Double-chain gripper conveyor for vacuum packaging machines

Abstract

The utility model discloses a double chain clamping conveying device of vacuum packaging machine belongs to vacuum packaging equipment technical field. To solve the problem of the existing vacuum packaging machine film is easy to independent shrink misplacement in the vacuumizing, heat sealing process, and the film body shrinkage is easy to extrude material inward, cause material breakage, the utility model is corresponded film roll material, film roll material position respectively sets up independent double chain clamping conveying mechanism in the frame. The utility model discloses the chain wheel of inclination setting is guided to the film body edge and expands outward, and the curved surface protruding of cooperation opening clamping cam makes the clamping part progressive opening clamping, realizes the film edge depth clamping positioning of up and down film, and simultaneously utilizes the steering transmission shaft assembly of work station both sides cooperation chain traction, and the film body edge is continuously pulled outward and is tensioned after clamping, and the film body shrinkage stress that is brought about by active offset negative pressure, high temperature, effectively inhibits the film body excessive shrinkage. Significantly improve the vacuum packaging forming precision and product yield, and the equipment operation is stable, and the versatility is strong.

Description

Technical Field

[0001] This utility model relates to the field of vacuum packaging machines, specifically to a double-chain clamping and conveying device for a vacuum packaging machine. Background Technology

[0002] Vacuum packaging machines are widely used in sealing and packaging operations in the food, light industry, and industrial products fields. The conventional working process is as follows: the upper and lower packaging films are continuously transported to the forming station, material filling station, and vacuum heat sealing station through the traction conveyor structure, and the processes of film forming, material placement, vacuum extraction, heat sealing and bonding, and finished product output are completed in sequence.

[0003] Existing vacuum packaging machines generally use a conventional roller traction conveying method for film transport. This conveying structure can only achieve passive dragging of the film, which has significant technical defects in actual production: During the vacuuming process, the film will shrink and deform inward due to the negative pressure suction of the cavity; during the heat sealing process, the film will further shrink and deform due to high temperature and pressure, and the shrinkage amplitude and position of the upper and lower films cannot be kept synchronized. On the one hand, the disordered shrinkage of the film will directly cause misalignment and displacement of the upper and lower film edges, resulting in skewed heat sealing lines and uneven sealing widths, which can easily lead to quality defects such as incomplete sealing, missing sealing, and sealing wrinkles, seriously reducing the packaging sealing performance and product appearance quality; on the other hand, excessive inward shrinkage of the film will directly squeeze the material filled inside the station. For fragile, soft, and easily deformable materials, this can easily cause material compression damage, deformation, and displacement, significantly reducing the product packaging yield.

[0004] There is currently no technical solution to address the above problems. Conventional conveying structures cannot effectively limit, deeply clamp, and actively tension the membrane edge, cannot offset the membrane shrinkage stress under negative pressure and high temperature conditions, and cannot fundamentally suppress membrane shrinkage deformation. As a result, there are always problems such as poor membrane alignment accuracy, unstable sealing quality, and easy damage to materials. The equipment adaptability and production stability are also poor. Utility Model Content

[0005] To address the aforementioned problems, the purpose of this utility model is to overcome the shortcomings of the existing technology and solve the technical problems of the upper and lower films of existing vacuum packaging machines easily shrinking on their own during the vacuuming and heat sealing process, resulting in poor alignment accuracy, leading to sealing quality defects, and the film shrinkage easily squeezing the material inward, causing material damage and deformation.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a double-chain clamping and conveying device for a vacuum packaging machine, wherein independent double-chain clamping and conveying mechanisms are set for the upper and lower films respectively, so as to realize separate upper and lower film clamping and conveying with high precision and anti-shrinkage.

