A pinch roll device for ribbed steel bars

Abstract

The present invention relates to a pinch roll device for ribbed steel bars, which includes an upper roll and a lower roll. On the roll surfaces of the upper roll and the lower roll, annular grooves with the same shape are respectively provided opposite to each other along the circumferential direction thereof. The two side walls of each annular groove are two inclined surfaces which are symmetrically arranged. The calculation formula for the included angle between the two inclined surfaces is as follows: δ = 360° - 2×(δ1 + δ2), where δ1 = arccos((d3 - d2) / 2l1), δ2 = arctan(l2 / l3), δ represents the included angle between the two inclined surfaces, and d2 represents the diameter of the circumscribed circle where the trapezoidal cross-section of the longitudinal rib is located in the cross-section of the ribbed steel bar. The pinch roll device for ribbed steel bars of the present invention can effectively solve the problem that during the clamping and braking process of the ribbed steel bar by the pinch roll device, the transverse ribs of the ribbed steel bar are prone to indentation deformation, resulting in unqualified products or being listed as disputed products.

Description

Technical Field

[0001] The invention relates to the field of metallurgical steel rolling high-speed bar threaded steel production line, in particular to a pinch roller device for threaded steel. Background Art

[0002] Rebar is the common name for hot-rolled steel strips, which are usually round in cross section and ribbed on the surface. In the production line of rebar bars (referred to as rolled products), high-speed bar production lines have the advantages of high rolling speed, good product surface quality, and high yield rate, and are now widely used by domestic steel mills. The finished product export speed of the high-speed bar production line can reach 45m / s. After the rolling of the rolled products is completed, it is necessary to apply a certain clamping force to the tail of the rolled products through the pinch roller device to brake them, and brake the rolled products from high-speed clamping to a very low speed in a very short time (generally 0.8s).

[0003] At present, conventional pinch roller devices such as Figure 1 As shown in the figure, the annular grooves on the upper roller 01 and the lower roller 02 are both arc surface transitions. The pinch roller device will automatically clamp the workpiece to the shortest position from the center of the base circle on the cross section of the workpiece that can be enclosed during the clamping process. Figure 1 For the clamping roller device, the workpiece is not stable after being clamped and will rotate left and right. Therefore, it is often easy to clamp the top position of the cross rib of the workpiece, so that the top position of the cross rib of the workpiece is in contact with the annular grooves on both sides in two partial arcs.

[0004] However, in actual production, the temperature of the rolled product is generally around 800-950°C. Under high temperature conditions, the deformation resistance of the rolled product is low. When the pinch roller device presses on the transverse ribs of the rolled product, it is easy for the transverse ribs to undergo plastic deformation and produce indentations. Moreover, this deformation is unacceptable if it exceeds a certain degree. According to the national standard "Steel for Reinforced Concrete Part 2: Hot-rolled Ribbed Steel Bars" GB1499.2-2018, the height of the transverse ribs of rebars has strict tolerance requirements. For example, the height requirement for the transverse ribs of rebars with a nominal diameter of 10mm is ±0.4mm. When the height of the transverse ribs exceeds the tolerance requirements, the product is unqualified. In addition, when the height of the transverse ribs of the rebar meets the tolerance requirements, but the positions near the top of the transverse ribs on both sides (for example Figure 3 If the indentation in the fifth area E and the sixth area F) is too obvious, the product may be classified as an objectionable product or a defective product, which will affect the sales of the product.

[0005] In the prior art, the method generally adopts adding multiple pinch rollers to arrange them side by side to clamp the rolled piece at the same time, and reducing the clamping force of each pinch roller to reduce the indentation on the transverse rib. However, this method not only has high electricity and maintenance costs, but also has high difficulty in electronic control.

