JP2011042843A - Method and apparatus for softening metallic wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for softening a metallic wire having good heating efficiency and small energy loss. <P>SOLUTION: The apparatus 3 for softening the metallic wire is provided with a softening furnace 30 covering the outer circumference of the conveyed metallic wire 9, by heating this metallic wire 9 in the softening furnace 30 to soften the metallic wire 9. This apparatus 3 for softening the metallic wire is provided with an over-heated water vapor generating device 31 for generating the over-heated water vapor and an introducing path 30c for introducing the over-heated water vapor from the over-heated water vapor device 31 into the softening furnace 30 to heat the metallic wire 9 with the over-heated water vapor filled in the softening furnace 30. Since the over-heated water vapor has large heat-capacity and high heat-conducting efficiency, the metallic wire 9 can rapidly be heated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metal wire softening method and a metal wire softening device for heating and softening a metal wire obtained by plastic working such as wire drawing. In particular, the present invention relates to a metal wire softening method and a metal wire softening device that have good heating efficiency and low energy loss.

  2. Description of the Related Art Conventionally, an enameled wire in which an outer periphery of a metal wire serving as a conductor is coated is known. The enameled wire is widely used, for example, as a wiring for various electric devices and as a winding for a motor, a transformer or the like.

  For such enameled wire, first, a metal wire having a desired linear / wire diameter is produced by a wire drawing process using a drawing die or a roller die, and after applying an insulating varnish to the metal wire, the insulating varnish is dried, It can be obtained by curing. Here, the metal wire that has undergone the wire drawing process has a high hardness due to the introduction of processing strain during the wire drawing, but lacks flexibility. Therefore, in order to make a metal wire having flexibility according to the use of the metal wire, heat treatment is performed on the metal wire to soften the metal wire.

  As a technique for softening a metal wire, for example, in Patent Document 1, an annealing pipe (softening furnace) is filled with a heated gas, and the metal wire is allowed to travel in the annealing pipe, thereby annealing (softening) the metal wire. I am letting.

JP-A-2-301521

  However, in the conventional softening furnace, since the metal wire is heated by heat conduction through the heating gas, it is necessary to heat the entire softening furnace, resulting in a large energy loss. In addition, since the heat transfer efficiency from the heated gas to the metal wire is poor, it is necessary to make the temperature of the heated gas 50 to 100 ° C. higher than the target temperature of the metal wire, resulting in a large energy loss.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal wire softening method and a metal wire softening device with high heating efficiency and low energy loss.

  The metal wire softening method of the present invention is a method of running a metal wire inside a softening furnace and heating the metal wire inside the softening furnace to soften the metal wire by superheated steam filled in the softening furnace. Is heated.

  Moreover, this invention metal wire softening apparatus is equipped with the softening furnace which covers the outer periphery of the metal wire which drive | works, and concerns on the metal wire softening apparatus which softens a metal wire by heating the said metal wire in a softening furnace. The metal wire softening device of the present invention comprises a superheated steam generator for generating superheated steam and an introduction path for introducing superheated steam from the superheated steam generator into the softening furnace, and the superheated steam filling the softening furnace. And heating the metal wire.

  Since superheated steam has higher heat transfer efficiency than the heated gas, the heated object can be heated rapidly. For example, the temperature of the superheated steam for setting the object to be heated to a desired temperature is sufficient to be almost the same as the desired temperature or about 10 ° C. higher. Therefore, according to the metal wire softening method and the metal wire softening device of the present invention, the metal wire can be efficiently heated, and there is little energy loss when the metal wire is heated.

  Moreover, the effect which removes the foreign material adhering to the surface of a metal wire can be expected by filling the inside of the softening furnace with superheated steam. For example, on the surface of the metal wire introduced into the softening furnace, the lubricant used in the wire drawing process of the metal wire, metal powder adhered to the surface of the metal wire during the wire drawing process or the running process of the metal wire, etc. Is attached as a foreign object. If the foreign matter remains on the surface of the metal wire, there may be a problem that the insulation coating is not soundly formed in the post-softening process, for example, the step of forming the insulation coating on the surface of the metal wire. On the other hand, according to the metal wire softening method and the metal wire softening device of the present invention, the removal of foreign matter can be expected simultaneously with the softening of the metal wire, so that problems caused by the foreign matter can be reduced.

  Furthermore, since oxygen can be expelled from the inside of the softening furnace by filling the inside of the softening furnace with superheated steam, the surface of the metal wire in a high temperature state can be prevented from being oxidized.

