JPH0684657A - Core block for electric appliance and production thereof - Google Patents

Abstract

PURPOSE:To produce a core block having sufficient strength and heat resistance easily without causing crack during production. CONSTITUTION:An element core 7 is placed in a metal mold while being applied with a thermally shrinking PPS fiber woven tape 19 and then it is integrated by means of a thermosetting resin to produce a core block. A spacer cloth 32 is interposed between the upper part of the element core 7 and an upper metal mold 34 at the time of heat treatment of core block.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron core block used in electric equipment and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, there is an electric device using an iron core block such as a reactor as shown in FIG. This is a plurality of leg portions 3 formed by alternately stacking an iron core block 1 having a constant height and spacing pieces 2 and magnetically and structurally mutually between the end portions of these leg portions 3 in the same axial direction. It consists of a yoke part 4 which is also connected to the top. In the iron core block 1 of this reactor, the fringing magnetic flux in the space piece 2 portion is constantly moved in and out from the thickness direction of the radial magnetic plate forming the iron core block 1 so that the eddy current loss is reduced.

In a conventional iron core block 1, as shown in FIG. 9, magnetic plates 5 having the same height (the axial dimension of the legs) and different lengths are arranged in order of size with one end aligned. A plurality of fan-shaped units 6 are radially arranged to form an annular core 7. Then, the circular outer peripheral portion is restrained by a band 8 such as a cotton tape to maintain its shape, and is impregnated with a thermosetting resin liquid from below to be thermoset to be integrated into a radial core block 1.

However, in the above-mentioned conventional method, the impregnating resin that has penetrated into the gaps between the magnetic plates 5 shrinks during gelling or hardening during the heating process, and contracts at the weakest point of the steel plate bonding portion as shown in FIG. A crack 9 may occur. If such cracks 9 occur, not only will large noise be generated by the magnetic flux passing through the iron core block 1, but also the strength of the iron core block will be significantly weakened.

Therefore, as shown in FIG. 11, a resin-impregnated annular core 7 is wrapped around with a resin-impregnated glass binding tape 10 and a heat-shrinkable tape 11 which are wound several times alternately and tightened. . Then, they are heated to be integrated, but during the heating process, the core material 7
The resin impregnated in the resin begins to harden, and then the heat shrink tape 11
The respective materials are selected so that the resin of the glass bind tape 10 begins to harden and finally the resin of the core material, the heat shrinkable tape 11, and the glass bind tape 10 finish shrink and harden in this order.

With this structure, first, when the resin of the core material 7 is cured and shrunk, first the heat shrink tape 1 is formed.
1 contracts and compresses the core 7 through the glass binding tape 10 to apply a force toward the center of each magnetic plate 5 so that the magnetic plate 5 can easily follow the contraction of the resin and cracks Try to prevent it. At this time, glass bind tape 1
Since 0 has a smaller shrinkage amount than the heat shrink tape 11 on the outside thereof, the glass bind tape 10 is the heat shrink tape 11
Between the tape 11 and the core 7 is cured while being bent in a wavy shape to maintain the mechanical strength of the core block 1.

As another conventional example, Japanese Patent Publication No. 3-52203
12 and 13 described in the publication. This is manufactured by using a mold 12 having an annular molding portion as shown in FIG. That is, a sheet-shaped fiber base material 13 having a resin impregnating property such as glass fiber is placed in the inner surface and the outer surface of the annular element core 7 in the mold 12 so as to face the body. Next, the magnetic plates 5 are radially arranged in the die 12, and the annular core 7 and the fiber base 13 formed in the die 12 are impregnated with a thermosetting resin and cured.

When cooled after the impregnation and curing, as shown in FIG. 13, the fiber base material 13 existing on the outer periphery of the core 7 within the die 12 is formed.
Since the resin-impregnated and solidified fiber layer 14 is first cooled and shrunk, a stress σ ₂ is applied to the outer periphery of the core 7 in the radial direction toward the center. When the core 7 is further cooled, the magnetic plate 5
The resin layer between them contracts, and the tensile stress σ ₁
However, the stress σ ₂ tightens the outer periphery of the core 7 to cancel the internal stress of the resin layer,
Prevent the iron core block 1 from cracking.

Further, the fiber layer 14a on the inner peripheral side cushions the core plate 12a in the center of the die 12 when the magnetic plate 5 moves in the radial direction toward the center due to the hoop stress σ _2. To prevent cracks occurring near the inner circumference.

