 622 become the outer peripheral surface of the core metal portion 811. Contact. That is, in the present embodiment, the upper inner surface 611 and the radially inner surface of the wall protrusion 622 are contact surfaces that contact the first mold 81 in the radial direction. This contact continues at least until step S9 described later.

  In this way, by bringing the insulator 212 into contact with the outer peripheral surface of the cored bar portion 811, the plurality of divided cores 40 are accurately aligned in an annular shape. Further, not the tip of the metal tooth 42 but a resin insulator 212 is brought into contact with the cored bar portion 811. For this reason, damage to the first mold 81 can be suppressed as compared with the case where the metal teeth 42 are brought into contact with the cored bar portion 811.

  In particular, in the present embodiment, not only the upper inner surface 611 of the upper wall portion 61 but also the wall protruding portion 622 provided on the lower wall portion 62 contacts the cored bar portion 811. Thereby, each division | segmentation core 40 can be more accurately positioned with respect to the metal core part 811. FIG. Further, the wall protrusion 622 is located on the center line in the circumferential direction of the tooth 42. For this reason, the cored bar portion 811 and the wall protruding portion 622 are in contact with each other on the circumferential center line of the teeth 42. Thereby, each division | segmentation core 40 can be more accurately positioned with respect to the metal core part 811. FIG.

  Further, as shown in FIG. 9, the first mold 81 has a plurality of mold protrusions 812. The plurality of mold protrusions 812 are provided on the outer peripheral surface of the cored bar 811 at equal intervals in the circumferential direction. Each mold protrusion 812 protrudes radially outward from the outer peripheral surface of the core metal part 811. When the stator 21 is inserted into the first mold 81, the wall protrusion 622 is disposed between the mold protrusions 812 adjacent in the circumferential direction. That is, the mold protrusions 812 and the wall protrusions 622 are alternately arranged in the circumferential direction. In addition, the radially outer surface of each mold protrusion 812 faces the lower inner surface 621 of the lower wall portion 62 in the radial direction. Further, the upper surface of each mold protrusion 812 is in contact with the lower surface 421 of the tooth 42. Accordingly, the stator core 211 is positioned in the axial direction with respect to the first mold 81.

  When the placement of the stator 21 and the circuit board 22 in the first mold 81 is completed, the first mold 81 and the second mold 82 are then combined (step S7). That is, the second mold 82 is approached from the upper side in the axial direction of the first mold 81, and the upper part of the first mold 81 is closed by the second mold 82. As a result, as shown in FIG. 9, an annular cavity 83 centering on the central axis 9 is formed between the first mold 81 and the second mold 82, and the stator 21 and the circuit are formed in the cavity 83. The substrate 22 is accommodated.

  Subsequently, the resin 230 in a fluid state is poured into the cavity 83 (step S8). Here, as shown in FIG. 10, the resin 230 in a fluid state is poured into the cavity 83 from the gate 84 provided in the vicinity of the contact surface between the first mold 81 and the second mold 82. The poured resin 230 spreads around the stator 21 radially inward.

  As described above, the cored bar portion 811 of the first mold 81 is in contact with the insulator 212. For this reason, a radial gap 85 exists between the outer peripheral surface of the cored bar portion 811 and the distal end surface on the radially inner side of the tooth 42. If the resin 230 flows into the gap 85, a thin film of the resin 230 having an unstable film thickness is formed on the tip surface of the tooth 42. For this reason, the gap 85 between the outer peripheral surface of the cored bar 811 and the distal end surface on the radially inner side of the teeth 42 is sealed so that the resin 230 does not flow.

  Specifically, the upper portion of the gap 85 is sealed by the outer peripheral surface of the cored bar portion 811 and the upper inner side surface 611 of the upper wall portion 61 coming into contact with each other. The lower portion of the gap 85 is sealed by contact between the outer peripheral surface of the cored bar portion 811 and the wall protruding portion 622, and contact between the upper surface of the mold protruding portion 812 and the lower surface 421 of the teeth 42. Further, at both side portions of the gap 85 in the circumferential direction, the first end surface 631 of the first side wall portion 63 and the second end surface 641 of the second side wall portion 64 face each other through contact or a slight gap, thereby causing the resin 230. The entry of is suppressed.

  Eventually, as shown in FIG. 11, when the resin 230 in a fluid state spreads in the cavity 83, the resin 230 in the cavity 83 is subsequently cured (step S9). For example, when a thermosetting resin is used, the resin in the cavity 83 is heated to cure the resin. Further, when a thermoplastic resin is used, the resin is cured by cooling the resin in the cavity 83. The resin 230 in the cavity 83 becomes the resin casing 23 by being cured. Further, as the resin 230 is cured, the resin casing 23 is fixed to the stator 21 and the circuit board 22. As a result, a unit having the stator 21, the circuit board 22, and the resin casing 23 is obtained.

