JP2007325405A - Rotator of inner-rotor motor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a rotator of an inner-rotor motor, which can inexpensively be manufactured and in which a complicated magnetic field can be formed without need of working a magnet. <P>SOLUTION: The method of manufacturing the rotator 34 of the inner-rotor motor 30 has the rotator 34 where the magnets 48 are installed in a rotator core 46. Holes 49 with which magnet materials are filled are formed in the rotator core 46. The hole 49 is filled with the magnet material, and the magnetic material is solidified with which the whole 49 is filled while it is polarized. The magnets 48 and the rotator core 46 are formed to be integrated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotor manufacturing method for an inner rotor type motor and an inner rotor type motor in which a magnet is attached to a rotor core, such as a DC brushless motor.

The inner rotor type motor is configured such that a rotor surrounds a rotor in which a magnet is attached to a rotor core.
The stator is formed by winding a magnet wire around the stator core.

An example of the structure of a rotor of a conventional inner rotor type motor is shown in FIG.
As described above, the rotor 10 is configured by attaching the magnet 12 to the rotor core 11. The rotor core 11 is formed by laminating a number of electromagnetic steel plates in the axial direction of the rotation axis. In the rotor core 11 formed by laminating electromagnetic steel plates, a plurality of insertion holes 13 for inserting the magnets 12 are formed at equal intervals in the circumferential direction, and the magnets 12 are press-fitted into the insertion holes 13. Or the magnet 12 is attached to the stator core 11 by inserting and fixing with an adhesive, and the rotor 10 is obtained (for example, refer patent document 1).

JP 2001-86675 A (FIG. 2 etc.)

In the conventional inner rotor type motor as described above, since the magnet is press-fitted into the insertion hole of the rotor core or attached using an adhesive, high accuracy is required for the size of the magnet, and the magnet is processed. There is a problem that the cost is high and the unit price of the magnet is high.
In addition, since the magnet is fixed by press-fitting or bonding, a process for strength management is necessary so that the magnet does not come off, and there is a problem that the cost is not easily reduced.
Furthermore, since a magnet magnetized in advance is processed and attached to the rotor core, there is a problem that it is difficult to form a complicated magnetic field.

  Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a rotor manufacturing method for an inner rotor type motor that can be manufactured at a low cost without the need to process a magnet and that can form a complex magnetic field. And providing an inner rotor type motor.

According to the rotor manufacturing method of the inner rotor type motor according to the present invention, in the method of manufacturing the rotor of the inner rotor type motor having the rotor in which the magnet is provided on the rotor core, the rotor core has a magnet. A hole filled with material is formed, the magnet material is filled in the hole, and the magnet material filled in the hole is solidified while being magnetized, so that the magnet and the rotor core are integrated. It is characterized by being molded into
By adopting this method, it is not necessary to process an object previously formed as a magnet and attach it to the rotor core. Further, since the magnet and the stator iron core are molded so as to be integrated, it is possible to obtain a rotor having high strength in which the magnet is unlikely to come off. Furthermore, since the magnet is magnetized at the time of molding with the rotor core, it can be easily magnetized even if a complicated magnetic field is required.
Moreover, a plastic molded resin magnet can be used as the magnet material.

According to the inner rotor type motor of the present invention, in the inner rotor type motor having a rotor in which a magnet is provided on the rotor core, the rotor is a rotor core in which a hole filled with a magnet material is formed. And a magnet which is molded and solidified integrally with the rotor core while the magnet material filled in the hole is magnetized.
By adopting this configuration, it is not necessary to process an object previously formed as a magnet and attach it to the rotor core, so that it is possible to save time and effort for processing. Further, since the magnet and the stator iron core are formed so as to be integrated, it is possible to obtain a rotor that is hard to come off and has high strength. Furthermore, since the magnet is magnetized at the time of molding with the rotor core, it can be easily magnetized even if a complicated magnetic field is required.
Further, as the magnet material, a plastic molded resin magnet or the like can be used.
Further, the magnetic body for the rotor position detection sensor may be formed integrally with the rotor. According to this configuration, a separate sensor magnet is not required, and the cost can be reduced by reducing the number of parts. I can plan. Further, since the sensor magnet mounting process can be omitted, the number of work steps can be reduced. Furthermore, since it is attached by integral molding, a certain attachment accuracy can be guaranteed.

  According to the present invention, it is possible to reduce the manufacturing cost because the labor of processing is saved and the number of processes is reduced. Further, even a complicated magnetic field can be easily magnetized. Further, since the mechanical strength can be increased as compared with the case where the magnet is press-fitted or bonded, it is possible to prevent breakage and detachment of the magnet, thereby ensuring safety.

