JP2021012855A - Manufacturing device of insulated wire and manufacturing method of insulated wire - Google Patents

Abstract

To provide a manufacturing device of an insulated wire difficult to cause varnish to foam at manufacturing, with improved manufacturing capacity, while suppressing a size increase of manufacturing facilities and a rise in production costs.SOLUTION: A manufacturing device of an insulated wire includes: a coating and drying part configured to coat and dry varnish while making a linear conductor travel in an axial direction thereof; and a curing part arranged at a downstream side in a travel direction of the conductor of the coating and drying part and configured to cure the varnish. The coating and drying part includes: a coating device configured to coat the conductor with the varnish; and a heating furnace configured to heat the conductor after coating with the varnish. The curing part includes an induction heating tool configured to heat the conductor.SELECTED DRAWING: Figure 2

Description

The present invention relates to an insulated wire manufacturing apparatus and a method for manufacturing an insulated wire.

Insulated electric wires in which a linear conductor is coated with an insulating paint (varnish) are known. This insulated wire is manufactured by repeatedly applying and baking a varnish on the outer peripheral surface of the conductor until the insulating coating reaches a predetermined thickness while running the linear conductor in the axial direction.

As an apparatus for manufacturing such an insulated wire, a coating portion for applying varnish to the surface of a running conductor and a heating portion for forming an insulating layer on the conductor surface by heating the conductor coated with varnish are provided. A manufacturing apparatus provided is known (see JP-A-2015-43305).

In the above-mentioned insulated wire manufacturing apparatus, the coated varnish is dried and hardened by heating the conductor, so that an insulating layer is formed on the conductor surface. At this time, if the conductor is suddenly heated, the applied varnish tends to foam, and the insulating property of the formed insulating layer may deteriorate. For this reason, it is common to use a hot air circulation type heating furnace that is heated relatively slowly by convection and radiation.

JP-A-2015-43305

In an insulated wire manufacturing device using a hot air circulation heating furnace, it is necessary to increase the traveling speed of the conductor in order to improve the manufacturing capacity of the insulated wire. If only the traveling speed is increased, the time for the conductor to pass through the hot air circulation type heating furnace is shortened, so that the time for the varnish to sufficiently dry and harden is insufficient. In order to make up for this shortage of time, there are a method of extending the length of the hot air circulation type heating furnace and a method of raising the furnace temperature.

In the former case, it is necessary to extend the length of the hot air circulation type heating furnace as the traveling speed increases. In the insulated wire manufacturing equipment, the hot air circulation type heating furnace occupies a large proportion of the manufacturing equipment, so that the insulated wire manufacturing equipment becomes large and it becomes difficult to secure space for the equipment.

In the latter method of raising the furnace temperature, there is a limit to the furnace temperature that can be raised from the viewpoint of heat resistance of the equipment, and the running cost increases more than the increase in the furnace temperature, so that the manufacturing cost may increase.

The present invention has been made based on the above circumstances, and is an insulated wire in which foaming of varnish is unlikely to occur during manufacturing, and the manufacturing capacity is improved while suppressing the increase in size of manufacturing equipment and the increase in manufacturing cost. It is an object of the present invention to provide a manufacturing apparatus and a manufacturing method of an insulated electric wire.

The apparatus for manufacturing an insulated electric wire according to one aspect of the present invention includes a coating and drying portion for applying and drying varnish while traveling a linear conductor in the axial direction thereof, and a downstream side of the coating and drying portion in the traveling direction of the conductor. The coating and drying unit has a coating device for applying the varnish to the conductor and a heating furnace for heating the conductor after the varnish is applied, and is provided with a curing portion for curing the varnish. The cured portion has an induction heater that heats the conductor.

The insulated wire manufacturing apparatus and the insulated wire manufacturing method of the present invention can improve the manufacturing capacity while suppressing foaming of the varnish during manufacturing and suppressing an increase in the size of the manufacturing equipment and a manufacturing cost.

FIG. 1 is a schematic configuration diagram of an insulated wire manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view showing the configurations of the coated and dried portion and the cured portion of the insulated wire manufacturing apparatus of FIG. FIG. 3 is a schematic view showing a detailed configuration of the coating device of FIG. FIG. 4 is a schematic view showing a detailed configuration of the cured portion of FIG. FIG. 5 is a flow chart showing a method of manufacturing an insulated wire according to an embodiment of the present invention.

