A two-high short stress line rolling mill with load down setting by two modes on the piston

Abstract

The application discloses a piston-over type double-mode adjusting two-roller short stress line rolling mill with load pressure reduction. The application comprises a containing stroke cavity arranged in the upper bearing seat corresponding to the position of the nut, and a hydraulic cylinder arranged in the containing stroke cavity. The cylinder body of the hydraulic cylinder is installed in the containing stroke cavity, and the piston of the hydraulic cylinder is fixedly connected with the nut. Alternatively, the piston of the hydraulic cylinder is installed in the containing stroke cavity, and the cylinder body of the hydraulic cylinder is fixedly connected with the nut. The application is based on the traditional pull rod (screw rod), nut mechanism and roll gap adjusting mechanism, and the hydraulic cylinder for fine adjustment driving of the center distance of the upper and lower bearing seats is connected in series in the pull rod and nut mechanism, so that the two sets of mechanisms for respectively adjusting the center distance of the upper and lower bearing seats can be used in different process stages and can act on the same side of the upper and lower bearing seats.

Description

Technical Field

[0001] The present invention relates to the technical field of a two-roller short stress line rolling mill for bar and profile rolling equipment, and specifically to a piston-mounted dual-mode adjustable load-down two-roller short stress line rolling mill; the invention is used to solve the problem of online dynamic adjustment of the reduction amount in the rolling process of high-precision bar and profile products. Background Art

[0002] Small bar and section rolling workshops generally use two-roller short stress line rolling mills, which have the characteristics of light weight, simple operation, quick replacement, and reliable operation. It has become the most widely used rolling mill model in the world's bar and small steel production lines.

[0003] Traditional two-roller short-stress line mills, used on rolling lines, rely on offline standby, roll room assembly, and complete machine replacement. Due to their complex structure and lengthy assembly times, to improve rolling line availability, assembly and adjustment are performed in the roll maintenance shop, with multiple mills used for backup and rotation online. While the mill is in operation, roll relative position parameters are adjusted without steel being passed through the mill.

[0004] In recent years, in order to meet the demand for high-precision, high-value-added profile products in the manufacturing industry and the demand for intelligent rolling technology, and to improve the cross-sectional accuracy and head and tail tolerance accuracy of profile products, the demand has been put forward for the online load reduction adjustment function of the two-roll short stress line rolling mill under load reduction conditions. The reduction amount refers to the adjustment amount of the center distance between the two rollers. The traditional two-roll short stress line rolling mills currently in common use do not have the conditions for online load reduction adjustment function, which seriously restricts the improvement of rolling process conditions. Improving the online load reduction adjustment function of the short stress line rolling mill has become a key and common problem in the rolling process of high-precision profile products in the industry.

[0005] The dual-mode reduction adjustment device for a two-roll short stress line rolling mill of the present invention improves the reduction mechanism of the two-roll short stress line rolling mill, meets the functional conditions for online load reduction adjustment of the rolls of the two-roll short stress line rolling mill, can achieve effective matching of rolling process technology and equipment, solve the problem of high-precision long product products, and meet the needs of process regulation automation.

[0006] The traditional two-roller short stress line rolling mill uses two tie rods with positive and negative threads to connect the bearing seats at both ends of the upper and lower rolls on the transmission side and the operating side, and the nuts fixed in the bearing seats are used to withstand the rolling force under the mechanical condition of shortening the stress line; the rotating tie rod changes the center distance between the upper and lower rolls, that is, the roll gap is adjusted to meet the rolling process hole requirements.

[0007] The hold-down adjustment mechanism is used to adjust the center distance between the upper and lower rollers. It primarily consists of a tie rod mechanism connecting the bearing seats on the transmission and operating sides of the upper and lower rollers of the rolling mill, and a roll gap adjustment drive mechanism. The hold-down adjustment mechanism utilizes a tie rod-screw structure connecting the upper and lower bearing seats. This mechanism, through the roll gap adjustment drive mechanism located at the top of the two-axis short stress line mill, simultaneously drives the rotation of four tie rods at both ends of the upper and lower bearing seats. The screws are provided with positive and negative threads, corresponding to nuts fixed in the upper and lower bearing seats, which are fixed in the axial position and cannot rotate circumferentially. As the tie rods rotate, the positive and negative threads on the tie rods and the nuts fixed in the bearing seats form a kinematic pair, causing symmetrical relative displacement between the upper and lower bearing seats, thus adjusting the center distance between the upper and lower bearing seats.

