Rolling round steel pass and design method

Abstract

The application provides a rolling round steel pass and a design method, the pass comprises a base circle and width expansion parts located on both sides of the base circle, wherein the width expansion part has an expansion section in the shape of a circular arc; the diameter of the base circle is referred to as the height hk of the pass, the height hk of the pass is 1.011-1.013 times the nominal diameter d of the round steel; the notch width Bk is greater than the height hk of the pass; the expansion circle where the expansion section is located is circumscribed to the base circle, and the other end of the expansion section is connected with the intersection of the notch line and the roll gap line. The rolling round steel pass does not excessively depend on the equipment precision, and the precision of three-roll rolling mill can be achieved by using two-roll rolling mill equipment, so that the contradiction between the quality and the investment is solved. The round steel is rolled by using the pass, the rolling quality is stable, the pass has high steel passing capacity, and the size precision is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rolling steel, in particular to a rolling round steel pass and a design method. BACKGROUND

[0002] At present, the bar production line mostly adopts a flat-stand alternating continuous rolling production line, and the main rolling mill is a short stress line two-roller rolling mill. In order to pursue higher rolling size precision, individual production lines adopt KOCSK, PSM and other three-roller reducing mill.

[0003] Generally speaking, the rolling precision of the three-roller rolling mill is higher than that of the two-roller rolling mill, but the three-roller rolling mill has a complex structure and is difficult to maintain. Most of them are expensive equipment, and it is more difficult to obtain corresponding drawings and spare parts. The short-term precision is good, but the precision will decrease over time. The quality of maintenance determines the speed of performance decline, and the two-roller rolling mill can make up for the gap in equipment performance through an excellent pass design method, so as to achieve the same level of rolling precision.

[0004] In the prior art, the round steel pass design method usually determines the size of the expansion circle through the experience of the designer, and then determines the notch. Since the value of the expansion circle is usually a range value, the pass designed by randomly selecting a value within the range may not meet the design precision requirement. The traditional round steel pass system design method seriously depends on the experience level of the pass designer, and it is difficult for a designer lacking experience to design a mature pass system at one time. SUMMARY

[0005] The purpose of the present application is to provide a rolling round steel pass and a design method. The round steel rolled by the rolling round steel pass has good ovality, which improves the precision of the rolled round steel.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] A rolling round steel pass, comprising a base circle and a width expansion part located on both sides of the base circle, wherein the width expansion part has an expansion segment in the form of a circular arc; the diameter of the base circle is referred to as the height hk of the pass, and the height hk of the pass is 1.011-1.013 times the nominal diameter d of the round steel; the notch width Bk is greater than the height hk of the pass; the expansion circle where the expansion segment is located is circumscribed to the base circle, and the other end of the expansion segment is connected with the intersection of the notch line and the roll gap line.

[0008] Further, in the above-mentioned rolling round steel pass, the expansion angle θ of the expansion segment is 15°-30°.

[0009] Further, in the above-mentioned rolling round steel pass, the roll gap S is 0.1 times the height hk of the pass.

[0010] Furthermore, in the above-mentioned rolled round steel die, the radius r of the outer fillet is 3 to 5 mm.

[0011] Furthermore, in the above-mentioned rolling round steel die, the nominal diameter of the round steel is 20mm to 130mm.

[0012] Furthermore, in the above-mentioned rolled round steel die, the expansion angle θ of the expansion section is 30°.

[0013] Furthermore, in the above-mentioned rolled round steel die, the slot width Bk is 1.01 times the height hk of the die.

[0014] Furthermore, in the above-mentioned rolling round steel die, the round steel is rolled using the die, and the ellipticity of the round steel with a nominal diameter less than or equal to 70 mm is ≤0.4 mm, and the ellipticity of the round steel with a nominal diameter greater than 70 mm is ≤0.6 mm.

