Quick-change rack

Abstract

The utility model provides a quick-change rack, which belongs to the technical field of steel pipe forming and comprises a universal base, a moving mechanism and a forming mechanism, and a sliding rail, a positioning structure and a pressing structure are arranged on the universal base; the moving mechanism comprises a moving vertical frame, a sliding block arranged at the bottom of the moving vertical frame, a driving element, an upper roller connecting shaft and a lower roller connecting shaft. Sliding blocks at the bottoms of the movable vertical frames are in sliding fit with the sliding rails; the forming mechanism comprises a bottom plate and a forming vertical frame fixed on the bottom plate, and the forming vertical frame is provided with an upper roll shaft and a lower roll shaft; the bottom plate is limited on the universal base through the positioning structure and the pressing structure; the upper roll shaft is coaxially connected or disconnected with the upper roll connecting shaft through an upper coupler, and the lower roll shaft is coaxially connected or disconnected with the lower roll connecting shaft through a lower coupler. The quick-change rack provided by the utility model can realize quick change when square tubes with different specifications are formed, the change mode is time-saving and labor-saving, the influence on a production line is reduced, the production efficiency can be ensured, and the forming precision can also be ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of steel pipe forming, and particularly relates to a quick-change rack. Background Art

[0002] Steel pipes are usually formed by bending strip steel, and multiple sets of forming racks are usually used in the production process of steel pipes. The forming size of the steel pipe is determined by the extrusion rollers on the forming roller rack. Especially in the subsequent sizing section, it is used to shape the final forming size of the steel pipe.

[0003] The square pipe forming production line generally uses direct cold rolling forming of strip steel. Since there are four included angles in the square steel pipe, it needs to go through multiple processes such as strip steel feeding, strip steel leveling, rough forming, single-side forming, extrusion forming, and welding. The formed square pipe needs to be sized and shaped into the final product; the forming difficulty is high, and each process must have high accuracy, otherwise it is difficult to ensure the dimensional accuracy of the final square pipe.

[0004] Since square pipes have multiple models and multiple pipe diameters, when producing different products each time, either multiple production lines with different specifications and models need to be established, or different forming rollers need to be replaced. Establishing production lines with different specifications and models greatly increases the processing cost of steel pipe production; when replacing different forming rollers, since a steel pipe requires multiple sets of forming racks for rough forming, single-side forming, and extrusion forming, when replacing, all the forming rollers in each forming rack need to be replaced, which is difficult to operate, takes a long time to replace, and after replacement, work such as rack resetting, debugging, and inspection is required, which also takes more time and is difficult to ensure the forming accuracy of the rack.

[0005] Therefore, the current forming rack needs to replace the corresponding forming rollers according to the size of the square pipe, which takes a long time, is time-consuming and laborious, causes many inconveniences to production, and is also difficult to ensure the forming accuracy. Summary of the Utility Model

[0006] An embodiment of the utility model provides a quick-change rack, aiming to solve the problems that replacing the forming roller is time-consuming and laborious and the accuracy is difficult to guarantee.

[0007] To achieve the above object, the technical solution adopted by the present utility model is as follows: A quick-change rack is provided, which includes a general base, a moving mechanism, and a forming mechanism. A slide rail, a positioning structure, and a pressing structure are provided on the general base; the moving mechanism includes a moving vertical frame, a slider provided at the bottom of the moving vertical frame, a driving element for driving the movement of the moving vertical frame, an upper roller connecting shaft and a lower roller connecting shaft provided on the moving vertical frame; the slider at the bottom of the moving vertical frame is in sliding fit with the slide rail; the forming mechanism includes a bottom plate and a forming vertical frame fixed on the bottom plate. An upper roller shaft and a lower roller shaft are sequentially arranged on the forming vertical frame from top to bottom. The upper roller shaft is coaxially connected to the upper roller connecting shaft through an upper coupling, and the lower roller shaft is coaxially connected to the lower roller connecting shaft through a lower coupling; the bottom plate is limited on the general base through the positioning structure and the pressing structure;

[0008] The driving element drives the moving vertical frame to move along the slide rail close to or away from the forming vertical frame, so that the upper roller shaft is coaxially connected to or disconnected from the upper roller connecting shaft through the upper coupling, and the lower roller shaft is coaxially connected to or disconnected from the lower roller connecting shaft through the lower coupling.

