A large-arc flat-box elliptical pass system for a bar production line

Abstract

The application discloses a large-arc flat-box elliptical hole system for a bar production line, which comprises a large-arc flat-box hole, an elliptical hole and a round hole. The large-arc flat-box elliptical hole is used for smoothly transitioning the profile of a rolled piece, and the rolled piece is shaped in advance before entering the round hole. The rolled piece is gradually shaped through the elliptical hole, and the cross-sectional area is reduced, thereby prolonging the length of the rolled piece. The cross-sectional shape of the rolled piece is changed through the round hole, and the quality and precision of the bar are improved. According to the technical scheme of the application, the material profile is arc-shaped on both sides after being rolled by the large-arc flat-box elliptical hole and the elliptical hole, the cross section is reduced, the temperature drop of the corner part is reduced, the wear of the rolling groove is reduced, the fullness of the hole is improved, the rolling piece torsion accident is reduced, the surface flatness problem of the round steel is eliminated, the rolled piece basically cannot produce the surface flatness defect after entering the finished product hole, the surface flatness defect of the final product is eliminated, and the grinding cost of the finishing process is reduced.

Description

Technical Field

[0001] This invention relates to the field of profiled tube rolling technology, and more particularly to a large arc flat box elliptical die system for bar production lines. Background Technology

[0002] Currently, in the production of round steel from section steel rolling, there are several pass systems: square hole + elliptical hole + round hole, round hole + elliptical hole + round hole, elliptical + vertical elliptical + elliptical + round hole, and square hole + flat + vertical elliptical + elliptical + round hole. The book "Pass Design" by Bai Guangrun, Luan Guifu, and Zhu Dianqiang provides a detailed explanation of each pass system. The square hole + elliptical hole + round hole system is characterized by large elongation and stable rolling, but the corners of the square workpiece are prone to folding defects when entering the elliptical hole. Due to the small amount of metal deformation, planar defects are easily generated on the surface of the round steel, resulting in poor product precision. The round hole + elliptical + round hole system is characterized by high dimensional accuracy and high out-of-roundness accuracy of the round steel products, stable rolling, and low wear on the finished product groove. However, the pass system has poor commonality, requires round billets, places high demands on the working conditions of the rolling line, and the iron oxide scale on the surface of the rolled workpiece is not easy to remove, affecting the surface quality of the product. The elliptical + vertical elliptical + elliptical + round hole system features high dimensional accuracy and out-of-roundness precision in round steel products, stable rolling, and minimal wear on the finished product's rolling groove. However, it is difficult for the billet to bite into the elliptical hole, making it virtually impossible to produce larger sizes. The square hole + flat hole + vertical elliptical hole + elliptical hole + round hole system offers high versatility and saves on roll consumption, but the rolling process is unstable. Summary of the Invention

[0003] To address the aforementioned technical problem of unstable rolling during the production process of various pass types, this invention provides a large-arc flat box elliptical pass system for bar production lines. This invention primarily achieves smooth transitions between different rolling mills by using a pass type combination of large-arc flat box elliptical passes, elliptical passes, and round passes, thus completing the production of round steel. This reduces the cross-sectional area, thereby minimizing corner temperature drop and groove wear, improving pass filling, reducing torsion accidents in rolled pieces, and eliminating flatness issues on the round steel surface.

[0004] The technical means employed in this invention are as follows:

[0005] A large arc flat box elliptical hole system for a bar production line includes: a large arc flat box hole, an elliptical hole, and a round hole;

[0006] The rolled piece undergoes a smooth transition through the elliptical hole of the large arc flat box, which pre-shapes the rolled piece before it enters the circular hole.

[0007] The rolled piece is gradually shaped through the elliptical hole, and the cross-sectional area is reduced, thereby extending the length of the rolled piece;

[0008] The shape of the rolled piece cross-section is changed by passing it through the circular hole, thereby improving the quality and precision of the bar stock.

[0009] Furthermore, the large circular arc flat box elliptical hole is set in the first process and includes a large circular arc, a large circular arc transition arc, and a side wall. The large circular arc is the hole wall on both sides of the large circular arc flat box elliptical hole, the side wall is the hole wall on the upper and lower sides of the large circular arc flat box elliptical hole, and the large circular arc transition arc is the arc of the transition section between the large circular arc and the side wall.

[0010] Furthermore, the elliptical hole is set in the second process, which gradually deforms the rolled piece through the elliptical hole of the large arc flat box into a rolled piece that is close to a circle, and uniformly disperses stress by reducing the cross-sectional area, thus avoiding local stress concentration.

[0011] Furthermore, the circular hole is set in the third process to change the cross-section of the rolled piece into a circular cross-section, thereby reducing the diameter deviation of the rolled piece and improving its roundness.

[0012] Furthermore, by using the large arc flat box elliptical hole in conjunction with the elliptical hole, the material profiles between each rolling mill can be smoothly transitioned, completing the production of round steel, reducing the cross-section, thereby reducing the temperature drop at the corners and the wear of the rolling groove, improving the filling degree of the profile, reducing the torsion accident of the rolled piece, and eliminating the flatness problem on the surface of the round steel.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The present invention provides a large arc flat box elliptical die system for bar production line, which, compared with conventional die types, can reduce the consumption of rolls and reduce maintenance costs.

[0015] 2. The present invention provides a large arc flat box elliptical die system for bar production line. After rolling by the large arc flat box elliptical die + elliptical die, the two sides of the material are arc-shaped. After entering the finished product hole, it can basically not produce planar defects. Finally, the planar defects on the surface of the finished product are eliminated, reducing the grinding cost of the finishing process.