[0006] Accordingly, based on years of experience and practice in the relevant industry, the inventor of the present invention proposes a pinch roll device for ribbed steel to overcome the defects of the prior art. Summary of the Invention

[0007] The object of the present invention is to provide a pinch roll device for ribbed steel, which can effectively solve the problem that during the clamping and braking process of the ribbed steel by the pinch roll device, the transverse ribs of the ribbed steel are prone to indentation deformation, resulting in unqualified products or being listed as disputed products, and improve the product quality of the production line.

[0008] The object of the present invention is achieved as follows. A pinch roll device for ribbed steel includes an upper roll and a lower roll that are arranged parallel to each other at an interval. On the roll surfaces of the upper roll and the lower roll, annular grooves with the same shape are respectively provided opposite to each other along the circumferential direction. The two side walls of the annular groove are two inclined surfaces that are symmetrically arranged. The calculation formula for the included angle between the two inclined surfaces is as follows: δ = 360° - 2×(δ1 + δ2); where δ1 = arccos((d3 - d2) / 2l1), δ2 = arctan(l2 / l3), δ represents the included angle between the two inclined surfaces, δ1 represents the first included angle, δ2 represents the second included angle, d2 represents the diameter of the circumscribed circle where the trapezoidal cross-section of the longitudinal rib is located in the cross-section of the ribbed steel, d3 represents the diameter of the contour circle where the outer arc of the crescent-shaped cross-section of the transverse rib is located in the cross-section of the ribbed steel, l1 represents the distance between the centers of the circumscribed circle and the contour circle, l2 represents the distance between the centers of the base circle and the circumscribed circle of the ribbed steel, and l3 represents the distance between the centers of the base circle and the contour circle of the ribbed steel.

[0009] In a preferred embodiment of the present invention, the bottom of the annular groove is an arc surface, and the inclined directions of the two inclined surfaces are respectively tangent to the two sides of the arc surface.

[0010] In a preferred embodiment of the present invention, the radius of the arc surface is greater than zero and less than or equal to the radius of the circumscribed circle.

[0011] In a preferred embodiment of the present invention, the radius of the arc surface is equal to the radius of the circumscribed circle.

[0012] In a preferred embodiment of the present invention, the depth of the annular groove satisfies the following formula: H = (L - S) / 2; where L = 2l2 + d2, H represents the depth of the annular groove, L represents the total spacing, and S represents the preset value of the roll gap.

[0013] In a preferred embodiment of the present invention, the preset value of the roll gap is 1 - 2 mm.

[0014] In a preferred embodiment of the present invention, the axial width of the upper roll and the lower roll is (1.6 - 2.0) times the diameter of the base circle of the ribbed steel.

[0015] In a preferred embodiment of the present invention, the specifications of the ribbed steel bar are The included angle between the two inclined planes is 112.4°.

[0016] In a preferred embodiment of the present invention, the specifications of the ribbed steel bar are The included angle between the two inclined planes is 112.9°.

[0017] In a preferred embodiment of the present invention, the specifications of the ribbed steel bar are The included angle between the two inclined planes is 114.4°.

[0018] In a preferred embodiment of the present invention, the specifications of the ribbed steel bar are The included angle between the two inclined planes is 116.4°.

[0019] As described above, in the present invention, by changing the shape of the annular groove into a V-shaped groove and having special requirements for the included angle between the two inclined planes, the position between the two inclined planes along the diagonal direction in the pass of the entire pinch roll device is the position with the shortest distance in the pass, and when clamping the rolled piece, it can automatically clamp to the tangent points N1 and N1' on the cross-section of the rolled piece, forming a stable four-point contact, and the four contact points are all located between the transverse ribs and the longitudinal ribs and near the end of the transverse ribs, and will not affect the height of the transverse ribs. Furthermore, it effectively avoids the transverse ribs of the ribbed steel bar from being indented and deformed beyond the tolerance requirements of the transverse rib height during the clamping and braking process of the pinch roll device, and also avoids the obvious indentation near both sides of the top of the transverse rib from being listed as a disputed product, greatly reducing the unqualified rate and the disputed product rate of the product, and improving the product quality of the production line. At the same time, the entire device has a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following drawings are only intended to illustrate and explain the present invention schematically and do not limit the scope of the present invention.