Hereinafter, an example of the inner rotor type motor will be described with reference to the drawings.
The inner rotor type motor in this embodiment is a DC brushless motor, and is used for an air conditioner fan, a water heater, a compressor, or the like.

The configuration of the inner rotor type motor 30 will be described with reference to FIGS.
The inner rotor type motor 30 includes a rotating shaft 32, a rotor 34 attached to the rotating shaft 32 and rotating together with the rotating shaft 32, and a stator 36 surrounding the rotor 34 in order to drive the rotor 34 to rotate. It comprises.
The stator 36 has a coil 39 formed by winding a magnet wire around a stator iron core.
The rotating shaft 32 passes through a center hole 53 provided at the center of the rotor 34 and is rotatably held by bearings 37 and 38. The bearings 37 and 38 are held at the centers of the brackets 41 and 42, respectively.

The rotor 34 in the present embodiment includes a rotor core 46 formed by laminating a plurality of electromagnetic steel plates 44 and a plurality of magnets arranged so as to surround the periphery of the rotary shaft 32 inside the rotor core 46. 48.
The magnet 48 is formed by solidifying a magnet material inside the rotor core 46. Accordingly, each electromagnetic steel sheet 44 is formed with a filling hole 49 for filling the magnet material. A plurality of filling holes 49 are formed at equal intervals in the circumferential direction of the electromagnetic steel sheet 44.

  Further, each electromagnetic steel sheet 44 constituting the rotor core 46 has a protrusion 51 formed on the upper surface and a recess (not shown) into which the protrusion 51 is fitted on the lower surface. When such electromagnetic steel plates 44 are laminated, the protrusions 51 are fitted into the recesses on the lower surface of the electromagnetic steel plates 44 stacked on top of each other, and the stacked electromagnetic steel plates 44 are connected to each other to obtain an integrated laminate. .

In the present embodiment, the magnet 48 is formed of a plastic molded resin magnet.
Plastic molded resin magnets are made of resin agents containing magnetic powder such as ferrite or rare earth metal, and formed by magnetizing the resin agent containing these magnetic powders into a predetermined shape using a mold. Is done. A neodymium bonded magnet in which neodymium, iron, and boron are bonded with a resin agent is also an example of a plastic molded resin magnet.
Moreover, a thermosetting resin or a thermoplastic resin can be used as the resin agent.

Next, a method for manufacturing the inner rotor type motor will be described with reference to FIGS.
First, FIG. 4 illustrates a molding apparatus for carrying out the manufacturing method of the present invention.
The forming device 52 is used to manufacture the rotor 34 in which the rotor core 46 and the magnet 48 are integrated. Specifically, the rotor 34 is formed by integrally molding a resin agent containing magnetic powder together with the rotor core 46.

The molding device 52 has a rotor core 46 (still caulked) between a first die 54 and a second die 55 provided in a press device (not shown) so as to be movable toward and away from each other. Therefore, a loading portion 56 is formed at a plurality of locations where a plurality of electromagnetic steel sheets 44 can be loaded.
The loading unit 56 is provided in the vicinity of the center of the electromagnetic steel sheet 44, a part having a space having a length that is substantially the same as or slightly shorter than the thickness t in the stacking direction of the stored multiple electromagnetic steel sheets 44, and the electromagnetic steel sheet 44. It is provided on the outer peripheral side and includes a portion in which a filling space 57 communicating with the nozzle portion 59 for filling the plastic molding resin magnet into the filling hole 49 is formed.

  The nozzle portion 59 is formed in a funnel shape in which an opening 59a is formed on one end surface of the second mold 55, and the diameter gradually decreases from the opening 59a toward the first mold 54 side. Further, on the mutual contact surfaces of the first mold 54 and the second mold 55, a flow path for circulating a plastic molded resin magnet from the tip portion 59 b having a small diameter of the nozzle portion 59 toward the filling space 57. 60 is formed.

Further, the first die 54 is provided with an extrusion pin 62 for discharging the rotor core 46 after molding from the molding device 52. The push pin 62 is formed with a step portion 63 so that the tip has a small diameter. The small diameter portion enters the center hole 53 formed through the center of the rotor core 46, and the step portion 63 rotates. The peripheral edge of the center hole 53 of the child core 46 can be pressed.
The first mold 54 is provided with an extrusion pin 64 for discharging the plastic molded resin magnet remaining in the flow path 60 after completion of molding.

The first mold 54 is provided with a permanent magnet 66 for magnetization. The plastic molded resin magnet is magnetized by the arrangement direction of the permanent magnet 66.
Furthermore, when a thermosetting resin is used as the resin agent of the plastic molded resin magnet, it is necessary to provide a heater for heating the plastic molded resin magnet (not shown). By providing the heater, the plastic molded resin magnet filled in the rotor core 46 is heated and solidified.
When the magnet material uses a thermoplastic resin, it is not necessary to provide a heater.