[0016] 3. The present invention provides a large arc flat box elliptical pass system for bar production line, which allows for smooth transition of material profiles between rolling mills, completes the production of round steel, reduces cross-section, reduces corner temperature drop and groove wear, improves pass filling, reduces torsion accidents of rolled parts, and eliminates flatness problems on the surface of round steel.

[0017] Based on the above reasons, this invention can be widely promoted in the field of profiled tube rolling technology. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the process hole type of the large arc flat box elliptical hole type system for a bar production line according to the present invention;

[0020] Figure 2 This is a schematic diagram of the elliptical hole type of the large arc flat box for a bar production line according to the present invention.

[0021] In the diagram: 1. Large circular arc; 2. Large circular arc transition arc; 3. Side wall. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0026] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0027] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0028] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0029] like Figures 1 to 2As shown, the present invention provides a large arc flat box elliptical hole system for bar production line, including: large arc flat box hole, elliptical hole, and round hole;

[0030] The rolled piece undergoes a smooth transition through the elliptical hole of the large arc flat box, which pre-shapes the rolled piece before it enters the circular hole.

[0031] The rolled piece is gradually shaped through the elliptical hole, and the cross-sectional area is reduced, thereby extending the length of the rolled piece;

[0032] The shape of the rolled piece cross-section is changed by passing it through the circular hole, thereby improving the quality and precision of the bar stock.

[0033] Furthermore, the large circular arc flat box elliptical hole is set in the first process and includes a large circular arc, a large circular arc transition arc, and a side wall. The large circular arc is the hole wall on both sides of the large circular arc flat box elliptical hole, the side wall is the hole wall on the upper and lower sides of the large circular arc flat box elliptical hole, and the large circular arc transition arc is the arc of the transition section between the large circular arc and the side wall.

[0034] Furthermore, to produce Ф300mm round steel, a special-shaped material with a height of 317mm, a width of 324.9mm, and an arc radius of R450mm can be rolled using a large arc flat box elliptical die. The design of the special large arc flat box elliptical die is shown in the figure, and according to the Wusatoski formula, it is as follows:

[0035] β=(h0 / h1)W*K

[0036] Where β is the ratio of the width of the rolled piece before entering the pass to the width of the rolled piece after exiting the pass; W = 10 - 1.269 * δw0.566 * δw, where δw0.566 is the factor affecting the roll diameter; δw is the factor affecting the pass shape; K = steel temperature influence coefficient × rolling speed influence coefficient × steel grade influence coefficient × roll material and surface finish influence coefficient, the coefficients are different under different working conditions; for round rolled pieces in square holes, δw = 1.012-1.013, and for square rolled pieces in square holes, δw = 1.00-1.011. The relevant parameters are calculated as shown in the table below:

[0037]

[0038] Furthermore, the elliptical hole is set in the second process, which gradually deforms the rolled piece through the elliptical hole of the large arc flat box into a rolled piece that is close to a circle, and uniformly disperses stress by reducing the cross-sectional area, thus avoiding local stress concentration.

[0039] Furthermore, the circular hole is set in the third process to change the cross-section of the rolled piece into a circular cross-section, thereby reducing the diameter deviation of the rolled piece and improving its roundness.

[0040] Furthermore, by using the large arc flat box elliptical hole in conjunction with the elliptical hole, the material profiles between each rolling mill can be smoothly transitioned, completing the production of round steel, reducing the cross-section, thereby reducing the temperature drop at the corners and the wear of the rolling groove, improving the filling degree of the profile, reducing the torsion accident of the rolled piece, and eliminating the flatness problem on the surface of the round steel.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A large arc flat box elliptical hole type system for a bar production line, characterized in that, include: large circle Arc-shaped flat box hole, elliptical hole, round hole; The rolled piece undergoes a smooth transition through the elliptical hole of the large arc flat box, which pre-shapes the rolled piece before it enters the circular hole. The rolled piece is gradually shaped through the elliptical hole, and the cross-sectional area is reduced, thereby extending the length of the rolled piece; The shape of the rolled piece's cross-section is changed by passing through the circular hole, thereby improving the quality and precision of the bar stock; The large circular arc flat box elliptical hole is set in the first process and includes a large circular arc, a large circular arc transition arc, and a side wall. The large circular arc is the hole wall on both sides of the large circular arc flat box elliptical hole, the side wall is the hole wall on the upper and lower sides of the large circular arc flat box elliptical hole, and the large circular arc transition arc is the arc of the transition section between the large circular arc and the side wall.

2. The large arc flat box elliptical hole type system for a bar production line according to claim 1, characterized in that: The elliptical hole is set in the second process, which gradually deforms the rolled piece that passes through the elliptical hole of the large arc flat box into a rolled piece that is close to a circle, and disperses the stress evenly by reducing the cross-sectional area, thus avoiding local stress concentration.

3. The large arc flat box elliptical hole type system for a bar production line according to claim 1, characterized in that: The circular hole is set in the third process to change the cross-section of the rolled piece into a circular cross-section, reduce the diameter deviation of the rolled piece, and improve its roundness.

4. The large arc flat box elliptical hole type system for a bar production line according to any one of claims 1, characterized in that: By using the large arc flat box elliptical hole in conjunction with the elliptical hole, the material profiles between rolling mills can be smoothly transitioned, completing the production of round steel, reducing the cross-section, thereby reducing corner temperature drop and groove wear, improving the filling degree of the profile, reducing torsion accidents of rolled pieces, and eliminating flatness problems on the surface of round steel.

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