Automatic mechanical property pre-tightening device for upper film and lower film

Abstract

An upper film and lower film automatic mechanical performance pre-tightening device comprises a lower film roller and a crank-shaped tensioning roller, fixed rotating shafts at the same ends of the lower film roller and the tensioning roller penetrate through vertical film roller mounting plates respectively, a brake disc is fixed to the lower film roller fixed rotating shaft on the other side of each film roller mounting plate, and an eccentric block is fixed to one end of the tensioning roller on the same side of the brake disc. A brake arm is rotationally arranged on the film roller mounting plate on one side of the brake disc, an elastic structure arranged on the brake arm enables the brake surface of the brake arm to be tightly attached to the brake disc, the eccentric block is used for making contact with the outer end of the brake arm, and when the outermost end of the eccentric block makes vertical contact with the brake arm, the brake surface of the brake arm is separated from the brake disc. By means of the linkage structure, friction resistance of the lower film roller can be automatically adjusted, the lower film roller can be better matched with drawing and stretching of a lower film, it can be guaranteed that the lower film has enough tensioning force after being drawn out, the flatness of the lower film is effectively guaranteed, the lower film can be prevented from being further excessively stretched, and the lower film is better protected against being damaged by pulling.

Description

Technical Field

[0001] This utility model relates to the field of vacuum packaging machine technology, specifically to an automatic mechanical pre-tightening device for upper and lower film. Background Technology

[0002] Packaging machines are commonly used food packaging equipment, such as stretch film packaging machines. Current stretch film packaging machines have a tensioning roller at the feeding part, that is, on the side of the shaft where the lower stretch film is installed. The function of the tensioning roller is to keep the lower stretch film taut at all times, so that the lower stretch film can be flattened after being pulled out. The current tensioning roller mainly relies on its own weight to achieve tension, but it is not possible to adjust the rotation speed of the roller that holds the lower stretch film in real time, so the tension adjustment effect is poor. Summary of the Invention

[0003] In order to solve the above problems, the purpose of this utility model is to provide an automatic mechanical pre-tightening device for upper and lower membranes.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows: an automatic mechanical performance pre-tightening device for upper and lower film, comprising a lower film roller and a crank-shaped tension roller, a fixed rotating shaft at the same end of the lower film roller and the tension roller respectively passing through a vertical film roller mounting plate, a brake disc fixed on the lower film roller fixed rotating shaft on the other side of the film roller mounting plate, an eccentric block fixed at one end of the tension roller on the same side as the brake disc, a brake arm rotatably mounted on the film roller mounting plate on one side of the brake disc, and the elastic structure of the brake arm makes the brake surface of the brake arm closely adhere to the brake disc, the eccentric block is used to contact the outer end of the brake arm, and when the outermost end of the eccentric block is in perpendicular contact with the brake arm, the brake surface of the brake arm is separated from the brake disc.

[0005] Furthermore, the elastic structure is a compression spring, which is located on the side away from the eccentric block. One end of the compression spring contacts the brake arm, pushing the brake arm to make the brake arm fit tightly against the brake disc. The other end of the compression spring is fixed in the compression spring fixing block on the side of the film roller mounting plate.

[0006] Furthermore, the eccentric block has a quarter-elliptical structure, and the edge of the elliptical arc contacts the brake arm.

[0007] Furthermore, the brake arm and the spring fixing block are respectively provided with spring fixing holes corresponding to the ends of the springs.

[0008] Furthermore, the fixed shafts of the lower film roller and the tension roller are respectively fitted with bearing structures at the parts that pass through the film roller mounting plate, and each fixed shaft is rotatably supported within the bearing structure.

[0009] Furthermore, the crank-shaped tensioning roller includes a rotating roller and a swing arm. The rotating roller is rotatably mounted on the swing end of the swing arm, and the rotating roller is perpendicular to the swing arm and parallel to the lower film roller. The rotating end of the swing arm is perpendicularly and fixedly connected to the fixed rotating shaft.

