JP2529171Y2 - Molded motor stator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATIONS The present invention relates to a stator for a molded motor in which a stator core, a winding, and a bracket of a small motor used for a fan drive source and the like are integrally molded. The present invention relates to a resin burr that adheres to a bracket.

2. Description of the Related Art The conventional structure of a conventional small-sized electric motor has a fixed structure in which windings are applied from the viewpoint of miniaturization, shortening of a manufacturing process, reduction of noise and vibration, or improvement of quality such as flame retardancy. A stator and a rotor are formed by integrally molding a child core and a bracket for holding a bearing with a resin mold.

FIG. 3 is a cross-sectional view of the configuration of a mold and a stator when a stator is formed by integrally resin-molding a wound stator core and a bracket in a conventional small motor. . In FIG. 3, 1 is an upper mold, 1a is a neck portion formed on an upper mold, 2 is a lower mold, 3 is a mandrel, 3a
Is a stepped portion of a mandrel, 4 is a frame made of molded resin, 5 is a bracket, 5a is a flange portion of the bracket,
6 is a stator core, 7 is a mold runner, 8 is a winding,
9 is a stator.

In the above-structured mold, the stator 9
In molding, the inner diameter of the stator core 6 is fitted with the mandrel 3, the end face of the stator core 6 is brought into contact with the stepped portion 3 b of the mandrel, and the stator core 6 is held at a predetermined position of the mold. The bracket 5 is fitted to the small diameter portion at the tip, the flange 5a of the bracket 5 abuts the step 3a of the mandrel, and the neck 1a of the upper metal 1 abuts the flange 5a. The core 6 is positioned so that the mold resin does not leak into the inner diameter of the stator core 6 and the inner diameter of the bracket 5.

However, since the bracket is usually formed by pressing a thin steel plate, the thickness of the flange portion cannot always be kept at a constant size due to a thickness error or distortion at the time of pressing. Not only, it is also difficult to secure flatness,
Often it is wavy in an irregular shape. As a result, a small gap is formed between the flange portion of the bracket and the stepped portion of the mandrel and the neck portion of the upper die, and the molding resin leaks out of this gap during molding, and becomes a resin burr and protrudes into the flange portion of the bracket. Molded. The resin burrs easily fall off due to the smooth surface of the flange portion, and these small pieces enter the inside of the bearing after the motor is completed, causing a bad performance factor such as noise and poor starting.

Therefore, there is a problem that a large number of extra steps are required to remove the resin burrs with some tool.

SUMMARY OF THE INVENTION The present invention provides a stator for a molded motor in which a bracket is improved to eliminate the above-mentioned conventional drawbacks and which does not cause resin burrs.

Means for Solving the Problems In order to achieve this object, the present invention provides a method of simultaneously forming a stator core with a winding and a bracket for rotatably supporting a rotor by resin molding.
The surface of the flange portion of the bracket is provided with discontinuous and minute irregularities such as staring.

Function By providing discontinuous and minute irregularities such as staring on the surface of the bracket flange, the flatness of the flange is improved, and when the mold is closed during resin molding, the step between the flange of the bracket and the mandrel It is possible to reduce a minute gap between the attachment portion and the upper die neck portion. Further, when a flat surface having irregularities is compressed, a variation in plate thickness can be more absorbed than when a flat surface having no irregularities is compressed, and the minute gap can be further reduced. Further, since the fine unevenness of the flange portion of the bracket is discontinuous, it does not leak to the outside through the fine unevenness. If the mold resin leaks out of the gap, it enters into the fine irregularities of the flange portion and hardens, so that it does not easily fall off.

Further, the holding force of the mold resin with the bracket is improved by the increase in the area due to the unevenness.

Embodiment Hereinafter, a stator of a molded motor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a bracket according to an embodiment of the present invention.

FIG. 2 is a sectional view of the stator of the molded motor according to one embodiment of the present invention. Components having the same names as those of the conventional example are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 1, the flatness of the flange 10a is improved by discontinuously applying fine irregularities 11 by staring to the flange 10a of the bracket 10 by press working.

In FIG. 2, when the bracket 10 and the stator core 6 are inserted into the mandrel 3, when the mold is clamped, the convex portion of the flange portion 10a of the bracket 10 is compressed and deformed, eliminating the gap between the mold and the flange portion 10a. . In addition, since the fine irregularities 11 due to star formation are discontinuous, the fine irregularities 11
The mold resin 4 does not leak to the outside.

If the thickness of the flange portion 10a of the bracket 10 is small, resin burrs 9 adhere to the flange portion 10a as in the conventional example, as shown in FIG. However, the attached resin burr 9
Enters into the concave portions of the fine irregularities 11 due to the starring and hardens, so that it becomes a thick film and does not easily fall off. In addition, since the surface area of the mold resin 4 is increased due to the fine irregularities 11 due to the starring and the mold resin 4 enters the recesses, the holding force between the bracket 10 and the mold resin 4 is improved, and the idling between the bracket 10 and the mold resin 4 is performed. The torque also improves.

Effect of the Invention As described above, the discontinuity and fine irregularities 11 formed by staring on the flange portion 10b of the bracket 10 eliminate the adhesion of the resin burr 9 and prevent the resin burr 9 from falling off even if it is attached. Removal is not required. It is needless to say that the same effect can be obtained not only by staring but also by other methods by providing discontinuous fine irregularities on the flange portion.

As described above, the stator of the molded motor according to the present invention eliminates the gap between the mold and the flange portion by providing discontinuous and minute irregularities such as starring on the surface of the flange portion of the bracket, thereby preventing leakage of the mold resin. To prevent
The leaked resin will enter the fine irregularities of the flange part and will not easily fall off the flange part, eliminating the need for the process of removing resin burrs, thereby achieving a large rationalization of the production line. is there.

Also, various quality problems such as noise and poor starting caused by the resin burr falling off can be solved, and a high quality molded motor can be obtained.

In addition, the holding force between the mold resin and the bracket is improved, and the idling torque between the bracket and the mold resin is also improved. Therefore, it is not necessary to perform a process for improving the idling torque on the bracket, and it is inexpensive. .

[Brief description of the drawings]

FIG. 1 is a perspective view of a bracket according to an embodiment of the present invention,
FIG. 2 is a sectional view of a stator molded product and a mold according to an embodiment of the present invention, and FIG. 3 is a sectional view of a conventional stator molded product and a mold. 1 upper mold, 1a neck part, 2 lower mold, 3 mandrel, 4 mold resin, 6 stator core, 7
... runner, 8 ... winding, 9 ... resin burr, 10 ... bracket, 10a ... bracket flange, 11 ... fine unevenness due to star-strike.

Claims (3)

(57) [Scope of request for utility model registration] 1. A stator for a molded motor, wherein a stator core with a winding and at least one bracket among brackets for rotatably supporting a rotor are integrally molded and solidified with a mold resin. A stator for a molded motor, wherein minute discontinuous irregularities are provided on the surface of the flange portion of the bracket. 2. The stator according to claim 1, wherein the unevenness of the bracket is provided substantially concentrically with the bearing receiving hole of the bracket. 3. The stator for a molded motor according to claim 1, wherein the unevenness of the bracket is provided on both surfaces of a flange portion of the bracket.