JP2725514B2 - Rolling roll preheating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling roll preheating apparatus for preheating a rolling roll used for hot rolling of a metal sheet prior to use.

[0002]

2. Description of the Related Art A hot rolling roll of a metal sheet is heated by sensible heat and rolling heat of the rolled material during rolling. This heating is particularly significant at the center of the roll in contact with the rolled material. Accordingly, the roll crown is designed and provided so as to have an appropriate roll shape during rolling in consideration of the thermal expansion of the roll central portion due to the heating, that is, the heat crown. For this reason, in the rolling immediately after the roll change, the roll crown is insufficient due to insufficient heat crown, and the roll is not rolled into an appropriate shape.

Therefore, before assembling the rolling rolls into a roll stand, preheating is performed by a preheating device as disclosed in Japanese Utility Model Laid-Open No. 1-105004. 7 and 8
FIG. 2 is an elevation view and a plan view of the above-mentioned conventional preheating device. 7 and 8, reference numeral 1 denotes an upper roll, and 2 denotes a lower roll.
The upper and lower rolls 1 and 2 are stacked in two stages, placed on the receiving stand 4 and the truck is installed at the preheating device position,
It is rotated at a constant speed by a roll rotation device 6. The heating device main body 3 is mounted close to the rolls 1 and 2, and heats a region in the longitudinal direction of the roll where heat crowning is required. The heating device main body 3 is composed of a plurality of heating units divided in the longitudinal direction of the roll, and a surface thermometer 7 and a heating temperature controller 10 are provided for each unit.
As shown in FIG. 8, the roll rotation device 6 is driven by a motor 62, and is in contact with the upper roll 1 and the lower roll 2 at the same time to transmit rotation by frictional force. -61 is used. The heating device 3 is a hydraulic cylinder-8
1 and a base 82, the heating device can be moved back and forth in the direction of the arrow by the driving device 8, and after the upper and lower rolls 1 and 2 are set, they are set so as to be as close as possible to the surfaces of these rolls. To preheat.

[0004]

The above-mentioned apparatus for preheating a rolling roll preheats a rolling roll at 0 to 30 ° C. to 60 to 100 ° C. in order to obtain a required heat crown. 500 large rolling rolls
Heat is applied from the roll surface by radiation, heat transfer, and heat conduction from a high-temperature heat source of up to 1200 ° C.

[0005] At this time, the heat transfer in the rolling roll is in an unsteady state, and the vicinity of the roll surface rises rapidly, but it takes a long time until the inside of the roll rises. As a result, the temperature near the roll surface becomes high until the required crown is obtained, and easily becomes 120 ° C. or more. On the other hand, it is desirable that the temperature near the roll surface is kept at 120 ° C. or less due to the material.

For this reason, it has been very difficult to heat the roll to a temperature of 60 to 100 ° C. while maintaining the temperature near the roll surface at 120 ° C. or lower using only a conventional heating device.
That is, when the temperature near the roll surface exceeds 120 ° C.,
The heating is stopped, and after the temperature near the surface is reduced by the heat transfer into the roll, the heating is restarted. As described above, it is necessary to repeat heating and stopping until the required heat crown is obtained, and there has been a problem that heating takes a long time. An object of the present invention, while maintaining the surface temperature of 120 ° C. or less, rolling for easily heated in a short time rolling rolls to a required temperature Russia - to provide a preheater Le.

[0007]

SUMMARY OF THE INVENTION A rolling roll according to the present invention
The pre-heating device is a pre-heating device of a rolling roll for pre-heating while rotating the rolling roll.
A pair of left and right that can be approached so as to sandwich the rolling roll from both sides
Between the heating unit and the pair of left and right heating units.
And the rolling roll is disposed above the upper roll.
A cooling unit, and heating from the heating unit.
And the rolling roll by removing heat from the cooling unit.
It is characterized by preheating.

