JPS62120433A - Roll for cooling strip - Google Patents

Abstract

PURPOSE:To stabilize the quality of a strip wound around a cooling roll and cooled by feeding a refrigerant to the inside of the roll by arranging many polygonal projections on the whole peripheral surface of the roll at regular intervals so as to reduce a temp. difference in the roll. CONSTITUTION:Many projections 11 are arranged on the whole peripheral surface of a cooling roll 10 so that the tops of the projections 11 from a cylindrical roll surface as a whole. The projections 11 may by hexagonal blocks and are attached to the roll 10 with bolts 12 through packing 13. The projections 11 are arranged at regular intervals (d) of width S. A refrigerant W is fed to the inside of the resulting cooling roll 10 to cool a strip wound around the roll.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a cooling roll used as a means for cooling a strip such as a thin steel strip when the strip is subjected to heat treatment such as annealing.

<Prior art> Gas jet cooling is used as a means of cooling hot steel strips in heat treatment lines such as continuous annealing equipment.

A wide variety of methods have been adopted, such as hot water cooling, air-water cooling, and roll cooling, but among these, the roll cooling method is particularly efficient in terms of cooling speed.

A conventional roll cooling device used in a cooling zone of continuous annealing equipment will be explained based on FIGS. 12 to 14. This device has several cooling rolls 1, and is used to cool a filtered steel strip (referred to as an IJ roll) 9 that is wound around the cooling rolls 1 and passed through. The cooling roll 1 is hollow, and water W as a refrigerant is passed through the cooling roll 1 to cool the strip 9 in contact with the circumferential surface of the cooling roll 1. A gas jet device 2 is provided near the cooling roll 1, and blows a gas jet from the back side of the strip 9 to press the strip 9 against the cooling roll 1 to improve cooling efficiency. In addition, the water surface position inside the cooling roll 1 is set slightly above the axis of the cooling roll 1, so that the rotation of the cooling roll I stirs the water inside and improves the cooling efficiency. There is.

<Problems to be Solved by the Invention> The slip 1-lip 9 does not always contact the entire circumferential surface of the cooling roll 1, but the area of the circumferential surface of the cooling roll 1 sequentially contacts the strip, and As shown in FIG. 15, the central part of the cooling roll 1 in the axial direction becomes a heating part that comes into contact with the high temperature strip 9, and the both ends thereof
This is a non-heating part that does not come into contact with the

In this way, the strip 9 is formed in the circumferential axial direction of the cooling roll 1.
The following problems have arisen because a heating section that is heated and a non-heating section that is not heated are formed.

That is, the heated part of the cooling roll 1 that is in contact with the strip 9 has a temperature distribution in the radial direction of the roll as shown in FIG. 15, but the temperature is different from that of the non-heated part. This gives rise to the following problem.

■ The average temperature of the cooling roll cylinder in the non-heating section can be considered to be approximately the water temperature (T,);
) and the average temperature (T, ) of the cooling roll body in the heating section (%, > T, ) is large, so the cooling roll 1 has a heat crown (δ) as shown in FIG.
will occur. As a result, a gap is created between the circumferential surface of the cooling roll 1 and the side edge of the slip slip 9, causing temperature unevenness in the strip 9, resulting in a decrease in quality and poor product yield.

■ Since the temperature difference (T3>T2) between the body surface temperature (r3) and the body inner surface temperature (T2) of the cooling roll in the heating section is large, the temperature of the cooling roll 1 increases due to the bimetallic effect as shown in Fig. 17. Local bending deformation (δ2) occurs in the trunk. For this reason, as in the case (2) above, temperature unevenness occurs in the strip 9, resulting in poor product yield.

(2) Since the temperature difference between the body surface temperature (T3) and the body inner surface temperature (T2) of the cooling roll in the heating section is large, compressive stress is generated on the body surface of the cooling roll 1. As a result, yielding, cracking, etc. occur on the circumferential surface of the cooling roll 1, resulting in a shortened lifespan.

The present invention was made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a cooling roll that rationally solves the above-mentioned problems.

Means for Solving the Problems> The cooling roll for a strip according to the present invention cools the strip wrapped around the circumferential surface by passing a refrigerant through the inside of the cooling roll. It is characterized by having a large number of polygonal protrusions arranged with gaps between them.

Due to the presence of protrusions between the high-temperature strip and the circumferential surface of the cooling roll, the temperature difference between the heated and non-heated parts of the cooling roll and the temperature between the surface and inner surface of the cooling roll are reduced. The difference becomes smaller and thermal deformation of the cooling roll is prevented. At this time, the thermal expansion of the protrusion will be absorbed by the gap.

Embodiment An embodiment of the present invention applied to the roll cooling device described above will be described based on the drawings.

1 to 3 are drawings showing one embodiment of the present invention.

As shown in the figure, the cooling roll 10 of this embodiment is provided with a large number of protrusions 11 over its entire circumferential surface (body surface), and the end surface of these protrusions 11 presents a circumferential roll surface as a whole. There is. The thickness of this cooling roll 10 is set to be thinner than that of the conventional cooling roll 1 by the height h of the projections 11.

Each of the projections 11 is a polygonal (hexagonal in this embodiment) block, and is attached to the cooling roll 10 with bolts 12. 13 Furthermore, the protrusion 11 is arranged with a gap d of radius S between it and other protrusions 11 adjacent to each other, and the tip corner lie of the protrusion 11 is chamfered as shown in detail in FIG. This is done to prevent damage to the strip 9 being wound.