[0021] Wherein:

[0022] Figure 1 : Schematic structural diagram of the pinch roll device in the prior art when clamping the ribbed steel bar.

[0023] Figure 2 : Schematic structural diagram of the ribbed steel bar.

[0024] Figure 3 : Schematic cross-sectional diagram of the ribbed steel bar.

[0025] Figure 4 : Schematic structural diagram of the upper roll and the lower roll of the pinch roll device provided by the present invention.

[0026] Figure 5: Schematic structure of the pinch roll device provided by the present invention when clamping ribbed steel bars Figure 1 。

[0027] Figure 6 : Schematic structure of the pinch roll device provided by the present invention when clamping ribbed steel bars Figure 2 。

[0028] Figure 7 : Schematic structure diagram of the circumscribed circle provided by the present invention.

[0029] Figure 8 : Schematic structure diagram of the circumscribed circle and one of the profile circles provided by the present invention.

[0030] Figure 9 : Schematic structure diagram of the circumscribed circle and another profile circle provided by the present invention.

[0031] Figure 10 : Schematic structure diagram of the pentagon formed by N1, N1′, O3, O3′ and the intersection point P provided by the present invention.

[0032] Figure 11 : Schematic structure diagram of the trapezoid formed by O2, O3, N1 and N2 provided by the present invention.

[0033] Figure 12 : Schematic structure diagram of the triangle formed by O1, O2 and O3 provided by the present invention.

[0034] Explanation of reference numerals in the drawings:

[0035] Prior art:

[0036] 01, upper roll roller; 02, lower roll roller;

[0037] The present invention:

[0038] 1, upper roll roller; 2, lower roll roller; 3, annular groove; 31, arc surface; 32, inclined surface;

[0039] 4, ribbed steel bar; 41, transverse rib; 42, longitudinal rib; 43, base circle. Detailed implementation manners

[0040] For a clearer understanding of the technical features, objectives and effects of the present invention, the specific implementation manners of the present invention will now be described with reference to the accompanying drawings.

[0041] Such as Figures 2 to 12As shown in the figure, this embodiment provides a pinch roll device for ribbed steel bars, which includes an upper roll 1 and a lower roll 2 that are arranged parallel to each other at an interval. On the roll surfaces of the upper roll 1 and the lower roll 2, annular grooves 3 with the same shape are respectively provided opposite to each other along the circumferential direction. The two side walls of the annular groove 3 are two inclined surfaces 32 that are symmetrically arranged. The calculation formula for the included angle δ between the two inclined surfaces 32 is as follows:

[0042] δ = 360° - 2×(δ1 + δ2); where δ1 = arccos((d3 - d2) / 2l1), δ2 = arctan(l2 / l3), and δ represents

[0043] the included angle between the two inclined surfaces 32, δ1 represents the first included angle, δ2 represents the second included angle, d2 represents the diameter of the circumscribed circle of the trapezoidal cross-section of the longitudinal rib 42 in the cross-section of the ribbed steel bar 4, d3 represents the diameter of the contour circle where the outer arc of the crescent-shaped cross-section of the transverse rib 41 in the cross-section of the ribbed steel bar 4 is located, l1 represents the distance between the center of the circumscribed circle and the center of the contour circle, l2 represents the distance between the center of the base circle 43 of the ribbed steel bar 4 and the center of the circumscribed circle, and l3 represents the distance between the center of the base circle 43 of the ribbed steel bar 4 and the center of the contour circle.