[0010]

First, in the means for forming the iron core block by alternately winding the glass bind tape 10 and the heat shrink tape 11 around the element core 7 shown in FIG. 11 described above, the heat shrink tape is used. The shrinkage force of 11 is relaxed by the glass bind tape 10, and it is difficult to act as a tightening force of the radial core material core 7. In addition, since it does not bend even if it is semi-cured as much as the strong glass bind tape 10, only weak glass bind tape 10 can be used to bend and cure like this conventional example, and strong tightening cannot be performed. There was a problem that it was not possible to make an iron core block with sufficient strength.

Further, in the above-mentioned first conventional means, in the heat treatment step, the resin liquid in the annular core is first cured, then the heat shrink tape is shrunk, and finally the glass bind tape 1
The material must be chosen so that 0 can be cured. By the way, generally, in the resin without filler, the lower the thermosetting temperature is, the lower the heat resistance is. Therefore, it is not possible to obtain an iron core block having excellent heat deterioration resistance. There is a problem that it is not possible to make an iron core block that becomes hot during use.

Secondly, in the means for forming an iron core block by using the die and the fiber base material 13 described in Japanese Patent Publication No. 3-52203 disclosed in FIGS. When the base iron core 7 is impregnated with resin and cured and then cooled,
The resin-impregnated and solidified fiber layer wound around the outer circumference of the core iron 7 in the die 12 should be first cooled and shrunk so that a radial stress σ ₂ toward the center of the annular core is applied. I won't. However, since the iron core block generally has a disk shape having an outer diameter larger than its thickness, it is easily cooled from the flat side having a large heat radiation area, and the resin-impregnated and solidified fiber layer 14 wound around the annular element core 7 is There is a problem that it is difficult to manufacture a good core block because it is difficult to shrink by cooling.

In view of the above points, the present invention facilitates the work of wrapping the tape around the outer circumference of the annular core, and when the resin is impregnated and heat-cured, the force in the radiation direction toward the center of the core is sufficiently strong. To prevent the core block from cracking, the completed core block has sufficient mechanical strength, the core block has good heat resistance, can withstand the conditions of high temperature during use, and is easy to manufacture. An object of the present invention is to newly provide an iron core block for electric equipment and a method for manufacturing the same.

[0014]

The iron core block for electric equipment according to the present invention is a heat-shrinkable PPS fiber woven fabric having a mechanical strength equal to or higher than that of a glass bind tape on the outer peripheral portion of a raw iron core in which magnetic plates are radially arranged. It is characterized in that the wound core of the tape is housed in a mold and is integrated with a thermosetting resin by a vacuum casting method or an impregnation method to form an iron core block.

According to the method of manufacturing an iron core block for electric equipment of the present invention, a core of which magnetic plates are radially arranged is wrapped with a heat-shrinkable PPS fiber woven tape around the outer periphery of the core, and the core is inserted into the mold to form the core. The core block is manufactured by integrating with a thermosetting resin by a vacuum casting method with a release cloth interposed between the upper surface and the upper die.

[0016]

In the iron core block for electric equipment of the present invention, the heat-shrinkable PPS fiber woven tape heat-shrinks and shrinks and hardens the resin between the magnetic plates while tightening the raw iron core, so that peeling or cracks occur between the magnetic plates. Is to prevent.

Even if peeling or cracks occur between the magnetic plates, the heat-shrinkable PPS fiber woven tape is firmly tightened from the outer peripheral side of the core to maintain the rigidity of the block-shaped core, thereby reducing noise during use. It is intended to prevent the occurrence and to prevent the strength from decreasing.

According to the method for manufacturing the iron core block for electric equipment of the present invention, when the heat shrinkable PPS fiber woven tape shrinks during vacuum casting heat curing to try to tighten the core portion,
It is intended to easily slip between the upper surface of the core portion and the upper die to eliminate the loss of the tightening force of the tape.

Furthermore, since the upper die can be easily removed from the release cloth portion after the heat curing treatment, the die for molding can be easily disassembled.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an iron core block for electric equipment and a method of manufacturing the same according to the present invention will be described below with reference to FIGS. In addition, in FIG. 1 to FIG.
The same reference numerals are given to the portions corresponding to the conventional example shown in FIG. 13, and detailed description thereof will be omitted. 1 is a vertical sectional view showing a state of manufacturing an iron core block, FIG. 2 is a plan view thereof, and FIG. 3 is a vertical sectional view of the iron core block.
Is an iron core block, 5 is a magnetic plate, 6 is a unit, 7 is an annular element iron core, and 15 is a lower metal mold.

