CN201632479U - Passage of Rollers in Rail Billet Rolling Mills - Google Patents

Abstract

The utility model relates to a pass of a steel rail breaking-down mill roller. The inclination of the outer lateral wall of a rail head of the pass of the roller of a steel rail breaking-down mill is larger than that of the inner lateral wall of the rail head; the inclination of the outer lateral wall of the rail head ranges from 20% to 30%; and the inclination of the inner lateral wall of the rail head ranges from 2% to 4%. The design of the pass of the steel rail breaking-down mill roller has the advantages of substantially reducing the single-pass turning amount of the roller, simultaneously being capable of ensuring constant metal amount at the rail head and the rail bottom of a rolled piece conveyed to a universal area after each time of turning, and facilitating straight control for steel tapping of frames in the universal area.

Description

Passage of the Rolls in the Rail Billet Rolling Mill

technical field

The utility model relates to rail rolling, in particular, the utility model relates to a roll pass of a rail blanking mill.

Background technique

Usually, the universal production line has seven rolling mills, including two blanking mills (BD1, BD2), three universal rolling mills (U1, U2, UF), and two edgers (E1, E2). layout.

The rails are rolled by the universal method in the universal production line. Among the two billet rolling mills, the first billet rolling mill BD1 is equipped with 4 pass types: two box-shaped holes, one trapezoidal hole, and one hat-shaped hole, with a total of 5 passes or 7 passes; The second blanking mill BD2 is equipped with 3 kinds of rail-shaped holes, see Figure 1, each rolling 1 pass, a total of 3 rolling passes. The rolling mill BD2 adopts the direct rolling pass system, and the roll pass is as follows: the slope of the side wall of the rail head and the side wall of the rail bottom are both 2-4%. According to rail production experience, after a single rolling of several thousand tons of rails, the wear of the rail head and rail bottom sidewall of the roll pass is about 2mm. Therefore, the rolls must be turned off-line to ensure rolling accuracy. Generally speaking , a single turning of 100mm (that is, turning the roll to reduce its diameter by 100mm) can completely restore the pass design size, and the maximum allowable turning amount of a set of rolls is 150mm, so a set of rolls will be scrapped after only two uses. In this way, the production cost per ton of steel is as high as 100 yuan only for the roll consumption of the rolling mill BD2.

In order to increase the number of times the roll is used and reduce the production cost, when the roll is turned, the roll pass is allowed to be quantitatively widened. Usually, when the roll is turned, the way of widening the pass is to widen the two parts of the rail head and the bottom of the rail, but the rail waist is not widened, see Figure 2, but the disadvantage of this widening method is that each time the roll is turned Finally, the amount of metal in the two parts of the rail head and the rail bottom of the formed pass changes, causing the steel racks in the universal area to bend, causing product defects and equipment accidents such as rolling scars and crashing devices, and affecting the smooth production.

Utility model content

The utility model intends to solve the technical problem that the consumption of rolls of the second billet mill BD2 can be greatly reduced, and the steel tapping of each rack in the universal area can be guaranteed to be straight.

In order to solve the above-mentioned technical problems, the utility model provides a pass design of a rail billeting mill. The roll pass of the rail billeting mill is as follows: the rail waist of the rail billeting mill roll adopts a variable width design, That is, the rail waist width is designed according to the wear condition of each pass.

According to the utility model, the inclination of the outer side wall of the rail head of the pass of the roll of the rail blanking mill is greater than the inclination of the inner side wall of the rail head.

According to the utility model, the side wall of the rail head adopts a double-slope design, that is, the slope of the outer side wall of the rail head is not equal to the slope of the inner side wall of the rail head. According to the preferred solution of the present invention, the slope of the outer wall of the rail head is 20-30%, and the slope of the inner wall of the rail head is 2-4%.

In order to better solve the above technical problems, according to the utility model, the rail height of the roll pass after turning is equal to the sum of the rail height of the roll pass before turning and the width of the rail waist.

The width of the rail waist is 2mm.

The rail waist expansion is divided into the rail waist expansion near the bottom side of the rail and the rail waist expansion near the rail head side, and the rail waist expansion near the rail bottom side is greater than the rail waist expansion near the rail head side.

The rail waist expansion near the bottom side of the rail is 1.2mm, and the rail waist expansion near the rail head side is 0.8mm.

The advantage of the rail blanking mill according to the utility model is that the utility model can greatly reduce the consumption of BD2 rolls, and can ensure that the metal quantity of the rolled piece rail head and rail bottom sent to the universal area is constant, which is beneficial to all machines in the universal area. Frame tapping straight control.