[Explanation of Embodiments of the Present Invention]
The apparatus for manufacturing an insulated electric wire according to one aspect of the present invention includes a coating and drying portion for applying and drying varnish while traveling a linear conductor in the axial direction thereof, and a downstream side of the coating and drying portion in the traveling direction of the conductor. The coating and drying unit has a coating device for applying the varnish to the conductor and a heating furnace for heating the conductor after the varnish is applied, and is provided with a curing portion for curing the varnish. The cured portion has an induction heater that heats the conductor.

In the insulated wire manufacturing apparatus, the varnish is less likely to foam because it is slowly dried in a heating furnace having a long furnace length after the varnish is applied to the conductor in the coating and drying section. Further, since the equipment cost per unit length of the heating furnace is small, it is possible to suppress an increase in the manufacturing cost even if the furnace length is long. On the other hand, in the insulated wire manufacturing apparatus, the dried varnish is cured by an induction heater at the cured portion. Since the induction heater can easily raise the temperature of the conductor in substantially proportional to the input electric power, the varnish can be cured with a shorter furnace length than the heating furnace. Therefore, even if the traveling speed of the conductor is increased to improve the manufacturing capacity, it is possible to suppress an increase in the size of the manufacturing equipment and an increase in the manufacturing cost. Furthermore, with dried varnish, foaming of the varnish is unlikely to occur even if rapid heating is performed. Therefore, the insulated wire manufacturing apparatus can improve the manufacturing capacity while suppressing the foaming of the varnish and suppressing the increase in the size of the manufacturing equipment and the manufacturing cost.

It is preferable that the induction heater has a plurality of heating regions in which the heating temperature of the conductor can be independently controlled along the traveling direction of the conductor. As described above, by making the induction heater have a plurality of heating regions in which the heating temperature of the conductor can be independently controlled along the traveling direction of the conductor, the temperature control of the conductor can be easily performed. Therefore, the conductor can be quickly heated to a desired temperature and then maintained at that temperature. Such temperature control can further improve the manufacturing capacity.

It is preferable that the conductor is configured to repeatedly pass through the coating and drying portion and the curing portion in this order. If an amount of varnish corresponding to the thickness of the insulating layer required for the conductor is applied at one time, it takes time to dry the varnish and it becomes easy to foam. By forming the insulating layer on the conductor while repeating coating, drying and curing in this way, it is possible to efficiently form the insulating layer while suppressing the foaming of the varnish.

It is preferable that the conductor is configured to repeatedly pass through the coating device and the heating furnace in this order in the coating and drying section. In this way, by repeating coating and drying on the conductor a certain number of times in the coating and drying portion and then curing in the cured portion, the equipment required for curing can be reduced. Therefore, the equipment cost and the installation space can be reduced, and the running cost can be reduced.

The method for manufacturing an insulated wire according to another aspect of the present invention includes a step of applying varnish while running a linear conductor in the axial direction thereof, and a step of drying the varnish applied to the conductor in a heating furnace. The varnish after the drying step is hardened by an induction heater.

In the method for manufacturing the insulated wire, the varnish is less likely to foam because the varnish is applied to the conductor and then slowly dried in a heating furnace having a long furnace length. Further, since the equipment cost per unit length of the heating furnace is small, it is possible to suppress an increase in the manufacturing cost even if the furnace length is long. On the other hand, in the method of manufacturing the insulated wire, the dried varnish is cured by an induction heater. Since the induction heater can easily raise the temperature of the conductor in substantially proportional to the input electric power, the varnish can be cured with a shorter furnace length than the heating furnace. Therefore, even if the traveling speed of the conductor is increased to improve the manufacturing capacity, it is possible to suppress an increase in the size of the manufacturing equipment and an increase in the manufacturing cost. Furthermore, with dried varnish, foaming of the varnish is unlikely to occur even if rapid heating is performed. Therefore, by using the method for manufacturing the insulated wire, it is possible to improve the manufacturing capacity while suppressing the foaming of the varnish and suppressing the increase in the size of the manufacturing equipment and the manufacturing cost.

