A film feeding mechanism with self-adjusting tension size and uniformity

Abstract

The application provides a film feeding mechanism with self-adjusting tension size and uniformity, comprising a film reel, a first tension adjusting module, a second tension adjusting module, a third tension adjusting module and a pre-deformation module, the first tension adjusting module and the second tension adjusting module jointly control the overall tension of the film, the pre-deformation module pre-adjusts the shape of the film to adapt to the surface of the bale, simultaneously monitors and transmits the abnormal tension generated by the deflection in the vertical plane when the film is pulled out, and feeds back to the third tension adjusting module to adjust the cross-section tension. The application has the beneficial effects that: the first tension adjusting module uses a one-way self-locking mechanism and a spring to cooperate, stabilizes the film tension, and realizes quick loading and unloading of the film reel; the pre-deformation module pre-deforms the film into a shape suitable for the bale, reduces the film breakage rate, and the two-section structure realizes quick transmission of abnormal tension; and the third tension adjusting module realizes self-correction of the film in the vertical plane.

Description

Technical Field

[0001] This invention relates to a film feeding mechanism that self-adjusts the tension magnitude and uniformity. Background Technology

[0002] Wrapping storage, a common method for storing forage, is popular among small and medium-sized farmers due to its advantages such as high controllability of production conditions, ease of transportation, and low loss rate during handling. Wrapping storage requires using a wrapping machine to evenly stretch the film and tightly adhere it to the surface of the forage bales to extend the storage time and withstand compression and collisions during transportation. However, the current wrapping process has the following problems: First, films from different manufacturers vary in thickness and quality standards, making it difficult to control the film tension. Second, in actual wrapping, forage bales often form frustum-shaped cones rather than ideal cylinders, making it difficult to maintain consistent tension on both sides of the film and ensuring film uniformity. Third, due to the complexity of the forage bale surface shape, the film is prone to irregular deformation during wrapping, which may cause the film to skew in the vertical plane, resulting in abnormal tension in the lateral and longitudinal directions, affecting the film's wrapping performance and ultimately impacting the overall quality of the stored bales. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a film feeding mechanism with self-adjusting tension magnitude and uniformity.

[0004] The main technical solution of the self-adjusting film feeding mechanism for tension magnitude and uniformity provided by the present invention is as follows: It includes a film roll for holding the film roll to be used; a first tension adjustment module, including a first gear, a second gear, a third gear, a movable bracket, a movable shaft, a first flat belt support shaft, a second flat belt support shaft, a flat belt, a ratchet, a pawl, a spring, and a boss, for adjusting the overall tension of the film; a second tension adjustment module, including a first pulley, a second pulley, a belt, and a guide rod, which connects to the first tension adjustment module to jointly ensure the uniformity of the film; a third tension adjustment module, including a correction rod and a cross slider, for transmitting abnormal tension generated when the film is skewed in the vertical plane, so as to adjust the tension of the film section; and a pre-deformation module, including a shaping ellipsoid, a shaping bracket, and a transmission handle, for pre-adjusting the shape of the film and simultaneously monitoring and transmitting abnormal tension generated when the film is skewed in the vertical plane.

[0005] The technical solution adopted in this invention also includes the following components and their auxiliary solutions: The film roll is vertically mounted between the upper and lower plates of the frame through its shaft hole and can rotate freely.