[0009] In an implementable manner, the upper coupling includes a first upper half coupling and a matching second upper half coupling. First guiding inclined surfaces are provided on both sides of the end of the engaging claw of the first upper half coupling, and second guiding inclined surfaces are provided on both sides of the end of the engaging claw of the second upper half coupling; when the first upper half coupling is connected to the second upper half coupling, self-aligning engagement of the upper coupling is achieved through the cooperation of the first guiding inclined surface and the second guiding inclined surface; wherein, the first upper half coupling and the second upper half coupling are respectively connected to the upper roller connecting shaft and the upper roller shaft;

[0010] The structure of the lower coupling is the same as that of the upper coupling.

[0011] In an implementable manner, the moving mechanism further includes a first lifting mechanism and a first moving bearing seat connected to the first lifting mechanism. The first lifting mechanism is installed on the top of the moving vertical frame, the upper roller connecting shaft is rotatably installed on the first moving bearing seat, and the first lifting mechanism drives the upper roller connecting shaft to lift and adjust through the first moving bearing seat;

[0012] The forming mechanism further includes a second lifting mechanism and a second moving bearing seat connected to the second lifting mechanism. The second lifting mechanism is installed on the top of the forming vertical frame, the upper roller shaft is rotatably installed on the second moving bearing seat, and the second lifting mechanism drives the upper roller shaft to lift and adjust through the second moving bearing seat.

[0013] In an implementable manner, an alignment and calibration structure for aligning the first upper half coupling and the second upper half coupling is further provided between the movable upright frame and the forming upright frame. The alignment and calibration structure includes a second positioning plate fixed to the second movable bearing seat, a first positioning plate fixed to the first movable bearing seat, and a positioning wheel fixed to the first positioning plate. The height of the first positioning plate is higher than that of the second positioning plate. When the first positioning plate descends with the first lifting mechanism until the positioning wheel supports on the second positioning plate, the axes of the first upper half coupling and the second upper half coupling are aligned, and the positioning wheel moves along the top surface of the second positioning plate as the movable upright frame moves.

[0014] In an implementable manner, an upper core shaft is further provided at one end of the upper roller shaft facing the movable upright frame. The upper core shaft is coaxial with and integrally formed with the upper roller shaft. The upper core shaft is located at the center of the second upper half coupling and extends out of the second upper half coupling along the axis direction of the upper roller shaft. When the upper couplings are connected, the upper core shaft extends into the first upper half coupling. A lower core shaft is provided on the lower roller shaft.

[0015] In an implementable manner, multiple groups of the forming upright frames are arranged on the bottom plate along the moving direction of the steel pipe forming, and multiple groups of the moving mechanisms corresponding to the forming upright frames one by one are provided on the universal base.

[0016] In an implementable manner, pressing structures for pressing on the bottom plate are respectively provided on the front and rear sides of the universal base. The pressing structure includes a rotating upright plate rotatably connected to the universal base and a pressing screw that can be adjusted to press on the bottom plate from top to bottom. A bending plate is provided at the top of the rotating upright plate, and the pressing screw is screwed on the bending plate.

[0017] In an implementable manner, a pressing block is provided at the lower end of the pressing screw, and the bottom area of the pressing block is larger than the diameter of the pressing screw.

[0018] In an implementable manner, the pressing structure further includes a horizontal tightening screw horizontally abutted against the side surface of the bottom plate, and the horizontal tightening screw is screwed on the rotating upright plate.

[0019] In an implementable manner, the positioning structures are respectively provided on three sides of the universal base. The positioning structure includes a fixed positioning seat fixed to the universal base, and the fixed positioning seat performs three-sided positioning on the bottom plate.

