JPH0515363Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a device that preheats only the necessary longitudinal portion of a rolling roll to a desired temperature.

[Prior art] Conventionally, rolling of metal sheets involves adjusting the dimensional structure of the metal sheets to be rolled and the order of rolling to create a rolling cycle.As the heat crown increases, materials with strict dimensional accuracy (low crown materials) )
Avoid rolling. Changes in the heat crown of the rolling roll in this case are shown in FIGS. 5 to 7. When a new rolling roll is installed, the heat crown is zero, and the shape of the roll and the temperature distribution of the roll at this time are as shown in FIG. When a new rolling roll is installed and about 10 hot rolled strips are rolled, the temperature of the part of the rolling roll that is in contact with the strip increases, and the temperature distribution of the roll, the heat crown of the rolling roll, and the shape of the roll change. This will change as shown in Figure 6. Furthermore, when about 20 to 40 hot-rolled strips are rolled,
The temperature of the part of the roll in contact with the strip further increases, and the temperature distribution of the roll, the heat crown of the roll, and the shape of the roll change as shown in FIG. The heat crown in this state is the most preferable value for obtaining the accuracy of plate thickness and product shape. Further, in this state, the heat input and heat output to the rolling roll are balanced, and thereafter the temperature distribution of the rolling roll and the heat crown of the rolling roll are kept almost constant, and the shape of the rolling roll gradually changes due to wear. In other words, as shown in Fig. 8, after the rolling starts with the new rolls, until about 30 rolls have been rolled,
The heat crown of the rolling roll changes greatly and is unstable, and after this point it remains stable.

In rolling operations, we take advantage of this property to roll materials with less stringent requirements for plate thickness and product shape accuracy for the first 30 rolls after rolling with the new rolls, and roll materials with stricter requirements for accuracy after that. The order of rolling was determined.

On the other hand, the surface quality of the hot-rolled strip deteriorates as the number of rolls passes from the start of rolling with a new roll, so materials that require a high level of surface quality must be rolled as early as possible. For materials that require high plate thickness, product shape, and surface quality, there is a high chance of rolling within one rolling cycle from installing a new rolling roll to changing the next rolling roll. almost 25%
was limited to.

[Problems that the invention aims to solve] In recent years, the production ratio of materials that require high plate thickness, product shape, and surface quality has increased.
It now accounts for over 25% of all rolled materials.
Therefore, rolls that could still be used for rolling low-grade materials had to be rearranged and used.
Problems arose in that the utilization rate decreased due to an increase in roll consumption and an increase in changeover time. The present invention was developed to solve these problems, and by providing a device that partially heats the rolls in advance, the heat crown of the rolling rolls can be adjusted to the thickness and product shape immediately after the new rolls are reassembled. The most preferable values for and stable, plate thickness, product shape,
The purpose of this method is to enable rolling of materials that require high surface quality immediately after reassembly.

[Means for Solving the Problems] A roll preheating device used to achieve the above object includes: a pedestal that supports a pair of upper and lower rolls on a chock basis; a roll rotation device that rotates the rolls; A heating device for a rolling roll having a single heating unit or a plurality of heating units arranged in a line in the width direction provided in the central part of the rolling roll in the width direction, and temperature of each rolling roll provided corresponding to the heating unit. The roll heating device is provided corresponding to the detector and each rolling roll temperature detector, and the rolling roll heating device has an electric heater on a surface facing the rolling roll, and the rolling roll heating device is close to and isolated from the rolling roll. The roll rotation device includes a contact drive roll made of a heat-resistant rubber roll that contacts the upper and lower rolls at the same time, and a drive mechanism that rotates the contact drive roll, each of which is independent of the other. It is possible to set the target temperature by setting the target temperature, and this is realized by having a configuration including a temperature controller that controls the corresponding heating unit so that the temperature detected by the corresponding rolling roll temperature detector is controlled to the target temperature. .

[Function] While the roll rotation device rotates the roll, the roll heating device heats the upper and lower rolls. Since the rolling roll heating device is divided in the width direction of the rolling roll and can perform individual temperature control for each, a heat crown can be obtained to achieve the target temperature of each temperature controller, and the upper and lower rolling rolls can be preheated simultaneously as a set. By matching the heat crowns of the upper and lower rolling rolls, a stable target heat crown can be obtained before the rolling rolls are rearranged. As a result, a product with a good shape can be obtained even when the rolling operation is performed immediately after the rolling rolls are rearranged.

