JPS6123608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a preheating furnace together with a baking furnace when baking enameled electric wires, and this preheating furnace is supplied with exhaust heat from the baking furnace or annealing furnace to apply the enamel coating material. The present invention relates to a method of baking an enameled electric wire in which the running wire is preheated in advance.

Baking of enameled wires is generally done using a baking furnace that has a zone for evaporation from below, a curing zone, a cooling zone, etc., and the wire coated with the enamel coating material is run upwards from the bottom of the baking furnace, during which time The solvent in the enamel coating material is evaporated, hardened, and cooled, and this process is repeated several times to obtain the finished product.

However, according to this type of conventional method, the running wire is heated in the evaporation zone of the baking furnace using a built-in heater or hot air to evaporate the solvent in the enamel coating material.
In this case, since the coating material is heated from the outside, it is difficult to rapidly heat the coating material deep inside. If rapid heating is performed, curing occurs only on the surface side of the coating material, and the deep internal solvent The evaporation of the liquid was inhibited, resulting in the formation of bubbles. Therefore, in order to uniformly heat the enamel coating material deep inside, it was necessary to heat it slowly and gently. For this reason, the linear speed of the running wire could not be increased very much, and there was a limit to this, resulting in poor productivity.

The present invention has been made in view of the above-mentioned circumstances, and includes a preheating furnace in addition to the baking furnace, and the preheating furnace is equipped with a preheating furnace that collects waste from the baking furnace or from the annealing furnace used in the wire annealing process. In addition to supplying heat for effective use of energy, the running wire is preheated prior to application of the enamel coating material,
After applying the enamel coating material, the heat stored in the wire immediately starts to evaporate the solvent in the coating material from the inside, and then it is led to a baking oven where it is heated and baked to eliminate bubbles and other problems. This eliminates the occurrence of this problem and greatly improves processing speed.

Hereinafter, one embodiment of the present invention will be explained in detail with reference to the drawings.

In the figure, 1 is a baking furnace, which has an evaporation zone 2, a cure zone 3, a cooling zone 4, etc. from the bottom, and a preheating furnace 5 is provided in the vicinity thereof. In the case of this example, specifically, on the back side of the baking furnace 1, the wall surface from the evaporation zone 2 to the cure zone 3 is made common. That is, the preheating furnace 5 is formed integrally with the baking furnace 1.

On the sides of the baking furnace 1, on the sides of the evaporation zone 2 and cure zone 3, there are branched hot air passages 6 for circulating hot air, and air supply ports 7, 7 for taking in outside air. , an exhaust port 8 for exhaust, etc. are provided. Furthermore, a blower 9 and a solvent combustion catalyst (CCS) 10 are installed in the necessary locations of the hot air passage 6, and a heater 11 is installed inside the furnace of the evaporation zone 2. . Therefore, the hot air heated in the evaporation zone 2 is circulated and blown not only to the evaporation zone 2 but also to the cure zone 3. On the other hand, in the side part of the cooling zone 4 of the baking furnace 1, there is an air inlet 1 for supplying or discharging cold air.
2. An exhaust port 13 is provided, and cool air is circulated by a blower (not shown).

From a part of the hot air passage 6 of the cure zone 4 arranged as described above, a connecting passage 14 is branched and connected.
is provided, the tip of which connects to the air supply port 15 at the lower end of the preheating furnace.
An exhaust port 16 for discharging the air is provided at the upper end of the preheating furnace. That is, exhaust heat from the cure zone 3 is supplied to the preheating furnace 5. In the preheating furnace 5, preferably, the wire side and the hot air side passages are separated by a partition wall 17 so that impurities such as enamel scum on the hot air side do not have an adverse effect.

A wire rod W is suspended in the upper and lower parts of the baking furnace 1 and the preheating furnace 5 configured as described above, for example, above the lower end and the upper end of the baking path 1, and a roll 1 that is circulated is suspended.
8, 19, 19 are installed.

In order to bake an enamelled electric wire in the baking furnace 1 and preheating furnace 5 configured in this way, first, at the beginning of baking, the wire W sent out from the annealing furnace is guided between the rolls 19 and 19. It is moved from top to bottom inside the preheating furnace 5. During this running, the wire W is preheated by exhaust heat from the curing zone 3 of the baking furnace 1, and its temperature is raised to a predetermined temperature. Thereafter, an enamel coating material is applied by a coating device 20 installed, for example, on the inlet side of the evaporation zone 2 of the baking furnace 1. At the same time as this application, the temperature of the coating material is increased from the inside due to the heat storage of the wire rod W.
Rapid evaporation of the solvent begins. In this state,
Subsequently, the wire W is introduced into the baking furnace 1 and subjected to baking treatment in the same manner as before. At this time, the evaporation zone 2 is heated from the outside by the heating heater 11, but as described above, the inside of the coating material has already been heated due to heat storage due to preheating of the wire W, and evaporation of the solvent has started. Therefore, there is no generation of bubbles due to the evaporation prevention effect of the solvent. That is, the entire thickness of the coating material can be heated quickly and uniformly. Therefore, it is possible to heat up rapidly using a heater with a relatively large amount of heat.
This also allows the linear speed of the wire W to be significantly increased.

Then, from next time onwards, roll 18
It is sufficient to repeat the process by circulating the wire between the rolls 19 and the rolls 19 as many times as necessary, and when baking is completed, winding the wires from the rolls 19 onto an external reel or the like to obtain a completed enameled electric wire.

In the above preheating and baking process, heating of the preheating furnace 5 is performed by exhaust heat from the cure zone 2 of the baking furnace 1, so that energy can be used effectively. Since it is an integral structure with the evaporation zone 2 and cure zone 3 that are kept in the state, there is little heat dissipation and extremely high thermal efficiency is achieved.

Note that exhaust heat to the preheating furnace can be supplied from various sources within the factory, but for example, in the case of a gas-type annealing furnace, exhaust heat can also be obtained from this furnace.

As explained above, according to the present invention, a preheating furnace is provided together with the baking furnace and has a partition wall inside, and the passage on the hot air side of the preheating furnace is provided with exhaust gas from the baking furnace or annealing furnace. Since heat is supplied and the wire is circulated between both furnaces during baking, it is energy efficient and produces high-quality enameled wires that do not produce bubbles in the enamel coating. It is possible to provide a method for baking an enameled electric wire that can be run at high speeds and has extremely high productivity.

[Brief explanation of the drawing]

The figure is a schematic explanatory diagram showing the configuration of a baking furnace and a preheating furnace useful in carrying out the baking method for enamelled electric wire according to the present invention. 1... Baking furnace, 2... Evaporation zone, 3... Cure zone, 4... Cooling zone, 5... Preheating furnace,
W...Wire rod.

Claims (1)

[Claims] 1. A baking method for enameled electric wire in which baking is performed in a baking furnace having an evaporation zone, a cure zone, and a cooling zone, wherein a preheating furnace is provided as an integral structure on one side of the baking furnace, and the preheating furnace A partition wall is provided in the length direction of the interior to separate a passage on the wire side and a passage on the hot air side, and exhaust heat from the baking furnace or annealing furnace is supplied to the passage on the hot air side of the preheating furnace, and the passage on the wire side A method for baking an enameled electric wire, characterized in that the wire can be preheated before application of the enamel coating material by heating the passageway of the wire. 2. A method for baking an enamelled electric wire according to claim 1, characterized in that the running wire is circulated between the baking furnace and the preheating furnace.