JPH11219831A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a transformer which is high in output power, small in size, light in weight, high in reliability, and cheap by a method wherein a modified polyurethane enameled wire is wound on a low-voltage bobbin and a high- voltage bobbin respectively for the formation of a low-voltage coil and a high- voltage coil, and the low-voltage coil and high-voltage coil are impregnated or sealed up with epoxy casting resin composition. SOLUTION: A low-voltage coil 71 is composed of a plastic bobbin 2 and a modified polyurethane enameled wire 60 part-wound on it. A plastic bobbin 4 is fitted to the outside of the low-voltage coil 71, and a modified polyurethane enameled wire 60 is wound on the plastic bobbin 4 in layers interposing an insulating film between layers for the formation of a high-voltage coil 72. One or more high-voltage diodes are connected to the high-voltage coil 72, and furthermore a focus pack 6 is provided. These component members are housed in a plastic case 7, and the plastic case 7 is filled up with liquid epoxy casting resin composition 8 for insulation, and thus a fly-back transformer 73 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer, and more particularly to a casting resin for an ignition coil for an internal combustion engine, a flyback transformer for generating a high voltage applied to a cathode ray tube (CRT), or a large molded transformer. Impregnated with the composition and / or
Or related to a molded transformer.

[0002]

2. Description of the Related Art As the price of devices such as a television receiver and a CRT display monitor decreases, the demand for reducing the price of parts has become stronger. In particular, impregnation and / or
In addition, there is a more stringent demand for discounts on winding parts such as molded flyback transformers and coil devices, and competition between domestic and foreign peers has become even more severe.

[0003] Accordingly, there is an era in which the cost of production must be further reduced by reducing material costs, improving productivity and yield, promoting energy saving in the production process, and the like, including changes in constituent materials and manufacturing methods. . Further, as a method of exerting a great effect in reducing material costs, there is a method of reducing the size and weight of a flyback transformer. However, in general, if the flyback transformer is reduced in size and weight while maintaining the same output, the temperature rise becomes large, which is a problem.

[0004] As a countermeasure, there are a method of reducing the loss of the components of the flyback transformer to reduce heat generation, and a method of improving the heat resistance of the components and enabling use at a high temperature.

However, recent flyback transformers are:
There is an extremely high demand for miniaturization of devices and higher resolution and higher density of images, and the number of devices that operate at much higher frequencies than in the past is rapidly increasing. Therefore, there is a limit in compensating for the increase in the temperature rise caused by the increase in the loss caused by the high-frequency operation and the decrease in the heat radiation area due to the miniaturization only by the loss reduction of the constituent materials of the flyback transformer.

Therefore, it is possible to prevent the operating temperature from increasing due to the miniaturization and the increase in temperature due to high-frequency operation and shortening the life due to thermal degradation without increasing the material cost by combining the components. That is, how to shorten the life at a high operating temperature is a key point for reducing the manufacturing cost and reducing the size and weight.

As an example of a conventional flyback transformer used for supplying a high voltage to a cathode ray tube such as a television receiver or a display monitor using a CRT,
The flyback transformer 11 will be described with reference to FIG.
In FIG. 9, reference numeral 1 denotes a low-voltage side coil in which a polyurethane enamel wire is dividedly wound around a plastic bobbin 2, 3 denotes a high-voltage side coil in which a polyurethane enamel wire is laminated and wound around a plastic bobbin 4 via an insulating film between layers, and 5 denotes one coil. The above-mentioned high-voltage diode 6 is a focus pack made of a high-voltage resistor (however, it may include a high-voltage capacitor). These components are housed in a plastic case 7 and A liquid epoxy-based casting resin composition 8 is filled and insulated. A U-shaped core 9 is formed from both sides of the through hole 2a of the bobbin 2.
And 10 are inserted, and the end faces are joined together to form a closed magnetic circuit. A gap spacer 12 is provided between the U-shaped cores 9 and 10, and is set to a predetermined core gap.

The flyback transformer 11 is mounted on a circuit as shown in FIG. In FIG. 10, T ₁ is a horizontal drive transformer, _Tr is a horizontal output transistor, D _d is a damper diode, and C _o.
Is a resonance capacitor, C _s is a DC cut capacitor, L _d
Denotes a dummy yoke (choke coil), and 11 denotes a flyback transformer. The collector of the horizontal output transistor T _r, the primary side coil 1a of the flyback transformer 1
Is connected to one end. The other end of the primary coil 1a is fed a voltage is connected to the power supply B _1.

In the operation circuit of FIG. 10, when _Tr is switched under a predetermined condition, a positive pulse voltage of about 1200 to 1300 V _pp is generated between both terminals of the primary coil 1a. A positive pulse voltage is also induced in the side coil (secondary coil) 3. This pulse voltage is rectified by the high-voltage diode 5 (5a to 5d) for each divided coil (3a to 3d) of the secondary coil 3 and accumulated to generate a DC high voltage of about 25 to 30 kV. The required voltage is supplied from the output terminal to the anode of the cathode ray tube.

Further, another coil 1b of the low-voltage side coil 1,
Reference numerals 1c, 1d and 1e denote tertiary coils, which are coils for supplying a DC voltage or a pulse voltage to other circuits. The coil 1b is a coil for supplying a power supply voltage to a parabolic voltage generation circuit for supplying a parabolic voltage to a dynamic focus electrode of a cathode ray tube, and is 700 to 800 V (850 to 100 by pulse voltage).
A DC voltage of about 0 V _pp ) is output. The high voltage supplied to the cathode ray tube due to a trouble in a circuit or parts such as a power supply circuit or the like of the coil 1c becomes excessively high, and an abnormal voltage supplied to a protector circuit for preventing a predetermined amount or more of X-rays from being generated from the cathode ray tube. The detection coil outputs a DC voltage of about 20 to 40 V (about 25 to 50 V _{pp in} pulse voltage). The coil 1d is connected to a horizontal synchronization stabilizing circuit (AF
C to supply pulse voltage to C circuit)
A pulse voltage of about 40 V _pp is output. Coil 1
e is a coil for supplying a negative bias voltage used to increase the voltage width of the circuit operation or supplying a negative pulse voltage used to cancel a positive pulse to reduce unnecessary electric field radiation. A DC and / or pulse voltage of about -200 V (from -120 to -250 V _pp ) is output.

Next, details of the coil bobbin 2 and the low voltage side coil 1 in which a polyurethane enamel wire is dividedly wound around the coil bobbin 2 will be described with reference to FIGS. FIG.
FIG. 1A is a perspective view showing the coil bobbin 2. On the surface of the cylindrical portion 20 of the coil bobbin 2, winding grooves 21, 22, 23, 24, 25, 26,
27 and 28 are provided. At one end of the cylindrical portion 20, a plurality of terminal blocks 2b for fixing a plurality of terminals 29 for connecting each low-voltage side coil and an external circuit, and a fitting portion 2c for fitting to the case 7 are provided. It is provided. In the vicinity of the other end, a convex portion 2d to be fitted to the bobbin 4 is provided, and the end portion is formed in a cylindrical shape to be fitted to the case 7. A through hole 2 a for inserting the cores 9 and 10 is provided inside the cylindrical portion 20. FIG. 11B is a perspective view showing the low-voltage side coil 1 in which the polyurethane enamel wire 30 is dividedly wound around the coil bobbin 2 shown in FIG. 11A. The coils 1 a to 1 of the low-voltage side coil 1 are provided in the winding grooves 21 to 28 of the coil bobbin 2.
The polyurethane enamel wire 30 constituting e is divided and wound. There are various combinations for allocating the coils 1a to 1e to the winding grooves 21 to 28, but they are determined in consideration of the performance, reliability, productivity, and the like of the flyback transformer 11.

FIG. 12 shows a cross section (AA cross section) of a main part of the low voltage side coil 1 shown in FIG. 11B. In FIG. 12, a coil 1b is wound around the winding grooves 21 and 22, and the winding groove 21 starts winding from the output side (850/1000 V _pp side) and winds 1/2 to 2/3 of the whole. Turn the remaining one
２〜 to １ ／ are wound around the winding groove 22, and the end of the winding is drawn out to the terminal 29. The coil 1c has a primary side coil 1a in order to match output fluctuations of the high voltage side coil 3 and the coil 1c.
It is wound on the coil 1b of the winding groove 22 so as to be loosely coupled. Further, a coil 1e having a relatively small potential difference is wound thereon. The coil 1d is wound around the winding groove 24 because it must be tightly coupled with the primary coil 1a in order to prevent the phase deviation from the collector pulse and the waveform shape from shifting as much as possible. Then, the coil 1a is divided into winding grooves 23, 24, 26, 27, and 28 and wound on the coil 1d in order from the lowest voltage. The winding groove 25 is
Since the winding groove corresponds to the position of the gap spacer inserted into the abutting surface of the core, the coil is generally not wound in order to prevent heat generation of the coil due to leakage magnetic flux. The reason why the primary coil 1a is wound around the winding grooves 23 to 28 is that the degree of coupling with the high-voltage coil 3 is made as close as possible to reduce the internal impedance of the high-voltage power supply.
This is for improving the heat radiation of a and holding down the temperature rise of the low-voltage side coil.

FIG. 13 shows a conventional flyback transformer 1.
FIG. 3 is a cross-sectional view illustrating a winding state of a high voltage side (secondary side) coil 3 of FIG. In FIG. 13, reference numeral 4 denotes a coil bobbin, and reference numerals 3 denote coil bodies 3a to 3d in which a plurality of polyurethane enamel wires 30 and interlayer insulating films 37 are alternately wound in layers and laminated. As shown in FIG. 10, the winding end of the first layer coil 3a of the secondary coil 3 and the winding start of the second layer coil 3b are 3a.
Are connected via the high-voltage diode 5a in the direction in which the current flows in the direction from to 3b. The winding end of the second-layer coil 3b and the winding start of the third-layer coil 3c are also connected via the high-voltage diode 5b in the same manner as described above. The anode side is connected, and the cathode side is connected to the high voltage output side. In the case of the high-voltage side (secondary side) coil wound in a stacked manner as described above, the polyurethane enamel wire 30 is arranged and wound in a line in each layer as described above.
The potential difference between the polyurethane enamel wires 30 is as small as 10 to 30 V _pp without any potential difference corresponding to one turn. The potential difference between the layers is also rectified and stacked by the high voltage diode 5 in each layer, and the number of turns of each layer is generally the same, so that there is no AC potential difference and only a DC potential difference. Therefore, a thin polyurethane enamel wire 30 having a thickness of about 2 to 4 μm is used as the polyurethane enamel film 32 shown in FIG.