A large-diameter cylindrical outer-diameter mold 16 is assembled on the lower mold 15, and a small-diameter cylindrical inner diameter is concentric with the outer-diameter mold 16 on the central portion of the lower mold 15. The side mold 17 is assembled and the molding mold 18 is framed.

Next, the tape ring 19 is arranged along the inside of the outer diameter side mold 16.

The tape ring 19 is made of P, which is a heat-shrinkable fiber.
It is composed of PS (polyphenylene sulfide) fiber.
The properties of the PPS fiber are that the heat resistance is F type, and the heat shrinkability is 7% shrinkage at 100 ° C., shrinks 0.6 g / d, and generates stress. Furthermore, it does not hydrolyze and has excellent oil resistance.

The tape ring 19 is made of PPS fiber as illustrated in FIGS. 4 is a plan view, FIG. 5 is a sectional view taken along the line EE in FIG. 4, and FIG. 6 is a sectional view taken along the line ROLL in FIG.

In these figures, 20 to 22 are thick warp yarns in which a large number of heat-shrinkable fibers (hereinafter, simply referred to as fibers) are twisted very slightly in order to prevent loosening due to twist return. 23-26 is this thick warp 20
A thick warp group consisting of 3 to 22 groups is shown. In addition, in this embodiment, although three are combined, one may be used. 27-
Reference numeral 29 is a thin warp yarn obtained by applying a very small amount of twist to a small number of fibers as compared with the thick warp yarns 20 to 22.
It is provided between each ~ 26. Reference numeral 30 is a thin weft yarn, which is made by twisting a small number of fibers with a very slight twist, as compared with the thick warp yarns 20 to 22, similarly to the thin warp yarn.

The thick warp yarn groups 23 to 26 are stretched horizontally so as not to bend, and the front side of the warp yarns 27 to 29 is pulled above the horizontally stretched thick warp yarn groups 23 to 26 to make a thick warp yarn group. 23-26 surface side and thin warp yarns 27-29
The lower side of the thin thread 30a from the left side to the right side of FIG.
Through, and then pulling the front side of the thin warp yarns 27 to 29 below the thick warp yarn groups 23 to 26 that are horizontally stretched,
Thin warp yarns 27-2 on the back side of the thick warp yarn groups 23-26
9 from the right side to the left side of FIG.
Pass b. By repeating this operation, the bind tape shown in the figure is woven to obtain a bind tape made of PPS fibers.

In order to further exert the shrinkage property and to increase the tensile strength, the ratio of the warp fibers is set to be larger than that of the twisted fibers and knitted so as not to bend.

The PPS fiber woven bind tape thus woven has the same mechanical strength and heat resistance deterioration property as the glass bind tape, and the outer side die 16
The ring has an outer circumference equal to the inner circumference.
The ring of the PPS fiber woven bind tape is wound around two rounds, and one part of the layer is bonded with a heat-resistant adhesive that is cured at room temperature to form a tape ring 19. The tape ring 19 configured as described above is arranged in the outer diameter side mold 16 as shown in FIG.

A glass cloth 31 is wound around the outer peripheral surface of the inner-diameter mold 17. Further, the core iron 7 is packed in the molding die 18. Then, on the upper surface of the annular element core 7,
An upper mold 3 having a release cloth 32, which is a cloth made of fluororesin fiber, and a large number of resin injection ports 33 provided on the release cloth 32.
Set 4.

Next, the process proceeds to the heat curing step by the vacuum casting method. Therefore, as described above, the molding die 18 packed with the core iron 7 is placed in the tank 35 illustrated in FIG. 7, heated to a predetermined temperature, and then the tank 35 is evacuated. Next, the liquid resin prepared by mixing in advance and prepared in the resin pot 35a is injected into the molding die 18 and further evacuated to impregnate the resin between the magnetic plate layers.

Next, the vacuum state in the tank 35 is released, and after that, when the heating device 35b gradually heats it to reach a predetermined temperature, it is heated at that temperature for a predetermined time. After the treatment for hardening the resin as described above, the unnecessary resin 36 is removed to manufacture the iron core block.

Further, when the heat shrink tape ring 19 shrinks during heating and tightens the core 7 during the above-mentioned molding process, the separation cloth 32 on the upper surface and the upper mold 34 are easily friction-free. Since it is in a slipping condition, tape ring 1
It is possible to eliminate the loss of tightening force due to 9. Further, since the upper mold 34 can be easily removed from the parting cloth 32 after the heat curing treatment, the molding mold 18
Can be easily dismantled, and finishing of the upper surface of the iron core block is unnecessary. It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the scope of the present invention.