  When the curing of the resin 230 is completed, the first mold 81 and the second mold 82 are then separated (step S10). Specifically, by raising the second mold 82, the second mold 82 is pulled away from the first mold 81 and the upper part of the first mold 81 is opened. Thereafter, as shown in FIG. 12, the unit having the stator 21, the circuit board 22, and the resin casing 23 is taken out from the first mold 81 or the second mold 82 (step S11).

<4. Modification>
As mentioned above, although exemplary embodiment of this invention was described, this invention is not limited to said embodiment.

  In the above embodiment, the upper inner surface 611 of the upper wall portion 61 protrudes radially inward from the radially inner tip of the tooth 42. However, the upper inner surface 611 only needs to protrude radially inward from the radially inner tip of the tooth 42 at least in steps S7 to S9 described above. For example, when a thermoplastic resin is used as the material of the insulator 212, the radial position of the upper inner surface 611 and the radial position of the tip on the radially inner side of the teeth 42 are the same in a normal temperature environment. Also good. In that case, when the stator 21 is disposed inside the first mold 81 and the second mold 82, the insulator 212 is thermally expanded by heating the first mold 81 and the second mold 82, The upper inner surface 611 may be protruded radially inward from the radially inner tip of the tooth 42. As a result, the upper inner surface 611 may be in contact with the first mold 81 in the radial direction.

  Further, in the above-described embodiment, the entire upper inner side surface 611 of the upper wall portion 61 protrudes radially inward from the radially inner tip of the tooth 42. However, for example, as shown in FIG. 13, only a portion 611 a of the upper inner side surface 611 may be protruded radially inward from the radially inner tip of the teeth 42. In the example of FIG. 13, the central portion 611 a in the circumferential direction of the upper inner side surface 611 protrudes radially inward from the radially inner tip of the tooth 42. That is, on the circumferential center line of the teeth 42, the upper inner surface 611 protrudes radially inward. In this way, it is possible to suppress the upper wall portion 61 from warping radially inward when the resin casing 23 is molded.

  Moreover, in said embodiment, both the stator and the circuit board were covered with the resin casing. However, the circuit board may be disposed outside the resin casing. For example, the circuit board may be fixed on the upper side in the axial direction of the resin casing after the molding of the resin casing.

  In the above-described embodiment, a so-called inner rotor type motor in which a magnet is disposed on the radially inner side of the stator has been described. However, the motor to which the present invention is applied may be a so-called outer rotor type motor in which a magnet is arranged on the radially outer side of the stator.

  Moreover, in said embodiment, both the upper wall part and lower wall part of the insulator were made to contact the 1st metal mold | die. However, only the upper wall portion of the upper wall portion and the lower wall portion may be brought into contact with the first mold.

  FIG. 14 is a longitudinal sectional view of an example of an outer rotor type motor 1A. A stationary portion 2A of the motor 1A shown in FIG. 14 includes a stator 21A and a resin casing 23A. The teeth 42A of the stator 21A extend radially outward from the core back 41A. The insulator 212A of the stator 21A has an upper wall portion 61A located on the upper side in the axial direction of the teeth 42A. An upper outer surface 611A, which is a radially outer surface of the upper wall portion 61A, projects radially outward from the distal end of the teeth 42A on the radially outer side. When molding the resin casing 23A, the upper outer surface 611A is in radial contact with the inner peripheral surface of the first mold.

  Even in such a configuration, by bringing the upper outer surface 611A of the upper wall portion 61A into contact with the first mold, the plurality of divided cores 40A can be accurately arranged in an annular shape. Further, since the resin insulator 212A is brought into contact with the first mold, damage and deformation of the first mold can be suppressed as compared with the case where the metal teeth 42A are brought into contact with the first mold.

  Moreover, about the detailed shape of each member, you may differ from the shape shown by each figure of this application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

  INDUSTRIAL APPLICABILITY The present invention can be used for a resin casing molding method and a motor that at least partially covers the stator of the motor.

DESCRIPTION OF SYMBOLS 1,1A Motor 2,2A Static part 3 Rotating part 9 Central axis 21,21A Stator 22 Circuit board 23,23A Resin casing 24 Lower bearing part 25 Upper bearing part 31 Shaft 32 Rotor 40, 40A Split core 41, 41A Core back 42 , 42A teeth 51 teeth insulating section 52 wall section 61, 61A upper wall section 62 lower wall section 63 first side wall section 64 second side wall section 81 first mold 82 second mold 83 cavity 84 gate 85 gap 211 211 stator core 212, 212A Insulator 213 Coil 421 Lower surface of teeth 611, 611A Upper inner surface 621 Lower inner surface 622 Wall protruding portion 631 First end surface 641 Second end surface 811 Core metal portion 812 Mold protruding portion