FIG. 14 is a diagram showing a cross section of an enamel wire (magnet wire) commonly used for a flyback transformer. An enameled wire often used for this type of flyback transformer is generally a heat-resistant grade of a polyurethane enameled wire (UEW) obtained by applying a polyurethane enamel paint that is easy to solder to a predetermined thickness and baking it. Are often used. FIG.
4 is a cross-sectional view of a polyurethane enameled wire (UEW) 30 having a polyurethane enameled film 32 baked a plurality of times by applying and baking a polyurethane enamel paint around a copper wire 31 to a predetermined film thickness.
The thickness of the coating 32 of the enamel wire 30 and the thickness of the copper wire 31 to be used are selected and used in accordance with the required withstand voltage and current capacity.

FIG. 15 shows a conventional flyback transformer 1.
It is sectional drawing which shows the other example of a structure of the 1 high voltage side (secondary side) coil. In FIG. 15A, reference numeral 38 denotes a plurality of flanges 39.
High voltage side (secondary side) coil winding part 41 in which the polyurethane enamel wire 30 is wound around the plurality of concave grooves 40 formed by the above, and a high voltage diode disposed between the high voltage side coil winding part 41 5 is a hollow plastic bobbin provided with a concave portion 42 for accommodating the plastic bobbin 2. The plastic bobbin 2 is inserted into the hollow portion 43. FIG.
(B) shows the high voltage side (secondary side) coil 3 shown in FIG.
FIG. 3 is a cross-sectional view showing a detailed winding state of FIG. As shown in FIG. 15 (b), in each of the concave grooves 40, a plurality of the polyurethane enamel wires 30 shown in FIG. These are combined to form a high-voltage side coil winding portion 41. A high voltage diode 5 is connected between the high voltage side coil winding portions 41 and 41 so as to have a polarity in which a current flows in the forward direction. The structure shown in FIG. 15 (b) is obtained by dividing the respective layers of the coil bodies 3a to 3d wound in plural layers shown in FIG.
The high voltage side coil 45 is formed by combining a plurality of 1 coils. Therefore, when the circuit is operated using the circuit shown in FIG. 10, it operates in the same manner as the case of the stacked high-voltage side coil 3 shown in FIG. However, in the case of a high-voltage side (secondary side) coil divided and wound as shown in FIG. 15, about several hundred windings are applied to each winding groove, and it is difficult to reliably form an aligned winding. Since the winding is random, in the worst case including winding collapse, an AC potential difference of several hundred volts or more is applied between the polyurethane enameled wires 30, and the thickness of the polyurethane enamel coating 32 is 15 to 2
A thick polyurethane enamel wire 30 having a film thickness of about 5 μm is used.

[0016]

Recently, as the size of television receivers and display monitors has been increased and the image quality has been improved, CRs have been developed.
Higher output of the anode electrode supplied to the T and higher frequency of horizontal deflection are rapidly progressing, and the heat generation temperature of the flyback transformer is higher than before. In addition, with the spread of information networks and digital broadcasting, the chances of continuously using display monitors and television receivers for a long time have increased, and the rate of continuous operation of the flyback transformer at high temperatures for a long time has increased rapidly.

[0017] Therefore, insulation failure which is considered to be caused by insulation deterioration of the polyurethane enamel wire constituting the flyback transformer impregnated or molded with the epoxy-based casting resin composition 8 such as the flyback transformer 11 shown in FIG. The number of market failures has been increasing recently and is becoming a state that cannot be ignored.

Similar failures in the market due to poor insulation have also occurred in ignition coils for internal combustion engines impregnated or molded with epoxy-based casting resin compositions.

Moreover, this tendency occurs only in flyback transformers and ignition coils impregnated or molded with the epoxy-based casting resin composition, and other casting resin compositions such as silicone In a flyback transformer or an ignition coil impregnated or molded with a system casting resin composition, there has been no such failure from the past to the present.

The polyurethane enamel coating 32 constituting the insulating coating of the conventional polyurethane enameled wire (UEW) 30 is eroded by an epoxy compound, or its insulation properties are largely degraded by hydrolysis. In applications where the electric power is applied, the service life is short, and in order to cover this, the enamel film is made thicker than the enamel film thickness of 0 or more specified in JIS C3202.
For this reason, the production cost of the polyurethane enameled wire (UEW) has been extremely high and expensive. In addition, in the high-voltage coil 45 as shown in FIG.
Since conductors with a diameter of about 0.04 to φ0.05 mm are often used, and when the diameter of the conductor is reduced, it is limited to an average coating thickness of about 20 μm due to problems in production yield of the enameled wire and coating quality. In order to prevent short-circuit failure due to insulation deterioration of the enamel coating, it is necessary to reduce the width of the winding groove 40 of the bobbin 38 or to reduce the number of windings per groove. There was a limit to the conversion. Also, due to its structure, it is difficult to eliminate a portion having a large line potential difference even if the above-mentioned considerations are taken, and it is very difficult to eliminate short circuit failure between lines.
The production cost is also very high.

[0021] Furthermore, if an attempt is made to reduce the size and weight in order to cover the high production cost, the operating temperature of the equipment will increase, the life will be further shortened, polyurethane enameled wire cannot be used, and the solder peeling of the enamel film will be compared. There has been such a problem that the workability of the polyurethane enameled wire, which is possible at a very low temperature, cannot be sufficiently exhibited.

Therefore, the workability is good by the combination of inexpensive members, and even if it is operated continuously for a long time in a high temperature state, there are few failures, the reliability is high, and a small, lightweight and inexpensive flyback transformer or ignition coil is used. It has been extremely difficult to realize a transformer impregnated and / or molded with a casting resin composition (hereinafter simply referred to as a “resin mold type transformer”) by the conventional technique.

The present invention has been made in view of the above circumstances, and has as its object to solve the above-mentioned disadvantages of the prior art, and to provide a high-temperature composition which does not easily change its composition with moisture in a high-temperature sealed state. An object of the present invention is to provide a resin-molded transformer suitable for reducing output, size, and weight.

It is another object of the present invention to provide a highly reliable and inexpensive resin mold type transformer.

Still another object of the present invention is to provide a resin mold type transformer which can remarkably improve the wet heat resistance, solvent resistance, and high temperature solder bath immersion peeling properties required during production and operation in a market. To provide.

Still another object of the present invention is to provide a resin-molded transformer with an environmentally friendly manufacturing method and configuration.

Still another object of the present invention is to provide a silicone-based casting resin composition having an expensive heat-resistant property when impregnated and molded with an epoxy-based casting resin composition even if the enamel film is thin. It is an object of the present invention to provide a resin-molded transformer capable of obtaining the same life characteristics as those obtained by impregnation and molding and reducing the unit cost of the product.

Still another object of the present invention is to provide a resin molded transformer suitable for high frequency applications.

It is still another object of the present invention to provide a resin-molded transformer that satisfies both the customer's life guarantee requirement and price reduction requirement.

[0030]

In order to achieve the above object, the present inventors have developed a temperature class B (130 ° C.) having a heat-resistant life of IEC-172, which is widely used in this type of resin-molded transformer. Polyurethane enamel paint is repeatedly applied and baked a plurality of times to obtain a polyurethane enamel wire (φ0.26 VOUEWB used by our company) with an enamel film thickness of 0 or more as specified in JIS C3202 and an average film thickness of 40 μm. Using a plastic bobbin 2 so that a heat resistance test can be performed in a state close to the configuration of the flyback transformer 11, a coil 53 for heat resistance test as shown in FIG. The differences were considered.

FIG. 16A shows a plastic bobbin 2.
FIG. 4 is a perspective view of a test coil bobbin 51 provided with a polyurethane enamel wire serving as a negative electrode. As shown in FIG. 16A, the coil bobbin 51 has a polyurethane enamel wire (φ0.26 V0UEWB) 30 serving as a negative electrode 50 connected to the terminal 29a of the plastic bobbin 2.
Of the winding groove 2 so as to cross the winding grooves 21 to 27.
8 along the surface of the bobbin, and hooked on the flange 20b at the boundary between the winding groove 28 and the winding groove 27 to be folded back.
The terminal is pulled down along the surface of the bobbin so as to cross another portion of Nos. 1 to 27, and the terminal is wrapped around the terminal 29b to form the negative electrode 50.

FIG. 16B shows a test coil bobbin 51.
And a polyurethane enameled wire (φ
FIG. 2 is a perspective view of a heat-resistant life test coil 53 in which 0.26 V0UEWB) 30 is continuously wound around each groove. As shown in FIG. 16 (b), the coil 53 for heat resistance life test is formed by winding one end of the polyurethane enamel wire 30 serving as the positive electrode 52 to the terminal 29d, and continuously winding the winding grooves 21 to 24 and 26 to 28. Wire and the end of the winding along the coil.
The positive electrode 52 is formed by being connected to the pull-down terminal 29c up to c.

A plastic bobbin 4 is inserted into the heat-resistant life test coil 53 and is housed in a plastic case 7 (not shown). Liquid epoxy resin composition for casting (KE-5207 used by our company) and liquid silicone resin composition for casting (KE-121 manufactured by Shin-Etsu Chemical Co., Ltd.)
2) was injected, filled, impregnated and molded to perform insulation treatment, and heat-resistant life test samples each having a configuration similar to the flyback transformer 11 shown in FIG. 9 were prepared.

These samples were attached to a polyurethane enamel wire heat resistance life test circuit shown in FIG. 17 and tested under predetermined conditions. In FIG. 17, T ₁ is a horizontal drive transformer,
_Tr is a horizontal output transistor, D _d is a damper diode, _Co is a resonance capacitor, L is a choke coil, 53
/ 56 life of heat resistance test coil, B ₁ is a driving power source. As shown in FIG. 17, the terminal 29a is grounded,
To 9c, a television pulse voltage having a frequency of 82.0 kHz, a retrace time of 2.5 μS, and a pulse peak value of 1500 V _pp was applied.
Continuous power application was performed in an atmosphere at an ambient temperature of 130 ° C., 140 ° C., and 150 ° C. until breakdown.

FIG. 18 shows the result. In FIG. 18, the estimated life curve D is for a coil that has been insulated with an epoxy-based casting resin composition, and the estimated life curve C is for a coil that has been insulated with a silicone-based casting resin composition. Things. From these results, it was found out that the life of the coil insulated with the epoxy-based casting resin composition was short and the epoxy-based casting resin composition was the cause of the coil short-circuit, similarly to the market failure.

