A traction device for a blown film machine

Abstract

This invention relates to the field of thin film production and processing technology, specifically to a traction device for a blown film machine, comprising a base, a herringbone frame, and a traction system. The traction system includes a lower positioning guide roller, a frame, a multi-angle traction mechanism, and a servo motor. The lower positioning guide roller is horizontally installed in the middle of the base; an upper positioning guide roller is installed in the middle of the frame; two sets of multi-angle traction mechanisms are respectively positioned on both sides of the base; two sets of servo motors are respectively installed at both ends of the frame. This invention, through the two sets of multi-angle traction mechanisms, can achieve stepless and precise adjustment of the horizontal rotation and vertical tilt angle of the traction clamping roller, flexibly adjust the three-dimensional spatial posture of the traction clamping roller, and generate multi-directional traction force, which can effectively relieve the residual vertical internal stress after the film bubble cools and closes; at the same time, the traction clamping roller adopts a spatial three-dimensional cross structure design, which can form a three-dimensional clamping constraint force, thus possessing good spatial limiting and reverse correction effects.

Description

Technical Field

[0001] This invention relates to the field of thin film production and processing technology, specifically to a traction device for a blown film machine. Background Technology

[0002] In the film blowing machine production process, the film bubble, after being extruded and cooled by the die head, needs to rely on the traction mechanism to complete key processes such as flattening and guiding, smoothing and wrinkle removal, tension equalization, and constant speed conveying. As the core actuator of the traction mechanism, the arrangement, spatial posture, and working mode of the traction roller directly affect the film forming flatness, film feeding stability, and final product quality. It is a key component that determines the efficiency of blown film production and the product qualification rate.

[0003] Currently, the design of traditional blown film machine traction clamping roller mechanisms has obvious limitations, and these limitations are prevalent in the industry: traction clamping rollers generally adopt a horizontally parallel arrangement of axes, with both ends of the roller body strictly maintaining the same height, which can only achieve horizontal clamping and conveying of the film; even if some models adopt an eight-shaped shaping roller group design to improve the lateral flattening effect, it is only limited to the inclined arrangement within the same horizontal plane, and the roller body as a whole is still at the same horizontal reference plane, without forming any vertical tilting or misalignment. In essence, it still does not break through the limitation of horizontal force. During operation, the force on the film is always limited to a near-horizontal two-dimensional plane, which can only generate longitudinal traction force in the horizontal plane along the film walking direction and lateral expansion force in the horizontal plane. It cannot effectively guide and release the vertical internal stress remaining after the film bubble cools and closes, and it is difficult to effectively smooth out common defects such as longitudinal wrinkles and vertical wavy lines on the film surface. Furthermore, the film is subjected to force only in the near-horizontal direction and lacks effective spatial constraints. During the film feeding process, it is easily affected by factors such as minor assembly errors, tension fluctuations, and film bubble deviation, which in turn leads to production defects such as film deviation, edge wrinkling, winding ribbing, and uneven end faces.

[0004] Therefore, we propose a traction device for a blown film machine. Summary of the Invention

[0005] The purpose of this invention is to provide a traction device for a blown film machine, so as to solve the problems mentioned in the background art that the traction clamping roller mechanism of the traditional blown film machine is only limited to the near-horizontal plane, which cannot effectively relieve the vertical internal stress after the film is formed, cannot effectively smooth the longitudinal wrinkles, and lacks effective spatial limitation and mechanical balance effect, which easily leads to defects such as film deviation and wrinkling.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A traction device for a blown film machine includes a base, an A-frame, and a traction system. The traction system includes lower positioning guide rollers, a frame, multi-angle traction mechanisms, and servo motors. There are two lower positioning guide rollers, which are installed side-by-side laterally in the middle of the base. The frame is installed on top of the base, and two upper positioning guide rollers are installed in the middle of the frame. There are two sets of multi-angle traction mechanisms, which are respectively positioned on both sides of the base, and their top and bottom midpoints are rotatably connected to the frame and the base, respectively. There are two sets of servo motors, which are respectively installed at both ends of the frame and are drively connected to the top center of the corresponding two sets of multi-angle traction mechanisms.