Next, the manufacturing method of this invention is demonstrated based on the flowchart of FIG.
First, a predetermined number of electromagnetic steel sheets 44 are stacked (step S100). Each electromagnetic steel plate 44 is previously provided with a filling hole 49 for pouring a plastic molded resin magnet.
The laminated body (rotor core 46) formed by laminating the electromagnetic steel sheets 44 is loaded into the loading portion 56 between the first mold 54 and the second mold 55 of the molding apparatus 52 (step S102). In addition, when loading a laminated body, the 1st metal mold | die 54 and the 2nd metal mold | die 55 of the shaping | molding apparatus 52 are mutually spaced apart, and are in the state of mold opening.

  After loading the laminate, the first mold 54 and the second mold 55 are closed, and pressing is started (step S104). Simultaneously with the start of pressing, a plastic molded resin magnet is injected into the molding apparatus 52 from the nozzle portion 59 of the second mold 55 (step S106). The plastic molded resin magnet injected from the nozzle part 59 is filled into the filling hole 49 of the laminate (rotor core 46) through the flow path 60 and the filling space 57. Here, it is assumed that the plastic molded resin magnet is formed by mixing magnetic powder into a thermosetting resin.

  Then, the laminated body (rotor core 46) in which the plastic molding resin magnet is filled in the filling hole 49 is pressed in the molding device 52, and the plastic molding resin magnet heated by the heater is solidified. The rotor core 46 is integrated, and the magnet material is magnetized by the permanent magnet 66 for magnetization. Further, the protrusion 51 and the recess fitted in the overlapping electromagnetic steel sheets 44 are firmly caulked by pressing (step S108).

  After pressing, the rotor 34 in which the magnet 48 and the rotor core 46 are integrally formed is taken out from the forming device 52, and the manufacture of the rotor 34 is completed (step S110).

  Further, when the rotor position detection sensor magnetic body 67 is formed so as to be integrated with the rotor, a separate sensor magnet is not required, the number of parts can be reduced, and the cost can be reduced, and the sensor magnet mounting process can be omitted. Therefore, the work man-hours can be reduced. Furthermore, a certain mounting accuracy can be guaranteed.

In the above-described embodiment, a plastic molded resin magnet is taken as an example of the magnet material, and the case where a thermosetting resin is used as the resin mixed with the magnetic powder has been described. However, the magnet material is not limited to such a material, and may be one in which magnetic powder is mixed into a thermoplastic resin.
Alternatively, magnetic powder may be mixed in the adhesive and solidified by drying the adhesive.
Further, the magnet material may not be in the form of a fluid, and the powdered magnet material may be solidified by pressing.

  Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. .

It is sectional drawing which shows the whole structure of the inner-rotor type motor concerning this invention. It is a side view of a rotor. It is sectional drawing of the rotor of FIG. It is sectional drawing which shows schematic structure of the shaping | molding apparatus of a rotor. It is a flowchart explaining the manufacturing method of a rotor. It is explanatory drawing explaining the manufacturing method of the conventional rotor.

Explanation of symbols

30 Inner rotor type motor 32 Rotating shaft 34 Rotor 36 Stator 39 Coil 41 Bracket 44 Electrical steel plate 46 Rotor iron core 48 Magnet 49 Filling hole 51 Projection part 52 Forming device 53 Center hole 54 First die 55 Second die 56 Loading section 57 Filling space 59 Nozzle section 60 Flow paths 62, 64 Extrusion pin 63 Step section 66 Permanent magnet 67 Magnetic body for rotor position detection sensor

Claims (5)

In a method of manufacturing a rotor of an inner rotor type motor having a rotor in which a magnet is provided on a rotor core,
A hole filled with a magnet material is formed in the rotor core, and the magnet material is filled in the hole,
A method of manufacturing a rotor for an inner rotor type motor, wherein the magnet material filled in the hole is solidified while being magnetized, and the magnet and the rotor core are formed integrally.   2. The method of manufacturing a rotor for an inner rotor type motor according to claim 1, wherein the magnet material is a plastic molded resin magnet. In the inner rotor type motor having a rotor in which a magnet is provided on the rotor core,
The rotor is
A rotor core with holes filled with magnet material;
An inner rotor type motor comprising: a magnet formed integrally with a rotor core while the magnet material filled in the hole is magnetized and solidified.   4. The inner rotor type motor according to claim 3, wherein the magnet material is a plastic molded resin magnet.   5. The inner rotor type motor according to claim 3, wherein the magnetic body for the rotor position detection sensor is also formed integrally with the rotor.

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