[0008] The structure of the screw-down mechanism and the drive capability of the roll gap adjustment mechanism of a conventional two-roll short-stress line mill are designed for static adjustment; that is, the position adjustment between the upper and lower chocks is performed when the mill is not feeding steel and is unloaded. Roll gap adjustment under unloaded conditions is performed in the following stages: ① Pre-adjustment of the center distance between the upper and lower chocks of the two-roll short-stress line mill in the mill's maintenance and assembly room; ② After the two-roll short-stress line mill is installed online, with no workpiece in the mill, precise adjustment of the roll gap and axial position between the upper and lower rolls is performed; ③ Fine-tune the roll gap and axial position between the upper and lower rolls after trial rolling based on a sample. Therefore, even when the mill is online, roll gap adjustment remains static.

[0009] The meaning of online load adjustment of the hold-down mechanism of the two-roll short stress line rolling mill is to instantly adjust the roll gap size between the upper and lower rolls under the condition of steel passing through the rolling mill to meet the shape and size accuracy control requirements of the rolled products passing through the rolling mill.

[0010] Online reduction adjustment under load requires minimal, instantaneous control. Therefore, achieving online reduction adjustment under load in short-stress line mills requires a strong, micro- and instantaneous adjustment capability for the mill's reduction mechanism. The operating characteristics of the reduction mechanism in conventional two-roll short-stress line mills indicate that the strength of the components in the closed force transmission chain for the workpiece, formed by the screw and nut between the upper and lower bearing blocks, which directly bear the rolling force, meets requirements. The static adjustment drive capability is sufficient, and the dynamic adjustment drive capability warrants further investigation. The structural characteristics of two-roll short-stress line mills indicate that the online reduction process requires minimal adjustment. The screw and nut, as the terminal elements in the reduction mechanism's transmission chain, require minimal relative rotation angle during online adjustment. Therefore, achieving online reduction adjustment under load in two-roll short-stress line mills requires addressing the key issues surrounding the roll gap adjustment drive mechanism, which generates relative displacement between the upper and lower bearing blocks in the reduction mechanism.

[0011] In order to achieve the online load-bearing pressure adjustment function of the two-roll short stress line rolling mill, the industry has attempted to increase the driving capacity of the roll gap adjustment drive mechanism to achieve the online load-bearing pressure adjustment function. The method is to basically remain unchanged in the structural composition and working principle of the tie rod mechanism, that is, the tie rod still serves as the screw, the force system between the tie rod and the upper and lower bearing seats is unchanged, and the structural relationship between the screw and nut motion pair is unchanged. The working principle of the upper and lower bearing seat center distance adjustment is still adopted, and the rotational drive capacity of the traditional roll gap adjustment mechanism is increased, that is, the rotational drive torque of the screw is increased. The strong driving torque is used to rotate the screw under load to achieve the purpose of real-time load adjustment of the roll gap.

[0012] Traditional short-stress line rolling mill screwdown mechanisms are designed to operate in a static adjustment mode. The mechanical transmission chain consisting of the screw, nut, and roll gap adjustment drive mechanism is long, with the screw and nut moving pairs at the end of the screwdown mechanism's transmission chain. Furthermore, due to the mechanical characteristics of the screw-nut transmission mechanism, the system exhibits significant inertia, making it difficult to control the relative positional accuracy of the screw and nut during rotation. During the on-the-fly adjustment of screwdown under load, transient dynamic processes of static and dynamic friction occur between the rod and nut friction pairs. Due to the significant difference in the dynamic and static friction coefficients of the screw and nut moving pairs, a sufficiently large power source is required to meet power input requirements. On-the-fly adjustment of screwdown involves a continuous start-stop process, consuming significant energy to accommodate the dynamic response of the transmission chain and resulting in significant lag in the adjustment response. Therefore, online on-load adjustment, achieved through relative rotation between the screw and nut and increased screw torque, suffers from poor dynamic characteristics and is not a preferred mechanism for on-the-fly adjustment of screwdown under load. Secondly, judging from the top space dimensions of the traditional two-roll short stress line rolling mill, without increasing the center distance of the mill bearing seat tie rods, simply increasing the capacity of the roll gap adjustment mechanism drive device is also difficult to meet the matching requirements of the roll gap adjustment drive device and the screw installation dimensions on both sides of the bearing seat; and after increasing the center distance of the mill bearing seat tie rods and coordinating the size of the entire machine, the weight of the entire machine increases rapidly, and at the same time it makes it difficult to coordinate with other equipment on the rolling line and requires adaptive transformation. Therefore, the economic efficiency is not good.

