A film unwinding device and bag making machine
By designing a tensioning mechanism and a threaded drive assembly for the unwinding device, the problem of poor adaptability of the unwinding device was solved, enabling rapid adaptation to different roll cores and production stability, reducing equipment costs, and improving the automation level of the bag making machine.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SICHUAN SHENGZUN NEW MATERIALS CO LTD
- Filing Date
- 2025-07-31
- Publication Date
- 2026-05-29
AI Technical Summary
The existing unwinding device has poor structural adaptability and cannot adapt to different core sizes. When running at high speed, the concentricity is insufficient, which leads to film swaying and tension fluctuation, affecting the automation level and production efficiency of the bag making machine.
An unwinding device comprising a tensioning mechanism, a sliding sleeve, a drive assembly, and an opening and closing assembly was designed. By radially adjusting the sliding sleeve and the tensioning plate, rapid clamping and release of winding cores with different inner diameters can be achieved. A threaded drive assembly and a double-plane bearing are used to reduce friction and ensure synchronization and stability.
It enables rapid adaptation to different cores, reduces equipment costs, avoids the need for multi-specification air expansion shafts, improves the adaptability and production stability of the unwinding device, and reduces tension fluctuations and shaking.
Smart Images
Figure CN224298432U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of manufacturing machinery, and more specifically, it relates to an unwinding device and a bag making machine. Background Technology
[0002] Valve bag making machines are key equipment for producing packaging bags made of plastic, paper, etc. They mainly include an unwinding device, a conveying system, a cutting mechanism, a folding device, a heat-sealing mechanism, and a control system. The unwinding device carries the rolled raw material and controls the unwinding tension; the conveying system guides the material into the processing area; the cutting mechanism cuts the material to set dimensions; the folding mechanism folds the material; the heat-sealing mechanism seals the bag through heating and pressurization; and the control system coordinates the action parameters of each component. In existing technologies, unwinding devices suffer from poor structural adaptability. Fixed unwinding shafts cannot adapt to different core sizes, requiring multiple specifications of air expansion shafts, increasing costs. Furthermore, insufficient concentricity during high-speed operation leads to film swaying and significant tension fluctuations. These problems restrict the automation level and production efficiency of bag making machines, necessitating a dynamically adjustable tension, quick material change, and structurally adaptable unwinding device. Utility Model Content
[0003] Firstly, the purpose of this utility model is to provide an unwinding device that improves the adaptability of the unwinding frame.
[0004] The above-mentioned technical objective of this utility model is achieved through the following technical solution: an unwinding device, including a base and an unwinding frame, wherein a support frame is provided on the base; the unwinding frame is provided on the support frame; the unwinding frame includes a support shaft; the support shaft is rotatably connected to the support frame; a tensioning mechanism is provided on the support shaft; the tensioning mechanism includes a sliding sleeve, a tensioning plate, a drive assembly, and an opening and closing assembly; the sliding sleeve is sleeved on the support shaft; the drive assembly drives the sliding sleeve to move axially upward relative to the support shaft; the sliding sleeve drives the tensioning plate away from or towards the support shaft through the opening and closing assembly.
[0005] Furthermore, a sliding frame is provided on the support shaft; a sliding groove is provided on the sliding frame; the opening and closing assembly includes a tensioning rib and a sleeve rib; the tensioning rib is located at the bottom of the tensioning plate; the sleeve rib is located on the outer surface of the sliding sleeve; a sliding limit block that cooperates with the sliding groove is provided on the tensioning rib; the tensioning rib and the sleeve rib are connected by a support connecting rod; both ends of the support connecting rod are hinged to the tensioning rib and the sleeve rib respectively.
[0006] Furthermore, there are at least two pairs of support links, with the two links of each pair of support links respectively located on both sides of the sleeve edge and the tensioning edge; the at least two pairs of support links are arranged at intervals along the axial direction of the sleeve edge.
[0007] Furthermore, the driving assembly includes a driving rod; one end of the driving rod is provided with an external thread; the support shaft is provided with an internal threaded hole that mates with the threaded end of the driving rod; the other end of the driving rod is provided with a first baffle and a second baffle; the driving rod passes through a force-receiving hole at the bottom of the sliding sleeve; the first baffle and the second baffle are located inside and outside the sliding sleeve, respectively, so that the sliding sleeve is clamped between the first baffle and the second baffle; when the driving rod is rotated, the helical transmission between the driving rod and the internal threaded hole drives the sliding sleeve, together with the first baffle and the second baffle clamping it, to move axially along the support shaft.