[0007] Preferably, both sets of the multi-angle traction mechanisms include an upper fixed frame, a lower fixed frame, a main guide rail mechanism, a secondary guide rail mechanism, a roller seat assembly, a traction clamping roller, and an angle adjustment drive motor. The middle part of the lower fixed frame is rotatably mounted on a rotating seat fixed at both ends of the base. The main guide rail mechanism is fixedly mounted on the top of one end of the lower fixed frame. The secondary guide rail mechanism is fixedly mounted on the top of the other end of the lower fixed frame. There are two sets of roller seat assemblies, which are slidably assembled inside the main guide rail mechanism and the secondary guide rail mechanism, respectively. The two ends of the roller shaft of the traction clamping roller are fixed on the two sets of roller seat assemblies. The angle adjustment drive motor is mounted on the outside of the main guide rail mechanism. The two ends of the upper fixed frame are fixedly mounted to the top of the main guide rail mechanism and the secondary guide rail mechanism, respectively.

[0008] Preferably, the main guide rail mechanism and the auxiliary guide rail mechanism are arranged opposite each other at both ends of the lower fixed frame and have the same height. The opposite sides of the main guide rail mechanism and the auxiliary guide rail mechanism are both arc-shaped with equal arc radii. The outer sides of the two sets of roller seat assemblies are arc-shaped, and the roller seat assemblies, the main guide rail mechanism and the auxiliary guide rail mechanism are concentrically designed.

[0009] Preferably, both the main guide rail mechanism and the secondary guide rail mechanism include a slotted frame and an arc-shaped positioning groove. The inner side of the slotted frame is integrally formed with two parallel arc-shaped slide rails. The arc-shaped positioning groove is located between the two arc-shaped slide rails.

[0010] Preferably, the outer side of the slotted frame in the main guide rail mechanism is further provided with a mounting plate and a worm gear, and the middle part of the slotted frame in the main guide rail mechanism has an elongated slot along the length direction of the slotted frame; the mounting plate is fixedly installed on the outer side of the slotted frame by bolts, and the mounting plate is provided with mounting holes for mounting the tilt adjustment drive motor; the worm gear is arranged along the length direction of the slotted frame, and the two ends of the worm gear are rotatably assembled on the middle part of the outer side of the slotted frame through bearings, and the middle section of the worm gear is located in the elongated slot in the middle of the slotted frame; one end of the worm gear is equipped with a sprocket, and the sprocket is connected to the output end of the tilt adjustment drive motor installed on the outer side of the mounting plate through a chain.

[0011] Preferably, the roller seat assembly includes a slider, a central positioning part, an arc-shaped positioning strip and a roller clamping seat. Two arc-shaped sliding grooves adapted to the arc-shaped slide rail are integrally formed on the outer side of the slider; the central positioning part is located between the two arc-shaped sliding grooves, and the width of the central positioning part is adapted to the width of the arc-shaped positioning groove. The central positioning part is slidably assembled in the arc-shaped positioning groove; there are two arc-shaped positioning strips, and the two arc-shaped positioning strips are integrally formed on the outer sides of both ends of the central positioning part, so that an arc-shaped guide rail adapted to the inner arc of the arc-shaped positioning groove is formed between the outer sides of the two arc-shaped positioning strips and the central positioning part; the roller clamping seat is fixed to the inner side of the slider and is used for installing a traction roller.

[0012] Preferably, a worm gear tooth groove for meshing with a worm drive is provided along the circumferential direction of the outer arc of the arc-shaped guide rail arranged in the roller seat assembly installed on the main guide rail mechanism.

[0013] Preferably, a number of rows of balls arranged along the arc direction of the central positioning part are installed on both sides of the central positioning part through a steel ball positioning mesh plate, and ball grooves for the balls to roll are provided on the two side walls of the arc-shaped positioning groove.

[0014] Preferably, the traction rollers in the two multi-angle traction mechanisms are cross-designed when viewed from the front, and the two multi-angle traction mechanisms rotate in opposite directions during horizontal rotation.

[0015] Preferably, the base is integrally designed in a "hui" shape, and the herringbone frame is installed at the bottom of the base and corresponds to the direction of the lower positioning guide roller; the upper positioning guide roller and the lower positioning guide roller are both horizontally arranged and parallel to each other.