Claims (11)

A method of molding a resin casing that at least partially covers a stator of a motor,
a) preparing a first mold and a second mold in which an annular cavity centering on a central axis extending vertically is formed inside by combining with each other;
b) disposing the stator in the first mold;
c) combining the first mold and the second mold, and placing the stator in the cavity; and
d) pouring a fluid resin into the cavity;
e) obtaining the unit having the stator and the resin casing by curing the resin;
f) separating the first mold and the second mold;
g) removing the unit from the first mold or the second mold;
Have
The stator is
A stator core in which a plurality of magnetic cores having a core back and teeth extending from the core back to one side in the radial direction are arranged in the circumferential direction;
A resin insulator covering at least the teeth;
A coil made of a conductive wire wound around the teeth via the insulator;
Have
The insulator is
A contact surface projecting on one side in the radial direction from the radial tip of the teeth;
A molding method in which, in the steps b) to e), the contact surface comes into contact with the first mold in a radial direction. A method of molding a resin casing that at least partially covers a stator of a motor,
a) preparing a first mold and a second mold in which an annular cavity centering on a central axis extending vertically is formed inside by combining with each other;
b) disposing the stator in the first mold;
c) combining the first mold and the second mold, and placing the stator in the cavity; and
d) pouring a fluid resin into the cavity;
e) obtaining the unit having the stator and the resin casing by curing the resin;
f) separating the first mold and the second mold;
g) removing the unit from the first mold or the second mold;
Have
The stator is
A stator core in which a plurality of magnetic cores having a core back and teeth extending from the core back to one side in the radial direction are arranged in the circumferential direction;
A resin insulator covering at least the teeth;
A coil made of a conductive wire wound around the teeth via the insulator;
Have
The insulator is
Formed of thermoplastic resin,
The radial tip and the radial position of the teeth have the same contact surface,
A molding method in which, in the steps b) to e), the contact surface comes into contact with the first mold in a radial direction. The molding method according to claim 2,
The resin casing is formed of a thermosetting resin,
A molding method in which the stator is heated in step c). A molding method according to any one of claims 1 to 3, wherein
The insulator is
An upper wall located above the teeth;
A lower wall portion located below the teeth;
Have
At least the upper wall has the contact surface,
At least a part of the lower wall portion is located on the other radial side than the tip of the teeth,
The first mold is
A mold protrusion protruding on the other side in the radial direction;
In the steps b) to e), the mold projecting portion is opposed to the lower wall portion in the radial direction and is in contact with the lower surface of the teeth. The molding method according to claim 4,
The lower wall portion is
Having a wall protrusion that protrudes in the radial direction from the radial tip of the teeth,
The said wall protrusion part is a molding method which has the said contact surface. The molding method according to claim 5,
The wall protrusion is located on the circumferential center line of the teeth,
In the steps b) to e), the mold protrusion is a molding method positioned between the wall protrusions adjacent in the circumferential direction. A molding method according to any one of claims 1 to 6,
The insulator is
A first side wall portion located on one side in the circumferential direction of the tip of the teeth;
A second side wall located on the other side in the circumferential direction of the tip of the teeth;
Have
In the steps b) to e), the first side wall portion and the second side wall portion overlap in the radial direction between teeth adjacent in the circumferential direction. The molding method according to claim 7,
The first side wall has a first end face inclined with respect to the radial direction and the circumferential direction,
The second side wall portion has a second end face inclined with respect to the radial direction and the circumferential direction,
In the steps b) to e), the first end surface and the second end surface face each other. A molding method according to any one of claims 1 to 8,
The teeth extend radially inward from the core back,
The contact surface protrudes radially inward from the tip of the tooth,
The first mold has a core metal part extending along the central axis,
In the steps b) to e), the contact surface is in radial contact with the outer peripheral surface of the cored bar portion. A stator,
A resin casing that at least partially covers the stator;
Have
The stator is
A stator core in which a plurality of magnetic cores having a core back and teeth extending from the core back to one side in the radial direction are arranged in the circumferential direction;
A resin insulator covering at least the teeth;
A coil made of a conductive wire wound around the teeth via the insulator;
Have
The insulator is
A motor that protrudes to one side in the radial direction with respect to the radial tip of the teeth, or that has the same radial position as the radial tip of the teeth and further has an exposed surface exposed from the resin casing. The motor according to claim 10,
The insulator is
An upper wall located above the teeth;
A lower wall portion located below the teeth;
Have
At least the upper wall has the exposed surface,
At least a part of the lower wall portion is located on the other radial side than the tip of the teeth,
A motor in which a lower surface of the teeth is exposed from the insulator and the resin casing between the tip of the teeth and the lower wall portion.

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