A guide for a three-high cold rolling mill
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANNAN NANJING STEEL HELI NEW MATERIALS TECHNOLOGY CO LTD
- Filing Date
- 2025-06-05
- Publication Date
- 2026-06-12
AI Technical Summary
The existing cold rolling three-roll mill has problems when producing three-sided ribbed steel bars. Inaccurate guides cause scratches and wear on the surface of the steel bars, which cannot meet the requirements of the new national standard. Furthermore, the inaccurate alignment between the guides and the roll grooves leads to poor rolling quality and severe roll wear.
A guide for a cold rolling three-roll mill is designed, which adopts an inner and outer cylinder structure and a guide arm assembly. By adjusting the combination of the spinning wire and the compression spring, the pressure between the guide wheel and the steel bar surface can be adjusted, ensuring the precise correspondence between the guide wheel and the roll groove, reducing wear and improving rolling quality.
It achieves precise guidance for the guide rollers of the cold rolling three-roll mill, reduces uneven wear of the guide rollers, improves the rolling quality of the forming mill, reduces impact and wear during the rolling process, and meets the product quality requirements of the new national standard.
Smart Images
Figure CN122184115A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to steel bar production equipment, and in particular to a guide for a cold rolling three-roll mill, belonging to the technical field of cold rolling equipment. Background Technology
[0002] The new national standard GB13788-2024 for cold-rolled ribbed steel bars was released and implemented in September 2024. The new standard limits the shape of CRB550 products to three-sided ribbed steel bars. Prior to this, some three-sided ribbed cold-rolled ribbed steel bar products on the market were produced using passive rolling. The three-roll mill no longer had a main drive system; instead, traction rollers were installed upstream of the mill. The steel bar was wound several times on the traction rollers, and the driving force generated by the friction of the traction rollers pulled the steel bar, thus achieving passive rolling. The passive three-roll mill structure is relatively simple, with the two stages (reduction and forming) very close together. Even without guide rollers, the correct position of the reduced-diameter steel bar during forming rolling can be ensured. Therefore, the reduction mill in the front stage also acts as a guide. However, the passive rolling process also has its inherent drawbacks. Since the steel bar must pass through the traction rollers after forming, it also needs to be straightened by a straightening mechanism when producing straight steel bars. These two processes inevitably generate strong friction on the outer circle of the reinforcing bar, especially abrading the transverse ribs, ultimately causing surface scratches or even substandard transverse rib height, resulting in quality that does not meet standards. Therefore, the scientific production process for three-sided ribbed products still uses an active forming mill. This requires a guide mechanism before the forming mill. The cross-section of the product after the three-sided ribbed reduction mill is approximately triangular. When the forming mill is an active mill, the semi-finished product with the triangular cross-section needs to be accurately guided into the grooves on the forming mill rolls to obtain a qualified product. The more accurate the correspondence between the reinforcing bar and the roll groove, the better the quality of the product after forming and rolling, and the less negative effects such as impact and wear on the rolls during rolling. There are many mill guides currently used in reinforcing bar production, but mill guides applicable to the production of cold-rolled three-sided ribbed cold-rolled reinforcing bars are rare. Summary of the Invention
[0003] The purpose of this invention is to provide a guide before the forming mill for the production of cold-rolled three-sided ribbed steel bars.
[0004] To achieve the objective of this invention, the following technical solution is adopted: A guide for a cold rolling three-roll mill includes a base, on which a guide cylinder is fixedly connected or integrally disposed. An outer cylinder is slidably disposed inside the guide cylinder, and an inner cylinder is slidably disposed inside the outer cylinder. Both ends of the inner cylinder extend out of the outer cylinder, and the outlet end of the inner cylinder is a flared mouth. Three spring seat holes are uniformly machined circumferentially around the outer periphery of the inner cylinder, and springs are installed in the spring seat holes. Three guide arms are hinged to the circumferential surface of the outlet end of the inner cylinder, and the guide arms press on the springs. A guide wheel is rotatably mounted on the front end of the guide arm, and the reinforcing bar passes between the three guide wheels after exiting the inner cylinder.
