JPS582013A - Manufacturing method of molded coil - Google Patents

Abstract

PURPOSE:To increase crack-resistance and cooling efficiency, by providing an air duct mold and a separatable separator between coils, providing a fiber- reinforced layer on these surfaces, molding the whole, and taking out the mold. CONSTITUTION:An air duct mold 6 is provided between coils 1, 2. A separatable separator 8 is provided at a gap 7. A fiber-reinforced layer 9 is provided on the surfaces of separator 8 and mold 6. All is molded. The mold 6 is taken out after hardening. The reinforcement after molding fiber-reinforced layer 3, 4 of coils, an air duct 6', the exterior layer 9 of separator 8, and a fiber-reinforced layer 5 of the coil 2 prevents the coils from cracking in molding resin 13. The separator 8 prevents both coils from cracking in molding resin 13'. The air duct 6' and a partial separator 8 increase the cooling efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to obtain a primary coil-secondary coil integrated molded coil which has excellent crack resistance and cooling efficiency, and is also excellent in mold processing workability.

In conventional molded coils, a secondary coil and a secondary coil are molded separately. In manufacturing this conventional molded coil, two molding dies are required.
In addition, mold processing work was required for each coil, which took a long time. Further, in assembling the molded coils as a transformer, it took a long time to uniformly adjust the air duct gap between the two molded coils.

- One possible way to compensate for the above drawback is to integrally mold the primary coil and secondary coil in one mold, but although this is possible in small transformers for equipment, it is difficult to -A and above), the size of the coil causes a problem in the crack resistance of the molded coil, and the amount of heat generated causes a problem in cooling efficiency, and solving these problems has been a major problem.

The present invention solves the above-mentioned conventional drawbacks by integrally molding the primary and secondary coils.The present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, a primary coil 1 has high-strength fiber layers 3 and 4 provided on the entire inner and outer surfaces, and a secondary coil 2 has a high-strength fiber layer 6 provided on the entire outer surface. Air duct forming members 6 are provided at arbitrary intervals at several locations in the circumferential direction of the coil at positions a certain distance from the surface of each coil, and air duct forming members 6 are provided at arbitrary intervals between the coils 7 (the area surrounded by the dotted line in Fig. 1). As shown in FIG. 2, the moldable separator 8 is provided so that its circumferential ends 8a overlap the air duct forming material 6, or its upper and lower ends 8b reach the end surface of the coil after molding. After providing a high-strength fiber material layer 9 on the outer surface of the air duct forming material 6, the secondary and secondary coils are integrally molded with resin, and after curing, the air duct forming material 6 is extracted and shown in FIGS. 4 and 5. A molded coil 1o having intermittent air ducts 6 in the circumferential direction as shown is obtained. Alternatively, as shown in FIG. 3, the groove forming material 11, 12 is placed in the space 7 of the adduct' forming material 6 so as to be adjacent to the air duct forming material 6, and the distance between the tips in the vertical direction is adjusted from the upper and lower end positions after molding. A releasable separator 8 is placed in the space between the upper and lower grooves at both ends 8 in the circumferential direction. L overlaps the air duct forming material 6, and both ends 8b in the vertical direction overlap the opposing tips of the groove forming moons 11 and 12, and after the primary and secondary coils are integrally molded, the coils are disposed intermittently in the circumferential direction. The air duct 6' and the coil 10 adjacent thereto are obtained.

. In the structure shown in F, the high-strength fiber material layers 3 and 4 wound around the entire inner circumferential surface and outer circumferential surface of the secondary coil 1 serve as the winding frame material of the secondary coil and also as a crack-resistant reinforcing material. This material needs to have sufficient mechanical strength and be compatible with the mold resin 13. If the mold resin 13 is an epoxy type, it is impregnated with an epoxy semi-cured state (B stage) resin. Sheet materials such as glass cloth and polyester cloth are suitable.

After the molded coil 10 is cured, the air duct forming material 6 is
The material to be removed is a releasable material, such as polythiosine and polythiosine-modified reethylene (Teflon).

Suitable materials include nylon or nylon treated with a silicone mold release agent, or metal treated with a silicone mold release agent or coated with Teflon.

Furthermore, the releasable separator 8 shown in FIG.
The purpose is to improve crack resistance by separating the part where the primary coil 1 and the secondary coil 2 are bonded via the molded resin layer (without chemical bonding) and relaxing the stress. be. Therefore, the configuration is such that both ends 8a in the circumferential direction overlap the air duct forming member 6,
Moreover, both ends 8b in the vertical direction reach the upper and lower end surfaces of the coil after molding as shown in FIG. 6, and reliable mold release occurs between the secondary coil side and the secondary coil side. The appropriate overlap width of both ends 8a in the circumferential direction is 6 to 15 mm; if it is less than 5 mm, the mold release effect of the circumferential ends may be impaired;
When it comes to friends, there is a concern that the cooling efficiency will be lowered as will be described later. The material for the mold-release separator 8 must not adhere to the mold resin, and may be polytyphtholated ethylene (TEFO7), polyethylene terephthalate, or a film or silicone rubber with mold-release treatment such as silicone on at least one side. A so-called releasable material such as a sheet is suitable, but the adhesive strength with the mold resin 13 is 150 ffl in length and 20118 in diameter.
omm overlap, adhere this overlap with mold resin 13, and use a material that has a tensile strength of 1 ok or less after curing, the mold release effect is certain, and cracks will not occur in the mold resin layer 13. , the above tensile strength is 10kg
If it exceeds this, cracks may occur in the mold resin layer 13 due to warping.

