JPS636289B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method and apparatus for cooling a wire rod after hot rolling, and more specifically, to a state in which a wire rod after hot rolling is continuously shifted in one direction at regular intervals and stacked on top of each other in a group of rings (hereinafter referred to as a wire rod coil). The present invention relates to a method and apparatus for cooling by forced air blast while being placed and transferred on a conveyor. Controlled cooling methods for directly heat-treating a wire immediately after hot rolling using the rolling heat of the wire are widely known, and many methods have already been proposed and put into practical use. Among these, a typical processing method is to feed the hot-rolled wire into a coil using a winding machine, which is then received on a transfer conveyor such as a chain conveyor, where the wire is shifted at regular intervals and overlapped with each other. The most well-known method is to place and transport a group of rings, and cool the wire by blowing air from the lower part of the conveyor onto the wire coil during the transport (Japanese Patent Publication No. 15463/1983). However, as of late, better quality,
In particular, there is a problem that the above-mentioned lower blast method cannot satisfactorily meet the requirement of reducing the variation in the mechanical properties of the wire coil in the width direction. In other words, since the wire rod shape on the transfer conveyor has to take the above-mentioned overlapping state of wire rod rings, the overlapping density of the wire rods at both edges of the wire rod coil is larger than that at the center portion, forming a dense layered portion. For,
If the same amount of blast air is simply blown in the width direction of the coil, the cooling rate in the dense layer region will naturally be lower than in other parts, and the cooling rate in the width direction of the coil will be uneven, resulting in large variations in quality. Of course, we have been aware of the uneven cooling rate caused by differences in the density of wire coils in the past, and we have tried to resolve this by increasing the number of blasts that blow on both edges, but even with this, there is still variation. The reality is that it has not yet been possible to reduce the Several specific proposals have been made in the past to solve these problems, but most of them are based on the above-mentioned bottom blast method. For example, there is a technique disclosed in Japanese Patent Publication No. 52-32321 as a cooling method that uses the bottom blast method as it is and also sprays cooling fluid from the side as an auxiliary cooling means. Further, as another example, in order to solve the problem of insufficient cooling of both edges of a wire coil, many methods have been proposed for mechanically separating both edges. However, as mentioned above, most of these proposals are based on the above-mentioned bottom blast method;
There are disadvantages in terms of equipment and operation, and the cooling rate in the width direction of the wire coil is not uniform to a satisfactory extent. Furthermore, with regard to methods of unraveling wire rods by mechanical means, there are concerns about the effects on quality such as generation of flaws, and workability when converging wire rod coils, and there are few methods that have been put to practical use. The problems of the above-mentioned conventional techniques can be summarized as follows. (1) Mechanically separating both edges of a wire coil is disadvantageous in terms of workability, quality, etc., so we will establish a method that enables uniform cooling of the wire by only spraying cooling fluid. thing. (2) When using cooling fluid spraying means, spraying the cooling fluid only from the lower surface of the wire coil is insufficient because the cooling rate of both edges of the wire coil becomes slow. (3) In addition to spraying cooling fluid from the bottom surface, the method of spraying cooling fluid from the sides of both edges of the wire coil is undesirable in terms of equipment costs and operation. The cooling fluid that passes through the coil and blows toward the upper surface blocks or weakens the cooling fluid that is blown from the sides of both edges of the wire coil, making it impossible to obtain the desired cooling effect. Based on the above points, the present inventors have found that in order to uniformly cool the wire coil in the width direction, it is necessary to form a flow velocity distribution with a larger flow velocity from the center of the wire coil in the width direction toward both edges. They focused on this fact and found that it is effective to spray the cooling fluid only from the sides of both edges of the wire coil in order to achieve this. This spraying of cooling fluid only from the sides (hereinafter simply referred to as side spraying) is particularly effective in cooling both edges of the wire coil, which has a large overlap density. big. The purpose of the present invention is to be able to uniformly cool the entire width of the wire coil by side spraying, and thereby to suppress the variation in quality in the width direction of the coil to a small range that is difficult to achieve in the past. An object of the present invention is to provide a method for cooling a hot rolled wire rod. Another