[0015] On the other hand, a design method for the above-mentioned rolled round steel die is provided, which uses drawing software to construct the die, characterized by including the following steps:

[0016] Step 1) Calculate the values ​​of the die profile parameters, including die height hk, roll gap S, slot width Bk, expansion angle θ, and outer fillet radius r;

[0017] Step 2) Draw the base circle. Use drawing software to draw a base circle with a diameter equal to the hole height hk.

[0018] Step 3) Draw the roll gap. Offset the vertical center line of the base circle to the left and right by S / 2 to draw the roll gap line.

[0019] Step 4) Draw the groove line by shifting the horizontal center line of the base circle upwards and downwards by Bk / 2 to form the groove line;

[0020] Step 5) Draw the expansion angles. Rotate the horizontal center line of the base circle by θ in the counterclockwise and clockwise directions respectively, with the center of the base circle as the axis, to obtain two expansion angle lines.

[0021] Step 6) Draw the expansion segment. The starting point of the expansion segment is located at the intersection of the expansion angle line and the base circle, and the ending point of the expansion segment is located at the intersection of the groove line and the roll gap line, and the expansion segment is externally tangent to the base circle.

[0022] Step 7) Draw the outer fillet, mirror the expansion segment and complete the shape with the outer fillet, delete the redundant line segments of the shape, and keep the target shape.

[0023] Analysis reveals that this invention discloses a rolling pass for round steel and its design method. This rolling pass can be used for both finished round steel products and transition / extension passes, exhibiting strong adaptability. It can be used to produce bearing steel, gear steel, spring steel, carbon alloy steel, and some high-alloy steels. This rolling pass does not overly rely on equipment precision, and it achieves the precision of a three-roll mill even with a two-roll mill, resolving the conflict between quality and investment. Using this rolling pass results in stable rolling quality, strong throughput capacity, and high dimensional accuracy. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0025] Figure 1 This is a schematic diagram of drawing a base circle according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of drawing the roll gap according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of drawing the slot line according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of drawing the expansion angle according to an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of drawing an expansion segment according to an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of a structure according to an embodiment of the present invention.

[0031] Figure 7 This is a flowchart illustrating a design method according to an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached diagram: 1. Base circle; 2. Expansion section; 3. Outer fillet; 4. Roller seam line; 5. Groove line; 6. Expansion angle line. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. Indeed, those skilled in the art will recognize that modifications and variations can be made to the invention without departing from its scope or spirit. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the invention encompass such modifications and variations falling within the scope of the appended claims and their equivalents.

[0034] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected," "linked," and "set up" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection through intermediate components; a wired connection, a radio connection, or a wireless communication signal connection. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0035] The accompanying drawings illustrate one or more examples of the invention. The detailed description uses numerals and letters to refer to features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to refer to similar or analogous parts of the invention. As used herein, the terms “first,” “second,” and “third,” etc., are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.

[0036] like Figures 1 to 7 As shown, according to an embodiment of the present invention, a rolling round steel pass is provided, comprising a base circle 1 and width expansion portions located on both sides of the base circle 1, wherein the width expansion portions have arc-shaped expansion sections 2; the diameter of the base circle 1 is called the height hk of the pass, and the height hk of the pass is 1.011 to 1.013 times the nominal diameter d of the round steel, i.e., hk = (1.011 to 1.013) × d; the groove width Bk is greater than the height hk of the pass; the expansion circle where the expansion section 2 is located is externally tangent to the base circle 1, and the other end of the expansion section 2 is connected to the intersection of the groove line 5 and the roll gap line 4.

[0037] Furthermore, the expansion angle θ of the expansion segment 2 is between 15° and 30°. A smaller value for the expansion angle θ of the expansion segment 2 results in better ellipticity but worse commonality; a larger value results in worse ellipticity but better commonality. Preferably, the expansion angle θ of the expansion segment 2 is 30°.

[0038] Furthermore, the roll gap S is 0.1 times the height hk of the roll pass, i.e., S = 0.1 × hk. The roll gap S is generally related to the mill bounce, the thermal expansion of the rolls, and the deflection caused by the rolls under stress. Setting the above parameters of the roll gap S can avoid rolling defects caused by the adhesion of the upper and lower rolls due to the wear of the roll pass during the rolling process. At the same time, an appropriate roll gap can improve the ellipticity of the rolled round steel.

