JP7404991B2 - Copper wire manufacturing equipment - Google Patents

Description

The present invention relates to a copper wire manufacturing apparatus equipped with a casting ring.

One method for manufacturing copper wire is to flow molten copper material (molten copper) into a space between a belt and a groove provided on the outer peripheral surface of a casting ring whose rotation axis is horizontal. There is a known method of casting a cast bar made of copper material by cooling the molten copper after that. By rolling the cast bar in a subsequent process, copper wire (copper rough drawn wire) can be manufactured.

Patent Document 1 (International Publication No. 2012/096238) describes a method of continuously casting copper or a copper alloy by a belt and wheel method as a method for manufacturing a copper alloy wire.

International Publication No. 2012/096238

The molten copper poured into the groove of the casting ring solidifies in a curved shape along the curved surface of the outer circumferential surface of the casting ring, and becomes a cast bar.After that, the cast bar separated from the casting ring is straightened. Ru. For this reason, when the cast bar is changed from a curved shape to a straight line, tensile stress is generated in the part of the cast bar that was located on the bottom side of the casting ring (lower surface part), and Compressive stress is generated in the portion (upper surface portion) located on the opposing belt side. For example, when the diameter of the casting ring is about 2500 mm, the curvature of the cast bar cast into a curved shape becomes small, so the stress generated in the upper and lower surface parts of the straight cast bar is reduced. growing. For this reason, when attempting to cast a cast bar using a casting ring having the diameter as described above, there is a risk that the cast bar will crack due to the stress.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copper wire manufacturing apparatus that makes it difficult for a cast bar to crack.

A brief overview of typical embodiments disclosed in this application will be as follows.

A copper wire manufacturing apparatus according to an embodiment is a copper wire manufacturing apparatus including a casting section that casts a casting bar using a casting ring that rotates around a rotation axis, and the casting ring has a casting ring that is formed on the outer periphery of the casting ring. a groove for casting the casting bar formed in an annular shape along the casting ring; The diameter b of the circle is 33 times or more and 56 times or less.

According to one embodiment disclosed in this application, it is possible to provide a copper wire manufacturing apparatus that can make it difficult for cracks to occur in a cast bar.

1 is a schematic diagram of a copper wire manufacturing apparatus according to an embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. FIG. 2 is an enlarged schematic view showing the vicinity of the casting ring shown in FIG. 1. FIG. FIG. 2 is an enlarged schematic view showing the vicinity of the casting ring shown in FIG. 1. FIG. FIG. 2 is an enlarged schematic diagram showing the vicinity of a cast ring of a comparative example.

Hereinafter, embodiments will be described in detail based on the drawings. In addition, in all the drawings for explaining the embodiment, members having the same function are given the same reference numerals, and repeated explanation thereof will be omitted. Furthermore, in the following embodiments, descriptions of the same or similar parts will not be repeated in principle unless particularly necessary.

The copper wire manufacturing apparatus of this embodiment forms a casting ring having a relatively large diameter and having a groove along the outer peripheral surface. The following describes a copper wire manufacturing apparatus that uses a casting ring with a large diameter to cast a cast bar with a low oxygen concentration while preventing the occurrence of cracks.

<Structure of copper wire manufacturing equipment and copper wire manufacturing method>
The structure of the copper wire manufacturing apparatus and the copper wire manufacturing method of this embodiment will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 1, the copper wire manufacturing apparatus 10 according to the present embodiment is a so-called continuous casting and rolling apparatus for continuously casting and rolling copper wire (copper rough drawn wire), and includes, for example, a melting furnace 210, Upper gutter 220, holding furnace 230, addition section 240, lower gutter 260, tundish 300, pouring nozzle 320, continuous casting machine 500, hot rolling device 620, winding machine (coiler) 640.

The melting furnace 210 heats and melts a copper raw material to produce molten copper 110, and includes, for example, a furnace body and a burner provided at the lower part of the furnace body. Copper raw material is introduced into the furnace body and heated by a burner, so that molten copper 110 is continuously generated. As the copper material, for example, copper (Cu) or the like can be used. Molten copper contains oxygen (O).