In addition, in this specification, a "heating furnace" refers to a furnace which heats by transferring the heat generated by electric heat or combustion to an object to be heated.

[Details of Embodiments of the present invention]
Hereinafter, embodiments of the insulated wire manufacturing apparatus and the insulated wire manufacturing method according to the present invention will be described in detail with reference to the drawings.

[Insulated wire manufacturing equipment]
The insulated wire manufacturing apparatus shown in FIG. 1 includes a pair of drums 1 (first drum 1a and second drum 1b) and a conductor W, which are arranged in parallel and run on a conductor W on a line spanning one or a plurality of turns. The coated and dried portion 2 that applies and dries the varnish while traveling in the axial direction thereof, and the cured portion 3 that is installed on the downstream side of the conductor W of the coated and dried portion 2 in the traveling direction and cures the varnish. It includes a delivery unit 4 that sends the conductor W to the first drum 1a, and a conductor W on which an insulating layer is formed, that is, a winding unit 5 that winds the insulated wire.

<Conductor>
The material and composition of the conductor W are not particularly limited, but for example, copper wire, tin-plated copper wire, aluminum wire, aluminum alloy wire, steel core aluminum wire, copper fly wire, nickel-plated copper wire, and silver plating. A copper wire, a copper-covered aluminum wire, or the like can be used. Further, the cross-sectional shape of the conductor W is not particularly limited, and may be a polygonal shape such as a circular shape (round line), an elliptical shape, or a square shape (flat line).

<Sending part>
The delivery unit 4 sends the conductor W wound around the reel to the first drum 1a. The reel of the delivery unit 4 may be a driven type or a non-driven type. When the reel of the delivery unit 4 is a drive type, it is preferable to control the drive of the transmission unit 4 so that excessive slack or tension does not occur in the conductor W between the first drum 1a. A known motor such as a servo motor or a stepping motor can be used to drive the delivery unit 4.

<Drum>
The first drum 1a and the second drum 1b are arranged so as to face each other in the vertical direction with the coating drying portion 2 and the curing portion 3 interposed therebetween, and the first drum 1a is arranged on the lower side and the second drum 1a is arranged on the upper side. The drum 1b is arranged. The first drum 1a and the second drum 1b orbit the conductor W. The first drum 1a and the second drum 1b are extended in a direction perpendicular to the paper surface of FIG. 1, and the position where the conductor W is hung is shifted in the axial direction of the drum 1 toward the back side of the paper surface at regular intervals. It is possible to orbit the conductor W with. The conductor W on which the insulating layer is formed by circulating between the drums 1 a certain number of times, that is, the insulated electric wire, is finally wound around the winding portion 5 provided on the downstream side in the traveling direction of the conductor W. As the material of the drum 1, metal, resin, or the like can be used. The first drum 1a is a drive drum, and is rotationally driven by a drive unit (not shown). The second drum 1b is rotatably supported and rotates as the conductor W travels.

<Applying and drying part>
As shown in FIG. 2, the coating / drying unit 2 includes a coating device 21 for coating the conductor W with varnish, and a heating furnace 22 for heating the conductor W after coating the varnish.

As described above, the conductor W orbits between the drums 1 a certain number of times, and passes through the coating device 21 and the heating furnace 22 in this order each time. Further, in the coating / drying section 2 shown in FIG. 2, the conductor W is manufactured so as to pass through the curing section 3 after passing through the coating device 21 and the heating furnace 22 in the coating / drying section 2 three times in a row. The device is configured. That is, in the insulated wire manufacturing apparatus, the conductor W is configured to repeatedly pass through the coating apparatus 21 and the heating furnace 22 three times in this order at the coating drying section 2. In this way, the time required for curing can be shortened by repeatedly applying and drying to the conductor W in the coating / drying unit 2 and then curing in the curing unit 3. As a result, the manufacturing capacity of the insulated wire can be improved while suppressing the insulating property of the insulating layer.

In FIG. 2, the coating drying section 2 is configured so that the conductor W passes through a different coating device 21 for each circuit. For example, when the same type and the same concentration of varnish is applied, the conductor W rotates. It is also possible to have a configuration in which one coating device 21 is passed through each time. Further, the conductor W may be provided with a plurality of coating devices 21 having a number of times less than the number of circumferences of the conductor W, and the conductor W may pass once or a plurality of times to one coating device 21.