[0020] The quick-change rack provided by the present utility model has the following beneficial effects compared with the prior art: A universal base is designed. When square tubes of different specifications need to be formed, the forming mechanism is hoisted as a whole onto the universal base, and is pressed and positioned by the positioning structure and the pressing structure. Then, the driving moving mechanism is moved towards the forming mechanism, so that the upper roller shaft is coaxially connected to the upper roller connecting shaft through the upper coupling, and the lower roller shaft is coaxially connected to the lower roller connecting shaft through the lower coupling. Thus, the power mechanism connected to the upper roller connecting shaft and the lower roller connecting shaft can drive the upper roller shaft and the lower roller shaft to rotate for square tube forming work. In this process, since the forming mechanism is an integral structure and there is no need to temporarily replace the forming rollers on the upper roller shaft and the lower roller shaft, quick replacement when forming square tubes of different specifications can be achieved. This replacement method saves time and effort, not only reducing the labor intensity but also not delaying normal production; since the forming mechanism is integral, the forming accuracy can also be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic perspective structure of the quick-change rack provided by an embodiment of the present utility model Figure 1 ;

[0022] Figure 2 Schematic perspective structure of the quick-change rack provided by an embodiment of the present utility model Figure 2 ;

[0023] Figure 3 Schematic side view structure of the quick-change rack provided by an embodiment of the present utility model (coupling connection state);

[0024] Figure 4 Schematic top view structure of the quick-change rack provided by an embodiment of the present utility model;

[0025] Figure 5 is the sectional view along Figure 4 line A-A in

[0026] Figure 6 Schematic structure diagram of the quick-change rack provided by an embodiment of the present utility model with the coupling not connected;

[0027] Figure 7 Schematic perspective structure of a set of quick-change racks provided by an embodiment of the present utility model Figure 1 ;

[0028] Figure 8 Schematic perspective structure of a set of quick-change racks provided by an embodiment of the present utility model Figure 2 ;

[0029] Figure 9 Schematic perspective structure diagram of the bottom plate and the universal base of the quick-change rack provided by an embodiment of the present utility model;

[0030] Figure 10 Schematic perspective view of the universal base provided by the embodiment of the present utility model;

[0031] Explanation of reference numerals:

[0032] 1, forming vertical frame; 2, moving vertical frame; 3, driving element; 4, slide rail; 5, slider; 6, universal base; 7, positioning structure; 8, pressing structure; 81, pressing screw; 82, rotating vertical plate; 83, horizontal pressing screw; 9, lifting lug; 10, bottom plate; 11, lower roller shaft; 12, upper roller shaft; 13, second lifting mechanism; 14, first lifting mechanism; 15, second positioning plate; 16, first positioning plate; 17, upper coupling; 18, lower coupling; 19, lower roller connecting shaft; 20, upper roller connecting shaft; 21, positioning wheel; 22, upper mandrel; 23, lower mandrel; 24, first guiding inclined surface; 25, second guiding inclined surface. Detailed implementation manners

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0034] In the claims, description and above-mentioned accompanying drawings of the present utility model, unless otherwise clearly defined, when using terms such as "first", "second" or "third", etc., they are all used to distinguish different objects and are not used to describe a specific order.

[0035] Please refer to Figures 1 to 10 simultaneously. Now, the quick-change rack provided by the present utility model will be described. The quick-change rack includes a universal base 6, a moving mechanism and a forming mechanism. A slide rail 4, a positioning structure 7 and a pressing structure 8 are provided on the universal base 6; the moving mechanism includes a moving vertical frame 2, a slider 5 provided at the bottom of the moving vertical frame 2, a driving element 3 for driving the moving vertical frame 2 to move, an upper roller connecting shaft 20 and a lower roller connecting shaft 19 provided on the moving vertical frame 2; the slider 5 at the bottom of the moving vertical frame 2 is in sliding fit with the slide rail 4; the forming mechanism includes a bottom plate 10 and a forming vertical frame 1 fixed on the bottom plate 10. An upper roller shaft 12 and a lower roller shaft 11 are sequentially arranged on the forming vertical frame 1 from top to bottom. The upper roller shaft 12 is coaxially connected to the upper roller connecting shaft 20 through an upper coupling 17, and the lower roller shaft 11 is coaxially connected to the lower roller connecting shaft 19 through a lower coupling 18; the bottom plate 10 is limited on the universal base 6 through the positioning structure 7 and the pressing structure 8; the driving element 3 drives the moving vertical frame 2 to move along the slide rail 4 closer to or away from the forming vertical frame 1, so that the upper roller shaft 12 is coaxially connected to or disconnected from the upper roller connecting shaft 20 through the upper coupling 17, and the lower roller shaft 11 is coaxially connected to or disconnected from the lower roller connecting shaft 19 through the lower coupling 18.