[0039] Furthermore, the radius r of the outer fillet 3 is 3-5 mm. This setting can avoid scratches on the rolled workpiece during the rolling process, and also avoid damage to the die caused by bumps.

[0040] Furthermore, the nominal diameter of round steel is 20mm to 130mm.

[0041] Furthermore, the slot width Bk is 1.01 times the hole height hk, that is, Bk = 1.01 × hk.

[0042] Furthermore, when using a die to roll round steel, the ellipticity of the round steel with a nominal diameter less than or equal to 70 mm is ≤0.4 mm, and the ellipticity of the round steel with a nominal diameter greater than 70 mm is ≤0.6 mm.

[0043] The rolling pass for round steel is a two-roll mill pass. Through precise design of the rolling pass for round steel, the two-roll mill achieves the precision requirements of a three-roll mill, thus resolving the contradiction between quality and investment.

[0044] This invention also discloses a design method for the above-mentioned rolled round steel die, such as... Figure 7 As shown, it includes the following steps:

[0045] Step 1) Calculate the values ​​of the die profile parameters, including the die profile height hk, roll gap S, groove width Bk, expansion angle θ, and radius r of the outer fillet 3;

[0046] Step 2) Draw base circle 1, as shown Figure 1 As shown, a base circle 1 with a diameter equal to the hole height hk is drawn using drawing software;

[0047] Step 3) Draw the roll gap, as shown Figure 2 As shown, the roll gap line 4 is drawn by shifting the vertical center line of the base circle 1 to the left and right by S / 2.

[0048] Step 4) Draw the groove line 5, as shown. Figure 3 As shown, the horizontal center line of the base circle 1 is shifted upwards and downwards by Bk / 2 to form the groove line 5;

[0049] Step 5) Draw the expansion angle, such as Figure 4 As shown, the transverse centerline of base circle 1 is rotated by θ in the counterclockwise and clockwise directions with the center of base circle 1 as the axis to obtain two expansion angle lines 6;

[0050] Step 6) Draw expansion segment 2, as follows Figure 5 As shown, the starting point of expansion segment 2 is located at the intersection of expansion angle line 6 and base circle 1, and the ending point of expansion segment 2 is located at the intersection of groove line 5 and roll gap line 4, making expansion segment 2 externally tangent to base circle 1.

[0051] First, draw a straight line. The starting point of the line is located at the intersection of the groove line 5 and the roll gap line 4, and the ending point of the line is located at the intersection of the expansion angle line 6 and the base circle 1.

[0052] Then draw the perpendicular bisector of the straight line. Using the intersection of the perpendicular bisector of the straight line and the expansion angle line 6 as the center, draw the expansion circle. The expansion circle passes through the intersection of the expansion angle line 6 and the base circle 1. The arc between the intersection of the expansion angle line 6 and the base circle 1 and the intersection of the groove line 5 and the roll gap line 4 is the expansion segment 2.

[0053] In one embodiment of the present invention, the nominal diameter d of the target round steel being rolled is 60 mm, the roll height hk = 1.012 × d = 60.72 mm, the roll gap S = 0.1 × hk = 6.072 mm, the groove width Bk = 1.01 × d = 61.3272 mm, the expansion angle θ = 30°, the radius r of the outer fillet 3 = 4 mm, and the radius R of the expansion circle is measured to be 36.55 mm.

[0054] Step 7) Draw the outer fillet 3. Use a rounded chamfer to draw the outer fillet 3 between the roller seam line 4 and the expansion section 2, as shown below. Figure 6 As shown, the mirror expansion segment 2 and the outer fillet 3 complete the graphic, delete the redundant line segments of the graphic, and retain the target graphic.