The epoxy-based resin composition for casting is generally
Mixture of bisphenol A diglycidyl ether (main agent) and epoxy compound (diluent such as diethylene glycol diglycidyl ether and dibromophenol monoglycidyl ether), inorganic filler (antimony compound powder,
Halogen-based flame retardant powder, red phosphorus powder, hydrated alumina powder, silica powder, etc.), methyltetrahydrophthalic anhydride (acid anhydride curing agent), and a curing accelerator.

For each of these epoxy-based resin compositions for casting, a polyurethane enameled wire having a polyurethane enamel coating (φ0.26 VOUEW used by our company) was used.
B) was immersed, and the degree of deterioration of the film due to pencil hardness (4H) was examined. The results shown in Table 1 were obtained.

[0038]

[Table 1] From this result, the polyurethane enamel film is violently attacked by diethylene glycol diglycidyl ether as a diluent, and slightly affected by methyltetrahydrophthalic anhydride as a curing agent and pure water. Then, it was found that it was hardly attacked by bisphenol A diglycidyl ether as the main resin of epoxy resin, dibromophenol monoglycidyl ether as the diluent, flame retardant and silicone oil.

The present invention is based on the above findings, and comprises a low-voltage side coil wound on a low-pressure bobbin using a modified polyurethane enameled wire, and a coil wound on the low-pressure bobbin using the modified polyurethane enameled wire. And at least one of a low-pressure side coil and a high-pressure side coil impregnated with an epoxy-based resin composition for casting and / or molded. Here, "modified polyurethane enameled wire" refers to a polyesterimide resin obtained by reacting an imide acid formed by reacting an excess of tricarboxylic acid and a diamine with a polyhydric alcohol on a conductor such as a copper wire. , A polyurethane enameled wire obtained by baking a modified polyurethane enamel film containing a stabilized isocyanate.
The transformer to which the present invention is applied is a transformer which has been impregnated and / or molded with an epoxy-based resin composition for casting, and which has a high voltage applied to an ignition coil and a cathode ray tube (CRT) for an internal combustion engine. Or a large mold transformer in the field of heavy electrical equipment.

In general, polymers having similar solubility parameters (hereinafter referred to as “SP value”) have good adhesion and compatibility, and the SP value of each polymer tested is examined. The relationship is as shown in Table 2, where the diluent diethylene glycol diglycidyl ether and the SP value of the polyurethane enamel paint are the closest, and then the curing agent methyltetrahydrophthalic anhydride shows a similar value. I have.

[0041]

[Table 2] Therefore, the SP value is the closest to that of the polyurethane enamel paint.
To 50 parts by weight of diethylene glycol diglycidyl ether (Epiol E-1 manufactured by NOF Corporation)
00) in a 90 ° C. solution, a polyurethane enamel wire having an average thickness of a polyurethane enamel film of 40 μm (used by our company)
0.26 VOUEWB) was immersed in a twisted pair (two twisted) sample prepared according to JIS C3202 for a predetermined time, and then the AC withstand voltage breakdown level was examined. The results are shown in FIG. This result shows that the immersion time is only 10
This indicates that the breakdown voltage is reduced to about half in 30 minutes and about 1/4 in 30 minutes.

From these experimental results, of the epoxy resin composition for casting, the SP value is similar to that of the polyurethane enamel film, and the polyurethane enamel film is attacked by the influence of the low molecular weight solution component, and the insulation properties are degraded. However, it is considered that the difference between the estimated life curves C and D shown in FIG. 18 has occurred.

Accordingly, SP of the modified polyurethane enamel film used for the modified polyurethane enamel wire of the present invention
The value is preferably different from that of the epoxy-based casting resin composition. By the way, in order to prevent environmental pollution, it is better not to use a flame retardant such as a halogen flame retardant or an antimony compound in the plastic member or the epoxy resin composition for casting. Therefore, the epoxy-based casting resin composition of the present invention preferably contains a metal hydrate such as hydrated alumina powder as a main component of the flame retardant. The epoxy resin composition for casting of the present invention preferably contains diethylene glycol diglycidyl ether as a main component of the diluent. S of diethylene glycol diglycidyl ether
Considering that the P value is 9.81, the SP value of the modified polyurethane enamel film used for the modified polyurethane enameled wire of the present invention is preferably approximately 10.5 to 10.85. The SP value is preferably larger than the SP value of the epoxy-based resin composition for casting. However, in consideration of the case where the epoxy resin is also used for the epoxy-based resin composition for bromide-based casting, a diluent (dibromophenol monoglycidyl ether) is used. ) SP value 1
This is because it is better to be smaller than 0.9. Specifically, S
In order to increase the P value, the imide group, the aromatic ring, and the degree of branching (the state of the three-dimensional structure and the crosslink density) in the epoxy resin composition for casting may be increased.

In the immersion experiment shown in FIG. 19, the temperature of the solution in which the polyurethane enameled wire (UEW) was immersed was 9
The test was conducted at 0 ° C. when the epoxy-based resin composition for casting was cured during flyback transformer production.
At a temperature of 90 ° C., it is still in a state before gelation, and 90 to 1
This is because it is considered that the test is immersed in the temperature of about 00 ° C. for several tens of minutes, and it is considered appropriate to conduct the test at a temperature of about 90 ° C.

The polyurethane constituting the polyurethane enamel film is based on a urethane bond of ＮＨNHＮＨCO ・ O ・.

When moisture reacts with this bond,

ＮＨNHＮＨCO〜O + H ₂ O → NH ₂ + CO ₂ + HO〜 (1) Hydrolysis is caused, urethane bonds are broken, and electrical insulation characteristics cannot be maintained. The non-blome or brome-based flame-retardant epoxy resin composition for casting is filled with a large amount of hydrated alumina powder as a flame-retardant main agent or a flame-retardant auxiliary.

For example, in an epoxy casting resin composition filled with a brome-based flame retardant powder, the content of the hydrated alumina powder is 40 to 100 parts by weight of the epoxy mixture.
It is contained in an amount of about 100 parts by weight, and in the non-bloom type epoxy resin composition for casting, a hydrated alumina powder is used as a flame retardant main agent. About 10 parts by weight. This hydrated alumina powder has a higher moisture content than silica powder or the like, and also causes poor moisture resistance of the epoxy-based casting resin composition.

Further, the hydrated alumina powder has the chemical formula Al
(OH) ₃ or Al ₂ (OH) ₃ .

## EQU2 ## Al (OH) ₃ → AlO.OH + H ₂ O (2)

## EQU3 ## A dehydration reaction as shown by Al ₂ (OH) ₃ → Al ₂ O ₃ + 3H ₂ O (3) occurs to separate water of crystallization. This decomposition and dehydration reaction is said to take place at about 240 ° C. However, the hydrated alumina powder actually used contains various purity, and the adsorbed water and water of crystallization are separated from about 100 ° C. It is believed that some may occur.
Therefore, it is considered that a blown or non-bloomed epoxy resin composition containing a large amount of alumina powder contains a considerable amount of water at high temperatures in combination with the above-mentioned poor moisture resistance.

Incidentally, as a result of the heat resistance life test of the enameled wire of the present inventors, based on general criteria for product design and a certain safety factor, etc., the high voltage side coil of the present invention can be determined. The voltage between adjacent modified polyurethane enameled wires in the inside or the voltage between adjacent modified polyurethane enameled wires in the low voltage side coil should be 20 V _pp or more per 1 μm of the thickness of the modified polyurethane enamel film. Is preferred.

[0050]

Embodiments of the present invention will be described below with reference to the drawings. The parts that can be described with the figures and symbols described in the conventional example are omitted from the description using the same figures and symbols.

(First Embodiment) FIG. 1A shows a schematic structure of a flyback transformer 73 according to a first embodiment of the present invention. FIG. 1B is a cross-sectional view of the modified polyurethane enameled wire 60 used for the low voltage side coil 71 and the high voltage side coil 72 of the flyback transformer 73 shown in FIG.

As shown in FIG. 1A, a flyback transformer 73 according to the first embodiment of the present invention has a low voltage side coil 71 and a high voltage side coil 72. The low voltage side coil 71 is configured by winding a modified polyurethane enamel wire 60 around a plastic bobbin 2 in a divided manner. The plastic bobbin 4 is fitted on the outside of the low voltage side coil 71, and the high voltage side coil 72 is configured by laminating and winding a modified polyurethane enamel wire on the plastic bobbin 4 with an insulating film interposed between layers. High voltage side coil 7
2 is connected to one or more high-voltage diodes 5. Further, as shown in FIG. 1A, a focus pack (which may include a high-voltage capacitor) 6 composed of a high-voltage resistor is provided. In the flyback transformer 73 according to the first embodiment of the present invention, these components are housed in a plastic case 7, and the case 7 is filled with a liquid epoxy-based casting resin composition 8. Insulated. Then, U-shaped cores 9 and 10 are inserted from both sides of the through hole 2a of the bobbin 2, and both ends are joined to form a closed magnetic path. U-shaped core 9
A gap spacer 12 is provided between and
It is set to a predetermined core gap.

The modified polyurethane enameled wire 60 used for the low voltage side coil 71 and the high voltage side coil 72 is shown in FIG.
As shown in (b), around the conductor 62, a polyesterimide resin obtained by reacting an imidic acid obtained by reacting excess tricarboxylic acid and diamine with a polyhydric alcohol,
The modified polyurethane enamel film 61 is obtained by repeating the operation of applying and baking a modified polyurethane enamel paint containing a stabilized isocyanate a plurality of times until a predetermined film thickness is obtained.

The aromatic tricarboxylic acid used in the modified polyurethane enameled wire 60 includes trimellitic acid, trimellitic anhydride and the like. Also, as the diamine,
4,4'-diaminodiphenylmethane, 4,4'-methylenedianiline, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone,
3,3'-diaminodiphenyl sulfone, paraphenylenediamine, metaphenylenediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, metaxylenediamine, 4,4'-dimethylheptamethylenediamine, diaminodiphenylketone These are used alone or in combination of two or more.

As the alcohol component, a polyhydric alcohol is used. For example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, glycerin, triglycol Examples include methylolethane, trimethylolpropane, hexanetriol pentaeristol, and trishydroxyethyl isocyanurate.

When reacting an aromatic tricarboxylic acid with a diamine, the molar ratio is desirably 2: 1. The obtained imidic acid is reacted with an excess of the alcohol component, but there is no particular restriction on the numerical value.

