JP2874811B2 - Water cooling method and water cooling device for steel bars and wires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water cooling method and a water cooling apparatus for steel bars and wires, and more particularly to a method for uniformly cooling the steel in the outer peripheral direction. Hereinafter, in the description of the present invention, a wire will be described as a representative example for convenience.

[0002]

2. Description of the Related Art In wire rod rolling, a water cooling device is provided between rolling roll groups to cool a wire rod so as to obtain a desired metallographic structure and mechanical properties.

It is considered that the water cooling can be performed as uniformly as possible. For example, there are the following prior art examples.

[0004] These prior arts should have been the best cooling methods in the era, but with the progress of rolling technology and changes in the quality requirements of customers, they cannot always be said to be sufficient.

That is, the spray swirling nozzle system is disclosed in Japanese Utility Model Publication No. 55-41813 (cooling trough),
No. 45451 (a cooling device for steel rods and wires) belongs to it and has the following difficulties.

Among these cooling methods, Japanese Patent Publication No. Sho 63-4
In No. 5451 (cooling device for steel rods and wires), the upstream unit cools with a high cooling capacity, and the downstream unit performs uniform cooling in the cross-sectional direction by a swirling flow to achieve both high cooling capacity and uniform cooling capacity. However, there is a problem that the temperature unevenness generated on the upstream side is difficult to be eliminated only by the downstream unit.

Although the direct injection nozzle on the upstream side has a high cooling capacity, the uniform cooling capacity is inferior to that of the swirling flow nozzle.

The swirling flow generating nozzle has a double pipe structure, in which a cooling water ejection hole is provided in a tangential direction of the inner wall of the inner pipe of the cooling pipe. Therefore, since the cooling water injected on the inner wall flows along the pipe wall, it is difficult for the cooling water to directly hit the wire at the center of the cooling pipe and to fill the inside of the cooling pipe, so that not only the cooling capacity is low but also the desired cooling capacity. Stable and difficult to obtain.

Further, there has been a problem that the flow velocity of the cooling water injected to the inner wall is attenuated, which impairs the flow below the cooling pipe, inhibits metabolism, and tends to cause uneven cooling of the wire.

[0010] The cooling pipe system with a fin in the pipe is disclosed in
No. 3-19122 (continuous cooling jacket) has the following difficulties.

This method has a double pipe structure, in which a cooling water injection port is composed of an injection hole perpendicular to the traveling direction of the material to be cooled and a hole opened in a tangential direction of the cooling pipe. It is provided with fins for maintenance.

[0012] Therefore, due to the fins provided on the inner wall of the cooling pipe, there is a problem in the material permeability at the rolling speed (maximum 100 m / s), and stable cooling cannot be expected. Further, there are difficulties in terms of workability and cost due to the complexity of the structure.

Further, Japanese Patent Publication No. 63-58207, 63-
No. 58208 and No. 63-58209 (immersion cooling pipes for wire rods and steel bars) do not supply vortex cooling water, and the drain port is not open all the way in the circumferential direction of the circular pipe. The flow rate was difficult to be uniform, and there was a problem with the uniform cooling capacity.

[0014]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional system, and can stably obtain a desired cooling ability. Provided are a water cooling method and a water cooling device for a steel bar or a wire that can stably and uniformly cool an outer peripheral surface in a direction.

[0015]

The gist of the present invention is as follows.

[0016] The first is that a steel bar or a wire rod guided into a water cooling device is disposed in a water cooling pipe peripheral direction from a longitudinal direction of an outer peripheral surface thereof.
The cooling water is swirled through a supply passage that opens continuously in all directions.
The steel bar is fed by being swirled while being turned.
Alternatively, there is provided a water cooling method for a steel bar or a wire rod, which is cooled while directly and continuously colliding with the wire rod.

The second is a water cooling method for a bar or wire rod in which the cooling is performed by multi-stage cooling.

In the third method, a female fitting element 2 having a cooling water supply hole 5 and a fitting chamber 6 is provided at one end of a water cooling tube 4, and a fin 8 which pivots in one direction is provided on one outer periphery. The male fitting element 3 having the hollow guide hole 9 is formed, and the male fitting element 3 is fitted to the female fitting element 2. It is a cooling device.

Reference numeral 4 denotes a water cooling system for bar and wire rods in which the water cooling device 1 constituted by fitting the male fitting element 3 to the female fitting element 2 is installed in multiple stages in a bar / wire guide line.