[0008] Furthermore, the drive assembly also includes a first planar bearing and a second planar bearing; both the first planar bearing and the second planar bearing are sleeved on the drive rod; the two ends of the first planar bearing abut against the first baffle and the sliding sleeve respectively; the two ends of the second planar bearing abut against the second baffle and the sliding sleeve respectively.
[0009] Furthermore, the outer surface of the support shaft is provided with a shaft groove; the inner surface of the sliding sleeve is provided with a sleeve rail that mates with the shaft groove.
[0010] Furthermore, a counterweight wheel is installed on the support shaft, and the counterweight wheel and the part with the tension plate are located on both sides of the support point of the sliding frame unwinding frame, respectively.
[0011] Secondly, this utility model provides a bag making machine that improves the adaptability of the unwinding frame.
[0012] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a bag making machine, wherein the bag making machine includes any of the unwinding devices described in the first aspect.
[0013] In summary, this utility model has the following beneficial effects:
[0014] Through the coordinated operation of the sliding sleeve, drive assembly, and opening / closing assembly of the tensioning mechanism, the tensioning plate can move radially away from or towards the support shaft, enabling rapid clamping and release of cores with different inner diameters. This design avoids the problem of traditional fixed unwinding shafts requiring multiple specifications of air expansion shafts, significantly reducing equipment costs and adapting to the unwinding needs of various types of roll materials. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the unwinding device in Embodiment 1.
[0016] Figure 2 This is a schematic diagram of the unwinding frame in Example 2.
[0017] Figure 3 This is a schematic diagram of the opening and closing component in Embodiment 2.
[0018] Figure 4 Example 3 is a schematic diagram of the drive rod.
[0019] In the diagram: 1. Base; 2. Support frame; 3. Unwinding frame; 4. Counterweight wheel; 5. Sliding frame;
[0020] 31. Support shaft; 32. Sliding sleeve; 33. Opening and closing assembly; 331. Sliding limit block; 332. Tensioning rib; 333. Sleeve rib; 334. Support connecting rod; 34. Tensioning plate; 35. Drive rod; 351. First baffle; 352. Second baffle; 353. First plane bearing; 354. Second plane bearing;
[0021] 41. Belt groove. Detailed Implementation
[0022] To make the technical problems, technical solutions and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.
[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to that other component. This "connection" is not limited to a fixed connection or a movable connection; the specific connection method should be determined based on the specific technical problem to be solved.
[0024] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0026] Example 1:
[0027] This embodiment provides an unwinding device that solves the problem of poor adaptability of existing unwinding devices. The unwinding device includes a base 1 and an unwinding frame 3. A support frame 2 is mounted on the base 1. The support frame 2 and the base 1 are in an L-shape. The unwinding frame 3 is mounted on the support frame 2. The main body of the unwinding frame 3 and the base 1 are on the same side of the support frame 2. The unwinding frame 3 includes a support shaft 31. The support shaft 31 is rotatably connected to the support frame 2. Optionally, the support shaft 31 and the support frame 2 are connected by a bearing.
[0028] A tensioning mechanism is provided on the support shaft 31; the tensioning mechanism includes a sliding sleeve 32, a tensioning plate 34, a drive assembly, and an opening and closing assembly 33. The sliding sleeve 32 is sleeved on the support shaft 31; the drive assembly drives the sliding sleeve 32 to move axially relative to the support shaft 31; the sliding sleeve 32 drives the tensioning plate 34 away from or towards the support shaft 31 through the opening and closing assembly 33.
[0029] Optionally, the drive assembly can be one of a lead screw, a hydraulic cylinder, or a servo motor. The drive assembly pushes the sliding sleeve 32 to move axially along the support shaft 31. The sliding sleeve 32 drives the tensioning plate 34 through the opening and closing assembly 33, converting the axial movement into radial displacement. When the sliding sleeve 32 moves towards the proximal end of the support shaft 31, the tensioning plate 34 expands outward, clamping the inner wall of the core; conversely, it contracts, releasing the core. The core changing steps are as follows: the drive assembly pushes out the sliding sleeve 32 → the tensioning plate 34 retracts → the old core is removed → the new core is inserted → the drive assembly retracts the sleeve → the tensioning plate 34 expands until it fits against the inner wall of the core.
[0030] Preferably, multiple tensioning plates 34 move radially in sync to ensure uniform distribution of clamping force and reduce swaying during high-speed rotation.
