JPH05237520A - Preheating device for rolling roll - Google Patents

Abstract

PURPOSE:To impart a required heat crown while the surface of a rolling roll is kept under a material deteriorating temperature by providing a heating unit and a cooling unit in the peripheral direction of the rolling roll in a preheating device for the rolling roll. CONSTITUTION:The surface of a upper roll 1 of the rolling roll is heated while the temp. thereof is measured by a roll surface thermometer 7 and when the roll surface temperature exceeds a prescribed temperature a heating device 3 is stopped. Then, a cooling device main body 5 is operated using air as a cooling medium to forcedly lower the temperature near the roll surface. When the surface temperature of the roll falls down to a specified temperature, the cooling device 4 is stopped and the heating device 3 is operated again. In this way, heating is continued for a specified time and a required heat crown can be imparted to the rolling roll.

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 device for preheating a rolling roll used for hot rolling a metal sheet material prior to its 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 remarkable at the central portion of the roll which is in contact with the rolled material. Therefore, the rolling roll is designed and provided with a roll crown so as to have an appropriate roll shape during rolling, in consideration of the thermal expansion of the central portion of the roll due to this heating, that is, the heat crown. For this reason, in the rolling immediately after changing the rolling rolls, the roll crown is in a shortage state due to the lack of the heat crown, and the roll is not rolled into an appropriate shape.

Therefore, before the rolling roll is incorporated into the roll stand, preheating is performed by a preheating device as disclosed in Japanese Utility Model Laid-Open No. 1-105004. 7 and 8
FIG. 3 is an elevational view and a plan view of the above-mentioned conventional preheating device. In FIGS. 7 and 8, 1 is the upper roll and 2 is the lower roll.
And the upper and lower rolls 1 and 2 are stacked in two stages on the pedestal 4 and the trolley is installed at the preheater position.
It is rotated at a constant speed by the roll rotating device 6. The heating device main body 3 is mounted close to the rolls 1 and 2, and heats a range in which heat crowning is required in the longitudinal direction of the roll. 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 a contact drive roll that is driven by a motor 62 and simultaneously contacts the upper roll 1 and the lower roll 2 to transmit the rotation by frictional force. -Le 61 is used. The heating device 3 is a hydraulic cylinder-8.
It is possible to move back and forth in the direction of the arrow by the heating device main body driving device 8 having 1 and the pedestal 82, and after the upper and lower rolls 1 and 2 have been set, set them so as to be as close as possible to the surface of these rolls. , Preheat.

[0004]

The above-mentioned rolling roll preheating device 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
The surface of the roll is heated by radiation, heat transfer and heat conduction from a high temperature heat source of up to 1200 ° C.

At this time, heat is transferred in the rolling roll in an unsteady state, and the temperature near the roll surface rises rapidly, but it takes a long time to rise inside the roll. As a result, the temperature near the surface of the roll becomes high until the required crown is obtained, and it easily becomes 120 ° C. or higher. On the other hand, it is desirable to keep the temperature near the roll surface at 120 ° C. or lower due to the material.

Therefore, it has been very difficult to heat the roll temperature to 60 to 100 ° C. while keeping the temperature near the roll surface at 120 ° C. or lower only by the 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 decreases due to the heat transfer into the roll, the heating is restarted. As described above, it is necessary to repeat heating and stopping until the temperature at which the required heat crown is obtained, and there is a problem that it takes a long time for heating. It is an object of the present invention to provide a rolling roll preheating device for easily heating a rolling roll to a required temperature in a short time while keeping the surface temperature at 120 ° C or lower.

[0007]

The above objects of the present invention are as follows.
This is solved by providing a heating unit and a cooling unit in the circumferential direction of the rolling roll in a preheating device for a rolling roll of a metal plate.

[0008]

The roll roll preheating apparatus of the present invention removes heat from the cooling unit from the surface of the roll heated to a high temperature by the heating unit provided in the circumferential direction of the rolling roll to suppress the rise of the temperature near the roll surface. Is to do. That is, since the temperature near the roll surface is higher than that inside the rolling roll, only the heat is removed from the vicinity of the roll surface during cooling by the cooling unit, and the temperature near the roll surface is lowered. At the same time, the temperature deviation between the inside of the roll and the vicinity of the surface becomes small, and uniform preheating is possible in the cross section of the roll.

However, the amount of heat removed from the cooling unit is preset so as to satisfy the following relational expression. From the balance of 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 Q _H must decrease. From Q _H <0 …………………… (2) From the formulas (1) and (2), Q _out > Q _IN −Q _T ………… (3) where Q _out : Cooling unit The amount of heat removed from the roll surface by Q _IN : The amount of heat input to the roll surface by the heating unit Q _T : The amount of heat transferred from the vicinity of the roll surface to the inside of the roll Q _H : The increase in the heat content near the roll surface It stops when the temperature near the surface falls below the required temperature. As a result, it is possible to preheat to the required temperature while suppressing the roll surface temperature rise below the predetermined temperature, and obtain the required heat crown.

