JP3626554B2 - Coil box mandrel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mandrel for a coil box.
[0002]
[Prior art]
In recent years, in a hot rolling facility, a coil box provided with a winding and unwinding machine is provided between a rough rolling mill and a finish rolling mill, and the material to be rolled is wound on a cradle roll, and then the coil is rolled. There has been proposed a rolling method for rewinding and feeding to a finishing mill (Japanese Patent Laid-Open No. 7-275934).
[0003]
In the method, since the material to be rolled is once wound into a coil shape, the temperature reduction of the material to be rolled is small, but the mandrel of the coil box has a water cooling structure, and the inner peripheral surface of the coil is By being naturally cooled in contact with the atmosphere from winding to rewinding, the temperature drop is larger than other parts. Therefore, there is a problem that a defective portion is generated in the tail portion of the finished rolled material and the yield is poor.
Therefore, JP-A-8-24947 proposes a method of preventing a temperature drop by heating a mandrel with a mandrel heating device and heating the tail portion of the rough rolling coil with the stored heat.
[0004]
[Problems to be solved by the invention]
However, the method disclosed in JP-A-8-24947 requires a mandrel heating device separately from the mandrel, which not only increases the equipment itself, but also reduces the temperature of the mandrel itself from winding to unwinding. Inevitably, as a result, the temperature of the inner peripheral surface of the coil also drops, and it is difficult to perform good finish rolling.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a mandrel of a coil box that can reliably prevent a temperature drop at the inner peripheral portion of a rough rolled coil with a simple configuration.
[0006]
[Means for Solving the Problems]
To achieve the above object, the mandrel of the present invention, in the mandrel of the coil box sending the mill finish rewound with the rough rolled rolled material wound into a coil, the mandrel together with the water-cooling structure, the outer periphery thereof A plurality of annular recesses are formed on the surface, a heat insulating material is attached in the recesses, and a burner nozzle is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the mandrel 1 of the coil box of the present invention is provided with a flame forming portion 3 that forms a combustion flame F at the tip of a mandrel body 2. As shown in FIG. 2, the mandrel body 2 is positioned with a required interval S between its outer peripheral surface and the inner peripheral surface of a coil C formed by winding the material that has been roughly rolled. It has a substantially cylindrical shape.
[0008]
A cooling water passage 4 including a cooling water supply passage 4a and a cooling water drainage passage 4b is provided in the central portion of the mandrel body 2 so that the mandrel 1 has a water cooling structure.
A plurality of fuel gas supply passages 5 are provided outside the cooling water passage 4, and these gas supply passages 5 communicate with a plurality of annular communication passages 6 provided at the tip of the mandrel body 2. ing. Each communication passage 6 is provided with a plurality of burner nozzles 7 opened outward from the mandrel body 2 at equal intervals, and the burner nozzles 7 constitute the flame forming section 3.
[0009]
As shown in FIGS. 1 and 3 , the burner nozzle 7 is provided with a plurality of annular recesses 8 in the mandrel body 2 at predetermined intervals, and the surface of the recesses 8 is made of heat-resistant steel while maintaining a prescribed distance α. the heat insulating material 9 with the cover member 10 such that not loaded, attach the burner nozzle component 12 into the hole 11 bored in the heat insulating material 9 and the cover member 10.
[0010]
In this way, the cooling action by the water-cooled mandrel body 2 can be reduced, and even if the coil C contacts the mandrel 1 during winding and unwinding operations of the coil C, the presence of the distance α It is possible to prevent the burner nozzle 7 from being blocked and the burner nozzle constituent member 12 from being damaged.
[0011]
The mandrel main body 2 having the above-described configuration can be driven to rotate on a mandrel support (not shown) as in the above-mentioned Japanese Patent Application Laid-Open Nos. 7-275934 and 8-24947, and in some cases, can move forward and backward with respect to the coil C. It is attached to a support base or a support base that can rotate and swing. The cooling water passage 4 and the gas supply passage 5 are connected to a water supply facility, a drainage facility, and a gas supply facility via a rotary joint 13 attached to the rear end portion of the mandrel main body 2, respectively.
[0012]
Therefore, when forming the coil C made of the material to be rolled roughly rolled by the coil box including the mandrel 1, for example, the flame forming portion 3 at the tip of the mandrel 1 is placed on a cradle roll (not shown). And positioned at the center of the coil C to be formed. In this state, winding of the material to be rolled is started by the cradle roll, and the fuel gas injected from each burner nozzle 7 is ignited by an ignition torch (not shown) or the like, thereby heating the inner peripheral surface of the coil C. Note that a premix gas or a raw gas is used as the fuel gas.
[0013]
As a result, the inner peripheral surface of the coil C is heated by the opaque portion at the tip of the combustion flame F where the temperature is high, and the temperature drop of the tail portion (about 2 to 3 m) of the rolled material of the coil C is surely prevented. To do. In addition, the combustion flame F positioned on both ends of the coil C prevents thermal radiation from being radiated from the inner peripheral surface of the coil C to the outside of the coil C at the opaque portion, thereby improving thermal efficiency.
[0014]
When the material to be rolled is finished to be coiled, the coil-shaped material to be rolled is rewound and sent to a finishing mill to perform finish rolling. During the rewinding, the mandrel 1 prevents the coil C from being pulled out of the cradle roll by being pulled by the finishing mill.
[0015]
The mandrel of the present invention is not limited to the above-described configuration. For example, as shown in FIG. 4, each of the mandrels corresponds to each burner nozzle 7 provided at a predetermined interval in the circumferential direction without providing the communication passage 6. The gas supply path 5 may be formed, and the burner nozzle 7 may be provided in the mandrel body 2 without using the heat insulating material 9 or the like.
[0016]
【The invention's effect】
As is apparent from the above description, in the mandrel of the coil box of the present invention, as described in JP-A-8-24947, the mandrel is preheated by a mandrel heating device different from the mandrel, and the stored heat is used to coil the mandrel. This is not a large-scale facility that prevents the temperature drop of the coil, but a simple configuration in which a burner nozzle is provided on the outer peripheral surface of the mandrel. Therefore, satisfactory finish rolling can be performed in the subsequent process, and the yield of products can be improved.
[0017]
Moreover, since forming the heat insulating material in which is provided in an annular recess formed in the mandrel body to burner nozzles, reduce water cooling effect on the heating zone of the mandrel, it can be improved correspondingly heating efficiency.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a mandrel and a coil according to the present invention.
2 is an enlarged sectional view taken along line II-II in FIG.
FIG. 3 is a partially enlarged view of FIG. 1;
FIG. 4 is a cross-sectional view showing a modification of the mandrel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Mandrel, 2 ... Mandrel main body, 3 ... Flame formation part, 4 ... Cooling water passage, 5 ... Fuel gas supply path, 7 ... Burner nozzle, 8 ... Annular recessed part, 9 ... Thermal insulation, C ... Coil, F ... Combustion flame .

Claims (1)

In the mandrel of the coil box, the rolled material that has been roughly rolled is wound into a coil and rewinded and sent to a finishing mill.
With a water-cooling structure the mandrel to form a plurality of annular recesses on its outer peripheral surface, the mandrel of a coil box, characterized in that a burner nozzle is attached insulation in this recess.

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