[0013] Therefore, in the two-roll short stress line rolling mill, since the upper and lower bearing seats of the pressure adjustment mechanism are simply connected by a tie rod nut, the functional conditions for online adjustment of the pressure reduction under load are not met. Summary of the Invention

[0014] In order to solve the above problems, the present invention provides a piston-mounted dual-mode adjustable load-down two-roller short stress line rolling mill.

[0015] In order to achieve the above-mentioned purpose, the present invention provides a piston-mounted double-mode adjustable load-down two-roller short stress line rolling mill, which comprises at least a frame, two upper bearing seats arranged oppositely on both sides of the upper roll, two lower bearing seats arranged oppositely on both sides of the lower roll, and a pull rod installed on the frame, wherein the upper and lower sections of the pull rod have forward and reverse threads; nuts are provided at positions corresponding to the threads in the upper and lower bearing seats.

[0016] A roll gap adjustment mechanism is arranged on the top of the two-roll short stress line rolling mill body; the roll gap adjustment mechanism is connected to the pull rod in a transmission manner, and the roll gap adjustment mechanism drives the pull rod to rotate forward or reverse to synchronously adjust the distance between the upper bearing seat and the lower bearing seat;

[0017] A accommodating stroke chamber is provided in the upper bearing seat at a position corresponding to the nut, and a hydraulic cylinder is provided in the accommodating stroke chamber; wherein the cylinder body of the hydraulic cylinder is installed in the accommodating stroke chamber, and the piston of the hydraulic cylinder is fixedly connected to the nut.

[0018] Furthermore, the accommodating stroke cavity is an annular cavity arranged corresponding to the nut, and the hydraulic cylinder is an annular hydraulic cylinder; the annular hydraulic cylinder sleeve is arranged on the outside of the pull rod, and the annular hydraulic cylinder is located below the nut.

[0019] Furthermore, the annular hydraulic cylinder is inverted; wherein, the upper end of the nut is provided with an annular edge outward; the piston is installed below the annular edge of the nut and fixed by bolts; the cylinder body is downwardly abutted against the bottom of the annular cavity.

[0020] Furthermore, the opening of the accommodating stroke chamber is provided with an upper cover, and more than two anti-rotation pins are provided on the nut; through holes are provided on the upper cover corresponding to the anti-rotation pins, and the anti-rotation pins are inserted into the through holes.

[0021] Furthermore, a three-section composite roller is installed between the two upper bearing seats and between the two lower bearing seats; the three-section composite roller includes: a tie rod, a roller sleeved on the tie rod, and roller shafts mounted on both sides of the roller;

[0022] The pull rod is an elastic element used to lock the three-section roller. The pull rod has a threaded head, a polished rod in the middle, a frustum transition structure on both sides of the middle, and a large round body at the tail for stopping and positioning.

[0023] A hydraulic nut is provided on the corresponding pull rod head;

[0024] The roller shaft is made of an integrally manufactured journal structure that cooperates with a multi-row rolling bearing and a truncated cone structure provided on the side of the journal near the roller, with a hollow structure inside; the hollow structure is for the pull rod 30 to pass through;

[0025] The outer envelope of the roller is a cylindrical structure; the middle of the inner profile of the roller is a cylindrical hole; the two ends are tapered hole structures that match the truncated cone of the roller shaft;

[0026] The pull rod works within the elastic deformation range, and is elastically deformed during the extension stroke of the hydraulic nut piston, and then released to lock the combined roller in a prestressed state.

[0027] The present invention is based on the traditional pull rod (screw), nut mechanism, and roll gap adjustment mechanism. A hydraulic cylinder for fine-tuning the center distance of the upper and lower bearing seats is superimposed in series in the pull rod and nut mechanism, forming a mechanism that can act on the upper and lower bearing seats on the same side and can be used in different process stages. The two sets of mechanisms can adjust the center distance of the upper and lower bearing seats respectively; it has dual-mode working conditions to solve the problem of instant load-bearing pressure and adjustment of the two-roll short stress line rolling mill.

[0028] The dual-mode adjustment load-down mechanism of the two-roll short stress line rolling mill has the following features:

[0029] ① Dual-mode independent adjustment function: screw and nut rotary transmission adjustment mode and hydraulic cylinder linear drive adjustment mode; the two sets of mechanisms can work independently; wide range of working conditions adaptability and flexible adjustment methods;

[0030] ② The hydraulic cylinder directly drives the small stroke adjustment function under load pressure, with low delay response and good dynamic characteristics;

[0031] ③ The two-roller short stress line rolling mill has small changes in the whole machine, small size, light weight and good economy;

[0032] ④ It has similar dimensions to traditional short stress line rolling mills of the same specifications and has good substitutability. It can be interchanged with traditional short stress line rolling mills of the same specifications on the same base; the rolling mill can be replaced under different process requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It shows the main components of the two-roll short stress line rolling mill and the positional relationship between various mechanisms, components and parts.

