JP4500649B2 - Method for manufacturing electromagnetic member - Google Patents

Description

  The present invention relates to an electromagnetic member manufacturing method and an electromagnetic member. In particular, the present invention relates to a method for manufacturing an electromagnetic member that can easily form a gap between the tips of teeth when obtaining a motor coil having a plurality of teeth.

  In recent years, development of electric vehicles and hybrid vehicles using both a battery and an engine has been progressing. Such an automobile uses a motor to drive the vehicle.

  For example, as shown in FIG. 1, the motor 1 includes a magnet serving as the rotor 10 on the center side and a stator 20 on the outer periphery thereof. The stator 20 includes a core 21 and a coil 23 around which a conducting wire is wound. The core 21 includes a ring-shaped yoke 210 and a plurality of teeth 220 that are integral with the yoke 210 and project toward the inner peripheral side. Each tooth 220 includes a body part 221 around which a conductive wire is wound, and a flange part 222 protruding in a flange shape from the tip of the body part 221, and a gap 230 is formed so that the adjacent flange parts 222 are not in contact with each other. It is formed. Usually, a conductive wire having an insulating coating formed on the surface of a metal wire is used. Further, the motor 1 includes a hall element 310 that detects the rotational position of the rotor 10, and controls switching of the switching element 330 that constitutes the inverter from the control circuit 320 based on position information by the hall element 310. By this switching, the direct current from the direct current power source 340 is converted into a predetermined alternating current and supplied to the motor 1.

  In the motor as described above, generally, a core obtained by punching a magnetic steel sheet into a predetermined shape and laminating the punched plate is used.

  In addition, by placing a coil winding in soft magnetic material powder and molding it with a mold (for example, Patent Document 1), or by placing a coil and insulated ferromagnetic particles in a compression molding die for compression A technique for forming an electron segment (for example, Patent Document 2) has also been proposed.

JP 56-58764 A Special table 2003-507991 gazette

  However, the technique related to the motor coil has a problem that the insulation coating of the conductive wire constituting the coil may be damaged.

  When using a core laminated with electromagnetic steel sheets, it is necessary to use a punched plate of the electromagnetic steel sheet, and burrs are generated on the punched plate, and the insulation coating of the conductor may be damaged by the burrs. In particular, due to the characteristics of the electromagnetic steel sheet material, the cross section of the teeth body portion is not a circle but a rectangle, and the conductor is pressed at the corners, and the insulation coating is easily damaged. In addition, since the cross section of the teeth body is rectangular, there is a problem that the length of the conducting wire is increased.

  On the other hand, in the technique described in Patent Document 1, since the coil is directly embedded in the soft magnetic powder, it is molded between the soft magnetic powder and the coil at the time of compression or extraction from the mold. This can cause friction and damage the insulation of the conductor. In addition, in this configuration, since the coil is embedded in the soft magnetic powder, the magnetic lines generated by the coil form a closed loop in the core, so that the loss as a magnetic circuit is large.

  Further, even in the technique described in Patent Document 2, friction occurs between the ferromagnetic particles insulated during compression and extraction from the mold and the coil, and the insulating coating of the conductor may be damaged. This is the same as the technique of Patent Document 1. Furthermore, it is necessary to form a gap so that the bristle portions of adjacent teeth are not in contact with each other. However, the technique described in Patent Document 2 does not show any specific technique for forming the bristle portions of the teeth with a gap.

  If a core with a gap between teeth is secured by compressing it with a mold using ferromagnetic powder, it is necessary to use a mold with a complicated shape, which may damage the mold. It becomes easy to invite. For example, it is conceivable that an annular protrusion is provided on the inner peripheral side of the mold and the gap is formed by the annular protrusion. In that case, since the annular protrusion protrudes in a direction intersecting the compression direction in the mold, the compressive force acts intensively on the annular protrusion, and it is easy to cause damage around the annular protrusion. .

  Accordingly, a main object of the present invention is to provide a method of manufacturing an electromagnetic member that can easily form a coil in which a conductor is wound around a core without damaging the insulation coating of the conductor.

  Another object of the present invention is to provide a method of manufacturing an electromagnetic member that can easily form a gap between adjacent tooth tips.

  Still another object of the present invention is to provide an electromagnetic member manufacturing method that can manufacture an electromagnetic member without using a complex-shaped mold.

  The present invention achieves the above-mentioned object by using a resin-molded coil when a magnetic powder and a coil are pressure-molded in a mold and using a high-compression moldable member at the time of pressurization.

