JPS5919606B2 - Insulated wire manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 15 The present invention relates to an insulated wire manufacturing apparatus for applying an insulation coating to a core conductor.

Conventional general insulated wire manufacturing equipment mainly consists of an extruder that extrudes and coats a core wire conductor with molten resin.

In addition to this, in order to manufacture insulated wires with a particularly small coating thickness, attempts have been made to use a dipping method and a method in which plastic powder is electrodeposited or electrostatically attached. However, these methods require a baking furnace separate from the means for attaching the plastic powder, resulting in high equipment costs, and the production equipment is complicated and large, making management of the slit 25 complicated. Furthermore, in these methods, the coating thickness is controlled by controlling the take-up speed, voltage, etc. of the core conductor, but these are all difficult to control and it is difficult to obtain a uniform coating thickness. It has also been proposed to heat the core conductor before dipping to melt and coat the plastic powder, but with this method the coating thickness is small and a wide range of coating thicknesses cannot be obtained. An object of the present invention is to provide an insulated wire manufacturing apparatus that can miniaturize the equipment, make it easy to manage, and reduce equipment costs, and that can produce insulated wires with a wide range of coating thicknesses. be.

Another object of the present invention is to provide an insulated wire manufacturing apparatus that can easily control the coating thickness.

Embodiments of the present invention will be described in detail with reference to the drawings.
The figure schematically shows an insulated wire manufacturing apparatus 10 of the present invention, which includes core conductor preheating means 12 provided sequentially at intervals along the running path of the core conductor 1.
, a plastic spraying means 14 and a coating thickness control means 16.

The core conductor preheating means 12 includes a heating coil 18 having a through hole 18a through which the core conductor 1 passes, and the core conductor 1 is preheated to a predetermined temperature by the heating coil 18. The plastic spraying means 14 is provided at a distance from a substantially conical first guide member 22 through which the core conductor 1 is guided and which has a guide tip 20 made of diamond or cemented carbide at its entrance. Water cooling cavity 2
4a and a third guide member 26 attached to the front surface of this second guide member 24 and also having a water cooling cavity 26a and further attached to the front surface of this third guide member 26. A fourth guide member 28 is provided.

A core conductor 1 is provided between the first and second guide members 22 and 24.
A plastic powder passage 30 is formed that gradually inclines radially inward in the direction of movement of the plastic powder passage 30 for pumping the plastic powder so as to spray it onto the outer periphery of the core conductor 1 coming out from the first guide member 22. This plastic powder is therefore adhered to the preheated core conductor 1. A cartridge 34 having a material input port 32 communicating with the plastic powder passage 30 is mounted between the first and second guide members 22 and 24. Second and third guide members 2
4 and 26, the second guide member 24 is provided with a radial annular passage portion 36a and an annular passage portion 36b that gradually inclines inward in the direction of movement of the core conductor 1. A burner 36 having a fuel supply port 36c communicating with the portion is provided.

When a mixed gas of propane gas and oxygen is supplied from the fuel supply port 36c and ignited, a flame is generated at the exit of the annular passage portion 36b, so that the plastic powder attached to the core conductor 1 is melted or a hardening reaction occurs. Then, plastic is welded onto the core conductor 1. In this way, plastic is deposited on the core conductor 1 by the thermal spraying technique to obtain a predetermined insulating coating. Note that cooling water is circulated through the water cooling cavities 24a and 26a to prevent the guide members 22, 24, 26, and 28 and the cartridge 34 from overheating. A cooling medium passage 38 is formed between the third and fourth guide members 26 and 28 for blowing cooling air onto the insulation coating on the core wire conductor 1, and this cooling medium passage is provided in the fourth guide member 28. The cooling medium supply port 38a is connected to the cooling medium supply port 38a.

The coating thickness control means 16 includes a metal plate 40 having a through hole 40a through which the core conductor 1 having an insulating coating is formed, and whose position is adjusted in the axial direction of the core conductor 1.