object of the present invention is to provide a method for cooling hot-rolled wire rods in which a desired flow velocity distribution can be obtained by appropriately selecting the spraying angle and spraying position of the cooling fluid or the relationship between each spraying fluid during side spraying. It's about doing. Furthermore, another object of the present invention is to provide a cooling device for hot rolled wire that can effectively carry out the above cooling method and is advantageous in terms of equipment. The details of the present invention will be explained below. First, a conventional method in which cooling fluid is sprayed only from the lower surface of a wire coil will be explained, and then the process of obtaining the configuration of the present invention will be explained in sequence. When the cooling fluid is sprayed only from the lower surface of the wire coil, the cooling rate distribution in the width direction of the wire coil takes on a mountain shape as shown by the chain line in FIG. 1A. In order to increase the cooling speed of both edges of the coil, it is necessary to further increase the flow rate of the fluid blown from the bottom surface of both edges, but since the edges of the wire coil have a large overlap density, the cooling fluid is It is difficult for the flow to flow around the upper surface of the coil edge, and a considerable increase in flow rate is required to increase the average cooling rate.In that case, the cooling rate on the lower surface becomes extremely high, and in the end it becomes almost impossible to uniformly cool the wire coil. Become. In addition, when the cooling fluid is sprayed on the bottom surface, the distribution of the tensile strength in the width direction of the wire coil is approximately the first
The pattern will be as shown in Figure B. This is an example of SWRH72A 5.5mmφ specified by JIS. As can be seen from FIG. 1B, the distribution of tensile strength also shows that due to the above-mentioned chevron-shaped cooling rate pattern, the dispersion is quite large at both ends, as well as at both ends. In the present invention, side spraying is used in place of this bottom spraying, and this side spraying basically targets the main line of the sprayed fluid on the side surface of the wire coil near the edge of the coil. That is, when the target position is near the edge, the blown cooling fluid first cools the edge of the wire coil, then diffuses toward the center in the width direction of the coil, and continues cooling while gradually decreasing the flow velocity. An example of the flow velocity distribution in the width direction of the wire coil at this time is shown in FIG. In addition, when measuring the flow velocity of this cooling fluid,
In order to measure the flow velocity, which has more technical meaning in terms of cooling the wire coil, the present inventors placed a wire coil at approximately room temperature on a transfer conveyor, and measured the flow rate near the upper surface of the wire coil and A method was used to measure the flow velocity near the bottom surface. The flow velocity shown in Figure 2 is the average value of the flow velocity on the upper and lower surfaces of the coil, but in the case of side spraying, the difference in flow velocity between the upper and lower surfaces is smaller than in the case of bottom spraying. is noticeable near the edge surface of the wire coil. In the flow velocity pattern shown in FIG. 2, the target position at both edges of the coil is highest, and the velocity decreases toward the center, reaching the minimum at the center. FIG. 3 shows the cooling rate distribution in the width direction of the wire coil, which corresponds to the flow rate distribution in FIG. 2. This result is significantly different from the uniform cooling rate distribution that the inventors had originally expected; the central part of the wire coil is slow, and the fastest cooling rate exists between the central part and the edge of the coil. Although the overall variation in the cooling rate at the same position in the width direction is small, there is a drawback that the cooling rate is not uniform depending on the position in the width direction. The reason for this will be explained with reference to FIGS. 4 and 5. FIG. 4 is a plan view showing a portion of adjacent wire rings when the wire rods are wound into a coil and then transferred by a transfer conveyor in a state where they are shifted at a certain interval and overlapped, and d is a plan view showing a part of the wire rod rings. , D is the distance between the lines, Dmax is the maximum distance between the lines, and L is D>
Indicates a range of 1.5d. Heat transfer when cooling a wire coil by spraying a cooling fluid is mainly controlled by forced convection.
In other words, if the distance D between the wires exceeds a certain value, the cooling rate is determined almost solely by the flow rate of the cooling fluid, and is close to the cooling rate when a single wire is cooled with the same cooling fluid and the same flow rate. It is something. As shown in FIG. 4, the distance D between the wires takes a maximum value (Dmax) at the center in the width direction of the wire coil, and decreases toward the edges. The cooling characteristics at this time can be divided into the following two depending on the distance D between the lines.
