JPH01220305A - Insulated wire - Google Patents

Abstract

PURPOSE:To obtain an insulated wire having an excellent electric and mechanical characteristic by forming the coat baking layer of an insulating varnish on the outer periphery of a conductor, and forming the insulating coat layer in which a synthetic resin fine particle is made to fusedly harden by an electrostatic flow dipping method on the outer side of the coat baking layer. CONSTITUTION:The straight angle core wire W' delivered from a core wire supply drum 6 is applied with an enamel varnish on its outer periphery by passing an application tank 1 and a die 2, and hardened with a baking furnace 3. A lower side coated layer is formed by plural repetitions of this process as required. Then a synthetic resin fine particle is adhered to the surface of the lower side coated layer within a fine particle applying chamber 4, after that the synthetic resin fine particle is fusedly hardened by passing a heating furnace 5, and a straight angle insulated wire W to which the upper side coated layer is formed is manufactured. An insulated wire having an excellent electric and mechanical characteristic of electric breakdown voltage and wear resistance etc., and excellent heat resistance can be obtained by thus providing the coat baking layer of an insulating varnish between an insulating layer and a conductor by a fine particle applying method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an insulated wire, and more particularly to improvement of an insulated wire by an electrostatic dynamic dipping method.

[Conventional technology] In recent years, methods for manufacturing insulated wires using powder coating methods have been attracting attention from the viewpoints of pollution-free, resource-saving, and energy-saving methods.Among these, the electrostatic dynamic dipping method is a method with high coating efficiency. is attracting attention, especially in the field of insulated wire manufacturing.

In this method, for example, charged synthetic resin powder is fluidized by dry air passing through a perforated plate placed below to form a fluidized bed, and a metal conductor is filled with the synthetic resin powder above this fluidized bed. This is a method in which synthetic resin powder is electrostatically attached to the surface through a powder coating chamber, and then the attached synthetic resin powder is heated and fused and cured to form a film. Usually, metal conductors are powder coated. A method is adopted in which it passes horizontally into the room.

[Problems to be Solved by the Invention] However, insulated wires manufactured by such a method have the disadvantage that a coating of uniform thickness cannot be obtained over the entire circumference of the metal conductor, and therefore the dielectric breakdown voltage is low. .

In particular, when manufacturing rectangular dislocation stranded wires, the dielectric breakdown voltage, heat resistance, and abrasion resistance are improved compared to the case of using conventional rectangular wires coated with polyvinyl formal resin (PVF) or other coated baking layers. There was a problem in that it was difficult to manufacture the coil to a predetermined size at the time of coil forming because the finished dimensions were difficult to stabilize.

The present invention was made in order to solve these problems, and it has electrical properties, especially high dielectric breakdown voltage, and excellent heat resistance and abrasion resistance. The purpose is to provide insulated wires.

[Means for Solving the Problems] The present invention provides an insulating coating in which a coated and baked layer of insulating paint is formed on the outer periphery of a conductor, and synthetic resin powder is fused and hardened on the outside by an electrostatic dynamic dipping method. It is characterized by forming a layer.

The thickness of the coated and baked layer of the above insulating paint is preferably in the range of 3 to 30% of the thickness of the insulating coating layer formed by electrostatic dynamic dipping. The reason for this is that if the above film thickness is less than 3%, the overall dimensional accuracy will not improve, and no improvement in dielectric breakdown voltage, heat resistance, etc. will be observed.On the other hand, if it exceeds 30%, synthetic resin powder This is because it causes problems with electrostatic adhesion to the body.

As the insulating paint, enamel varnishes such as formal resin, polyester resin, polyimide resin, polyamideimide resin, polyimide hydantoin resin, etc. can be used.