[0036] The quick-change machine frame provided by the present utility model, compared with the prior art, has the beneficial effects that: a universal base 6 is designed. When forming square tubes of different specifications, the forming mechanism is hoisted onto the universal base 6 as a whole, and is pressed and positioned by the positioning structure 7 and the pressing structure 8. Then, the driving moving mechanism is driven to move towards the forming mechanism, so that the upper roller shaft 12 is coaxially connected to the upper roller connecting shaft 20 through the upper coupling 17, and the lower roller shaft 11 is coaxially connected to the lower roller connecting shaft 19 through the lower coupling 18. Then, the power mechanism connected to the upper roller connecting shaft 20 and the lower roller connecting shaft 19 can drive the upper roller shaft 12 and the lower roller shaft 11 to rotate to perform the square tube forming work. In this process, since the forming mechanism is an integral structure and there is no need to temporarily replace the forming rollers on the upper roller shaft 12 and the lower roller shaft 11, the quick replacement when forming square tubes of different specifications can be realized. This replacement method saves time and effort, not only reduces the labor intensity, but also does not delay the normal production; since the forming mechanism is integral, the forming accuracy can also be guaranteed.

[0037] The moving mechanism connects a power source to the forming mechanism. The power source can be a reducer motor, and is connected to the main shaft of the reducer motor through the upper roller connecting shaft 20 and the lower roller connecting shaft 19 to realize the driving of the upper roller shaft 12 and the lower roller shaft 11. Among them, the extrusion rollers are respectively installed on the upper roller shaft 12 and the lower roller shaft 11. When the forming mechanism needs to be replaced, the driving element 3 drives the moving stand 2 to move backward, the upper roller connecting shaft 20 is disconnected from the upper roller shaft 12, and the lower roller connecting shaft 19 is disconnected from the lower roller shaft 11. After the forming stand 1 is hoisted onto the universal base 6 and fixed, the driving element 3 drives the moving stand 2 to move forward, and the upper roller connecting shaft 20 is connected to the upper roller shaft 12, and the lower roller connecting shaft 19 is connected to the lower roller shaft 11.

[0038] The reason for being able to guarantee the forming accuracy is that the forming mechanism is a complete set of structures. The upper roller shaft 12, the lower roller shaft 11 and the installed extrusion rollers have been debugged before the quick change, and the accuracy is guaranteed. Moreover, it does not need to be installed on the production line for debugging. In this way, there is time for installation and debugging work on the non-production line, and there is no need to stop the production line for debugging. Therefore, the production efficiency is greatly improved, and the forming accuracy is also improved.

[0039] Among them, the driving element 3 is fixed on the universal base 6, and it can be a linear actuator such as a cylinder, a hydraulic cylinder or an electric push rod.

[0040] In order to facilitate the hoisting of the forming mechanism, four lifting lugs 9 are arranged on the bottom plate 10, or the lifting lugs 9 can also be arranged on the forming stand 1.

[0041] In some embodiments, see Figures 2 to 8As shown, the upper coupling 17 includes a first upper half coupling and a mating second upper half coupling. On both sides of the end of the engaging claw of the first upper half coupling, there are first guiding inclined surfaces 24, and on both sides of the end of the engaging claw of the second upper half coupling, there are second guiding inclined surfaces 25. When the first upper half coupling is connected to the second upper half coupling, the self-aligning engagement of the upper coupling 17 is achieved through the cooperation of the first guiding inclined surface 24 and the second guiding inclined surface 25. Among them, the first upper half coupling and the second upper half coupling are respectively connected to the upper roll connecting shaft 20 and the upper roll shaft 12. Through the provided guiding inclined surfaces, when the moving stand 2 approaches the forming stand 1, no matter which position of the second upper half coupling the first guiding inclined surface 24 contacts, it will rotate and be guided into the second upper half coupling under the cooperation of the guiding inclined surfaces, realizing the connection of the upper coupling 17. This process does not require manual intervention for alignment and can achieve the function of self-aligning and self-connecting.

[0042] The structure of the lower coupling 18 is the same as that of the upper coupling 17. Since the two couplings are connected simultaneously, the specific structure of the lower coupling 18 is not marked in the figure.