[0007] The overall equipment frame carries upper and lower film rolls. Each film roll corresponds to a double-chain clamping and conveying mechanism. The double-chain clamping and conveying mechanism mainly consists of two sets of oppositely arranged circular chains, multiple sets of drive shaft assemblies, and evenly distributed clamping components. The clamping components are evenly fixed on the inner sides of the two sets of circular chains, and closed-loop continuous conveying is achieved by driving multiple sets of drive shaft assemblies. The drive shaft assemblies are divided into opening clamping conveyor shaft assemblies and steering conveyor shaft assemblies with different functions. The opening clamping conveyor shaft assemblies are set at the feeding end and the discharging end to realize automatic film loading and clamping and finished product unloading and loosening. The steering conveyor shaft assemblies are arranged on both sides of the forming station and the vacuum heat sealing station to realize chain steering guidance and film outer tension limit.

[0008] The clamping components employ an elastic opening and closing structure, consisting of a stationary clamping block fixed to the chain and a vertically sliding movable clamping block. A compression spring is installed between the stationary and movable clamping blocks, maintaining the clamping state under normal conditions thanks to the spring force. The clamping conveyor shaft assembly at the feeding end is equipped with an inclined sprocket and an clamping cam. The inclined sprocket automatically guides the edge of the film during the conveying process, allowing the edge of the film to enter the optimal clamping position. Combined with the continuous curved surface protrusion structure of the clamping cam, the clamping components gradually open sequentially, achieving deep clamping and positioning of the film edge, avoiding the problems of easy displacement and loosening caused by traditional shallow clamping. After the film enters the forming, vacuuming, and heat-sealing stations, the steering conveyor shaft assembly has no clamping structure, keeping the clamping components in a clamped state throughout the process. At the same time, relying on the chain traction and the guiding action of the steering conveyor shaft, an outward pulling tension is continuously applied to the edge of the film, actively counteracting the film shrinkage stress generated by negative pressure adsorption and high-temperature hot pressing, thus limiting excessive film shrinkage at its source. The two sets of clamping and conveying mechanisms corresponding to the upper and lower films operate synchronously and at the same speed, ensuring that the clamping, tensioning, and conveying states of the upper and lower films are completely consistent, and achieving precise alignment throughout the process.

[0009] The beneficial effects of this utility model are: First, this utility model adopts an inclined sprocket guide expansion combined with a cam progressive opening clamping structure to achieve deep clamping and positioning of the upper and lower film edges, completely solving the defects of easy displacement and loosening of traditional shallow clamping methods, ensuring precise alignment of the upper and lower films throughout the process, effectively eliminating quality problems such as edge skewing, missing sealing, and wrinkles, and greatly improving the packaging sealing accuracy and sealing reliability.

[0010] Secondly, this utility model uses a steering transmission shaft assembly in conjunction with chain traction to continuously pull and tension the edge of the membrane outward, which can actively counteract the shrinkage stress of the membrane under vacuum and heat sealing conditions, effectively suppress excessive inward shrinkage of the membrane, completely avoid the situation of the membrane squeezing the internal material, play a good protective role for fragile, soft and easily deformable materials, and significantly improve the product yield.

[0011] Third, this utility model adopts a linkage structure of spring elastic constant clamping and cam automatic progressive clamping, the opening and closing action is smooth and continuous without impact or jamming, and the entire process of feeding clamping, station tensioning and conveying, and discharging clamping is completed automatically, with high operational stability; the two types of transmission shaft components have clear functional divisions, simple and durable structure, and are suitable for continuous industrial production.

[0012] Fourth, the upper and lower films are independently and synchronously conveyed and tensioned, which can adapt to the production needs of packaging films of different widths and materials. The equipment is highly versatile and fundamentally solves the industry pain points of existing vacuum packaging machines, such as uncontrolled film shrinkage, unstable forming quality, and easy damage to materials.

[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0014] Figure 1 This is an application structure diagram of a specific embodiment of the present utility model; Figure 2 This is a partial three-dimensional structural view of a specific embodiment of the present utility model; Figure 3 This is a side view of the clamping component in a specific embodiment of the present utility model; Figure 4 This is a cross-sectional view of the clamping conveyor shaft assembly in a specific embodiment of this utility model.