[0016] Preferably, a traction guide roller assembly and a control cabinet are further installed on the frame; the traction guide roller assembly includes a bracket and a material guiding roller, and the bracket is installed on one side of the top of the frame; there are multiple groups of material guiding rollers, and the multiple groups of material guiding rollers are installed at intervals on the top of the bracket, and the material guiding rollers are parallel to the upper positioning guide roller.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes a multi-angle traction mechanism to achieve stepless and precise adjustment of horizontal rotation and vertical inclination angle, breaking through the limitations of traditional two-dimensional near-horizontal planes. This allows for flexible adjustment of the traction roller's three-dimensional spatial posture, generating both longitudinal traction and lateral expansion forces in the horizontal plane, as well as vertical forces through roller tilting. This effectively alleviates residual vertical internal stress after the film bubble cools and closes, solving the problem of traditional traction roller mechanisms being limited to near-horizontal plane forces and unable to alleviate vertical internal stress, thus making it difficult to smooth longitudinal wrinkles and vertical wavy lines on the film surface. Simultaneously, the traction rollers in the two sets of multi-angle traction mechanisms are spatially cross-designed, forming a three-dimensional clamping constraint force with effective spatial limiting and reverse correction effects. This solves the production defects caused by traditional traction mechanisms, such as lack of spatial limiting, susceptibility to assembly errors, tension fluctuations, and film bubble misalignment, leading to issues like film deviation, edge wrinkling, winding defects, and uneven end faces. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the traction device of a blown film machine according to the present invention; Figure 2 This is a three-dimensional structural diagram of the top traction system of the traction device of a blown film machine according to the present invention; Figure 3 This is a front view structural diagram of the top traction system of the traction device of a blown film machine according to the present invention; Figure 4 This is a side view structural diagram of the top traction system of the traction device of a blown film machine according to the present invention; Figure 5 This is a schematic diagram of the multi-angle traction mechanism in this invention; Figure 6 This is a partial structural schematic diagram of the multi-angle traction mechanism in this invention; Figure 7 This is a schematic diagram of the structure of the tilt angle adjustment drive motor and the main guide rail mechanism after assembly in this invention; Figure 8 This is a schematic diagram of the structure in which the tilt adjustment drive motor achieves a transmission connection with the roller seat assembly through the main guide rail mechanism in this invention; Figure 9 This is a schematic diagram of the roller seat assembly in this invention.

[0019] In the attached diagram, the components represented by each number are as follows: 1. Base; 2. Lower positioning guide roller; 3. Multi-angle traction mechanism; 301. Lower fixed frame; 302. Main guide rail mechanism; 321. Groove frame; 322. Arc-shaped slide rail; 323. Arc-shaped positioning groove; 324. Mounting plate; 325. Worm gear; 326. Sprocket; 327. Chain; 303. Secondary guide rail mechanism; 304. Inclination adjustment drive motor; 305. Roller seat assembly; 351. Slider; 352. Clamping roller seat; 353. Central positioning part; 354. Arc-shaped chute; 355. Steel ball positioning mesh plate; 356. Ball bearing; 357. Arc-shaped positioning strip; 358. Worm gear groove; 306. Traction clamping roller; 307. Upper fixed frame; 308. Mounting hole; 4. Frame; 5. Servo motor; 6. Upper positioning guide roller; 7. Traction guide roller assembly; 701. Bracket; 702. Guide roller; 8. Control cabinet; 9. A-frame; 10. Rotary seat. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Currently, in the traction clamping roller mechanism of some traditional blown film machines, the traction clamping rollers generally adopt a horizontal parallel arrangement with the two ends of the roller body at the same height, which can only achieve horizontal clamping and conveying of the film. In order to improve the lateral flattening effect, some models have improved the original horizontal parallel arrangement of the traction clamping rollers into a horizontally designed figure-eight shaped forming roller group structure. However, even in the improved design, the roller body is limited to the inclined arrangement within the same horizontal plane, and the whole roller body is still at the same horizontal reference plane, without forming any vertical tilting or misalignment. In essence, it still does not break through the limitation of horizontal force. During the operation, the force on the film is always limited to a near-horizontal two-dimensional plane, which can only generate the longitudinal traction component in the horizontal plane along the film walking direction and the lateral expansion component in the horizontal plane. Therefore, it is impossible to effectively guide and release the vertical internal stress remaining after the film bubble cools and closes, thus making it difficult to effectively smooth out common defects such as longitudinal wrinkles and vertical wavy lines on the film surface. In addition, the traditional blown film machine traction mechanism only has near-horizontal force. During the film feeding process, it is easily affected by factors such as minor assembly errors, tension fluctuations, and film bubble deviation, which can lead to production defects such as film deviation, edge wrinkling, winding ribbing, and uneven end faces, thus affecting the final quality of the film product.