As for the stabilized isocyanate, the stabilized aromatic polyvalent isocyanate Millionate MS-50,
Coronate 2503 (trade name of Nippon Polyurethane Industry)
A, a stable and stable aliphatic polyisocyanate
P Stable (Bayer company name) or the like is used.

These resin compositions are dissolved in an organic solvent such as phenol, cresol, xylenol, or xylene, or a combination of a plurality of them.
It is also possible to add a powder such as tin or lead, or a metal salt, a dye, a leveling agent or a lubricant, or another resin.

The modified polyurethane enamel wire 60 obtained by applying the modified polyurethane enamel paint obtained as described above on a conductor 62 and baking it is excellent in heat resistance, and has a higher cross-link density of the insulating film than conventional polyurethane enamel wire, polyesterimide enamel wire and the like. And the moisture and heat resistance and solvent resistance are greatly improved. Also, compared to the conventional soldered polyester imide enameled wire, the soldering temperature is 40 to 100 ° C.
It has such features that it can be lowered.

Specifically, the modified polyurethane enamel wire 60 according to the first embodiment of the present invention is obtained by coating a modified polyurethane enamel paint on a copper wire having a conductor diameter of 0.26 mm.
Using an electric furnace, (1) JIS C coated and baked 11 times
Modified polyurethane enameled wire with a finish of 0 or more types of enameled wire as specified in 3202 Special 0CPW-H (trade name of Hanashima Electric Cable Co.), (2) JIS C coated and baked 5 times
Modified polyurethane enameled wire 1CPW-H (trade name of Hanashima Electric Wire Co., Ltd.) having a finished enameled wire film thickness specified in 3202, (3) JIS C3202 coated and baked four times
Modified polyurethane enameled wire 2CPW-H (trade name of Hanashima Electric Wire Co., Ltd.)
It is.

As shown in FIG. 2A, the low voltage side coil 7
Reference numeral 1 denotes a plastic bobbin 2 and a polyurethane bobbin wire wound around a plastic bobbin. A winding groove partitioned by a plurality of flanges is provided on the surface of the tubular portion of the coil bobbin 2. At one end of the cylindrical portion, a plurality of terminal blocks for fixing a plurality of terminals for connecting each low-voltage side coil to an external circuit and a case 7 shown in FIG. Are provided. In the vicinity of the other end, there is provided a convex portion for fitting with the plastic bobbin 4 on the high pressure side, and the end portion is formed in a cylindrical shape for fitting with the case 7. A through hole 2a for inserting the cores 9 and 10 is provided inside the cylindrical portion. Plastic bobbin 2
The modified polyurethane enameled wire 60 constituting each coil of the low-voltage side coil 71 is divided and wound in the winding groove. There are various combinations for allocating each coil to the winding groove.
It is determined in consideration of reliability, productivity, etc. The cross section of the main part of the low voltage side coil 71 is the same as that of FIG. 12 described in the related art.

FIG. 2B is a sectional view showing a winding state of the high voltage side (secondary side) coil 72 of the flyback transformer 73 according to the first embodiment of the present invention. As shown in FIG. 2B, the high-voltage side (secondary side) coil 72 according to the first embodiment of the present invention has a modified polyurethane enameled wire 60 and an interlayer insulating film 37 alternately formed on a plastic coil bobbin 4. Body 3 wound in layers and laminated in multiple layers
a to 3d. As shown in the circuit diagram of FIG. 10, at the end of the winding of the first-layer coil 3a and at the beginning of the winding of the second-layer coil 3b of the secondary-side coil 72, the high-voltage diode 5a is turned in the direction in which current flows from 3a to 3b. Connected through. The winding end of the second-layer coil 3b and the winding start of the third-layer coil 3c are also connected via the high-voltage diode 5b in the same manner as described above. The anode side is connected, and the cathode side is connected to the high voltage output side. In the case of the high-voltage side (secondary side) coil 72 thus laminated and wound, the modified polyurethane enameled wire 60 is wound in a line in each layer, and the potential difference between the modified polyurethane enameled wires 60 is the potential difference of one turn. Only
Very small, about 10 to 30 V _pp . The potential difference between the layers is also rectified and stacked by the high voltage diode 5 in each layer, and the number of turns of each layer is generally the same, so that there is no AC potential difference and only a DC potential difference. ing.

FIG. 3 is a sectional view showing another example of the structure of the high voltage side (secondary side) coil of the flyback transformer according to the first embodiment of the present invention. The high pressure side (secondary side) coil shown in FIG. 3 is a hollow plastic bobbin 38 having a plurality of concave grooves 40 formed by a plurality of flanges 39.
, A modified polyurethane enameled wire 60 is wound thereon. The plastic bobbin 38 includes a high voltage side (secondary side) coil winding portion 41 and a high voltage side coil winding portion 41.
Recess 42 for accommodating high voltage diode 5 disposed between
And Hollow part 4 of plastic bobbin 38
The plastic bobbin 2 on the low pressure side is inserted into 3. FIG. 3B is a cross-sectional view showing in detail a winding state of the high voltage side (secondary side) coil 74 shown in FIG. FIG.
As shown in (b), in each of the grooves 40, a plurality of windings of the modified polyurethane enamel wire 60 shown in FIG. Has formed. A high voltage diode 5 is connected between the high voltage side coil winding portions 41 and 41 so as to have a polarity in which a current flows in the forward direction. The structure shown in FIG. 3B is a multi-layer wound coil body 3a shown in FIG.
~ 3d is divided into multiple parts and wound separately.
The high-voltage side coil 74 is formed by combining a plurality of the divided coil winding portions 41. Therefore, when the circuit is operated using the circuit shown in FIG. 10, it operates in the same manner as the case of the stacked high-voltage side coil 72 shown in FIG. 2B.
However, as shown in FIG. 3, in the case of the high-voltage side (secondary side) coil which is divided and wound, about several hundred windings are applied to each winding groove, and the winding method can be surely aligned. Since the winding is difficult and random, in the worst case including the collapse, an AC potential difference of several hundred volts or more is applied between the modified polyurethane enameled wires 60.

The flyback transformer 73 according to the first embodiment of the present invention basically has a function as a resin mold type transformer similar to the conventional flyback transformer 11. Therefore, if the flyback transformer 73 according to the first embodiment of the present invention is mounted and operated on the circuit shown in FIG. 10, it operates almost in the same manner as the conventional flyback transformer 11, so that the detailed operation will be described. Omit.

In the flyback transformer 73 according to the first embodiment of the present invention, a halogen-based flame retardant, an antimony compound, or the like is added to a plastic member or an epoxy-based casting resin composition in order to prevent environmental pollution. Decided not to use flame retardants.

As the plastic member, a polyphenylene oxide resin, a modified polyphenylene oxide resin, or the like is used. As the casting resin composition, a non-bloom epoxy-based casting resin composition, for example, Hitachi Chemical Co., Ltd. KE-5303 or the like.

The non-bloom epoxy resin composition for casting is generally a mixture of bisphenol A diglycidyl ether (base) and a diluent of an epoxy compound (such as diethylene glycol diglycidyl ether), a metal hydrate (hydration). Alumina powder: a flame retardant accelerator, an acid anhydride curing agent (such as methyltetrahydrophthalic anhydride), and a curing accelerator.

The modified polyurethane enameled wire (φ0.26 special 0CPW-H manufactured by Hanashima Electric Cable Co., Ltd.) used in the flyback transformer of the present invention was added to each of these non-bloom epoxy resin compositions for casting. When the film was immersed and examined for the degree of deterioration of the film due to pencil hardness (4H), the results shown in Table 3 were obtained, and it was confirmed that the film was not damaged as in the conventional example shown in Table 1.

This is because the composition of the modified polyurethane enamel paint used in the present invention is changed to solve the drawbacks of the conventional polyurethane enamel paint, and the heat resistance, solvent resistance, hydrolysis resistance and SP value are changed. It is because it has improved.

Specifically, high heat resistance, high solvent resistance, S
To increase the P value, the imide group, the aromatic ring and the degree of branching (the state of the three-dimensional structure and the crosslink density) may be increased, and to achieve high hydrolysis resistance, the aromatic ring and the degree of branching may be increased. And the ester bond with the secondary OH group may be reduced.

[0071]

[Table 3] Table 4 shows the difference in composition between the modified polyurethane enamel paint used in the present invention, the conventional general-purpose polyurethane enamel paint and the heat-resistant polyurethane paint for flyback transformer (imide-modified polyurethane enamel paint).
In each case, the values in Table 4 are expressed as ratios when each group of the general-purpose polyurethane enamel paint is set to 1. However,
The imide group is represented by a ratio when the value of the imide-modified polyurethane enamel paint is set to 1.

[0072]

[Table 4] Although the quantitative relationship between the number of the reactive groups and the change in the SP value cannot be clearly described from the correlation with other groups, the influence of the imide group, the aromatic ring and the It increases with an increase in the degree of branching (the state of the three-dimensional structure and the crosslink density). From these, the increase in SP value is due to
Heat resistance and solvent resistance are also improved.

The modified polyurethane enamel paint used in the present invention has the composition shown in Table 4, and its SP value is 1
0.75 and 10.0 of conventional polyurethane enamel paint
The SP value of a low-molecular solution (diethylene glycol diglycidyl ether) of a non-bloom epoxy-based casting resin composition in which the conventional polyurethane enamel film is significantly attacked is 9.81 ( (See Table 2), and the composition is such that the solvent resistance and the hydrolysis resistance are also greatly improved. Therefore, as shown in Table 3, the enamel film is hardly attacked.

As described above, although the composition is excellent in solvent resistance and hydrolysis resistance, the SP value of the non-bloom epoxy resin composition and the SP value of the modified polyurethane enamel paint are the same. The SP value of the modified polyurethane enamel paint should be 10.3 for the acid anhydride curing agent (methyltetrahydrophthalic anhydride) and bisphenol A as the main component.
10.4 between SP values of 11.0 for diglycidyl ether
Although it is preferable to set it to about 10.9, more preferably, the SP value of the diluent (dibromophenol monoglycidyl ether) is set to 10 in consideration of the case where it is also used for a brome epoxy resin composition. .9 and more preferably the SP value is large.
It is good to choose about 0.85.