[0044] Specifically, the structure of the ribbed steel bar 4 is as Figure 2 and Figure 3 shown. According to the dimensional requirements of different specifications of ribbed steel bars 4 in the national standard GB1499.2 - 2018 and combined with the actual production dimensions, for the cross-section of a single ribbed steel bar 4, the intersection point M of its transverse rib 41 and the base circle 43 is the position closest to the center of the base circle 43 in the entire cross-section of the ribbed steel bar 4. However, when the pass of the pinch roll device clamps the rolled piece, the position on the cross-section of the rolled piece that is closest to the center of the base circle 43 and can be enveloped is near the intersection point M, that is Figure 3 within the four regions of the first region A1, the second region A2, the third region C, and the fourth region D shown in the figure.

[0045] In this embodiment, the pass formed by the included angle δ between the two inclined surfaces 32 obtained according to the above formula can ensure that the inclined surfaces 32 are in contact with the position on the cross-section of the rolled piece that is closest to the center of the base circle 43 and can be enveloped, and form stable four-point contact. The analysis is as follows:

[0046] Since the common specifications of ribbed steel bars 4 are and and other more than a dozen specifications, and the common specifications are relatively few. When designing, the descriptive geometry method can be used to determine the above included angle δ. As Figures 6 to 12 shown, specifically:

[0047] (1) According to the dimensional regulations of ribbed steel bars 4 of different specifications in GB1499.2-2018, the cross-sectional view of the ribbed steel bar 4 of this specification can be accurately drawn based on the top width a of the longitudinal rib, the height h of the transverse rib, the height h1 of the longitudinal rib, the base circle diameter d1 of the ribbed steel bar 4, the gap f1 at the end of the transverse rib (i.e., the gap between the ends of two opposite transverse ribs 41), and the longitudinal rib angle θ. The center of the base circle 43 is denoted as O1. Among them, when drawing the transverse rib 41 in the cross-section of the ribbed steel bar 4, first, the two end points of the transverse rib 41 that can be determined according to the gap f1 at the end of the transverse rib (i.e., the intersection points M of the two ends of the crescent-shaped cross-section of the transverse rib 41 and the base circle 43), and the outer point on the height h of the transverse rib can be determined according to the height h of the transverse rib (i.e., the point far from the base circle 43 in the height direction of the transverse rib, that is, the outermost point). By drawing a circle through these two end points and the outer point, the outer arc of the crescent shape where the transverse rib 41 is located can be drawn.

[0048] (2) As shown in Figure 6 and Figure 7 , an isosceles trapezoid can be determined based on the trapezoidal cross-section of the longitudinal rib 42 in the cross-section of the ribbed steel bar 4. The circumscribed circle with a diameter of d2 can be uniquely determined according to the four vertices of the isosceles trapezoid. The center of the circumscribed circle is denoted as O2. It should be noted that in actual processing, there are generally arc chamfers at the two outer vertices (i.e., the two vertices far from the base circle 43) of the longitudinal rib 42. Therefore, when determining the four vertices of the isosceles trapezoid, the tips of the two vertices with arc chamfers can be complemented to determine the four vertices of the isosceles trapezoid.

[0049] (3) As shown in Figure 6 , Figure 8 and Figure 9 , a contour circle with a diameter of d3 can be uniquely determined by the outer arc of the crescent-shaped cross-section of one of the transverse ribs 41 in the cross-section of the ribbed steel bar 4, and another contour circle with a diameter of d3 can be uniquely determined by the outer arc of the crescent-shaped cross-section of the other transverse rib 41. The centers of these two contour circles are denoted as O3 and O3′ respectively. It can be understood that the contour circle here is the same circle as the circle obtained by the aforementioned three-point circle-drawing method.

[0050] (4) As shown in Figure 6 , Figure 8 and Figure 9 , draw the first tangent line that is tangent to both the circumscribed circle and one of the contour circles. The two tangent points are denoted as N1 and N2 respectively; draw the second tangent line that is tangent to both the circumscribed circle and the other contour circle. The two tangent points are denoted as N1′ and N2′ respectively. The tangent points N1 and N1′ are the positions on the cross-section of the rolled piece that are closest to the center O1 of the base circle 43 and can be enveloped. Therefore, by taking the angle δ between the first tangent line and the second tangent line, it can be ensured that when the pass holds the rolled piece, it can effectively and stably hold the tangent points N1 and N1′.

