JP4782083B2 - Motor rotor, motor and air conditioner - Google Patents

Description

  The present invention relates to a rotor for an electric motor in which a resin magnet of a ring-shaped rotor and a resin magnet for position detection are combined apart from each other and integrated with a shaft and a thermoplastic resin. The present invention relates to a method for assembling a child resin magnet with high accuracy.

  Conventional non-printer motors do not cause deterioration of characteristics, such as increased vibration, even if a printed circuit board with electronic components mounted inside is built in the motor, making them smaller, lighter, lower power consumption, and higher quality The main magnetic pole part and the magnetic pole part for the sensor whose diameter is smaller than the inner diameter of the main magnetic pole part are pole-oriented with the same ferrite resin magnet, and the magnetic pole part for the sensor is isotropic. The orientation of the easy magnetization axis of ferrite fine particles, which are magnetic powders, is formed, and the structure of the integrally formed magnet rotor matches the magnetic center of the stator core and the main magnetic pole, thereby suppressing magnetic saturation and chaining. Since the cross magnetic flux becomes a sine wave and becomes an optimum energization phase with respect to the induced voltage phase, an increase in torque ripple or the like is suppressed, and an increase in vibrations in the shaft and rotational directions is suppressed. Further, since the number of parts and the number of processing steps are reduced, the cost can be reduced, and a low-cost, low-vibration, and compact brushless motor can be obtained. In addition, the rotor of such a brushless motor has a main magnetic pole portion made of sintered ferrite polar anisotropic magnet, a magnetic pole portion for sensor made of ferrite sintered isotropic magnet, and a shaft made of heat such as PBT (polybutylene terephthalate). There is also an example in which a plastic resin is integrally molded and solidified (see, for example, Patent Document 1).

  In addition, the rotor structure having the conventional synthetic resin mold structure is simple in structure, and the rotor, the coupling portion, and the cylindrical magnet are firmly coupled, and the ring-shaped thin magnet is not damaged during assembly. In order to provide an inexpensive rotor structure for a rotating electrical machine, a cylindrical magnet, a side plate, and a rotating shaft portion are placed in an injection molding mold, and a synthetic resin for bonding is injected into the mold to form a coupling portion. Thus, the cylindrical magnet, the side plate, and the rotating shaft portion are integrally formed to form a rotor structure (see, for example, Patent Document 2).

In addition, the conventional plastic magnet rotor has a magnetic pole part molded with a polar-oriented plastic magnet and a central axis in order to obtain a plastic magnet rotor that can reduce transmission vibration force and reduce noise at a low price. It has an arranged shaft and radial ribs radially arranged around the shaft, and a cavity penetrating in the axial direction is formed between the ribs, and is molded from a thermoplastic resin softer than a plastic magnet. A connecting part, and the magnetic pole part is coupled to the shaft through the connecting part (see, for example, Patent Document 3).
JP 2000-324785 A JP-A-7-31120 JP 2001-320844 A JP 2003-61279 A JP 2001-275317 A JP-A-62-203539 JP 2002-58186 A Japanese Utility Model Laid-Open No. 5-23784 JP 2003-88059 A JP 2000-184637 A

  In a rotor of an electric motor in which a position detecting resin magnet aligned in parallel with a conventional polar-oriented ring-shaped rotor resin magnet is integrated with a shaft and a thermoplastic resin, the resin magnet of the rotor is molded. Since it is manufactured, the inner and outer diameter dimensions have finished widths depending on molding conditions, materials, environments, and the like. When integrating the rotor resin magnet and the shaft with thermoplastic resin, if the mold structure is to hold the outer diameter of the rotor resin magnet, the finished width and fixing of the outer diameter of the rotor resin magnet is fixed. The clearance for inserting into the side mold, the clearance between the shaft and the shaft insertion part of the mold, etc. are accumulated, and the coaxiality of the outer diameter of the resin magnet of the shaft and rotor deteriorates. Was a factor in vibration.