Furthermore, the same material as the air duct forming material 6 is suitable for the groove forming material 11, 12 located in the circumferential interval 7 between the air duct forming materials 6 shown in FIG. 3 and adjacent to the air duct forming material 6. A releasable separator 8 used together with this groove forming material 11.12
has the purpose and material as shown in Figure 2 above.
It is exactly the same as the rater. The releasable separator 8 has both ends 8& in the circumferential direction overlapping the air duct and the forming material 6 by 5 to 10 degrees as in the separator 8 in FIG. 2, and both ends 8b in the vertical direction have groove forming material 11° as shown in FIG. 120, with 6 to 10 ffllll overlappingly provided at opposing tips. The situation during overlap is the same as in FIG. 2.

The purpose of providing the groove forming materials 11 and 12 is that there is no groove forming material as shown in FIG. is always exposed on the end face of the molded coil, so there is no problem with the characteristics at all, but there is a concern that the appearance may be partially impaired, and the objective is to eliminate this problem.

That is, as mentioned above, due to the use of the groove forming material 11.12, the releasable separator 8 does not reach the end face of the molded coil 10, but ends up overlapping the bottom of the groove 11.12 after molding. Since the grooves 11 and 12 are not exposed on the end face of the molded coil and are adjacent to the air duct 6 in the circumferential direction, it looks as if the air duct 6 is continuously formed over the entire circumference, giving a beautiful appearance.

On the other hand, a method can be considered in which the releasable separator 8 is slid into the air duct 6 and interposed over the entire circumference.In this case, the mold release effect (improving crack resistance effect) is the same as that of the present invention, but the releasable separator 8 Since a mold release opening air layer is generated between the coil and the mold resin, when the heat generated in the coil is radiated to the air duct 6, it becomes a large thermal resistance and the cooling efficiency is significantly reduced. Thermal resistance to heat flow through the insulating layer is proportional to the thickness of the insulating layer, and directly proportional to the thermal conductivity and cross-sectional area of the insulating layer. .211 fJl, constant cross-sectional area, air heat transfer rate 0-025 KC"/m, b, deg
The thermal conductivity of the e-line layer (molding resin) is o, so K
``1/B, b, aeg, when comparing the thermal resistance from the secondary coil 2 to the air duct) 6, when the releasable separator is provided over the entire circumference, the thermal resistance is 2 compared to the present invention.
The cooling efficiency is tripled, which shows the significant drop in cooling efficiency.

Therefore, as in the present invention, providing the releasable separator 8 only in the part where the air duct 6 does not exist increases the cooling efficiency and makes the intervening part of the releasable separator 8 as small as possible, that is, the area of the air duct 6 is 0. Increasing the cooling efficiency increases the cooling efficiency.

The high-strength fibrous material layer 9 wound around the outer periphery of the air duct forming material 6 and the releasable separator 8 and the high-strength fibrous material layer 6 wound around the outer periphery of the secondary coil 2 are all crack-resistant reinforcing materials. As the material, textile materials such as glass cloth and polyester cloth are suitable from the viewpoint of impregnating properties with the molding resin.

After performing the above insulation treatment, one mold is installed all at once, molded with mold resin 13, and after the curing process, the molded coil 1o consisting of the primary and secondary coils is removed from the air duct forming material 6. , has an air duct 6' that is intermittent in the circumferential direction, or has an air duct 6' that is intermittent in the circumferential direction and grooves 11' and 12 adjacent thereto by removing both the air duct forming material 6 and the groove forming material 11, 12. A molded coil 10 as if it had a continuous air duct is obtained. Epoxy resin mixed with an inorganic filler is suitable as the molding resin.

The f-molded coil 1°, which is integrated with the primary and secondary coils and has an air duct 6, obtained according to the present invention has the following characteristics: the high-strength fibrous layer 9 on the outer periphery of the high-strength fibrous material separator 8 on both sides of the primary coil, and the secondary coil. Outer periphery still strong fiber material layer 5
The FRP layering after molding prevents cracks caused by internal stress generated between the coils 1 and 2 and the molded resin 13, while the releasable separator 8 separates the primary coil side and the secondary coil side. is chemically non-adhesive, −
Mold resin layer 1 sandwiched between secondary coil 1 and secondary coil 2
This completely suppresses the occurrence of complex internal stress that occurs in the air duct 3 and prevents the occurrence of cracks, and the cooling efficiency is improved by the air duct 6 and partial separator 8. In terms of the trench manufacturing method, the number of molds and molding steps is halved compared to the conventional method.
The set rL T:, t, and t can still be treated as one coil.J/), which can still be used as a transformer, eliminates the need to adjust the air duct width between the conventional -i upper mold coil and secondary mold coil, which greatly reduces time. possible.