On the contrary, in FIG. 2, the coating and drying unit 2 is configured so that the conductor W passes through the same heating furnace 22 for each orbit. For example, when the temperature is controlled for each orbit, the conductor W orbits. It may be configured to pass through a different heating furnace 22 for each. Further, a plurality of heating furnaces 22 having a number of times less than the number of circumferences of the conductor W may be provided, and the conductor W may pass once or a plurality of times to one heating furnace 22.

(Applying device)
As shown in FIG. 3, the coating device 21 is provided on the downstream side of the varnish tank 21a for storing the varnish and the conductor W of the varnish tank 21a in the traveling direction, and the coating die W through which the conductor W passing through the varnish tank 21a is inserted is inserted. 21b and the like. The coating device 21 applies varnish to the outer peripheral surface of the conductor W that orbits the first drum 1a and the second drum 1b.

A through hole through which the conductor W penetrates is provided at the bottom of the varnish tank 21a, and the varnish of the varnish tank 21a is applied to the outer peripheral surface of the conductor W penetrating the through hole. When the number of times the conductor W has passed through one coating device 21 is plurality, the through holes are arranged as many times as the number of times of passing at a desired interval so that the conductor W can easily orbit.

The varnish applied to the outer peripheral surface of the conductor W is adjusted to have a substantially uniform thickness according to the diameter of the die hole by inserting the conductor W into the coating die 21b. The coating die 21b is provided for each coating device 21 for each orbit of the conductor W regardless of the number of times the conductor W has passed. That is, the same number of coating dies 21b as the number of times the conductor W has passed is provided. The diameter of the die hole of the coating die 21b is increased as much as the coating die 21b located on the downstream side in the traveling direction of the conductor W. By gradually increasing the diameter of the coating die 21b in this way, the coating formed on the outer peripheral surface of the conductor W can be gradually thickened, and an insulating layer having a constant thickness can be formed.

Therefore, the number of the coating dies 21b is determined from the thickness of the insulating layer formed at one time and the total thickness of the required insulating layer. The number of orbits of the conductor W can be the same as the number of the coating dies 21b.

As the varnish, a resin in which a resin constituting an insulating layer is dissolved in a solvent is used. The constituent resin is not particularly limited as long as it has high insulating properties and high heat resistance. Specific examples thereof include polyimide, polyamide-imide, and polyesterimide. Further, as the solvent, for example, pyrrolidone, cresol and the like can be used.

(heating furnace)
The heating furnace 22 heats the conductor W after applying the varnish to evaporate the solvent and dry the varnish.

The heating furnace 22 is not particularly limited, but a furnace that heats the conductor W by convection and radiation using heat generated by electric heat or combustion as an energy source can be used. A heater can be used as the electric heating. Further, the above-mentioned combustion includes a combustion that takes in a solvent that evaporates from the varnish together with the fuel and burns it. Since the heating furnace 22 heats the conductor W relatively gently by convection and radiation, foaming of the varnish is unlikely to occur during heating.

As the heating furnace 22, a hot air circulation type heating furnace that heats the conductor W with hot air circulating is preferable. By heating the conductor W with hot air, the temperature distribution on the outer peripheral surface of the conductor W can be easily made uniform, so that the manufactured insulated electric wire can be made uniform.

The heating temperature of the conductor W passing through the heating furnace 22 (atmospheric temperature in the heating furnace 22) is a temperature at which the solvent can be evaporated from the varnish. Specifically, the lower limit of the atmospheric temperature in the heating furnace 22 is preferably 150 ° C., more preferably 200 ° C. On the other hand, the upper limit of the atmospheric temperature is preferably 600 ° C., more preferably 500 ° C. If the ambient temperature is less than the above lower limit, the solvent may not evaporate sufficiently, or the furnace length of the heating furnace 22 may become unnecessarily large. On the contrary, if the ambient temperature exceeds the upper limit, the heat resistance of the heating furnace 22 may be insufficient or the conductor W may be thermally damaged.