  The present invention has been made to solve the above-described problems, and is capable of improving productivity and quality. An electric motor rotor, a method for manufacturing an electric motor rotor, and an electric motor rotor resin. It aims at obtaining a molding die, an electric motor, and an air conditioner.

The rotor of the electric motor according to the present invention is an electric motor rotor in which a ring-shaped rotor resin magnet and a position detection magnet are molded integrally with a shaft.
In the inner diameter of one end face of the ring-shaped rotor resin magnet , a plurality of tapered cutouts for positioning the rotor resin magnet at the time of resin molding are provided for each magnetic pole .
The step where the end surface of the rotor resin magnet protrudes from the die mating surface of the fixed mold during resin molding is greater than the gap between the end surface of the rotor resin magnet and the installation surface of the rotor resin magnet of the fixed mold With large mold dimensions,
The mold mating surface between the holding surface of the position detection resin magnet of the movable mold and the fixed mold of the movable mold with respect to the distance between the end surface of the position detection resin magnet and the end surface of the rotor resin magnet And mold dimensions with a small distance from
At the time of integral molding with the shaft, the resin is blocked by the end surface of the position detection resin magnet and the both end surfaces of the resin magnet of the rotor .

In the rotor of the electric motor according to the present invention, the step in which the end surface of the rotor resin magnet protrudes from the die mating surface of the fixed side mold during resin molding is such that the end surface of the rotor resin magnet and the rotor of the fixed side mold The mold size is larger than the gap between the resin magnet installation surface and the distance between the end surface of the position detection resin magnet and the end surface of the rotor resin magnet. The distance between the holding surface and the mold-mating surface of the movable-side mold on the fixed-side mold has a small mold size, and the end face that exposes the position detection resin magnet and the rotor resin when integrally molded with the shaft Since the resin is blocked at both end faces of the magnet, it is possible to suppress the occurrence of burrs on the outer periphery of the resin magnet for position detection and the resin magnet of the rotor, thereby improving the quality.

Embodiment 1 FIG.
1 to 4 are diagrams showing the first embodiment, FIG. 1 is a diagram showing a rotor of an electric motor, FIG. 2 is a diagram showing a resin magnet of the rotor, and FIG. 3 is a mold for resin molding of the rotor. FIG. 4 is a diagram showing a manufacturing flow of the rotor of the electric motor.

  As shown in FIG. 1, a position detecting resin magnet 3 is assembled to a ring-shaped rotor resin magnet 6 at a predetermined distance from the end surface of the resin magnet 6 of the rotor, and the shaft 1 to which the knurled 2 is applied. It is molded and integrated with a thermoplastic resin 9. The position detecting resin magnet 3 provided with the step 5 is attached to the rotor resin magnet 6 by the attachment foot 4. Both end surfaces of the resin 9 on the outer periphery of the shaft 1 become bearing installation surfaces 10. As will be described in detail later, the gate 11 at the time of integral molding with the shaft 1 is arranged in a convex shape further inside than the inner diameter of the resin magnet 6 of the rotor. In addition, a thin skin 12 is formed on the outer periphery of the position detecting resin magnet 3 during integral molding with the shaft 1.

  Here, the resin magnet 6 of the rotor is formed by mixing a thermoplastic material with a magnetic material. As shown in FIG. 2, the rotor magnet magnet 6 is pole-oriented and has a notch 8 tapered from one end face to the inner diameter of the magnetic pole. And a pedestal portion 13 for placing the position detecting resin magnet 3 on the end surface opposite to the end surface having the notch 8.

  The position detecting resin magnet 3 can be separated from the end surface of the rotor resin magnet 6 by the pedestal portion 13, and the thickness of the position detecting resin magnet 3 can be minimized and arranged at an arbitrary position. Costs can be reduced by filling a thermoplastic resin that is cheaper than a resin magnet. Moreover, the material of the position detection resin magnet 3 can be made inexpensive and different from the resin magnet 6 of the rotor.