The upper gutter 220 is provided on the downstream side of the melting furnace 210, connects the melting furnace 210 and the holding furnace 230, and transfers the molten copper 110 generated in the melting furnace 210 to the holding furnace 230 on the downstream side. It is.

The holding furnace 230 is provided on the downstream side of the upper gutter 220, and heats the molten copper 110 transferred from the upper gutter 220 at a predetermined temperature and temporarily stores it. Further, the holding furnace 230 transfers a predetermined amount of molten copper 110 to the lower gutter 260 while maintaining the molten copper 110 at a predetermined temperature. The addition section 240 is for continuously adding a predetermined metal element to the molten copper 110 in the lower gutter 260. Examples of the metal elements added to the molten copper 110 include tin (Sn), indium (In), titanium (Ti), magnesium (Mg), silver (Ag), aluminum (Al), calcium (Ca), or manganese. (Mn) and the like. That is, preferably, at least one of these metal elements is added to the molten copper 110.

The lower gutter 260 is provided on the downstream side of the holding furnace 230, and is used to transfer the molten copper 110 transferred from the holding furnace 230 to the tundish 300 on the downstream side. The addition section 240 is connected to the lower gutter 260 . Note that the addition section 240 is not limited to the mode in which it is connected to the lower gutter 260, but may be connected to the holding furnace 230 or the tundish 300, for example.

The tundish 300 is provided on the downstream side of the lower gutter 260, temporarily stores the molten copper 110 transferred from the lower gutter 260, and continuously supplies a predetermined amount of molten copper 110 to the continuous casting machine 500. It is something to do. In this way, molten copper 110 to be supplied to continuous casting machine 500 is prepared.

A pouring nozzle 320 for flowing out the stored molten copper 110 is connected to the downstream side of the tundish 300. Molten copper 110 accumulated in tundish 300 is supplied to continuous casting machine 500 via pouring nozzle 320.

The continuous casting machine 500 is a device that performs so-called belt-wheel continuous casting, and includes, for example, a casting ring (casting wheel) 1 and a belt 3. A cylindrical cast ring 1 has a groove 2 (see FIG. 2) on its outer periphery. The casting ring 1 rotates during the copper wire manufacturing process, and its rotation axis 6 is along a horizontal plane. A cylindrical holding part 5 that holds the casting ring 1 is arranged inside the cylindrical casting ring 1 . The casting ring 1 is fixed to the holding part 5 and rotates together with the holding part 5. Note that the casting ring 1 may be cylindrical or disc-shaped.

Further, the belt 3 is configured to move around while contacting a part of the outer peripheral surface of the casting ring 1. Molten copper 110 flowing out from the tundish 300 is poured into the space between the groove 2 of the casting ring 1 and the belt 3. That is, the tundish 300 and the pouring nozzle 320 are a supply section 330 that supplies the molten copper 110 into the groove 2 of the casting ring 1. Further, the casting ring 1 and the belt 3 are cooled by, for example, cooling water. As a result, the molten copper 110 is cooled and solidified (solidified), and rod-shaped casting bars (casting material) 120 are continuously cast. That is, the continuous casting machine 500 equipped with the casting ring 1 is a casting section that solidifies molten copper 110 and casts a casting bar 120.

The hot rolling device 620 is a rolling section that is provided on the downstream side (cast bar discharge side) of the continuous casting machine 500 and continuously rolls the cast bar 120 transferred from the continuous casting machine 500 to form a rolled material. be. That is, the hot rolling device 620 is used to pull out the casting bar 120 from the groove 2 of the casting ring 1 and transfer it to the outside of the continuous casting machine 500. The rolled material formed by rolling the cast bar 120 by the hot rolling device 620 is surface-cleaned between the hot rolling device 620 and the winding machine 640, thereby forming the copper wire (rough copper wire) 130. is cast.