[0022] To address the limitations of traditional blown film extrusion machines' traction clamping roller mechanisms, which are confined to a near-horizontal plane in terms of force application and therefore cannot effectively alleviate vertical internal stress after film formation, smooth longitudinal wrinkles, or provide effective spatial control, leading to defects such as film deviation and wrinkling, we propose a traction device for blown film extrusion machines. The specific solution is as follows: like Figure 1 - Figure 9 As shown, the present invention provides a technical solution: a traction device for a blown film machine, including a base 1, an A-frame 9, and a traction system. The base 1 is generally designed in a "U" shape to facilitate the film belt passing through the base 1 and entering the traction system. The traction system includes a lower positioning guide roller 2, a frame 4, a multi-angle traction mechanism 3, and a servo motor 5. Specifically, there are two lower positioning guide rollers 2, which are installed side by side laterally in the middle of the base 1 and can rotate on the base 1. The A-frame 9 is installed at the bottom of the base 1 and corresponds to the direction of the lower positioning guide rollers 2. It should be noted that... The A-frame 9 adopts the A-frame 9 mechanism commonly used in blown film production equipment. The top of the A-frame 9 has a pressure roller assembly for finally extruding the film bubble into a strip. After passing through the A-frame 9 and two parallel lower positioning guide rollers 2, the film bottom of the film after the film bubble is closed is regulated, supported and initially limited by the lower positioning guide rollers 2. The film's reference position is pre-corrected to prevent the film from shifting to the left or right or sagging before entering the traction process. This provides a stable initial reference for subsequent multi-angle traction correction and ensures the consistency of the film feeding posture.

[0023] The frame 4 is installed on top of the base 1. Two upper positioning guide rollers 6 are installed in the middle of the frame 4. The upper positioning guide rollers 6 and the lower positioning guide rollers 2 are both horizontally set and parallel to each other. The frame 4 serves as the top support mounting base of the entire traction system, realizing the stable erection of the upper positioning guide rollers 6. The upper positioning guide rollers 6 and the lower positioning guide rollers 2 are arranged horizontally and parallel to each other. The lower positioning guide roller 2 is responsible for the feeding guidance of the film before it enters the traction system, while the upper positioning guide roller 6 is responsible for the accurate positioning of the film after traction correction, ensuring the stable output posture of the film after traction.

[0024] There are two sets of multi-angle traction mechanisms 3, which stand on opposite sides of the base 1. The top and bottom middle parts of the two sets of multi-angle traction mechanisms 3 are rotatably connected to the frame 4 and the base 1, respectively. The two sets of multi-angle traction mechanisms 3 rotate in opposite directions when rotating horizontally (i.e., one set rotates to the left and the other set rotates to the right), so that the two sets of multi-angle traction mechanisms 3 form a figure-eight layout in the working state. It should be noted that the horizontal rotation angle of the two sets of multi-angle traction mechanisms 3 is based on the initial angle, and the upper limit of left and right rotation is 15 degrees each. The initial angle is when the multi-angle traction mechanism 3 is parallel to the upper positioning guide roller 6 and the lower positioning guide roller 2.

[0025] Two sets of multi-angle traction mechanisms 3 are located on both sides of the top of the base 1, which can independently form a spatial attitude adjustment unit. The multi-angle traction mechanism 3 is rotatably hinged with the base 1 and the frame 4, giving the multi-angle traction mechanism 3 a horizontal degree of freedom of rotation. This breaks the structural limitations of the traditional fixed installation of traction rollers. The clamping angle and spatial attitude of the film expansion can be flexibly adjusted according to the film specifications, blow-up ratio, thickness difference, etc., to achieve three-dimensional clamping, flattening and internal stress relief of the film.

[0026] There are two sets of servo motors 5, which are respectively installed at both ends of the frame 4 and connected to the central top of the corresponding two sets of multi-angle traction mechanisms 3. They are used to drive the two sets of multi-angle traction mechanisms 3 to rotate horizontally on the top of the base 1. In the whole design, the two sets of multi-angle traction mechanisms 3 are driven independently by the two servo motors 5. This can not only realize the horizontal angle fine adjustment of a single set of multi-angle traction mechanisms 3, but also realize the horizontal angle fine adjustment by controlling the two servo motors 5 to work synchronously, or to perform continuous reciprocating low-speed rotation, so as to realize various different modes of film traction action.