  The pedestal portion 13 is provided with a mounting hole into which the mounting foot 4 provided in the position detecting resin magnet 3 is fitted, and serves as a detent when the pedestal portion 13 is assembled to the resin magnet 6 of the rotor. Further, the positioning projection 7 is provided on the pedestal portion 13 so that the positioning stop portion 24 of the movable mold 16 is positioned during resin molding with the shaft 1.

  The inner diameter of the resin magnet 6 of the ring-shaped rotor is provided with anti-rotation projections 14 at a plurality of locations, and is embedded in the resin molding with the shaft 1 so that the rotational torque is applied to the shaft 1 by the anti-rotation projections 14. Communicated.

  In addition, at the time of integral molding with the shaft 1, a thin skin 12 is also formed on the outer periphery of the position detection resin magnet 3, corresponding to variations in the outer diameter of the position detection resin magnet 3. Since the resin is blocked by the protruding end face and both end faces of the rotor resin magnet 6, it is possible to suppress the occurrence of burrs on the outer periphery of the position detection resin magnet 3 and the rotor resin magnet 6, thereby improving the quality. ing.

  Further, by arranging the gate 11 at the time of integral molding with the shaft 1 in a convex shape further inside than the inner diameter of the resin magnet 6 of the rotor, the concentration of pressure is eased and the resin can be easily filled. The convex portion can also be used for positioning.

  The manufacturing method of the rotor of the electric motor will be briefly described with reference to the manufacturing flow of FIG. After the rotor resin magnet 6 and the position detection resin magnet 3 are formed, each is demagnetized, and the position detection resin magnet 3 is assembled to the rotor resin magnet 6. On the other hand, the shaft 1 is processed into a predetermined shape. The resin magnet 6 of the rotor to which the shaft 1 and the position detection resin magnet 3 are assembled is set in a mold, and a thermoplastic resin such as PBT is molded by injection molding and resin molding. Then, each magnet is magnetized, and the bearings are assembled to complete.

  With reference to FIG. 3, the resin molding die for the rotor will be described. The movable mold 16 includes a mold matching surface 18, a position detection resin magnet pressing surface 19, a shaft insertion portion 23, and a rotation stopper pressing portion 24. The stationary mold 17 includes a mold mating surface 18, a rotor resin magnet insertion portion 20, a rotor resin magnet installation surface 21, a notch holding portion 22, and a shaft insertion portion 23.

  As shown in FIG. 3, a rotor resin magnet 6 having the shaft 1 and position detection resin magnet 3 assembled thereto is set in a mold and integrated by resin molding. Here, the resin magnet 6 for position detection is assembled to the resin magnet 6 of the rotor and is set to the fixed mold 17. 6 notches 8 are fitted.

  At this time, a minute gap is formed between the resin magnet installation surface 21 of the rotor of the fixed mold 17 and the end surface of the resin magnet 6 of the rotor, so that the resin magnet insertion portion 20 and the rotor of the rotor of the fixed mold 17 are rotated. A gap is also formed on the outer diameter of the resin magnet 6. And the level | step difference which the end surface of the resin magnet 6 of a rotor protrudes from the metal mold | die matching surface 18 of the stationary mold 17 is the resin magnet installation surface of the rotor resin magnet 6 and the rotor of the stationary mold 17. The die size is larger than the gap with 21.

  Further, the position detection resin magnet pressing surface 19 of the movable mold 16 and the fixed mold of the movable mold 16 with respect to the distance between the end surface of the position detection resin magnet 3 and the end surface of the resin magnet 6 of the rotor. The distance between the mold 17 and the mold mating surface 18 is small.