A winder (coiler) 640 is provided on the downstream side (copper alloy material discharge side) of the hot rolling device 620, and winds up the copper wire 130 transferred from the hot rolling device 620 via the surface cleaning treatment device. It is something. Through the above steps, the copper wire (rough copper wire) 130 can be formed.

Here, the cast bar 120 taken out from the casting ring 1 shown in FIG. 1 and before being rolled in the hot rolling apparatus 620 contains oxygen. Similarly, the copper wire 130 also contains oxygen. The oxygen content (oxygen content concentration) in the copper of each of the cast bar 120 and the copper wire 130 is 450 mass ppm or less. From the viewpoint of increasing the hardness of the copper wire to be manufactured, a more preferable value of the oxygen content is 120 mass ppm or less.

Next, the specific structure of the outer peripheral part of the cast ring will be described using FIG. 2. FIG. 2 is a cross-sectional view of the casting ring 1 along the rotation axis (hereinafter simply referred to as the rotation axis) 6, and FIG. 2 shows the casting ring 1, the belt 3 that covers the outer circumference of the casting ring 1, and the holding part It shows. FIG. 2 is a cross-sectional view taken along line AA in FIG. In FIG. 2, neither the molten copper nor the cast bar is shown.

On the outer side surface of the casting ring 1 in the radial direction (hereinafter simply referred to as the radial direction), that is, on the outer peripheral surface, a groove (recess) 2 recessed toward the rotating shaft 6 side is formed in an annular shape along the outer periphery of the casting bar. It is formed. The groove 2 extends along the outer periphery (circumferential direction) of the casting ring 1 and is formed in an annular shape so as to surround the rotating shaft 6 . The width of the groove 2 in the direction along the rotating shaft 6 (also referred to as the rotating shaft direction) gradually decreases from the outer peripheral side of the casting ring 1 toward the rotating shaft side 6. In other words, the cross-sectional shape of the groove 2 is an inverted trapezoid. Since the cross-sectional shape of the groove 2 is an inverted trapezoid, the cast bar 120 (see FIG. 1) solidified within the groove 2 can be easily taken out from the groove 2.

Although not shown here, the surface of the groove 2 is continuously covered with a refractory film made of soot called soot. Further, among the surfaces of the belt 3, the surface facing the bottom surface of the casting ring 1 is covered with a refractory film made of soot called soot.

The cast ring 1 is mainly made of copper (Cu), for example. The cast ring 1 may be made of copper mixed with chromium (Cr), zirconium (Zr), or the like. The molten copper 110 injected into the space between the belt 3 and the outer peripheral surface of the casting ring 1 (inside the groove 2) loses heat to the casting ring 1, which mainly contains copper, which has a relatively high thermal conductivity. By being cooled by this, it solidifies before going around the casting ring 1 once.

As shown in FIGS. 1 and 2, the diameter a of the cast ring 1 is the maximum width of the cast ring 1 in the radial direction. In other words, the diameter a of the casting ring 1 is the diameter of a surface of the casting ring 1 perpendicular to the rotational axis direction. One of the main features of this embodiment is that the diameter a of the cast ring 1 is relatively large, being 2900 mm or more and 3500 mm or less. More preferably, the diameter a of the casting ring 1 is greater than 2900 mm and less than or equal to 3200 mm.

Further, the cross-sectional area of the cast bar 120 of this embodiment is 3000 mm ² or more and 6000 mm ² or less. More preferably, the cross-sectional area of the cast bar 120 is greater than 3000 ^mm2 and less than or equal to 4000 ^mm2 . At this time, when copper wire is manufactured using the copper wire manufacturing apparatus 10 of this embodiment, the casting capacity is, for example, 20 tons or more and 30 tons or less per hour. The cross-sectional area of the cast bar in this application is the area of a cross section perpendicular to the longitudinal direction of the cast bar.