[0027] In some embodiments, both sets of multi-angle traction mechanisms 3 include an upper fixed frame 307, a lower fixed frame 301, a main guide rail mechanism 302, a secondary guide rail mechanism 303, a roller seat assembly 305, a traction clamping roller 306, and an inclination adjustment drive motor 304. The middle part of the lower fixed frame 301 is rotatably mounted on a rotating seat 10 fixed at both ends of the base 1. The main guide rail mechanism 302 is fixedly mounted on the top of one end of the lower fixed frame 301. The secondary guide rail mechanism 303 is fixedly mounted on the top of the other end of the lower fixed frame 301. The two ends of the upper fixed frame 307 are respectively connected to... The main guide rail mechanism 302 and the secondary guide rail mechanism 303 are fixedly installed on the top; there are two sets of roller seat assemblies 305, which are slidably mounted on the inner sides of the main guide rail mechanism 302 and the secondary guide rail mechanism 303 respectively; the two ends of the roller shaft of the traction clamping roller 306 are fixed on the two sets of roller seat assemblies 305; the tilt angle adjustment drive motor 304 is installed on the outer side of the main guide rail mechanism 302; in addition, the main guide rail mechanism 302 and the secondary guide rail mechanism 303 are arranged opposite each other at both ends of the lower fixed frame 301 and are at the same height. At the same time, the main guide rail mechanism 302 and the secondary guide rail mechanism 303 are fixedly mounted on the top of the main guide rail mechanism 302 and the secondary guide rail mechanism 303. Both the main guide rail mechanism 302 and the auxiliary guide rail mechanism 303 have an arc design on opposite sides with equal radii. The outer sides of both sets of roller seat assemblies 305 are also arc-shaped. The roller seat assembly 305, the main guide rail mechanism 302, and the auxiliary guide rail mechanism 303 are concentrically designed. In the overall structural design of the multi-angle traction mechanism 3, the lower fixed frame 301, in conjunction with the rotating seat 10, provides stable horizontal rotational support for the entire multi-angle traction mechanism 3, laying a solid foundation for flexible adjustment of the traction posture. The symmetrical, equal-height arrangement of the main guide rail mechanism 302 and the auxiliary guide rail mechanism 303 further enhances this effect. Combined with the installation of the top fixed frame 307, a closed rigid frame support is formed, which can effectively improve the structural strength and deformation resistance of the main and auxiliary guide rail mechanisms. It can withstand the radial tensile stress during the traction process for a long time and effectively prevent the film deviation caused by guide rail deformation and offset. At the same time, the symmetrical arrangement of the two guide rails can achieve a synchronous and balanced support effect on both ends of the traction clamping roller 306, thereby avoiding the phenomenon of warping or roller body skew caused by unilateral force on the traction clamping roller 306, so as to ensure that the film is subjected to uniform force during the whole-width processing.Furthermore, the main guide rail mechanism 302 and the secondary guide rail mechanism 303, in conjunction with the roller seat assembly 305, form a concentric cooperation, allowing the two sets of roller seat assemblies 305 to slide along a standardized concentric arc trajectory. This ensures that the tilt angle adjustment at both ends of the traction clamping roller 306 is completely synchronized, and that the swing center remains unified. This achieves stepless and precise adjustment of the tilt angle of the traction clamping roller 306 in the vertical plane, adapting to the internal stress relief requirements of films of different thicknesses and materials. It completely breaks through the structural limitations of traditional fixed horizontal traction rollers. Combined with the overall horizontal rotation function of the multi-angle traction mechanism 3, it enables flexible adjustment of the three-dimensional spatial posture of the traction clamping roller 306. It can not only complete the traction and symmetrical expansion of the film in the horizontal plane, but also generate a vertical component force through roller tilting, effectively relieving the residual vertical internal stress after the film bubble cools and closes, thus smoothing out longitudinal wrinkles and vertical wavy defects at the source.

[0028] In some embodiments, both the main guide rail mechanism 302 and the secondary guide rail mechanism 303 include a slotted frame 321 and an arc-shaped positioning groove 323. The inner side of the slotted frame 321 is integrally formed with two parallel arc-shaped slide rails 322. The arc-shaped positioning groove 323 is located between the two arc-shaped slide rails 322. The slotted frame 321 adopts an integral design, which has high overall structural strength. The double parallel arc-shaped slide rails 322 form a double sliding guide constraint to limit the degree of freedom of horizontal angular displacement of the roller seat assembly 305. Only the degree of freedom of upper and lower arc-shaped swing adjustment along the arc-shaped slide rails 322 is retained, which can effectively improve the coaxiality and stability of the traction clamping roller 306 when adjusting the tilt angle.