[0015] Explanation of reference numerals in the attached drawings: 1. Circulating chain; 2. Clamping component; 3. Clamping transmission shaft assembly; 31. Transmission shaft; 32. Sprocket; 33. Clamping cam; 4. Steering transmission shaft assembly; 5. Stationary clamping block; 51. Side plate; 52. Guide protrusion; 53. Stationary clamping plate; 6. Moving clamping block; 61. Moving clamping plate; 62. Vertical guide plate; 63. Vertical guide groove; 64. Spring mounting post; 65. Clamping edge; 7. Compression spring. Detailed Implementation

[0016] The present invention will be described in detail below through embodiments, which are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention.

[0017] like Figure 1 — Figure 4 As shown, this embodiment discloses a double-chain clamping conveyor for a vacuum packaging machine. The main body of the equipment includes a frame, on which an upper film roll and a lower film roll are mounted. A set of double-chain clamping conveyors is installed on the output paths of the upper film roll and the lower film roll, respectively. The two sets of double-chain clamping conveyors start and stop synchronously and operate at the same speed, respectively completing the precise guidance, deep clamping, and anti-shrinkage tensioning conveying operations of the upper and lower films.

[0018] The dual-chain clamping conveying mechanism includes two sets of horizontally and parallelly arranged circular chains 1, multiple sets of drive shaft assemblies, and several clamping components 2. Several clamping components 2 are evenly arranged and fixed along the conveying direction on the inner sidewalls of the two sets of circular chains 1, and all clamping components 2 move synchronously with the circular chains 1. The two sets of circular chains 1 are together sleeved on the outside of each set of drive shaft assemblies, forming a closed-loop circular conveying structure driven by the drive shaft assemblies to achieve continuous membrane conveying.

[0019] The drive shaft assembly is divided into an opening clamping conveyor shaft assembly 3 and a steering conveyor shaft assembly 4, with a total of no less than three sets of drive shaft assemblies. Among them, one set of opening clamping conveyor shaft assembly 3 is set at the film feeding end and the finished product discharge end, respectively, to realize the film feeding depth clamping and the finished product discharge automatic loosening; steering conveyor shaft assemblies 4 are set on the left and right sides of the packaging forming station and the vacuum heat sealing station, respectively, to turn, tension and guide the surrounding chain 1, and to cooperate with the chain traction to realize the pulling limit of the outer edge of the film.

[0020] The clamping component 2 includes a stationary clamping block 5 and a movable clamping block 6 that cooperate with each other. The outer side of the stationary clamping block 5 is fixedly connected to the chain link surrounding the chain 1 to ensure that the clamping component 2 moves synchronously with the chain. The stationary clamping block 5 has vertically arranged side plates 51 symmetrically fixed on its left and right sides. The inner sidewalls of the two side plates 51 are integrally formed with guide protrusions 52. A stationary clamping plate 53 is horizontally fixed between the upper ends of the two side plates 51. The stationary clamping plate 53 forms the lower clamping reference surface of the clamping structure.

[0021] The movable clamping block 6 includes a horizontally arranged movable clamping plate 61. Vertical guide plates 62 extend upward from both ends of the movable clamping plate 61. A through vertical guide groove 63 is provided on the vertical guide plate 62. The guide protrusion 52 on the stationary clamping block 5 is slidably embedded in the vertical guide groove 63, so that the movable clamping block 6 as a whole can make a stable vertical lifting and lowering movement along the guide protrusion 52, effectively avoiding deviation and jamming during the clamping process.

[0022] The upper ends of the two vertical guide plates 62 are bent inward and joined together to form an integral structure. A vertical spring mounting post 64 is fixedly installed at the joined position, and a compression spring 7 is vertically sleeved on the outside of the spring mounting post 64. The upper end of the compression spring 7 abuts against the inner side wall of the upper end of the vertical guide plate 62, and the lower end abuts against the upper end face of the stationary clamping plate 53. When no external force is applied, the compression spring 7 continuously presses down on the vertical guide plate 62, causing the moving clamping plate 61 to press down, so that the moving clamping plate 61 and the stationary clamping plate 53 are tightly fitted together, maintaining a normal clamping state.

