JPS59185508A - multi-high rolling mill - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a multi-high rolling mill for rolling plate-shaped materials, which can reduce the rolling pressure and carry out rolling with high efficiency.

[Background of the invention]

Recently, steel materials for cold regions have been heated to a temperature of 900°C during the steel manufacturing process so that they do not lose their brittleness even at low temperatures of -60 to -800°C.
It is required to roll at a low temperature of 0 or less. Therefore, conventionally rolling was done at about 1100C, so when rolling is done at a lower temperature like the upper part, the rolling reaction force is about 2 compared to normal rolling.
The rolling mill component parts may not be able to withstand this rolling pressure, resulting in a breakage accident.

For this reason, the amount of rolling per roll is limited, and it takes a lot of time to roll to the required thickness.
Because the temperature of the material cools due to long rolling times, the rolling reaction force increases, making it difficult to manufacture steel materials with sufficiently improved low-temperature brittleness using conventional rolling mills.

[Purpose of the invention]

It is an object of the present invention to provide a rolling power that enables rolling that reduces rolling reaction force, suppresses the occurrence of a slip phenomenon between a work roll and its supporting roll, and enables sufficient board biting into the rolls. The object of the present invention is to provide a multi-high rolling mill that can impart the following properties.

[Summary of the invention]

The present invention is configured such that a pair of small-diameter work rolls are used as secondary drives, and an intermediate roll that supports the work rolls and is a support roll with a larger diameter than the work rolls is used as a main drive. This is a multi-high rolling mill consisting of a secondary drive small-diameter work roll, a pair of main drive intermediate rolls, and a pair of reinforcing rolls that support the rolling load.

Next, the principle of the present invention will be explained below.

It is known that in order to reduce the rolling reaction force, it is better to reduce the diameter of the rolling work roll.

A detailed study of this revealed that the rolling reaction force decreases almost in proportion to the diameter of the work roll.

Therefore, when rolling low-temperature materials, the diameter of the work roll is reduced and the resulting rolling reaction force is small, making it possible to roll low-temperature materials with high efficiency.

On the other hand, rolling requires applying rolling processing energy to the rolled material from work rolls.

However, the torque that can be applied by driving the work roll diameter by a motor or the like decreases in proportion to the cube of the roll diameter due to the twisting strength of the roll.

Therefore, it is considered that this rolling energy can be applied by driving the rolls that support other work rolls, that is, the reinforcing rolls in a normal four-high rolling mill.

However, when the plate is biting at the beginning of rolling, if only the reinforcing roll is driven and the work roll is not driven, the roll is made of a hard material, so the coefficient of friction is small, and slippage occurs between the two rolls. This is a problem in that sufficient rolling energy is not transmitted to the work rolls.

That is, if the plate thickness before rolling is H1, the plate thickness after rolling is μ, and the coefficient of friction between the rolls is μ, the limit at which the plate, which is a rolled material, can be completely bitten by the work rolls is obtained by the following formula.

Δh=μ2R=P/K ・・・・・・・・・・・・
...α) In the above formula, Δ11=)l−h, R is the radius of the work roll, P is the rolling load, and K is the spring constant of the rolling mill.

That is, according to equation 0), the roll radius is small and the friction coefficient between the rolls is hard as described above, so the amount Δh that can be rolled down without slipping is small.

As can be seen from equation (1), this reduction in the rolling reduction amount Δh is largely influenced by the friction coefficient μ.

In other words, when driving the work rolls in a conventional rolling mill with large work rolls, the friction coefficient μ between the work rolls and the rolled material is
However, since the rolled material is soft, a sufficient rolling reduction amount of μ=0.25 can be obtained.

On the other hand, in the reinforcing roll drive, the friction coefficient μ between the rolls is large due to the roll hardness, so μ = 0.12, which is about half that of the work roll drive. Therefore, the allowable biting amount Δh into the work roll is It is approximately 1/4 of the work roll drive only due to the effect of the friction coefficient.

However, the slip limit rolling amount Δh' after the rolled material is completely bitten between a pair of work rolls is calculated by the following formula (%) (2) The rolling reduction amount is four times that when the material is bitten, and the reinforcing roll is driven. Even if normal high pressure rolling is carried out using this method, if the material is completely bitten into the rolls, slip between the rolls will not occur and will not be a problem.

After all, if the work rolls are not driven, slipping occurs between the work rolls and the reinforcing rolls when the plate is bitten at the start of rolling.

It can be seen that poor biting into the work roll occurs.

From the above points, it can be seen that even if the reinforcing roll is the main drive, at least the work roll must be driven in a sub-drive manner at the start of rolling to assist in biting the plate into the work roll.