[0005] Furthermore; the front part of the outer cylinder has three inclined surfaces A, the inner surface of the rear end of the three guide arms is an inclined surface B that is adapted to the inclined surface A, the rear end of the inner cylinder extends out of the outer cylinder and is threaded, an annular groove is machined on the circumferential surface of the outer cylinder near the rear end, the retaining ring is rotatably set in the retaining ring groove, and a nut is screwed onto the thread at the rear end of the inner cylinder and the nut is fixedly connected to the retaining ring.
[0006] Furthermore, an axial elongated hole is provided on the guide cylinder wall, and an axially oriented rack is fixedly connected to the outer cylinder wall. The rack protrudes from the elongated hole, and a gear is rotatably installed on the rack, meshing with the rack.
[0007] Furthermore, an axial keyway is provided on the inner wall of the outer cylinder, and a guide key is fixedly connected to the outer wall of the inner cylinder, with the guide key located in the keyway.
[0008] Furthermore, a set screw hole is machined on the guide cylinder, and a set screw is screwed into the set screw hole to lock the outer cylinder and the guide cylinder together.
[0009] Furthermore, a through hole is machined near the rear end of the guide arm. The axis of the through hole is perpendicular to the inclined plane B. The upper half of the through hole is a screw hole or the entire through hole is a screw hole. An adjusting screw is screwed into the screw hole. A compression spring is set between the adjusting screw and the inclined plane. The two ends of the compression spring abut against the inclined plane B and the end of the adjusting screw, respectively. There is a gap between the inclined plane A and the inclined plane B.
[0010] The positive and beneficial technical effects of this invention are as follows: this guide can achieve precise guidance, which will be described in detail with reference to specific embodiments. Attached Figure Description
[0011] Figure 1 This is a cross-sectional view of the invention from front to back.
[0012] Figure 2 This is a rear view schematic diagram of the present invention.
[0013] Figure 3 yes Figure 1 A schematic diagram of the cross-section along the AA direction.
[0014] Figure 4This is an enlarged schematic diagram of the adjusting screw. Detailed Implementation
[0015] To more fully explain the implementation of the present invention, implementation examples are provided. These implementation examples are merely illustrative of the present invention and do not limit the scope of the present invention.
[0016] The invention will be further explained in detail with reference to the accompanying drawings, in which the following references are made: 1: base; 2: guide cylinder; 3: outer cylinder; 4: inner cylinder; 6: guide arm; 7: spring; 8: inclined plane A; 9: inclined plane B; 10: guide wheel; 11: guide key; 12: rack; 13: set screw; 14: retaining ring; 15: nut; 16: gear; 17: bell mouth; 18: adjusting screw; 19: compression spring.
[0017] As shown in the attached diagram, a guide for a cold rolling three-roll mill is provided. The cold rolling three-roll mill is a power-driven active mill, comprising a base 1. A guide cylinder 2 is fixedly connected to or integrally mounted on the base. An outer cylinder 3 is slidably fitted inside the guide cylinder. A set screw hole is machined on the guide cylinder, and a set screw 12 is screwed into the set screw hole to lock the outer cylinder and the guide cylinder together. An axial elongated hole is formed on the wall of the guide cylinder. An axially oriented rack 11 is fixedly connected to the wall of the outer cylinder, protruding from the elongated hole. A gear 15 is rotatably mounted on the rack, meshing with it. The front-to-back position of the outer cylinder can be adjusted by rotating the gear after releasing the set screw.
[0018] An inner cylinder 3 is slidably disposed inside the outer cylinder 2. An axial keyway is provided on the inner wall of the outer cylinder, and a guide key 10 is fixedly connected to the outer wall of the inner cylinder, with the guide key located in the keyway.