[0031] The beneficial technical effects of this embodiment are as follows: The radially adjustable design of the tension plate 34 supports cores of different inner diameters, eliminating the need to replace the air shaft or mandrel, thus reducing spare parts costs and downtime. The synchronous opening and closing of the tension plate 34 ensures concentricity of the clamping, preventing eccentric swaying of the roll material during high-speed operation and reducing tension fluctuations.
[0032] Example 2:
[0033] Based on Embodiment 1, this embodiment provides an unwinding device and gives a specific scheme for the opening and closing component 33 of the tensioning mechanism. A sliding frame 5 is provided on the support shaft 31; a sliding groove is provided on the sliding frame 5. The opening and closing component 33 includes a tensioning ridge 332 and a sleeve ridge 333; the tensioning ridge 332 is provided at the bottom of the tensioning plate 34; the sleeve ridge 333 is provided on the outer surface of the sliding sleeve 32; a sliding limiting block 331 that cooperates with the sliding groove is provided on the tensioning ridge 332. The sliding frame 5 is fixed on the support shaft 31, and its sliding groove provides an axial guide track for the sliding limiting block 331 on the tensioning ridge 332, restricting the tensioning plate 34 to move only radially and preventing skewing.
[0034] The tensioning rib 332 and the sleeve rib 333 are connected by a support rod 334; both ends of the support rod 334 are hinged to the tensioning rib 332 and the sleeve rib 333, respectively. The sliding frame 5 is fixed on the support shaft 31, and its sliding groove provides an axial guide track for the sliding limit block 331 on the tensioning rib 332, restricting the tensioning plate 34 to move only radially and preventing skewing. The sleeve rib 333 is fixed to the outer surface of the sliding sleeve 32 and hinged to the support rod 334, converting the axial movement of the sliding sleeve 32 into a change in the swing angle of the support rod 334. Both ends are hinged to the tensioning rib 332 and the sleeve rib 333, respectively, forming a "double-hinge four-bar linkage mechanism", converting the axial displacement of the sleeve rib 333 into the radial displacement of the tensioning rib 332. After the roll material is installed, the sliding frame 5 also serves to restrict the axial movement of the roll material.
[0035] Preferably, the sliding frame 5 is inclined at one end of the principle sliding sleeve 32, with an inclination angle of 1 to 5 degrees. The inclination angle facilitates the movement of the sliding limit block 331 within the sliding groove.
[0036] The opening and closing component 33 provided in this embodiment has the advantages of simple structure and easy maintenance.
[0037] Preferably, the unwinding device includes three to six tension plates 34 and a corresponding number of opening and closing components 33 as described above.
[0038] Preferably, there are at least two pairs of support rods 334, with two rods of each pair respectively disposed on both sides of the sleeve ridge 333 and the tensioning ridge 332; the at least two pairs of support rods 334 are arranged at intervals along the axial direction of the sleeve ridge 333. Through the synergistic effect of symmetrical force on both sides and multi-point axial support, the rigidity and motion synchronization of the tensioning mechanism are significantly improved, the risk of jamming caused by off-center loading is eliminated, and the concentricity and stability of the core clamping are ensured.
[0039] Example 3:
[0040] Based on Embodiment 2, this embodiment provides an unwinding device and gives a specific structure of the driving assembly. The driving assembly includes a driving rod 35; one end of the driving rod 35 is provided with an external thread; the support shaft 31 is provided with an internal threaded hole that mates with the threaded end of the driving rod 35; the other end of the driving rod 35 is provided with a first baffle 351 and a second baffle 352; the driving rod 35 passes through a force-receiving hole at the bottom of the sliding sleeve 32; the first baffle 351 and the second baffle 352 are respectively located inside and outside the sliding sleeve 32, so that the sliding sleeve 32 is clamped between the first baffle 351 and the second baffle 352. The first baffle 351 and the second baffle 352 are respectively located inside and outside the sliding sleeve 32, forming a "sandwich" structure, which forcibly transmits the axial movement of the driving rod 35 to the sliding sleeve 32 and avoids relative sliding.
[0041] When the drive rod 35 is rotated, the drive rod 35, in conjunction with the helical transmission of the internal threaded hole, drives the sliding sleeve 32, along with the first baffle 351 and the second baffle 352 that hold it, to move axially along the support shaft 31. As the core of power transmission, its external thread section forms a helical pair with the internal threaded hole of the support shaft 31, converting rotational input into axial output; the baffles at both ends form a mechanical clamping structure, transmitting axial force to the sliding sleeve 32. The thread helix angle is less than the friction angle, ensuring self-locking at any position without the need for an additional braking device.