[0023] The front end of the moving clamping plate 61 is bent downward to form a clamping edge 65. The clamping edge 65 and the front end of the stationary clamping plate 53 cooperate to form a clamping opening, which is used to stably clamp the edge areas of the upper and lower films. The clamping force is uniform and will not scratch or damage the packaging film.

[0024] The clamping conveyor shaft assembly 3 includes a conveyor shaft 31, a sprocket 32, and an opening cam 33. The sprocket 32 ​​is obliquely mounted at the end of the conveyor shaft 31 and meshes with the surrounding chain 1 for transmission. The obliquely mounted sprocket 32 ​​can automatically guide and expand the edges of the upper and lower films during chain conveying, allowing the film edges to be opened to a suitable clamping position. The opening cam 33 is fixedly installed on the conveyor shaft 31 near the sprocket 32 ​​and is arranged accordingly along the movement trajectory of the clamping component 2. The opening cam 33 adopts a continuous smooth curved surface protrusion structure. When the clamping component 2 moves with the surrounding chain 1 past the position of the opening cam 33, the moving clamping block 6 gradually slides and rises along the cam's protruding curved surface, and the clamping jaws gradually open, which can stably and accurately clamp the deeper positions of the upper and lower film edges, achieving deep positioning clamping and completely avoiding the problems of easy loosening and displacement of traditional shallow clamping. When the clamping component 2 leaves the cam's pushing range, the compression spring 7 quickly returns to its original position, and the clamping jaws lock the film edges, completing stable clamping.

[0025] The steering transmission shaft assembly 4 is structurally similar to the clamping transmission shaft assembly 3, but differs in that the sprocket of the steering transmission shaft assembly 4 adopts a coaxial horizontal arrangement without any tilt angle, and is not equipped with the clamping cam 33. The steering transmission shaft assembly 4 only serves to steer, tension, and guide the chain 1, ensuring that the clamping component 2 remains clamped throughout the entire process. During the entire process of the membrane entering the forming station and the vacuum heat sealing station for processing, the steering transmission shaft assembly 4, with its guiding and limiting function and the continuous traction of the chain 1, continuously applies outward tensile tension to the deeply clamped upper and lower membrane edges, actively counteracting the shrinkage stress generated by the membrane under negative pressure adsorption and high-temperature hot pressing conditions. This effectively limits the excessive inward shrinkage of the membrane, ensuring precise alignment of the upper and lower membrane edges throughout the process, and completely preventing the membrane from shrinking and squeezing the internal material, thus eliminating material damage and deformation problems.

[0026] The working process of this utility model is as follows: After the equipment is started, the upper and lower film rolls are output simultaneously as packaging film. The edge of the film is conveyed to the feeding end clamping conveyor shaft assembly 3. The inclined sprocket 32 ​​guides the edge of the film to expand outward. At the same time, the curved structure of the clamping cam 33 gradually opens the clamping jaws of the clamping component 2. The gradually opening jaws accurately clamp the deep edge of the film. After the film is clamped, it is released from the cam's action area, and the compression spring 7 resets and locks the clamping state. Then, the chain 1 drives the film to move at a constant speed. It is guided by the two-sided turning conveyor shaft assemblies 4 into the forming, vacuuming, and heat-sealing stations. Throughout the process, the outer edge of the film is stretched and tightened to counteract the shrinkage stress of the film, ensuring that the film shape is stable, the alignment is accurate, and there is no shrinkage misalignment or material compression. After the heat sealing process is completed, the film is conveyed to the discharge end clamping conveyor shaft assembly 3, and the clamping mouth is gradually opened again by the clamping cam 33 to loosen the edge of the film. Finally, the formed packaging film is automatically discharged in conjunction with the conveyor belt. The whole process is continuous and stable, with high forming accuracy and high yield.