First of all, as the line distance D decreases from Dmax, due to mutual radiation heat transfer between adjacent lines,
Although heat dissipation due to radiation from the surface of each wire is reduced, the proportion of this reduction in the overall heat transfer is small. Second, if the distance D between the lines is further reduced, it becomes difficult for the cooling fluid to pass between the lines, and the amount of convective heat transfer is also significantly reduced. According to experiments conducted by the present inventors, the range L shown in FIG. 4, that is, the range where the distance D between the wires is approximately 1.5 times or more the wire diameter d, corresponds to the former (first) cooling feature. Further, when the distance D between the wires is approximately 1.5 times or less than the wire diameter d, the latter (second) cooling characteristic is exhibited. Therefore, in order to obtain a uniform cooling rate distribution in the width direction of the wire coil, it is necessary to provide a flow rate distribution as shown in FIG. That is, when the distance between the lines is approximately D1.5d, the flow velocity distribution is approximately flat and increases slightly toward the edge, and when the distance between the lines is approximately D < 1.5d, the flow velocity distribution is approximately flat toward the edge. It is necessary to provide a flow velocity distribution that increases significantly as the flow rate increases. As mentioned above, when the main line of the cooling fluid in the spray direction on the side surfaces of both edges of the wire coil is sprayed and cooled only at approximately the edges in the width direction of the wire coil, it is particularly difficult to spray the cooling fluid at the center of the coil in the width direction. The flow velocity is slower than in other parts. In order to compensate for this drawback, the main line of the blowing direction of the cooling fluid on the side surfaces of both edges of the wire coil is set so that the width of the wire coil is fixed when the cooling fluid is sprayed and cooled only at approximately the center in the width direction of the wire coil. When we investigated the flow velocity distribution in this direction, we found that it had a slightly medium-height distribution as shown in Figure 6. Combining the distributions in Figures 2 and 6 above, we get
Since the flow velocity distribution is approximately as shown in FIG. 5, the cooling fluid spray flow is the same as the one in which the main line of the cooling fluid blowing direction on the side surfaces of both edges of the wire coil is aimed at approximately the center in the width direction of the wire coil. It has become clear that substantially uniform cooling can be achieved if the coil is cooled by spraying the coil in combination with the cooling fluid sprayed at substantially the edges in the width direction of the coil. Therefore, in the cooling method of the present invention, after the wire rod after hot rolling is wound into a coil shape, the wire rod coil width is From the sides of both edges, on the transfer conveyor,
The purpose of this method is to uniformly cool the wire coil by spraying a cooling fluid by combining a plurality of types of means that provide different flow velocity distributions. In particular, the target position of the main flow of the cooling fluid in the direction of spraying on the side surfaces of both edges of the wire coil is such that the cooling fluid at approximately the center in the width direction of the wire coil is combined with the cooling fluid at approximately the edges in the width direction of the coil. Spraying with water allows for even more uniform cooling. Further, it is preferable that the angle formed between the main line in the direction in which the cooling fluid is sprayed on the side surfaces of both edges of the wire coil and the direction in which the wire coil is transferred is maintained within a range of 15° to 75°. If this angle is less than 15 degrees, the distance between the cooling fluid discharge port and the target position of the fluid becomes too long, and it becomes difficult to obtain a predetermined flow velocity, especially at the central position in the width direction of the wire coil. Furthermore, if the angle exceeds 75°, the fluids sprayed in opposite directions across the width of the wire coil will collide with each other, making it impossible to obtain a stable desired flow velocity distribution, and furthermore, the variation in the flow velocity distribution near the edge of the wire coil will be large. , the cooling rate tends to vary due to deviation in the width direction of the wire coil on the transfer conveyor, and uniform cooling cannot be expected. Therefore, the most effective angle within the above angle range, that is, the angle that allows the most uniform cooling, is in the range of 40° to 50°. Furthermore, the distance from the surface including the wire coil of the cooling fluid discharge port that sprays the cooling fluid aimed at approximately the center in the width direction of the wire coil includes the wire coil of the cooling fluid discharge port that sprays the cooling fluid aimed at approximately the edge in the width direction of the coil. It is preferable to make the distance larger than the distance from the surface. This means that if the distance on the cooling fluid side aiming at the center is made smaller than the distance on the cooling fluid side aiming at the edge, the velocity component of the cooling fluid aiming at the center will change to the middle part between the center and the edge in the width direction of the coil. This is because the flow velocity in the central portion becomes slower than that in the intermediate portion, making it impossible to obtain the desired flow velocity distribution. In addition, regarding the deviation in the width direction of the wire rod coil on the transfer conveyor, the diameter of the wire rod coil changes due to changes in the wire rod speed, winding machine speed, etc. caused by the operating conditions, so the deviation in the width direction of the wire rod coil It is actually difficult to eliminate it completely. That is, as shown in FIG. 10, if the operating conditions are constant, it is possible to aim at the vicinity of the edge of the coil at any time, but as described above, depending on the change in the wire speed, the nozzle 13b can aim at the edge. Sometimes it becomes impossible to aim near the edge. For this purpose, for example, a nozzle that can diffuse the cooling fluid discharged from the nozzle 13b over a certain width may be selected, or, for example, although not shown, the distance from the bias of the coil may be detected in advance with a detector or the like. The nozzle may automatically change its angle freely in response to a signal, so that the entire area near the edge of the wire coil can be cooled at all times. Any of these methods may be used. The basic configuration and desirable aspects of the cooling method of the present invention have been described above, and next, a cooling device for most effectively implementing this method will be described. The cooling device of the present invention is connected to equipment that includes a hot rolling mill, a water cooling device, and a winding machine, and the wire rods sent out in the form of a coil from the winding machine are arranged in overlapping rings shifted at a constant interval. It consists of a transfer conveyor that conveys the wire in groups at a predetermined speed, and a plurality of cooling fluid spray nozzles arranged on both sides of the transfer conveyor along the wire transfer direction.
