JP3767762B2 - Roll cooling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a roll cooling device that cools the surface of a rolling roll of a hot rolling mill.
[0002]
[Prior art]
In the case of hot rolling, the rolling material itself is at a high temperature, but in addition to this, processing heat generated by plastic deformation of the rolling material, frictional heat between the rolling material and the rolling roll, etc. are generated, so the rolling roll is heated. . This heating causes thermal expansion in the heating section of the rolling roll, resulting in a convex heat crown, resulting in uneven thickness of the rolled material. For this reason, spray cooling in which high-pressure water is sprayed on the roll surface is performed.
[0003]
[Problems to be solved by the invention]
In spray cooling, it is necessary to supply a large amount of high-pressure cooling water in order to increase the cooling efficiency, and this supply device is also large. In recent years, high-speed rolls using steel materials with excellent wear resistance have been used, but the high-speed rolls are inferior in thermal conductivity and have a larger heat crown than conventional rolls, so they must be cooled with a large amount of cooling water. There was a problem of having to.
[0004]
The present invention has been developed to solve the above-described problems. That is, an object of the present invention is to provide a roll cooling device that improves the cooling efficiency of a rolling roll of a hot rolling mill and further reduces the occurrence of heat crown.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the invention of claim 1, the cooling pads for spraying the cooling liquid onto the surface of the rolling roll are stacked in multiple stages, and the second cooling pad moves on the upper surface or the lower surface of the first cooling pad. a roll cooling device configured to contact the roll surface, the cooling pad comprises a contact portion in contact with the rolling roll surface, this gap constitutes a rolling roll surface and the gap in a state where the contact portion is in contact A guide portion that extends in an arc shape along the surface of the rolling roll, and a slit-like nozzle portion that is provided in the axial direction of the rolling roll between the guide portion and the contact portion and blows a cooling liquid onto the surface of the rolling roll. Yes, and the gap in one of the cooling pad of the first stage and second stage extends toward the other of the cooling pad, cooling liquid that has passed through the said gap is the contact portion of the other of the cooling pad, Square is blocked in so that it does not reach the gap between the cooling pad and is guided between both cooling pad.
[0006]
When the contact part of the cooling pad is brought into contact with the surface of the rolling roll, a gap is formed between the arc-shaped guide part along the roll surface and the roll surface, and cooling is performed by flowing a cooling liquid from the nozzle part into this gap. The liquid flow rate is increased, and a high cooling effect is obtained with a small amount of water flow. In addition, the cooling area can be easily expanded by using multiple cooling pads, and even if the roll diameter changes, a gap suitable for the surface shape of the roll can be formed, thereby avoiding a decrease in cooling efficiency. be able to. Moreover, the inflow of heat to the roll center can be prevented by bringing the first stage cooling pad closer to the rolled material. Moreover, the pressure of the cooling liquid supplied can be made low compared with the spray system which sprays the conventional high pressure water.
[0007]
According to a second aspect of the present invention, the nozzle portion of the first-stage cooling pad is provided with a slit width variable mechanism that changes the slit width in the rolling roll axial direction with a mask to make the cooling width variable.
[0008]
Since the first stage cooling pad is provided with a slit width variable mechanism that changes the blowing width of the coolant, the heat crown shape can be controlled, and the thickness of the rolled material in the sheet width direction is made uniform. be able to.
[0009]
In the invention of claim 3, the first stage cooling pad is set on the roll surface in the vicinity of the rolling material of the upper and lower rolling rolls sandwiching the rolling material.
[0010]
The rolling roll is heated by the rolled material and thermally expands to cause a heat crown and the like. By setting the upper and lower first stage cooling pads on the roll surface close to the rolled material, the cooling start position in the roll circumferential direction can be made near the heat entry position, effectively preventing heat from entering the roll. it can.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a cross-sectional view showing an embodiment of a roll cooling device according to the present invention. A pair of rolling rolls (work rolls) 2 are provided with the rolled material 1 in between. 2a shows an upper rolling roll, 2b shows a lower rolling roll. The roll cooling device 3 is provided in each of the upper rolling roll 2a and the lower rolling roll 2b, and is provided at substantially the same position with the rolled material 1 in between.