The energy required for this auxiliary biting into the work roll is
Figure 2 shows the results obtained for the rolling mill shown in the figure. That is, when the reinforcing rolls 41 and 42 are used as the main drive in FIG. 2, the energy E that can be given from this reinforcing roll to the work rolls 43 and 44! The energy required to process and roll the rolled material 45 is E2, and the biting angle φ when the rolled material 45 starts biting into the work roll 43, 44 is defined as the angle φ between φ=α and φ=0. It is organized by the angle φ between the perpendicular line passing through the tip of the material and the center of the roll.

The rolling energy E2 becomes maximum when the angle φ decreases and φ=0. Moreover, since the cross-sectional shape of the work roll is circular, the energy E2 increases in a square root shape as φ becomes smaller.

On the other hand, the energy that can be transmitted from the reinforcing roll to the work roll increases in proportion to (α-φ).

In FIG. 2, E2>El at the hatching portion, slipping occurs between the reinforcing rolls 41, 42 and the work rolls 43, 44 in FIG.

In FIG. 2, it can be seen that if the rolled material is bitten to φ=0, rolling can be performed without slipping, but slip occurs between both rolls at the beginning of biting.

In addition, the energy deficit at the hatching part indicates the amount of energy deficit at each position φ during the process in which the rolled material is bitten, and this energy ΔE is E 1 > B at φ=0.
Under normal rolling conditions such as 2, ΔE/Eo = 0.1
It is 5 to 0.3.

As described above, the insufficient energy at the time of biting is small, so if this is applied in a auxiliary drive manner using work rolls having a reduced diameter, it is possible to carry out rolling without slipping between the rolls.

However, if the above drive were to be implemented in an actual rolling mill, the diameter of the reinforcing roll would be 1,800 to 2,000 m, which is extremely large, and the following problems would arise.

That is, the main drive is normally performed by directly connecting the driving electric motor and the rolling roll, but as mentioned above, if the diameter of the reinforcing roll is used as the main drive, the roll diameter is small, so the rotation speed of the electric motor is reduced, and therefore This is disadvantageous because it requires a large electric motor that has no choice but to increase the torque.

Therefore, in the present invention, a pair of intermediate rolls having the roll diameter necessary for the main drive are newly introduced, a pair of reinforcing rolls that directly support the rolling load are not driven, and a pair of work rolls are driven as a secondary drive. This is a 1-drive, 6-high rolling mill.

In other words, in the rolling mill of the present invention, the work roll diameter is φ1
It can be reduced from 000 to 1200 feet to φ600 to φ750, and the rolling reaction force for rolling a material with a plate width of 5000 mm can be reduced to 30 mm.
This is possible because it facilitates the design of the rolling mill, since it can be significantly reduced to ~40 inches.

That is, the above work roll is The main drive roll is used as an auxiliary drive for biting the rolled material as described above, and the main drive roll is provided as an intermediate roll.

The intermediate roll diameter is 41,000m, which is the same as the conventional work roll diameter.
If m is used, the drive system will have sufficient margin.

That is, if the diameter of the work roll is reduced, the rolling torque is reduced approximately in proportion to the 1.5th power of the diameter of the work roll, so that sufficient driving strength can be obtained.

Further, the diameter of the reinforcing roll that supports the entire rolling reaction force is set to φ1800 to 2000, which is the same as the diameter of the conventional roll.

Since the rolling reaction force is reduced by a factor of 30 to 40 as described above, sufficient strength can be obtained.

As described above, since the rolling load is reduced by reducing the diameter of the work rolls, a sufficient strength margin is obtained even if all the components of the rolling mill are of the conventional level, and safe operation is possible.

[Embodiments of the invention]

A six-high rolling mill, which is an embodiment of the present invention, will be described with reference to the drawings.

In FIG. 3, the stand 2 has three pairs of rolls, ie, work rolls 43 and 44, and an intermediate roll 4 movable in the roll axis direction.
6, 47, reinforcing rolls 41, 42 are built-in. This middle upper roll group is raised and lowered by a rolling down device 1.

The work rolls 43 , 44 are assisted by the spindle 10 . This drive is driven by a gear 11.19 provided after the spindle 10. In other words, as shown in FIGS. 3 to 5, the upper spindle is driven by a slave drive electric motor 23 via gears 11, 20, 21 and a coupling 22 by gear groups provided on both left and right sides of the spindle 10. Ru.

Similarly, the lower work roll 44 is connected to the universal coupling 1.
From 0 onwards, it is driven by a slave drive electric motor 27 via gears 19, 24, 25 and a coupling 26.

The aforementioned gear group is installed within the gear casing 12.

Further, the intermediate rolls 46, 47 are driven by a main drive motor 17, 18 connected via a universal coupling 8 and a slide coupling 9.