  That is, the manufacturing method of the electromagnetic member of the present invention includes a step of preparing a coil wound with a conducting wire, a step of forming a resin mold body in which the coil is resin-molded, and the resin mold body is disposed in a mold. A step of obtaining a press body in which the core made of the magnetic powder and the resin mold body are integrated by filling and pressurizing the magnetic powder around the resin mold body. And the said pressurization is performed in the state by which the highly compression moldable member was distribute | arranged in the said metal mold | die, It is characterized by the above-mentioned.

  As described above, by pre-molding a coil molded in advance with a magnetic powder together with a magnetic powder in a mold, the mold resin can prevent direct contact between the conductive wire and the magnetic powder, thereby preventing the conductive wire from being damaged. Usually, since the insulation coating is formed on the conducting wire of the electromagnetic member, damage to the insulation coating of the conducting wire can be prevented by using a pre-molded resin coil.

  In addition, when the core of the motor coil is formed by the method of the present invention as a plurality of segments divided for each tooth, the high compression moldability member is used as a part of the resin mold body or in combination with the resin mold body. When the segments are combined, a gap can be reliably formed between the bristle portions of adjacent teeth.

  In addition, by using a high compression moldability member at the time of pressing to form a press body, without using a complex-shaped mold having a protrusion in the direction crossing the pressing direction, in the direction crossing the pressing direction. A core having a depression can be formed. That is, by this depression, a gap can be formed between the bristle portions of adjacent teeth when a plurality of segments are combined.

  In the above method for manufacturing an electromagnetic member, it is preferable that the high compression moldable member is formed of the same material as the resin of the resin mold body and is molded as a part of the resin mold body. According to this structure, when forming a resin mold body, a high compression moldability member can also be shape | molded simultaneously.

  When producing a motor coil which is a typical electromagnetic member, more specifically, the high compression moldability member is integrally formed with the resin mold body by the following process. First, a process is performed in which a coil is resin-molded to form a resin mold body in which a cylindrical body containing the coil and a protrusion protruding from one end surface of the cylindrical body are integrated. Next, this resin mold body is placed in a mold, and a magnetic powder core and a resin mold body are integrated by pressurizing the resin mold body by filling and pressing the magnetic powder on the upper and lower sides and the inner circumference. The process of obtaining a body is performed. With this series of steps, when a plurality of segments are combined, the gap between the adjacent brim portions of the teeth becomes a position corresponding to the protrusion, and a gap can be formed at a corresponding position of the protrusion.

  On the other hand, in addition to the method of forming the high compression moldability member integrally with the resin mold body as described above, the high compression moldability member may be formed separately from the resin mold body. That is, the high compression moldability member is manufactured separately from the resin mold body, and in the step of obtaining a press body, the resin mold body and the high compression moldability member are arranged in a mold, and a core made of magnetic powder. It is desirable to obtain a press body by integrating the resin mold body and the high compression moldability member. According to this configuration, not only the same material as the resin material of the resin mold body, but also a highly compression moldable member made of a different material can be used. Moreover, since the high compression moldability member is produced separately from the resin mold body, the production conditions can be freely selected without being restricted by the conditions for forming the resin mold body.

  When producing a motor coil which is a typical electromagnetic member, more specifically, the high compression moldable member is molded separately from the resin mold body by the following process. First, the process of forming the resin mold body which consists of a cylindrical body which incorporates a coil by resin-molding a coil is performed. Next, the process of forming the protrusion distribute | arranged to the end surface of a cylindrical body with a highly compression moldable member is performed. Then, the resin mold body and the protrusions are placed in a mold, and the resin mold body and the protrusions are filled with magnetic powder and pressed on the upper and lower sides and the inner periphery of the mold, and the core and the resin mold body are made of magnetic powder. A step of obtaining a press body integrated with the protrusions is performed. Also by this series of steps, when a plurality of segments are combined, the gap between adjacent bristle portions becomes a position corresponding to the protrusion, and a gap can be formed at a corresponding position of the protrusion.