[0012]
In FIG. 1, the roll cooling device 3 of the present embodiment is composed of cooling pads 4 and 5 arranged in two stages, and the one closer to the rolled material 1 is provided above or below the first stage cooling pad 4. This is the second stage cooling pad 5. The first stage cooling pad 4 is fixed to a pad support member 6, and the pad support member 6 is connected to a device (not shown), and the roll cooling device 3 is attached to or detached from the rolling roll 2 by this device.
[0013]
The upper surface or the lower surface of the first-stage cooling pad 4 is provided with a rail 7 in the rolling direction, and a slide block 8 that is engaged with and slides on the rail 7 is provided. The slide block 8 serves as the second-stage cooling pad 5. It is attached to the lower surface or the upper surface. Thereby, the second stage cooling pad 5 slides on the upper surface or the lower surface of the first stage cooling pad 4 and comes into contact with the surface of the rolling roll. A cylinder 9 is provided between the pad support 6 or the first-stage cooling pad 4 and the second-stage cooling pad 5, and the second-stage cooling pad 5 is brought into contact with or separated from the surface of the rolling roll.
[0014]
FIG. 2 is a detailed view of the roll cooling device 3 mounted on the upper rolling roll 2a. The roll cooling device 3 mounted on the lower rolling roll 2b has a substantially similar structure. On the rolling roll surface side of each cooling pad 4, 5, a contact portion 11 that is in close contact with the surface of the rolling roll is provided in the lower portion, and the upper portion is slightly spaced from the roll surface with the contact portion 11 being in close contact with the surface of the rolling roll. The guide part 12 which comprises is provided. A rail 7 extending in the rolling direction is provided on the upper surface of the first stage cooling pad 4, and a slide block 8 that engages and slides on the rail 7 is attached to the lower surface of the second stage cooling pad 5.
[0015]
A slit-like nozzle 13 having a width substantially equal to the width of the rolling roll 2 is provided at the boundary between the contact portion 11 and the guide portion 12, and the cooling liquid is blown into a gap formed by the guide portion 12 and the roll surface to cool the surface of the roll. . A slit 14 is connected to the nozzle 13, and the slit 14 is connected to a header 15. A coolant is supplied to the header 15 from a coolant supply pipe 16. The first-stage cooling pad 4 is provided with a variable slit width mechanism 17 to make the temperature distribution in the width direction of the rolling roll 2 uniform by expanding and contracting the width of the slit 14 and preventing the thermal roll from being generated on the rolling roll 2. To do.
[0016]
3 is a cross-sectional view of the slit width varying mechanism 17 partially cut away, and FIG. 4 is a cross-sectional view taken along the line XX of FIG. 5 is a cross-sectional view taken along the line YY of FIG. A rectifying plate 21 having a rectifying hole 22 is provided between the slit 14 and the header 15, and the coolant supplied to the header 15 flows into the slit 14 through the rectifying hole 22. Since the coolant flowing into the slit 14 further enters and diffuses into the mask groove 18 on the rolling roll side, the slit 14 exiting this has a structure in which the slit 14 has a rectifying mechanism as shown in FIG. A rectangular mask groove 18 having rounded corners surrounding the slit 14 and the header 15 is provided, and a grooved belt-shaped mask 19 is fitted in the mask groove 18. As shown in FIG. 6, the mask 19 is moved in the mask groove 18 by toothed pulleys 20 provided at both corners of the mask groove 18 on the rolling roll 2 side. A guide pulley 20 a is provided at the other corner of the mask groove 18. As shown in FIG. 3, the mask 19 includes two grooved belts. By rotating the toothed pulley 20, the mask tip 19 a moves in the width direction of the slit 14, and the length of the slit 14 in the width direction is set to the mask 19. The slit width is variable. The left and right toothed pulleys 20 are rotated in opposite directions by a pulley driving device 23 driven by a hydraulic motor or the like. As a result, the width of the slit 14 is enlarged or reduced left and right with the width center as the center.
[0017]
Next, the operation of this embodiment will be described. First, after the cylinder 9 is contracted and the second-stage cooling pad 5 is retracted from the first-stage cooling pad 4, the pad support 6 is moved by a device (not shown), and the upper and lower roll cooling devices 3 are rolled up and down. It sets so that it may respectively approach the roll 2, and the contact part 11 of the 1st-stage cooling pad 4 may contact the position near the rolling material 1 on the surface of the rolling roll 2. As a result, a slight gap is formed along the roll surface between the guide portion 12 of the first-stage cooling pad 4 and the roll surface. Next, the cylinder 9 is extended to bring the contact portion 11 of the second stage cooling pad 5 into contact with the rolling roll 2. Thereby, a slight gap is formed between the guide portion 12 of the second stage cooling pad 5 and the roll surface along the roll surface. Next, the toothed pulley 20 is rotated so that the width of the slit 14 is a width corresponding to the width of the rolled material 1. Now that the roll cooling preparation is complete, the coolant is supplied to the headers 15 of the cooling pads 4 and 5, and the coolant is discharged from the nozzles 13.