Here, assuming that the cross-sectional area of the cast bar 120 of this embodiment is 3000 mm ² or more and 6000 mm ² or less, assuming a circle having the cross-sectional area, the diameter b of the circle is approximately 62 to 87 mm. .4mm. Therefore, assuming that the diameter a of the cast ring 1 is 2900 mm or more and 3500 mm or less, the range of the ratio of the diameter a to the diameter b is expressed as 33 to 56.

That is, in the copper wire manufacturing apparatus of this embodiment, the ratio of the diameter a of the casting ring 1 to the diameter b of a circle having the same cross-sectional area as the casting bar 120 ranges from 33 to 56. In other words, the diameter a is 33 times or more and 56 times or less larger than the diameter b.

FIG. 3 shows the casting ring 1 and its vicinity that constitute the copper wire manufacturing apparatus 10 during the copper wire manufacturing process. As shown in FIG. 3, molten copper 110 is poured from a pouring nozzle 320 into the space between the belt 3 and the groove on the outer periphery of the casting ring 1. That is, FIG. 3 shows a cross section of the casting ring 1, and the surface of the casting ring 1 where the casting ring 1 and the molten copper 110 are in contact with each other via a refractory film (not shown) is shown in FIG. 2 is the bottom surface of the groove 2 shown in FIG. The bottom surface of the cast ring 1 in the present application refers to the bottom surface of the groove 2, that is, the surface on the rotating shaft 6 side among the surfaces forming the groove 2.

The casting ring 1 is rotating together with the molten copper 110 and the casting bar 120 in the direction of the arrow. Further, the belt 3 is also moving at the same speed as the outer peripheral surface of the casting ring 1. The cast bar 120 is taken out of the casting ring 1 in a curved shape, is made into a straight shape, and is then rolled by the hot rolling machine 620 as explained using FIG.

Inside the casting bar 120 that is in contact with the casting ring 1 and rotating together with the casting ring 1, compressive stress is generated in the vicinity of the lower surface portion located on the bottom side of the casting ring 1, and It is considered that tensile stress is generated near the upper surface portion located on the opposite side (belt 3 side). On the other hand, the cast bar 120 taken out from the casting ring 1 and deformed from a curved shape to a straight shape has an opposite stress inside due to the deformation. In other words, inside the cast bar 120 that has been straightened after being taken out from the cast ring 1, tensile stress is generated near the lower surface portion that was placed on the bottom side of the cast ring 1, and Compressive stress is generated in the vicinity of the upper surface portion located on the belt 3 side. Here, the tensile stress occurring in the lower surface portion of the straightened cast bar 120 is smaller than the compressive stress occurring in the upper surface portion.

As described above, the copper wire manufacturing apparatus of this embodiment includes a casting section that casts a casting bar 120 using a casting ring 1 (see FIG. 4) that rotates around a rotating shaft 6. It is. This copper wire manufacturing apparatus has a groove formed in an annular shape along the outer periphery of a casting ring 1. The diameter (first diameter) a, which is the maximum width in the radial direction of the casting ring 1, is the diameter of a circle (second diameter) that is 2900 mm or more and has the same area as the cross-sectional area of the casting bar 120 cast in the casting ring 1. It is 33 times or more and 56 times or less larger than b.

<Effects of this embodiment>
As a comparative example, FIG. 5 illustrates a case in which a cast bar is cast using a casting ring having a relatively small diameter. FIG. 5 is an enlarged schematic diagram showing the vicinity of a cast ring of a comparative example. The configuration of the copper wire manufacturing apparatus of the comparative example is similar to the configuration of the copper wire manufacturing apparatus 10 shown in FIG. 1, except that the diameter of the casting ring is relatively small. Also in the comparative example, the cross-sectional area of the casting bar 120 cast using a casting ring is assumed to be 3000 mm ² or more and 6000 mm ² or less, as in the present embodiment.