[0006] The first tension adjustment module is located between the upper and lower plates of the frame and is in close contact with the film roll; the first gear is located at the end of the second flat belt support shaft and above the upper plate of the frame; the second gear is located above the upper plate of the frame between the end of the second flat belt support shaft and the end of the film roll, and can rotate freely; the second gear has a cylindrical boss; the third gear is located at the end of the film roll and above the upper plate of the frame; the first gear meshes with the second gear, and the third gear meshes with the cylindrical boss on the second gear; The movable support can be freely opened and closed along the movable axis; the first flat belt support shaft and the second flat belt support shaft are located on both sides of the movable support and can rotate freely along the axial direction; the second flat belt support shaft is connected to the upper plate and the lower plate of the frame through a bearing seat; the flat belt is sleeved on the first flat belt support shaft and the second flat belt support shaft and can roll freely; the ratchet and the pawl are both above the upper plate of the frame; the ratchet is located at the end of the film roll and is coaxial with the third gear; the ratchet has the boss; the spring connects the boss and the movable axis. When the film feeding mechanism is working, the film roll begins to rotate due to the tension of the film. The ratchet and the third gear rotate with the film roll. The spring tightens with the unidirectional rotation of the ratchet, causing the movable bracket to open and move closer to the film roll. The first gear rotates with the third gear through the transmission of the second gear. The second flat belt support shaft rotates under the action of the first gear. The flat belt rotates under the combined action of the spring and the first gear and applies pressure to the film roll. The spring and the movable bracket move radially towards the axis as the film roll is used, which can ensure that the flat belt applies stable pressure to the film. When the ratchet rotates unidirectionally until the boss exceeds the position of the pawl, the direction of the spring tension and the self-locking direction of the ratchet change from the same to opposite. At this time, the first tension adjustment module will return to the initial relaxed state, and operations such as changing the film roll can be performed.

[0007] The second tension adjustment module is located above the upper plate of the frame; the first pulley is located at the end of the second flat belt support shaft and is coaxial with the first gear; the second pulley is located at the end of the guide rod; both the first and second pulleys have a multi-variable diameter structure; the belt is tensioned between the first and second pulleys; the guide rod is fixed between the upper and lower plates of the frame via a bearing seat and is located at the film pulling position. When the film feeding mechanism is working, the second tension adjustment module and the first tension adjustment module work at different linear speeds, and the film will be subjected to uniform tension between the flat belt and the guide rod, ensuring that the uniformity of the film is adjusted; at the same time, the diameters of the first and second pulleys can be selected according to the different film materials to achieve uniformity adjustment for different film materials.

[0008] The third tension adjustment module is located between the first tension adjustment module and the pre-deformation module; one end of the correction rod is connected to the movable shaft via the cross slider, and the other end of the correction rod passes through the hole of the transmission handle and is connected to the frame column via a ball hinge; the correction rod can move axially along the movable shaft. When the correction rod is subjected to abnormal tension transmitted from the transmission handle, the correction rod will apply pressure to the movable shaft and move in the direction of the abnormal tension, automatically adjusting the pressure distribution of the first tension adjustment module on the film cross-section, so that the friction force received on the elongated side of the film is less than the friction force on the shortened side, until the film is not skewed on the vertical plane, thereby achieving self-correction on the vertical plane of the film.

[0009] The pre-deformation module is located in the direction of film outgoing; a very narrow gap is left between the shaping ellipsoid and the shaping support; the transfer handle is connected to the shaping support via a ball joint, and the other end of the transfer handle has a hole. When the film feeding mechanism is working, the film is pulled out from the guide rod, passes through the gap between the shaping ellipsoid and the shaping support, and at this time the film is subjected to a tensile force that decreases from the centerline to both ends, and is pre-shaped into a curved surface adapted to the bale; when the film deviates in the vertical plane, the transfer handle will transmit the abnormal tension generated by the deviance to the third tension adjustment module for adjustment.

[0010] The beneficial effects of this invention are: 1. The technical solution of this invention utilizes the proportional relationship between the number of ratchet teeth and the number of turns of the film roll, in conjunction with a spring and a movable support, to achieve stable film tension. The diameter of the film roll decreases continuously during use. This device adjusts the spring tension in real time by changing the position of the spring attachment point on the ratchet, causing the spring and movable support to move radially towards the axis as the film roll is used. Simultaneously, the spring tension remains stable due to its unchanged length, ensuring that the frictional resistance between the flat belt and the film remains constant despite changes in film diameter. This mechanism overcomes the problem of traditional methods using butterfly or drum-type friction to provide constant torque resistance, where film tension increases with different film diameters.