The furnace length of the heating furnace 22 is set to a length at which the solvent sufficiently evaporates from the varnish, and is appropriately determined depending on the traveling speed of the conductor W and the atmospheric temperature in the heating furnace 22.

As described above, in the heating furnace 22, since the conductor W is heated gently, foaming of the varnish is unlikely to occur during heating. Since the conductor W is heated slowly, the furnace length required for heating is inevitably long. Since the equipment cost per unit length of the heating furnace 22 is smaller than that of the induction heater 31, which will be described later, for example, an increase in equipment cost can be suppressed even with such a long furnace length. Therefore, the insulated wire manufacturing apparatus can suppress an increase in manufacturing cost by providing the heating furnace 22.

<Hardened part>
As shown in FIG. 2, the cured portion 3 has an induction heater 31 that heats the conductor W. The cured portion 3 cures the resin contained in the varnish after the solvent has evaporated in the coating and drying portion 2, and forms an insulating coating on the outer periphery of the conductor W.

In the curing portion 3 shown in FIG. 2, the insulating wire manufacturing apparatus is configured such that the conductor W passes through the curing portion 3 after passing through the coating device 21 and the heating furnace 22 in the coating drying section 2 three times in a row. Has been done. The insulated wire manufacturing apparatus is configured such that the conductor W that has passed through the cured portion 3 passes through the coated and dried portion 2 again and passes through the cured portion 3. That is, the insulated wire manufacturing apparatus is configured such that the conductor W repeatedly passes through the coating and drying portion 2 and the cured portion 3 in this order. By forming an insulating layer on the conductor W while repeating coating, drying and curing in this way, the equipment required for curing can be reduced. Therefore, the equipment cost and the installation space can be reduced, and the running cost can be reduced.

The induction heater 31 directly heats the conductor W by using an electromagnetic induction current generated in the conductor W due to a change in the magnetic field (alternating magnetic field). The frequency of the induction heater 31 (frequency of the current for generating the alternating magnetic field) is appropriately determined from the viewpoint of heating efficiency and equipment cost, and can be, for example, 10 kHz or more and 10 MHz or less.

In induction heating, since a magnetic field is generated, the magnetic field is strengthened in proportion to the magnitude of the current flowing through the coil, and the current induced in the conductor W is also increased in proportion to the strength of the magnetic field. Since the calorific value of the conductor W is proportional to the square of the induced current, the induction heater 31 can heat the conductor W in proportion to the square of the current flowing through the coil for generating a magnetic field. Therefore, by increasing the current so as to generate heat in proportion to the required traveling speed, the conductor W does not extend the distance through which the conductor W passes through the inside of the induction heater 31 (the heating distance of the induction heater 31). The required heating is possible. Therefore, the heating distance can be, for example, 1/10 or more and 1/2 or less with respect to the length of the heating furnace. Further, since it is directly heated, it is unlikely that the heating temperature is restricted due to the heat resistance of the equipment.

As shown in FIG. 4, the induction heater 31 conducts three heating regions (first heating region 31a, second heating region 31b, and third heating region 31c) in which the heating temperature of the conductor W can be controlled independently. It is held along the traveling direction of W. The conductor W inserted into the induction heater 31 is quickly heated to a desired temperature (a temperature suitable for curing the resin contained in the varnish) and passes through the induction heater 31 while keeping the temperature constant. It is preferable to do so. Specifically, for example, a large induced current is generated in the conductor W in the first heating region 31a to perform rapid heating, and the heating amount is adjusted so that the temperature of the conductor W approaches a desired temperature in the second heating region 31b. It is preferable to control so that the temperature of the conductor W is kept constant in the third heating region 31c. In this case, since the magnitude of the current to be induced in the conductor W is different in each region, the heating temperature of the conductor W can be independently controlled by the first heating region 31a, the second heating region 31b, and the third heating region 31c. There must be. That is, by making the induction heater 31 have a plurality of heating regions in which the heating temperature of the conductor W can be independently controlled along the traveling direction of the conductor W, the temperature of the conductor W can be easily controlled. Therefore, the conductor W can be quickly heated to a desired temperature and then maintained at that temperature. Such temperature control can further improve the manufacturing capacity. The desired temperature is a temperature at which the resin contained in the varnish can be cured, and is, for example, 150 ° C. or higher and 600 ° C. or lower.