  The highly compressible member is preferably formed as a protrusion on the end surface side of the resin mold body. By forming a highly compressible member as a protrusion on the end face side of the resin mold body, when a plurality of segments are combined, a position between the bristle portions of adjacent teeth can correspond to the protrusion. Therefore, a gap can be formed at a corresponding portion of the protrusion. Typically, the core has a configuration including a yoke portion, teeth that protrude in a direction intersecting with the yoke portion and are arranged on the inner peripheral side of the coil, and a flange portion that constitutes the tip of the teeth. At that time, it is preferable that the high compression moldability member is disposed on the side of the collar portion. A gap can be easily formed between the brim portions of adjacent teeth by arranging the high compression moldable member on the side of the brim portion.

  In the above method for producing an electromagnetic member, it is also desirable to fill the outer periphery of the resin mold body with magnetic powder in the step of obtaining a press body. The press body can be extracted from the mold relatively easily, and the occurrence of cracks in the core can be suppressed.

  Furthermore, in the manufacturing method of said electromagnetic member, it is desirable to provide the process of removing resin of the resin mold body in a press body. By removing this resin, it is possible to pull out the coil conductor terminal from the press body.

  Hereinafter, the present invention will be described in more detail.

〔coil〕
<Conductor wire>
Various conductors such as circular, elliptical, rectangular, and rectangular types can be used as the conducting wire here. Usually, the conducting wire has a configuration in which an insulating coating is applied on a metal wire. As a material of the metal wire, copper, aluminum, copper containing silver, nickel-plated copper and the like are preferable. For the insulation coating, polyurethane, polyester, polyamide, ester imide, amide imide, epoxy resin or the like is used. Further, it is preferable that the conducting wire has a fusion layer in addition to the insulating coating. By winding and heating a conducting wire having a fusion layer in a spiral shape, the turns can be integrated, and the shape retention of the coil can be improved. For the material of the fusion layer, polyvinyl butyral, epoxy resin, polyamide resin, and the like are suitable. Heating for melting the fusion layer may be performed after forming the coil and before resin molding. In addition, in order to prevent the variation between the turns, it is possible to temporarily fix a plurality of turns with a tape that can easily peel the coil.

<Coil type>
A spiral coil is formed using the above-described conductive wire. Here, the spiral shape is not limited to a circular shape when viewed from the axial direction, and includes an elliptical shape and a rectangular shape. Moreover, the winding method of the conducting wire may be either aligned winding or random winding. For example, in the case where a rectangular conductive wire is used, as shown in FIGS. 10 (A) and 10 (B), both the edgewise winding coil 23A and the flatwise winding coil 23B can be used. In the case of the edgewise coil 23A, the end of the conducting wire is drawn to the upper and lower ends of the coil. In the case of the flatwise winding coil 23B, it is possible to draw out both ends of the conducting wire to the outer periphery of the coil by folding the flat conducting wire into a double and winding the conducting wire with the folded end as the inner peripheral side. Furthermore, as shown in FIG. 10C, a random winding coil 23C using a round wire can also be used. The random winding coil 23C is easy to wind a conducting wire, and the terminal can be pulled out from any position of the coil.

[Resin mold body]
<Mold resin>
The coil formed in a spiral shape is resin-molded to maintain its shape. As the resin used for the mold, a resin having the following characteristics is suitable. In particular, at least the following (A), (C), and (E) are preferable as the characteristics of the high compression moldability member.

(A) It has a low melting point and can be easily dissolved.
(B) Viscosity at the time of melting is low, and it easily goes around between coil turns.
(C) The friction coefficient is small, and the press body can be easily extracted from the mold.
(D) It is possible to prevent the insulating coating of the coil from being damaged due to contact with the magnetic powder during molding of the press body.
(E) It can be easily removed after forming the press body.

  The melting point of the mold resin is preferably 100 ° C. or less.

  For ease of resin removal, it is preferable to satisfy the condition that the resin temperature after press molding is flexible enough to be scraped out with a spatula or that the resin can be removed by heating with a dryer. is there.

  As the mold resin, at 25 ° C., either a soft resin having a penetration of 1 or more as defined in JIS K 2235-5.4 and a hard resin having a penetration of less than 1 can be used.

  Examples of the soft resin include hydrocarbon wax, fatty acid / higher alcohol wax, amide wax, ester wax and metal soap. Specific examples of soft resins include solid esters composed of higher fatty acids and higher monohydric alcohols, whale wax (hexadecyl palmitate), beeswax (a mixture of serotic acid and palmitate esters), cinna wax, stone wax (paraffin). ), Wood wax and the like. In the case of a soft resin, it is relatively easy to extract the press body from the mold. However, in order to make this extraction easier, it is preferable to fill the outer periphery of the resin mold body, that is, between the resin mold body and the mold with the magnetic powder. By filling the outer periphery of the resin mold body with magnetic powder, the frictional force at the time of extracting the press body can be made uniform over the entire friction surface.

