JP4905534B2 - Mold electric motor - Google Patents

Description

  The present invention relates to an electric motor integrally molded with a thermosetting resin mainly mounted on an electric device.

  Conventionally, this type of electric motor is known in which generation of a weld line is prevented (see, for example, Patent Document 1).

  Hereinafter, the electric motor will be described with reference to FIGS. 3 and 4.

  As shown in the figure, a first protrusion 102a is provided on the lower mold 102 of the mold 101, a second protrusion 102b is provided on the upper end of the first protrusion 102a, and the second protrusion 102b and the upper A gap 107 is formed between the inner surface of the mold 103. In manufacturing the molded motor, the inner surface of the stator 104 formed by attaching the coil 104b to the stator core 104a is fitted to the first convex portion 102a, and the bearing is supported by the second convex portion 102b. The inner peripheral surface of the support member 106 is fitted, and in this state, resin is injected into the cavity 101a from the gate 101b to form the resin layer 108. Thereafter, the rotation shaft 105b of the rotor 105 is inserted into the resin layer 108. The insertion hole 109 to be formed has a configuration of an electric motor formed by machining.

  In addition, there is a motor of this type in which the upper part of the frame is tapered so that bubbles are not trapped (see, for example, Patent Document 2).

  Hereinafter, the electric motor will be described with reference to FIG.

  As shown in the figure, a stator core 111 is covered with an insulator 112 and a winding 113 is wound thereon, and a circuit board 115 on which an electronic component 114 electrically connected to the winding 113 is mounted is attached to the stator 116. The stator 116 and the circuit board 115 are integrally molded with a mold resin 117 made of a thermosetting resin having an electrical insulating property such as an epoxy resin to form a frame. The electric motor has a tapered portion 118 formed on the upper surface side of the frame.

JP-A-5-260708 JP-A-2-250649

  According to such a conventional electric motor, in an electric motor that opens a hole for attachment to a device, a weld is generated around the hole, and a mechanical effect of the hole is caused by the influence of a microvoid generated by low-pressure injection molding. Since the strength is reduced, measures such as increasing the thickness of the mold resin are required, so the curing time of the thermosetting resin in the molding process becomes longer and there is a problem that it cannot be downsized. There is a demand for a molded electric motor that can prevent a reduction in mechanical strength in the mounting hole, reduce the time required for molding the mold resin, and realize downsizing.

  The present invention solves such a conventional problem, and in a molded electric motor that opens holes for attachment to equipment, by increasing the density of the holes, the mechanical strength can be increased, and the mold resin An object of the present invention is to provide a high-quality molded electric motor that can reduce the time required for molding the resin and can be miniaturized.

In order to achieve the above object, the molded motor of the present invention is an electric motor that opens a mounting hole, and a stator coil is wound with a drive coil through an insulator, and has a thermosetting property having electrical insulation. A stator integrally molded and solidified by injection molding with a resin, and a rotor rotatably held facing the stator core; and the hole is cured by the thermosetting resin during molding The molded electric motor has a structure in which the resin density around the hole is increased by opening it so as to extrude before being performed.

  By this means, in the hole part of the stator formed with thermosetting resin, the resin content present in the part forming the hole part is pushed out around the hole part before hardening, thereby reducing the microvoids near the hole part. In addition, the density can be increased, the mechanical strength can be increased, and the thickness of the thermosetting resin does not need to be increased. A molded electric motor is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the mechanical strength of the vicinity of a hole part is high, the time which molding requires can be shortened, size reduction can be implement | achieved, and the mold electric motor with the effect of being able to improve quality can be provided.

Sectional drawing which shows the mold motor in the 1st Embodiment of this invention Sectional drawing which shows the state at the time of mold shaping of the mold electric motor Sectional drawing which shows the molding die used for the manufacturing method of the conventional electric motor Sectional view showing the motor Sectional view showing another conventional electric motor

The present invention is an electric motor that opens a mounting hole, in which a drive coil is wound around a stator core via an insulator, and is integrally molded by injection molding with a thermosetting resin having electrical insulation. A solidified stator and a rotor rotatably held facing the stator core, and the hole is opened so as to be extruded before the thermosetting resin is cured during molding. The molded electric motor is characterized in that the resin density around the hole is increased , and is present in the hole forming portion in the hole portion of the stator formed of the thermosetting resin. By extruding the resin component around the hole before curing, the microvoids near the hole are reduced and the density is increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIGS. 1 and 2, reference numeral 21 denotes a mold motor, which is a drive coil 22 via an insulator 26 formed of an insulating material on a stator core 30 in which thin steel plates such as silicon steel plates having a plurality of slots are laminated. Is wound. Reference numeral 31 denotes a bracket that holds the bearing 36. Reference numeral 23 denotes a magnet rotor formed by integrally orienting a plastic magnet with a shaft 29 while being polar-oriented at the time of injection molding, and is rotatably arranged on the inner peripheral side of the stator core 30. Reference numeral 24 denotes a Hall element that detects the magnetic pole position of the magnet rotor 23, and reference numeral 35 denotes a drive IC that incorporates a switching element that controls energization to the drive coil 22 based on an output signal of the Hall element 24. Reference numeral 34 denotes a printed circuit board on which the Hall element 24, the drive IC 35, and other electronic components are mounted, and is built in the mold motor 21. The stator core 30, the insulator 26, the drive coil 22, and the printed board 34 are integrally molded with a thermosetting resin 32 such as unsaturated polyester to form a jacket 32 a, thereby constituting the stator 25. 37 is a gate for injecting and injecting the thermosetting resin 32 from the molding machine nozzle 38 when molding the outer cover 32a, and 27 is a hole opened for attachment to the equipment. At the timing when the injection of the curable resin 32 is completed and the gate seal is performed, the extrusion pin 39 arranged on the upper mold of the molding die is pushed out by using an extrusion mechanism (not shown) of the molding machine, so that the hole portion is formed. The hole portion 27 is opened and formed so that the thermosetting resin 32 present in the portion forming the portion 27 is extruded around the hole portion 27 while being compressed. Further, a convex portion 33 is formed in the vicinity of the drive IC 35 incorporating a switching element as a heat generating component, and this convex portion 33 is crushed by the push pin 28 in the same manner as the opening of the hole portion 27.