[Function] According to experiments conducted by the present inventors, it has been determined that the electrostatic adhesion of powder is very easily affected by the surface properties of the conductor, such as dirt. In the insulated wire of the present invention, the synthetic resin powder is applied on the outside of the thin coated and baked layer of insulating paint, which improves the precision of finished dimensions, and therefore prevents dielectric breakdown that occurs when there are large variations in coating thickness. Problems such as voltage drop, heat resistance, and wear resistance are solved.

[Example] An embodiment of the present invention will be described below.

The figure schematically shows an apparatus for carrying out the present invention, in which numeral 1 is a coating tank containing enamel varnish, 2 is a die, 3 is a baking furnace, 4 is a powder coating chamber, and 5 is a heating furnace. be.

In the above device, the flat core fed out from the core wire supply drum 6! ! ! W' is coated with enamel varnish on its outer periphery by passing through a coating tank 1 and a die 2, and then hardened in a baking furnace 3, and by repeating this process multiple times as necessary, the lower side is coated with enamel varnish. A coating layer is formed. Next, after synthetic resin powder is attached to the surface in the powder coating chamber 4, the synthetic resin powder is heated and fused and hardened by passing through the heating furnace 5 to form an upper coating layer. The formed rectangular insulated wire W is manufactured.

In the figure, numerals 7 and 8 indicate an upper sheave and a lower sheave, respectively, and 9 indicates a winding drum.

2. From the example core wire supply drum. OX 5.0 (11m) rectangular copper wire at a wire speed of 4. Pays out at h/min, TV25307
The lower insulating coating was formed by passing through a coating tank containing Polyester FES (trade name, manufactured by Toshiba Chemical Co., Ltd.) and repeating the process of heating and curing in a baking oven.

The furnace temperatures in this baking process are 380°C and 350°C and 350°C and 250°C at the bottom, center, and top of the furnace, respectively.

On the other hand, synthetic resin powder (
ECP2O1! ;Sumitomo Durez Co., Ltd. epoxy resin powder name) was applied to a 125J perforated plate in a painting room with a length of 70c+g.
l! The coating was fluidized by dry air flowing through it at a flow rate of 1/min to form a fluidized bed at the bottom of the coating chamber. From this fluidized bed, approximately 10
The above-mentioned wire rod was passed in the horizontal direction over a cm, and the charged synthetic resin powder was adhered to the surface. Next, the rectangular copper wire with synthetic resin powder attached to its surface was heated in a furnace at a temperature of 400 to 450°C.
The synthetic resin powder was inserted into a heating furnace with a furnace length of 3.5 m, and the synthetic resin powder was heat-fused and further cured to form an upper insulating coating. Obtained rectangular insulation m! The various properties of Iil are shown in the table.

Comparative Example An insulating coating layer was formed using only the electrostatic dynamic dipping method under the same conditions as the method for forming the upper insulating coating shown in the Example. The properties of the obtained rectangular insulated wire are shown in the same table.
(Left below) Ratio of the number of times when this example is taken as 100 As is clear from the above explanation, according to the present invention, a coated and baked layer of insulating paint is applied between the insulating layer and the conductor using the powder coating method. By providing this, it is possible to obtain an insulated wire that has excellent electrical and mechanical properties such as dielectric breakdown voltage and abrasion resistance, and also has excellent heat resistance.

[Brief explanation of the drawing]

The figure is a schematic diagram of a manufacturing apparatus used in the present invention. 1......Coating tank 2...Dice 3...Baking furnace 4...Powder coating room 5・・・・・・Heating furnace applicant Showa Cable and Wire Co., Ltd. Representative Patent attorney Sasa Suyama − (and 1 other person)

Claims (2)

[Claims] (1) Form a coated and baked layer of insulating paint on the outer periphery of the conductor,
Synthetic resin powder is fused to the outside using electrostatic dynamic dipping method.
An insulated wire characterized by forming a hardened insulating coating layer. (2) The thickness of the applied baking layer of the insulating paint is 3 to 30% of the thickness of the insulating coating layer of synthetic resin powder (Claim 1)
Insulated wire as described.