[0010] With the above settings, under normal conditions, the elastic structure of the brake arm ensures that the brake surface of the brake arm is in close contact with the brake disc, i.e., the brake arm and the brake disc are in contact, creating a certain frictional resistance on the brake disc, which in turn creates resistance on the lower film roller. This creates a certain tension when the lower film is pulled out, keeping the lower film within a reasonable tension range. When the lower film is stretched too much, the tension roller is lifted to a certain extent. Since the tension roller has a crank-shaped structure, one end of its fixed rotating shaft, i.e., the eccentric block, rotates. At this time, when the outermost end of the eccentric block is in perpendicular contact with the brake arm, i.e., the maximum radius of the eccentric structure of the eccentric block is in perpendicular contact with the brake arm, the brake surface of the brake arm separates from the brake disc. At this time, the brake disc loses frictional resistance, which facilitates the rotation of the lower film roller, making the lower film pull out more smoothly, reducing the required pulling force and tension force, thereby effectively preventing the lower film from being stretched further.

[0011] This linkage structure enables automatic adjustment of the frictional resistance of the lower film roller, better coordinating with the stretching of the lower film. This ensures sufficient tension after stretching, effectively guaranteeing the flatness of the lower film, while preventing further overstretching and better protecting it from damage. (Applicants may add supplementary information.) Attached Figure Description

[0012] The present invention will now be further described with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic diagram of the main structure of this utility model;

[0014] Figure 2 This is a frontal perspective view of the present invention.

[0015] Figure 3 This is a three-dimensional structural diagram of the back of the present invention;

[0016] Figure 4 This is a physical reference drawing of the present invention. Detailed Implementation

[0017] like Figure 1-3As shown, an automatic mechanical pre-tensioning device for upper and lower film includes a lower film roller 1 and a crank-shaped tension roller 2. The fixed rotating shafts at the same end of the lower film roller 1 and the tension roller 2 respectively pass through a vertical film roller mounting plate 3. A brake disc 4 is fixed to the fixed rotating shaft of the lower film roller 1 on the other side of the film roller mounting plate 3. An eccentric block 5 is fixed to one end of the tension roller 2 on the same side as the brake disc 4. A brake arm 6 is rotatably mounted on the film roller mounting plate 3 on one side of the brake disc 4. The elastic structure of the brake arm 6 allows the brake surface of the brake arm 6 to be in close contact with the brake disc 4, and the contact part of the brake arm 6 can be recessed inward and provided with a friction pad, such as a rubber friction pad, that is in contact with the brake disc. The eccentric block 5 is used to contact the outer end of the brake arm 6. Specifically, the eccentric block 5 is a quarter-elliptical structure, and the edge of the elliptical arc contacts the brake arm 6. When the outermost end of the eccentric block 5 is in perpendicular contact with the brake arm 6, the brake surface of the brake arm 6 is separated from the brake disc 4.

[0018] The elastic structure is a compression spring 7, which is located on the side away from the eccentric block 5. One end of the compression spring 7 contacts the brake arm 6, pushing the brake arm 6 to make it press tightly against the brake disc 4. The other end of the compression spring 7 is fixed in the compression spring fixing block 8 on the side of the film roller mounting plate 3. The brake arm 6 and the compression spring fixing block 8 are respectively provided with compression spring fixing holes 9 corresponding to the ends of the compression spring 7. The fixed rotating shafts of the lower film roller 1 and the tension roller 2 are respectively fitted with bearing structures at the parts that pass through the film roller mounting plate 3. Each fixed rotating shaft is rotatably supported in the bearing structure.

[0019] Specifically: The crank-shaped tensioning roller 2 includes a rotating roller 201 and a swing arm 202. The rotating roller 201 is rotatably disposed at the swing end of the swing arm 202, and the rotating roller 201 is perpendicular to the swing arm 202 and parallel to the lower film roller 1. The rotating end of the swing arm 202 is vertically and fixedly connected to the fixed rotating shaft.