  As one form of the metal wire softening method of the present invention, it is preferable that the superheated steam introduced into the softening furnace is injected into the metal wire that is running in the softening furnace. Moreover, as a metal wire softening device of the present invention for achieving this method, a structure comprising an injection port that opens into the softening furnace at the leading end of the introduction path and injects superheated steam toward the metal wire traveling in the softening furnace It is preferable that

  According to the above configuration, the temperature of the metal wire can be quickly raised, and the metal wire can be softened efficiently and with little energy loss. Moreover, the foreign matter adhering to the surface of the metal wire can be blown away by superheated steam, and the surface of the metal wire can be cleaned. As a result, it is possible to reduce problems caused by foreign matters attached to the surface of the metal wire.

  As one aspect of the method for softening a metal wire of the present invention, the temperature of superheated steam on the inlet side of the softening furnace, which is opposite to the traveling direction of the metal wire, The temperature is preferably lower than the temperature of the water vapor. Further, as the metal wire softening device of the present invention for achieving this method, the temperature of superheated steam from the introduction path located on the inlet side of the softening furnace, which is opposite to the traveling direction of the metal wire, It is preferable that the temperature be lower than the temperature of superheated steam from the introduction path located on the outlet side of the softening furnace, which is the direction side. For example, in a softening furnace provided in a metal wire softening device, a high-temperature introduction path for introducing superheated steam at a predetermined temperature provided on the exit side of the softening furnace on the metal wire traveling direction side, and a softening furnace than the high-temperature introduction path It is good to form the low temperature introduction path which introduces the superheated steam which is provided in the entrance side of this, and has a temperature lower than the superheated steam introduced from the high temperature introduction path.

  As described above, foreign matter may adhere to the surface of the metal wire on the entrance side of the softening furnace, and in that case, there is a possibility that the foreign matter may burn on the surface of the metal wire due to high-temperature superheated steam. With the above configuration, the metal wire introduced into the softening furnace is not suddenly exposed to the high-temperature superheated steam on the entrance side of the softening furnace, and foreign substances can be prevented from scorching. The foreign matter adhering to the metal wire is removed by the superheated steam that fills the softening furnace while the metal wire travels through the softening furnace, so even if the temperature of the superheated steam is high at the outlet side of the softening furnace, Defects are unlikely to occur.

  According to the metal wire softening method and metal wire softening device of the present invention, a hardened metal wire can be efficiently softened by introducing processing strain by plastic working.

It is a schematic block diagram of an enameled wire manufacturing apparatus provided with this invention metal wire softening apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, an example will be described in which the metal wire softening device of the present invention is applied to an enamel wire manufacturing device in which an outer periphery of a metal wire as a conducting wire is enameled (insulating coating).

<Overall configuration>
An enameled wire manufacturing apparatus 100 shown in FIG. 1 includes a wire drawing device 2, a metal wire softening device 3, and an enamel coating device 4, and after drawing and softening a metal wire 9 fed out from a feeding reel 1, This is an apparatus for automatically performing an operation of forming an enamel coating on the outer periphery of the wire 9 and winding the completed enamel wire 9E around the take-up reel 5. The wire drawing device 2 provided in the enameled wire manufacturing device 100 is a device for drawing a metal wire 9 fed out from the feeding reel 1. The metal wire softening device 3 is a device that heats and softens the drawn metal wire 9. And the enamel coating apparatus 4 is an apparatus which coat | covers enamel on the outer periphery of the metal wire 9 after softening. The most characteristic feature of the enameled wire manufacturing apparatus 100 of this embodiment is the configuration of the metal wire softening device 3. Hereinafter, according to the manufacturing process of the enameled wire 9E, the devices 2 to 4 included in the enameled wire manufacturing device 100 will be described in detail.

≪Wire drawing device≫
The wire drawing device 2 is for drawing the metal wire 9 fed from the feeding reel 1 so as to have a desired linear shape and a desired wire diameter. The wire drawing device 2 includes, for example, a plurality of wire drawing dies 20a to 20d, and the metal wire 9 is gradually brought closer to a desired linear shape and wire diameter by inserting the metal wire 9 through the wire drawing dies 20a to 20d. Can do. The wire drawing dies 20a to 20d may be wire drawing dies or roller dies.