[0034] Figure 2 It shows the main components of the pull rod mechanism and the positional relationship between the components and parts.

[0035] Figure 3 It is a tie rod structure. L represents the left-hand thread part, R represents the right-hand thread part, and G represents the fixed part.

[0036] Figure 4 It shows the main components of the annular cylinder hydraulic cylinder and the positional relationship between its components and parts.

[0037] Figure 5It shows the main components of the upper nut assembly and the positional relationship between the various components and parts.

[0038] Figure 6 It is the cylinder assembly structure of an annular cylinder hydraulic cylinder.

[0039] Figure 7 The figure shows the positional relationship between the upper nut assembly and the annular cylinder hydraulic cylinder at two stroke positions. Figure 7 A is the positional relationship between the upper nut assembly and the annular cylinder hydraulic cylinder at one stroke position. Figure 7 B is the positional relationship between the upper nut assembly and the annular cylinder hydraulic cylinder at another stroke position.

[0040] Figure 8A The pull rod is rotated, and the upper and lower bearing seats are symmetrically coarsely adjusted to the far position.

[0041] Figure 8B The pull rod is rotated, and the upper and lower bearing seats are symmetrically coarsely adjusted to the close position.

[0042] Figure 8C Hydraulically driven, the lower bearing seat remains in position while the upper bearing seat is fine-tuned.

[0043] Figure 9 It shows the main components of the traditional pull rod mechanism and the positional relationship between the components and parts.

[0044] Figure 10 Shown is a schematic structural diagram of a new two-roll short stress rolling mill.

[0045] Figure 11 It is a schematic cross-sectional view of a two-roll short stress rolling mill.

[0046] Figure 12 Schematic diagram of the roller system being separated into parts. DETAILED DESCRIPTION

[0047] The present invention will be further described below with reference to the accompanying drawings.

[0048] The dual-mode operating conditions are as follows: the hold-down mechanism operates in both no-load and online-loaded modes. This means: ① Under no-load conditions, when there is no workpiece in the mill and the upper and lower rolls are not engaged in rolling, the hydraulic motor or motor-driven roll gap adjustment lever drives the mechanism to rotate the screw and nut relative to each other, pre-adjusting the upper and lower bearing seats symmetrically with respect to the rolling centerline. When the preset position is reached, the screw rotation mechanism stops. ② When there is workpiece in the upper and lower rolls of the mill and rolling is being carried out online, the hydraulic cylinders stacked in series on the levers operate. Under the action of the oil in the hydraulic cylinders, the relative position of the piston and the cylinder body fixed in the nut changes, enabling small-scale and micro-dynamic adjustment of the position of the upper bearing seat relative to the lower bearing seat of the mill.

[0049] As shown in the figure, the main parts of the two-roll short stress line rolling mill of the present invention are 1 roll gap adjustment mechanism, 2 pull rod mechanism, 3 operating side upper bearing seat, 4 operating side lower bearing seat, 5 upper roller, 6 transmission side upper bearing seat, 7 transmission side lower bearing seat, 8 lower roller, and 9 base.

[0050] The dual-mode reduction adjustment device of a two-roll short stress line rolling mill is mainly composed of a roll gap adjustment mechanism (Part 1) and a pull rod mechanism (Part 2).

[0051] The roll gap adjustment mechanism, located at the top of the two-high short-stress line mill, drives the rotation of the tie rods in the tie rod mechanism. An independent hydraulic motor drives four interlocking worm gear or gear transmissions. The final transmission element of the transmission mechanism is connected to the tie rods in the tie rod mechanism. When the hydraulic motor is driven, the tie rods in the four tie rod mechanisms in the mill rotate simultaneously.

[0052] The tie rod mechanism connects the upper and lower bearing seats (Parts 3 and 4) and adjusts the center distance between them. It primarily consists of the tie rod (Part 10), the upper cover assembly (Part 11), the stop pin (Part 12), the upper nut (Part 13), the screw (Part 14), the stop block (Part 15), the piston assembly (Part 16), the cylinder assembly (Part 17), the frame (Part 18), and the lower nut (Part 19). The piston assembly (Part 16) and the cylinder assembly (Part 17) form the annular hydraulic cylinder.

[0053] The upper part of the pull rod 10 in the pull rod mechanism is provided with a key connection structure connected to the final transmission part in the roll gap adjustment mechanism; the middle part is a polished rod structure, which passes through the frame of part 18 and is used for the intermediate reference positioning when the upper bearing seat of part 3 and the lower bearing seat of part 4 move; there are two sections of thread structures with different rotation directions at the upper and lower parts, which are used to connect with the upper nut of part 13 and the lower nut of part 19 respectively, forming a threaded motion pair.