[0020]

In the water cooling device of the present invention, cooling water is supplied from a cooling water supply hole provided at one end of the water cooling pipe, and the female fitting element provided at the end is fitted with the female fitting element. Is passed through an annular space formed between the male fitting element and the male fitting element, and at this time, the air is swirled by fins provided in one direction on the outer periphery of the male fitting element.

Thereafter, the vortex cooling water is passed through an annular slit formed between an end of the female fitting element on the water cooling tube side and an end of the male fitting element on the water cooling pipe side. The vortex cooling water is jetted from a longitudinal direction of an outer peripheral surface of the vortex cooling water toward a steel bar or a wire rod running through the male fitting element shaft portion in the water cooling pipe, and directly and continuously discharged to the steel bar or the wire rod. Then, it cools while supplying while colliding.

The vortex cooling water supplied by continuous collision is filled in the water cooling tube, and the steel bar or the wire is immersed in the water cooling tube for cooling.

The vortex cooling water supplied by continuous collision is controlled to a predetermined vortex pitch by setting the fin angle θf of the fins 8 to a predetermined angle, so that the cooling water comes into contact with the bar or wire rod and is cooled. I do.

Therefore, in the water cooling apparatus of the present invention, the steel bar or the wire is cooled with a high cooling capacity and uniformly.

Here, the reason for limiting the essential requirements in the configuration of the present invention will be described.

[0026] In the first method, with respect to "steel bar or wire rod, from its outer peripheral surface longitudinally, the entire cooling water pipe circumferential direction
Do not swirl the cooling water through the supply
Supply in the form of a swirl . "

First , in the process of guiding the steel bar or wire into the water cooling device, whether the outer peripheral surface is in the longitudinal direction or not.
Through a supply channel that opens continuously throughout the water cooling pipe circumferential direction.
Cooling water supplied while pivoted Te is going to collide with ejected at vortex state directly and continuously against steel bars or wire. Hereinafter, the cooling water in such a state is continuously
It is called vortex cooling water having a collision point.

It is important that the quality of the steel bars and wires is uniform not only in the cross-sectional direction but also in the longitudinal direction. Therefore, supplying the vortex-shaped cooling water having a continuous collision point in the longitudinal direction of the outer peripheral surface of the bar or wire rod suppresses the variation in the temperature gradient in the cross-sectional direction and the longitudinal direction, and can eventually cool uniformly. This is a necessary condition for uniform quality.

The vortex-shaped cooling water having continuous collision points is completely in contact with the longitudinal direction of the outer peripheral surface of the steel bar or wire introduced into the water cooling device so as to stably obtain a desired cooling capacity. This is a mandatory condition.

In other words, supplying the cooling water in the form of a vortex to cool the longitudinal direction of the outer peripheral surface of the steel bar or wire rod can be seen in the above-mentioned prior art examples. The cooling water is a vortex cooling water having discontinuous collision points.

The vortex cooling water having the discontinuous collision points is hardly filled in the pipe and generates a non-contact portion with the longitudinal direction of the outer peripheral surface of the bar or wire rod. The vortex flow tended to stay in the lower part, and the vortex state was hardly uniform in the cross section direction in the pipe. For this reason, in these prior art examples, the desired cooling ability was not stably obtained, and the uniform cooling property was also inferior.

Therefore, compared to the vortex cooling water having discontinuous collision points in these prior art examples, the vortex cooling water having continuous collision points of the present invention is uniform and uniform in quality. Excellent in terms of.

In the present invention, the vortex-shaped cooling water defined above may be supplied in a direction opposite to the traveling direction of the bar or wire rod or in a direction opposite to the traveling direction. By supplying in the opposite direction, the repulsive kinetic energy with the kinetic energy in the running direction of the steel material can provide a state in which the contact interface in the longitudinal direction of the outer peripheral surface of the steel material with the vortex cooling water under the above conditions is washed. Therefore, it is possible to promote the metabolism of cooling water.

The cooling water exhibiting the vortex state under the above-mentioned limited conditions cools while sufficiently contacting the longitudinal direction of the outer peripheral surface of the bar or wire rod. The contact distance determines the desired cooling capacity of the cooling water. For this reason, in the present invention, the shape condition of the fin of the male fitting element to be fitted into the fitting chamber of the female fitting element is selected and fitted, and the distance in contact with the longitudinal direction is set to a desired distance. Swirling cooling water with impact points
It is a desirable condition for stabilizing to suppress a decrease in the cooling capacity of the cooling water, which is affected by the outer surface contact distance of the wire.