  According to such a molded electric motor 21 of the present invention, the hole 27 is formed by extruding the thermosetting resin 32 present in the portion where the hole 27 is formed around the hole 27 before the resin is cured. With this configuration, the microvoids in the vicinity of the hole 27 can be reduced and the resin density can be increased. Therefore, the mechanical strength is high without low pressure injection molding and without increasing the thickness of the thermosetting resin 32. In addition, there is no occurrence of cracks and the like, and a high-quality molded electric motor can be realized. In addition, since the thickness of the thermosetting resin 32 can be reduced, the time required for molding can be shortened, so that a molded electric motor with high productivity and reduced size can be obtained.

  Further, a convex portion 33 is provided in the vicinity of the drive IC 35 incorporating the switching element that generates heat, and the resin component forming the convex portion 33 is crushed before curing, so that the thermosetting in the vicinity of the heat generating electronic component (drive IC 35). In addition to reducing the microvoids of curable resin and increasing the resin density, the heat conductivity generated by electronic components can be sufficiently dissipated by maintaining the original thermal conductivity of the thermosetting resin even when low-pressure injection molding is performed. A mold motor with higher efficiency and higher output can be realized.

  In the first embodiment, an inner rotation type mold motor in which the rotor arranged on the inner peripheral side of the stator rotates is used. However, an outer rotation type motor in which the rotor arranged on the outer peripheral side of the stator rotates is used. A molded electric motor may be used, and there is no difference in the effect.

  In the first embodiment, the mold motor has a built-in drive circuit. However, a sensorless mold motor without a drive circuit may be used, and there is a difference in the effect of increasing the mechanical strength of the weld portion. Absent.

  In the first embodiment, the configuration is a DC motor in which a permanent magnet is arranged on the rotor. However, an induction motor that does not use a permanent magnet or a reluctance motor may be used, and there is no difference in the operational effect.

  Further, in the first embodiment, after the convex portion 33 is crushed, it is formed to be slightly concave as shown in the figure. However, even if it is formed to be convex, it is formed to be flat. In addition, by providing and crushing the convex portions so as to obtain a sufficient resin density, there is no difference in the function and effect.

  Also, the height of the opening hole and the height of the convex part before crushing can be made the same because it is possible to simplify the structure of the molding die. Can be achieved by changing the cross-sectional area, such as changing the diameter.

  As described above, in an electric motor that opens a hole for mounting, the resin portion existing in the portion forming the hole is pushed around the hole before curing, so that the hole is formed in the vicinity of the hole. In addition to reducing the number of microvoids, the density can be increased, the mechanical strength can be increased, and it is not necessary to increase the thickness of the thermosetting resin, so the time required for molding can be shortened and the size can be reduced. High-quality molded electric motors that can be obtained can be obtained, so they can be mounted on equipment that operates continuously for 24 hours, such as ventilation equipment, used at high temperatures such as fan heaters, used at low temperatures such as refrigeration / refrigeration equipment, air conditioners, etc. It is useful to mount on equipment that requires high durability.

DESCRIPTION OF SYMBOLS 21 Mold motor 22 Drive coil 23 Magnet rotor 24 Hall element 25 Stator 26 Insulator 27 Hole part 28 Extrusion pin 29 Shaft 30 Stator core 31 Bracket 32 Thermosetting resin 32a Jacket | cover 33 Convex part 34 Printed circuit board 35 Drive IC
36 Bearing 37 Gate 38 Molding machine nozzle 39 Extrusion pin

Claims (2)

An electric motor that opens a mounting hole,
A stator core having a plurality of slots;
A drive coil is wound around the stator core via an insulator,
A stator that is integrally molded and solidified by injection molding with a thermosetting resin having electrical insulation;
A rotor held rotatably against the stator core;
The mold electric motor is characterized in that the hole is opened so as to be extruded before the thermosetting resin is cured at the time of molding to increase the resin density around the hole . Winding a drive coil through an insulator around a stator core having a plurality of slots,
This stator iron core is a method of manufacturing a molded electric motor that is integrally molded by injection molding with a thermosetting resin having electrical insulation,
A method of manufacturing a mold electric motor, wherein a hole for attachment is opened by an extrusion pin provided in a molding machine before the thermosetting resin is cured at the time of molding.

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