JPH0697820B2 - Molded motor stator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stator of a molded motor in which a stator core of a small electric motor used for a fan drive source and the like, a winding, and a bracket are integrally molded. Is.

Conventional structure and its problems The general structure of a conventional small electric motor is that the stator iron core is wound and the stator is built-in and held.
It also comprises a bracket for holding the bearing and a rotor supported by the bearing.

However, in the face of various problems such as limitation to miniaturization, shortening of manufacturing process, reduction of noise and vibration, or improvement of quality such as flame retardancy, fixed winding with fixed winding in the above-mentioned small electric motor. A small electric motor is manufactured by integrally molding a child iron core and a bracket for holding a bearing integrally by resin molding.

FIG. 1 shows a conventional schematic configuration diagram including a die for resin molding a wound stator core and a bracket together in a small electric motor to form the stator. is there.

In the figure, 1 is an upper mold, 1a is an upper mold neck portion, 2 is a lower mold,
3 is a mandrel, 3a is a stepped portion of the mandrel 3, 4 is a molding resin, 5 is a bracket, 6 is a stator core, 7 is a runner, and 8 is a winding.

In the mold, a mandrel 3 is incorporated in the lower mold 2 from the upper mold 1 and the lower mold 2 to hold the stator core 6 and further hold the bracket 5.

Now, the resin 4 sent from the runner 7 by an appropriate injection mechanism holds the stator core 6 and solidifies it, and also integrates the bracket 5 to impregnate and protect the winding 8 applied to the stator core 6 at the same time. It itself is reactively cured to form a frame.

In this case, although the property and material of the resin 4 are not limited, a composite material composed of synthetic resin and various fillers is generally used. Recently, due to price and performance,
Increasingly, thermoset composites are being used for coil encapsulation and molding. That is, it is desirable to use a thermosetting resin in view of the thermal life of the electric motor and the mechanical strength of the structure.

In the above-mentioned molding, since the thermosetting resin as described above has a good permeability, it sufficiently penetrates into the gap between the windings 8 and acts as an insulator by itself, which is convenient. However, on the contrary, due to this permeability, it may have an unexpected adverse effect.

To describe this in detail, for example, in FIG. 1, the flange portion 5a of the bracket 5 is sandwiched between the stepped portion 3a of the mandrel 3 and the upper mold neck portion 1a. This bracket 5
Is usually made by press-forming a thin steel plate, but due to its thickness deviation, distortion at the time of pressing, etc., the thickness of the flange portion 5a cannot always be maintained at a constant dimension, and further flatness is ensured. Things are also difficult, and in many cases it undulates indefinitely as shown in FIG.

If there is a plate thickness error or distortion as described above, as shown in FIG. 2 at the time of molding, between the flange portion 5a of the bracket 5 and the stepped portion 3a of the mandrel 3 and the upper die neck portion 1a. A minute gap is formed, and during molding, a part of the resin 4 leaks out from this gap, and as shown in FIG. 3, it becomes a resin burr 9 and enters the bearing housing hole inner surface 5b of the bracket 5. . This resin burr 9 cures during its molding,
This is an obstacle to the subsequent assembly process of inserting the bearing.

Therefore, it is necessary to remove the resin burr 9 with some kind of tool such as a buff or a blade.

This results in a large number of additional man-hours, which is contrary to the above-mentioned aim of reducing the cost, which is the main purpose of resin molding, and results in a great loss of mass productivity.

In addition, the small pieces of burr that have been left behind may enter the inside of the bearing after completion of the motor, which may be a cause of deterioration in quality and performance such as noise and starting failure. On the other hand, for the same reason, a resin burr 9 is also generated on the outer peripheral surface 5c of the bearing housing hole of the bracket 5, and this resin burr 9 drops inside the motor built-in device, for example, the inside of an air conditioner during use of the motor, which also causes noise It becomes a bad factor such as.

In addition, as a method for solving the above-mentioned problem
As shown in No. 6, the upper part of the upper die for holding the bracket and the upper surface of the mandrel are formed with an annular ridge, and when the bracket is held, the ridge is the flange of the bracket. There is also a method to prevent the formation of resin burrs by making it difficult to insert, but with this method, it is necessary to use a metal mold to form a ridge (height of about 0.1 to 0.2 mm) that requires precision on the mold surface. Prevents resin burrs from forming if the die cost becomes expensive, and if the ridges are worn away due to die wear during mass production, or if the ridges are damaged during mold repair Not only the effect is diminished, but in some cases, it may promote the formation of resin burr.

The object of the present invention is to solve the above-mentioned conventional drawbacks, to have all the features of a small electric motor by resin molding, to eliminate waste of steps such as resin burr removal, and to automate the manufacturing thereof. It is intended to provide a stator for a molded motor.

Configuration of the Invention The present invention comprises an annular stator core having a slot, a winding wire to be housed in the slot, and a bracket in which a housing hole for a bearing that rotatably supports a rotor is formed. An annular protrusion that is smaller than the plate thickness is provided on the flange portion, and when the stator core, the winding, and the bracket are integrally molded at the same time by resin molding, the protrusion of the flange portion of the bracket is formed by the molding die. By sandwiching and sealing the portion, molding is performed by preventing resin burrs from being generated and resin from entering the inner diameter side flange surface of the protrusion and the bearing housing hole of the bracket.