In the second method of the present invention, the multistage cooling under the conditions of the first method is limited. However, this is also the case in the method of the present invention which can stably maintain a high cooling capacity. In some cases, it may not be possible to guide to the next rolling mill by absorbing the processing heat depending on the rolling standard and the rolling speed, or to adjust the temperature gradient in the cross-sectional direction of the bar or wire rod. Indispensable due to the rolling conditions of the wire rod.

The configuration conditions limited by the third device of the present invention are indispensable conditions for the reason limited by the first method. The technology for selecting the fin shape conditions is as follows:
This is effective for simplifying and reducing the cost of the water cooling device, or for selecting and implementing eddy current conditions.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

FIG. 2 is an explanatory view showing an example of a wire rod rolling step in which the water cooling devices 1 according to the present invention are arranged in multiple stages, and a rolling mill 13 reaching a pinch roll 12 in front of a laying head 11.
In between, the water cooling devices 1 are arranged in multiple stages. The conditions for the multi-stage arrangement are determined based on the specifications, dimensions, target quality, and the like of the wire to be rolled, and maintain an appropriate cooling capacity.

From the laying head 11, loose wire 1
4 is condensed by a converging device 16 via a heat treatment device 15 and transported to the next refining process.

The water cooling device 1 according to the present invention shown in FIG. 2 is configured as shown in FIGS. 1 (a) and 1 (b). FIG. 1A is a schematic perspective view showing the structure of the fin 8 of the male fitting element 3 through a part of the female fitting element 2. FIG. 1 (b) is an explanatory view schematically showing the elements of FIG. 1 (a) in partial cross section. The female fitting element 2 is shown in a sectional view and the male fitting element 3 is shown in a schematic view. I have.

In the case of FIGS. 1 (a) and 1 (b),
The female fitting element 2 is provided at the entrance side with respect to the traveling direction of the wire 14.
An example is shown in which the male fitting element 3 is fitted and held.

That is, the water cooling pipe 4 is provided with a female fitting element 2 having a cooling water supply hole 5 and a fitting chamber 6 at one end. On the other hand, the male fitting element 3 is provided with a fin 8 that turns in the same direction on the outer periphery thereof, and a hollow guide hole 9. In the figure, the number of fins is eight, and 7 is an inner wall.

Then, the fins 8 of the male fitting element 3 are inserted into the fitting chamber 6 and fitted with the female fitting element 2 in a state where the cooling water 10 does not leak, thereby forming the water cooling device 1. .

In this configuration, it is the shape condition of the fins 8 that determines the cooling capacity, and FIGS. 1 (a) and 1 (b)
Fig. 2 schematically shows an enlarged view. Here, θf; fin angle θs; slit angle ts; slit width are defined.

The cooling capacity can be adjusted by changing θf, θs, ts and the number of fins.

When the physical properties of the cooling water and the supply conditions are fixed, the water cooling device 1 according to the present invention uses the cooling water shown in FIGS.
(A) An ideal eddy current is generated as in the water model test shown in FIG. 4 (b), and the wire 14 is uniformly cooled.

FIG. 3 shows A of the water model test apparatus 17 shown in FIG.
FIG. 4 (a) is a schematic sectional view taken along the line BB ′ of FIG. 1 (b), and FIG. 4 (b) is a sectional view of FIG.
It is C 'arrow sectional drawing explanatory drawing.

As shown in these figures, the vortex cooling water 10 having continuous collision points is supplied in the longitudinal direction of the outer peripheral surface of the wire rod 14 passing through the water cooling device 1. Then, as shown in FIG. 4A, the vortex cooling water 10 is
Since it is supplied one after another in the longitudinal direction of the outer peripheral surface of the wire 14 and has a continuous collision point, the cooling water 10 is metabolized successively with the cooling water 10 and the required cooling capacity can be maintained. Is done.

For comparison with FIGS. 9 (a) and 9 (b), the cooling device 1 of the applicant company of the present invention was selected from the prior art described above.
8 (Japanese Patent Publication No. 63-45451, cooling system for steel rod and wire)
Fig. 9 (a) and Fig. 9 (b) of the direct injection nozzle
FIG. 5 shows a situation in which a water model testing device 17 shown in FIG.

