A wrapping device for wrapping a film with a pre-stretching mechanism

Abstract

The utility model discloses a kind of wrapping film wrapping devices with pre-stretching mechanism, it is related to packaging machinery technical field.The utility model aims at the problem that traditional small piece film capsule package continuous rotation or straight sending leads to tension change with film roll, lap joint and cutter position are not synchronous, easy to wrinkle and high film, linear feed, indexing rotation, extrusion pre-stretching scheme is proposed;Structure is left on main body and is equipped with support seat and is equipped with winding film roll, central guide groove is formed, and object carrying turntable can slide and rotate, its outer periphery is equipped with annular compression ring and film band extrusion channel, lower right drive motor is equipped with single side tooth fan-shaped gear and turntable bottom closed loop meshing chain indexing engagement, front end cutter fixed point cutting;Realize that winding circle and cutter position are stably corresponding, tension and pre-stretching are more uniform under the constraint of structure, significantly reduce film and broken film, and improve the consistency of adhesion and tempo.

Description

Technical Field

[0001] This utility model relates to the field of packaging machinery technology, specifically a wrapping device with a pre-stretching mechanism. Background Technology

[0002] Stretch film packaging is widely used in e-commerce logistics, food and daily chemicals, hardware and home appliances, and other scenarios. Typical processes include manual wrapping, semi-automatic, and fully automatic wrapping machines. Common equipment types include rotary table type, ring type, and rocker arm type. There are also film bladder processes for small and irregularly shaped items, where the film is first unfolded and stretched to form an opening, and then the item is fed in and sealed. To reduce film usage and improve adhesion, the industry generally uses methods such as friction damping or differential stretching for pre-stretching, and uses linear conveyors, turntables, or clamping unfolding components to achieve wrapping and sealing. Existing LED street light control devices based on the ZigBee system (publication number: CN214851897U) have the following drawbacks and require further improvement.

[0003] Traditional equipment uses continuous rotation or continuous linear conveying. The timing of the operation is not well coordinated with the film cutting and discharge positions, resulting in unstable overlap layers and positions, and wrinkles easily forming at the edges and corners. Tension mainly relies on film roll braking or friction damping, which is easily affected by changes in film roll diameter, operator adjustment habits, and ambient temperature and humidity, leading to fluctuations in pre-stretch ratio, higher film consumption, and increased risk of film breakage. Cutting often uses general-purpose cold or hot knives. If a stable relative motion relationship is not formed with the conveying and rotation, it is easy to produce fraying, rough edges, or weak sealing, affecting the appearance and reliability of the packaging.

[0004] In addition, the efficiency of the solution that relies on a fixed opening and manual closing is limited by the skill level of the personnel and has poor consistency; the solution that adopts pure linear propulsion without effective indexing rotation is difficult to form a sufficient and uniform number of winding turns within a limited stroke; the complex structure of multi-axis servo coordination introduced for synchronization brings about increased costs and maintenance difficulties. Utility Model Content

[0005] The main objective of this invention is to provide a wrapping device for a stretch film with a pre-stretching mechanism, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a wrapping device for a stretching film with a pre-stretching mechanism, wherein a support base is fixedly connected to the upper left side of the main body, and a stretching film roll is rotatably mounted on the support base; a guide rail groove is formed in the middle of the main body along the front-back direction, and a carrying turntable is slidably engaged with the guide rail groove relative to the main body through a sliding fit structure provided at its bottom and can move along the front-back direction, and the carrying turntable is rotatably connected to the main body through a central rotating shaft; an annular clamping ring is coaxially sleeved on the outer periphery of the carrying turntable, and the annular clamping ring is used to engage with the wrapping film. The film roll is extruded and pre-stretched; a drive motor is fixedly installed on the lower right side of the main body, and the output shaft of the drive motor is fixedly connected to a gear. The gear meshes with a chain located at the bottom of the turntable to drive the turntable to rotate intermittently in the circumferential direction as it moves along the guide rail groove. The gear's tooth ring has teeth on only one side of its circumference to form an indexing mesh with the chain; a cutter is fixedly installed at the front end of the main body along the moving path of the turntable and is opposite to the running path of the film roll on the turntable to cut the film roll after wrapping.

