JPS5945429B2 - Wire enamel coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an enamel coating device used to apply enamel paint to wire rods.

When applying enamel paint to a wire rod using an enamel coating device, conventionally the wire rod is fed to the enamel coating device filled with enamel paint and the enamel paint is deposited on the wire rod.
Furthermore, this wire is passed through a coating die provided in the apparatus, and the enamel paint applied onto the wire is formed into a coating layer of a predetermined thickness.

The wire coated with the enamel paint in this manner is further fed to a baking furnace, where the coating layer of the enamel paint is baked on the wire, resulting in an enameled wire. Generally, the coating die is maintained in a floating state above the enamel paint so that the wire passes along its central axis, but if the enamel paint has a high viscosity, the coating die will move along with the wire passing through the die due to the adhesive force of the enamel paint. You will no longer be able to move and remain floating. Therefore, the wire deflects the coating layer of the enamel paint applied to the wire without passing over the central axis of the coating die. Furthermore, if the viscosity of the enamel paint filled into the enamel coating device increases further, when the wire passes through the coating die, the friction between the enamel paint adhered to the wire and the coating die will increase, causing the wire to become thinner and even break. I will do it. For this reason, the varnish traditionally used as enamel paint is diluted with organic solvents such as cresol and naphtha to reduce the viscosity of the enamel paint, thereby preventing deflection of the coating layer of the enamel paint, thinning of the wire material, and wire breakage. .

However, since this organic solvent only has the function of diluting the enamel paint, the wire coated with the enamel paint must be stripped of this solvent in a baking oven. The organic solvent is therefore evaporated in the baking oven. In this way, when manufacturing enameled wire using conventional enamel coating equipment, unnecessary organic solvents must be used in the end, and moreover, the organic solvents that evaporate in the furnace and reach a certain concentration are Because it is explosive, it is burned using a catalyst. Therefore, in addition to the organic solvent, a catalyst and energy for combustion treatment of the organic solvent are required, which is uneconomical. In addition, the gas produced by burning organic solvents must be released into the atmosphere, causing air pollution. The object of the present invention is to provide an enamel coating device that can perform the following steps.

The wire rod enamel coating apparatus according to the present invention will be described in detail with reference to the drawings. FIG. The casing 14 is divided into upper and lower halves and has a circular hole 16a in the center for passing the wire 12 through, and a casing 14 which has an outlet 18a for the wire 12 and is fixed to the upper surface of the partition wall 16. The coating die holding member 18 is fitted into the upper half of the coating die holding member 18, and the coating die 20 is aligned with the outlet 18a of the wire rod 12 of the coating die holding member and is held by the holding member 18. Casing 1 partitioned by partition wall 16
The lower half of 4 and inside the coating die 20 contain enamel paint 2.
The wire rod 12 enters the enamel paint 22 through the inlet 14a of the casing 14, and further passes through the coating die 20 to the outlet 18 of the coating die holding member 18.
The enamel paint 22 is extrusion coated by exiting from a. In the present invention, an enamel paint made of a solvent-free varnish or a high-concentration varnish that has not been diluted with an organic solvent is filled into the device at room temperature or heated and melted, and the enamel paint is coated on the wire 12. An enamel paint having a viscosity in the centiboad range is used, and the coating die has a cylindrical wire outlet hole 20a provided at its tip, and a wire introduction hole provided upstream of the wire outlet hole 20a, continuous with the wire outlet hole 20a. It is made of something like 20b.

The length L and diameter d of the cylindrical wire outlet hole 20a are 0.
．． 5d≦L≦5d...The relationship of (1) is satisfied, and the taper angle α of the wire introduction hole 20b is 2 to 1.
00 (see Figure 2). In this way, the enamel paint can be applied to the wire without causing thinning or breakage of the wire or eccentricity of the coating layer of the enamel paint. If the relationship between the length L of the wire outlet hole 20a of the coating die 20 and the diameter d is 5d<L, the viscous friction between the enamel paint attached to the wire and the coating die will increase, causing thinning and breakage of the wire 12. On the other hand, it has been confirmed through experiments that if the relationship between the length L and the diameter d of the wire outlet hole 20a is set to L<0.5d, uneven thickness will occur in the coating layer of the enamel paint applied to the wire. .