The swirling flow nozzle of this comparative example uses cooling water 19
9 is supplied from the slit-shaped nozzle 20 in FIG.
The cooling water 19 injected toward the inner wall of the cooling pipe 21 as shown in FIG.
Since the vortex cooling water 19 is supplied along the inner wall 22, it is difficult to fill the inside of the cooling pipe 21, and a non-contact surface is easily generated in the longitudinal direction of the outer peripheral surface of the wire 14.

Therefore, it is difficult for the cooling water 19 to obtain a desired cooling capacity, and it is difficult to perform stable and uniform cooling. In other words, in the comparative example, since the collision point has a discontinuous vortex shape, cooling in the longitudinal direction of the outer peripheral surface of the wire 14 is uneven, and the wire 14
Easy to affect the quality of the product.

The direct injection nozzle shown in FIG. 9B has a high cooling capacity by the cooling water 19, but is inferior to the swirling flow nozzle in the uniform cooling capacity.

On the other hand, the cooling method according to the present invention is shown in FIG.
As described above, the present invention is characterized in that cooling can be performed by directly jetting the vortex-shaped cooling water 10 having collision points continuous in the longitudinal direction of the outer peripheral surface of the wire rod 14.

FIG. 5 shows a water model test apparatus 17 in which the system of the present invention is tried. The guide roller 24, the electric furnace 25, and the guide roller 2 are placed on a gantry 23 in this order from the entrance side of the wire rod 14.
6. Draining nozzle 27 provided via a compressed air device not shown and pipe, water cooling device 1 provided via cooling water supply device not shown and flow meter 28, pressure gauge 29, guide roller 3
0, a draining nozzle 31 provided via a compressed air device (not shown) and a pipe, a pinch roller 34 provided rotatably via a driving device 32 and a belt 33, an upper thermoviewer 35,
The lower thermoviewer 36, the guide rail 37, and the waterproof cover 38 surrounding the guide roller 26 to the drainer nozzle 31 are tested by using the sample wire rod 14.

Using this water model test apparatus 17, a characteristic study on cooling of the water cooling apparatus 1 according to the present invention was conducted. As a result, the results shown in FIGS. 6 to 8 were obtained, and based on the results, the shape conditions of the fin 8 were investigated. Table 1 shows the physical conditions of the cooling water 10 used in this test.

[0056]

[Table 1]

FIG. 6 shows the result of examining the fin angle θf. It can be seen that the vortex pitch depends on the fin angle.
Here, the vortex pitch refers to the length of the pitch of one cycle of the vortex in the water cooling tube measured with a high-speed video camera with the tracer 39 inserted.

In FIG. 6, the □-□ line indicates a cooling water flow rate of 300.
Liter / min, and the 〇-〇 line is 400
The case of liter / min is shown.

The water cooling apparatus 1 of the present invention was configured in such a manner as to obtain the optimum conditions. As a result, as shown in the graph of FIG. 7, the temperature unevenness could be reduced. That is, the dotted line in FIG. 7 indicates the level at the time of cooling of the wire sample as a test material, and the method according to the present invention suppresses temperature unevenness at the time of cooling of the wire sample as indicated by the 〇-〇 line. Recognize.

In FIG. 7, the □-□ line shows a trial of the swirling flow nozzle of Japanese Patent Publication No. 63-45451 (Nippon Steel) among the above-mentioned prior art cases, and the dimensional conditions are shown in Table 2. .

[0061]

[Table 2]

As is apparent from FIG. 7, in the method in which the swirling flow nozzle is provided, temperature unevenness occurs.

Further, in FIG. 7, the line △-△ is a Japanese Patent Publication No. 63-45451 (Nippon Steel) among the prior art examples described above.
Table 3 shows the dimensional conditions.

As is clear from FIG. 7, in the method in which the direct injection nozzle is provided, temperature unevenness occurs.

[0065]

[Table 3]

Further, as a result of examining the cooling capacity of the cooling device of the present invention, as shown in the graph of FIG.
It turned out that it has high cooling capacity at the same cooling water flow rate. That is, in FIG. 8, the 〇-〇 line shows the heat transfer coefficient representing the cooling capacity of the present invention, and the □-□ line shows the direct injection nozzle of Japanese Patent Publication No. 63-45451 (Nippon Steel) of the above-mentioned prior art case. The Δ- △ line shows the cooling capacity of the swirl flow nozzle in the same manner, and it can be seen that the method according to the present invention has a higher cooling capacity than other cooling devices.