[0011] 2. The pre-deformation module in the technical solution of the present invention applies a tension force that decreases from the midpoint of the cross-section to both ends of the film, so that the film is deformed in advance into a curved surface that adapts to the bundled product, thereby reducing the breakage rate of the film during the packaging process and improving the utilization rate of raw materials. Furthermore, by replacing the shaping ellipsoids of different shapes, the pre-deformation requirements under different working conditions can be met.

[0012] 3. In the technical solution of this invention, the two-section structure of the pre-deformation module senses the abnormal tension generated when the film is tilted in the vertical plane and feeds it back to the third tension adjustment module, so that the correction rod moves on the movable shaft, adjusts the pressure center of the first tension adjustment module on the film roll, and automatically adjusts the direction of the film to achieve self-correction of the film; at the same time, the pre-deformation module uses rigid elements to directly feed back to the third tension adjustment module, which makes the response time very short and avoids the problems of long response time, aging, and fatigue of electronic components.

[0013] 4. The technical solution of this invention utilizes the one-way self-locking characteristic of a ratchet, combined with the action of a spring, to achieve an automatic release mechanism by setting the proportional relationship between the number of ratchet teeth and the number of turns of the film roll. When the film is used up, the boss on the ratchet will just exceed the pawl position (i.e., the self-locking critical position), causing the direction of the spring tension force and the self-locking direction of the ratchet mechanism to change from opposite to the same. At this time, the first tension adjustment module automatically releases and returns to the initial relaxed state. Alternatively, the ratchet can be manually rotated to pass the self-locking critical position after the film is used up. The automatic release mechanism simplifies the loading and unloading process of the film roll and improves the efficiency of film roll replacement. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the device of the present invention.

[0015] Figure 2 This is a top view of the device of the present invention.

[0016] Figure 3 This is an axial sectional view of the device of the present invention.

[0017] Figure 4 This is a partial enlarged view (gear) of the device of the present invention.

[0018] Figure 5 This is a schematic diagram of the pre-deformation module of the device of the present invention. Detailed Implementation

[0019] See Figure 1 According to an embodiment of the film feeding mechanism with self-adjusting tension magnitude and uniformity provided by the present invention, it includes a film roll 1, a first tension adjustment module 2, a second tension adjustment module 3, a third tension adjustment module 4, and a pre-deformation module 5.

[0020] The following is combined Figure 2 , Figure 3 , Figure 4 and Figure 5 The specific structure of the device of the present invention will be further described below.

[0021] The film roll 1 is vertically mounted between the upper and lower plates of the frame through its shaft hole and can rotate freely; the first tension adjustment module 2 includes a first gear 6, a second gear 7, a third gear 8, a movable bracket 9, a movable shaft 10, a first flat belt support shaft 111, a second flat belt support shaft 112, a flat belt 12, a ratchet 13, a pawl 14, a spring 15, and a boss 25; the second tension adjustment module 3 includes a first pulley 16, a second pulley 17, a belt 18, and a guide rod 21; the third tension adjustment module 4 includes a correction rod 19 and a cross slider 20; the pre-deformation module 5 includes a shaping ellipsoid 22, a shaping bracket 23, and a transfer handle 24.

[0022] The film roll 1 is located between the upper plate and the lower plate of the frame and can rotate freely in the vertical direction. The lower end of the film roll 1 is provided with a truncated cone for placing the film roll to be used. When the film roll is placed on the film roll 1, the tapered diameter structure of the truncated cone stabilizes film rolls of different inner diameters on the film roll 1. When the film is pulled out, the film roll rotates together with the film roll 1.