[0042] Optionally, the drive lever 35 can be connected to a handwheel or power tool. The exposed end of the drive lever 35 has an interface that matches the handwheel or power tool.
[0043] The core innovation of this embodiment lies in the design of the threaded drive assembly. By using a helical pair, rotational motion is converted into axial displacement, achieving precise control of the tensioning mechanism. This eliminates the need for complex drive units such as cylinders and servo motors, reducing manufacturing costs. The threaded pair slips under overload conditions, preventing damage to the mechanism.
[0044] Example 4:
[0045] Based on Embodiment 3, this embodiment provides an unwinding device that solves the problem of hard friction between the first baffle 351, the second baffle 352, and the sliding sleeve 32. The drive assembly also includes a first planar bearing 353 and a second planar bearing 354; both the first planar bearing 353 and the second planar bearing 354 are sleeved on the drive rod 35; the two ends of the first planar bearing 353 abut against the first baffle 351 and the sliding sleeve 32, respectively; the two ends of the second planar bearing 354 abut against the second baffle 352 and the sliding sleeve 32, respectively. The core innovation of the first planar bearing 353 and the second planar bearing 354 lies in replacing sliding friction with rolling friction, thus solving the problem of device damage caused by hard friction between the baffles and the sliding sleeve 32.
[0046] Preferably, the outer surface of the support shaft 31 is provided with a shaft groove; the inner surface of the sliding sleeve 32 is provided with a sleeve rail that mates with the shaft groove. The grooved rail, which is arranged axially along the support shaft 31, serves as a mechanical guiding reference for the sliding sleeve 32. This restricts the sliding sleeve 32 to move only axially, preventing circumferential slippage or deflection.
[0047] Preferably, a counterweight wheel 4 is provided on the support shaft 31, and the counterweight wheel 4 and the part on which the tension plate 34 is installed are located on both sides of the support point of the unwinding frame 3 of the sliding frame 5. Installed on the support shaft 31 and located on the support point separately from the tension plate 34, the centrifugal force of the tension plate 34 is balanced by the gravitational torque to suppress vibration during high-speed rotation.
[0048] Preferably, the counterweight wheel 4 is provided with a belt groove 41, through which an external motor or other equipment can be connected to drive the support shaft 31 to rotate, or drive the damping mechanism to prevent the rotation speed from being too fast.
[0049] Example 5:
[0050] This embodiment of a bag-making machine for valve bags adopts a fully automated production line design, integrating five major process steps in sequence: unwinding, printing, cutting, folding, and sealing. Each step is synchronously linked through a servo system. The raw material roll is pulled into the printing device by the unwinding device. After the pattern is printed, it is conveyed to a high-speed slitting machine through a correction and length setting process. The cut pieces are mechanically folded to form the valve structure, and finally, the valve bag is formed by hot-pressing and sealing.
[0051] The unwinding device includes a base 1 and an unwinding frame 3. A support frame 2 is provided on the base 1. The unwinding frame 3 is provided on the support frame 2. The unwinding frame 3 includes a support shaft 31. The support shaft 31 is rotatably connected to the support frame 2. A tensioning mechanism is provided on the support shaft 31. The tensioning mechanism includes a sliding sleeve 32, a tensioning plate 34, a drive assembly, and an opening and closing assembly 33. The sliding sleeve 32 is sleeved on the support shaft 31. The drive assembly drives the sliding sleeve 32 to move axially relative to the support shaft 31. The sliding sleeve 32 drives the tensioning plate 34 away from or closer to the support shaft 31 through the opening and closing assembly 33. A sliding frame 5 is provided on the support shaft 31; a sliding groove is provided on the sliding frame 5; the opening and closing assembly 33 includes a tensioning rib 332 and a sleeve rib 333; the tensioning rib 332 is provided at the bottom of the tensioning plate 34; the sleeve rib 333 is provided on the outer surface of the sliding sleeve 32; a sliding limit block 331 that cooperates with the sliding groove is provided on the tensioning rib 332; the tensioning rib 332 and the sleeve rib 333 are connected by a support rod 334; the two ends of the support rod 334 are respectively hinged to the tensioning rib 332 and the sleeve rib 333. The driving assembly includes a driving rod 35; one end of the driving rod 35 is provided with an external thread; the support shaft 31 is provided with an internal threaded hole that mates with the threaded end of the driving rod 35; the other end of the driving rod 35 is provided with a first baffle 351 and a second baffle 352; the driving rod 35 passes through a force-receiving hole at the bottom of the sliding sleeve 32; the first baffle 351 and the second baffle 352 are located inside and outside the sliding sleeve 32, respectively, so that the sliding sleeve 32 is clamped between the first baffle 351 and the second baffle 352; when the driving rod 35 is rotated, the helical transmission of the driving rod 35 and the internal threaded hole drives the sliding sleeve 32, together with the first baffle 351 and the second baffle 352 clamping it, to move axially along the support shaft 31. The drive assembly also includes a first planar bearing 353 and a second planar bearing 354; both the first planar bearing 353 and the second planar bearing 354 are sleeved on the drive rod 35; the two ends of the first planar bearing 353 abut against the first baffle 351 and the sliding sleeve 32 respectively; the two ends of the second planar bearing 354 abut against the second baffle 352 and the sliding sleeve 32 respectively. A counterweight wheel 4 is provided on the support shaft 31, and the counterweight wheel 4 and the part on which the tension plate 34 is installed are located on both sides of the support point of the unwinding frame 3 of the sliding frame 5.