Examples are shown below.

Example 1 A primary coil 1 in which glass cloth layers 3 and 4 impregnated with epoxy semi-hardened resin were wound around the entire inner and outer peripheral surfaces, and a secondary coil 2 in which glass cloth 6 was wound around the entire outer peripheral surface. In between, - 2 from the secondary coil 1, 61 from the secondary coil 2
! Teflon air duct forming materials 6 are provided at four locations in the circumferential direction of the coil at positions H at intervals of 30 HM, and silicone mold release material is placed on the secondary coil side of the four spaced areas 7 (dotted line areas in Figure 1). A separator 8 made of a treated polyethylene nylphthalate film is overlapped with the air duct forming material 6 at both circumferential ends 8&, and its upper and lower ends 8b are provided with a length reaching the end face of the coil after molding, and the separator 8 and air duct are formed. After wrapping the glass cloth 9 around the outer surface of the material 6, the above-mentioned components were put together into one mold, and an acid anhydride-curing epoxy resin filled with quartz powder was used. f I, O, (, A2.
2) Take process #6□3 to obtain a molded coil 1o with integrated primary and secondary coils with four air ducts 6 intermittent in the circumferential direction.

3 Example 2 In Example 1, groove forming members 11 made of Teflon and having a height approximately equal to that of the air duct forming member 6 are placed adjacent to the air duct forming member 6 at four circumferentially spaced portions 7 of the air duct forming member 6. A separator 8 made of polyethylene terephthalate film treated with silicone mold release is placed around the secondary coil side of the space between the upper and lower groove forming members 11 and 12. Both ends 81L in the direction overlap the air duct forming material 6 by 10111111, and both ends 8b in the upper direction overlap the groove forming material 11°12 by 10 mm. To obtain a molded coil 10 that is integrated with a primary and secondary coil and has an appearance as if it had a continuous air duct.

As is clear from the above description, according to the present invention, a molded coil with excellent crack resistance and cooling performance and good productivity can be obtained.

4

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the insulation structure of the molded coil of the present invention, FIG. 2 is a perspective view showing the positional relationship between the air duct forming material and the separator according to the first embodiment of the present invention, and FIG. FIG. 4 is a perspective view showing the positional relationship between the air duct forming material and the Nana S-lender according to the second embodiment of the invention, FIG. 4 is a plan view showing a part of the molded coil according to the invention in cross section, and FIG. FIG. 4 is a sectional view taken along the dotted line A, FIG. 6 is a sectional view taken along the line B--B in FIG. 4, and FIG. 7 is a sectional view taken along the line B-B in FIG. 5 is a cross-sectional view taken along line BB of FIG. 4, %j. 1...-Secondary coil, 2...Secondary coil J
l/, 3,46.9... High strength fiber material layer, 6.
... Air duct forming material, 6' ... Air duct, 7 ... Spacing section, 8 ... Separator, 1o ... Molded coil, 11, 12...
...Groove forming material, 11.12...Groove, 13.
...Mold resin, 13...Mold resin layer. Name of agent: Patent attorney Toshio Nakao and 1 other person Kame 1
Figure 4

Claims (3)

[Claims] (1) When molding the electromagnetic coil with resin, the primary coil has a high-strength fiber layer on the entire inner and outer surfaces, and the secondary coil has a high-strength fiber layer on the entire outer surface. In between, air duct forming materials are provided at arbitrary intervals at positions a certain distance from the surface of each coil and at several locations in the circumferential direction of the coil, and a releasable separator is placed in the spaced portions, and both circumferential ends thereof are made into air duct forming materials. After forming a high-strength fibrous material layer on the outer surface of the separator and the air duct forming layer, the secondary and secondary coils are molded together with resin, and after curing, the air duct forming material is pulled out and A molded coil characterized by forming intermittent air ducts. (2) Groove-forming materials are provided in the space between the air duct-forming materials so as to be adjacent to the air duct-forming materials, with a sufficient distance between their tips in the vertical direction from the upper and lower end positions after molding, and the space between the upper and lower groove-forming materials is A releasable separator is provided so that both ends in the circumferential direction overlap the air duct forming material, and both ends in the -tod direction overlap the opposing tips of the groove forming material, and after molding, an intermittent air duct is formed in the circumferential direction. 2. The molded coil according to claim 1, further comprising a groove formed adjacent to the molded coil. (3) As a releasable separator material, two films with a length of 160 #IJ and a width of 20 mm are stacked for 1oats, and the overlapping margin is bonded with mold resin, and the adhesive strength with the mold resin is tensile bonded after curing. The molded coil according to claim 1 or 2, characterized in that the molded coil has a strength of 10 kg or less.