JPS5919614B2 - Manufacturing method and device for enamel insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing enamel insulated wires, and particularly to an improvement in an apparatus having a vertical baking furnace.

Enamel insulated wires are usually manufactured by applying enamel to an annealed copper wire or aluminum wire using a vertical enamel baking device and baking the wire.

As shown in FIG. 1, the vertical enamel baking apparatus has a lower opening 3 at the lower end of a baking furnace 1 having a built-in heater 2, an upper opening 10 at the upper end, and an adjustment knob 5 in the lower opening 3.
Air shielding plates 4a and 4b are provided which can be opened and closed by means of an annealing furnace (not shown), and a die 6 held by a die holder 7, a paint tank 8, and a turn sheave 9 are sequentially provided below. The annealed copper wire or soft aluminum wire W (hereinafter referred to as strand wire) is passed through a turn sieve 9 into a paint tank 8 to coat its surface with paint. After adjusting the application amount to
It is baked through the baking furnace 1 through the lower opening 3, cooled through the cooling chamber 11 through the upper opening 10, and turned into a turn sheave 12.
Normally, this operation is repeated 6 to 8 times to produce the product, but in order to be economical, 10 to 30 pieces are produced in parallel and simultaneously in the same baking furnace, with two sizes of one furnace attached on the left and right. It is common to In this manufacturing process, the enamel paint applied to the strands W is heated by the heater 2, evaporating the solvent, and when the paint film is cured, solvent gas is generated. is provided with a combustion chamber 13, a catalyst 15 is provided in the combustion chamber 13, the gas is reacted and combusted by the catalyst 15, a part of which is discharged into the atmosphere by a blower 16, and a part of which is inside the furnace 1. The structure is such that it is circulated and reused for heating for baking.

In addition, since the baking furnace 1 generates an upward air current due to the chimney effect due to the vertical furnace, a gap 17 is provided at the outlet of the upper opening 10, and a structure is used to prevent this by blowing fresh air at high speed from the outside into the gap 17. An air curtain device is provided. Note that 18 is an exhaust passage of the air curtain device.

The effective length of the vertical enamel baking furnace 1 varies depending on the type of furnace, but the standard is usually 5 to 8 m, and the baking temperature varies depending on the type of enamel paint and baking conditions. However, the upper part of the furnace is 400-500℃, the middle part of the furnace is 3
It is normal to set the temperature in the range of 50 to 450°C and 200 to 350°C in the lower part of the furnace. The above is a description of the structure of a typical conventional baking device, and other devices have been considered in which various improvements have been made to the solvent gas combustion system and the catalyst.

However, as mentioned above, the conventional vertical enamel printing apparatus has
It has the following drawbacks: First, for example, 2.511φJ
When manufacturing thick enamel insulated wires such as ISL type formal copper wire, the flammable organic solvent content of formal paint is as high as 76-82%, 2.511! 8m/φ line
When produced at a baking rate of 15 minutes, the heat of formation of the combustible organic solvent at the catalyst 15 is 1500 to 1800 minutes, and the catalyst 15
The temperature of the hot air after passing through varies depending on the circulation flow rate, but
The temperature rises to ~800°C.

However, the maximum heat-resistant temperature of the catalyst 15 is said to be below 600°C, and if the catalyst 15 is operated for a long time at such high temperatures, the catalyst 15 will
has a very short lifespan. For this reason, excess air is introduced into the furnace from outside the furnace 1 to adjust the catalyst outlet temperature to 600° C. or less.

This air intake has been provided at the lower opening 3 of the furnace 1, or in some cases at the front 14 of the catalyst 15. However, if air is taken in from the lower opening 3 of the furnace 1, an air shielding plate 4a as shown in FIG.
, 4b is such that the running wire W
, 4b, the distance between them is 15 ~
2011, and an excessive amount of air is sucked in due to the chimney effect of the vertical furnace and the circulating airflow in the furnace, and this excess air is inevitably heated to the set temperature in the furnace 1, so However, the catalyst 15
If air is taken in at the front 14 of the air intake port 14,
Since it is close to the catalyst, it is difficult to mix the cold air and hot air uniformly, and in some cases, there is a risk that solvent gas may pass through unburned. Furthermore, as shown in Fig. 1, the conventional furnace has a structure in which a part of the combustion gas is circulated from the upper part of the furnace 1 and reused for baking heating, and this is done in the opposite direction to the running direction of the strand W. However, if the air is circulated against the flow of air in the furnace 1, the hot air circulation path in the running part of the wire w If it is long, there will be a local reversal of the hot air in the width direction of the furnace, creating the risk of the area being filled with solvent gas and causing an explosion. The drawback was that it could not be made longer.