The cooling fluid spraying nozzle is arranged on both sides of the transfer conveyor over the section where the wire coils need to be cooled, and is connected to an appropriate cooling fluid supply source so as to spray the cooling fluid at a desired flow rate and velocity. are doing. In addition, the above-mentioned spray nozzles are arranged so that the spray direction thereof is at an angle to the transfer direction of the wire coil when viewed from above, so that the cooling fluid sprayed from the nozzles facing each other across the wire coil is constant. They collide at an angle and merge to flow smoothly in the direction in which the wire coil is transported. Moreover, the present invention employs two types of nozzles in which the target position of the spray nozzle with respect to the wire coil (the position where the main flow of the sprayed fluid collides with the coil) is approximately at the center and approximately at the edge in the width direction of the wire coil. They are arranged in combination. An example of a nozzle arrangement is
In order to make the cooling rate uniform, arranging the nozzles aimed at the center and the nozzles aimed at the edges alternately in the direction of movement of the wire coil, and in opposite directions across the coil, are different types of nozzles. Although it is more effective, it is not limited to this, for example, even if a combination of different types is used on the opposing sides, multiple nozzles of the same type are adjacent to each other on the side in which the wire coil advances, and one of the other types is used.
One or more nozzles may be arranged in parallel. Of course, any combination of the above may be used as long as the desired flow velocity pattern can be obtained on the transfer conveyor. Furthermore, the discharge direction of the spray nozzle, which is aimed at approximately the edge, is installed so that the discharge direction is directed downward toward the edge of the coil or horizontally toward the edge. The other spray nozzle aimed at the approximate center is installed above the position of the nozzle aimed at the approximate edge and is directed downward toward the center of the coil, but both the spray nozzles aimed at the approximate edge and the center are at the same height. May be placed.
Further, the position of the ejection opening of the substantially edge-targeting nozzle is installed at a distance from the edge of the wire coil so as not to interfere with deviation in the width direction of the wire coil. In addition, the structure of the cooling fluid spray nozzle itself may be such that the cross section of its discharge port may have any shape such as a slit shape or a circular shape, and each nozzle may be formed individually or all nozzles on one side may be integrated. They may be separated using internal partition plates. Furthermore, the nozzles can be held retractably relative to the wire coil, and all nozzles can be connected to a common fluid supply source, or the edge aiming nozzle and the center aiming nozzle can be connected to separate supply sources. flow rate,
You can also change the flow rate. Next, the present invention will be explained in detail based on embodiment equipment shown in the drawings. FIG. 7 shows a line in which a cooling device 80 according to the invention is arranged downstream of a water-cooled nozzle 1, a pinch roll 2, and a rolling head 3 of a winding machine following a hot rolling mill. That is, directly below the laying head 3 is a wire coil 4 falling continuously in a ring shape.
A conveyor 5 that forms the materials to a desired density and transfers them by placing them.
(Although a roller conveyor is shown in the illustrated example, a chain conveyor may also be used) is provided at a position continuous with the roller conveyor 5 for cooling the wire coil 4 at a predetermined cooling rate while conveying the wire rod 4 at a predetermined rate. A transfer table, for example a roller table 6, is installed. In a certain section (forced cooling section) along the transfer direction of the roller table 6, a plurality of blast nozzles 13 that spray cooling fluid onto the wire coil 4 are arranged in parallel on both sides of the roller table 6. One or more blast nozzles 13 (six in the illustrated example) are provided on both sides of the roller table 6.