[0055] This design method first calculates the slot width Bk using a formula, and then uses a graphical method to determine the unique expansion circle. Compared with existing roll pass design methods, this method reverses the order of determining the slot and the expansion circle, allowing for precise calculation of the expansion circle's dimensions using a formula.

[0056] In the actual operation of the production line, the round steel rolled by the rolling round steel roll pass designed using the above design method has good ellipticity, stable rolling quality, strong steel throughput capacity of the roll pass, high dimensional accuracy, and the formula calculation method is simple.

[0057] This method for designing rolling mill round steel profiles significantly reduces the design difficulty by using fixed calculation formulas and drawing software for auxiliary drawing. After stable rolling, the technical specifications can be achieved as follows: ≤φ70mm round steel, ellipticity ≤0.4mm; >φ70mm round steel, ellipticity ≤0.6mm.

[0058] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0059] A rolling pass and design method for round steel bars are disclosed. This rolling pass can be used for both finished round steel bars and transition / extension passes, exhibiting strong adaptability. It can be used to produce bearing steel, gear steel, spring steel, carbon alloy steel, and some high-alloy steels. This rolling pass does not overly rely on equipment precision, and can achieve the precision of three-roll mill rolling using a two-roll mill, resolving the conflict between quality and investment. Using this pass for rolling round steel bars results in stable rolling quality, strong throughput capacity, and high dimensional accuracy.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rolling mill die, characterized in that, Includes a base circle and width expansion portions located on both sides of the base circle, wherein, The width expansion portion has an arc-shaped expansion section; The diameter of the base circle is called the height hk of the hole, and the height hk of the hole is 1.011 to 1.013 times the nominal diameter d of the round steel. The slot width Bk is greater than the hole height hk; The slot width Bk is 1.01 times the height hk of the hole. The expansion circle containing the expansion section is internally tangent to the base circle, and the other end of the expansion section is connected to the intersection of the slot line and the roll gap line. The expansion angle θ of the expansion segment is 15° to 30°.

2. The rolling die for round steel according to claim 1, characterized in that, The roll gap S is 0.1 times the height hk of the die.

3. The rolling die for round steel according to claim 1, characterized in that, The radius r of the outer fillet is 3 to 5 mm.

4. The rolling die for round steel according to claim 1, characterized in that, The nominal diameter of the round steel is 20mm to 130mm.

5. The rolling die for round steel according to claim 1, characterized in that, The expansion angle θ of the expansion segment is 30°.

6. The rolling die for round steel according to claim 1, characterized in that, The round steel is rolled using the aforementioned die, wherein the ellipticity of the round steel with a nominal diameter less than or equal to 70 mm is ≤0.4 mm, and the ellipticity of the round steel with a nominal diameter greater than 70 mm is ≤0.6 mm.

7. A method for designing a rolling mill pass according to any one of claims 1 to 6, comprising constructing the pass using drawing software, characterized in that, Includes the following steps: Step 1) Calculate the values ​​of the die profile parameters, including die height hk, roll gap S, slot width Bk, expansion angle θ, and outer fillet radius r; Step 2) Draw the base circle. Use drawing software to draw a base circle with a diameter equal to the hole height hk. Step 3) Draw the roll gap. Offset the vertical center line of the base circle to the left and right by S / 2 to draw the roll gap line. Step 4) Draw the groove line by shifting the horizontal center line of the base circle upwards and downwards by Bk / 2 to form the groove line; Step 5) Draw the expansion angles. Rotate the horizontal center line of the base circle by θ in the counterclockwise and clockwise directions respectively, with the center of the base circle as the axis, to obtain two expansion angle lines. Step 6) Draw the expansion segment. The starting point of the expansion segment is located at the intersection of the expansion angle line and the base circle, and the ending point of the expansion segment is located at the intersection of the groove line and the roll gap line. The expansion circle containing the expansion segment is internally tangent to the base circle. Step 7) Draw the outer fillet, mirror the expansion segment and complete the shape with the outer fillet, delete the redundant line segments of the shape, and keep the target shape.

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