  In the case of a hard resin, although depending on the size of the press body and the composition of the magnetic powder, cracks may occur in the core when the press body is extracted from the mold. In that case, in the step of obtaining the press body, it is desirable to fill the outer periphery of the resin mold body with magnetic powder. Filling the outer periphery of the resin mold body with magnetic powder suppresses the occurrence of cracks in the core when the press body is extracted from the mold. The thickness of the magnetic powder disposed on the outer periphery of the mold body is such that the core can be prevented from cracking and can be easily penetrated and removed in a subsequent process. For example, about 0.05 to 1.0 mm is preferable.

  Furthermore, it is preferable that the resin used for the mold is made of a material different from the insulating coating constituting the conducting wire. Thereby, the mold resin can be easily removed from the coil in a later step.

<Configuration of resin mold body>
The shape of the resin mold body is preferably a cylindrical body that can embed the entire coil with a mold resin. In that case, not only a cylindrical body but also a hollow truncated cone shape having different outer diameters in the axial direction may be used. That is, the inner peripheral hole of the coil is not filled with the mold resin, but is molded while leaving the inner peripheral hole, and is formed into a hollow cylindrical body. The cross-sectional shape of the cylindrical body is preferably circular, but may be non-circular such as a rectangle.

  When integrating a high compression moldability member (protrusion) into the resin mold body, it is also possible to form the high compression moldability member (protrusion) with a mold resin. The high compression moldability member (protrusion) is formed so as to protrude from one end surface of the cylindrical body within a range in which a space between the rib portions of adjacent teeth is secured in the resin mold body. On the other hand, when a high compression moldability member (protrusion) is formed separately from the cylindrical body, the high compression moldability member (protrusion) may be the same resin as the mold resin, or another resin may be used. Good. However, since it is necessary to remove or separate the highly compressible formable member (protrusion) after forming the press body, a material having the same characteristics as the mold resin described above or a structure that can be easily separated is suitable. . In addition, the high compression moldable member (protrusion) may be an annular protrusion in any case where it is integrated with the resin mold or separate from the cylindrical body. By forming the ring shape, it becomes easier to form the high compression moldability member (protrusion).

  When resin molding is performed, it is preferable to reduce the thickness of the mold resin on the inner peripheral side of the coil and increase the thickness of the mold resin on the outer peripheral side of the coil. By reducing the thickness of the mold resin on the inner peripheral side of the coil, the clearance between the core and the coil can be substantially ignored when the core is formed later on the inner periphery of the resin mold body. It is desirable that the outer diameter of the resin mold body is substantially the same as the inner diameter of the mold when the press body is formed in a subsequent process, or the thickness of the magnetic powder on the outer periphery of the resin mold body is made as small as possible. With this configuration, the shape of the coil is not disturbed when the press body is formed.

<Molding method>
The resin mold is preferably a molding method in which a coil is loaded into a mold having a core fitted in the inner peripheral hole of the coil and the resin is injected. According to this molding method, the molten resin is simply poured into the mold and cooled, and no special manufacturing equipment is required.

  When forming a high compression moldability member (protrusion) on a part of the resin mold body, for example, if a mold having a groove suitable for the high compression moldability member (protrusion) is formed on the bottom surface, the resin is injected and molded. Good. It is also possible to place a material different from the mold resin on the protruding part and resin mold the whole. Even when the protrusion is formed separately from the resin mold body, the protrusion material may be formed by injecting the protrusion material into a mold having a mold groove corresponding to the protrusion shape, or the protrusion material may be processed by a method other than molding. Also good.

[Molding of pressed body]
<Magnetic powder>
Any magnetic powder can be applied to the present invention as long as it is a magnetic powder. Of these, soft magnetic materials are preferred. In general, a soft magnetic material is a ferromagnetic material that is magnetized by an external magnetic field and then returns to its original state when the external magnetic field is removed. Usually, a material having a large magnetic permeability μ, in other words, a material having a small coercive force Hc, can be said to be a soft magnetic material. More specifically, pure iron, steel (Fe-N, Fe-C, Fe-P), Fe-Si alloy (silicon iron), Fe-Ni alloy (Permalloy), Fe-Mo- Examples include Ni-based alloys (supermalloy), Fe-Co-based alloys (permendur), Fe-Al-based alloys (Sendust), and MnZn ferrite. In particular, a magnetic powder obtained by coating a soft magnetic powder with an insulating thin film is preferable. By using the powder having such a coating, iron loss in the high frequency region of the obtained electromagnetic member can be suppressed, and magnetic characteristics such as magnetic flux density can be improved. The insulating thin film is preferably made of an oxide-containing material. More specifically, iron phosphate, manganese phosphate, zinc phosphate, calcium phosphate, aluminum phosphate, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide and the like can be mentioned.

