JPS59166317A - Water cooling method of wire rod in wire rod rolling - Google Patents

Abstract

PURPOSE:To cool a wire rod uniformly and to improve its descaling property by detecting introduction of the wire rod on outlet side in the cooling zone of the wire rod and preventing contact between the wire rod and a water cooling pipe by raising rollers provided in front and rear of the water cooling pipe. CONSTITUTION:A rolled wire rod 13 is passed through a water cooling pipe 11 and a hydroextracting pipe 18 in the water cooling zone 2 and taken up on a winder 3. Introduction of the wire rod is detected by a wire rod detector on outlet side of the water cooling zone 2, and rollers 15 provided in front and rear of the water cooling pipe 11 are raised by a controller to prevent contact between the wire rod 13 and water cooling pipe 11. As the wire rod 13 is cooled uniformly over whole periphery and the surface condition is made uniform, descaling property can be uniformed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to water cooling of a wire rod after rolling in wire rod rolling.

As shown in FIG. 1, in the rolling of wire rods, a water cooling zone 2 consisting of multiple rows of water cooling pipes 11 and drain pipes 18 is installed between the final rolling mill 1 and the winding machine 3 for forced or natural air cooling. The coiling temperature measured by the thermometer 4 should be controlled within a certain range (feedback control is performed).

That is, data from the thermometer 4 is input to the temperature indicating controller 5, which sends a signal to the flow rate indicating controller 6 to control the regulating valve 7.

In FIG. 9, 9 is a cooling water pipe, 8 is a flow meter placed in front of the control valve 7, and its data is sent to the flow rate indicating controller 6. This makes the mechanical properties of the product uniform and improves descaling properties during secondary processing, so uniform winding temperature is very important in terms of product quality. In the feedback control shown in FIG. 1, the winding temperature in the longitudinal direction of the wire is kept within the tolerance T with respect to the target temperature Ts.

That is, it is possible to control within Ts±ΔT.

However, this is the result of temperature measurement being performed only from one direction with respect to the circumferential direction of the wire cross section, and in reality, there is non-uniform cooling in the circumferential direction, so it is sufficient that the temperature is not within ΔT. could be. In other words.

The shape of the water cooling pipe 11 is as shown in Fig. 2, and there is a gap between the open pipe lla and the closed pipe llb, and water 12 flows through the pipe from the circumferential direction of the pipe. It is commonly used and is designed to be dispensed evenly. Also, drain pipe 1 installed downstream
8 is a generally used one with an opening in the direction in which the wire enters. When the wire passes through the pipe, the third
As shown in the cross section of the figure, the wire rod 13 contacts the lower part of the pipe, and the water flows downward along the circumferential direction of the pipe, so the lower part of the wire rod 13 is sufficiently cooled, but the upper part is not cooled very much. . 4 The relationship between the circumferential angle of the wire cross section and the coiling temperature Ts after cooling is shown in FIG. 4. It is sufficient if the difference between the maximum value Tu and the minimum value Td at this time is within 2ΔT, but in reality this often exceeds 2ΔT (which is a cause of large variations in quality).

The present invention was made in consideration of the actual situation of dipping, and its gist is that a wire rod detector is installed on the outlet side of a water cooling zone 2 for wire rods, which consists of five water cooling pipes 11 and drain pipes 18 arranged in a row in the direction of travel. In response to a signal from It is possible to position it in the center of the tube 11, thereby eliminating differences in cooling in the circumferential direction of the cross section of the wire rod, thereby making it possible to produce wire rod products of uniform quality.

This will be explained in detail below based on the drawings.

In the present invention, as shown in FIG. 5, centering rollers 15 attached to the front and rear of the water-cooled pipe 11 lift the water-cooled pipe 11 so that it is perfectly centered within the pipe. This prevents the lower part of the wire rod 1213 from being excessively cooled even when the cooling water uniformly blown out from the circumferential direction of the pipe through the small gap 14 flows through the lower part of the pipe, and the degree of cooling is reduced by the amount of water. Uniform cooling can be achieved in one circumferential direction. Furthermore, since the cooling water passes through the pipe and is sprayed onto the centering roller 15 before being drained, there is an advantage that the centering roller is cooled by this cooling water.