[0008]

According to the present invention, there is provided a rolling roll preheating apparatus comprising:
Is provided so as to sandwich the rolling roll from both sides while rotating
The roll surface is heated by a pair of left and right heating units
At the same time, heat is removed from the roll surface heated to a higher temperature than the upper cooling unit , thereby suppressing the rise in temperature near the roll surface. That is, since the temperature near the roll surface is higher than the inside of the rolling roll, only the heat is removed from the vicinity of the roll surface during cooling from the cooling unit, and the temperature near the roll surface decreases. At the same time, the temperature deviation between the inside of the roll and the vicinity of the surface is reduced, so that uniform preheating can be performed in the roll cross section.

However, the amount of heat removed from the cooling unit is set in advance so as to satisfy the following relational expression. From the balance between heat input and heat output near the roll surface, Q _IN = Q _out + Q _H + Q _T (1) In order to lower the temperature near the roll surface, the heat content QH must be reduced. From Q _H <0 ………………………………………………………………………………………… (2) From equations (1) and (2), Q _out > Q _IN −Q _T (3) where Q _out : cooling unit Q _IN : Heat input to the roll surface by the heating unit Q _T : Heat transfer from near the roll surface to the inside of the roll Q _H : Increase in heat content near the roll surface due to heat If the temperature near the surface becomes lower than the required temperature, the operation is stopped. As a result, it is possible to preheat to a required temperature while keeping the roll surface temperature rise below a predetermined temperature, and to obtain a required heat crown.

[0010]

1 and 2 are an elevational view and a plan view, respectively, of a preheating apparatus according to the present invention, which is an embodiment of the present invention. This drawing is an explanatory view in which after a rolling roll is processed, maintained, and assembled in a roll shop, the roll is heated while being placed on a transport trolley during transportation to a hot rolling mill.

1 and 2, 1 is an upper roll of a rolling roll, 2 is a lower roll, and 3 is a heating unit provided with a plurality of heating heaters divided in the longitudinal direction of the roll. The upper and lower rolling rolls on both sides
A surface thermometer 7 and a heating temperature controller 10 are provided for each unit. Numeral 4 denotes a transport trolley which is a cradle for rolls, numeral 5 denotes a cooling device main body, numeral 6 denotes a roll rotating device comprising a contact drive roll 61 and a motor 62, numeral 8 denotes a heating device main body comprising a driving hydraulic cylinder 81 and a gantry 82. The driving device 9 includes a driving device 91 for driving the cooling device main body 5 and a cooling device source 92.
, A cooling device controller (in this embodiment, an air volume controller), and 12 a sealing device for the cooling device body 5. As shown in FIGS. 1 and 2 , the preheating device of the present invention comprises a heating device main body 3 and a heating temperature controller 10.
The cooling unit comprises a pair of left and right heating units comprising a heating device driving device 8, a cooling device body 5, a cooling temperature controller 11 and a cooling device comprising a cooling device driving device 9. In this embodiment, in order to simplify the configuration, the contact drive roll 61 which simultaneously contacts the upper roll 1 and the lower roll 2 and transmits rotation by frictional force is used. The roll 1 and the lower roll 2 may be driven separately, or a coupling may be fitted to the neck of the roll and driven by a motor. It is preferable to use a heat-resistant rubber roll as the material of the contact drive roll 61 in order to secure the frictional force and prevent the roll from being damaged.

Next, the operation of the preheating apparatus will be described.
Since the preheating device heats the roll while rotating the roll, the temperature becomes uniform in the circumferential direction of the roll. First, the surface temperature of the upper roll 1 of the rolling roll is heated while being measured by the roll surface thermometer 7. Then, the cooling device main body 5 is operated using air as a cooling medium to forcibly lower the temperature near the roll surface. Then, when the roll surface temperature falls to a predetermined temperature, the cooling device 5 is stopped, and the heating device 3 is operated again. In this manner, heating is performed for a predetermined time to obtain a required heat crown. The heating device main body 3 is composed of a heating unit provided with a plurality of heating heaters divided in the longitudinal direction of the roll. If the heating unit having a width of 100 mm is placed symmetrically on each side of the heating unit at the center, the heating range for heat crowning is a minimum of 800 mm from the center in the longitudinal direction of the roll to both ends. Up to 16
It can be increased or decreased in the range of 00 mm. In this embodiment, air is used as a cooling medium and cooling is performed by this spraying. However, another gas such as N2 may be sprayed.
The same effect can be obtained by using water spray or contact cooling with a water-cooled roll.