[0010]

1 and 2 are an elevational view and a plan view, respectively, of a preheating device of the present invention which is an example of this embodiment. In addition, this drawing is an explanatory view of heating the rolling rolls after they are processed / maintained / assembled in the roll shop and then placed on the transportation carriage during transportation to the hot rolling mill.

In FIGS. 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. In this heating device body, a surface thermometer 7 and a heating temperature controller 10 are provided for each unit. Reference numeral 4 is a carrier truck that is a roll receiving base, 5 is a cooling device main body, 6 is a roll rotating device including a contact drive roll 61 and a motor 62, 8
Is a heating device main body driving device including a driving hydraulic cylinder 81 and a pedestal 82, 9 is a cooling device main body driving device including a driving device 91 for driving the cooling device main body 5 and a cooling device source 92, and 11 is cooling temperature adjustment Reference numeral 12 denotes a sealing device for the cooling device main body 5 (in this embodiment, an air flow controller). As shown in FIGS. 1 and 2, the preheating device of the present invention comprises a heating unit including a heating device main body 3, a heating temperature controller 10 and a heating device main body driving device 8, a cooling device main body 5, a cooling temperature controller 11 and a cooling device main body. And a cooling unit including the drive unit 9. In the present embodiment, in order to simplify the structure, the contact drive roll 61 which simultaneously contacts the upper roll 1 and the lower roll 2 and transmits the rotation by frictional force is used, but the upper roll is used. The roll 1 and the lower stage roll 2 may be configured to be driven separately, or may be configured to be driven by a motor by fitting a coupling to the neck portion of the roll. It is preferable to use a heat-resistant rubber roll as the material of the contact drive roll 61 in order to secure the friction force and prevent the rolling roll from being scratched.

Next, the operation of the preheating device will be described.
Since this preheating device heats the rolling roll while rotating it, the temperature becomes uniform in the circumferential direction of the rolling 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, and when the roll surface temperature reaches a predetermined temperature (120 ° C.) or more during heating, the heating device 3 is stopped. Then, air is used as a cooling medium to operate the cooling device body 5 to forcibly lower the temperature near the roll surface. When the roll surface temperature drops to a predetermined temperature, the cooling device 4 is stopped and the heating device 3 is activated again. In this way, heating is performed for a predetermined time to obtain the 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. For example, a heating unit having a width of 800 mm is arranged in the longitudinal direction of the rolling roll. By arranging four heating units with a width of 100 mm symmetrically on both sides, the heating range for heat crowning is 800 mm minimum from the center of the roll in the longitudinal direction to both ends. ~ Up to 16
It can be increased or decreased in the range of 00 mm. Further, in this embodiment, air was used as the cooling medium for cooling by this spraying, but other gas such as N ₂ may be sprayed, and water spray or contact cooling with a water cooling roll may be used. Also has the same effect.

Table 1 shows the specification conditions of the rolling rolls. Table 2 shows heating conditions such as heating heater temperature, roll surface temperature restriction, and use of 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 of performing preheating with 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 of using the device of the present invention. (A) of Figure 3
And (b) are graphs showing the relationship between the heating time, the roll surface temperature and the heat crown, respectively, when the heating condition is 1. The (a) and (b) of FIG. 5 and 6 are relationship graphs of heating time, roll surface temperature and heat crown, respectively, and FIGS. 5 and 6 are relationship graphs of heating time and heat crown when heated under heating conditions 3 and 4, respectively.
When preheating is performed with the conventional device under heating condition 1, Fig. 3 (b)
As shown in, it takes 43.5 minutes to reach the target heat crown (230 μm), and the heating temperature under heating condition 2 is 12
When the temperature was raised to 00 ° C, the required heat crown was obtained in 25 minutes as shown in Fig. 4B, but the roll surface temperature at that time was restricted as shown in Fig. 4A. The temperature (120 ° C. in this example) is exceeded. Heating condition 3
In the case of heating in consideration of the roll surface temperature restriction of No. 3, it takes 30 minutes as shown in FIG. 5, whereas in the case of preheating with the apparatus of the present invention, as shown in FIG. It is shortened to 5 minutes.

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

[0018]

As described above, according to the preheating device for a rolling roll of the present invention, the required heat crown is 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 applied to rolls.

[Brief description of drawings]

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

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 (b) showing the relationship between the heating time, the roll surface temperature (a) and the heat crown when the heating is carried out under the heating condition 1 in this Example.

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

FIG. 5 is a graph showing the relationship between the heating time and the heat crown in the case where the heating is performed under the heating condition 3 in this example.

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

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]

 1 Upper Roll 2 Lower Roll 3 Heating Device Main Body 4 Roll Carriage Cart (Receiving Platform) 5 Cooling Device Main Body 6 Roll Rotating Device 7 Roll Surface Thermometer 8 Heating Device Main Body Drive 9 Cooling Device Main Body Drive Device 10 Heating Temperature Controller 11 Cooling Temperature Controller 12 Cooling device seal 61 Contact drive roll 62 Motor 81 Hydraulic cylinder 82 Frame 91 Drive device 92 Cooling source body device.

Claims (1)

[Claims] 1. A preheating device for a rolling roll of metal sheet material, comprising a heating unit and a cooling unit in a circumferential direction of the rolling roll.