[0043] In some embodiments, referring to Figures 2 to 8 As shown, the moving mechanism further includes a first lifting mechanism 14 and a first moving bearing block connected to the first lifting mechanism 14. The first lifting mechanism 14 is installed at the top of the moving stand 2, and the upper roll connecting shaft 20 is rotatably installed on the first moving bearing block. The first lifting mechanism 14 drives the upper roll connecting shaft 20 to move up and down through the first moving bearing block for adjustment. The forming mechanism further includes a second lifting mechanism 13 and a second moving bearing block connected to the second lifting mechanism 13. The second lifting mechanism 13 is installed at the top of the forming stand 1, and the upper roll shaft 12 is rotatably installed on the second moving bearing block. The second lifting mechanism 13 drives the upper roll shaft 12 to move up and down through the second moving bearing block for adjustment. Specifically, the lifting mechanism can drive the two opposite upper half couplings to move up and down respectively, thereby adjusting the coaxiality of the upper roll connecting shaft 20 and the upper roll shaft 12, ensuring their coaxiality, and realizing the effective transmission of power.

[0044] In some embodiments, referring to Figures 2 to 8As shown, an alignment calibration structure for aligning the first upper half coupling and the second upper half coupling is also provided between the mobile stand 2 and the forming stand 1. The alignment calibration structure includes a second positioning plate 15 fixed to the second mobile bearing seat, a first positioning plate 16 fixed to the first mobile bearing seat, and a positioning wheel 21 fixed to the first positioning plate 16; the height of the first positioning plate 16 is higher than the second positioning plate 15. When the first positioning plate 16 is lowered with the first lifting mechanism 14 until the positioning wheel 21 is supported on the second positioning plate 15, the axis of the first upper half coupling is aligned with the axis of the second upper half coupling, and the positioning wheel 21 moves along the top surface of the second positioning plate 15 with the movement of the mobile stand 2. This embodiment solves the problem of how to determine the alignment of the upper roller connecting shaft 20 and the upper roller shaft 12. Through the calibration of the alignment calibration structure, no human participation is required in the alignment process, thereby reducing the human error of manual operation.

[0045] Specifically, after the forming stand 1 is installed and positioned as a whole on the universal base 6, the upper roller shaft 12 on the forming stand 1 has been adjusted into place. At this time, with the upper roller shaft 12 as a reference, the upper roller connecting shaft 20 is moved downward by the first lifting mechanism 14. When the positioning wheel 21 abuts against the second positioning plate 15, it means that the upper roller connecting shaft 20 is coaxial with the upper roller shaft 12 and is at the same height. Then, the moving stand 2 is moved closer to the forming stand 1 through the driving element 3. At this time, the positioning wheel 21 moves along the top surface of the second positioning plate 15 until the upper coupling 17 is connected together.

[0046] In some embodiments, see Figures 5 to 6 As shown, an upper mandrel 22 is also provided at one end of the upper roller shaft 12 facing the movable stand 2. The upper mandrel 22 is coaxial with the upper roller shaft 12 and is an integral structure. The upper mandrel 22 is located at the center of the second upper half coupling, and the upper mandrel 22 extends out of the second upper half coupling along the axial direction of the upper roller shaft 12; when the upper coupling 17 is connected, the upper mandrel 22 extends into the first upper half coupling; a lower mandrel 23 is provided on the lower roller shaft 11. The purpose of the design of this embodiment is to fine-tune the synchronization of the upper roller connecting shaft 20 and the upper roller shaft 12. After the upper coupling 17 is fully connected, if the forming roller needs to be fine-tuned in the height direction, then at this time, relying solely on the meshing of the upper coupling 17, due to the existence of a certain gap between the mutual meshing, synchronous lifting and lowering cannot be formed. The use of the upper mandrel 22 can strengthen the integrity of the upper coupling 17, thereby realizing the synchronous lifting and lowering of the two upper half couplings and the upper roller shaft and the upper roller connecting shaft.

[0047] Similarly, the lower core shaft 23 provided on the lower roller shaft 11 can also extend into the first lower half coupling, which is equivalent to adding a connecting keel to the lower coupling 18, but does not hinder the function of the coupling.

[0048] In some embodiments, see Figure 1 and Figure 2As shown, there are multiple sets of forming upright frames 1 arranged on the bottom plate 10 along the moving direction of the steel pipe forming, and multiple sets of moving mechanisms corresponding to the forming upright frames 1 are arranged on the general base 6. For example, multiple finishing roll frames are arranged in a row and fixed on the bottom plate 10, and can be quickly changed to the general base 6 at one time by hoisting, which can not only ensure the matching accuracy between the finishing roll frames, but also greatly reduce the impact on the production line.