[0007] Preferably, the guide rail groove is a closed rectangular cross-section groove arranged in the front-to-back direction, with a groove width W6 of 20-40mm and a groove depth H6 of 8-20mm. The bottom of the cargo turntable is integrally formed with a rectangular slider, which is slidably connected to the guide rail groove with a fitting gap of 0.10-0.30mm. A limiting step is provided at each of the front and rear ends of the guide rail groove to abut against the corresponding shoulder on the bottom surface of the cargo turntable to limit its movement stroke.

[0008] Preferably, the gear is a sector-shaped tooth segment structure with teeth only on a section of the circumference, and the central angle of the toothed arc is 90° to 180°, the tooth width is 8 to 15 mm, and the module m is 1.5 to 2.5. The two ends of the tooth segment are provided with chamfers of R0.2 to R0.5 and are arranged in the same horizontal plane as the meshing chain to form indexing meshing.

[0009] Preferably, the meshing chain is a closed-loop link embedded in an annular chain groove opened circumferentially on the bottom surface of the turntable. The groove width is 0.10 to 0.50 mm larger than the nominal width of the chain, and the closed connection of the chain is located in the area corresponding to the toothless arc. The meshing chain is pressed against the bottom of the chain groove by fastening screws through two threaded holes on the bottom surface of the turntable to prevent movement.

[0010] Preferably, the annular clamping ring is coaxially formed by an inner metal base ring and an outer polyurethane coating layer, and has an arc-shaped cross section. The annular clamping ring is fixedly connected to the loading turntable by three to six countersunk screws evenly distributed along the circumference and is positioned relative to it with a coaxiality of 0.20 to 0.80 mm. The outer edge radius of the annular clamping ring is R1 to R3.

[0011] Preferably, the drive motor is fixed on the motor mounting plate on the lower right side of the main body and connected by four M8 to M12 bolts. The center distance between the output shaft of the drive motor and the gear is 30 to 80 mm, and the side clearance between the gear and the meshing chain at the meshing point is 0.05 to 0.20 mm. The axial distance between the gear and the bottom surface of the load turntable is 3 to 15 mm to ensure that the gear and the meshing chain are located on the same meshing plane.

[0012] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes a gear with teeth on only one side of its circumference that meshes with an indexing chain, creating a rotating-stopping rhythm as the turntable is fed linearly along the guide rail. The start and end positions of the wrapping ring stably correspond to the cutting position of the cutter, avoiding the overlap and film-cutting position drift caused by traditional continuous motion. Simultaneously, the annular pressing ring and the film strip led out from the wound film roll form a stable extrusion channel. The pre-stretch ratio is determined by the structure and does not fluctuate significantly with the film roll diameter or operator habits. The winding tension is uniform, reducing the risk of wrinkling and film breakage. There are no obvious fraying or burrs at the sealing point, improving the appearance and fit of the finished product.

[0013] This invention employs a simplified solution of drive motor + mechanical indexing to achieve a multi-turn and uniform winding trajectory without the need for multi-axis servo coordination. The combined motion of linear feeding and intermittent rotation allows the device to form a sufficient number of turns and stable overlap within a limited stroke, reducing reliance on manual closing and skill level, ensuring consistent rhythm and low labor intensity. The entire machine is based on common components such as support bases and guide rails, making connection and maintenance simple and cost-effective. Furthermore, by mechanically adjusting the indexing angle and clamping preload, it can accommodate materials of different specifications, improving the applicability and operational stability of the equipment. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present utility model. Figure 1 ; Figure 2 This is a schematic diagram of the overall structure of the present utility model. Figure 2 ; Figure 3 This is an enlarged view of part A of the present invention; Figure 4 This is a top view of the overall structure of this utility model.