[0054] In the pull rod mechanism, the upper cover assembly of component 10 is fixed to the top surface of the upper bearing seat of component 3; the anti-rotation pin of component 12 is inserted into the top surface of the upper nut of component 13 and passes through the hole structure of the upper cover assembly of component 10 to prevent the rotation of the nut of component 13. One end of the anti-rotation pin of component 12 is fixed, and the other end can move axially within the circular hole with which it cooperates.

[0055] In the pull rod mechanism, the cross-section of the nut on part 13 is a T-shaped structure with a threaded inner bore, which cooperates with the threaded structure on the upper part of the pull rod 10; the upper part of the T-shaped structure has a light hole and a screw hole; the screw hole is used to carry the screw of part 14 connecting the hydraulic cylinder piston; the cylindrical surface of the lower part of the T-shaped structure cooperates with the inner surface of the annular cylinder hydraulic cylinder.

[0056] In the pull rod mechanism, the upper nut of component 13 is fixed in the upper bearing seat of component 3 and prevented from circumferential rotation by the stop block of component 15. The lower nut of component 19 is fixed in the lower bearing seat of component 4 and prevented from rotating by the circumferential toothed structure and the stop block. The upper nut of component 13 and the lower nut of component 19 have thread structures with different rotation directions. The thread structures of the upper and lower sections of the pull rod of component 10, with different rotation directions, form a threaded kinematic pair with the upper nut of component 13 and the lower nut of component 19, respectively. When the pull rod of component 10 rotates, the upper nut of component 13 and the lower nut of component 19 are fixedly connected to the upper bearing seat of component 3 and the lower bearing seat of component 4, respectively, and thus move linearly in opposite directions, thereby driving the upper bearing seat of component 3 and the lower bearing seat of component 4 to move symmetrically in opposite directions, respectively, with respect to the frame of component 18. The direction of the movement of the upper bearing seat of component 3 and the lower bearing seat of component 4 is determined by the rotation direction of component 10.

[0057] In the drawbar mechanism, the annular hydraulic cylinder, primarily composed of the piston assembly (Part 16) and the cylinder assembly (Part 17), sits within the upper recessed structure of the bearing seat (Part 3), centered around the drawbar (Part 10). The piston assembly (Part 16) faces upward. The annular hydraulic cylinder is a plunger-type cylinder, and the lower portion of the cylinder assembly (Part 17) features an oil port for injecting and draining hydraulic oil into and out of the cavity. After extending, the piston assembly (Part 16) returns to the cylinder via an elastic damping body between the upper and lower bearing seats. The piston assembly (Part 16) of the annular hydraulic cylinder is fixedly connected by the screw (Part 14) and the upper portion of the nut T-shaped structure (Part 13). The bottom of the cylinder assembly (Part 17) contacts the bottom of the recessed structure above the bearing seat (Part 3), transmitting the relative displacement between the piston and cylinder body and the axial force of the drawbar (Part 10). When the nut on part 13 moves to a fixed position on the pull rod of part 10, the cavity of the cylinder assembly of part 17 in the annular hydraulic cylinder is filled with / exhausted with hydraulic oil, which can drive the upper bearing seat of part 3 to move slightly relative to the lower bearing seat of part 4. When the amount of hydraulic oil injected / exhausted into the cavity of the cylinder assembly of part 17 is small, the movement of the upper bearing seat of part 3 is micro-movement. Figure 2 It can be seen from the figure that when the annular cylinder hydraulic cylinder piston and the cylinder body have some relative displacement, the piston assembly of part 16 is fixedly connected to the upper part of the nut T-shaped structure of part 13 through the screw of part 14, and therefore moves with the pull rod of part 10. However, due to the small stroke of the annular cylinder hydraulic cylinder, when designed, under the maximum stroke state, the top of the nut T-shaped structure of part 13 does not interfere with the relevant position of the upper cover assembly of part 11.

