JPH0347924B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a leveler mill.

A leveler mill is a rolling mill that adds a rolling function to a normal leveler to flatten a steel strip.
In conventional leveler mills, rolling is performed with tension applied even in the final stage, so warpage (mainly warpage in the longitudinal direction, but also warpage in the width direction may occur) occurs in the final roll, which can lead to warpage in the next process. This will cause problems when passing the board through the board. Particularly, in the case of thick steel strips, the warpage in the width direction becomes so large that it cannot be ignored.

Leveler mills have rolls arranged in a staggered manner, making it difficult to install effective roll bending equipment. Therefore, even if hard reduction rolling is attempted in a leveler mill, the shape of the rolled material deteriorates due to roll deflection, the rolling speed is kept low, and efficiency is not improved.

Therefore, an object of the present invention is to provide a reinforced lower leveler.
To obtain a leveler mill capable of correcting warpage of rolled material in the mill.

The leveler mill of the present invention uses a variable crown roll to compensate for roll deflection if necessary, and performs normal leveling on the exit side of the leveler mill to correct warping of the rolled material.

First, the variable crown roll (hereinafter simply referred to as VC roll) used in the leveler mill of the present invention.
will be briefly explained with reference to FIG. 1A.
This VC roll has an annular space 3 between the arbor 1 and the sleeve 2, and a high-pressure medium (for example, water, oil, grease, etc.) and adjusts the pressure of the medium by means of a unit 4 to control the amount of crowning of the roll (the amount of expansion of the roll in the radial direction). If necessary, the pressure receiving chamber 3 may be divided into a plurality of parts as shown in FIGS. 1B and 1C.

FIG. 2 shows the roll arrangement of the leveler mill of the present invention. In order to correct the warping of the rolled material, rolling was not performed between the upper and lower final rolls No. 5 and No. 6.
Perform normal leveling. To this end, either the upper and lower adjacent roll spacings are equal (l ₁ = l ₂ = l ₃ ) and the final roll spacing (l ₄ ) is maximized, or the final roll spacing (l 4 ) is unequal (l ₁ ≠ l ₂ ≠ l ₃ ), the final roll interval (l ₄ ) is maximized, and the upper and lower final rolls No.5 and No.6
Adjust the reduction amount between.

Since the warp correction of the rolled material by the final rolls No. 5 and No. 6 is not necessarily sufficient, the warp correction can be completed by installing a straightening roll unit 40 after roll No. 6.

Representative examples of leveler mills to which the present invention is applied are shown in FIGS. 3 and 4. The leveler mill shown in Fig. 3 consists of five upper work rolls 11 and four lower work rolls 12, each work roll 1
A plurality of small diameter backup rolls 21 are arranged at 1 and 12. As mentioned above, the final roll interval is maximized, and the backup roll 2 is used for the upper and lower final work rolls 11 and 12.
The number of 1 is smaller than the others (in this embodiment, it is reduced from 3 to 2).

The upper and lower work rolls 11 and 12 are supported by a housing (not shown) so as to be driven independently, and each set of upper and lower backup rolls 21 is supported by a housing 22 (FIG. 5). Ru. The housing 22 is provided with a lowering device (not shown). Work roll 11,1
By driving the back-up roll 2, the back-up roll rotates, and a roll bite 31 is formed by a rolling down device provided in the housing 22 of the back-up roll 21.

In the present invention, a part of the work roll is made into a VC roll in order to compensate for roll deflection due to strong pressure. Ideally, the VC roll should be applied to all rolls, but it can also be effective if applied only to positions where roll deflection is large. In this embodiment, the first and second work rolls on the upper side and the first work roll on the lower side
Make the roll a VC roll (the shaded roll in the drawing is a VC roll).

The leveler mill shown in FIG. 4 is composed of four work rolls 11 each on the upper and lower sides and a backup roll 21a having a large diameter for each work roll 11. The upper and lower first and second backup rolls 21a (shaded rolls) are VC rolls, and strong reduction rolling is performed here. The upper and lower exit side backup rolls 21a perform rolling adjustment to correct longitudinal warping of the rolled material. As mentioned above, the roll spacing of the final roll is maximized. Since the two upper and lower work rolls on the exit side are used only for leveling, the backup roll 21a may be omitted.