  Further, an appropriate amount of lubricant may be added to the magnetic powder. By adding the lubricant, the press body can be more easily extracted from the mold. As the lubricant, for example, fatty acids such as stearic acid and oleic acid can be used. The addition amount of the lubricant is preferably 0.15% by mass or less based on the mixed material with the magnetic powder.

  Further, an appropriate amount of a binder may be added to the magnetic powder. By adding a binder, the strength of the pressed body, particularly the bending strength at high temperatures, can be improved. As the binder, a thermoplastic resin, a thermosetting resin, a non-thermoplastic resin, or the like can be used.

<Press body forming method>
The press body is formed by placing the resin mold body and the magnetic powder in a mold and applying pressure. When the high compression moldability member (projection) is produced separately from the resin mold body, the resin mold body and the high compression moldability member (projection) are arranged in the mold. At that time, for example, the high compression moldability member (protrusion) is disposed so as to abut one end surface of the resin mold body. For forming the press body, for example, it is preferable to use a cylindrical or frustoconical mold and an upper punch and a lower punch that move up and down in the mold inner hole. The cross-sectional shape of the mold is not limited to a circle.

For forming the press body, the warm forming method and the die lubrication method, which are well-known techniques, are used to achieve a higher density and an improved space factor of the press body, leading to improved magnetic properties. The powder temperature during warm forming is preferably 100 to 180 ° C. The pressing conditions depend on the material of the mold resin, the material and particle size of the magnetic powder, the size and shape of the object to be pressed, and the pressure applied when forming the pressed body is preferably 7.0 to 15.0 ton / cm ² .

[Removal of mold resin]
It is desirable to remove the mold resin after molding the press body. By this removal, it is possible to pull out the coil wire terminal. For removing the mold resin, simple means such as simply scraping it out with a spatula or melting it by heating with a dryer is suitable. When removing the mold resin, the annular protrusion is also removed.

[Specific application fields]
The electromagnetic member obtained by the method of the present invention has a dust core and a coil arranged in a state wound around the dust core. The pressure-dividing magnetic core is a magnetic core formed by pressurizing powder by the above-described manufacturing method, for example. As a typical form of the powder magnetic core, one having a rod-like or pipe-like body portion and flange portions provided at both ends of the body portion can be given.

  This electromagnetic member can be used in various fields utilizing the action as an electromagnet. For example, it can be used for motor coils, solenoids, electromagnetic valves, electromagnetic switches, and the like.

  As described above, according to the electromagnetic member manufacturing method of the present invention, the following effects can be obtained.

  (1) By pre-molding a resin-molded coil together with magnetic powder in a mold, it is possible to prevent the mold resin from coming into direct contact with the insulation coating of the conductor and the magnetic powder during molding of the press body. Damage can be prevented.

  (2) When the motor coil core is formed by the method of the present invention as a plurality of segments divided for each tooth, the protrusions are provided integrally or in combination with the resin mold body, so that the plurality of segments are combined. A gap can be reliably formed between the bristle portions of the teeth adjacent to each other.

  (3) By forming a press body using a highly compression moldable member, an electromagnetic member having a core with a complicated shape can be formed without using a complicatedly shaped die. In particular, a gap can be reliably formed between the bristle portions of adjacent teeth when a plurality of segments are combined.

  (4) Since the resin mold body and magnetic powder are integrated in the mold to form a pressed body, it is easy to make the core cross-sectional shape circular, and the core shape is difficult to damage the insulation coating of the conductor. It can be easily realized.

  (5) There is no need to go through a complicated process of pre-molding the core and winding a conductor around the core.

  (6) When forming the press body, by filling the outer periphery of the resin mold body with magnetic powder, even when a hard resin is used for the resin mold body, the press body can be extracted from the mold without damaging the core. Can do.

  Embodiments of the present invention will be described below.