In view of the above, it is an object of the present invention to provide an apparatus for manufacturing an enameled insulated wire that solves the above-mentioned drawbacks. In an apparatus for manufacturing an enameled insulated wire, the die and the paint tank are arranged below, and an air curtain device is provided near the upper opening.

A sealed chamber is provided at the bottom opening of the baking furnace, and the high temperature gas generated by burning solvent vapor in the furnace is mixed with fresh air from outside and after catalytic combustion, a part of it is passed through the bottom of the furnace. It is characterized in that it is circulated into the furnace from one or more appropriate locations within λ of the effective furnace length of the baking furnace. Hereinafter, an embodiment of the present invention will be described with reference to FIG. 2. Reference numeral 20 denotes a vertical baking furnace having a built-in heater 21, a lower opening 22 at the lower end, and an upper opening 23 at the upper end.
The lower opening 22 is sealed with a sealed chamber 24 that can be opened and closed, for example, by a hinge 25.

The reason why this sealed chamber 24 is constructed to be openable and closable is to enable line hanging work. The sealed chamber 24 is provided with a passage hole 26 at its lower end through which the wire W passes, and a removable die holder 28 is provided adjacent to this passage hole 26, a die 27 is attached to this, and an enamel plate is attached below the passage hole 26. A paint tank 29 is provided.

This paint tank 29 can also be provided integrally with the die holder 28. Reference numeral 30 denotes a combustion chamber equipped with a catalyst 31, one end of which is communicated with the tip of the baking furnace 20, and the other end communicated with one end of a ventilation passage 32.

Further, the other end of the ventilation passage 32 communicates with the lower part of the baking furnace 20.

The communication position of this ventilation passage 32 with the baking furnace 20 is
Appropriate 1 or 2 within 1 of the effective furnace length from the bottom of 0
These are the hot air (high temperature gas) inside the furnace 20.
The hot air (high-temperature gas) is circulated in the vertical rising direction that cannot go against the natural ventilation direction, that is, in the forward direction of the running direction of the wire W, and the hot air (high-temperature gas) circulation path in the running part of the wire W is maximized. Even if the length is long, there will be localized hot air (high temperature gas) in the width direction of the furnace.
This is to prevent the occurrence of a reversal phenomenon and to prevent problems such as poor appearance and foaming due to enamel baking. 33
is an air curtain device installed in the upper part of the baking furnace 20,
This air curtain device 33 is communicated with an intake port 34 for fresh air from the outside.

35 is a blower (equipped with a variable speed motor) built into the combustion chamber 30, which sucks the air blown into the air curtain device 33 and the solvent vapor generated in the furnace 20 into the combustion chamber 30; High temperature gas after catalytic combustion within the combustion chamber 30 is circulated into the baking furnace 20 via the ventilation path 32.

Furthermore, it is preferable that a damper 36, a flow meter (not shown), etc. be provided in the ventilation path 32, and the amount of high-temperature gas flowing into the furnace 20 can be adjusted by the blower 35.

In addition, 37 is a discharge path for excess high temperature gas, 39 is a cooling chamber, and 4
0,41 is a turn sheave.

The enamel insulated wire is manufactured by applying paint to the surface of the wire W through the paint tank 29 via the turn sheave 40, and then adjusting the paint to a uniform thickness layer with the die 27, and then passing it through the passage hole 26. The material is passed through the closed chamber 24 and then into the baking furnace 20 through the lower opening 22 to be baked, passed through the cooling chamber 39 to be cooled and solidified, and then pulled out through the turn sheave 41 for manufacturing.