Description of drawings

Figure 1 shows the roll pass configuration of the rail billet rolling mill;

Fig. 2 has shown the sketch map that the roll pass of the rail blanking mill is widened at the rail head and rail bottom according to the traditional technology;

Fig. 3 has shown the schematic diagram that the roll pass of the rail blanking mill according to the utility model is widened by the rail waist;

Fig. 4 has shown the inclination design at the roll pass rail head of the rail billet rolling mill according to the present utility model;

Fig. 5 shows the state before the roll pass of the rail blanking mill according to the utility model is widened by the rail waist;

Fig. 6 shows the state after the roll pass of the rail billet rolling mill is widened according to the utility model.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

On the universal production line for profile rolling, the first billet rolling mill BD1 and the second billet rolling mill BD2 are arranged in sequence to rough-roll the steel entering the production line.

As shown in FIG. 1 , three types of rail-shaped holes, ie, a rail-shaped deep-cut hole 1 , a rail-shaped extension hole 2 , and a pilot hole 3 , are arranged in the billet rolling mill BD2 . The rail is rolled step by step through the rail-shaped deep cut hole, the rail-shaped extended hole and the pilot hole.

When rolling, for example, several thousand tons of steel at a time, the roll pass of the blooming mill BD2 wears out afterwards. At this time, billet rolling mill BD2 must go offline for turning to restore its roll pass. According to the utility model, the rolls of the blanking mill BD2 are turned by only widening the rail waist without widening the two parts of the rail head and the rail bottom, as shown in FIG. 3 . The solid line in Figure 3 represents the state before the roll pass is widened, and the dotted line in Figure 3 represents the state after the roll pass is widened. As shown in the dotted line in Figure 3, when the rail waist After widening, the rail head and rail bottom also extend to both sides due to the widening of the rail waist. This widening method can not only greatly reduce the consumption of rolls, but also ensure the straightness of each rack in the universal area.

After rolling the steel, the roll pass of the blooming stand BD2 is worn due to use. When the amount of wear reaches a certain amount, the blanking mill BD2 must be turned off-line to restore its roll pass, so as to ensure the rolling effect. Every time the roll is turned, the amount of metal in the two parts of the rail head and the rail bottom of the formed pass changes, resulting in the bending of the steel when the rolled roll is used for steel rolling.

Therefore, the utility model proposes to improve the slope of the side wall at the rail head of the roll pass.

The slope of the side wall of the pass is the degree to which the side wall of the pass is inclined. Whether it is an open pass or a closed pass, the side wall of the pass is not perpendicular to the axis of the roll in any case, but has a certain angle with the vertical plane of the roll axis, that is, the slope of the side wall. There are three ways to express the slope of the side wall of the pass: (1) Expressed by percentage (%); (2) Expressed by the tangent of the angle between the pass side wall and the vertical line of the roll axis; (3) Expressed by The angle between the pass side wall and the vertical plane of the roll axis is directly expressed. In the present invention, the slope is represented by a percentage.

The slope of the pass side wall has the following effects:

(1) The original rolling groove width can be restored after the pass is worn. The pass without side wall slope cannot restore the original rolling groove width after the side wall is worn, while the pass with the side wall slope can restore the original rolling groove width after the side wall is worn and heavy.

(2) Make it easy for the rolled piece to enter the pass shape correctly. The inclined side wall makes the rolling groove form a bell mouth. When the rolled piece is fed into the pass, it can be automatically aligned and enter the pass smoothly. Align the center of the hole pattern.

(3) Make the rolled piece easy to get out of the groove, and reduce the accident of roll winding. If the side wall of the pass is perpendicular to the axis of the roll, after the rolled piece enters the pass, it will be tightly clamped by the side wall of the pass due to the wide spread, making it difficult to de-groove the rolled piece. It may even cause roll winding and roll breaking accidents. In this way, if the side wall of the pass has a slope, the clamping effect of the side wall of the pass on the rolled piece can be reduced, making it easy for the rolled piece to fall out of the groove.

(4) When the roll is reloaded, the amount of turning can be reduced and the service life of the roll can be extended. The slope of the side wall of the pass is different, and the amount of heavy vehicles necessary to restore the original shape of the rolling groove is also different. When the amount of wear is constant, the greater the slope of the side wall of the pass, the smaller the amount of turning, on the contrary, the smaller the slope of the side wall of the pass, the greater the amount of turning.