Table 1 shows the specification conditions of the rolling roll. Table 2 shows heating conditions such as the heating heater temperature, the roll surface temperature restriction, and the use of a cooling device.

[0014]

[Table 1]

[0015]

[Table 2]

Next, the results of preheating by changing the heating conditions shown in Table 2 to 1 to 4 are shown in FIGS. Heating conditions 1-2
Is an example in which preheating is performed by a conventional preheating device, heating condition 3 is a case where a cooling device is not used as a comparative example, and heating condition 4 is an example where the device of the present invention is used. (A) of FIG.
And (b) are graphs showing the relationship between the heating time, the roll surface temperature, and the heat crown in the case where the heating condition 1 was used, and (a) and (b) in FIG. Graphs showing the relationship between the heating time, the roll surface temperature and the heat crown, respectively, and FIGS. 5 and 6 are graphs showing the relationship between the heating time and the heat crown when heating is performed under the heating conditions 3 and 4, respectively.
Fig. 3 (b) when preheating was performed with the conventional apparatus under heating condition 1.
As shown in the figure, it took 43.5 minutes to reach the target heat crown (230 μm), and the heating temperature under heating condition 2 was 12
When the temperature was raised to 00 ° C., a required heat crown was obtained in 25 minutes as shown in FIG. 4 (B), but the roll surface temperature at that time was restricted as shown in FIG. 4 (A). Temperature (in this embodiment, 120 ° C.). Heating condition 3
When the heating is performed in consideration of the roll surface temperature constraint described above, it takes 30 minutes as shown in FIG. 5. On the other hand, when preheating is performed by the apparatus of the present invention, as shown in FIG. .5 minutes.

As described above, by using the roll cooling device, the temperature in the vicinity of the roll surface can be maintained at a predetermined temperature (120 ° C. in this embodiment) or less,
It can be seen that the target heat crown (230 μm) has been obtained.

[0018]

As described above, according to the rolling roll preheating apparatus of the present invention, the required heat crown can be rolled in a short time while maintaining the surface temperature of the rolling roll below the temperature at which the material does not deteriorate. Can be assigned to a role.

[Brief description of the drawings]

FIG. 1 is an elevation view of a preheating device of the present invention, which is an embodiment of the present invention,

FIG. 2 is a plan view of a preheating device of the present invention, which is an example of the present embodiment,

FIG. 3 is a graph showing the relationship between the heating time, the roll surface temperature (a) and the heat crown (b) when heating is performed under heating condition 1 in the present embodiment;

FIG. 4 is a graph showing the relationship between the heating time, the roll surface temperature (a) and the heat crown (b) when heating is performed under heating condition 2 in the present embodiment;

FIG. 5 is a graph showing a relationship between a heating time and a heat crown when heating is performed under heating condition 3 in the present embodiment;

FIG. 6 is a graph showing a relationship between a heating time and a heat crown when heating is performed under heating condition 4 in the present embodiment.

FIG. 7 is an elevation view of a conventional preheating device,

FIG. 8 is a plan view of a conventional preheating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper roll 2 Lower roll 3 Heating device main body 4 Roll transporting trolley (receiving stand) 5 Cooling device main body 6 Roll rotating device 7 Roll surface thermometer 8 Heating device main body driving 9 Cooling device main body driving device 10 Heating temperature controller 11 Cooling temperature Controller 12 Cooler seal 61 Contact drive roll 62 Motor 81 Hydraulic cylinder 82 Mount 91 Drive unit 92 Cooling source main unit.

Claims (1)

(57) [Claims] An apparatus for preheating a rolling roll for preheating while rotating the rolling roll , wherein the rolling roll is sandwiched from both sides with respect to the rolling roll.
Between the pair of left and right heating units and the pair of right and left heating units,
With the cooling unit located above the upper roll
And heating from the heating unit and cooling from the cooling unit.
An apparatus for preheating a roll, wherein the roll is preheated by removing heat.