Experiments have also shown that if the viscosity of the enamel paint filled into the enamel applicator is lower than 2,000 centiboads, uneven thickness will occur in the coating layer of the enamel paint, while if it is made higher than 20,000 centiboads, thinning and breakage of the wire will occur. Confirmed by. When the conditions of the present invention are met, even if the wire 12 is introduced into the coating die 20 deviating from the central axis of the coating die 20, it passes almost on the central axis of the coating die 20 when passing through the coating die 20.

It is presumed that this is because the enamel paint, which has a uniform pressure inside the coating die 20, applies pressure (aligning force) uniformly to the circumferential surface of the wire rod, causing the wire rod to move toward the central axis of the coating die (Fig. 3). reference). It has been found that the centering force of the enamel paint is greatest when the taper angle α of the wire introduction hole 20b of the coating die 20 is 2 to 100. Next, experimental examples of the present invention are shown below.

In this experiment, a polyester-based varnish with a concentration of 90% fixed form was heated and melted at 170°C and had a viscosity of about 4000 centiboads.
The coating die has a wire outlet hole length L of 1.511, a wire rod introduction hole taper angle α of 8L, and a diameter of 1.041111.
．． 067Bm11.08 Kashimachi 1.10 Four different fins were used. The diameter of the wire is 11l and the wire speed is 30m/
Vl, the baking furnace has an evaporation zone temperature of 400℃ and a hardness zone temperature of 4
Using an electric hot air oven at 50° C., coating and baking were performed four times to produce an enameled wire with a coating layer having a thickness of 40 μm. As a result of this experiment, it was possible to manufacture a high-quality enameled wire with no eccentricity, and the energy consumption and electric power per unit weight of the enameled wire was 0.3 higher than that of the conventional method.
KWH/I<g. According to the present invention, as described above, since the enamel paint made of high concentration or solvent-free varnish can be applied to the wire rod, the enameled wire can be manufactured without using a large amount of organic solvent or organic solvent. In addition, when a highly concentrated varnish is used, the amount of organic solvent evaporated in the furnace is reduced, so the number of times the organic solvent in the furnace is burned with a catalyst can be reduced.On the other hand, when a solvent-free varnish is used, If a high concentration varnish is used, the process of burning the organic solvent can be omitted, and if a highly concentrated varnish is used, the number of applications can be reduced, resulting in lower material costs and energy consumption compared to conventional methods. It is economical.

Furthermore, according to the present invention, air pollution can be effectively prevented because a small amount of organic solvent is used or no organic solvent is required in the production of enameled wire, and furthermore, the coating die is fixed and the enamel paint is applied to the wire. Therefore, a horizontal baking furnace can be used, which has the advantage of improving workability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an enamel coating device of the present invention, FIG. 2 is a longitudinal sectional view of a coating die used in the enamel coating device of the present invention, and FIG. 3 is a longitudinal sectional view of a coating die used in the enamel coating device of the present invention. FIG. 2 is a cross-sectional view showing where the wire passes through. 10... Enamel coating device, 12...
Wire rod, 14...Casing, 16...Partition wall, 18...Coating die holding member, 20...
...Coating die, 20a...Wire rod exit
20b...Introduction of wire rod 22...Enamel paint.

Claims (1)

[Claims] 1. In a wire enamel coating device equipped with a coating die for applying the enamel paint onto a wire filled with enamel paint and continuously passing through the wire, the coating die is provided at its tip and has a length L and a diameter d of 0. A cylindrical wire outlet hole that satisfies the relationship 5d≦L≦5d, and a taper angle α of 2 to 10 that is provided continuously to and upstream of the cylindrical wire outlet hole.
1. A wire rod enamel coating device comprising: a wire rod introduction hole set in the range of 10.degree.