(First embodiment)
<Configuration of motor coil>
Here, the method of the present invention will be described by taking as an example a manufacturing method for obtaining the motor coil of the inner rotor type motor shown in FIG. The motor 1 includes a magnet serving as the rotor 10 on the center side and a stator 20 on the outer periphery thereof. The stator 20 serving as a motor coil includes a core 21 and a coil 23 around which a conducting wire is wound. The core 21 includes a ring-shaped yoke 210 and a plurality of teeth 220 that are integral with the yoke 210 and project toward the inner peripheral side. Each tooth 220 includes a body part 221 around which a conductive wire is wound and a flange part 222 protruding in a flange shape from the tip of the body part 221, and a gap 230 is formed so that the adjacent flange parts 222 are not in contact with each other. It is formed. The conductive wire wound around the body portion 221 has an insulating coating formed on a metal wire.

  Such a motor coil is made as a unit segment obtained by dividing the yoke 210 for each tooth 220 as follows. This unit segment includes a yoke portion in which a yoke 210 is divided in the circumferential direction and a tooth 220.

<Preparation of coil>
First, a coil is prepared. Here, an edgewise coil is used in which a conductive wire provided with a polyurethane insulating coating is spirally wound on a flat copper wire having a rectangular cross section and formed into a truncated cone shape. The conducting wire is formed of a flat copper wire having a larger thickness and a smaller width toward the smaller diameter side of the truncated cone, and a smaller thickness and a larger width toward the larger diameter side. With this configuration, it is possible to form a coil corresponding to a shape having a smaller width (circumferential length) on the inner peripheral side of the stator and a larger width on the outer peripheral side, and the space factor can be increased. In addition, by making the cross-sectional areas of the conductors substantially the same on the inner peripheral side and the outer peripheral side of the stator, the same current can be flowed over the entire length of the conductive wires.

<Formation of resin mold body>
Next, the coil is resin-molded (see FIG. 2). Here, a mold 30 having a bottomed container shape with an open top, a rod-shaped core 31 at the center, and a frustoconical resin injection hole is used. Here, a mold 30 having a circular groove 32 on the outer peripheral side of the mold bottom is used. This circular groove 32 is for forming an annular protrusion 51 (high compression moldability member) to be described later. By using a resin mold body 50 having an annular protrusion 51, a gap is formed between adjacent teeth brim parts. Form. The prepared coil 23 is fitted on the outer periphery of the core 31. The outer diameter of the core 31 is slightly smaller than the inner diameter of the coil 23, and the outer diameter of the coil 23 is configured to be slightly smaller than the outer diameter of the resin injection hole.

  Subsequently, molten resin 40 is poured into the mold. At this time, the mold 30 does not have a lid, and the molten resin surface remains in a natural surface state. As the resin 40, paraffin wax 125 manufactured by Nippon Seiwa Co., Ltd. was used. This resin has a penetration of 1 or more as defined in JIS K 2235-5.4 at 25 ° C.

  After the molten resin is cured, the resin mold body 50 is extracted from the mold. As a result, as shown in FIG. 3A, a resin molded body 50 in which the coil 23 is embedded in the resin 40 having a hollow truncated cone can be obtained. The resin mold body 50 is formed in a shape in which an annular protrusion 51 protrudes from the end surface on the small diameter side. In addition, as shown in FIG. 3 (B), a frustoconical resin mold body 50 and a ring-shaped annular projection 51 are prepared separately, and the resin mold body 50 and the ring shape are formed during the molding of a press body described later. The protrusion 51 may be housed in a mold.

<Molding of pressed body>
Next, a press body is formed. For forming the press body, as shown in FIG. 4, a die 60 having a filling portion in which a circular hole having a large diameter is opened in the upper portion and a circular hole having a small diameter is opened in the lower portion and the intermediate portion is formed in a truncated cone shape. And upper and lower punches 61 and 62 that pressurize the filling portion from above and below. Here, an upper punch 61 and a lower punch 62 having a curved pressure contact surface recessed upward are used.

  First, the lower punch 62 is positioned in the mold 60, and the resin mold body 50 in which the annular protrusions 51 are integrated is disposed. Since the outer diameter of the resin mold body 50 is substantially the same as the inner diameter of the mold 60, the resin mold body 50 (coil) is arranged coaxially with the mold 60. The magnetic powder 70 is filled inside the resin mold body 50. At that time, the magnetic powder 70 is sufficiently filled also on the inner peripheral side of the annular protrusion 51. Since the magnetic powder 70 is not filled in the portion where the annular protrusion 51 is located, this portion becomes a gap between the flange portions when the stator is manufactured. Further, as shown in FIG. 4, the magnetic powder 70 is also filled in the upper part of the resin mold body 50. Here, as magnetic powder 70, Sweden: Hoganas: somaloy500 was used. The somaloy 500 is a magnetic powder having a soft magnetic powder having a phosphate insulating coating.