[0018]
In the above embodiment, the cooling pad has two stages. However, when the cooling area is increased, or when the guide portion 12 is as close as possible to the roll surface and the gap between the roll surface and the guide portion 12 is further reduced. It is better to have three or more stages.
[0019]
【The invention's effect】
As described above, the roll cooling device of the present invention has the following effects.
(1) A cooling pad having an arc shape along the surface of the rolling roll is set in the vicinity of the surface of the upper and lower rolls, the cooling liquid is allowed to flow through a slight gap between the roll surface and the cooling pad, and the flow rate is increased. High cooling effect can be obtained by the amount. As a result, the amount of the coolant can be reduced, and the pressure of the coolant supplied can be reduced as compared with the conventional spray method in which high-pressure water is sprayed, so that the capacity of the coolant supply facility can be reduced.
(2) By setting the first-stage cooling pad close to the rolled material, the cooling start position can be brought closer to the rolling region of the roll, and the flow of heat from the rolled material to the center of the roll can be prevented. Can do.
{Circle around (3)} By using a plurality of cooling pads, the cooling area can be expanded and the optimum coolant gap can be maintained even if the roll diameter changes.
(4) By providing a device for changing the width of the slit for discharging the cooling liquid in the upper and lower first stage pads, the heat crown shape of the rolling roll can be controlled.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a roll cooling device according to the present invention.
FIG. 2 is an enlarged view of the roll cooling device shown in FIG.
FIG. 3 is a plan view showing a slit width varying mechanism.
4 is a cross-sectional view taken along the line XX of FIG.
5 is a YY cross-sectional view of FIG. 4;
FIG. 6 is a detailed view of a mask, a mask groove and a toothed pulley.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rolled material 2 Roll 3 Roll cooling device 4 1st stage cooling pad 5 2nd stage cooling pad 6 Pad support material 7 Rail 8 Slide block 9 Cylinder 11 Contact part 12 Guide part 13 Nozzle 14 Slit 15 Header 16 Coolant supply pipe 17 Slit width variable mechanism 18 Mask groove 19 Mask 20 Toothed pulley 20a Guide pulley 21 Rectifier plate 22 Rectifier hole 23 Pulley drive mechanism

Claims (4)

A roll cooling device configured such that cooling pads for spraying a cooling liquid on the surface of the rolling roll are stacked in multiple stages so that the second stage cooling pad moves on the upper surface or the lower surface of the first stage cooling pad and comes into contact with the roll surface. Each cooling pad includes a contact portion that contacts the rolling roll surface, and a guide portion that forms a gap with the rolling roll surface in a state where the contact portion is in contact, and the gap extends in an arc shape along the rolling roll surface. If, have a, a slit-shaped nozzle portion provided in the rolling roll axial direction spraying a cooling liquid on rolling roll surface between the contact portion and the guide portion,
The gap in one cooling pad of the first stage and the second stage extends toward the other cooling pad, and the coolant passing through the gap is cooled by the contact part of the other cooling pad. A roll cooling device, wherein the roll cooling device is prevented from reaching a gap between the pads and is guided between both cooling pads .   2. The roll cooling apparatus according to claim 1, further comprising a slit width variable mechanism in the nozzle portion of the first stage cooling pad, wherein the slit width in the rolling roll axial direction is changed by a mask to change the cooling width.   2. The roll cooling apparatus according to claim 1, wherein the first stage cooling pad is set on a roll surface in the vicinity of the rolled material of the upper and lower rolling rolls sandwiching the rolled material. Rails are provided on the upper or lower surface of the first stage cooling pad,
A slide block that engages and slides on the rail is provided on the lower surface of the second-stage cooling pad so that the second-stage cooling pad can move on the upper surface or lower surface of the first-stage cooling pad and come into contact with the roll surface. Or the roll cooling device of Claim 1 provided in the upper surface.

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