In order to confirm these results in more detail, a conventional polyurethane enameled wire (φ0.26 V
0UEWB) in a 90 ° C. solution of diethylene glycol diglycidyl ether (Epiol E-100, manufactured by NOF CORPORATION), a violently attacked enamel film, of the modified polyurethane enameled wire used in the present invention. 40 μm, 15 μm, 10 μm (φ0.26 special 0CPW-H, 1CPW-H, manufactured by Hanashima Electric Cable Co., Ltd.)
2CPW-H) and a conventional heat-resistant polyurethane enameled wire for flyback transformer (imide-modified polyurethane enameled wire) having an average enamel coating thickness of 40 μm and 15 μm (φ0.26 special 0UEW-FT manufactured by Hanashima Electric Cable Co., Ltd.
1UEW-FT) and a twisted pair (two twisted) sample prepared according to JIS C3202 are immersed for a predetermined time,
Thereafter, the AC withstand voltage breakdown level was examined, and the results are shown in FIG. The result is a heat resistant polyurethane enameled wire for a conventional flyback transformer (φ0.26, specially 0UEW).
-FT, 1UEW-FT), the withstand voltage breakdown value is reduced to less than half when the immersion time is only 10 minutes, whereas the modified polyurethane enameled wire (φ0.26, special 0, 1, 2CPW-H) used in the present invention is used. ) Has a very small reduction rate of the withstand voltage breakdown value, and the average enamel film thickness is 10 μm (φ0.
26 2CPW-H), when the immersion time is 30 minutes, a very large improvement effect that the withstand voltage value is superior to that of the conventional example having an average enamel film thickness of 40 μm (φ0.26, especially 0UEW-FT) is shown. ing.

In the non-bloom type epoxy resin composition for casting, a large amount of a flame-retardant main agent is used in order to ensure flame retardancy without using a flame retardant such as an antimony compound as in the prior art. Hydrated alumina is used. others,
During high-temperature operation, surface adsorbed water or water of crystallization may be partially released, and it is more susceptible to moisture than conventional brome-based flame-retardant epoxy-based casting resin compositions. The insulation breakdown level in a wet state was also confirmed.
Table 5 shows the results. As a result, the modified polyurethane enameled wire (CPW-H) used in the flyback transformer according to the first embodiment of the present invention is a polyurethane-based solderable enameled wire but is second only to a polyamideimide enameled wire. It has been found that it has excellent moisture and heat resistance.

As a comparative example, a conventional heat-resistant polyurethane enameled wire for a flyback transformer (φ0.26
1UEW-FT ... F type), polyester enamel wire (φ0.26 1PEW ... F type), solderable polyester imide enamel wire (φ.26 1EIW)
... H class), polyamide-imide enameled wire (φ0.2
6 AIW... N types).

[0078]

[Table 5] From the various test results described above, the modified polyurethane enameled wire (CPW-H) used for the flyback transformer according to the first embodiment of the present invention is obtained by using a non-bloom epoxy resin composition for casting. The flyback transformer was manufactured using this method, and it was confirmed that it had excellent resistance to various factors that would damage the enamel wire when operated in the market.

That is, the modified polyurethane enamel paint was wound using the modified polyurethane enamel wire 60 applied and baked on the conductor 62, and impregnated and / or molded with a non-bloom epoxy-based casting resin composition. The flyback transformer according to the first embodiment of the present invention has no failure due to insulation failure which is considered to be insulation deterioration of the winding, unlike the conventional flyback transformer even when used continuously at a high temperature for a long time. Have sufficient characteristic values.

Further, in order to confirm this fact, a plastic bobbin 2 was used by using the above-described constituent materials so that a heat resistance life test could be performed in a state close to the structure of the flyback transformer 73 of the present invention, as shown in FIG. Such a coil 66 for heat resistance life test was prepared and tested.

FIG. 5A is a perspective view of a test coil bobbin 63 having a plastic bobbin 2 provided with a modified polyurethane enamel wire serving as a negative electrode. As shown in FIG. 5 (a), this coil bobbin 63 has a modified polyurethane enameled wire (φ0.26 2CPW-H) serving as a negative electrode 64 on the terminal 29a of the plastic bobbin 2.
60, and pulls up along the surface of the bobbin to the winding groove 28 so as to cross the winding grooves 21 to 27.
And hooked on the flange 20b at the boundary of the winding groove 27 and folded back, lowered along the surface of the bobbin so as to traverse another part of the winding grooves 21 to 27, wrapped the terminal to the terminal 29b, and pulled the negative electrode 64 Make up.

FIG. 5B shows a modified polyurethane enameled wire (φ
0.26 2CPW-H) 60 is a perspective view of a heat-resistant life test coil 66 in which 60 is wound continuously in each groove. As shown in FIG. 5B, the coil for heat-resistant life test 66
At 9d, one end of the modified polyurethane enameled wire 60 serving as the positive electrode 65 is wound, continuously wound around the winding grooves 21 to 24, 26 to 28, and the winding end is arranged along the coil to make the terminal 2
Pull it down to 9c and connect it to the terminal 29c.
Is composed.

A plastic bobbin 4 is inserted into the heat-resistance life test coil 66 and housed in a plastic case 7 (not shown), and a non-bloomed liquid epoxy resin composition for casting is placed in the case. (Hitachi Chemical Industry Co., Ltd.)
KE-5303) was injected, filled, impregnated and molded to perform insulation treatment, and two types of samples for a heat life test having a configuration similar to the flyback transformer 73 were prepared.

These samples were mounted on the enameled wire heat-resistant life test circuit shown in FIG. 17 and tested under predetermined conditions. FIG.
As shown in FIG. 7, the terminal 29a is grounded, a television pulse voltage having a frequency of 82.0 kHz, a retrace time of 2.5 μS, and a pulse peak value of 1500 V _pp is applied to the terminal 29c, and an ambient temperature of 1 V is applied.
Continuous power application was performed in an atmosphere of 30 ° C., 140 ° C., and 150 ° C. until breakdown. FIG. 6 shows the result.

The life curve B indicates that the average enamel film thickness of the modified polyurethane enameled wire 60 was 10 μm
The estimated life characteristics are shown in the case of using (φ0.26 2CPW-H) and using, as the negative electrode 64, a solder plated wire obtained by peeling the enamel coating of a φ0.26 enamel wire by soldering. In this enamel wire heat life test,
One of the wires (the wire on the minus electrode 64 side) is a bare wire obtained by peeling off the enamel coating by soldering.
m. The life curve A shows that the average enamel film thickness of the modified polyurethane enameled wire 60 is 10 μm (φ0.26 2CPW-H) on the negative electrode 64 and the positive electrode 65.
The following shows the estimated life characteristics in the case of using the above. Life curve A
In the heat resistance life test for enameled wire shown in (1), the enamel coating is present on both the wire on the minus electrode 64 side and the wire on the plus electrode 65 side, so that the film thickness between the wires is 20 μm. FIG.
(Lifetime curves C and D) are plotted in a superimposed manner. Compared with the results of the conventional example, the estimated life characteristics (lifetime curve C) obtained by performing the insulation treatment with the silicone-based casting resin composition of the conventional example, and the insulation treatment with the non-bloomed epoxy-based casting resin composition were performed. And the estimated life characteristic (life curve A) of the flyback transformer according to the first embodiment of the present invention shows almost the same life curve. As described above, the life curve C of the conventional example is an estimated life characteristic in which there is no short-circuit failure due to insulation deterioration of the enameled wire in the market.

This means that the thickness of the enamel film is 40 μm in the case of the conventional example using an expensive silicone-based casting resin composition (interline film thickness 80 μm ... 18.75 V _pp per 1 μm film thickness). Is required, whereas the first of the present invention
In the case of the flyback transformer according to the embodiment of the present invention, it is possible to use an inexpensive non-bloom epoxy resin composition for casting based on 10 μm (line-to-line film thickness 20 μm...
At 75.00 Vp _{- p} ). In addition, in the case of the flyback transformer according to the first embodiment of the present invention, the enamel film thickness between lines is 10
Estimated life characteristics of 1 μm (15000 V _pp per 1 μm of film thickness) (see life curve B in FIG. 6) and the conventional enamel film thickness of 40 μm (interline film thickness of 80 μm... 1 μm film thickness)
Estimated life characteristics (see life curve D in FIG. 18) when insulation treatment is performed with an epoxy-based resin composition for casting using a polyurethane enameled wire of 18.75 Vp- _p per m (see FIG. 18). It shows the life characteristics.

The results were as shown in FIG. 4, Tables 3 and 5, and the modified polyurethane enameled wire (CPW-H)
Is enameled by a conventional heat-resistant polyurethane enameled wire for a flyback transformer (VOUEWB or UEW-F).
T), the heat resistance and the cross-linking density are higher, so that the moisture and heat resistance and the solvent resistance are remarkably excellent and the productivity is high.
The combination of a two-layer modified denatured polyurethane enameled wire (2CPW-H) specified in IS C3202 and an inexpensive epoxy resin composition for casting makes it possible to obtain a highly reliable flyback transformer with good heat resistance. Is shown.

Accordingly, in the case where the line voltage of the coil must be increased due to its structure, as in the case of the divided high-voltage side coil 74 as shown in FIG. 3, its ability is further exerted. For example, when the worst case of the line voltage is about several hundred volts as in the conventional example, a modified polyurethane enameled wire (CPW-H) having an enamel coating thickness of 3 to 4 μm may be used. If a modified polyurethane enamel wire (2CPW-H) having an enamel film thickness of about 10 μm is used, the number of turns per groove can be twice or more than that of the conventional example, thereby improving the productivity of the winding process and reducing the size.・ Lightening is possible.

In actual use, in the case of a coil having a structure as shown in FIGS. 2 and 3, the surface of the enamel film is rubbed with a wire guide or a bobbin flange on the wire running path during coil winding. The thin part of the film occurs partially, or the enamel wire is elongated by the tension at the time of winding,
The film tends to be thinner than the enamel wire film before winding. Therefore, the thickness of the enamel wire coating is generally designed to have a margin with respect to the life limit. The test results shown in FIG. 6 are values obtained when a coil is made so that a large line voltage is applied to cause destruction in a short time. In an actual product design, the maximum voltage and minimum voltage parts It is common to design so as not to touch. In a conventional coil, for example, the line-to-line coating thickness is 80 μm.
In this case, the maximum potential difference between the wires is designed not to exceed 800 V _pp (10 V _pp per 1 μm) (However, according to this standard, as described above, a conventional polyurethane enamel wire is used and an epoxy resin is used. In the case of a flyback transformer insulated by the above, a product failure has occurred in the market, while a flyback transformer insulated with a silicone resin using a conventional polyurethane enamel wire has not failed.)