[0058] Because in the pull rod mechanism, the pull rod of part 10 and the upper nut of part 13 and the lower nut of part 19 form a threaded motion pair, when the pull rod of part 10 rotates, the upper bearing seat of part 3 and the lower bearing seat of part 4 can be driven to move relative to each other without relying on the relative displacement of the piston and cylinder body of the annular cylinder hydraulic cylinder. The annular cylinder hydraulic cylinder does not rely on the rotation of the pull rod of part 10, and can also drive the upper bearing seat of part 3 to move relative to the lower bearing seat of part 4 only by the relative displacement of the piston and cylinder body. The two sets of mechanisms for driving the relative movement of the upper bearing seat of part 3 and the lower bearing seat of part 4 can act separately to realize the relative change of the upper bearing seat of part 3 and the lower bearing seat of part 4, and the movement of the upper bearing seat of part 3 and the lower bearing seat of part 4 drives the change of the roll gap of the upper and lower rollers, thereby achieving the purpose of adjusting the roll gap of the rollers.

[0059] In the aforementioned tie rod mechanism, the tie rod (10) forms a threaded kinematic pair with the upper nut (13) and the lower nut (19). This results in a long transmission chain and slow dynamic response, making it suitable for coarse roll gap adjustment under unloaded conditions. The annular hydraulic cylinder has a short stroke, and the roll gap adjustment mechanism it forms is used for fine roll gap adjustment. Because the annular hydraulic cylinder drives the relative motion of the piston assembly (16) and the cylinder assembly (17) by injecting and discharging hydraulic oil from the cylinder assembly cavity, the resulting roll gap adjustment mechanism has a short transmission chain and fast dynamic response, making it suitable for online, loaded reduction adjustment in two-roll, short-stress line mills.

[0060] 4. Specific application of dual-mode pressure adjustment mechanism

[0061] The specific application of the present invention will be described below with reference to the accompanying drawings.

[0062] ① As shown in Figure 8, after the two-roll short-stress line mill is assembled in the mill maintenance workshop, the upper bearing seat (Part 3) and the lower bearing seat (Part 4) are at their maximum relative distance (for example, roll gap 58mm + 58mm). In the annular hydraulic cylinder, a distance is left between the bottom of the piston assembly (Part 16) and the bottom of the cylinder assembly (Part 17) to ensure that there is no interference (for example, 5mm).

[0063] ② After the roller gap adjustment mechanism of part 1 is driven, the pull rod of part 10 rotates. Under the side effect of the threaded movement of the upper nut of part 13 and the lower nut of part 19, the upper bearing seat of part 3 and the lower bearing seat of part 4 are symmetrically moved toward or away from each other with the frame of part 18 as the center for coarse adjustment (for example: the roller gap spacing is 46mm+46mm, and the distance between the bottom surface of the piston assembly and the bottom surface of the cylinder assembly is 5mm);

[0064] ③ After the two-roll short stress line mill body is moved from the mill maintenance workshop to the rolling line pre-position, if the distance between the upper bearing seat and the lower bearing seat does not initially meet the requirements after rough adjustment, the roll gap adjustment mechanism of the starter 1 is further adjusted online to initially meet the roll gap requirements of the rolling process;

[0065] ④Online load test rolling. Start the annular cylinder hydraulic cylinder roll gap adjustment mechanism to make fine adjustments to the roll gap (for example: roll gap spacing 46mm+46mm, the distance between the bottom surface of the piston assembly and the bottom surface of the cylinder assembly is 8mm).

[0066] like Figures 10 to 12 As shown, the short stress line rolling mill body is mainly composed of an operating side bearing seat assembly 600, an upper rolling roll 25, a lower rolling roll 26, a transmission side bearing seat assembly 700, etc.

[0067] The operating side bearing seat assembly 600 is mainly composed of a pull rod mechanism 2, an operating side upper bearing seat 23, an operating side lower bearing seat 24, a frame 9, etc.; the operating side upper roller shaft 31, 34, the operating side lower roller shaft, the hydraulic nut 32, the locking anti-loosening nut 33, the upper roller cover 37, and the lower roller cover 38 are included in the operating side upper bearing seat 23 and the operating side lower bearing seat 24.

[0068] The transmission-side bearing seat assembly 700 mainly consists of a pull rod mechanism 2, a transmission-side upper bearing seat 26, a transmission-side lower bearing seat 27, and a frame 9. The transmission-side upper roller 35, the transmission-side lower roller 36, and two sets of pull rods 30 are contained in the transmission-side upper bearing seat 26 and the transmission-side lower bearing seat 27.

[0069] Hydraulic nut 32 is used to stretch tie rod 30 to meet the requirements of the roller system connection process during assembly and disassembly. It is a short-stroke, high-pressure plunger cylinder type with an operating pressure of no less than 65 MPa. It primarily consists of cylinder assembly 321 and piston assembly 322. Cylinder assembly 321 is an annular structure with a threaded outer cylindrical surface that mates with locking nut 33 and an inner cylindrical surface that mates with tie rod 30. The center portion comprises a high-pressure plunger cylinder structure. Hydraulic nut 32 utilizes a quick-connect coupling; during roller system assembly and disassembly, the hydraulic nut 32 is connected to the hydraulic source via the quick connector.