[0029] In some embodiments, in order to enable the electric adjustment of the vertical tilt angle of the traction clamping roller 306, a mounting plate 324 and a worm gear 325 are provided on the outer side of the slotted frame 321 in the main guide rail mechanism 302. Simultaneously, a long slot is formed in the middle of the slotted frame 321 along its length to provide clearance for the transmission engagement between the worm gear 325 and the roller seat assembly 305 mounted on the main guide rail mechanism 302. The transmission structure layout is compact and reasonable. Furthermore, the mounting plate 324 is fixedly mounted on the outer side of the slotted frame 321 by bolts, and the mounting plate 324 is provided with mounting holes 308 for mounting the tilt angle adjustment drive motor 304. The mounting plate 324 is detachably assembled and fixed, which facilitates the overall assembly and disassembly and is also beneficial for the maintenance of later parts. The worm gear 325 is set along the length of the slot frame 321. The two ends of the worm gear 325 are rotatably mounted on the middle of the outer side of the slot frame 321 through bearings, and the middle section of the worm gear 325 is located in the long slot hole in the middle of the slot frame 321. At the same time, a sprocket 326 is also installed at one end of the worm gear 325. The sprocket 326 is connected to the output end of the tilt adjustment drive motor 304 installed on the outer side of the mounting plate 324 through the chain 327. The tilt adjustment drive motor 304 realizes power transmission through the cooperation of the chain 327 and the sprocket 326, thereby driving the worm gear 325 to rotate forward and backward.

[0030] In some embodiments, in order to cooperate with the main guide rail mechanism 302 and the tilt angle adjustment drive motor 304 to realize the tilt angle adjustment of the traction clamping roller 306, the roller seat assembly 305 includes a slider 351, a central positioning part 353, an arc-shaped positioning strip 357 and a clamping roller seat 352. The slider 351 has two arc-shaped grooves 354 integrally formed on its outer side that are adapted to the arc-shaped slide rail 322. The arc-shaped grooves 354 and the arc-shaped slide rail 322 fit precisely to achieve sliding assembly, thereby restricting the lateral movement of the slider 351. In addition, the large contact area between the arc-shaped grooves 354 and the arc-shaped slide rail 322 can disperse the force between the arc-shaped grooves 354 and the arc-shaped slide rail 322, thereby enabling the slider 351 to slide smoothly and effectively avoiding the feeling of jerking.

[0031] In some embodiments, the central positioning part 353 is located between two arc-shaped slide grooves 354, and the width of the central positioning part 353 is adapted to the width of the arc-shaped positioning groove 323. The central positioning part 353 is slidably assembled in the arc-shaped positioning groove 323. The central positioning part 353 and the arc-shaped positioning groove 323 are precisely fitted with a clearance to form a central guiding positioning. Together with the two arc-shaped slide grooves 354 on both sides, they form a three-point limiting, which can effectively prevent the slider 351 from swaying and tilting, thereby ensuring that the roller seat assembly 305 always moves along the preset arc trajectory, so that the tilt angle adjustment accuracy is controllable.

[0032] In some embodiments, there are two arc-shaped positioning strips 357, which are integrally formed on the outer sides of both ends of the central positioning part 353. This allows the two arc-shaped positioning strips 357 and the outer side of the central positioning part 353 to form an arc guide rail that matches the curvature of the inner side of the arc-shaped positioning groove 323. The arc-shaped positioning strips 357 and the central positioning part 353 are combined to form an integral arc guide rail, which fits precisely with the inner side of the arc-shaped positioning groove 323. This not only increases the length of the contact guide surface, disperses local stress, and avoids wear caused by single-point force, but also improves the smoothness of sliding and structural stability, as well as increases the range of vertical movement of the roller seat assembly 305 within the main guide rail mechanism 302.

[0033] In some embodiments, the clamping roller seat 352 is fixed to the inner side of the slider 351 for mounting the traction clamping roller 306. The clamping roller seat 352 and the slider 351 are fixedly connected by bolts, which facilitates the installation and disassembly of the traction clamping roller 306. It should be noted that the traction clamping roller 306 mainly consists of a roller shaft and a roller body sleeved on the outer circumference of the roller shaft. The roller body and the roller shaft are assembled by bearings, allowing the roller body to rotate outside the roller shaft. The two ends of the roller shaft are rigidly connected to the clamping roller seat 352 to ensure the coaxiality of the traction clamping roller 306 after assembly with the two sets of roller seat assemblies 305, so that the traction clamping roller 306 can rotate more flexibly when adjusting the tilt angle.