The effect of the cooling roll 100 having the above configuration is similar to that of the conventional cooling roll 1.
This will be explained in comparison with. Cooling roll 1 according to the present invention
0 heating section and the heating section of the conventional cooling roll 1, the fourth
As shown in the figure, a difference occurs in the temperature distribution. That is, in this embodiment, compared to the conventional method, the average temperature of the cooling roll's body, which is a cause of heat crown, is reduced from - to T', and the temperature of the body surface of the cooling roll, which is a cause of bending deformation and surface stress, is reduced from - to T'. The temperature has decreased from T3 to T'.

(7) As a result, the amount of crown (heat) and crown, which was conventionally δ, Lx, R(T, -T,), is
On the body side, δ,′(X:R(T,,′ −T,), and on the protrusion 11 side, δ□′och(T,,−T,l, and the total is (δ,′10,′ ], that is, R>>h
(Here, R is the diameter of the cooling roll 10, and h is the height of the protrusion 11.) Therefore, it can be regarded as δ, ′) δ, ′.
(T, -11>(T,'-T), and the P1-crown amount of this embodiment is smaller than the conventional heat crown amount δ1.

Further, in this embodiment, the amount of bending deformation, which was conventionally δ2oC(T, -T2), is δ2' on the body side of the cooling roll 10.
oc (T3' - T2), δ2'' o on the protrusion 11 side
c (T, -T,,'). However, since the amount of deformation δ' of the protrusion 11 is absorbed by the gap d, it can be regarded as almost zero. T,,'-''['21
Therefore, in this embodiment, the amount of bending deformation is small.

In addition, the surface stress that was conventionally σoc (T, -T2) is changed to σ' (T3) on the body side of the cooling roll 10 in this embodiment.
'-T2), and on the protrusion 11 side, it becomes (T, -T,'). That is, (T:, -T2) >(T,'-T
, )X(L-T3'), the surface stress of this embodiment is smaller than that of the conventional one.

FIGS. 5 to 8 are drawings showing another embodiment of the present invention. In the above embodiment, the same parts are given the same reference numerals and only the different parts will be explained.

As shown in the figure, the cooling roll 10 of this embodiment is attached by fitting blocks forming square projections 11 into grooves 15 provided on the circumferential surface of the roll 10. A large number of grooves 15 are formed in the axial direction of the cooling wheel 10, and the grooves 15 are
1 block is 1g15 from one end of the cooling roll 10
A large number of them are attached with a gap d between them by fitting them together and sliding them one after another toward the other end. A presser block lfa is welded to the end of the cooling roll 10, and the protrusion 11 fitted in the groove 15 is fixed by the presser block lla.

In the cooling roll 10 of this embodiment, heat crown, bending deformation, and surface stress can be reduced to such an extent that they can be practically ignored, as in the above embodiments.

FIGS. 9 to 11 are drawings showing still another embodiment of the present invention. Incidentally, the same parts as those in the previous embodiment are given the same reference numerals, and only the different parts will be explained.

As shown in the figure, the cooling roll 10 of this embodiment has a relatively large number of protrusions 11 formed by forming a large number of grooves 16 on the surface of the body. Therefore, the cooling roll 10
The size, shape, etc. of the protrusion 11 are determined by the manner in which the grooves 16 extend in the axial direction and the circumferential direction and intersect with each other. 1416 has a width S, and these grooves 16 themselves are provided between the protrusions 11 to form a gap d. In addition, the bottom part 16a of the slag 16 prevents stress in the ditch.
It has been processed to give it a rounded shape.

In the cooling roll 10 of this embodiment, heat crown, bending deformation, and surface stress can be reduced to such an extent that they can be practically ignored, as in the previous embodiment.

<Effects of the Invention> According to the present invention, it is possible to reduce the temperature difference occurring in the cooling roll, and to reduce beat crown and bending deformation to a practically negligible extent, thereby realizing stabilization of strip quality and improvement of yield. At the same time, the life of the cooling roll can be extended by reducing the surface stress to a practically negligible level.

[Brief explanation of drawings]

1 to 3 relate to one embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view showing a part of the cooling roll, FIG. 2 is a plan view showing a part of the circumferential surface of the cooling roll, and FIG. Fig. 3 is an enlarged view of part A in Fig. 1, Fig. 4 is a temperature distribution diagram illustrating the effect of the present invention in comparison with the conventional one, and Figs. 5 to 8 are other embodiments of the present invention. 5 is a vertical sectional view showing a part of the cooling roll, FIG. 6 is a cross sectional view showing a part of the cooling roll, FIG. 7 is a perspective view of the protrusion, and FIG. Enlarged view of part B, No. 9
9 to 11 relate to still another embodiment of the present invention, and FIG.
The figure is a vertical sectional view showing a part of the cooling roll, Fig. 10 is a cross-sectional view showing a part of the cooling roll, Fig. 11 is an enlarged view of the section ('' in Fig. 10, and Fig. 12 is a conventional A perspective view of a roll cooling device, FIG. 13 is a longitudinal sectional view of a conventional cooling roll, and FIG. 14 is a perspective view of a roll cooling device.
The figure is a cross-sectional view of a conventional cooling roll, FIG. 15 is a temperature distribution diagram of the cooling roll, and FIGS. 16 and 17 are conceptual diagrams explaining conventional failures. In the drawings, 9 is a strip, 10 is a cooling roll, 11 is a protrusion, and d is W. Patent applicant: Mitsubishi Heavy Industries, Ltd., acting agent

Claims (1)

[Claims] A cooling roll for cooling a strip wrapped around the circumferential surface by passing a refrigerant through the inside, characterized in that a large number of polygonal protrusions arranged with gaps between each other are provided over the entire circumferential surface. roll.