[0019] Both ends of the inner cylinder extend out of the outer cylinder. The outlet end of the inner cylinder is a flared mouth 16, which is defined as the front. Three spring seat holes are evenly machined along the circumference of the outer circumference of the inner cylinder. Springs 6 are installed in the spring seat holes. Three guide arms 6 are hinged to the circumferential surface of the outlet end of the inner cylinder. The three guide arms are evenly distributed on the circumferential surface of the inner cylinder. The guide arms press on the springs. Guide wheels 19 are rotatably installed at the front end of the guide arms. After the steel bar exits from the inner cylinder, it passes between the three guide wheels. The outer cylinder has three inclined surfaces A7 at its front. The inner surfaces of the rear ends of the three guide arms are inclined surfaces B8 that are adapted to inclined surfaces A. The inner cylinder has threads machined on its circumferential surface extending from the outer cylinder. An annular groove is machined on the circumferential surface of the outer cylinder near its rear end. A retaining ring 13 is rotatably disposed in the retaining ring groove. A nut 14 is screwed onto the thread at the rear end of the inner cylinder. The nut is fixedly connected to the retaining ring. The retaining ring is limited along the axial direction of the outer cylinder. Rotating the nut can drive the inner cylinder to move relative to the outer cylinder along the axial direction, thereby adjusting the opening size between the three guide wheels. As a further optimization, in this embodiment, a through hole is machined near the rear end of the guide arm 6. The axis of the through hole is perpendicular to the inclined surface B. The upper half of the through hole is a screw hole or the entire through hole is a screw hole. An adjusting screw 17 is screwed into the screw hole. A compression spring 18 is provided between the adjusting screw and the inclined surface. The two ends of the compression spring abut against the inclined surface B and the end of the adjusting screw, respectively. There is a gap between the inclined surface A and the inclined surface B.
[0020] Due to inherent errors in the manufacturing and installation of rolling mill guides, even if the designed guides correspond precisely to the roll grooves on the forming mill, it is difficult to guarantee a perfect alignment after actual installation. The same problem exists with the guide wheel mechanism. If a rigid component is used to drive the guide arm to press against the three surfaces of the rebar, the pressure exerted by the three guide wheels on the rebar will not be equal. This will lead to asynchronous wear of the three guide wheels, resulting in guide inaccuracies during production. Guide inaccuracies will generate uneven radial reaction forces on the equipment components when the rebar passes through during production, resulting in poor rolling quality, accelerated wear of certain parts of the guide wheels and rolls in a certain direction, and increased rolling costs. This guide is installed in front of the forming mill in cold rolling. The forming mill is an active mill. During use, first rotate the nut to increase the gap between inclined planes A and B (ideally, the spring should no longer exert pressure on inclined plane A before creating a certain gap; this ensures the guide wheel end is not subjected to force at inclined plane A when lifted). This increases the opening between the three guide wheels, allowing the reinforcing bar to pass smoothly. The reinforcing bar enters from the rear end, exits through the flared opening, and then passes between the three guide wheels into the groove of the forming roll of the forming mill. Then, rotate the nut again to adjust the gap between inclined planes A and B. Adjust the spring pressure on inclined plane B by adjusting the screw. The pressure of the three guide rollers on the rebar surface can be adjusted independently. By adjusting the spiral wire, the opening formed by the three guide rollers is displaced, making the alignment between the guide rollers and the grooves on the rolls more precise. This achieves accurate guidance and ensures that the pressure between the three guide rollers and the rebar is consistent. As a result, the wear of the three guide rollers is basically the same throughout their service life, ensuring accuracy during use. This improves the rolling quality of the forming mill and reduces the negative effects such as impact and wear on the rolls caused by inaccurate guides during the rolling process.