[0051] When calculating this included angle δ, as Figure 10 shown, based on the pentagon formed by N1, N1′, O3, O3′, and the intersection point P of the first tangent and the second tangent point, it can be obtained that:

[0052] δ = 540° - 180° - 2×(δ1 + δ2) = 360° - 2×(δ1 + δ2);

[0053] As Figure 11 shown, based on the trapezoid formed by O2, O3, N1, and N2, it can be obtained that δ1 = arccos((d3 - d2) / 2l1); as Figure 12 shown, based on the triangle formed by O1, O2, and O3, it can be obtained that δ2 = arctan(l2 / l3). Among them, the first included angle δ1 is the included angle between the connecting line of O3O2 and the connecting line of O3N1, and the second included angle δ2 is the included angle between the connecting line of O3O1 and the connecting line of O3O2.

[0054] According to the above method and formula, the value of the included angle δ for ribbed bars 4 of different specifications can be obtained. For example, when the specification of ribbed bar 4 is the included angle δ between the two inclined surfaces 32 is 112.4°; when the specification of ribbed bar 4 is the included angle δ between the two inclined surfaces 32 is 112.9°; when the specification of ribbed bar 4 is the included angle δ between the two inclined surfaces 32 is 114.4°; when the specification of ribbed bar 4 is the included angle δ between the two inclined surfaces 32 is 116.4°.

[0055] Since the pinch roll device will automatically clamp the rolled piece to the position closest to the center O1 of the distance base circle 43 that can be enveloped on the cross-section of the rolled piece during the clamping process of the rolled piece, and generally it is the position with the shortest distance in the pass of the pinch roll device that finally clamps the position closest to the center O1 of the distance base circle 43 that can be enveloped on the cross-section of the rolled piece; if the clamping position is not the position closest to the center O1 of the distance base circle 43 that can be enveloped on the cross-section of the rolled piece, the rolled piece will keep rotating during the conveying process and is not stable. For Figure 1 the pass of the pinch roll device in Figure 1The position shown in [figure]. In this embodiment, the groove wall of the annular groove 3 is designed as an inclined surface 32, and the entire annular groove 3 forms a V-shaped groove. The hole shape of the entire pinch roll device is surrounded by two V-shaped grooves. The position with the shortest distance in the entire hole shape is the position between two inclined surfaces 32 along the diagonal direction in the two annular grooves 3.

[0056] Therefore, after a certain pressure is applied to the pinch roll device, under the condition that the included angle δ satisfies the above formula, due to its special hole shape design, the pinch roll device will automatically clamp the rolled piece near the four intersection points M with the shortest distance, so that the four inclined surfaces 32 are respectively in contact with the above-mentioned tangent points N1 and N1' on the outer wall of the deformed steel bar 4, realizing four-point contact. Even if it is initially clamped to other positions due to mistakes or other reasons, it will quickly adjust automatically under the action of the clamping force and be clamped to the position of four-point contact. In this way, on the one hand, it can improve the clamping stability and prevent the rolled piece from rotating during the conveying process; on the other hand, since the positions of the four-point contact are all between the transverse ribs 41 and the longitudinal ribs 42, even if indentations are generated at these four-point contact positions, they will not affect the height h of the transverse ribs, thus meeting the requirements of the national standard; moreover, the positions of the four-point contact are all close to the two ends on both sides of the transverse rib 41, and are relatively far from the vicinity of the highest position of the transverse rib 41 (i.e., the fifth region E and the sixth region F), so it also avoids the obvious indentations at the positions near the two sides of the top of the transverse rib 41 from being listed as defective products.