As is clear from the comparison between the life curves A and C in FIG. 6, the enamel film thickness of the modified polyurethane enameled wire according to the first embodiment of the present invention is 10 μm.
(The line coating thickness is 20 μm) and the case where the line coating thickness is 80 μm insulated with the conventional silicone resin has the same level of life. If the flyback transformer has the same structure, the design criteria will not change in this case.
The modified polyurethane enameled wire of the flyback transformer according to the first embodiment of the present invention has a maximum potential difference between the wires of 800 V _pp . Therefore, when the enamel film thickness is 10 μm (inter-layer film thickness is 20 μm), the maximum potential difference between lines allowed by the design standard of the flyback transformer according to the first embodiment of the present invention is 4 μm per μm.
It means 0V _pp .

However, as described above, the enamel film thickness is preferably 15 μm in consideration of various stresses applied to the enamel wire during production. Therefore, in this case, the maximum potential difference between the lines allowed by the design standard is 2 per μm.
7V _pp .

[0092] Generally, the criterion relating to the life test and the criterion at the product design level are different. In the description of the life curve A of FIG. 6 relating to the life test, even if the maximum potential difference between the lines is 75 V _pp per 1 μm, the life is the same level as that of the case of the conventional line film thickness of 80 μm insulated with a silicone resin. However, at the product design level, a further constant safety factor is required. That is, a transformer or a coil device which may cause a fire in the event of a failure or cause serious damage to society due to the failure requires a certain margin. Therefore, in consideration of cost and reliability, the maximum potential difference between the modified polyurethane enameled wires of the flyback transformer according to the first embodiment of the present invention is 20 to 40 V _pp per 1 μm of the enamel film thickness. Is preferred.

[0093] With the increase in various operation losses due to the increase in the scanning frequency for higher display density and higher image quality of the CRT display monitor, the heat generated by the resin mold type transformer is increased, and it is necessary to cope with the increase in size. I can't get it. Further, in order to improve the usability of the CRT display monitor even slightly, the size of the cabinet is rapidly reduced, the temperature inside the device is rapidly increased, the operation at a high ambient temperature is forced, and the failure of the resin mold type transformer tends to increase. A number of problems have arisen. According to the flyback transformer according to the first embodiment of the present invention,
Many problems facing these current flyback transformers can be solved.

Conventionally, it has been very difficult to provide a li-back transformer that is environmentally friendly and has a manufacturing method and configuration that satisfies both the customer's life guarantee requirement and price reduction requirement. According to the first embodiment of the present invention, it is possible to provide a flyback transformer capable of simultaneously satisfying these various requirements.

(Second Embodiment) Next, a description will be given of a second embodiment in which the excellent life characteristics are utilized to pursue the possibility of reducing the size of the flyback transformer.

In recent years, it has become possible to receive television broadcasts 24 hours a day by increasing the number of satellite broadcasting channels and starting digital multi-channel broadcasting, and there is an opportunity for television receivers to operate continuously for a long time. Is increasing. In the case of a CRT display monitor, demand for individuals combined with a desktop personal computer is also increasing. However, as the screen becomes larger, demand for corporations as terminal equipment for large computers and CAD / CAM systems increases. Used in large proportions.

[0097] When used in a lease contract,
When the life of T is reached, only the CRT is repressed, and the other parts are continuously used. Therefore, the life of the flyback transformer is required to be 50,000 hours or more.

Therefore, in the second embodiment of the present invention, miniaturization was studied based on the temperature difference at 50,000 hours of the estimated life curve B in FIG. In the case of the configuration of the present invention and in the case of the conventional example where there is no market failure due to insulation deterioration,
Since the temperature difference at the estimated life of 50,000 hours is less than about 10 ° C., a flyback transformer having a core cross-sectional area (volume) of about 60% was made based on a conventional flyback transformer.

In the flyback transformer according to the second embodiment, the core material is the same as the conventional one, and the core diameter is reduced and the enamel film thickness of the modified polyurethane enameled wire (CPW-H) is reduced. (4)
(0 μm → 15 μm), the dimensions related to the low-voltage coil bobbin 2, the high-voltage coil bobbin 4, and the like were reduced. The copper wire diameter of the coil and the core gap are the same for both samples, and the number of windings of the primary coil and the high voltage side coil is 1.23 times that of the conventional example in order to match the inductance of the primary coil with the conventional example. Was used.

The flyback transformer for measuring the coil temperature rise is described in the second embodiment of the present invention.
In the conventional example, samples in which thermocouples were respectively inserted into the winding grooves 21 to 28 of the primary coil were prepared, and these flyback transformers were attached to the circuit of FIG.
Operating under the conditions shown in Table 6, the temperature rise of the coil was examined. Table 6 shows the results.

[0101]

[Table 6] This result indicates that the core cross-sectional area (volume) is about 40%
In a flyback transformer in which the size is reduced and the size of each part is reduced in accordance with the ratio, the temperature rise value from the conventional example is about 8 ° C. at the peak portion, and this size is reduced from the data of the conventional example. This also shows that the flyback transformer according to the second embodiment of the present invention has a sufficient reliability.

The modified polyurethane enameled wire (CPW-
Considering that the heat resistance and solvent resistance of H) due to the improved heat resistance and crosslinking density of H) are outstandingly superior to those of conventional heat-resistant polyurethane enamel wires for flyback transformers (UEW-FT and VOUEWB). In addition, operation at high temperatures is possible, and there is a possibility that further miniaturization can be achieved.

In the data shown in Table 6, the temperature rise value of each winding groove of the low voltage side coil tends to be low at the winding start side of the high voltage side coil and high at the winding end side. This is similar to the measured flyback transformer
When the high-voltage side coil is used as a laminated coil, the generated pulse voltage is the lowest at the beginning of the high-voltage side coil and the highest at the end of the high-side coil, so the potential difference between the low-voltage side coil and the high-voltage side coil is high This is because it becomes larger as the coil moves from the winding start side to the winding end side, and is greatly affected by dielectric loss.

According to the flyback transformer according to the second embodiment of the present invention, it is easy to reduce the size of the flyback transformer. Accordingly, the heat generated by the resin mold type transformer is increased due to an increase in various operation losses due to an increase in the display frequency of the CRT display monitor and an increase in the scanning frequency for higher image quality. It gives a great solution to the problem of not being.

On the other hand, in order to improve the usability of the CRT display monitor even slightly, it is required that the cabinet be further reduced in size, and the temperature inside the device is steadily increasing. For this reason, the flyback transformer is forced to operate at a high ambient temperature, and the failure tends to increase. The flyback transformer according to the second embodiment of the present invention has good heat resistance and a long service life, and can solve various problems associated with these flyback transformers.

Further, it is possible to provide a flyback transformer that has an environment-friendly manufacturing method and configuration and that satisfies both the customer's life guarantee request and price reduction request.

(Third Embodiment) FIGS. 7 and 8 are sectional views showing a schematic structure of an ignition coil for an internal combustion engine according to a third embodiment of the present invention. In the ignition coil for an internal combustion engine shown in FIG.
4, a modified polyurethane enameled wire is wound. A secondary bobbin 86 is fitted on the outside of the primary coil 83, and the secondary coil 85 is formed by dividing and winding a modified polyurethane enamel wire in a winding groove between flanges provided on the secondary bobbin 86. The core 110 is inserted from both sides of the through hole of the primary bobbin 84 to form a closed magnetic path.

Although not shown, the core 110 is covered with a core cover, and the core cover is made of a flexible P.
It is molded with a resin such as P. The core cover has a wire holder 87 for holding each coil wire pulled out from both ends of the primary coil 83.
Are formed integrally (in FIG. 7, the wire holder 8 is formed).
7 only). Terminal holders 88 are respectively provided on the flanges at both ends of the secondary bobbin 86, and a secondary terminal is mounted on each terminal holder 88. As shown in FIG. 7, a socket portion 141 is formed in the secondary terminal, and a plug portion 151 of the secondary terminal pin 89 is inserted into the socket portion 141 so that an electrical connection between the two can be obtained. It has become.

These components are housed in a coil case 82, and the coil case 82 is filled (potted) with a liquid epoxy-based resin composition for casting 8 and subjected to insulation treatment. FIG. 8 is a view showing a state where the epoxy-based resin composition for casting 8 is filled in the coil case 82. Usually, on the inner wall of the coil case 82, a marking projection or the like for injecting the liquid epoxy-based casting resin composition 8 is provided. The epoxy resin composition 8 is injected, and the epoxy-based casting resin composition 8 is filled (potted) to a certain level as shown in FIG.

Note that, as shown in FIG.
, A primary terminal coupler 90 is integrally molded. A primary terminal pin 91 is provided inside the primary terminal coupler 90, and each primary terminal pin 91 has a terminal plate 9.
2 are connected. The terminal plate 92 is connected to the primary coil 83 via each coil wire locked in the wire holder 87.

The surface of the cylindrical portion of the primary bobbin 84 is shown in FIG.
A winding groove partitioned by a plurality of flanges similar to (a) is provided. At one end of the cylindrical portion of the primary bobbin 84, a plurality of terminal blocks for fixing a plurality of terminals for connecting the primary coil 83 to an external circuit and a fitting portion for fitting the coil case 82 are provided. You may. A through hole for inserting the core 110 is provided inside the cylindrical portion 20 of the primary bobbin 84. To allocate the winding groove of the primary coil 83,
Although there are various combinations, they are determined in consideration of the performance, reliability, productivity, and the like of the ignition coil.

The winding state of the secondary coil 85 of the ignition coil is substantially the same as the sectional view shown in FIG. 3A, in which the modified polyurethane enameled wire is divided into a plurality of concave grooves formed between the flanges. I'm winding. The secondary coil 8 thus divided and wound
In the case of No. 5, the modified polyurethane enameled wire is randomly wound in each groove, and the potential difference between the modified polyurethane enameled wires is as large as several hundred _Vpp or more in consideration of winding variation. Therefore, a thick modified polyurethane enamel wire having a thickness of about 10 to 15 μm is used.

The modified polyurethane enamel wire used in the ignition coil for an internal combustion engine according to the third embodiment of the present invention is made of a modified polyurethane enamel paint 61 which is easy to solder as shown in FIG. It may be a modified polyurethane enameled wire coated and baked to the copper wire 62 to a predetermined thickness. The thickness of the modified polyurethane enamel wire film and the thickness of the copper wire to be used may be selected according to the required withstand voltage and current capacity.