The first heating region 31a, the second heating region 31b, and the third heating region 31c may be configured by dividing the inside of one induction heater 31 into three regions, but three independent induction heaters are arranged side by side. It can also be configured.

Further, the heating distances of the first heating region 31a, the second heating region 31b and the third heating region 31c are appropriately determined by the required temperature control. Therefore, the heating distances of the first heating region 31a, the second heating region 31b, and the third heating region 31c may be the same, but may be different.

There may be voids between the first heating region 31a and the second heating region 31b, and between the second heating region 31b and the third heating region 31c.

In FIG. 4, the induction heater 31 has three heating regions, but the number of regions in the heating region is not limited to three, and may be two or four or more. Further, the induction heater 31 may not have a plurality of heating regions in which the heating temperature of the conductor W can be controlled independently, that is, it may be capable of controlling only one temperature as a whole.

The heating distance of the induction heater 31 (the total heating distance of each of the first heating region 31a, the second heating region 31b, and the third heating region 31c) is set to a length that can sufficiently cure the resin contained in the varnish, and the induction heating is performed. It is appropriately determined depending on the temperature profile of the conductor W heated by the vessel 31 and the traveling speed of the conductor W. Since it is difficult to contribute to the heating of the conductor W near the inlet and outlet of the induction heater 31, the length of the heating region of each induction heater 31 is preferably 100 mm or more from the viewpoint of heating efficiency.

Specifically, the ratio of the furnace length of the heating furnace 22 to the heating distance of the induction heater 31 can be 6: 1 or more and 10: 1 or less. As described above, in the insulated wire manufacturing apparatus, the heating distance of the induction heater 31 can be shortened as compared with the furnace length of the heating furnace 22. Therefore, the furnace length of the heating furnace 22 can be made longer than that in the case where only the heating furnace is used for the same insulated wire manufacturing equipment space. Therefore, even if the traveling speed of the conductor W is increased, the varnish applied to the conductor W can be reliably dried and cured.

<Winding section>
The take-up unit 5 pulls the conductor W and winds it on a reel. Due to the tensile force of the winding portion 5, the conductor W orbits between the coating drying portion 2 and the curing portion 3. A known motor such as a servo motor or a stepping motor can be used to drive the take-up unit 5.

[Manufacturing method of insulated wire]
Next, a method of manufacturing the insulated wire will be described. As shown in FIG. 5, the method for manufacturing the insulated wire includes a coating step S1, a drying step S2, and a curing step S3. The method for manufacturing the insulated wire can be performed using the insulated wire manufacturing apparatus shown in FIG.

<Applying process>
In the coating step S1, the varnish is applied while the linear conductor W runs in the axial direction thereof. Specifically, the conductor W is sent out from the delivery unit 4, passed through the first drum 1a, and travels on the coating device 21.

The conductor W is inserted through a through hole at the bottom of the varnish tank 21a, and the insulating varnish is applied to the outer peripheral surface by passing through the varnish stored in the varnish tank 21a. Then, the varnish applied to the outer peripheral surface of the conductor W is adjusted to have a substantially uniform thickness according to the diameter of the die hole by inserting the conductor W into the coating die 21b.

<Drying process>
In the drying step S2, the varnish applied to the conductor W is dried in the heating furnace 22. Specifically, the conductor W that has passed through the coating die 21b is driven through the heating furnace 22.

As a result, when the varnish applied to the conductor W passes through the heating furnace 22, the solvent evaporates and the varnish dries.

The coating step S1 and the drying step S2 may be repeated a plurality of times in this order before the curing step S3 is performed.

<Curing process>
In the curing step S3, the varnish after the drying step S2 is cured by the induction heater 31. Specifically, the induction heater 31 is driven by the conductor W that has passed through the heating furnace 22.

As a result, the resin contained in the varnish after the solvent evaporates in the drying step S2 is cured, and an insulating coating is formed on the outer periphery of the conductor W.

The coating step S1, the drying step S2, and the curing step S3 may be repeated in this order.

Through the above steps, an insulating layer is formed on the outer periphery of the conductor W, and an insulated electric wire can be manufactured.