[0052] The valve bag making machine in this embodiment integrates five major process steps through a fully automated production line, and combines an innovative design with a high-precision unwinding device to achieve the following effects:
[0053] 1. The threaded drive rod and the double-plane bearing work together to reduce the coefficient of sliding friction, and the simple mechanical mechanism realizes the opening and closing of the tensioning device.
[0054] 2. The counterweight wheel and tension plate are placed on both sides of the support point to form a lever balance system, which reduces vibration during the unwinding process.
[0055] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.
Claims
1. An unwinding device, characterized in that: It includes a base and an unwinding frame, with a support frame mounted on the base; the unwinding frame is mounted on the support frame. The unwinding frame includes a support shaft; the support shaft is rotatably connected to a support frame; a tensioning mechanism is provided on the support shaft; the tensioning mechanism includes a sliding sleeve, a tensioning plate, a drive assembly, and an opening and closing assembly; the sliding sleeve is sleeved on the support shaft; the drive assembly drives the sliding sleeve to move axially upward relative to the support shaft; the sliding sleeve drives the tensioning plate away from or closer to the support shaft through the opening and closing assembly.
2. The unwinding device according to claim 1, characterized in that: A sliding frame is provided on the support shaft; a sliding groove is provided on the sliding frame; the opening and closing assembly includes a tensioning rib and a sleeve rib; the tensioning rib is located at the bottom of the tensioning plate; the sleeve rib is located on the outer surface of the sliding sleeve; a sliding limit block that cooperates with the sliding groove is provided on the tensioning rib; the tensioning rib and the sleeve rib are connected by a support connecting rod; both ends of the support connecting rod are hinged to the tensioning rib and the sleeve rib respectively.
3. The unwinding device according to claim 2, characterized in that: There are at least two pairs of support links, with two links of each pair of support links respectively located on both sides of the sleeve edge and the tensioning edge; the at least two pairs of support links are arranged at intervals along the axial direction of the sleeve edge.
4. The unwinding device according to claim 3, characterized in that: The driving assembly includes a driving rod; one end of the driving rod is provided with an external thread; the support shaft is provided with an internal threaded hole that mates with the threaded end of the driving rod; the other end of the driving rod is provided with a first baffle and a second baffle; the driving rod passes through a force-receiving hole at the bottom of the sliding sleeve; the first baffle and the second baffle are located inside and outside the sliding sleeve, respectively, so that the sliding sleeve is clamped between the first baffle and the second baffle; when the driving rod is rotated, the helical transmission between the driving rod and the internal threaded hole drives the sliding sleeve, together with the first baffle and the second baffle clamping it, to move axially along the support shaft.
5. The unwinding device according to claim 4, characterized in that: The drive assembly also includes a first planar bearing and a second planar bearing; both the first and second planar bearings are sleeved on the drive rod; the two ends of the first planar bearing abut against the first baffle and the sliding sleeve respectively; the two ends of the second planar bearing abut against the second baffle and the sliding sleeve respectively.
6. The unwinding device according to claim 5, characterized in that: The outer surface of the support shaft is provided with a shaft groove; the inner surface of the sliding sleeve is provided with a sleeve rail that mates with the shaft groove.
7. The unwinding device according to claim 6, characterized in that: A counterweight wheel is installed on the support shaft, and the counterweight wheel and the part with the tension plate are located on both sides of the support point of the sliding frame unwinding frame, respectively.
8. A bag-making machine, characterized in that: The bag making machine includes the unwinding device as described in claims 1 to 7.