[0034] In some embodiments, the outer side of the arc guide rail of the roller seat assembly 305 mounted on the main guide rail mechanism 302 is provided with a worm gear groove 358 along the circumferential direction of the arc guide rail for meshing with the worm gear 325. The worm gear groove 358 and the worm gear 325 form an arc meshing transmission of worm gear and worm, which can convert the rotational power of the tilt angle adjustment drive motor 304 into the arc swing motion of the roller seat assembly 305, realize the stepless adjustment of the tilt angle of the traction clamping roller 306, and after the tilt angle adjustment drive motor 304 stops, it can use the self-locking characteristic of the worm gear 325 transmission to resist production vibration, so that the traction clamping roller 306 does not deviate in angle, thereby continuously ensuring the film correction effect.

[0035] In some embodiments, several rows of balls 356 arranged along the arc direction of the central positioning part 353 are installed on both sides of the central positioning part 353 via steel ball positioning mesh plates 355. The side walls of the arc-shaped positioning groove 323 are provided with ball grooves for the balls 356 to roll, and solid lubricating oil is filled in the gaps in the ball grooves. By arranging multiple rows of balls 356 along the arc direction of the central positioning part 353, the traditional sliding friction is transformed into rolling friction, which can effectively reduce the frictional resistance between the roller seat assembly 305 and the arc-shaped positioning groove 323, thereby reducing the driving load when the roller seat assembly 305 moves, making the roller seat assembly 305 move more easily and quietly. At the same time, by using the multi-point support and limiting of the balls 356, the sliding gap can be further eliminated, thereby improving the sensitivity and accuracy of the attitude adjustment of the traction clamping roller 306.

[0036] In some embodiments, the traction clamping rollers 306 in the two sets of multi-angle traction mechanisms 3 are designed to cross each other when viewed from the front. The traction clamping rollers 306 in the two sets of multi-angle traction mechanisms 3 form a three-dimensional cross posture through the cross-inclined design, which forms a three-dimensional clamping constraint force on the film. In the horizontal direction, the cross-set clamping rollers generate opposing lateral expansion tension on the film, which can quickly flatten the film width and eliminate lateral wrinkles. In the vertical direction, the inclined clamping rollers generate a uniform vertical component force on the film, which is used to relieve the internal stress of the film. Together with the horizontal expansion force and the longitudinal tension force, they form a three-dimensional spatial mechanical balance system, realizing all-round positioning and mechanical balance of the film.

[0037] In some embodiments, in terms of preventing film deviation, when the film tends to deviate due to factors such as assembly error, tension fluctuation, and film bubble offset, the cross-arranged traction clamping rollers 306 will generate greater clamping friction and reverse correction force on the film on the deviated side. By utilizing the reverse constraint effect of three-dimensional mechanical balance, the deviated film is pulled back to the preset film path. At the same time, the symmetrical cross structure can ensure that the force on both sides of the film is always balanced, avoiding the aggravation of deviation caused by excessive force on one side, thereby solving problems such as film deviation, edge wrinkling, winding creases, and uneven end faces.

[0038] In some embodiments, the frame 4 is also equipped with a traction guide roller assembly 7 and a control cabinet 8, wherein the control cabinet 8 is used to coordinate and control the movement of each motor in the entire traction device; the traction guide roller assembly 7 includes a bracket 701 and a guide roller 702, the bracket 701 is installed on one side of the top of the frame 4; there are multiple sets of guide rollers 702, which are spaced apart on the top of the bracket 701, and the guide rollers 702 are arranged in parallel with the upper positioning guide roller 6; the multiple sets of parallel guide rollers 702 form a multi-level orderly guiding and conveying structure, which gradually releases the film tension, smoothly transitions the film direction, thereby avoiding stretching wrinkles and stress concentration when the film turns sharply, and improving the smoothness of film feeding and the flatness of the finished film.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A traction device for a blown film machine, comprising a base, an A-frame, and a traction system, characterized in that, The traction system includes: There are two lower positioning guide rollers, which are installed side by side in the middle of the base. The frame is installed on top of the base, and two upper positioning guide rollers are installed in the middle of the frame. The multi-angle traction mechanism consists of two sets, which are respectively positioned on both sides of the base. The top and bottom middle parts of the two sets of multi-angle traction mechanisms are rotatably connected to the frame and the base, respectively. There are two sets of servo motors, which are respectively installed at both ends of the frame and connected to the central drive at the top of the corresponding two sets of multi-angle traction mechanisms.