〔advantage〕
In the insulated wire manufacturing apparatus and the insulated wire manufacturing method, the varnish is less likely to foam because it is slowly dried in the heating furnace 22 having a long furnace length after the varnish is applied to the conductor W. Further, since the equipment cost per unit length of the heating furnace 22 is small, it is possible to suppress an increase in the manufacturing cost even if the furnace length is long. In the insulated wire manufacturing apparatus and the insulated wire manufacturing method, the dried varnish is cured by the induction heater 31. Since the induction heater 31 can easily raise the temperature of the conductor W substantially in proportion to the input electric power, the varnish can be cured with a shorter furnace length than the heating furnace. Therefore, even if the traveling speed of the conductor W is increased to improve the manufacturing capacity, it is possible to suppress an increase in the size of the manufacturing equipment and an increase in the manufacturing cost. Furthermore, with dried varnish, foaming of the varnish is unlikely to occur even if rapid heating is performed. Therefore, by using the insulated wire manufacturing apparatus and the insulated wire manufacturing method, it is possible to improve the manufacturing capacity while suppressing the foaming of the varnish and suppressing the increase in the size of the manufacturing equipment and the manufacturing cost.

[Other Embodiments]
It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is not limited to the configuration of the above embodiment, but is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. To.

In the above embodiment, the case where the conductor passes through the coating device and the heating furnace three times in this order in the coating drying portion has been described, but the number of repetitions is not limited to three times, but may be two times or four times or more. May be good. The number of repetitions is preferably 2 or more and 5 or less from the viewpoint of the effect of shortening the curing time and the suppression of deterioration of the insulating property of the insulating layer.

Further, in the above embodiment, the number of repetitions is fixed at 3 times, and the number of repetitions is the same when the conductor passes through the cured portion and goes around, and then the conductor passes through the coating and drying portion. May be different each time it passes through the hardened portion and goes around.

Further, it is also an object of the present invention that the number of repetitions is one, that is, the conductor does not repeatedly pass through the coating device and the heating furnace in the coating drying portion, but passes through the curing portion each time it passes through the coating device and the heating furnace. I'm about to do it.

In the above embodiment, the case where the conductor repeatedly passes through the coating drying portion and the cured portion in this order has been described, but the configuration in which the coating drying portion and the cured portion are not repeated in this order, that is, the cured portion is 1 on the downstream side of the coating drying portion It is also an object of the present invention to provide only one configuration.

As described above, the insulated wire manufacturing apparatus and the insulated wire manufacturing method of the present invention are less likely to cause foaming of varnish during manufacturing, and can improve the manufacturing capacity while suppressing an increase in the size of the manufacturing equipment and a manufacturing cost. ..

1 Drum 1a 1st drum 1b 2nd drum 2 Coating drying section 21 Coating device 21a Varnish tank 21b Coating die 22 Heating furnace 3 Curing section 31 Induction heater 31a 1st heating region 31b 2nd heating region 31c 3rd heating region 4 Sending Part 5 Winding part W conductor

Claims (5)

A coating and drying section that applies and dries varnish while running a linear conductor in the axial direction.
It is provided on the downstream side of the coating and drying portion in the traveling direction of the conductor and has a curing portion for curing the varnish.
The coating / drying unit has a coating device for applying the varnish to the conductor and a heating furnace for heating the conductor after the varnish is applied.
An insulated wire manufacturing apparatus in which the cured portion has an induction heater for heating the conductor. The apparatus for manufacturing an insulated electric wire according to claim 1, wherein the induction heater has a plurality of heating regions in which the heating temperature of the conductor can be independently controlled along the traveling direction of the conductor. The insulated wire manufacturing apparatus according to claim 1 or 2, wherein the conductor is configured to repeatedly pass through the coated and dried portion and the cured portion in this order. The insulated wire manufacturing apparatus according to claim 1, claim 2 or claim 3, wherein the conductor is configured to repeatedly pass through the coating device and the heating furnace in this order in the coating and drying section. The process of applying varnish while running a linear conductor in the axial direction,
The process of drying the varnish applied to the conductor in a heating furnace and
A method for manufacturing an insulated wire, which comprises a step of curing the varnish by an induction heater after the step of drying.

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