A cooling fluid flow path is formed which is connected to the individual collecting ducts 27 and is forcedly fed from the blast blower 12 via the seal duct 28, thereby configuring one cooling zone on the roller table 6. There is. One or more of the cooling zones (six on each side in the illustrated example) constitute one continuous cooling range, whereby the wire coil is cooled along a desired cooling curve while being conveyed. Details of this cooling zone unit are shown in Figures 8 and 9.
As shown in the figure, the blast nozzle 13 has a blast nozzle 13a whose main line of discharge outlet is aimed at approximately the center of the wire coil 4 on the roller table 6, and a blast nozzle 13a whose aimed position is approximately at the edge of the wire coil 4. Blast nozzle 1
It consists of two types of nozzle combination arrangement with 3b. As shown in FIG. 8, these blast nozzles 13a and 13b are arranged differently from each other on one side of the roller table 6 (that is, in the roller table transport direction), and also on the opposite side in the width direction of the roller table 6. They are arranged (staggered) to form a combination of different types. Therefore, the angle α between the main line in the discharge direction of the blast nozzle 13 and the transport direction of the roller table 6 is
The angle is in the range of 15° to 75°, preferably 40° to 50°. In addition, as shown in Fig. 10, the blast nozzle 1
3a and 13b are provided at positions h 1 and h ₂ where the distances from the top of the roller 6a of the roller table 6 of the respective discharge ports are _{h 1 and} h ₂ , respectively. Further, the distance l ₂ from the discharge port of the blast nozzle 13b to the edge end of the wire coil 4 is larger than the distance from the predicted deviation in the width direction of the wire coil 4 on the roller table 6 during cooling. It is arranged so that In addition, a blast nozzle 1 aimed at the center
Distance from the outlet of 3a and the edge of the wire coil 4
l ₁ is l ₁ > 0 in the illustrated example, but if permitted by equipment and operation, l ₁ is set to 0, and the discharge port of the blast nozzle 13a is located closer to the center than the edge end of the wire coil 4. If the coil is placed close to the center of the coil, it becomes easy to generate the desired flow velocity in the center of the coil. In the above embodiment, the blast nozzles 13a and 13b are arranged in the same proportion and the adjacent nozzles are different, but as described above, within the scope of the technical idea of the present invention, Alternatively, adjacent nozzles may be arranged in the same manner. Further, in FIG. 8, the blast nozzles 13a, 13b and the collective duct 27 to which they are connected may have a fixed structure, but may also have a structure in which they are moved away from the roller table 6 by a moving device 81 such as a cylinder. . This is advantageous when you want to secure a work floor, when using the roller table 6 to perform slow cooling, for example by placing a heat insulating cover, and when performing inspection and maintenance of the roller table 6. Because there is. The cooling fluid blown from the blast nozzles 13a and 13b may be selected from air, steam, mist, and a mixture of air and mist, but the same fluid may be supplied to the nozzles 13a and 13b. Alternatively, different types of fluids may be supplied respectively. For example, as a method of spraying cooling fluid, if you aim at the center approximately, you can spray a mixture of air and mist, and if you aim at approximately both edges, you can spray air at the same amount as the amount of cooling fluid aimed at the center. This can be done in small amounts compared to other cases. Next, the operation of the present invention will be explained using cooling of a steel wire as an example. After the hot-rolled steel wire is cooled to a desired temperature by a water-cooled nozzle 1, it is sent to a winding machine by pinch rolls 2, and the rolling head 3 carries it onto the next roller conveyor 5 at a constant speed. The wire rod coils 4 are formed and placed at different intervals and overlapping each other. While the wire coil 4 is being transferred on a roller table 6 by a roller conveyor 5, blast nozzles 1 are arranged on both sides of the roller table 6.
3a and the cooling fluid blown from the blast nozzle 13b, it is cooled along a desired cooling curve to complete the transformation. At this time, the flow velocity distribution in the width direction formed by the blast nozzle 13a and the blast nozzle 13b becomes as shown in FIG. , the average cooling rate distribution during cooling from 800° C. to 400° C. is a substantially flat distribution, as shown by the solid line in FIG. By this cooling, a uniform tensile strength distribution can be obtained as shown in FIG. 1C. Thus, the wire coil 4 cooled to the desired temperature is
Focused by a focusing device. As explained above, according to the method of the present invention, extremely uniform cooling of the wire can be achieved only by spraying the cooling fluid. Examples of the present invention will be described below. This example was tested using the apparatus shown in FIG. 7, and Table 1 shows representative examples of the conditions and results. It should be noted that each steel type in the table had the composition shown in Table 2.