[0023] The first tension adjustment module 2 is located between the upper plate and the lower plate of the frame, and is close to the radial side of the film roll 1. The first gear 6 is located at the end of the second flat belt support shaft 112; the second gear 7 is located on the upper plate of the frame at the end between the end of the second flat belt support shaft 112 and the film roll 1; the second gear 7 has a cylindrical boss; the third gear 8 is located at the end of the film roll 1; the first gear 6 meshes with the second gear 7, and the third gear 8 meshes with the cylindrical boss on the second gear 7. The movable bracket 9 can be freely opened and closed along the movable shaft 10; the first flat belt support shaft 111 and the second flat belt support shaft 112 are located on both sides of the movable bracket 9 and can rotate freely along the axial direction; the second flat belt support shaft 112 is connected to the upper plate and the lower plate of the frame through a bearing seat; the flat belt 12 is fitted onto the first flat belt support shaft 111 and the second flat belt support shaft 112 and can roll freely; the ratchet 13 is located at the end of the film roll 1 and is coaxial with the third gear 8; the boss 25 is on the ratchet 13; the spring 15 is fitted between the boss 25 and the movable shaft 10. When the film feeding mechanism is working, the film roll 1 begins to rotate under the tension of the film, and the ratchet 13 and the third gear 8 rotate together; the position of the boss 25 moves with the unidirectional rotation of the ratchet 13; the spring 15 tightens as the boss 25 moves, causing the movable bracket 9 to open and move closer to the film roll 1; during the rotation of the ratchet 13, the distance between the boss 25 and the movable shaft 10 remains constant, the length of the spring 15 remains unchanged and provides stable tension; the first gear 6 rotates with the third gear 8 through the transmission of the second gear 7; the second flat belt support shaft 112 rotates under the action of the first gear 6; the flat belt 12 rotates with the film under the combined action of the spring 15 and the first gear 6 and applies radial pressure to the film roll. When the diameter of the film roll decreases due to film consumption, the length of the spring 15 remains constant and provides a stable tension force, meaning the friction force of the flat belt 12 on the film is constant, ensuring the uniformity of film stretching. The ratchet mechanism composed of the ratchet 13 and the pawl 14 has a unidirectional self-locking property. During film feeding, the spring 15 needs to provide a force in the same direction as the ratchet 13 for self-locking. When the boss 25 exceeds the position of the pawl 14, the tension applied by the spring 15 changes from the same direction to the opposite direction of the self-locking of the ratchet 13. By setting the ratio of the number of teeth required for the boss 25 to reach the pawl 14 to the number of rotations of the film roll during this period, the boss 25 can just exceed the position of the pawl 14 when the film is used up. At this time, the first tension adjustment module 2 will return to the initial relaxed state, making the operation more convenient and safer when changing the film roll.

[0024] The second tension adjustment module 3 is located above the upper plate of the frame. The first pulley 16 is located at the end of the second flat belt support shaft 112 and is coaxial with the first gear 6; the second pulley 17 is located at the end of the guide rod 21; the first pulley 16 and the second pulley 17 are connected by the belt 18; the guide rod 21 is fixed between the upper plate and the lower plate of the frame by a bearing seat and is located at the position where the film is pulled out; the first pulley 16 and the second pulley 17 each have two layers of pulleys with different diameters. When the film feeding mechanism is working, the second flat belt support shaft 112 rotates with the flat belt 12, driving the first pulley 16 to rotate, which in turn drives the guide rod 21 through the belt 18 and the second pulley 17. The linear velocity ratio between the guide rod 21 and the flat belt 12 is selectable and constant. The two ends of the film are subjected to a stable tensile force between the flat belt 12 and the guide rod 21, and the uniformity of the film is adjusted. To meet different stretching requirements, the ratio of the diameters of the first pulley 16 and the second pulley 17 can be changed to adjust the linear velocity ratio between the flat belt 12 and the guide rod 21, thereby changing the tensile force received at both ends of the film and achieving uniform stretching of different films to meet the wrapping requirements of different bales.