The heat resistance life characteristic of the ignition coil for an internal combustion engine according to the third embodiment of the present invention when impregnated and molded with an epoxy resin composition for casting is about 1/4 that of the conventional enamel film. With the thickness, a life characteristic equivalent to that obtained by impregnating and molding with a conventional expensive silicone-based casting resin composition can be obtained, and the production cost can be reduced. Further, the reliability of the ignition coil for an internal combustion engine at the time of high temperature operation can be greatly improved, and the size and weight can be reduced.

Further, according to the ignition coil for an internal combustion engine according to the third embodiment of the present invention, the failure of the ignition coil can be avoided even in a situation where operation at a high ambient temperature is forced. In particular, it is possible to provide an ignition coil with an environment-friendly manufacturing method and configuration. Further, it is possible to provide an ignition coil which can satisfy both the customer's life guarantee request and price reduction request.

(Other Embodiments) As described above, the present invention has been described with reference to the first to third embodiments.
The discussion and drawings that form part of this disclosure should not be understood as limiting the invention. From this disclosure, various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art.

In the first to third embodiments, the flyback transformer for generating a high voltage applied to the cathode ray tube (CRT) and the ignition coil for the internal combustion engine have been described. The coil is not limited to a transformer and an ignition coil, but may be a coil such as a large-sized molded transformer as a heavy electric equipment. In any case, it will be apparent from the above description that the present invention is applicable to any resin-molded transformer impregnated and / or molded with an epoxy-based resin composition for casting.

Further, in the present invention, the configuration of the coil, the number of coils, the shape of the core, the thickness of the enameled wire and the thickness of the enamel film may be selected according to the specifications of each resin-molded transformer.

Further, an enamel coating layer may be formed by applying a coating of a copolymer polyamide resin on the upper layer of the modified polyurethane enameled wire and baking. Furthermore, the shape of the case of the resin mold type transformer, the epoxy-based resin composition for casting, and the like are not limited to the above-described first to third embodiments, and may be appropriately selected, and the operation and effect may be improved. The same applies exactly the same.

As described above, it should be understood that the present invention includes various embodiments and the like not described herein. Accordingly, the present invention is limited only by the matters specifying the invention according to the claims that are reasonable from this disclosure.

[0121]

According to the present invention, it is possible to remarkably improve the wet heat resistance, the solvent resistance, the high temperature solder bath immersion peeling property and the like required during the production of a resin mold type transformer or operation in a market.

Further, according to the present invention, the epoxy-based resin composition for casting has a non-blooming composition in which a metal hydrate such as hydrated alumina is used as the main flame-retardant. It can be replaced with a system-based epoxy-based resin composition for casting without deteriorating the reliability, so that a resin-molded transformer can be provided with an environment-friendly method and configuration.

Further, according to the present invention, the heat-resistant life characteristics when impregnated and molded with the epoxy-based resin composition for casting are determined to be about 1/4 of the thickness of the conventional enamel film, and to increase the cost of the silicone-based resin. The same life characteristics as when impregnated and molded with the casting resin composition are obtained, and the production cost is reduced.

Further, according to the present invention, it is possible to secure heat resistance,
The reliability at the time of high temperature operation can be greatly improved, and the size and weight can be reduced. In particular, in the case of a split-winding high-voltage coil to which a large line voltage is applied due to its structure, an even greater effect is exhibited.

Further, according to the present invention, it is possible to provide a resin mold type transformer suitable for high frequency applications.

Further, according to the present invention, it is possible to solve the problems of the resin mold type transformer due to the increase in various operation losses accompanying the increase in the frequency of the electronic equipment and the increase in the heat generation of the resin mold type transformer. I can do it.

Further, according to the present invention, it is possible to provide a resin-molded transformer which satisfies both the customer's life guarantee request and price reduction request.

As described above, the present invention has great industrial value.

[Brief description of the drawings]

FIG. 1 (a) is a partial cross-sectional side view of a flyback transformer according to a first embodiment of the present invention, and FIG. 1 (b) is a modification used for the flyback transformer shown in FIG. 1 (a). It is sectional drawing of a polyurethane enameled wire (CPW-H).

FIG. 2A is a perspective view of a low-voltage side coil of the flyback transformer according to the first embodiment of the present invention.
FIG. 2B is a cross-sectional view illustrating a winding state of a high-voltage side coil of the flyback transformer according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing another form of the high-voltage side coil of the flyback transformer according to the first embodiment of the present invention.

FIG. 4 is a modified polyurethane enameled wire (CPW) used for a flyback transformer according to the first embodiment of the present invention.
-H) and conventional polyurethane enameled wire (UEW-H)
FIG. 5 is a diagram showing a degree of deterioration of an AC breakdown voltage due to the epoxy compound of FIG.

FIG. 5 is a perspective view showing a low voltage side coil for a heat resistance life test of the flyback transformer according to the first embodiment of the present invention.

FIG. 6 is a diagram showing the enamel film thickness and the heat-resistant life characteristics of a modified polyurethane enameled wire (CPW-H) used for a flyback transformer in comparison with the conventional technology.

FIG. 7 is a sectional view showing a schematic structure of an ignition coil for an internal combustion engine according to a third embodiment of the present invention.

8 is a sectional view showing a state in which the ignition coil for an internal combustion engine shown in FIG. 7 is filled (potted) with an epoxy-based resin composition for casting.

FIG. 9 is a partial cross-sectional side view of a conventional flyback transformer.

FIG. 10 is an operation circuit example of a flyback transformer.

FIG. 11 is a perspective view of a conventional low voltage side coil.

FIG. 12 is an enlarged sectional view of a conventional low voltage side coil.

FIG. 13 is a sectional view showing a winding state of a conventional high voltage side coil.

FIG. 14 shows a conventional general polyurethane enameled wire (U
EW) is a sectional view.

FIG. 15 is a sectional view showing another embodiment of the conventional high voltage side coil.

FIG. 16 is a perspective view of a conventional low voltage side coil for a heat resistance life test.

FIG. 17 is a circuit diagram of a heat resistance life test circuit for an enameled wire.

FIG. 18 is a view showing the difference in the heat-resistant life characteristics of a conventional polyurethane enameled wire (UEW) depending on the type of the resin composition for casting.

FIG. 19 is a diagram showing a degree of deterioration of an AC breakdown voltage of a polyurethane enameled wire (UEW) due to an epoxy compound.

[Explanation of symbols]

1, 71 Low voltage side coil 1a Primary side coil 1b, 1c, 1d, 1e Tertiary side coil 2 Plastic bobbin (low voltage bobbin) 2a Through hole 2b Terminal block 2c Fitting part 2d Convex part 3, 45, 72, 74 High voltage Side coil 3a Coil body (first-layer coil) 3b Coil body (second-layer coil) 3c Coil body (third-layer coil) 3d Coil body (fourth-layer coil) 4 Plastic bobbin (high-voltage bobbin) 5 High-voltage diode 6 Focus pack 7 Case 8 Resin composition 9,10,110 Core 11,73 Flyback transformer 12 Gap spacer 20 Tubular part 20a, 20b, 39 Flange 21,22, ..., 28 Winding groove 29,29a, 29b, 29c , 29d terminal 30 polyurethane enamel wire 31 copper wire 32 polyurethane enamel film 37 interlayer insulation film 38 bobbin 40 concave groove 41 high voltage side coil winding part 42 concave part 43 hollow part 50, 64 negative electrode 51, 63 test coil bobbin 52, 65 positive electrode 53, 66 test coil 60 modified polyurethane enameled wire 61 modified polyurethane enamel Coating 62 Conductor 81 Coil base 82 Coil case 83 Primary coil 84 Primary bobbin 85 Secondary coil 86 Secondary bobbin 87 Wire holder 89 Secondary terminal pin 90 Primary terminal coupler 91 Primary terminal pin 92 Terminal plate 93 Boss 141 Socket part 151 Plug part T ₁ horizontal drive transformer _Tr horizontal output transistor D _d damper diode C _o resonance capacitor C _s DC cut capacitor L _d dummy yoke B ₁ power supply

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 12, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

The flyback transformer 11 is mounted on a circuit as shown in FIG. In FIG. 10, T ₁ is a horizontal drive transformer, _Tr is a horizontal output transistor, D _d is a damper diode, and C _o.
Is a resonance capacitor, C _s is a DC cut capacitor, L _d
Denotes a dummy yoke (choke coil), and 11 denotes a flyback transformer. The collector of the horizontal output transistor T _r, the primary side coil of the flyback transformer 11 1
a is connected to one end. The other end of the primary coil 1a is fed a voltage is connected to the power supply B _1.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

FIG. 12 shows a cross section (AA cross section) of a main part of the low voltage side coil 1 shown in FIG. 11B. In FIG. 12, a coil 1b is wound around the winding grooves 21 and 22, and an output side (850/1000 V _pp ) is provided around the winding groove 21.
The winding is started from the side, 1/2 to 2/3 of the whole is wound, the remaining 1/2 to 1/3 is wound around the winding groove 22, and the end of the winding is
It is drawn to. The coil 1c is connected to the primary side coil 1 in order to match the output fluctuations of the high voltage side coil 3 and the coil 1c.
It is wound on the coil 1b of the winding groove 22 so as to be loosely coupled with a. Further, a coil 1e having a relatively small potential difference is wound thereon. The coil 1d is wound around the winding groove 24 because it must be tightly coupled with the primary coil 1a in order to prevent the phase deviation from the collector pulse and the waveform shape from shifting as much as possible. Then, the coil 1a is divided into winding grooves 23, 24, 26, 27, and 28 and wound on the coil 1d in order from the lowest voltage. Winding groove 25
Is a winding groove corresponding to the position of the gap spacer inserted into the abutting surface of the core, so that the coil is generally not wound in order to prevent heat generation of the coil due to leakage magnetic flux. The winding of the primary coil 1a around the winding grooves 23 to 28 in this manner makes the degree of coupling with the high-voltage coil 3 as tight as possible.
This is because the internal impedance of the high-voltage power supply is reduced, the heat radiation of the coil 1a is improved, and the temperature rise of the low-voltage side coil is suppressed low.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