[Embodiment of the invention] An embodiment of the invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a cross-sectional view of the mill roll preheating device according to this invention, viewed from the longitudinal direction of the mill roll. FIG. 2 shows a schematic view of this preheating device from above. The upper roll 1 and the lower roll 2 are stacked in two layers, upper and lower, and placed on a pedestal 4 having a trolley and installed at a preheating device position.
It is rotated at a constant speed by a roll rotation device 5. A heating device main body 3 is mounted close to the rolls 1 and 2, and heats the range in the longitudinal direction of the rolls where heat crowning is required. Heating device main body 3
consists of a plurality of heating units divided in the longitudinal direction of the roll, and each unit is provided with a surface thermometer 6 and a temperature controller 7. For example, width
If an 800 mm heating unit is placed at the longitudinal center of the rolling roll, and four 100 mm wide heating units are placed symmetrically on each side, the area to be heated for heat crowning will be within the longitudinal direction of the roll. Minimum 800mm to maximum 1600mm from center to both ends
It can be increased or decreased within the range of mm. The roll rotation device is driven by a motor 52 as shown in FIG.
A contact drive roll 5 that simultaneously contacts the upper roll 1 and the lower roll 2 and transmits rotation by frictional force.
1 is used. In this case, it is also possible to configure the upper roll 1 and the lower roll 2 to be driven separately.
Alternatively, as shown in FIG. 3, a coupling 53 may be fitted into the neck portion of the roll and driven by a motor 52. It is preferable to use a heat-resistant rubber roll as the material for the contact drive roll in order to ensure frictional force and prevent scratches on the rolling roll. The heating device 3 can be moved forward and backward in the direction of the arrow by a heating device drive device 8 having a hydraulic cylinder 81 etc. and an indicating device 82, and after the upper and lower rolls 1 and 2 are set, it is moved as close as possible to the surfaces of these rolls. is set. FIG. 4 shows details of the heating device main body 3 shown in FIGS. 1 and 2. Insulation material 8
A heater element 11 is arranged on the surface. The heater element 11 is arranged with a curvature that approximately follows the circumference of the rolling roll. The heat insulating material 9 is supported by a steel material 12. Further, a seal hood 10 made of heat-resistant rubber or the like is provided around the heating device body 3 to prevent heat from dissipating. As described above, the heater element 11 is divided into several units (heating units) in the width direction. The heat crowning value is 80℃~100℃ on the surface of the roll, and 60℃~60℃ in the center.
It is 70℃. In addition, as a heating method with a different configuration from this example, it is also possible to place a heater that can maintain a surface pressure of a certain level or higher on the surface of the rolling roll in close contact with the entire circumference of the roll, and heat the entire necessary range in the length direction. .

[Effects of the invention] By heating the rolls using the roll heating device of the invention, the heat crown of the rolls can be set to the most preferable value for obtaining the plate thickness and product shape immediately after the new rolls are reassembled. Since it can be stabilized, rolling work for adjusting the heat crown of the rolling roll, that is, rolling of heated material is not required, and it is possible to roll materials that require high plate thickness, product shape, and surface texture. This makes it possible to improve the rolling efficiency of hot rolling and reduce the amount of rolling rolls used.
Furthermore, the configuration of the rolling cycle has become easier, and in particular, it has become possible to improve the efficiency of direct rolling of hot pieces by continuous casting.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a preheating device for a rolling roll according to an embodiment of the present invention, viewed from the longitudinal direction of the rolling roll, Fig. 2 is a schematic diagram similarly viewed from above, and Fig. 3 is a schematic diagram of a roll rotation drive device. Figure 4 is a detailed diagram of the heating device, Figures 5, 6, and 7 are diagrams showing the heat crown of the roll, the shape of the roll, and the temperature distribution of the roll in the conventional technology. 6 shows the condition immediately before installing the rolling rolls, after installing the rolling rolls and rolling 10 hot-rolled strips, and FIG. 7 shows the state after rolling 20 more hot-rolled strips. FIG. 8 is a graph showing the number of hot-rolled strips rolled after a new rolling roll is installed in the prior art, the shape of the roll with the heat crown, and the temperature distribution of the roll. 1...Upper roll, 2...Lower roll, 3...
Heating device main body, 4... pedestal, 5... roll rotating device, 6... surface thermometer, 7... temperature controller, 8...
... Heating device drive device, 9 ... Heat insulating material, 10 ... Heat dissipation prevention body, 11 ... Heater element, 12
...Steel plate.

Claims (1)

[Scope of utility model registration request] A pedestal for supporting a pair of upper and lower rolls of a rolling roll preheating device for a hot tandem mill for metal plate materials together with the chock, a roll rotating device for rotating the rolling rolls, and a single unit provided at the center in the width direction of the rolling rolls. , or a rolling roll heating device having a plurality of heating units arranged side by side in the width direction, each rolling roll temperature detector provided corresponding to the heating unit, and a rolling roll heating device corresponding to each rolling roll temperature detector. and a temperature controller that controls the corresponding heating unit so that the temperature detected by the corresponding rolling roll temperature detector is controlled to the target temperature. In the preheating device, the rolling roll heating device has an electric heater on a surface facing the rolling roll, the rolling rolling heating device has a moving device in a direction approaching and separating from the rolling roll, and a rolling roll rotating device. 1. A preheating device for a rolling roll for a hot tandem mill, comprising: a contact driving roll made of a heat-resistant rubber roll that contacts upper and lower rolling rolls at the same time; and a driving mechanism for rotating the contact driving roll.