[0025] The third tension adjustment module 4 is located between the first tension adjustment module 2 and the pre-deformation module 5. One end of the correction rod 19 is connected to the movable shaft 10 through the cross slider 20; the other end of the correction rod 19 is connected to a hole passing through the transmission handle 24; the end of the correction rod 19 is connected to the frame column through a ball hinge; the correction rod 19 can slide up and down on the movable shaft 10 and apply pressure. When the film feeding mechanism is working normally, the correction rod 19 is located at the midpoint of the movable shaft 10. When the film is tilted due to the complex surface of the bale, resulting in abnormal tension on the vertical plane, the correction rod 19 will be subjected to the abnormal tension transmitted by the transmission handle 24. The correction rod 19 will apply pressure on the movable shaft 10 and move in the direction of the abnormal tension, adjusting the pressure distribution of the first tension adjustment module 2 on the film cross-section, so that the friction force received on the elongated side of the film is less than the friction force on the shortened side. The adjusted film resists the abnormal tension on the vertical plane and continuously compensates for the tilt until the film is no longer tilted on the vertical plane. At this time, the abnormal tension disappears, the correction rod 19 returns to the initial midpoint of the movable shaft 10, the compensation ends, and the self-correction of the film on the vertical plane is realized.

[0026] The pre-deformation module 5 is located on one side of the film roll 1, in the direction of film outwards. A narrow gap is left between the shaping ellipsoid 22 and the shaping bracket 23; the shaping ellipsoid 22 can rotate on the shaping bracket 23; the shaping bracket 23 is only connected to the transmission handle 24 through a spherical joint, and the shaping ellipsoid 22 can rotate freely around the spherical joint in its plane along with the shaping bracket 23; the correction rod 19 passes through the hole at the end of the transmission handle 24. When the film feeding mechanism is working, the film is pulled out from the guide rod 21, passes through the narrow gap between the shaping ellipsoid 22 and the shaping bracket 23, and wraps the bale of straw. The shaping ellipsoid 22 rotates as the film is pulled out. The film is subjected to the frictional force of the shaping ellipsoid 22 and is subjected to a tensile force that decreases from the center line to both ends, and is pre-shaped into a curved surface that adapts to the bale-shaped product. When the film deviates in the cross-sectional direction, the film transmits abnormal tension to the shaping ellipsoid 22 and the shaping bracket 23, and then to the transmission handle 24 through the ball joint. The transmission handle 24 rotates in the direction of abnormal tension, converting the abnormal tension generated by the film deviance into an up-and-down pulling force on the correction rod 19, causing the correction rod 19 to deviate from the midpoint of the movable axis 10 and begin self-correction.

[0027] This invention provides a film feeding mechanism with self-adjusting tension magnitude and uniformity. Its core involves an innovative tension adjustment mechanism that achieves real-time stable adjustment of film tension through the cooperation of a ratchet and a spring. Furthermore, a pre-deformation module is introduced, applying a tension that decays from the film's centerline towards both ends, allowing the film to adapt to the shape of bundled products before packaging, effectively reducing breakage rates and improving material utilization efficiency. This technical solution also features a self-correcting function, automatically detecting and adjusting the film orientation to solve the problem of skewing caused by complex product surfaces. Simultaneously, utilizing the unidirectional self-locking characteristic of the ratchet, an automatic release mechanism is designed, simplifying the film roll replacement process and significantly improving work efficiency. Through these technical solutions, this invention solves the technical problems of traditional film feeding mechanisms in terms of tension stability, film breakage rate, orientation adjustment, and replacement efficiency.