  The shaft 1 is inserted into the shaft insertion portion 23 of the fixed mold 17 and the movable mold 16 is closed, so that the end surface of the resin magnet 6 of the rotor is the resin magnet installation surface of the rotor of the fixed mold 17. 21 and the mold mating surface 18 of the movable mold 16 and the position detecting resin magnet 3 are pressed against the position detecting resin magnet pressing surface 19 of the movable mold 16, and the distance from each bearing installation surface 10. Is secured.

  A thermoplastic resin such as PBT is injection-molded to form a rotor. At this time, a part of the notch 8 of the resin magnet 6 of the rotor and the non-rotating projection 14 are embedded in the thermoplastic resin to rotate torque. Thus, the rotational torque of the resin magnet 6 of the rotor is reliably transmitted to the shaft 1. Further, the notch 8 of the rotor resin magnet 6 that appears after resin molding can be used for positioning when magnetizing the magnet.

  Since the resin magnet 6 of the rotor is molded and manufactured, only the coaxiality of the mold to be molded is reflected in the coaxiality between the inner diameter and the outer diameter, but the molding conditions and materials are reflected in the inner diameter and outer diameter dimensions. Depending on the environment, it will have a finished width.

  When the rotor resin magnet 6 and the shaft 1 are integrated with a thermoplastic resin, when the mold structure that holds the outer diameter of the rotor resin magnet 6 is used, the outer diameter of the rotor resin magnet 6 is reduced. The finished width, the gap for insertion into the fixed mold 17, the gap between the shaft 1 and the shaft insertion portion 23 of the mold are accumulated, and the coaxiality between the shaft 1 and the outer diameter of the resin magnet 6 of the rotor deteriorates. However, when assembled in an electric motor, it was a cause of sound and vibration.

  However, in the rotor according to the present embodiment, if the notch holding portion 22 of the fixed mold 17 and the shaft insertion portion 23 are coaxial when the mold is processed, only the gap between the shaft 1 and the shaft insertion portion 23 of the mold is obtained. Is reflected in the coaxiality between the shaft 1 and the outer diameter of the resin magnet 6 of the rotor, and the quality can be improved by improving the coaxiality.

  Further, since a gap can be secured between the outer periphery of the resin magnet 6 of the rotor and the resin magnet insertion portion 20 of the rotor of the fixed mold 17, the rotor resin magnet 6 can be attached to the mold. The set operation is facilitated and productivity can be improved.

  In the above embodiment, both the rotor and the position detection magnet are resin magnets. For example, one or both of the magnets are ferrite sintered magnets, and a buffer having a function of providing a coaxial axis. The component may be assembled to a ferrite sintered magnet.

  Further, a magnet in which a magnetic material is mixed with rubber or elastomer may be used for the resin magnet.

  In addition, it has been shown that notches are provided at multiple locations on the inner diameter of the rotor magnet, and positioning protrusions are provided on the end surface opposite to the notches, but positioning in the rotational direction is removed and the inner diameter is tapered. It is good also as a structure which obtains only a concentricity.

  Further, as shown in FIG. 2, the notch 8 of the resin magnet 6 of the rotor has a positional relationship facing the magnetic pole, but this positional relationship may be changed.

  Further, the position detecting resin magnet 3 may be added to the rotor resin magnet 6 without being a separate part.

  Further, the relationship between the fixed side and the movable side of the mold may be reversed.

  Moreover, although the dimensional relationship between the mold and the resin magnet is mentioned, a part or all of them may be different.

  In the above-described embodiment, when the rotor resin magnet 6 and the shaft 1 are integrated with resin, the notch 8 and the shaft 1 of the inner diameter of the resin magnet 6 of the rotor are positioned with a mold, so that the shaft 1 Since the coaxiality of the outer diameter of the resin magnet 6 of the rotor is improved, the quality of the electric motor can be improved.

  Further, since it is possible to make a large gap between the outer diameter of the resin magnet 6 of the rotor and the resin magnet insertion portion 20 of the mold rotor, the magnet setting work is facilitated, and productivity is improved. The accompanying cost can be reduced.