  The wire drawing device 2 may include a heating mechanism (not shown) for heating at least one of the metal wire 9 and the dies 20a to 20d in order to facilitate the processing of the metal wire 9. Moreover, when processing the metal wire 9, you may provide the lubricant supply mechanism (not shown) which makes a lubricant intervene between the metal wire 9 and dice | dies 20a-20d.

  The material of the metal wire 9 drawn by the wire drawing device 2 can be appropriately selected according to the application of the enamel wire 9E to be produced. Examples of the core material of the enameled wire 9E include Cu, Cu alloy, Al, Al alloy, and the like. Moreover, the metal wire 9 should have a wire diameter before drawing of about 20 μm to 100 mm, and may be drawn so that the wire diameter of the metal wire 9 after drawing is about 20 μm to 20 mm. . The alignment after drawing is not particularly limited, and may be, for example, an ellipse including a perfect circle or a polygon including a rectangle.

≪Metal wire softening equipment≫
The metal wire softening device 3 includes a softening furnace 30 for heating the metal wire 9 and a superheated steam generator 31 that generates superheated steam, and the metal wire 9 drawn by the wire drawing device 2 is heated with superheated steam. This is an apparatus for softening the metal wire 9 by, for example, removing processing strain introduced into the metal wire 9 by heat treatment.

  The softening furnace 30 includes a traveling path 30R in which the metal wire 9 can travel, and the metal wire 9 inserted from the entrance 30a of the traveling path 30R (softening furnace 30) is the traveling path 30R (softening furnace 30). The metal wire 9 can be heated until it exits from the outlet 30b. The softening furnace 30 is formed so that the inlet 30a side into which the metal wire 9 is introduced is high and the outlet 30b side through which the metal wire 9 is led out is low. The softening furnace 30 has a configuration in which superheated steam can be introduced therein and the metal wire 9 can be heated by the introduced superheated steam.

  The superheated steam introduced into the softening furnace 30 can be manufactured using a superheated steam generator 31 having the following configuration. For example, the superheated steam generator 31 includes a steam generator 31b such as a boiler, and a steam heating device 31h that converts the saturated steam generated in the steam generator 31b to superheated steam, and the flow of saturated steam in the steam heating device 31h. By heating the pipe which is a path, the saturated water vapor passing through the pipe can be converted into superheated water vapor. Examples of the heating method for converting the saturated water vapor into superheated water vapor include a fuel combustion method in which liquid fuel or gas fuel is combusted, and an electric heating method in which the pipe is induction-heated with high frequency. In addition, the superheated steam generator 31 may include a temperature monitoring device that monitors the temperature of the superheated steam.

  The superheated steam generated by the superheated steam generator 31 as described above is introduced into the softening furnace 30 through the introduction path 30 c of the softening furnace 30. The introduction path 30c is preferably provided at a position α on the outlet 30b side of the softening furnace 30 (running path 30R). Here, the position α on the outlet 30b side refers to a position from the end of the outlet 30b of the softening furnace 30 to 20% of the axial length of the softening furnace 30. By providing the introduction path 30c at the position α in this manner, the outlet 30b of the softening furnace 30 is positioned below the inlet 30a. Therefore, the superheated steam introduced into the softening furnace 30 on the outlet 30b side becomes the inlet 30a. Ascend to the side. As a result, the superheated steam can be spread over the entire travel path 30R in the softening furnace 30, and the metal wire 9 can be efficiently heated.

  The temperature of the superheated steam introduced into the softening furnace 30 can be in the range of 200 to 500 ° C. if it is Cu. This temperature is only the same as the temperature of the metal wire 9 required to bring the crystal structure of the metal wire 9 into a desired state or about 10 ° C., and has been conventionally used for softening the metal wire. The temperature is lower by about 50 to 100 ° C. than the temperature of the heated air. The reason why the temperature of the superheated steam can be made lower than that of the conventional heated air is because the heat transfer efficiency of the superheated steam is high, so that the heat is quickly transferred from the superheated steam to the metal wire. Further, as an advantage of using superheated steam, heat is transferred from the superheated steam to the metal wire 9 quickly, so that the length of the softening furnace 30 is made shorter or the wire speed of the metal wire 9 is made larger than before. Can be mentioned. When the softening furnace 30 is shortened, the configuration of the enameled wire manufacturing apparatus 100 can be reduced in size, and when the linear velocity is increased, the productivity of the enameled wire 9E can be improved. In addition, as an advantage of using the superheated steam, when the superheated steam is filled in the softening furnace 30, oxygen is expelled from the softening furnace 30, so that the surface of the metal wire 9 can be effectively prevented from being oxidized. .