FIG. 15 shows a conventional flyback transformer 1.
It is sectional drawing which shows the other example of a structure of the 1 high voltage side (secondary side) coil. In FIG. 15A, reference numeral 38 denotes a plurality of flanges 39.
High voltage side (secondary side) coil winding part 41 in which the polyurethane enamel wire 30 is wound around the plurality of concave grooves 40 formed by the above, and a high voltage diode disposed between the high voltage side coil winding part 41 5 is a hollow plastic bobbin provided with a concave portion 42 for accommodating the plastic bobbin 2. The plastic bobbin 2 is inserted into the hollow portion 43. FIG.
FIG. 15B shows the high voltage side (secondary side) coil 4 shown in FIG.
It is sectional drawing which shows the winding state of 5 in detail. FIG. 15 (b)
As shown in FIG. 14, in each of the grooves 40, a plurality of the polyurethane enamel wires 30 shown in FIG. The coil winding part 41 is formed.
A high voltage diode 5 is connected between the high voltage side coil winding portions 41 and 41 so as to have a polarity in which a current flows in the forward direction. The structure shown in FIG. 15B is obtained by dividing a plurality of layers of the coil bodies 3a to 3d shown in FIG. A high voltage side coil 45 is formed. Therefore, when the circuit is operated using the circuit shown in FIG. 10, it operates in the same manner as the case of the stacked high-voltage side coil 3 shown in FIG. However, in the case of the high-voltage side (secondary side) coil divided and wound as shown in FIG. 15, about several hundred windings are applied to each winding groove, and it is difficult to reliably form the aligned winding. Because of the random winding, in the case of the worst case including the collapse, an AC potential difference of several hundred volts or more is applied between the polyurethane enamel wires 30, and the thickness of the polyurethane enamel film 32 is 15 to
Thick polyurethane enamel wire 30 with a coating of about 25 μm
Is used.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

These samples were attached to a polyurethane enamel wire heat resistance life test circuit shown in FIG. 17 and tested under predetermined conditions. In FIG. 17, T ₁ is a horizontal drive transformer,
_Tr is a horizontal output transistor, D _d is a damper diode, _Co is a resonance capacitor, L is a choke coil, 53
/ 66 life of heat resistance test coil, B ₁ is a driving power source. As shown in FIG. 17, the terminal 29a is grounded,
To 9c, a television pulse voltage having a frequency of 82.0 kHz, a retrace time of 2.5 μS, and a pulse peak value of 1500 V _pp was applied.
Continuous power application was performed in an atmosphere at an ambient temperature of 130 ° C., 140 ° C., and 150 ° C. until breakdown.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction contents]

[0041]

[Table 2] Therefore, the SP value is the closest to that of the polyurethane enamel paint.
To 50 parts by weight of diethylene glycol diglycidyl ether (Epiol E-1 manufactured by NOF Corporation)
00) in a 90 ° C. solution, a polyurethane enamel wire having an average thickness of a polyurethane enamel film of 40 μm (used by our company)
0.26 VOUEWB) was immersed in a twisted pair (two twisted) sample prepared according to JIS C3203 for a predetermined time, and then the AC withstand voltage breakdown level was examined. The results are shown in FIG. This result shows that the immersion time is only 10
This indicates that the breakdown voltage is reduced to about half in 30 minutes and about 1/4 in 30 minutes.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

Accordingly, SP of the modified polyurethane enamel film used for the modified polyurethane enamel wire of the present invention
The value is preferably different from that of the epoxy-based casting resin composition. By the way, in order to prevent environmental pollution, it is better not to use a flame retardant such as a halogen flame retardant or an antimony compound in the plastic member or the epoxy resin composition for casting. Therefore, the epoxy resin composition for casting of the present invention preferably contains a metal hydrate such as hydrated alumina powder as a main component of the flame retardant. The epoxy resin composition for casting of the present invention preferably contains diethylene glycol diglycidyl ether as a main component of the diluent. SP of diethylene glycol diglycidyl ether
Considering that the value is 9.81, the SP value of the modified polyurethane enamel film used for the modified polyurethane enamel wire of the present invention is preferably approximately 10.5 to 10.85. The SP value is preferably larger than the SP value of the epoxy-based resin composition for casting. However, in consideration of the case where the epoxy resin is also used for the epoxy-based resin composition for bromide-based casting, a diluent (dibromophenol monoglycidyl ether) is used. ) SP value 1
This is because it is better to be smaller than 0.9. Specifically, S
In order to increase the P value, the imide group, the aromatic ring, and the degree of branching (the state of the three-dimensional structure and the crosslink density) in the epoxy resin composition for casting may be increased.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0075

[Correction method] Change

[Correction contents]

In order to confirm these results in more detail, a conventional polyurethane enameled wire (φ0.26 V
0UEWB) in a 90 ° C. solution of diethylene glycol diglycidyl ether (Epiol E-100, manufactured by NOF CORPORATION), a violently attacked enamel film, of the modified polyurethane enameled wire used in the present invention. 40 μm, 15 μm, 10 μm (φ0.26 special 0CPW-H, 1CPW-H, manufactured by Hanashima Electric Cable Co., Ltd.)
2CPW-H) and a conventional heat-resistant polyurethane enameled wire for flyback transformer (imide-modified polyurethane enameled wire) having an average enamel coating thickness of 40 μm and 15 μm (φ0.26 special 0UEW-FT manufactured by Hanashima Electric Cable Co., Ltd.
1UEW-FT) and a twisted pair (two twisted) sample prepared according to JIS C3203 are immersed for a predetermined time,
Thereafter, the AC withstand voltage breakdown level was examined, and the results are shown in FIG. The result is a heat resistant polyurethane enameled wire for a conventional flyback transformer (φ0.26, specially 0UEW).
-FT, 1UEW-FT), the withstand voltage breakdown value is reduced to less than half when the immersion time is only 10 minutes, whereas the modified polyurethane enameled wire (φ0.26, special 0, 1, 2CPW-H) used in the present invention is used. ) Has a very small reduction rate of the withstand voltage breakdown value, and the average enamel film thickness is 10 μm (φ0.
26 2CPW-H), when the immersion time is 30 minutes, a very large improvement effect that the withstand voltage value is superior to that of the conventional example having an average enamel film thickness of 40 μm (φ0.26, especially 0UEW-FT) is shown. ing.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0085

[Correction method] Change

[Correction contents]

The life curve B indicates that the average enamel film thickness of the modified polyurethane enameled wire 60 was 10 μm
The estimated life characteristics are shown in the case of using (φ0.26 2CPW-H) and using, as the negative electrode 64, a solder plated wire obtained by peeling the enamel coating of a φ0.26 enamel wire by soldering. In this enamel wire heat life test,
One of the wires (the wire on the minus electrode 64 side) is a bare wire from which the enamel coating has been peeled off by soldering.
m. The life curve A shows that the average enamel film thickness of the modified polyurethane enameled wire 60 is 10 μm (φ0.26 2CPW-H) on the negative electrode 64 and the positive electrode 65.
The following shows the estimated life characteristics in the case of using the above. Life curve A
In the heat resistance life test for enameled wire shown in (1), the enamel coating is present on both the wire on the minus electrode 64 side and the wire on the plus electrode 65 side, so that the film thickness between the wires is 20 μm. FIG.
(Lifetime curves C and D) are plotted in a superimposed manner. Compared with the results of the conventional example, the estimated life characteristics (lifetime curve C) obtained by performing the insulation treatment with the silicone-based casting resin composition of the conventional example, and the insulation treatment with the non-bloomed epoxy-based casting resin composition were performed. And the estimated life characteristic (life curve A) of the flyback transformer according to the first embodiment of the present invention shows almost the same life curve. As described above, the life curve C of the conventional example is an estimated life characteristic in which there is no short-circuit failure due to insulation deterioration of the enameled wire in the market.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 008

[Correction method] Change

[Correction contents]

This means that the thickness of the enamel film is 40 μm in the case of the conventional example using an expensive silicone-based casting resin composition (interline film thickness 80 μm ... 18.75 V _pp per 1 μm film thickness). Is required, whereas the first of the present invention
In the case of the flyback transformer according to the embodiment of the present invention, it is possible to use an inexpensive non-bloom epoxy resin composition for casting based on 10 μm (line-to-line film thickness 20 μm...
At 75.00 Vp _{- p} ). In addition, in the case of the flyback transformer according to the first embodiment of the present invention, the enamel film thickness between lines is 10
Estimated life characteristics of μm (150 V _pp per 1 μm of film thickness) (see life curve B in FIG. 6) and conventional enamel film thickness of 40 μm (interline film thickness of 80 μm... 18.75 V _{p -p} per 1 μm of film thickness) The life expectancy characteristics (see life curve D in FIG. 18) when insulation treatment is performed with the epoxy-based resin composition for casting using a polyurethane enameled wire (see FIG. 18) show substantially the same estimated heat resistance life characteristics.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4 is a modified polyurethane enameled wire (CPW) used for a flyback transformer according to the first embodiment of the present invention.
-H) and conventional polyurethane enameled wire (UEW-F)
It is a figure which shows the deterioration degree of AC breakdown voltage by the epoxy compound of T).

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01F 27/32 H01F 19/04 Q // H01F 38/12 H04N 3/195 H01F 31/00 501J 501C (72) Inventor Kazuo Takagaki 3-12-12 Moriyacho, Kanagawa-ku, Kanagawa-ku, Japan Within Victor Company of Japan (72) Takahiko Hanada 108-8 Matsubara, Sayamagahara, Iruma City, Saitama

Claims (6)

[Claims] 1. A stabilized isocyanate is compounded in a low pressure bobbin with a polyesterimide resin obtained by reacting an imide acid formed by reacting an excess of tricarboxylic acid and a diamine on a conductor with a polyhydric alcohol on a conductor. A low-voltage side coil wound using a modified polyurethane enameled wire formed by baking a modified polyurethane enameled film, and a high-pressure side coil wound on a high-pressure bobbin using the modified polyurethane enameled wire. A transformer comprising at least: a low-pressure side coil and a high-pressure side coil impregnated with an epoxy-based resin composition for casting and / or molded. 2. The modified polyurethane enameled wire adjacent to the high-pressure side coil has a line voltage of 20 V _pp or more per 1 μm of the thickness of the modified polyurethane enameled film. The transformer of claim 1. 3. The modified polyurethane enameled wire adjacent to the modified polyurethane enameled wire in the low voltage side coil has a line voltage of 20 V _pp or more per 1 μm of the thickness of the modified polyurethane enameled film. The transformer of claim 1. 4. The transformer according to claim 1, wherein the epoxy resin composition contains a metal hydrate as a main component of the flame retardant. 5. The transformer according to claim 1, wherein the epoxy resin composition for casting contains diethylene glycol diglycidyl ether as a main component of a diluent. 6. The transformer according to claim 5, wherein the modified polyurethane enamel coating has a solubility parameter of 10.5 to 10.85.