Embodiment 2. FIG.
FIG. 5 is a diagram showing the second embodiment and is a diagram showing an electric motor.
As shown in FIG. 5, the motor 25 is completed by combining the rotor 25 of the motor to which the bearing 27 of the first embodiment is attached with a mold stator 28 having a position detection sensor 26.

  When assembled in an electric motor, the distance between the bearing installation surface 10 and the position detection resin magnet 3 is manufactured by resin molding, and therefore the accuracy is good. Therefore, the distance between the position detection sensor 26 and the position detection resin magnet 3 is This makes it possible to improve the position detection accuracy and the quality.

Embodiment 3 FIG.
FIG. 6 is a diagram illustrating the third embodiment and is a diagram illustrating the configuration of the air conditioner. As shown in the figure, the air conditioner includes an air conditioner indoor unit 29 and an air conditioner outdoor unit 30, and the air conditioner outdoor unit 30 includes a blower 31.

  The indoor unit 29 of the air conditioner is connected to the outdoor unit 30 of the air conditioner, and has a blower 31 that is driven by the electric motor shown in the second embodiment. It is preferable to use an electric motor capable of suppressing sound and vibration as a blower electric motor which is a main part for an air conditioner.

It is a figure which shows Embodiment 1, and is a figure which shows the rotor of an electric motor. It is a figure which shows Embodiment 1, and is a figure which shows the resin magnet of a rotor. It is a figure which shows Embodiment 1, and is a figure which shows the metal mold | die which performs resin molding of a rotor. It is a figure which shows Embodiment 1 and is a figure which shows the manufacture flow of the rotor of an electric motor. It is a figure which shows Embodiment 2, and is a figure which shows an electric motor. It is a figure which shows Embodiment 3, and is a figure which shows the structure of an air conditioner.

Explanation of symbols

  1 shaft, 2 knurls, 3 position detection resin magnet, 4 mounting feet, 5 steps, 6 rotor resin magnet, 7 positioning protrusion, 8 notch, 9 resin, 10 bearing installation surface, 11 gate, 12 thin skin, 13 Base part, 14 Non-rotating projection, 15 Mounting hole, 16 Movable mold, 17 Fixed mold, 18 Mold mating surface, 19 Position detection resin magnet pressing surface, 20 Rotor resin magnet insertion part, 21 Rotor resin magnet installation surface, 22 Notch holding part, 23 Shaft insertion part, 24 Non-rotating holding part, 25 Motor rotor, 26 Position detection sensor, 27 Bearing, 28 Mold stator, 29 Air conditioner room Machine, 30 outdoor unit of air conditioner, 31 blower.

Claims (3)

In the rotor of an electric motor in which a ring-shaped rotor resin magnet and a position detection magnet are molded integrally with a shaft,
In the inner diameter of one end surface of the ring-shaped rotor resin magnet, a plurality of tapered cutouts for positioning the rotor resin magnet at the time of resin molding are provided for each magnetic pole,
The step where the end surface of the rotor resin magnet protrudes from the die mating surface of the fixed mold during the resin molding is the end surface of the rotor resin magnet and the installation surface of the rotor resin magnet of the fixed mold. with a large die size than the gap between,
With respect to the distance between the end surface of the position detection resin magnet and the end surface of the rotor resin magnet, the holding surface of the position detection resin magnet of the movable mold and the fixed mold of the movable mold The mold dimensions are such that the distance from the mold mating surface is small,
A rotor of an electric motor , wherein the resin is blocked by an end surface of the position detecting resin magnet and both end surfaces of the rotor resin magnet at the time of integral molding with the shaft . Motor, characterized in that billing with the rotor section 1 Symbol placement of the electric motor, with a position detection sensor for detecting a position of the position detection magnet. An air conditioner using the electric motor according to claim 2 as an electric motor for a blower.

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