[0057] Thus, in this embodiment, by changing the shape of the annular groove 3 into a V-shaped groove and having special requirements for the included angle δ between the two inclined surfaces 32, the position between the two inclined surfaces 32 along the diagonal direction in the hole shape of the entire pinch roll device is the position with the shortest distance in the hole shape, and when clamping the rolled piece, it can automatically clamp to the positions of the tangent points N1 and N1' on the cross-section of the rolled piece, forming stable four-point contact, and the four contact points are all located between the transverse rib 41 and the longitudinal rib 42 and close to the end of the transverse rib 41, and will not affect the height h of the transverse rib. Furthermore, it effectively avoids the indentation deformation of the transverse rib 41 of the deformed steel bar 4 exceeding the tolerance requirements of the height h of the transverse rib during the clamping and braking process of the pinch roll device, and also avoids the obvious indentations at the positions near the two sides of the top of the transverse rib 41 from being listed as defective products, greatly reducing the unqualified rate and the defective product rate of the product, and improving the product quality of the production line. At the same time, the entire device has a simple structure and low cost.

[0058] In the specific implementation manner, in order to reduce the stress concentration phenomenon, the bottom of the annular groove 3 is an arc surface 31, and the inclined directions of the two inclined surfaces 32 are respectively tangent to the two side edges of the arc surface 31. Here, the arc surface 31 mentioned refers to the shape of the cross-section of the annular groove 3.

[0059] In practical applications, in order to prevent the longitudinal rib 42 of the deformed bar 4 from contacting the annular groove 3 when clamping the rolled piece and affecting the formation of stable four-point contact, the radius R of the arc surface 31 should satisfy: the radius R of the arc surface 31 is greater than zero and less than or equal to the radius of the circumscribed circle, that is, 0 < R ≤ d2 / 2. Within this range, it is possible to avoid the longitudinal rib 42 of the deformed bar 4 from contacting the bottom of the annular groove 3. Generally, for the convenience of machining and further reducing the influence of stress concentration, the radius R of the arc surface 31 is equal to the radius of the circumscribed circle.

[0060] Furthermore, the depth H of the annular groove 3 is also selected according to the specific specifications of the deformed bar 4 to ensure that stable four-point contact can be formed after clamping the rolled piece. As Figure 4 and Figure 6 shown, the depth H of the annular groove 3 should satisfy the following formula: H = (L - S) / 2, where L = 2l2 + d2, H represents the depth of the annular groove 3, L represents the total spacing, and S represents the preset value of the roll gap.

[0061] The preset value S of the roll gap mentioned here refers to the preset roll gap distance between the upper roll 1 and the lower roll 2 when the pinch roll device is closed. During production use, generally, the roll gap distance is first adjusted to the preset value S of the roll gap, and then the clamping force is increased to start normal clamping work. The preset value S of the roll gap is generally 1 - 2 mm, and is specifically selected according to the specifications of the deformed bar 4. When the specifications are large, the preset value S of the roll gap takes a larger value; when the specifications are small, the preset value S of the roll gap takes a smaller value.

[0062] Furthermore, for the widths B of the upper roll 1 and the lower roll 2 along their axial directions, they are generally (1.6 - 2.0) times the base circle diameter d1 of the deformed bar 4, that is, B = (1.6 - 2.0) × d1, and the specific width is determined according to the actual specifications of the deformed bar 4.

[0063] During specific use, when using the pinch roll device with the above pass shape for production, the operation method is as follows:

[0064] Before braking the rolled piece, first adjust the distance between the upper roll 1 and the lower roll 2 to the preset roll gap distance S, and close the pinch roll device in advance to apply a relatively small clamping force (such as 2 - 3 kN) to the rolled piece by the pinch roll device. Since the positions of the above-mentioned tangent points N1 and N1' are the positions where the distance from the center O1 of the base circle 43 that can be enveloped on the cross-section of the rolled piece is the shortest, during the conveying process of the rolled piece, the pinch roll device will automatically adapt the rolled piece to Figure 5 and Figure 6 the state, forming four-point contact. At this time, the positions of the tangent points N1 and N1' on the rolled piece are in contact with the four inclined surfaces 32 but are not yet pressed tightly.