[0070] The locking nut 33 is used to prevent the three-stage roller system connection from loosening after the hydraulic nut 32 loses pressure. The locking nut 33 is an annular structure with a tool socket on the outer ring to help it rotate and a threaded inner cylindrical surface to cooperate with the hydraulic nut 32.

[0071] Tie rod 30 is an elastic element used to lock the three-section roll structure. It features a threaded head, a polished middle section, frustum-shaped transition structures on either side, and a large rounded end that acts as a stop. Tie rod 30 operates within its elastic deformation range. During the extension stroke of the 32-stage hydraulic nut piston, it elastically deforms and then releases, locking the assembled rolls in a prestressed state.

[0072] The upper operating-side bearing seat 23, the lower operating-side bearing seat 24, the upper transmission-side bearing seat 26, and the lower transmission-side bearing seat 27 respectively house the upper operating-side rollers 31 and 34, the lower operating-side rollers 35, and the lower transmission-side rollers 36 (hereinafter collectively referred to as "roller shafts"). The roller shafts are assembled into components, with internal sleeves, flanges, and other components. Each structural segment of the roller shaft's outer cylindrical surface is equipped with a journal structure and a truncated cone structure for mate- ing with multiple-row rolling bearings. The interior includes a hollow structure through which the tie rod 30 passes. The truncated cone structure of the roller shaft matches the shape and size of the tapered holes at the ends of the upper and lower rollers 25 and 28, enabling the three-section rollers to be connected and transmitting rolling torque and the bending moment generated when the rollers bear rolling force. A sealing ring groove is engraved on the large curved surface of the truncated cone structure for accommodating a sealing ring to seal between the roller shaft and the rollers, preventing the intrusion of cooling water during rolling. The hollow section of the operating-side roller shaft features a set of sleeves for guiding and roughly centering the head of the tie rod 30. The tail end of the drive-side roller shaft is a flat head structure that connects to the mill's universal coupling. Within the hollow section of the head are a set of sleeves and flanges for centering the tie rod 30 and preventing it from exiting the tail end of the drive-side roller shaft. The remainder of the roller shaft structure meets the structural requirements of the corresponding bearing seat components. The upper and lower rollers 25 and 28 are consumable parts of the steel rolling process and directly support the rolled product. The outer envelope of the upper and lower rollers 25 and 28 is a cylindrical structure. Upon delivery from the machinery factory, the steel mill engraves multiple sets of slots based on the rolling process. The inner profiles of the upper and lower rollers 25 and 28 feature a cylindrical hole in the middle, with tapered holes at each end. The tapered holes match the shape and dimensions of the frustum of the upper roller shaft head to transmit rolling torque.

[0073] The hydraulic nut 32, locking nut 33, operating-side upper bearing seat 23, operating-side upper roller shaft 31, upper roller 25, tie rod 30, transmission-side upper roller shaft 35, and transmission-side upper bearing seat 26 form a three-section upper roller system. The hydraulic nut 32, locking nut 33, operating-side lower bearing seat 24, operating-side lower roller shaft 34, lower roller 28, tie rod 30, transmission-side lower bearing seat 27, and transmission-side lower roller shaft 36 form a three-section lower roller system.

[0074] The operating side roller, rolling roller and transmission side roller are connected by the tie rod 30, hydraulic nut 32 and locking anti-loosening nut 33 to form a three-section roller system structure. When the tie rod 30 is in a prestressed state, it is a force-bearing working unit, which can withstand the bending moment generated by the rolling force while transmitting the rolling torque.

[0075] Taking the above roller system as an example, the operating side upper roller shaft 31 is fixed in the operating side upper bearing seat 23, the transmission side upper roller shaft 35 is fixed in the transmission side upper bearing seat 26, and the upper roller 25 is assembled between the operating side and transmission side roller shafts;

[0076] The head of the pull rod 30 passes through the hollow structure at the tail of the upper roller shaft 35 on the transmission side, and the large-head cylinder at the tail of the pull rod stops at the end face of the flat head structure of the roller shaft on the transmission side. It is centered and axially fixed by a group of sleeves and flanges inside the upper roller shaft 35 on the transmission side. Then, the head of the pull rod 30 passes through the upper roller 25 and the upper roller shaft 31 on the operating side in turn, and its head thread structure is exposed to the outside of the upper bearing seat 23 on the operating side. The locking step is performed by the hydraulic nut 32, and the locking anti-loosening nut 33 prevents loosening, thereby realizing the connection of the three-section structure of the roller system, which has high working reliability.