2. The traction device for a blown film machine according to claim 1, characterized in that, Both sets of multi-angle traction mechanisms include: The lower fixed frame is rotatably mounted on the rotating seats fixed at both ends of the base. The main guide rail mechanism is fixedly installed on the top of one end of the lower fixed frame; A secondary guide rail mechanism is fixedly installed on the top of the other end of the lower fixed frame; The roller seat assembly consists of two sets, which are slidably mounted inside the main guide rail mechanism and the secondary guide rail mechanism, respectively. The traction clamping roller has its two ends fixed on two sets of roller seat assemblies; The tilt angle adjustment drive motor is mounted on the outside of the main guide rail mechanism; The upper fixed frame is fixedly installed at both ends to the top of the main guide rail mechanism and the secondary guide rail mechanism, respectively.

3. The traction device for a blown film machine according to claim 2, characterized in that, The main guide rail mechanism and the auxiliary guide rail mechanism are arranged opposite each other at both ends of the lower fixed frame and have the same height. The opposite sides of the main guide rail mechanism and the auxiliary guide rail mechanism are both arc-shaped with equal radii. The outer sides of the two sets of roller seat assemblies are arc-shaped, and the roller seat assemblies, the main guide rail mechanism and the auxiliary guide rail mechanism are concentrically designed.

4. A traction device for a blown film machine according to claim 2 or 3, characterized in that, Both the main guide rail mechanism and the secondary guide rail mechanism include: The slotted frame has two parallel arc-shaped slide rails integrally formed on its inner side; The arc-shaped positioning groove is located between two arc-shaped slide rails.

5. The traction device for a blown film machine according to claim 4, characterized in that, The main guide rail mechanism is equipped with a mounting plate and a worm gear on the outside of the slotted frame, and a long slot is opened in the middle of the slotted frame along the length of the slotted frame. The mounting plate is fixedly installed on the outside of the slotted frame with bolts, and the mounting plate is provided with mounting holes for mounting the tilt adjustment drive motor; The worm is set along the length of the slotted frame. Both ends of the worm are rotatably mounted on the middle of the outer side of the slotted frame through bearings, and the middle section of the worm is located in the long slot in the middle of the slotted frame. A sprocket is installed at one end of the worm, and the sprocket is connected to the output end of the tilt adjustment drive motor installed on the outer side of the mounting plate through a chain.

6. The traction device for a blown film machine according to claim 2, characterized in that, The roller assembly includes: The slider has two integrally formed arc-shaped grooves on its outer side that are adapted to the arc-shaped slide rail. The central positioning part is located between two arc-shaped grooves, and the width of the central positioning part is adapted to the width of the arc-shaped positioning groove. The central positioning part is slidably assembled in the arc-shaped positioning groove. The arc-shaped positioning strip consists of two strips, which are integrally formed on the outer sides of both ends of the central positioning part, so that the two arc-shaped positioning strips and the outer side of the central positioning part form an arc guide rail that matches the curvature of the inner side of the arc-shaped positioning groove. The clamping roller seat is fixed inside the slider and is used to install the traction clamping roller.

7. The traction device for a blown film machine according to claim 6, characterized in that, On the roller seat assembly installed on the main guide rail mechanism, a worm gear groove for meshing with the worm drive is provided along the circumferential direction of the arc of the outer side of the arc guide rail.

8. The traction device for a blown film machine according to claim 6, characterized in that, On both sides of the central positioning part, a number of rows of balls are installed along the arc direction of the central positioning part through the steel ball positioning mesh plate, and ball grooves for the balls to roll are provided on both side walls of the arc positioning groove.

9. The traction device for a blown film machine according to claim 2, characterized in that, The traction pinch rollers in the two groups of multi-angle traction mechanisms are cross-designed when viewed from the front, and the two groups of multi-angle traction mechanisms rotate in opposite directions during horizontal rotation.

10. The traction device for a blown film machine according to claim 1, characterized in that, The base is integrally designed in a "return" shape, and the herringbone frame is installed at the bottom of the base and corresponds to the direction of the lower positioning guide roller; The upper positioning guide roller and the lower positioning guide roller are both horizontally arranged and parallel to each other; A traction guide roller assembly and a control cabinet are also installed on the frame; The traction guide roller assembly includes: A bracket installed on one side of the top of the frame; Feeding guide rollers, there are multiple groups of feeding guide rollers, which are installed at intervals on the top of the bracket, and the feeding guide rollers are parallel to the upper positioning guide roller.

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