[0049] In some embodiments, referring to Figure 9 and Figure 10 , pressing structures 8 for pressing on the bottom plate 10 are respectively arranged on the front and rear sides of the general base 6; the pressing structure 8 includes a rotating vertical plate 82 rotatably connected to the general base 6 and a pressing screw 81 that can be adjusted to press on the bottom plate 10 from top to bottom. A bending plate is arranged at the top of the rotating vertical plate 82, and the pressing screw 81 is screwed on the bending plate. Another structural support for the quick change of the forming mechanism in this embodiment is that the bottom plate 10 of the forming mechanism does not need to be directly fixed by bolts, and there is no need to fix bolts one by one, which also avoids the time for screwing bolts. For the fixation of the forming mechanism, after rotating the rotating vertical plate 82 upwards, the bottom plate 10 can be pressed by using the pressing screw 81 to realize the positioning of the bottom plate 10 in the up and down direction.

[0050] In some embodiments, referring to Figure 9 and Figure 10 , a pressing block is arranged at the lower end of the pressing screw 81, and the bottom area of the pressing block is larger than the diameter of the pressing screw 81. By increasing the contact area between the pressing block and the bottom plate 10, the firmness of the pressing of the bottom plate 10 is improved.

[0051] In some embodiments, referring to Figure 9 and Figure 10 , the pressing structure 8 further includes a horizontal tightening screw 83 horizontally abutted against the side surface of the bottom plate 10, and the horizontal tightening screw 83 is screwed on the rotating vertical plate 82. The horizontal tightening screw 83 positions the forming mechanism in the front and rear directions.

[0052] It should be noted that the front in this article refers to one side of the forming mechanism, and the rear refers to one side of the moving mechanism. In this application, a set of pressing structures 8 are respectively arranged at both ends of the front side and the rear side of the general base 6.

[0053] In some embodiments, referring to Figure 9 and Figure 10, positioning structures 7 are respectively provided on three sides of the general base 6. The positioning structure 7 includes a fixed positioning seat fixed on the general base 6 formed by square tube extrusion. The fixed positioning seat performs three-sided positioning on the bottom plate 10. This application is for three-sided fixed positioning. Specifically, the three sides refer to the front side, the rear side, and the side in the square tube forming direction, that is, the positioning structure 7 is not provided on the side where the square tube enters the forming mechanism. Because in the square tube forming direction, the forming upright frame 1 will receive the impact force of the square tube moving in the forming direction, which will make the forming upright frame 1 have a tendency to move backward with the square tube. Therefore, the forming upright frame 1 and the bottom plate 10 will not move in the reverse direction. Therefore, it is sufficient to provide the positioning structure 7 on three sides of the bottom plate 10.

[0054] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0055] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A quick-change rack, characterized in that: include: A universal base (6) is provided with a slide rail (4), a positioning structure (7) and a pressing structure (8); The moving mechanism comprises a moving frame (2), a slider (5) arranged at the bottom of the moving frame (2), a driving element (3) for driving the moving frame (2) to move, an upper roller connecting shaft (20) and a lower roller connecting shaft (19) arranged on the moving frame (2); the slider (5) at the bottom of the moving frame (2) is slidably matched with the slide rail (4); and A forming mechanism comprises a base plate (10) and a forming stand (1) fixed on the base plate (10), wherein the forming stand (1) is provided with an upper roller shaft (12) and a lower roller shaft (11) in sequence from top to bottom, wherein the upper roller shaft (12) is coaxially connected to the upper roller connecting shaft (20) via an upper coupling (17), and the lower roller shaft (11) is coaxially connected to the lower roller connecting shaft (19) via a lower coupling (18); the base plate (10) is limited on the universal base (6) via the positioning structure (7) and the clamping structure (8); The driving element (3) drives the movable stand (2) to move along the slide rail (4) toward or away from the forming stand (1), so that the upper roller shaft (12) is coaxially connected or disconnected with the upper roller connecting shaft (20) through the upper coupling (17), and the lower roller shaft (11) is coaxially connected or disconnected with the lower roller connecting shaft (19) through the lower coupling (18).