[0065] When the rolled piece starts to brake, the pinch roll device applies the required clamping force (for example, 8 - 10 kN). After applying the force, the pinch roll device clamps and brakes the rolled piece and presses it tightly. At this time, the pinch roll device has stably restricted the rolled piece through four-point contact. The rolled piece will not rotate left and right. The positions where the rolled piece produces indentations are all close to the two ends on both sides of the transverse rib 41, and will not affect the height h of the transverse rib required by the national standard, nor will it produce obvious indentations at the positions near the two sides at the top of the transverse rib 41, thus meeting the requirements of production for product quality.

[0066] In addition, it should be noted that the pass shape of the pinch roll device in this embodiment is mainly applicable to the rolled piece with the longitudinal rib 42 placed vertically after the rolling of the ribbed steel 4. In this way, when the rolled piece is conveyed into the pinch roll device, it can be more smoothly clamped in Figure 5 and Figure 6 the orientation shown in, forming a stable four-point contact.

[0067] The above is only a schematic specific embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A pinch roll device for ribbed steel bars, characterized in that, It includes an upper roller and a lower roller which are arranged at a parallel interval up and down; On the roller surfaces of the upper roller and the lower roller, annular grooves with the same shape are respectively arranged oppositely along the circumferences thereof. The two side walls of each annular groove are two inclined surfaces which are symmetrically arranged; The calculation formula for the included angle between the two inclined surfaces is as follows: δ = 360° - 2×(δ1 + δ2); Wherein, δ1 = arccos((d3 - d2) / 2l1), δ2 = arctan(l2 / l3). δ represents the included angle between the two inclined surfaces, δ1 represents the first included angle, δ2 represents the second included angle, d2 represents the diameter of the circumscribed circle where the trapezoidal cross-section of the longitudinal rib is located in the cross-section of the ribbed steel, d3 represents the diameter of the contour circle where the outer arc of the crescent-shaped cross-section of the transverse rib is located in the cross-section of the ribbed steel, l1 represents the distance between the centers of the circumscribed circle and the contour circle, l2 represents the distance between the center of the base circle of the ribbed steel and the center of the circumscribed circle, and l3 represents the distance between the center of the base circle of the ribbed steel and the center of the contour circle; The bottom of the annular groove is an arc surface, and the inclined directions of the two inclined surfaces are respectively tangent to the two sides of the arc surface; the width of the upper roller and the lower roller along their axial directions is 1.6 - 2.0 times the diameter of the base circle of the ribbed steel.

2. The pinch roll device for ribbed steel according to claim 1, wherein The radius of the arc surface is greater than zero and less than or equal to the radius of the circumscribed circle.

3. The pinch roll device for ribbed steel according to claim 2, wherein The radius of the arc surface is equal to the radius of the circumscribed circle.

4. The pinch roll device for ribbed steel according to claim 3, wherein The depth of the annular groove satisfies the following formula: H = (L - S) / 2; wherein, L = 2l2 + d2, H represents the depth of the annular groove, L represents the total spacing, and S represents the preset value of the roll gap.

5. The pinch roll device for ribbed steel according to claim 4, wherein The preset value of the roll gap is 1 - 2 mm.

6. The pinch roll device for ribbed steel according to claim 1, wherein The specification of the deformed steel bar is The included angle between the two inclined surfaces is 112.4°.

7. The pinch roll device for ribbed steel according to claim 1, wherein The specifications of the deformed steel bar are The included angle between the two inclined surfaces is 112.9°.

8. The pinch roll device for ribbed steel according to claim 1, wherein The specifications of the deformed steel bar are The included angle between the two inclined surfaces is 114.4°.

9. The pinch roll device for ribbed steel according to claim 1, wherein The specification of the deformed steel bar is The included angle between the two inclined surfaces is 116.4°.

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