The diameter c of the cast ring 4 of the comparative example shown in FIG. 5 is less than 2900 mm. The diameter c is, for example, about 2500 mm, which is relatively small. When the cast bar 120 cast with such a casting ring 4 is straightened, tensile stress is generated in the lower surface portion and compressive stress is generated in the upper surface portion, as explained using FIG. 4. At this time, since the diameter c of the casting ring 4 is relatively small, about 2500 mm, when the casting bar 120 is cast using such a casting ring 4, the upper surface portion and the lower surface portion of the straightened casting bar 120 are separated. The above-mentioned stress generated in each of the above increases. Specifically, the tensile stress generated in the lower surface portion of the straightened cast bar 120 is greater than the compressive stress generated in the upper surface portion. Therefore, there is a possibility that cracks may occur in the lower surface portion of the straightened casting bar 120.

Furthermore, for the purpose of increasing the hardness of copper wire, it is conceivable to cast a cast bar made of copper with a low oxygen content. However, as the oxygen content of the cast bar decreases, the cast bar becomes harder and more brittle. For example, when the oxygen content of a cast bar becomes 450 mass ppm or less, the cast bar becomes susceptible to cracking due to stress generated inside the cast bar. In particular, when the oxygen content of the cast bar reaches 50 to 120 mass ppm, the cast bar becomes very brittle and easily cracks due to stress generated inside the cast bar.

Therefore, if a cast bar with a low oxygen content is cast using a casting ring 4 having a small diameter c as in the comparative example, there is a risk that cracks may occur in the cast bar 120 when the cast bar 120 is straightened. Such cracks remain as defects in the wire even after the cast bar 120 is rolled. In addition, if the cracks in the cast bar 120 are large (especially if the cracks detected by visual observation of the cast bar 120 are 1 cm or more from the surface of the cast bar 120 to the center of the cast bar 120), rolling In this case, the casting bar 120 may break.

If the copper wire 130 is manufactured with the above-mentioned cracks remaining on the surface of the cast bar 120, many scratches will occur on the surface. Therefore, we will draw the copper wire 130 with many scratches on its surface (copper wire with 50 or more scratches of 1.5V or higher detected when its surface is detected using a commercially available eddy current flaw detector) in the next process. In this case, cracks or breaks occur in the drawn wire material starting from defects caused by cracks during casting, resulting in a decrease in yield. Furthermore, if the cast bar 120 breaks due to cracks in the cast bar 120, it may cause equipment failure. Therefore, if the cast bar 120 breaks due to cracking, it becomes necessary to stop the operation of the copper wire manufacturing apparatus and restart the copper wire manufacturing operation. For this reason, the time required to manufacture the copper wire using the copper wire manufacturing apparatus increases, and the manufacturing cost increases. That is, a copper wire manufacturing apparatus in which such cracking of the cast bar 120 and breakage caused by the cracking easily occurs has a problem of low copper wire manufacturing ability and low reliability.

Furthermore, the cast bar 120 containing metal other than copper is considered to be more likely to break than the cast bar 120 containing no such metal and having high copper purity. The metal elements added to the cast bar 120 include, for example, tin (Sn), indium (In), titanium (Ti), magnesium (Mg), silver (Ag), aluminum (Al), calcium (Ca), or manganese ( Mn) etc. Cast bar 120 containing such a metal is likely to suffer from problems due to cracking as described above.