【table】

【table】

[Table] In Table 1, Test Nos. 1 to 4 are the average tensile strengths when cooling is performed using the conventional method, and Tests Nos. 5 to 10 are when cooling is performed using the method of the present invention. It shows the value and the variation σ. In addition, Tests Nos. 1 to 3 above were conducted when the cooling fluid was sprayed only from the bottom surface, and Test No. 4 was based on a cooling method in which the cooling fluid was sprayed from the bottom surface and also from the side as an auxiliary cooling means. be. As is clear from Table 1, for the same steel type and wire diameter, those cooled by the method of the present invention have a remarkable reduction in variation compared to those cooled by the conventional method, especially in test No. 5. , 7, and 10, when the angle between the flow line of the cooling fluid and the transport direction was 45 degrees, the reduction in variation was as much as 40 to 50% in the conventional method. Also, when the wire coil was tested by being biased in the width direction on a transfer conveyor as shown in Test No. 8, the variation was small. As described above, according to the present invention, it is possible to uniformly cool the wire only by spraying the cooling fluid, for example, by mechanically separating the edges of the coil as shown in the prior art. There is no need to use a
Further, cooling can be performed without affecting quality. In addition, it is possible to maintain good cooling even against uneven twisting of the wire coil on the transfer conveyor during operation, and stable operation can be performed, so it has extremely high industrial value.

[Brief explanation of the drawing]

Figure 1A is a graph showing the distribution of the average cooling rate in the width direction of the wire coil between 800°C and 400°C in the conventional method and the method of the present invention; Figure 2 shows the flow velocity distribution of the cooling fluid in the width direction of the wire coil when side spraying is aimed at approximately the edge of the wire coil. Figure 3 is a graph showing the distribution of the average cooling rate in the width direction of the wire coil between 800°C and 400°C when cooling under the conditions shown in Figure 2. Figure 5 is a diagram explaining the cooling characteristics based on the relationship between the distance between adjacent rings of a wire coil and the wire diameter, and Figure 5 shows the flow velocity distribution of the cooling fluid in the width direction of the wire coil when cooling by the method of the present invention. The graph shown in FIG. 6 is a graph showing the flow velocity distribution of the cooling fluid in the width direction of the wire coil when side spraying is aimed at the approximate center of the wire coil, and FIGS.
Fig. 10 shows an embodiment of the cooling device according to the present invention, Fig. 7 is an explanatory diagram of the arrangement of the cooling device in a wire rod rolling line, and Fig. 8 shows details of the cooling zone in Fig. 7. The explanatory drawings, FIGS. 9 and 10, are detailed explanatory views of the arrangement of the blast nozzles in FIG. 7. 1...Water cooling nozzle, 2...Pinch roll, 3...
... Laying head, 4 ... Wire coil, 5 ... Roller conveyor, 6 ... Roller table, 6a ...
Roller, 7a...Base, 12...Blast blower, 1
3, 13a, 13b...Blast nozzle, 27...Collecting duct, 28...Seal duct, 80...Cooling device, 81...Moving device.

Claims (1)

[Claims] 1. After winding the hot-rolled wire into a coil,
When the wire rods are cooled while being transferred by a transfer conveyor in a state where they are shifted at a certain interval and overlapped with each other, the main line in the cooling fluid spraying direction is aimed from the side surfaces of both edges of the wire rod coil to approximately the center in the width direction of the wire rod coil. A method for cooling a hot-rolled wire rod, characterized in that the wire rod is cooled uniformly by spraying a cooling fluid onto the coil so as to substantially form an edge in the width direction of the coil. 2. In a wire cooling device equipped with a conveyor that carries and transports wire rods that have been wound into a coil shape by a winding machine through a hot rolling mill and are overlapped with each other at regular intervals, the wire rods are placed on both sides of the transfer conveyor. A plurality of cooling fluid spray nozzles are arranged in parallel at an angle to the wire coil transfer direction, and the spray nozzles are arranged so that the main discharge line of the nozzle is located at approximately the center portion and approximately the edge portion in the width direction of the wire rod coil. 1. A cooling device for a hot rolled wire rod, characterized in that the cooling device has at least two types of directionality aiming at the above, and is arranged alternately in the transfer direction of the wire rod coil so that opposite sides also have different combinations.