JPS624941B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of manufacturing a wire-wound coreless coil. Conventionally, wire-wound coreless coils are made by winding self-welding wires and then temporarily fixing the self-welding wires to each other and between each single coil. This coil is shaped into a predetermined shape such as a cup shape or a flat shape, and is then made into a rigid body integrally with a shaft, a commutator, etc. Integral rigidization can be roughly divided into rigidization of the coil itself, which has been shaped into a predetermined shape, and rigidification between the coil, shaft, and commutator.
A method of simultaneously making the material rigid by resin molding such as transfer molding is often used. The present invention relates to a method of integrally forming a coil itself into a predetermined shape. Conventionally, when winding a wire-wound coreless coil into a predetermined shape, the wire coating is severely damaged due to friction between the self-fused wires forming the coil, resulting in frequent coil layer shorting and disconnection defects. Particularly, parts of the coil that are wound while floating may cause electrical failures such as disconnection during resin molding. Further, when a resin molding method is adopted when the coil is integrated with the shaft and commutator, it is inevitable that some electric wires will be exposed in the coil portion. As described above, the present invention eliminates the partial exposure of the coil to the surface of the molded product, which occurs when the wire-wound coreless coil is made into an integral rigid body by resin molding.
The winding has sufficient reliability in terms of quality by eliminating the cause of electrical defects by buffering the friction between the wires that occurs when shaping and temporarily fixing the wire-wound coreless coil into a predetermined shape. The present invention provides a method for manufacturing a wire-type iron-core coil. That is, the wound self-fusing electric wire is temporarily fixed using an organic solvent solution containing a synthetic resin having re-softening properties. (As a result, a synthetic resin coating film is formed on the surface or inside of the coil.) The method is characterized in that the coil is shaped into a predetermined shape while melting this synthetic resin coating film. The details will be explained below. Fig. 1 is a configuration diagram of a cup motor using a cup type ironless coil, Fig. 2A is a diagram after temporarily fixing the cup type ironless coil which will become the armature of the cup motor, and Fig. 2B is a diagram showing the cup type ironless coil. This is an iron core coil shaped into a predetermined shape. FIG. 3 is a diagram showing a state in which the coil has been shaped into a flat coreless coil. In these figures, 1 is a coreless coil, 1' is a single coil of coreless coil 1, 2 is a commutator, 3 is an armature shaft, 4 is a bearing, 5 is a brush, 6 is a magnet, and 7 is a frame. be. In the above configuration, a manufacturing method thereof will be explained. First, a solution of a synthetic resin in an organic solvent is prepared. The synthetic resin is desirably thermosetting and has excellent adhesion to the wire coating, a melt viscosity of 500 to 2000 cps, and compatibility with the low-pressure molding material used for molding. Further, as the organic solvent, it is preferable to use a ketone, alcohol, chlorine, etc. suitable for solvent bonding the self-bonding electric wire. The organic solvent solution of the synthetic resin should have a resin content of 10 to 40% by weight and a viscosity of 20 to 100 cps to facilitate the temporary fixing work, and to reduce the thickness of the newly formed synthetic resin coating film by temporary fixing. Saga 20
It is desirable that the thickness be ~100μ. After laminating single coils made by winding a predetermined number of self-bonding wires, an organic solvent solution of the above-mentioned synthetic resin is dropped, and the organic solvent is allowed to stand for several minutes to volatilize, thereby temporarily fixing the coreless coil ( Figure 2 A) is obtained.
Incidentally, since the synthetic resin coating film formed here also contributes to the temporary fixing force, even when the organic solvent is dried to the touch, it becomes strong enough for handling. When shaping the temporarily fixed coil into a predetermined shape using a mold, the process is carried out while melting the previously formed synthetic resin coating. The molten synthetic resin coating greatly promotes the lubrication between the wires during shaping, which was insufficient with only the adhesive layer of conventional self-welding wires, thereby significantly reducing the occurrence of electrical defects such as layer shorts and disconnections. Reduce. Furthermore, conventionally, the wires were bonded together by melting and solidifying the fusion layer on the surface of the wire, but since the synthetic resin coating contributes to the adhesive force, a shaped coil (FIG. 2B) with even higher strength can be obtained. Therefore, it can be used in resin molding such as transfer molding without further making the armature winding rigid. In addition to the method of applying the organic solvent solution of the synthetic resin to the coil, other methods such as spraying and dipping can also be used in addition to the above-mentioned dropping method. Next, when resin molding is performed to integrate the armature coil with the shaft and commutator, the coreless coil 1 having the synthetic resin coating is placed in a resin mold and the mold is clamped. In this state, the low-pressure molding material is pressurized and filled into the commutator side coil end portion. The strength of the coil is further improved by the synthetic resin coating, so there is no need to fill the coil with molding material.
Also, the coil will not be deformed during molding. Furthermore, since the coil is sufficiently protected by the synthetic resin coating, the quality is sufficiently reliable. When considering compatibility with the coil, low-pressure epoxy resin molding materials, low-pressure diallyl phthalate resin molding materials, etc. are highly practical as low-pressure molding materials for molding the commutator-side coil end portion. On the other hand, the coil and armature shaft,
Integration with the commutator is not limited to the above-mentioned resin molding, and may be fixed with an adhesive via a plate, for example. Examples will be described below. Example 1 A self-bonding polyurethane insulated wire having a butyral resin fusion layer having a wire diameter of 0.15φ was wound 49 times, and 7 of these were stacked on a winding workpiece. A 40% acetone solution of a synthetic resin consisting of the following components was dropped onto this coil and evaporated to temporarily fix it. Epicote 1001 (Ciel Chemical Products)
………100 parts by weight Resin M (Maruzen Oil Products) ………25 〃 BF ₃ -2 Methylimidazole ………1 〃 The coating film thickness of the above synthetic resin temporarily fixed is
It was 10-70μ. The melting point of this coating is 80-90°C. This coil has an inner diameter of 19.5φ, an outer diameter of 20.8φ, and a height of
It was shaped into a 30.0 cup shape. The mold used for shaping was preheated to 150-170°C. A product with heat rigidity was obtained within 0.5 to 1.0 minutes after shaping. In addition, when 50 coils were tested under the same conditions, there were no layer shorts or wire breaks. Comparative Example 1 The same coil as in Example 1 was temporarily fixed with acetone,
Coil shaping was performed under the same conditions. This coil has insufficient rigidity when hot, and requires extreme care when removing it from the mold. Of the 50 shaped coils, there were 5 layered coils and 6 broken wires.
There were 11 electrically defective products. Example 2 The shaping coil according to the present invention obtained in Example 1 was further
It was cured at 150°C for 2 hours. A commutator and shaft were connected to this coil via the coil terminals to form a cup armature. At this time, the shaft coils were fixed with an epoxy resin adhesive via a 1 mm thick phenol laminate. This armature was used to create a motor as shown in Figure 1. This motor remained undamaged even when a lock current of 30 A/mm ² was applied for 5 hours. Comparative Example 2 The same study as in Example 2 was attempted using the good shaped coil obtained in Comparative Example 1, but this motor
Cannot withstand lock current of 30A/ ^mm2 . Example 3 A commutator bonded to the shaft in advance was connected to the shaped coil according to the present invention obtained in Example 1 via the coil terminal and installed in a mold. Next, a low-pressure epoxy resin molding material (CEL-874B: Hitachi Chemical Co., Ltd.) was pressurized and filled into the coil end portion on the commutator side, thereby forming an armature in which only the coil, armature shaft, and commutator portion were resin-molded. When the thermal shock resistance of five of these armatures was examined under the following conditions, it was found that none of them were normal. (120°C←→-40°C) Repeated 5 times Comparative Example 3 The shaped coil of Comparative Example 1 was used to make a resin molded armature under the same conditions as Example 3, but deformation and cracks in the coil were observed from the beginning. Further, when the thermal shock resistance was examined in the same manner as in Example 3, it was found that the molded resin partially peeled off and cracks were formed, and in particular, the exposed coil was lifted up significantly. Example 4 Approx.
A self-fusing polyesterimide insulated wire having a fusing layer of 10 μm thickness was wound 16 times to obtain a single coil 1', which was then laminated into 23 pieces. This coil contains the following components or 20% of synthetic resin consisting of
MEK (methyl ethyl ketone) solution was dropped, volatilized, and temporarily fixed.