On the other hand, in the copper wire manufacturing apparatus 10 of the present embodiment, as shown in FIG. A cast ring 1 having a diameter is used. The cast ring 1 having such a large diameter a has a larger curvature of the outer circumferential surface than the comparative example shown in FIG. For this reason, when the cast bar 120 taken out from the casting ring 1 is changed from a curved shape to a straight shape, it is possible to prevent the tensile stress in the lower surface portion inside the cast bar 120 from becoming larger than the compressive stress in the upper surface portion. . Therefore, for example, even if the cast bar 120 has an oxygen content of 450 mass ppm or less, the cast bar 120 may have cracks (cracks detected by visual observation of the cast bar 120) when it is changed from a curved shape to a straight shape. 1 cm or more from the surface of the cast bar 120 to the center of the cast bar 120) or breakage is less likely to occur. Then, by rolling the cast bar 120 obtained in this way using a hot rolling device 620, a copper wire 130 with fewer cracks on the surface can be obtained. Note that the copper wire 130 with few cracks on the surface is a copper wire in which the number of flaws of 1.5 V or more detected is 10 or less when the surface of the copper wire 130 is tested with a commercially available eddy current flaw detector. . Further, in the copper wire manufacturing apparatus 10 of the present embodiment, even if the cast bar 120 has an oxygen content of 120 mass ppm or less, cracking or breakage of the cast bar 120 can be prevented. Further, in the copper wire manufacturing apparatus 10 of the present embodiment, even if the cast bar 120 to be cast contains a metal element other than copper, cracking and breakage can be prevented from occurring.

If you try to cast a cast bar with a cross-sectional area of 3000 mm ² or more and 6000 mm ² or less using the copper wire manufacturing apparatus of the comparative example, there is a risk that the cast bar will break. For example, even if cast bars having similar cross-sectional areas are cast, the cast bars are less likely to crack.

Here, assuming that the cross-sectional area of the cast bar 120 of this embodiment is 3000 mm ² or more and 6000 mm ² or less, assuming a circle having the cross-sectional area, the diameter b of the circle is approximately 62 to 87 mm. .4mm. Therefore, assuming that the diameter a of the cast ring 1 is 2900 mm or more and 3500 mm or less, the range of the ratio of the diameter a to the diameter b is expressed as 33 to 56.

In other words, the diameter a of the cast ring 1 is 2900 mm or more, and the ratio of the diameter a of the cast ring 1 to the diameter b of a circle having the same area as the cross-sectional area of the cast bar 120 is in the range of 33 to 56. By using a manufacturing apparatus, the effects of this embodiment can be obtained.

In other words, by making it difficult for the cast bar to crack and prevent the cast bar from breaking, it is possible to prevent yield deterioration due to cracking or breakage during wire drawing, and to allow copper wire manufacturing equipment to operate without stopping. . In other words, it is possible to improve the ability of the copper wire manufacturing apparatus to manufacture copper wire, and further improve the reliability of the copper wire manufacturing apparatus. Moreover, the manufacturing cost of copper wire can be reduced. In particular, the above effects can be obtained when manufacturing copper wires with low oxygen content and high hardness, and when manufacturing copper wires containing metals other than copper.

As above, the invention made by the present inventors has been specifically explained based on the embodiments, but the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the gist thereof. Needless to say.

1, 4 Casting ring 2 Groove 3 Belt 5 Holding section 6 Rotating shaft 10 Copper wire manufacturing device 110 Molten copper 120 Casting bar 130 Copper wire 300 Tundish 330 Supply section 500 Continuous casting machine (casting section)
620 Hot rolling equipment (rolling section)
a Diameter (first diameter)

Claims (3)

A copper wire manufacturing apparatus comprising: a casting section that casts a cast bar made of copper material using a casting ring that rotates around a rotating shaft; and a rolling section that rolls the cast bar to form a rolled material. hand,
The casting ring has a groove formed in an annular shape along its outer periphery for casting the casting bar,
The diameter a of the casting ring is 2900 mm or more and 3200 mm or less, and is 33 times or more and 56 times or less larger than the diameter b of a circle having the same area as the cross-sectional area of the casting bar to be cast with the casting ring. have,
The copper wire manufacturing apparatus , wherein the cast bar has an oxygen content of 450 mass ppm or less . The copper wire manufacturing apparatus according to claim 1,
A copper wire manufacturing apparatus, wherein the cast bar has a cross-sectional area of 3000 mm ² or more and 6000 mm ² or less. The copper wire manufacturing apparatus according to claim 1 or 2 ,
The copper wire manufacturing apparatus, wherein the casting bar contains tin, indium, titanium, magnesium, silver, aluminum, calcium or manganese.

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