The approximate dimensions of each roll are as follows: Work roll 43, 4.4 has a diameter of 500 to 800 mm, body length 5200 mm, and intermediate roll 4.
6.47 has a diameter of 1000m, v trunk length 5200mm, reinforcing roll 41°42 has a diameter of 20001III + % trunk length 54!
About 200 cm is used. A hydraulic bending device 35 for applying benders is installed on the upper and lower work rolls 43, 44, and a hydraulic bending device 34 for applying benders is also installed on the upper and lower intermediate rolls 46, 47, and the intermediate rolls are moved in the axial direction. Shift device 4 to move
0 is engaged.

In addition, like the small-diameter work roll of the present invention and the 4-roll drive 6-high rolling mill, the diameter of the work roll is 30 to 4 compared to the conventional 4-high rolling mill.
If the work roll is made smaller by about 0, the deflection of the work roll becomes easier to deform in proportion to the fourth power of the roll diameter, so the deformation curve of the work roll changes greatly in response to changes in rolling load or sheet width, and the rolled sheet changes. The problem is that the cross-sectional profile changes.

Therefore, the main drive intermediate roll 46 newly added in the present invention,
47 can be moved left and right in the direction of the roll axis symmetrically with respect to the center of the rolled material 45 as shown by the arrows in FIG. However, sufficient control of the plate cross-sectional shape becomes possible, and the performance of the rolling mill of the present invention can be further improved.

In addition, the slave drive work rolls 43 and 44 and the main drive intermediate roll 4
The driving method of 6.47 is as follows.

That is, from the start to the end of the biting of the rolled material 45 into the roll, at least the circumferential speeds of both the work roll and the intermediate roll are driven to be synchronized. However, the drive torque of the slave drive work roll is kept within a transmittable range due to its strength.

Therefore, if the diameter of the work rolls 43, 44 is reduced to about 70% of the conventional diameter (φ1000→φ700), the allowable torque of the reduced diameter work roll will be approximately 0.0% of the roll diameter reduction ratio.
Since it is proportional to the cube of 7, the allowable transmission torque is 34
%, if the rolling speed is the same, the motor capacity per roll is the square of the roll diameter, which is 2 compared to the conventional 5000KW.
A small capacity device of about 450 KW (49 inches) can be installed, and if combined with the slip limit power of the intermediate roll drive, sufficient board biting rolling power can be produced (as mentioned above, the biting insufficient energy, that is, the power is 15-30 cm)
.

Of course, if the drive of the work rolls is continued even after the plate has been sufficiently bitten by the work rolls, the main drive power of the intermediate rolls can be added up, and sufficient rolling power can be applied to the rolled material. High pressure rolling becomes possible. In this case, the drive of the work rolls may be changed to constant torque control instead of speed control.

That is, in the past, when rolling a material with a deformation resistance close to 30Kf/m'' at a rolling temperature of about 750C, the permissible reduction amount per roll was about 2 to 3 degrees, but with the rolling mill of the present invention, In particular, due to the effect of reducing the rolling reaction force, it is now possible to perform reduction rolling that is approximately twice as much as conventional methods, making it possible to significantly shorten the rolling time, and making it possible to manufacture rolled steel materials with sufficiently improved low-temperature brittleness through low-temperature rolling. It becomes possible.

〔Effect of the invention〕

According to the present invention, it is possible not only to perform rolling with reduced rolling reaction force, but also to prevent the slip phenomenon between the work roll and its supporting roll, and to provide sufficient rolling power for biting into the roll. This has the effect of realizing a multi-high rolling mill.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram illustrating the situation in which it is necessary to bite the rolled material into the work rolls, Fig. 2 is an explanatory diagram illustrating the energy necessary for plate biting in the rolling mill shown in Fig. 1, and Fig. 3 4 is a schematic configuration diagram showing a 6-high rolling mill with a 40-level drive system, which is an embodiment of the present invention, FIG. 4 is a partial view of the top view of FIG. 3, and FIG.
The figure is a sectional view taken along the line AA in FIG. 3. 2...Housing, 43.44...Work roll, 4
6゜47...Intermediate roll, 41.42...Reinforcement roll, 8゜10...Universal coupling, 9...
・Slide coupling, 14.16...shaft, 17.
18... Main drive motor, 11, 19, 20, 21, 2
4゜25...gear, 22.26...coupling,
23゜躬 1 z 1 vine? 2 Approvalφ

Claims (1)

[Claims] 1. A pair of small-diameter work rolls is configured to be a secondary drive, this work roll is supported, and an intermediate roll that is a support roll with a larger diameter than the work roll is configured to be a main drive, and the arrangement of the rolls is arranged such that the pair of rolls is 1. A multi-high rolling mill comprising: a secondary driven small diameter work roll, a pair of main driving intermediate rolls, and a pair of reinforcing rolls that support the rolling load.