Therefore, the pass type with a large sidewall slope is of great significance to reduce the heavy load of the roll, reduce the consumption of the roll, and improve the service life of the roll. The slope of the side wall of the pass pattern depends on the use of the pass pattern and the deviation requirements of the finished product (referring to the finished pass pattern) and other factors. In general, in order to save rolls and improve the working conditions of the rolling mill, it is hoped that the slope of the side wall of the pass is as large as possible. However, the slope of the side wall should not be too large, otherwise the rolled piece is easy to twist, and the cross-sectional shape is not easy to guarantee. However, the small slope of the side wall is conducive to clamping the rolled piece, making the rolled piece stable in the pass, and the side of the rolled piece is well processed.

The slope value of the pass side wall can be determined according to production experience.

Traditionally, the slope of the side wall of the rail head of the pass type is usually a certain value, and does not change due to the position of the side wall. In this way, for some pass types with small sidewall slopes, when the roll pass is worn and the roll needs to be turned, it usually leads to the pass formed by the turned roll in the lock part (that is, from the pass The width of the overlapping portion of the side walls of the two rolls extending from the profile) is greater than the design value.

The utility model improves the slope design of the rail head side wall of the pass type.

As shown in Fig. 4, according to the utility model, a double-slope design is adopted for the rail head side wall of the rail-shaped deep-cut hole 1 and/or the rail-shaped extension hole 2 of the rolling mill BD2. Specifically, the roller rail-shaped deep-cutting hole 1 and/or rail-shaped extension hole 2 are designed so that the slope of the outer wall of the rail head is greater than the slope of the inner wall of the rail head. Here, the outer wall of the rail head refers to the outside of the pass profile. That part of the sidewall, that is, the part of the sidewall that overlaps between the two rolls, is indicated by x in Figure 4, and the inner sidewall of the rail head refers to the sidewall of the rail head part within the pass profile, indicated by the x in Figure 4 y indicates.

The preferred scheme given by the utility model is that the slope x of the outer side wall of the rail head is 20-30%, and the slope y of the inner side wall of the rail head is 2-4%.

After the steel is rolled, the rolls of the rolling mill BD2 are worn, resulting in deformation of the roll pass. Therefore, the rolling mill BD2 needs to be turned to ensure the product quality after rough rolling. When rolling mill BD2 is turned, determine the turning widening amount of rail waist according to the wearing and tearing situation of each roll pass, according to billet rolling mill BD2 of the present utility model, when its rail waist widening is 2mm, the single turning amount of rolling mill BD2 roll is 20mm, therefore, compared with the single turning amount of the traditional BD2 roll, the single turning amount of the billet mill BD2 according to the utility model is greatly reduced, which is 20% of the traditional BD2 roll single turning amount.

After each turning, the rail height of the roll pass (that is, the distance between the rail bottom and the rail head) changes. According to the utility model, the roll pass rail height after turning is equal to the roll pass rail height and the rail height before turning. The sum of waist extension and width. Specifically, as shown in Figure 5 and Figure 6, the height of the roll pass after turning is h2, the height of the roll pass before turning is h1, and the rail waist expansion is divided into the rail waist expansion near the bottom side of the rail The amount a and the rail waist expansion amount b near the rail head side, therefore, according to the utility model, h2=h1+a+b, wherein, the values of a and b are determined according to the wear conditions of the rail head and the rail bottom side wall, Generally, a takes 1.2mm, b takes 0.8mm, and a+b=2mm.

According to the design that the slope of the outer side wall of the rail head is greater than that of the inner side wall of the rail head, it is possible to avoid the excessive width of the rail head locking part of the roll pass that is widened after the roll is turned, thereby further ensuring the universal area Each frame taps steel straight.

Although some exemplary embodiments of the general inventive concept have been shown and described, those skilled in the art should understand that these exemplary embodiments can be modified without departing from the principle and spirit of the general inventive concept of the present utility model. Instead, the scope of the general inventive concept is defined by the claims and their equivalents.

Industrial applicability

The billet rolling mill BD2 according to the utility model is put into use. After rolling 8,000 tons of 60kg/m rail once, the rolls of the billet rolling mill BD2 are rolled off the assembly line for turning, and the width of the rail waist is designed to be 2mm. 20mm, compared with the traditional blooming mill BD2, the amount of turning is greatly reduced, so the service life of the roll is increased, and the production cost is reduced.

Claims (2)

1. a rail big mill roll Pass is characterized in that, the rail head lateral wall gradient of the roll Pass of this rail big mill is greater than rail head madial wall gradient.

2. pass as claimed in claim 1 is characterized in that: rail head lateral wall gradient is 20-30%, and rail head madial wall gradient is 2-4%.

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