[0077] Because the three-stage structure of the roll system of the present invention utilizes a shaftless structure with a conical connection between the roller shaft and the rollers, and a tie rod 30 is used to lock the hollow structure, the rolls can be adaptively centered, reducing the difficulty of assembly and disassembly. The tie rod 30 is permanently fixed in the transmission-side upper bearing seat 26 and the transmission-side lower bearing seat 27, eliminating interference during the entire assembly and disassembly process. During assembly, the rolls are easily aligned. These convenient and reliable connections facilitate automated assembly of the mill body and online roll changing.

[0078] In summary, in the three-section combined structure rolling mill system, in the operating side bearing seat assembly 600 and the transmission side bearing seat assembly 700, the roller shaft and bearings of the bearing seat are always connected to the other parts of the bearing seat and fixed in position during operation, disassembly and assembly, and do not involve replacement, thus maintaining a good assembly structure and performance. Due to the reasonable structure, reliable operation, and few discrete parts for disassembly and assembly based on the combined roller two-roller short stress line rolling mill, disassembly and assembly are extremely simple and convenient, which can shorten the roll changing time and meet the conditions for online roll changing. Secondly, since the replacement parts only involve the rolls in the middle part of the roll system, the weight affecting the economic efficiency is small. Therefore, due to the small number of consumable parts, good economic efficiency is reflected.

Claims

1. A piston-mounted, dual-mode, load-adjustable, two-roller short-stress line rolling mill, comprising at least a frame, two upper bearing seats disposed oppositely on either side of the upper roll, two lower bearing seats disposed oppositely on either side of the lower roll, and a tie rod mounted on the frame, wherein the upper and lower sections of the tie rods have forward and reverse threads; nuts are disposed in the upper and lower bearing seats at positions corresponding to the threads. A roll gap adjustment mechanism is arranged on the top of the two-roll short stress line rolling mill body; the roll gap adjustment mechanism is connected to the pull rod in a transmission manner, and the roll gap adjustment mechanism drives the pull rod to rotate forward or reverse to synchronously adjust the distance between the upper bearing seat and the lower bearing seat; It is characterized by: A accommodating stroke chamber is provided in the upper bearing seat at a position corresponding to the nut, and a hydraulic cylinder is provided in the accommodating stroke chamber; wherein the cylinder body of the hydraulic cylinder is installed in the accommodating stroke chamber, and the piston of the hydraulic cylinder is fixedly connected to the nut; A three-section composite roller is installed between the two upper bearing seats and the two lower bearing seats; the three-section composite roller includes: a pull rod, a roller sleeved on the pull rod, and a roller shaft mounted on both sides of the roller; The pull rod is an elastic element used to lock the three-section structure roller; the pull rod head is a threaded structure, the middle part is a polished rod structure, the two sides of the middle are frustum transition structures, and the tail is a large round body used for stop positioning; A hydraulic nut is provided on the corresponding pull rod head; The roller shaft is composed of an integrally manufactured journal structure matched with a multi-row rolling bearing and a truncated cone structure arranged on the side of the journal near the roller, with a hollow structure inside; the hollow structure is for the pull rod to pass through; The outer envelope of the roller is a cylindrical structure; the middle of the inner profile of the roller is a cylindrical hole; the two ends are tapered hole structures that match the truncated cone of the roller shaft; The pull rod works within the elastic deformation range, and is elastically deformed during the extension stroke of the hydraulic nut piston, and then released to lock the combined roller in a prestressed state.

2. The piston-mounted dual-mode adjustable load-down two-roller short stress line rolling mill according to claim 1, characterized in that: The accommodating stroke cavity is an annular cavity arranged corresponding to the nut, and the hydraulic cylinder is an annular hydraulic cylinder; the annular hydraulic cylinder sleeve is arranged on the outside of the pull rod, and the annular hydraulic cylinder is located below the nut.

3. The piston-mounted dual-mode adjustable load-down two-roller short stress line rolling mill according to claim 2, characterized in that: The annular hydraulic cylinder is inverted; wherein, the upper end of the nut is formed with an annular edge outward; the piston is installed below the annular edge of the nut and fixed by bolts; the cylinder body is downwardly abutted against the bottom of the annular cavity.

4. The piston-mounted dual-mode adjustable load-down two-roller short stress line rolling mill according to claim 2, characterized in that: The opening of the accommodating stroke chamber is provided with an upper cover, and more than two anti-rotation pins are provided on the nut; through holes are provided on the upper cover corresponding to the anti-rotation pins, and the anti-rotation pins are inserted into the through holes.

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