  When the resin mold body 50 and the annular protrusion 51 are individually manufactured, the annular protrusion 51 is first disposed on the lower punch 62, and the magnetic powder 70 is filled in the protrusion. Next, the resin mold body 50 is disposed on the annular protrusion 51 and the resin powder body 50 is also filled with the magnetic powder 70. Furthermore, the magnetic powder 70 may be disposed on the resin mold 50 as well.

When the magnetic powder 70 is filled, the upper punch 61 is lowered, and the object to be pressurized in the mold is compressed at room temperature with the lower punch 62. The applied pressure was 9 ton / cm ² . The density of the obtained segment was 7.5 g / cm ³ .

  After the pressurization is completed, the upper punch 61 is pulled up and the lower punch 62 is pushed up, whereby the press body 80 is extracted from the mold 60. In the obtained press body 80, the teeth in which the magnetic powder is compression-molded and the resin mold body 50 are integrated.

<Removal of mold resin>
The mold resin 40 is removed from the press body 80 obtained. Here, the mold resin 40 was removed by scraping it out with a spatula. At this time, the annular protrusion 51 is also removed. By removing the resin 40, the coil 23 embedded in the resin is exposed and a motor coil segment is obtained.

  A plurality of segments are produced in the same manner, and the segments are integrated in parallel to form a stator. For example, as shown in FIG. 5, when a plurality of segments are integrated in parallel, the portion that becomes the collar portion 222 is formed by a ring-shaped protrusion so as to have a diameter smaller than the inner diameter of the resin filling hole of the mold. A gap 230 is formed between the flange portions, and interference between the flange portions 222 is avoided. In this figure, only a part of the stator 20 formed in an annular shape is shown.

<Insulation coating damage>
The appearance of the insulating coating was inspected for the resulting motor coil conductor. As a result, no damage was observed, and it was confirmed that the molding resin suppressed the coil from coming into direct contact with the magnetic powder at the time of molding the press body, and damage to the insulating coating could be avoided.

<Modification 1>
In addition, the outer diameter of the resin mold body may be slightly smaller than the inner diameter of the mold forming the press body, and the outer periphery of the resin mold body may be filled with magnetic powder. The thickness of the magnetic powder disposed on the outer periphery of the resin mold was 0.05 mm. Filling the outer periphery of the resin mold body with magnetic powder can suppress the occurrence of cracks in the core when the press body is extracted from the mold.

<Modification 2>
In addition, the press body shown in FIG. 6 (B) may be manufactured using the resin mold body 50 shown in FIG. 6 (A). In this modified example, a protrusion 51 (high compression moldability member) having an inner diameter that is generally smaller on the joining side with the coil 23 and larger on the opposite side is used. When the projection 51 is used, the resin in the projection 51 portion is removed from the final molded body, so that a space can be formed between the coil 23 portion and the collar portion facing the rotor. As a result, the magnetic lines of force passing through the collar can be guided to the rotor side, and the return of the magnetic lines of force to the coil side can be suppressed, so that eddy current loss in the coil copper wire can be suppressed and the efficiency of the motor can be increased.

(Second Embodiment)
Next, an embodiment in which the motor coil of the outer rotor type motor is produced by the method of the present invention will be described. In the first embodiment, when the truncated cone-shaped resin mold body 50 is formed, the annular protrusion 51 is integrally formed on the end surface on the small diameter side of the truncated cone. In this example, as shown in FIG. In addition, an annular protrusion 51 (high compression moldability member) is integrally formed on the end surface on the large-diameter side of the truncated cone shape. At that time, a lid having a circular groove corresponding to the annular protrusion is used for a mold for producing the resin mold body 50. Of course, as shown in FIG. 7B, the annular protrusion 51 may be produced separately from the resin mold body 50, and a press body may be formed in combination with the resin mold body.