Claims

1. A double-chain clamping and conveying device for a vacuum packaging machine, comprising a frame, wherein an upper film roll and a lower film roll are disposed on the frame, characterized in that: A set of double-chain clamping conveyor mechanisms are respectively installed on the output paths of the upper and lower film rolls; the double-chain clamping conveyor mechanism includes two sets of oppositely arranged circular chains (1), several drive shaft assemblies and several clamping components (2), the clamping components (2) are evenly fixed on the opposite side walls of the two sets of circular chains (1), and the two sets of circular chains (1) achieve closed-loop circular conveying through the cooperation of several drive shaft assemblies; the drive shaft assembly includes an opening clamping conveyor shaft assembly (3) and a turning conveyor shaft assembly (4), the opening clamping conveyor shaft assembly (3) is respectively set at the feed end and the discharge end of the film body, and the turning conveyor shaft assembly (4) is arranged on both sides of the forming station and the vacuum heat sealing station; the clamping component (2) includes a stationary clamping block (5) fixed to the circular chain (1) and a moving clamping block (6) vertically guided and assembled on the stationary clamping block (5), and a compression for maintaining normal clamping is assembled between the stationary clamping block (5) and the moving clamping block (6). Spring (7); The clamping conveyor shaft assembly (3) includes a conveyor shaft (31), a sprocket (32) inclinedly meshing with the conveyor shaft (31), and a clamping cam (33) fixed on the conveyor shaft (31). The inclined sprocket (32) can guide the upper and lower film edges outward. The clamping cam (33) is located near the sprocket (32). The clamping cam (33) has a continuous convex curved surface, which allows the clamping jaws of the passing clamping components (2) to open gradually in sequence. This achieves deep clamping of the upper and lower membrane edges, and the opening cam (33) can push the clamping block (6) to overcome the elastic force of the compression spring (7) to open the clamping opening; the steering transmission shaft assembly (4) adopts a coaxial transmission shaft and sprocket structure and is not equipped with an opening cam (33). The steering transmission shaft assembly (4) works with the surrounding chain (1) to pull and tighten the upper and lower membrane edges after clamping and fixing, thereby offsetting the membrane shrinkage stress under negative pressure and high temperature conditions and limiting the membrane from excessively shrinking inward.

2. The double-chain clamping and conveying device for a vacuum packaging machine according to claim 1, characterized in that: The static clamping block (5) has side plates (51) fixed symmetrically on both sides, and guide protrusions (52) are provided on the inner sidewalls of the side plates (51) on both sides. A static clamping plate (53) is fixedly installed between the upper ends of the side plates (51) on both sides.

3. The double-chain clamping and conveying device for a vacuum packaging machine according to claim 2, characterized in that: The movable clamping block (6) includes a movable clamping plate (61), and vertical guide plates (62) are symmetrically arranged on both sides of the movable clamping plate (61). A vertical guide groove (63) is opened on the vertical guide plate (62), and the guide protrusion (52) is slidably embedded in the vertical guide groove (63) to form a vertical sliding guide fit.

4. The double-chain clamping and conveying device for a vacuum packaging machine according to claim 3, characterized in that: The upper ends of the vertical guide plates (62) on both sides are bent inward and joined together to form an integral structure. A spring mounting post (64) is fixedly installed at the joined position. The compression spring (7) is sleeved on the outside of the spring mounting post (64). The upper end of the compression spring (7) abuts against the vertical guide plate (62), and the lower end abuts against the upper surface of the static clamping plate (53).

5. The double-chain clamping and conveying device for a vacuum packaging machine according to claim 3, characterized in that: The front end of the moving clamp (61) is bent downward to form a clamping edge (65), and the clamping edge (65) cooperates with the stationary clamp (53) to form a clamping opening for clamping and fixing the edge of the membrane.

6. The double-chain clamping and conveying device for a vacuum packaging machine according to claim 1, characterized in that: The number of drive shaft assemblies shall not be less than three sets, of which one set of clamping conveyor shaft assembly (3) shall be arranged at the feeding end and the discharging end, and the remaining drive shaft assemblies shall be steering conveyor shaft assemblies (4).

7. The double-chain clamping and conveying device for a vacuum packaging machine according to claim 1, characterized in that: Two sets of double-chain clamping and conveying mechanisms, corresponding to the upper and lower film rolls, start and stop synchronously and move at the same speed to ensure that the clamping depth, tensile tension and conveying accuracy of the upper and lower films are consistent.

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