[0015] In the diagram: 1. Main body; 2. Loading turntable; 3. Support base; 4. Stretch film roll; 5. Drive motor; 6. Guide rail groove; 7. Meshing chain; 8. Gear; 9. Cutter; 10. Annular clamping ring. Detailed Implementation

[0016] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0017] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] Example Please see Figure 1-4 This utility model provides a technical solution: A wrapping device for stretch film with a pre-stretching mechanism includes a support base 3 fixedly connected to the upper left side of a main body 1, on which a stretch film roll 4 is rotatably mounted; a guide rail groove 6 is formed in the middle of the main body 1 along the front-to-back direction; a carrying turntable 2 is slidably engaged with the guide rail groove 6 relative to the main body 1 through a sliding fit structure at its bottom and can move along the front-to-back direction; the carrying turntable 2 is rotatably connected to the main body 1 through a central rotating shaft; an annular clamping ring 10 is coaxially sleeved on the outer periphery of the carrying turntable 2, and the annular clamping ring 10 is used to compress the film strip led out from the stretch film roll 4. The main body 1 is pre-stretched; a drive motor 5 is fixedly installed on the lower right side of the main body 1, and the output shaft of the drive motor 5 is fixedly connected to a gear 8. The gear 8 meshes with a meshing chain 7 set at the bottom of the turntable 2 to drive the turntable 2 to generate intermittent circumferential rotation during its movement along the guide rail groove 6. The gear 8 has teeth on only one side of its circumference to form an indexing mesh with the meshing chain 7; a cutter 9 is fixedly installed at the front end of the main body 1 along the moving path of the turntable 2 and is opposite to the running path of the film strip on the turntable 2 to cut the film strip after wrapping.

[0020] The upper left side of the main body is fixed with a support base by bolts, on which a wound film roll is rotatably mounted; a closed rectangular section guide rail groove is opened in the middle of the main body along the front-to-back direction, and the bottom of the loading turntable is provided with a sliding structure that cooperates with the guide rail groove and is rotatably connected to the main body through its central stepped rotating shaft, and an annular clamping ring is coaxially fixed to the outer periphery of the loading turntable; a drive motor is fixedly installed on the lower right side of the main body, and its output shaft is fixedly connected to a sector-shaped gear, which is located on the same meshing plane as the closed-loop meshing chain embedded in the annular chain groove on the bottom surface of the loading turntable; a cutter is fixedly installed at the front end of the main body along the travel direction of the guide rail groove, and the height relationship between the blade and the loading turntable table surface meets the micro-cutting requirements.

[0021] The film strip drawn from the wound film roll forms a stable extrusion channel between the outer circumference of the turntable and the opposing surface of the annular clamping ring. The film strip is thinned and pre-stretched through this channel. The pre-stretched film has a tendency to spring back and shrink, providing continuous adhesion at subsequent closure and overlap. The drive motor drives the gear to rotate. When the toothed arc of the gear enters the contact area with the meshing chain, the gear and chain engage, driving the turntable to rotate circumferentially. When the gear rotates to the toothless arc area, it disengages from the chain, and the turntable stops rotating and only moves forward along the guide rail groove, thus realizing intermittent indexing motion of rotating a section and stopping a section.

[0022] During operation, the material to be wrapped is placed on the turntable, so that the head of the film belt is pressed against the side wall of the material through the annular clamping ring. The operator pushes the turntable forward along the guide rail groove. When the turntable moves to the meshing area corresponding to the toothed arc of the gear, the turntable starts to rotate and moves forward at the same time, and the film belt forms a spiral winding around the material. After passing the toothed area, the turntable stops at the indexing point and only keeps moving forward in a straight line to stabilize the position of the overlapping layer. With the repeated rotation and stop cycle, the film belt is stacked on the outer circumference of the material in multiple turns, at equal intervals and with equal tension, and is continuously stretched and shaped in the squeezing channel of the annular clamping ring.

[0023] When the cargo turntable is fed to the cutting position at the front of the main body, the film strip is cut and torn by the cutter blade. The previously formed overlap is tightly bonded by the self-adhesion and pre-stretching rebound of the film. The cargo turntable continues to be fed to the discharge port to complete one packaging cycle. The next cycle begins after the new film head is bonded at the annular pressing ring.