It is preferable that the through-hole 40a has a tapered shape in which the hole diameter gradually decreases in the direction of movement of the core conductor 1, since the flame is narrowed in the direction of movement of the plastic spraying flame. When the metal plate 40 approaches the plastic spraying means 14, the flame aperture becomes stronger and the coating thickness increases; conversely, as the metal plate 40 moves away from the plastic spraying means 14, the flame aperture weakens and the coating thickness decreases. Become. Incidentally, reference numeral 42 denotes a water cooling pipe that is attached to the front surface of the metal plate 40 in a heat conductive manner to prevent the metal plate 40 from being overheated by the flame of thermal spraying. Next, the operation of the above-mentioned apparatus will be described. The core conductor 1 is preheated by the preheating means 12 and then enters the plastic spraying means 14.

In the plastic spraying means 14, the plastic powder sprayed from the plastic powder passage 30 is adhered to the core conductor 1, and is then melted or heated and hardened by the flame from the burner 36 to form an insulating coating. As previously mentioned, the thickness of this insulating coating is controlled by adjusting the position of metal plate 40 to reduce or limit the flame from burner 36. Incidentally, in order to prevent the plastic powder from being fixed in the apparatus due to thermal melting, it is preferable that the air for pumping the plastic powder be appropriately cooled.
Next, to describe an example of the present invention, the particle size of the coating material is 8.
A thermoplastic high-pressure polyethylene powder having a mesh size of 0 to 90 was used, and a copper conductor having a diameter of 0.65 nm was used as a core conductor. After preheating the conductor to 200 to 240 DEG C., an insulating coating was formed using the apparatus shown in FIG. The metal plate of the coating thickness control means was a brass plate with a thickness of 20 to 30 nm, the taper angle of the through hole was 20 nm, and the distance from the plastic spraying means was about 5 C1. The insulation coating obtained by this device has a thickness of about 400 μ and a good appearance, a dielectric strength of DCl to 1.5K, and good thermal shock resistance, flexibility, and heat deterioration resistance. Ta. In addition, thermosetting epoxy resin powder was used as the coating material, and the preheating temperature of the core conductor was set to 120℃.
Insulating coatings were obtained under exactly the same conditions as above, except that the temperature was ~140°C, and similar good results were obtained.

In the embodiment shown in FIG. 1, the plastic spraying means 14 is annular and the core conductor passes through it, but as shown in FIG. You can also arrange them in According to the present invention, as described above, since the adhesion of plastic powder to the core conductor and the melting or thermosetting can be performed simultaneously, the equipment can be miniaturized and its management is easy, and the coating thickness can be easily controlled. Therefore, it is possible to economically obtain high-quality electric wires having insulation coatings of a wide range of thicknesses.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram of an insulated wire manufacturing apparatus according to the present invention,
Fig. 2 is a system diagram of a modified example of the device of the present invention, and Fig. 3 is a system diagram of a modification of the device of the present invention.
FIG. 3 is a front view of the plastic spraying means shown in the figure; DESCRIPTION OF SYMBOLS 1...Core conductor, 10...Insulated wire manufacturing device, 12...Preheating means, 14...
Plastic spraying means, 16...Coating thickness control means, 30...Plastic powder passage, 36...
...Burner, 40...Metal plate, 40a...
...Through hole.

Claims (1)

[Scope of Claims] 1. Core wire conductor preheating means and plastic spraying means are arranged sequentially along the running path of the core wire conductor, and the plastic spraying means sprays plastic powder onto the outer periphery of the preheated core wire conductor. 1. An insulated wire manufacturing device comprising: a passage for pumping plastic powder to the core conductor; and a burner blowing flame onto the plastic powder on the core conductor. 2. A core conductor preheating means, a plastic spraying means, and a coating thickness control means are arranged in sequence along the running path of the core conductor, and the plastic spraying means sprays plastic powder onto the outer periphery of the preheated core conductor. The coating thickness control means has a through hole through which the core conductor to which the plastic powder is adhered passes, and the coating thickness control means has a through hole through which the core conductor to which the plastic powder is adhered passes. An insulated wire manufacturing device comprising a metal plate whose position is adjusted in the axial direction of the insulated wire. 3. The plastic spraying means is arranged so that the core wire conductor passes through its center.
The insulated wire manufacturing device described in 2. 4. The insulated wire manufacturing apparatus according to claim 2, wherein the plastic spraying means are arranged radially around the core wire conductor. 5. The insulated wire manufacturing apparatus according to claim 2, wherein the through hole has a diameter that decreases in the direction of movement of the core conductor.