JPS61296904A - Rolling mill - Google Patents

Abstract

PURPOSE:To considerably decrease skew force and thrust force by intersecting the crown of work rolls with the straight line parallel with a roll shaft point symmetrically at 3 points and making equal the area or diameter formed of the right and left curves of the origin. CONSTITUTION:The initial crown of the upper work roll 2 is given like curves Au, Bu, Cu, Du and Eu, is parallel with the roll shaft and intersects with the straight line XuL running the point symmetrical origin respectively at Bu and Du. The area formed by the straight line XuL and the initial crown or the absolute value of the volume taken by the entire outside diameter of the roll is made equal on the right and left. The skew force is thereby decreased to 1/20 the skew force of the conventional work roll and the thrust force is also decreased to 1/7 and therefore the mechanism for a roll bearing is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rolling mill for manufacturing steel plates, and more specifically, the present invention relates to a rolling mill for manufacturing steel plates, and more specifically, by controlling the thickness distribution of the rolled steel plates in the width direction, The present invention aims to provide a rolling mill that performs a rolling method for the purpose of improving shape control and improving production efficiency by varying the number of rolling passes.

(Prior art) In the production of steel plates, methods for controlling the thickness distribution in the width direction of rolled steel plates include the roll shift method, roll cross method, and roll pen 7"4 puffer method (for example, the Japanese Iron and Steel Association “Theory and Practice of Plate Rolling JP, 103~
P, 110).

In particular, JP-A-56-30014, JP-A-58-18
The method proposed in Publication No. 7207 for relatively moving a roll provided with a five-point symmetrical roll curve in the axial direction is as follows:
This method is particularly advantageous in terms of equipment cost and control ability.

(Problems to be solved by the invention) JP-A-56-30014, JP-A-58-1872
Publication No. 07 is an excellent method in terms of sheet thickness distribution control in the sheet width direction, but due to the roll shape, during rolling or when adjusting the zero point of the roll gap, the horizontal plane A force that rotates the rolls (skew force) is generated within the shaft, causing the roll axes to become unable to remain parallel.

In this state, a force (thrust force) in the axial direction of the roll is generated. If the thrust force becomes excessive and pushes the mill motor through the spindle, accidents such as damage to the mill motor may occur, so excessive equipment is required to stop the thrust force from being received inside the rolling mill. Become.

JP-A-56-30014, JP-A-58-1872
In the combination of a work roll and a reinforcing roll or a work roll, an intermediate roll, and a reinforcing roll proposed in Publication No. 07,
A point-symmetrical initial crown is formed to fit on the surface of the rolls having opposite roll diameters, and a large amount of force is required for relative movement in the axial direction, resulting in complicated equipment.

Under such conditions, when the roll curves of the work roll and the reinforcement roll are changed, a locally large surface pressure distribution occurs between the work roll and the reinforcement roll. Locally large surface pressure is
Accelerates roll wear and adversely affects roll life.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides initial crowns of approximately the same shape to each of the upper work roll and the lower work roll so as to be symmetrical with respect to each other, so that the width of the material to be rolled is increased. A rolling mill that controls the crown of the rolled material rolled by the upper and lower work rolls by moving the upper and lower work rolls relative to each other in the axial direction according to changes in rolling conditions such as thickness and rolling load. , the initial crowns of the upper and lower cropping rolls intersect a straight line parallel to the roll axis and passing through the origin at three points symmetrically, and the initial crowns and the roll The gist of this rolling mill is that the absolute value of the area of the interval formed between the roll and the straight line parallel to the axis or the volume taken over the entire outer periphery of the roll is made equal.

(Operation) Based on FIG. 1, the results of experiments and studies conducted by the present inventors will be explained. In the figure, 1 is a plate material to be rolled, 2 is an upper work roll, and 3 is a lower work roll.

An initial crown of Au, Bu, Cu, Du, or Eu is applied to the outer peripheral surface of the upper work roll 2.

Here, the curve Au Bu Cu, the curve Cu Du I
A straight line X where u is parallel to the axis of the roll and passes through the origin of point symmetry
uL intersects with Bu and Du respectively, and the axis XuL
On the other hand, there is a negative value between Au and Bu, and a negative value between Bu and Cu
Between glass, Cu, minus between Bu, Du, Eu
Between the glass, the area of the distance between the axis Xu) and the initial crown or.

This allows the absolute value of the volume taken over the entire outer periphery of the roll to be formed equally.

Now, for example, the curves Au, Bu, Cu, Du
, Eu as y = a (XuL"-c"Xu4
．． ), then 1 becomes the curve Au Bu Cu Du E
It represents the imaging width of u, which governs the roll surface pressure, and represents the positions of points Bu and Du where the coefficient C intersects the axis XuL, which governs the skew force.

(Example) Roll length: 5.500 mm, roll diameter: 1,200 mm
Initial crowns shown in FIG. 1 were provided on the upper and lower work rolls of a rolling mill with a rolling reaction force of 10.00 Q rows, and reinforcing rolls were combined as shown in FIG. 2 for rolling.

The results are shown in Table 1 together with the conventional example.

Table 1 As shown in the table, in the example of the present invention, the thrust force was reduced to 13 inches, and the skew force was reduced by well over 5 degrees.

(Effect of the invention) The present invention relates to an initial crown of a work roll.

A straight line that is parallel to the roll axis and passes through the point-symmetrical origin intersects at three points including the origin, and the areas or volumes formed by both lines on the left and right sides of the origin are equal, so the ski force is 1.
/20, and since there is no cross state of the rolls, the thrust force is also reduced to 1/7, which simplifies the mechanism that supports the thrust force and fixes the rolls, and has a positive effect on the life of the mill motor. The effects brought about by this are great.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the initial crown of the work roll according to the first invention, FIG. 2 is an explanatory diagram of the combination of the work roll and reinforcing roll according to the second invention, and FIG. 3 is an explanatory diagram of the work according to the conventional example. FIG. 4 is an explanatory diagram of the initial crown of a roll, and FIG. 4 is an explanatory diagram of a combination of a work roll and a reinforcing roll according to a conventional example. 1... Material to be rolled 2... Upper work roll 3...
・Bottom work roll 4...Top reinforcing roll 5...Bottom reinforcing roll Fig. 3 Fig. 4: 1: Ki ■Ken roll

Claims (3)

[Claims] (1) Give initial crowns of approximately the same shape to each of the upper work roll and the lower work roll so that they are point symmetrical to each other,
According to changes in the rolling conditions such as the width, thickness, and rolling load of the material to be rolled, the upper and lower work rolls are moved relative to each other in the axial direction, and the crown of the material to be rolled is rolled by the upper and lower work rolls. In a rolling mill that controls the initial crowns of the upper and lower work rolls, the initial crowns of the upper and lower work rolls intersect a straight line parallel to the roll axis and passing through the origin at three points symmetrically, and the initial crowns are A rolling mill characterized in that the area of the interval formed between the crown and the straight line parallel to the roll axis or the absolute value of the volume taken over the entire outer periphery of the roll are made equal. (2) The initial crowns of the upper and lower reinforcing rolls facing the upper and lower work rolls are made into a zero crown or a convex crown to facilitate sliding during relative movement of the work rolls in the axial direction. , a rolling mill according to claim 1. (3) Claim 1 or 2 characterized in that a lubricant is dripped or applied to the portion where the surface pressure between the work roll and the reinforcing roll is strongest to reduce roll wear.
The rolling mill described in section.