[Table] The thickness of the above synthetic resin coating provided during temporary fixation is 20~
It was 40μ. Compared to those shown in Examples 1 to 3, this coating film is a synthetic resin with film-forming ability, so it is easier to handle and has a higher affinity with wire paints, so it is preferable from the standpoint of the degree of deterioration of the electrical insulation of the wires. Give results. This coil shaping is done by heating the coil with an outer diameter of 85φ.
Figure 3 with a thickness of 1.6mm. Shortly after mold clamping
It was possible to create a coreless coil with good rigidity when hot in 10 seconds. In addition, when 50 coils were tested under the same conditions, there were no electrical defects such as layer shorts or wire breaks. Comparative Example 4 The same coil as in Example 4 was temporarily fixed with MEK, and the coil was shaped under the same conditions. This coil requires 20 seconds or more to be heated with electricity, and its rigidity during heating is insufficient, so great care must be taken when removing it from the mold. Of the 50 shaped coils, there were 4 layered coils. As described above, in the present invention, a synthetic resin coating film is formed on the surface and inside of a coreless coil during shaping and temporary fixing of the coil, and the coil is shaped into a predetermined shape while melting this synthetic resin coating film. It has excellent effects such as almost no occurrence of layer shorts or disconnection defects, and also prevents lifting of the coil that occurs during resin molding during armature manufacture.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a cup motor having a cup-shaped coreless coil in which the manufacturing method of the present invention is carried out;
FIG. 2A is a perspective view of the coil in the final shaped state, B is a perspective view showing the state after shaping, and FIG. 3 is a plan view of the coil shaped into a flat shape in which the manufacturing method of the present invention is carried out. be. 1... Coreless coil, 1'... Single coil.

Claims (1)

[Claims] 1. After applying an organic solvent solution containing a synthetic resin to multiple single coils wrapped with self-fusing electric wires, and drying, the adhesive layer of the self-fusing electric wire is bonded with the solvent and the synthetic resin is formed by volatilization of the organic solvent. By forming a coating film, the self-fusing electric wires and each single coil are temporarily fixed. Next, the synthetic resin coating film is heated and melted using a predetermined mold to shape the coil, and is then completely cured. A method for manufacturing a wire-wound coreless coil, which is characterized by being fixed.