A straightening roll unit 40 is further provided on the exit side of the leveler mill to straighten warpage in the width direction of the rolled material.

FIG. 5 shows a control system for the leveler mill of the present invention. The leveler mill in this example is the third leveler mill.
Use the leveler roll shown in the diagram. Bridle rolls 51 and 52 are provided on the mill entry and exit sides, respectively, and thickness gauges 53 and 54 are provided on the entry and exit sides of these rolls.

The detection signal from the thickness gauge 53 installed on the inlet side of the mill is sent to the housing 22 on the inlet side to perform feed forward control, and the detection signal from the thickness gauge 54 installed on the outlet side of the mill is sent to the housing 22 on the outlet side. 22 for feedback control. Outside of this,
Simultaneously with the feed forward control of the entry side housing 22, the crown of the VC roll used as the entry side work roll is controlled.

EXAMPLE A leveler mill shown in FIG. 3 was used to roll a pickled strip after hot rolling.

Work roll diameter: 380mm Backup roll diameter: 80mm Straightening roll unit: Large diameter 250mm Small diameter 60mm Mill exit side threading speed: 950m/min Lubricating oil: Soluble oil Strip: Thickness 3.8mm x width 1000mm Roll drive is at the bottom Only the side rolls are controlled to gradually increase their speed using a DC motor, and the two rolls on the exit side are used to adjust the rolling reduction, and a non-driven strong straightening roll unit 40 is further installed on the exit side of the leveler mill to correct warping. . In addition, strong reduction rolling was performed using three VC rolls on the entry side.

It was possible to roll the material to a thickness of 0.19 mm in one pass, and achieve a rolling reduction of 95%. The shape and edge surface quality of the finished product were as good as those of a conventional rolling mill, and warping defects were also sufficiently improved.

Example 2 A pickled strip after hot rolling was rolled using the leveler mill shown in FIG.

Work roll diameter: 350mm Backup roll diameter: 450mm Straightening roll unit: Large diameter 200mm Small diameter 80mm Mill exit side threading speed: 200m/min Lubricating oil: Soluble oil Strip: Thickness 3.2mm x width 914mm Roll drive is Gradual speed increase control was applied to the six work rolls on the side, the two work rolls on the output side and the straightening roll unit were not driven, and the warp was corrected by adjusting the rolling reduction.

It was rolled to a thickness of 0.6 mm in one pass rolling. The shape of the finished product was good and there were no warpage defects.

The leveler mill of the present invention is a relatively small piece of equipment, is capable of strong rolling reduction of 90% or more, can obtain products of stable high quality, and has high productivity.

[Brief explanation of drawings]

Figure 1 shows the VC used in the leveler mill of the present invention.
FIG. 2 is a longitudinal sectional view of a half body of a roll. FIG. 2 is an explanatory diagram showing the roll arrangement of the leveler mill of the present invention. FIG. 3 is an explanatory diagram showing an example of the structure of the leveler mill of the present invention. Fourth
The figure is an explanatory diagram showing another configuration example of the leveler mill of the present invention. FIG. 5 is an explanatory diagram showing the control system of the leveler mill shown in FIG. 3. 11, 12: Work roll, 21, 21a:
Backup Roll, 20: Housing, 4
0: straightening roll unit, 51, 52: bridle roll, 53, 54: thickness gauge.

Claims (1)

[Scope of Claims] 1. A plurality of work rolls are arranged in a staggered manner vertically, and a roll bite is formed between each of the upper and lower rolls, excluding the downstream side of two or three rolls from the exit side, and A leveler characterized in that at least one back-up roll is arranged around each roll, a lowering device is provided in each housing of the back-up roll, and a straightening roll unit is provided on the exit side of the final roll. ·mill. 2. The leveler mill according to claim 1, wherein at least one of the work roll and the backup roll is comprised of a variable crown roll.