[0067]

As described below, the present invention exerts industrially beneficial effects in addition to the above-mentioned initial objective technical problems.

According to the present invention, a high cooling capacity can be obtained.

According to the present invention, a high cooling capacity can be stably obtained.

According to the present invention, since stable and uniform cooling can be performed, it is possible to improve the quality of steel bars and wires.

In the present invention, since the main structure of the water cooling device 1 is a structure in which the male fitting element 3 provided with the fins 8 is fitted to the female fitting element 2 of the water cooling tube 4, for example, the male fitting Element 3
The shape conditions of the fins 8 can be selected by the selective fitting of the fins 8, so that the cooling conditions can be configured and maintained in accordance with the type of the steel bar / wire and the desired quality requirements.

In particular, such a male fitting element 3 and a female fitting element 2
Is a unique effect not found in the above-mentioned prior art examples, and is industrially useful in rolling bar and wire rods.

[Brief description of the drawings]

1 (a) is a schematic perspective view showing a water cooling device according to the present invention in a partially perspective view, and FIG. 1 (b) is FIG. 1 (b).
3 is an explanatory diagram schematically showing a partial cross section of the element.

FIG. 2 is an explanatory view showing an example of a wire rod rolling step in which water cooling devices according to the present invention are arranged in multiple stages.

FIG. 3 is a partial cross-sectional view of the water cooling device according to the present invention shown in FIG.

4 (a) is a schematic sectional view taken along the line BB 'of FIG. 1 (b), and FIG. 4 (b) is a sectional explanatory view taken along the line CC' of FIG. 3; is there.

FIG. 5 is a schematic diagram of a water cooling device.

FIG. 6 is a graph showing a result of a shape characteristic test of a fin according to the present invention.

FIG. 7 is a graph showing a relationship between temperature variation and cooling water flow rate.

FIG. 8 is a graph showing a relationship between a heat transfer coefficient and a flow rate of cooling water.

FIG. 9 (a) is an explanatory diagram of a cooling water flow of a swirling flow nozzle in a conventional example, and FIG. 9 (b) is an explanatory diagram of a cooling water flow of a direct injection nozzle in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water cooling device 2 Female fitting element 3 Male fitting element 4 Water cooling pipe 5 Cooling water supply hole 6 Fitting chamber 7 Inner wall 8 Fin 9 Guide hole 10 Cooling water 11 Raying head 12 Pinch roll 13 Rolling machine 14 Wire rod 15 Heat treatment device Reference Signs List 16 focusing device 17 water model testing device 18 water cooling device 19 cooling water 20 slit-shaped nozzle 21 cooling pipe 22 inner wall 23 gantry 24 guide roller 25 electric furnace 26 guide roller 27 drain nozzle 28 flow meter 29 pressure gauge 30 guide roller 31 drain Nozzle 32 Drive unit 33 Belt 34 Pinch roller 35 Upper thermoviewer 36 Lower thermoviewer 37 Guide rail 38 Waterproof cover 39 Tracer θf Fin angle θs Slit angle ts Slit width

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-B 63-45451 (JP, B2) JP-B 53-19122 (JP, Y2) JP-B 55-41813 (JP, Y2) (58) Field (Int.Cl. ⁶ , DB name) B21B 45/02 C21D 9/573

Claims (4)

(57) [Claims] 1. A steel bar or a wire rod guided into a water cooling device is entirely extended from a longitudinal direction of an outer peripheral surface to a water cooling tube circumferential direction.
Do not swirl the cooling water through the supply
The steel bar or wire is supplied in a spiral form
A water cooling method for a steel bar or a wire rod, wherein cooling is performed while directly and continuously colliding with the rod. 2. The method according to claim 1, wherein the cooling is performed by multi-stage cooling. 3. A cooling water supply hole 5 is provided at one end of the water cooling pipe 4.
And a female fitting element 2 having a fitting chamber 6 and a fin 8 pivoting in one direction on the outer periphery, and a male fitting element 3 having a hollow guiding hole 9 formed therein. A water cooling device for steel bars and wires, wherein the fitting element 3 is fitted to the female fitting element 2. 4. The water cooling device for bar and wire rods according to claim 3, wherein the water cooling device 1 configured by fitting the male fitting element 3 to the female fitting element 2 is installed in multiple stages on the guide line for the bar and wire rods. .