2. The quick-change rack according to claim 1, characterized in that: The upper coupling (17) comprises a first upper half coupling and a matching second upper half coupling, wherein both sides of the end of the engaging claw of the first upper half coupling are provided with first guiding bevels (24), and both sides of the end of the engaging claw of the second upper half coupling are provided with second guiding bevels (25); when the first upper half coupling is connected to the second upper half coupling, the self-aligning engagement of the upper coupling (17) is achieved through the matching of the first guiding bevels (24) and the second guiding bevels (25); wherein the first upper half coupling and the second upper half coupling are respectively connected to the upper roller connecting shaft (20) and the upper roller shaft (12); The structure of the lower coupling (18) is the same as that of the upper coupling (17).

3. The quick-change rack according to claim 2, characterized in that: The moving mechanism further comprises a first lifting mechanism (14) and a first movable bearing seat connected to the first lifting mechanism (14); the first lifting mechanism (14) is installed on the top of the moving stand (2); the upper roller connecting shaft (20) is rotatably installed on the first movable bearing seat; the first lifting mechanism (14) drives the upper roller connecting shaft (20) to be lifted and lowered through the first movable bearing seat; The forming mechanism also includes a second lifting mechanism (13) and a second movable bearing seat connected to the second lifting mechanism (13); the second lifting mechanism (13) is installed on the top of the forming stand (1); the upper roller shaft (12) is rotatably installed on the second movable bearing seat; the second lifting mechanism (13) drives the upper roller shaft (12) to rise and fall through the second movable bearing seat.

4. The quick-change rack according to claim 3, characterized in that: An alignment and calibration structure for aligning the first upper half coupling and the second upper half coupling is also provided between the movable stand (2) and the forming stand (1), and the alignment and calibration structure comprises a second positioning plate (15) fixed to the second movable bearing seat, a first positioning plate (16) fixed to the first movable bearing seat, and a positioning wheel (21) fixed to the first positioning plate (16); the height of the first positioning plate (16) is higher than that of the second positioning plate (15), and when the first positioning plate (16) is lowered with the first lifting mechanism (14) to the position where the positioning wheel (21) is supported on the second positioning plate (15), the axis of the first upper half coupling is aligned with the axis of the second upper half coupling, and the positioning wheel (21) moves along the top surface of the second positioning plate (15) with the movement of the movable stand (2).

5. The quick-change rack according to claim 2, characterized in that: An upper core shaft (22) is also provided at one end of the upper roller shaft (12) facing the movable stand (2). The upper core shaft (22) is coaxial with the upper roller shaft (12) and is an integral structure. The upper core shaft (22) is located at the center of the second upper half coupling, and the upper core shaft (22) extends out of the second upper half coupling along the axial direction of the upper roller shaft (12); when the upper coupling (17) is connected, the upper core shaft (22) extends into the first upper half coupling; a lower core shaft (23) is provided on the lower roller shaft (11).

6. The quick-change rack according to claim 1, characterized in that: A plurality of groups of the forming frames (1) are arranged on the bottom plate (10) along the steel pipe forming moving direction, and a plurality of groups of the moving mechanisms corresponding one to one with the forming frames (1) are arranged on the universal base (6).

7. The quick-change rack according to claim 1, characterized in that: The front and rear sides of the universal base (6) are respectively provided with the clamping structure (8) for clamping on the bottom plate (10); the clamping structure (8) comprises a rotating vertical plate (82) rotatably connected to the universal base (6) and a clamping screw (81) that can be adjusted from top to bottom to clamp on the bottom plate (10); a bending plate is provided on the top of the rotating vertical plate (82), and the clamping screw (81) is screwed on the bending plate.

8. The quick-change rack according to claim 7, characterized in that: A pressing block is provided at the lower end of the pressing screw (81), and the bottom area of ​​the pressing block is larger than the diameter of the pressing screw (81).

9. The quick-change rack according to claim 7, characterized in that: The clamping structure (8) further comprises a horizontal tightening screw (83) which is horizontally pressed against the side surface of the bottom plate (10), and the horizontal tightening screw (83) is screwed onto the rotating vertical plate (82).

10. The quick-change rack according to claim 1, characterized in that: The three sides of the universal base (6) are respectively provided with the positioning structure (7), and the positioning structure (7) comprises a fixed positioning seat fixed on the universal base (6), and the fixed positioning seat forms a three-side positioning for the bottom plate (10).

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