Next, the timing for raising the centering roller 15 is controlled by a wire detector 16 installed immediately after the water cooling zone 2 (if a wire detector is installed on the entry side, a timer for delaying the wire must be used. Based on the detection signal, the roller 15 rises and blocks the entrance of the water-cooled pipe 11, and then the wire 13 enters, which causes a problem that the wire 13 cannot enter the water-cooled pipe 11).

That is, as shown in FIG. 6, when the wire 13 leaves the water cooling zone 2, the wire detector 16 is turned on and sends a signal to the roller operation control section 17. Upon receiving the signal, the control unit 17 issues a command to raise the centering roller 15, and when the wire detector 16 turns OFF and stops sensing the wire 13 after the tail end of the wire 13 has passed, the centering roller 15 is activated in the opposite direction. Lower the roller 15. Until the wire detector 16 is turned on, the wire 13 is in contact with the lower surface of the pipe in the water cooling zone 2, which causes non-uniform cooling in the circumferential direction as before, but its length is Compared to this, the amount is small, and the advantage of uniformly cooling the remaining portion is sufficiently large.

The wire diameter is set in the control section 17 so that the amount of rise of the roller 15 can be changed according to the diameter of the wire 13.

The control unit 17 determines the amount of rise of the roller 15 according to the set wire diameter. This ensures that the wire is always located at the center of the pipe.

Non-uniformity due to positional bias will no longer occur.

When the wire was cooled using the apparatus of the present invention, very good results were obtained. First, regarding the uneven part at the tip, when a normal HMD was used as a wire detector, the distance from the water cooling zone entrance to the HMD detection point was about 12 m, and the line speed was about 40 m/s, so it was about 0.
．． There is a delay of 3 seconds, and since it takes about 0.5 seconds for the HMD to turn on, transmit the signal, and raise the centering roller to the specified position, the
Although cooling was non-uniform with respect to m, the non-uniformity of the degree of cooling in the circumferential direction was extremely improved in the subsequent portions. That is, for a product with a target winding temperature of 880° C., the temperature in the circumferential direction at a 10 m point and a portion past 32 m from the tip is shown in a graph as shown in FIG.

The error of 120°C from the target temperature is less than ±10°C. Furthermore, in the conventional method, since the wire was in contact with the bottom surface of the pipe in the length direction, the amount and time of contact with the water flowing toward the drain pipe varied, resulting in uneven cooling. Including non-uniformity, the limit of control was about ±30°C relative to the target value, but with the method of the present invention, as shown in Figure 5, there is no contact with the water flowing toward the drain pipe, so it can be controlled for a long time. Non-uniformity in cooling in the transverse direction has almost disappeared, and it has become possible to control the winding temperature within approximately ±10°C.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of water cooling control, Figure 2 is an explanatory diagram of a conventional water cooling pipe, Figure 3 is a sectional view showing the relationship between the water cooling pipe and wire in the conventional method, and Figure 4 is the conventional water cooling method. Figures 5a and 5b are diagrams showing the temperature distribution in the circumferential direction of the wire, Figures 5a and 5b are explanatory diagrams and cross-sectional views of the water cooling system according to the present invention, Figure 6 is a schematic diagram of its control, and Figure 7 is a diagram showing the effects of the present invention. This is a graph of the ratio shown. 11...Water cooling pipe, 18...Water drain pipe. 2...Water cooling zone, 16... Line detector. 13...Wire rod, 15...Loranzo 4'A for centering, 31W, yg-5a, dedicated to

Claims (1)

[Claims] A large number of water cooling pipes (11) and drain pipes (
9 individual water-cooled pipes (1
When detecting the wire, raise the rollers (15) provided before and after the wire rod. A water cooling method for a wire rod, characterized in that the wire rod can be positioned at the center of the water cooling tube (11) while ensuring that the wire rod enters the water cooling tube (11) by lowering the wire rod when the wire rod is not detected.