  The press body 80 is manufactured by arranging the resin mold body in which the annular protrusions are integrated or the resin mold body and the annular protrusions in the mold. At that time, as shown in FIG. 8, upper and lower punches 61 and 62 similar to those of the first embodiment are used. Then, the inside of the resin mold body 50 and the inside of the annular protrusion 51 are filled with the magnetic powder 70 and compression-molded by the upper and lower punches 61 and 62.

  When the press body is manufactured, the resin mold body and the annular protrusion are removed to obtain a stator segment. The specific means for this removal is the same as in the first embodiment.

  A plurality of such segments are produced and integrated in a parallel state to produce the stator 20 of the outer rotor type motor. As shown in FIG. 9, in the stator 20, a flange portion 222 is formed on the outer peripheral side of adjacent segments, and a gap 230 is formed between the adjacent flange portions 222.

  The manufacturing method of the present invention can be used in the field of manufacturing an electromagnetic member composed of a dust core and a coil. The electromagnetic component of the present invention can be used in various fields where the action of an electromagnet is applied, such as a motor coil, a solenoid, a solenoid valve, and an electromagnetic switch.

It is a schematic block diagram of a motor. It is explanatory drawing which shows the preparation process of a resin mold body. (A) is a longitudinal sectional view of a resin mold body in which annular protrusions are integrated, and (B) is a longitudinal sectional view of a resin mold body in which annular protrusions are separately produced. In the press body forming step, (A) is a schematic explanatory view showing the state in the mold before compression, and (B) is a schematic explanatory view showing the state in the mold after compression. It is the partial schematic diagram of the stator of the inner rotor type motor comprised by the segment obtained by this invention method. (A) is a longitudinal cross-sectional view of the resin mold body of the modification 2, (B) is a longitudinal cross-sectional view of a press body using the mold body. (A) is a longitudinal sectional view of a resin mold body in which annular protrusions are integrated, and (B) is a longitudinal sectional view of a resin mold body in which annular protrusions are separately produced. In the press body forming step, (A) is a schematic explanatory view showing the state in the mold before compression, and (B) is a schematic explanatory view showing the state in the mold after compression. It is the partial schematic diagram of the stator of the outer rotor type motor comprised by the segment obtained by the method of this invention. The schematic perspective view of a coil is shown, (A) shows an edgewise winding coil, (B) shows a flatwise winding coil, and (C) shows a random winding coil.

Explanation of symbols

1 Motor 10 Rotor 20 Stator 21 Core 210 Yoke
220 Tees 221 Body 222 Brim 230 Gap 23 Coil
23A Edgewise winding coil 23B Flatwise winding coil
23C random winding coil
30 Mold 31 Core 32 Groove
40 resin
50 Resin mold body 51 Protrusion
60 Mold 61 Upper punch 62 Lower punch
70 Magnetic powder 80 Press body
310 Hall element 320 Control circuit 330 Switching element 340 DC power supply

Claims (7)

Preparing a coil wound with a conductive wire;
Forming a resin mold body in which this coil is resin-molded;
The resin mold body is placed in a mold, and the resin mold body is filled with magnetic powder and pressed to obtain a press body in which the core made of the magnetic powder and the resin mold body are integrated. Prepared,
The method for producing an electromagnetic member, wherein the pressurization is performed in a state in which a highly compression moldable member is disposed in the mold.   The method for producing an electromagnetic member according to claim 1, wherein the highly compression moldable member is formed of the same material as the resin of the resin mold body and is molded as a part of the resin mold body. The highly compression moldable member is produced separately from the resin mold body,
In the step of obtaining the press body, the resin mold body and the high compression moldability member are arranged in the mold, and the core made of magnetic powder, the resin mold body and the high compression moldability member are integrated to obtain the press body. The method of manufacturing an electromagnetic member according to claim 1.   The method for manufacturing an electromagnetic member according to claim 1, wherein the highly compressible member is formed as a protrusion on an end surface side of the resin mold body. The core has a yoke portion, teeth that protrude in a direction intersecting the yoke portion and are arranged on the inner peripheral side of the coil, and a flange portion that constitutes the tip of the teeth,
The method for manufacturing an electromagnetic member according to any one of claims 1 to 4, wherein the highly compression moldable member is disposed on a side of the collar portion.   6. The method for producing an electromagnetic member according to claim 1, wherein in the step of obtaining the press body, the outer periphery of the resin mold body is filled with magnetic powder.   Furthermore, the process of removing the resin of the resin mold body in a press body is provided, The manufacturing method of the electromagnetic member in any one of Claims 1-6 characterized by the above-mentioned.

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