[0021] A method for achieving precise guidance in a cold-rolled three-roll mill, wherein the cold-rolled three-roll mill is a driven, active mill, specifically a forming mill, employs the aforementioned cold-rolled three-roll mill guide. The guide is installed before the forming mill and precise guidance is achieved through the following method: A cold-rolled three-roll mill guide is installed according to the design height. After adjusting the distance between the guide wheel and the forming mill using the drive gear adjusting cylinder, the nut is rotated to increase the gap between inclined planes A and B. Ideally, the spring should no longer exert pressure on inclined plane A before allowing for a certain gap. At this point, when the guide wheel end is lifted, it is not subjected to force at inclined plane A. The opening between the three guide wheels can be increased to allow the formed and rolled steel bars to pass smoothly. The steel bars then pass from the rear... After entering through the flared end and exiting through the three guide rollers, the material enters the groove of the forming roll of the forming mill. The nut is then rotated to adjust the gap between inclined surfaces A and B. The two ends of the compression spring exert pressure on inclined surface A and the rotating wire, respectively. Adjusting the rotating wire adjusts the pressure of the compression spring on inclined surface B and the pressure of the guide rollers on the rebar surface. Since the pressure of the three guide rollers on the rebar surface can be adjusted individually, one, two, or three adjusting rotating wires can cause displacement of the opening formed by the three guide rollers, ensuring precise alignment between the guide rollers and the grooves on the roll, achieving accurate guidance. Simultaneously, the pressure between the three guide rollers and the rebar is consistent, ensuring synchronized wear of the three guide rollers during use and guaranteeing accurate guidance throughout the entire service life of the guide rollers.
[0022] After a detailed description of the embodiments of the present invention, those skilled in the art will clearly understand that various changes and modifications can be made without departing from the scope and spirit of the above-mentioned patent applications. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention, and the present invention is not limited to the embodiments of the examples given in the specification.
Claims
1. A guide for a cold rolling three-roll mill, comprising a base, characterized in that: The base is fixedly connected to or integrally provided with a guide cylinder. The outer cylinder is slidably fitted inside the guide cylinder, and the inner cylinder is slidably installed inside the outer cylinder. Both ends of the inner cylinder extend out of the outer cylinder. The outlet end of the inner cylinder is a flared mouth. Three spring seat holes are evenly machined circumferentially on the outer periphery of the inner cylinder. The springs are installed in the spring seat holes. Three guide arms are hinged to the circumferential surface of the outlet end of the inner cylinder. The guide arms press on the springs. The front end of the guide arms is rotatably mounted with a guide wheel. The steel bar passes through the three guide wheels after exiting the inner cylinder.
2. A guide for a cold rolling three-roll mill according to claim 1, characterized in that: The outer cylinder has three inclined surfaces A at its front. The inner surfaces of the rear ends of the three guide arms are inclined surfaces B that are adapted to the inclined surfaces A. The inner cylinder has threads machined on the circumferential surface extending from the outer cylinder at its rear end. An annular groove is machined on the circumferential surface of the outer cylinder near the rear end. The retaining ring is rotatably set in the retaining ring groove. A nut is screwed onto the thread at the rear end of the inner cylinder and is fixedly connected to the retaining ring.
3. A guide for a cold rolling three-roll mill according to claim 1, characterized in that: An axial elongated hole is provided on the guide cylinder wall, and an axial rack is fixedly connected to the outer cylinder wall. The rack protrudes from the elongated hole, and a gear is rotatably installed on the rack, meshing with the rack.
4. A guide for a cold rolling three-roll mill according to claim 1, characterized in that: An axial keyway is provided on the inner wall of the outer cylinder, and a guide key is fixedly connected to the outer wall of the inner cylinder, with the guide key located in the keyway.
5. A guide for a cold rolling three-roll mill according to claim 1, characterized in that: The guide cylinder has a set screw hole, and a set screw is screwed into the set screw hole to lock the outer cylinder and the guide cylinder together.
6. A guide for a cold rolling three-roll mill according to claim 1, characterized in that: Near the rear end of the guide arm, there is a through hole. The axis of the through hole is perpendicular to the inclined plane B. The upper half of the through hole is a screw hole or the entire through hole is a screw hole. An adjusting screw is screwed into the screw hole. A compression spring is set between the adjusting screw and the inclined plane. The two ends of the compression spring abut against the inclined plane B and the end of the adjusting screw, respectively. There is a gap between the inclined plane A and the inclined plane B.