[0033]

As described above in detail, according to the iron core block for electric equipment and the method for manufacturing the same of the present invention, firstly, the same or more than the glass bind tape is provided on the outer peripheral portion of the core having the magnetic plates radially arranged. Heat-shrinkable PPS fiber woven tape with mechanical strength was wrapped in a mold and integrated with a thermosetting resin by vacuum casting or impregnation to form an iron core block. Since the PPS fiber woven tape heat-shrinks and shrinks and hardens the resin between the magnetic plates while tightening the core, there is an effect that peeling or cracking between the magnetic plates can be prevented. Along with this, even if peeling or cracking occurs between the magnetic plates in the iron core block, the heat-shrinkable PPS fiber woven tape is firmly tightened from the outer peripheral side of the core iron to maintain the rigidity of the block-shaped iron core, It is effective in preventing noise during use and preventing the strength from decreasing.

Further, a heat-shrinkable PPS fiber woven tape having the same mechanical strength and heat deterioration resistance as the conventionally used glass bind tape is wound around the outer circumference of the core. Therefore, there is an effect that the troublesome work of alternately winding the glass bind tape and the heat-shrink tape or the multiple winding as in the conventional case becomes unnecessary. Further, since the present invention does not alternate winding with the glass bind tape, there is an effect that all the shrinking force of the heat-shrinkable PPS fiber woven tape can be used as the tightening force for the core portion.

Secondly, according to the present invention, a heat-shrinkable PPS fiber woven tape is wound around the outer periphery of a base iron core on which magnetic plates are arranged in a radial pattern, and the product is put in a mold to form the upper surface of the core and the upper metal core. Since the core block is made of thermosetting resin by vacuum casting with a release cloth interposed between the core and the shape, the heat shrinkable PPS fiber woven tape shrinks during vacuum casting heat curing. When attempting to tighten the base iron core portion by slipping, it is possible to easily slip between the upper surface of the base iron core portion and the upper die, thereby eliminating the loss of the tightening force of the tape.

Further, since the upper die can be easily removed from the release cross portion after the heat curing treatment, the forming die can be easily disassembled, and finishing of the upper surface of the iron core block is unnecessary.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of an iron core block for electric equipment of the present invention and a method of manufacturing the iron core block in a state in which a core iron is housed in a mold.

FIG. 2 is a plan view showing a state where the core iron core of the above embodiment is housed in a lower mold.

FIG. 3 is a vertical cross-sectional view showing the core block of the above embodiment taken out.

FIG. 4 is a plan view of a bind tape made of PPS fiber according to the above embodiment.

5 is a sectional view taken along the line EE in FIG.

6 is a cross-sectional view taken along the arrow line of FIG.

FIG. 7 is a schematic longitudinal cross-sectional explanatory diagram of a heating vacuum casting tank portion used for manufacturing the iron core block of the above embodiment.

FIG. 8 is a front view illustrating a conventional reactor iron core.

FIG. 9 is a plan view of a radial block iron core of the conventional example.

FIG. 10 is a plan view of a block iron core having a crack in the conventional example.

FIG. 11 is a front view of a reactor core showing another conventional example.

FIG. 12 is a vertical cross-sectional view showing a state in which an iron core block is manufactured using a conventional die.

FIG. 13 is a plan view of an iron core block manufactured by the conventional method.

[Explanation of symbols]

 1 ... Iron core block 5 ... Magnetic plate 7 ... Element core 15 ... Lower mold 16 ... Outer diameter side mold 17 ... Inner diameter side mold 18 ... Molding mold 19 ... Tape ring 31 ... Glass cloth 32 ... Releasing cloth 34 … Upper mold

Claims (2)

[Claims] 1. A molding die, in which a heat-shrinkable PPS fiber woven tape is wound around the outer periphery of a core of iron having magnetic plates radially arranged, is housed by a vacuum casting method or an impregnation method. An iron core block for electric equipment, which is characterized by being impregnated with a thermosetting resin and subjected to heat treatment to be integrated. 2. A molding die in which a heat-shrinkable PPS fiber woven tape is wound around an outer peripheral portion of a core having radial magnetic plates, and the upper surface of the core and the core An electric device characterized in that a thermosetting resin is impregnated and heat-treated by a vacuum casting method in a state where a release cloth is interposed between the molding die and an upper die to integrally manufacture the molding die. Of manufacturing iron core block.