Therefore, in the present invention, the lower opening 22 of the baking furnace 20 is sealed with a sealed chamber 24 to block outside air, and the baking furnace 20 has a
Fresh air and high-temperature gas (hot air) from the upper air curtain device 33' are sucked into the combustion chamber 30 by the blower 35 and mixed uniformly, while the high-temperature gas (hot air) is catalytically combusted by the catalyst 31.
Only hot air) will be circulated through the air passage 32,
Further, since the communication position of the ventilation passage 32 with the baking furnace 20 is within one part of the effective furnace length from the lower part of the furnace, the circulation of the high temperature gas is carried out in the natural ventilation direction of the high temperature gas and in the running direction of the strands W. The direction is forward, and the circulation path for high-temperature gas is maximized.

Therefore, there is little loss of energy, there is no local reversal of high temperature gas in the width direction of the furnace, and there is no blow-up phenomenon from the furnace that is observed in conventional furnaces.

In addition, by forcibly discharging an appropriate amount of high-temperature gas from the discharge passage 37 using the blower 35,
Since more fresh air can be introduced and the temperature in the vicinity of the catalyst 31 can be adjusted appropriately, the temperature in the vicinity of the catalyst 31 and the combustion chamber 30 can be adjusted appropriately.
The discharge temperature does not reach a high temperature of 600 to 800°C, and the high temperature gas circulating in the furnace 20 can be blown at an appropriate temperature.

Furthermore, since the circulating high-temperature gas (hot air) also passes through the ventilation path 32, it does not come into contact with the heater 21 of the furnace 20, so there is no wasted power consumption. Also, although the number of communication ports between the ventilation passage 32 and the furnace 20 is not limited, if there are two communication ports as in the embodiment shown in the drawings, when the temperature is adjusted according to the set temperature of the furnace, the amount of inflow of high-temperature gas will be reduced. It is preferable because the temperature can be easily controlled.

In addition, if the communication position between the ventilation passage 32 and the furnace 20 is too low, there is a risk of foaming and poor appearance when baking the enamel depending on the type of enamel paint. It has been confirmed that there is no problem if the lowermost part is set as an evaporation zone and a conventional electric heater is installed as appropriate for heating.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example, and FIG. 2 is a sectional view showing an embodiment of the present invention. 20... Baking furnace, 21... Heater,
22... Lower opening, 24... Sealed chamber,
30... Combustion chamber, 31... Catalyst, 32
...Vent passage, 33...Air curtain device, 35...Blower 1, 37...Discharge channel.

Claims (1)

[Claims] 1. The wire is passed through a paint tank to apply enamel paint on the conductor, then passed through a die to homogenize the enamel paint layer on the conductor to a predetermined thickness, and then heated to a high temperature. In a method for producing an enamel insulated wire, the method includes passing the solvent through a baking furnace to volatilize and remove the solvent of the enamel paint layer to bake the enamel paint layer onto the wire, and then cooling the wire through a cooler. is extracted from the vicinity of the upper opening of the firing furnace to the outside of the firing furnace, mixed with air and combusted to produce high-temperature gas, and a part or all of this high-temperature gas is transferred from the vicinity of the lower opening of the firing furnace to the outside of the firing furnace. A method for manufacturing an enameled insulated wire, which comprises: blowing into the furnace and discharging the remainder to the outside of the system, and circulating what has been blown into the furnace in a flow manner in the furnace in the same direction as the running direction of the strands. 2. In an enamelled insulated wire manufacturing apparatus comprising a vertical baking furnace having a lower opening at the lower end and an upper opening at the upper end, a die and a paint tank are arranged below, and an air curtain device is provided above, the lower part of the baking furnace is A closed chamber is provided in the opening, and a blowing port is provided for extracting the solvent gas generated in the furnace to the outside of the furnace, mixing it with air and blowing the obtained high-temperature gas into the furnace as a heated gas. 1. An apparatus for manufacturing an enameled insulated wire, characterized in that one or more wires are provided at an appropriate location adjacent to the lower opening and within a range of 2/7 of the effective furnace length of the baking furnace from the lower opening. 3. The enamel insulated wire manufacturing apparatus according to claim 2, characterized in that a damper is provided in part or all of the blowing port.