  As described above, from the viewpoint of spreading superheated steam in the softening furnace 30, it is preferable to use a plurality of introduction paths 30c. When a plurality of introduction paths 30c are provided, at least one of them may be provided at a position α on the outlet 30b side of the softening furnace 30 for the same reason as described above. As for the remaining introduction paths, for example, an intermediate position β in the axial direction of the softening furnace 30 and a position γ on the inlet 30a side of the softening furnace 30 can be cited. Here, the position γ on the inlet 30a side refers to a position from the end of the inlet 30a of the softening furnace 30 to 30% of the axial length of the softening furnace 30, and the intermediate position β is a position other than the positions α and β. . More preferably, the introduction path is preferably provided at three positions, that is, position α on the outlet 30b side, intermediate position β, and position γ on the inlet 30a side. In addition, a plurality of introduction paths 30c may be disposed so as to surround the metal wire 9 in the circumferential direction at substantially the same position in the axial direction of the softening furnace 30 (running path 30R). Can be heated. Of course, a plurality of introduction paths 30c may be provided so as to surround the outer periphery of the metal wire 9 at a plurality of positions in the axial direction of the softening furnace 30.

  As described above, as an advantage of providing a plurality of introduction paths 30c, the temperature of the superheated steam in each introduction path 30c can be varied. In that case, it is preferable to lower the temperature of the superheated steam from the introduction path 30c at other positions β and γ than the temperature of the superheated steam from the introduction path 30c at the position α on the outlet 30b side. This is because the lubricant and metal powder adhering in the wire drawing process adhere to the surface of the metal wire 9 immediately after being introduced into the softening furnace 30, so that the lubricant and metal powder are heated by high-temperature superheated steam. This is because there is a risk of seizing. That is, if the surface of the metal wire 9 is cleaned with relatively low-temperature superheated steam on the inlet 30a side, even if the metal wire 9 is exposed to high-temperature superheated steam on the outlet 30b side of the softening furnace 30, the lubricant It is difficult to cause problems such as image sticking. For example, the temperature of the superheated steam introduced from the introduction path 30c on the inlet 30a side into the travel path 30R is preferably 500 ° C. or less.

  In order to further enhance the effect of cleaning the surface of the metal wire 9, it is preferable that the superheated steam introduced from the introduction path 30 c is jetted onto the surface of the metal wire 9. For example, an injection nozzle (injection port) may be provided at the tip of the introduction path 30 c so that the injection nozzle opens toward the metal wire 9 in the softening furnace 30. Further, in order to enhance the above-described cleaning effect, in addition to providing an injection nozzle at the tip of the introduction path 30c, the introduction path 30c may be disposed so as to surround the metal wire 9 in the circumferential direction.

  The metal wire softening device 3 described above may further include a refrigerant tank 32 filled with a liquid refrigerant (typically pure water) in the vicinity of the outlet 30 b of the softening furnace 30. The refrigerant tank 32 is for cooling the metal wire 9 heat-treated in the softening furnace 30, and prevents the surface of the high-temperature metal wire 9 from being oxidized. By configuring the liquid refrigerant in the refrigerant tank 32 to circulate constantly, the metal wire 9 can be efficiently cooled.

≪Enamel coating equipment≫
The enamel coating apparatus 4 includes a turning mechanism 40, a coating mechanism 41, and a baking furnace 42.

  The encircling mechanism 40 provided in the enamel coating apparatus 4 has pulleys 40d and 40u that are vertically opposed to each other, and is a mechanism that circulates the metal wire 9 spanned between the pulleys 40d and 40u. Here, in FIG. 1, only one pulley 42d and 42u is shown, but in reality, a plurality of pulleys 42d and 42u are arranged in parallel on the back side of the paper surface, and the pulleys 42d and 42u for sequentially passing the metal wires 9 are on the back side of the paper surface. The metal wire 9 can be made to circulate by shifting. The metal wire 9 that has been wound around a predetermined number of times and has the surface covered with enamel, that is, the enamel wire 9E, is finally wound around the take-up reel 5.