Description of Embodiments The present invention will be described in detail with reference to the embodiments shown in FIGS.

In FIGS. 4 to 10, the same reference numerals as those in FIGS. 1 to 3 denote the same parts. 5d is a flange portion 5a of the bracket 5.
The ring-shaped protrusion provided on the, width 1mm ~ 2mm, height 0.1 ~
It is 0.5 mm, which is smaller than the plate thickness.

In FIG. 4, the bracket 5 is inserted into the mandrel 3 and the mold is clamped in the same manner as in FIGS. 1 and 2. At this time, the protrusion 5d of the bracket 5 is clamped by the upper mold neck portion 1a and the stepped portion 3a of the mandrel 3 as shown in FIG. 5, and the flange portion of the bracket 5 is clamped by the mold clamping pressure.
The protruding portion 5d of 5a receives a force to smooth the unevenness,
In this portion, the upper mold 1 and the mandrel 3 are closely contacted. In this way, by applying a force in the direction of crushing the protrusion 5d and holding it, the plate thickness deviation of the bracket 5 and the strain at the time of pressing are absorbed,
The gap between the upper mold neck portion 1a and the stepped portion 3a of the mandrel 3 and the flange portion 5a of the bracket 5 is O due to the protrusion 5d,
Therefore, the molding resin that has penetrated to the outer diameter line of the protrusion 5d of the bracket 5 is prevented from penetrating to the inner diameter side from that, and therefore the resin burr on the inner surface 5b and the outer surface 5c of the bearing housing hole of the bracket 5 is prevented. Is prevented from being generated.

After molding, as shown in FIG. 9 and FIG.
It is possible to obtain a resin burr 9 as shown in the drawing that does not exist or exist, and it is possible to obtain a resin burr that does not need to be removed after molding and that step can be omitted, unlike the conventional one.

The size of the protrusion 5d depends on the plate thickness and material used, and the protrusion
Depending on the diameter of 5d, the width H of the concave portion is about 0.5T to 2T, and the height h of the convex portion is about 0.1T to 0.5T, where T is the plate thickness.
As a result of the experiment, it is in a range where a good effect can be obtained.

11 to 14 show another embodiment of the protrusion 5d,
The same operation as that of the above embodiment is achieved.

Effects of the Invention With the above configuration, the following effects can be obtained as compared with the conventional example.

(1) A bracket-integrated molded product with no resin burr can be obtained.

(2) The process of removing the resin burr is not required, and the production line can be greatly rationalized.

(3) Various quality problems such as noise and starting failure caused by residual resin burr can be solved, and a high quality molded motor can be obtained.

(4) It is possible to solve the quality problem caused by the resin burr dropping on the device with the built-in molded motor.

(5) It is not necessary to form fine protrusions on the mold, and the cost of the mold does not have to be expensive. In addition, it is possible to save the trouble of managing the repair of the mold.

(6) Since the height of the projections and depressions can be regulated by pressing during bracket molding, the bracket position during molding can be accurately regulated by the molding die.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a conventional stator molding process, and FIG. 2 is an enlarged cross-sectional view of a bracket-holding part of a molding die in a molding state of a conventional stator molding process.
FIG. 4 is a cross-sectional view of a stator molded product of a conventional example, FIG. 4 is a cross-sectional view of a main part of a stator according to an embodiment of the present invention in a molded state, and FIG. 5 is bracket holding by a molding die in a stator molded state. FIG. 6 is an enlarged sectional view of a portion, FIG. 6 is a sectional view taken along the line A-O-B in FIG. 7 of the bracket according to the embodiment of the present invention, FIG. 7 is a front view of the bracket, and FIG. 8 is FIG. 9 is an enlarged sectional view of a portion C, FIG. 9 is a plan view of a finished stator molding product according to an embodiment of the present invention, FIG. 10 is a partial sectional view of the same, and FIGS. 11 to 14 show other embodiments. FIG. 1 ... upper mold, 2 ... lower mold, 3 ... mandrel, 4 ... mold resin, 5 ... bracket, 5a ... bracket flange, 5d ... protrusion, 6 ... stator core, 8 ...... Winding.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Ito 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Haruo Takahashi 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Noriyoshi Asada 1006 Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (56) Reference JP 55-160948 (JP, A) JP 55-56462 (JP, A) JP 59-175130 (JP, A) JP-A-50-159672 (JP, A)

Claims (4)

[Claims] 1. A stator core provided with a winding wire, and a bracket press-molded with a bearing hole for rotatably supporting a rotor formed therein. A stator of a molded motor, which is provided with a protrusion that is smaller than the plate thickness of a bracket that can be clamped and deformed by pressing, and that is integrally molded and solidified with a mold resin. 2. The stator of a molded motor according to claim 1, wherein the annular projection provided on the bracket is provided substantially concentrically with the shaft hole accommodating hole of the bracket. 3. The stator of a molded motor according to claim 1, wherein the annular projection provided on the bracket is projected toward the stator core. 4. The stator of a molded motor according to claim 1, wherein the annular protrusion provided on the bracket is projected on both sides of the flange of the bracket.