[0024] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A wrapping device for wrapping a film with a pre-stretching mechanism, comprising a main body (1) and a carrier turntable (2), characterized in that: A support base (3) is fixedly connected to the upper left side of the main body (1), and a winding film roll (4) is rotatably mounted on the support base (3); a guide rail groove (6) is opened in the middle of the main body (1) along the front-back direction, and the loading turntable (2) slides relative to the main body (1) through a sliding fit structure provided at its bottom and is rotatably connected to the main body (1) through a central rotating shaft; an annular clamping ring (10) is coaxially sleeved on the outer periphery of the loading turntable (2), and the annular clamping ring (10) is used to squeeze and fit with the film strip led out from the winding film roll (4) to form a pre-stretch; A drive motor (5) is fixedly installed on the lower right side of the main body (1). The output shaft of the drive motor (5) is fixedly connected to a gear (8). The gear (8) meshes with a meshing chain (7) set at the bottom of the turntable (2) to drive the turntable (2) to generate intermittent circumferential rotation during its movement along the guide rail groove (6). The gear (8) has teeth on only one side of its circumference to form an indexing mesh with the meshing chain (7). A cutter (9) is fixedly installed at the front end of the main body (1) along the moving path of the turntable (2) and is opposite to the running path of the film strip on the turntable (2) to cut the film strip after wrapping.

2. A wrapping apparatus for stretch wrap film having a pre-stretching mechanism as defined in claim 1, characterized in that: The guide rail groove (6) is a closed rectangular cross-section groove arranged in the front-back direction with a groove width W6 of 20-40mm and a groove depth H6 of 8-20mm. The bottom of the cargo turntable (2) is integrally formed with a rectangular slider, which is connected to the guide rail groove (6) with a sliding fit gap of 0.10-0.30mm. A limiting step is opened at the front and rear ends of the guide rail groove (6) to abut against the corresponding shoulder on the bottom surface of the cargo turntable (2) to limit its movement stroke.

3. A wrapping apparatus for stretch wrap film having a pre-stretching mechanism as defined in claim 1, characterized in that: The gear (8) is a sector-shaped tooth segment structure with teeth set only in one part of the circumference, and the central angle of the toothed arc is 90° to 180°, the tooth width is 8 to 15 mm, and the module m is 1.5 to 2.

5. The two ends of the tooth segment are provided with chamfers of R0.2 to R0.5 and are arranged in the same horizontal plane as the meshing chain (7) to form indexing meshing.

4. The wrapping apparatus according to claim 1, wherein: the pre-stretching mechanism is a pair of rollers. The meshing chain (7) is a closed-loop chain link and is embedded in the annular chain groove opened circumferentially on the bottom surface of the turntable (2). The width of the annular chain groove is 0.10 to 0.50 mm larger than the nominal width of the chain, and the closed connection of the chain is located in the area corresponding to the toothless arc. The meshing chain (7) is pressed against the bottom of the chain groove by fastening screws through two threaded holes on the bottom surface of the turntable (2) to prevent movement.

5. A wrapping apparatus for stretch wrap film having a pre-stretching mechanism as defined in claim 1, wherein: The annular clamping ring (10) is coaxially formed by an inner metal base ring and an outer polyurethane coating layer and has a circular arc cross section. The annular clamping ring (10) is fixedly connected to the loading turntable (2) by three to six countersunk screws evenly distributed along the circumference and is positioned relative to it with a coaxiality of 0.20 to 0.80 mm. The outer edge radius of the annular clamping ring (10) is R1 to R3.

6. A wrapping apparatus for stretch wrap film having a pre-stretching mechanism as defined in claim 1, characterized in that: The driving motor (5) is fixed on the motor mounting plate at the lower right side of the main body (1) and connected by four M8-M12 bolts, the center distance between the output shaft of the driving motor (5) and the gear (8) is 30-80 mm, the side gap of the gear (8) and the meshing chain (7) at the meshing position is 0.05-0.20 mm, and the axial distance of the gear (8) relative to the bottom surface of the object turntable (2) is 3-15 mm to ensure that the gear (8) and the meshing chain (7) are located in the same meshing plane.

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