  The coating mechanism 41 includes an insulating varnish tank 41t that stores the insulating varnish and a coating die 41d through which the metal wire 9 that has passed through the insulating varnish tank 41t is inserted, and applies the insulating varnish to the outer periphery of the metal wire 9 that circulates. Mechanism. A rotating metal wire 9 passes through the bottom of the insulating varnish tank 41t, and the insulating varnish is applied to the outer periphery of the metal wire 9 that has passed through the insulating varnish tank 41t. The insulating varnish applied to the outer periphery of the metal wire 9 is adjusted to have a substantially uniform thickness by passing the metal wire 9 through the application die 41d on the metal wire 9 traveling direction side of the insulating varnish tank 41t. . A plurality of the coating dies 41d are arranged on the back side of the paper, and the diameter of the die hole increases toward the back of the paper, and the enamel coating formed on the outer periphery of the metal wire 9 is gradually thickened to be uniform. The thickness of the enamel coating can be as small as possible.

  The baking furnace 42 includes a traveling path 42R that accommodates a part of the metal wire 9 that circulates therein, and heats the metal wire 9 that is coated with the insulating varnish that travels in the traveling path 42R, and is included in the insulating varnish. The solvent is volatilized and the resin contained in the insulating varnish is cured to fix the enamel coating on the outer periphery of the metal wire 9. Here, the baking furnace 42 preferably has a higher outlet 42b than the inlet 42a of the baking furnace 42 (travel path 42R) in order to prevent the insulating varnish from drooping due to gravity. More preferably, the baking furnace 42 is in an inverted state in which the traveling path 42R is vertical with the outlet 42b facing upward, as shown.

  The structure which heats the metal wire 9 with an insulating varnish which goes around the running path 42R of the baking furnace 42 can be selected as appropriate. For example, an introduction path 42c may be formed in the vicinity of the inlet 42a of the baking furnace 42 (travel path 42R), and heated air may be introduced from this introduction path 42c, or superheated steam as in the metal wire softening device 3 of the present invention. May be introduced. The heated air or superheated steam introduced from the inlet 42a rises toward the outlet 42b, and can heat the metal wire 9 traveling in the traveling path 42R over the entire area in the axial direction of the traveling path 42R.

<Effect>
According to the enameled wire manufacturing apparatus 100 described above, since the metal wire 9 can be efficiently softened by the metal wire softening device 3 of the present invention, the enameled wire 9E can be produced more efficiently than before. Can do. For example, the manufacturing time of the enameled wire 9E can be shortened by making the softening furnace 30 shorter than before or by increasing the traveling speed (linear speed) of the metal wire 9. Further, when the metal wire 9 is softened, the surface of the metal wire 9 can be cleaned and oxygen on the surface of the metal wire 9 can be effectively prevented, so that the occurrence of defective products can be suppressed.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.

  The metal wire softening device and the metal wire softening method of the present invention can be suitably used for producing enameled wires.

DESCRIPTION OF SYMBOLS 100 Enamel wire manufacturing apparatus 1 Feeding reel 2 Wire drawing apparatus 20a-20d Wire drawing die 3 Metal wire softening apparatus 30 Softening furnace 30a Inlet 30b Outlet 30c Introduction path 30R Traveling path 31 Superheated steam generator 31b Steam generator 31h Steam heating apparatus 32 Refrigerant layer 4 Enamel coating device 40 Circulation mechanism 40d, 40u Pulley 41 Coating mechanism 41t Insulated varnish tank 41d Coating die 42 Baking furnace 42a Inlet 42b Outlet 42c Inlet path 42R Travel path 5 Take-up reel 9 Metal wire 9E Enamel wire

Claims (5)

A method of running a metal wire inside the softening furnace and heating the metal wire inside the softening furnace to soften the wire,
A method for softening a metal wire, comprising heating the metal wire with superheated steam filled in the softening furnace.   The method of softening a metal wire according to claim 1, wherein the superheated steam is sprayed onto the metal wire that is traveling in the softening furnace.   The method for softening a metal wire according to claim 1 or 2, wherein the temperature of the superheated steam on the inlet side of the softening furnace is lower than the temperature of the superheated steam on the outlet side of the softening furnace. A metal wire softening device comprising a softening furnace covering the outer periphery of a traveling metal wire, and softening the metal wire by heating the metal wire in the softening furnace,
A superheated steam generator for generating superheated steam;
An introduction path for introducing superheated steam from the superheated steam generator into the softening furnace,
The said softening furnace heats a metal wire with the superheated steam with which the inside was filled, The metal wire softening apparatus characterized by the above-mentioned.   5. The metal wire according to claim 4, further comprising an injection port that opens into the softening furnace at a tip of the introduction path and injects the superheated steam toward the metal wire traveling in the softening furnace. Softening device.

Images