Claims

1. A film feeding mechanism with self-adjusting tension magnitude and uniformity, characterized in that, include: Thin film rolls; The first tension adjustment module is located between the upper plate and the lower plate of the frame and is in close contact with the film roll. It includes a gear set, a flat belt support, a flat belt, a one-way intermittent motion mechanism, and a spring, and is used to adjust the overall tension when the film is pulled out. The second tension adjustment module, located directly above the upper plate of the frame, includes a first pulley, a second pulley, a belt, and a guide rod. During operation, it connects with the first tension adjustment module to jointly ensure film uniformity. The third tension adjustment module, located between the pre-deformation module and the first tension adjustment module, includes a correction rod and a cross slider. It is used to transmit abnormal tension generated by the film's vertical plane deviation, thereby adjusting the film's cross-sectional tension. The pre-deformation module, located at the film's exit point, includes a shaping ellipsoid, a shaping bracket, and a transfer handle. It is used to pre-adjust the film shape to adapt to the complex surface of the bale, while simultaneously monitoring and transmitting abnormal tension generated when the film's vertical plane is deviated. The film roll is vertically mounted between the upper and lower plates of the frame through its shaft hole and can rotate freely. The flat belt support includes a movable bracket, a movable shaft, a first flat belt support shaft, and a second flat belt support shaft. The flat belt support can open and close around the movable shaft. The flat belt can rotate on the flat belt support. The second flat belt support shaft is connected to the upper and lower plates of the frame through a bearing seat.

2. The film feeding mechanism with self-adjusting tension magnitude and uniformity according to claim 1, characterized in that: The gear set includes a first gear, a second gear, and a third gear; the first gear is located at the end of the second flat belt support shaft; the third gear is located at the end of the film roll. The second gear is located above the upper plate of the frame between the first gear and the third gear; the second gear is provided with a cylindrical boss, and the third gear meshes with the cylindrical boss on the second gear; the first gear meshes with the second gear.

3. The film feeding mechanism with self-adjusting tension magnitude and uniformity according to claim 2, characterized in that: The unidirectional intermittent motion mechanism includes a ratchet, a pawl, and a boss; the ratchet is located at the end of the film roll, above the third gear; the boss is provided on the ratchet; the pawl is located above the upper plate of the frame next to the ratchet; the movable shaft is connected to the boss through the spring; the cooperation of the ratchet, the pawl, the boss, and the spring realizes the automatic release of the flat belt support.

4. The film feeding mechanism with self-adjusting tension magnitude and uniformity according to claim 1, characterized in that: The guide rod is located at the position where the film is pulled out and is connected to the upper plate and lower plate of the frame through a bearing seat; the first pulley is located at the end of the second flat belt support shaft, the second pulley is located at the end of the guide rod, and the belt is tensioned on the first pulley and the second pulley; the first pulley and the second pulley are both multi-layer structures with different wheel diameters; the second tension adjustment module works together with the first tension adjustment module to provide a stable tensile force to the film by utilizing the difference in linear velocity between the flat belt and the guide rod.

5. The film feeding mechanism with self-adjusting tension magnitude and uniformity according to claim 1, characterized in that: One end of the correction rod is connected to the movable shaft via the cross slider, and the other end passes through the hole on the transmission handle. The other end is connected to the vertical column of the frame between the upper plate and the lower plate of the frame via a ball hinge. After being subjected to abnormal tension by the pre-deformation module, the correction rod moves on the movable shaft and applies pressure, which can change the distribution of the tension in the membrane cross section.

6. The film feeding mechanism with self-adjusting tension magnitude and uniformity according to claim 1, characterized in that: The shaping ellipsoid and the shaping support have a narrow gap. The film is led out from the guide rod, passes through the gap between the shaping ellipsoid and the shaping support, and is subjected to a tensile force that decreases from the center line to both ends, thus being pre-shaped into a curved surface adapted to the bale. The transmission handle is connected to the shaping support through a ball joint, and the correction rod passes through the hole at the end of the transmission handle. When the film is tilted on the vertical plane due to the frustum-shaped bale, the transmission handle will transmit the abnormal tension generated by the film tilt to the third tension adjustment module for self-correction.

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