[0020] The working principle of this utility model is as follows: This utility model is installed in the first position of the stretch packaging machine, that is, the position where the stretch film is stored. The rolled stretch film is placed on the lower film roller 1. The lower film passes under the tension roller 2 (i.e., the rotating roller 201). Under normal conditions, the elastic structure of the brake arm 6 makes the brake surface of the brake arm 6 closely adhere to the brake disc 4, that is, the brake arm 6 contacts the brake disc 4, so that the brake disc 4 forms a certain frictional resistance, thereby creating resistance on the lower film roller 1. In this way, a certain tension is formed when the lower film is pulled out, keeping the lower film within a reasonable tension range. When the lower film is over-tensioned, the tension roller 2 is lifted to a certain extent. Since the tension roller 2 has a crank-shaped structure, one end of its fixed rotating shaft, i.e., the eccentric block 5, is used. When the eccentric block 5 rotates, its outermost end comes into perpendicular contact with the brake arm 6, meaning the maximum radius of the eccentric structure of the eccentric block 5 comes into perpendicular contact with the brake arm 6. This causes the brake surface of the brake arm 6 to separate from the brake disc 4. At this point, the brake disc 4 loses its frictional resistance, which facilitates the rotation of the lower film roller 1, making the lower film pull out more smoothly. The required pulling force and tension force are reduced, which effectively prevents the lower film from being overstretched further. This linkage structure automatically adjusts the frictional resistance of the lower film roller 1, better coordinating with the pulling out and stretching of the lower film. It ensures that the lower film has sufficient tension force after being pulled out, effectively ensuring the flatness of the lower film, and also prevents the lower film from being overstretched further, thus better protecting the lower film from being damaged.

[0021] The above description is merely an illustrative embodiment of this utility model and is not intended to limit the scope of this utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of this utility model should fall within the protection scope of this utility model.

Claims

1. An automatic mechanical pre-tensioning device for upper and lower film, comprising a lower film roller (1) and a crank-shaped tension roller (2), wherein a fixed rotating shaft at the same end of the lower film roller (1) and the tension roller (2) respectively passes through a vertical film roller mounting plate (3), characterized in that: A brake disc (4) is fixed on the shaft of the lower film roller (1) on the other side of the film roller mounting plate (3). An eccentric block (5) is fixed on one end of the tension roller (2) on the same side as the brake disc (4). A brake arm (6) is rotatably mounted on the film roller mounting plate (3) on one side of the brake disc (4). The elastic structure of the brake arm (6) makes the brake surface of the brake arm (6) fit tightly against the brake disc (4). The eccentric block (5) is used to contact the outer end of the brake arm (6). When the outermost end of the eccentric block (5) is in perpendicular contact with the brake arm (6), the brake surface of the brake arm (6) is separated from the brake disc (4).

2. The automatic mechanical property pre-tightening device for upper and lower films as described in claim 1, characterized in that: The elastic structure is a compression spring (7). The compression spring (7) is located on the side away from the eccentric block (5). One end of the compression spring (7) contacts the brake arm (6) and pushes the brake arm (6) to make the brake arm (6) fit tightly against the brake disc (4). The other end of the compression spring (7) is fixed in the compression spring fixing block (8) on the side of the film roller mounting plate (3).

3. The automatic mechanical property pre-tightening device for upper and lower films as described in claim 1, characterized in that: The eccentric block (5) has a quarter-elliptical structure, and the edge of the elliptical arc contacts the brake arm (6).

4. The automatic mechanical property pre-tightening device for upper and lower films as described in claim 2, characterized in that: The brake arm (6) and the spring fixing block (8) are respectively provided with spring fixing holes (9) corresponding to the end of the spring (7).

5. The automatic mechanical property pre-tightening device for upper and lower films as described in claim 1, characterized in that: The fixed rotating shafts of the lower film roller (1) and the tension roller (2) are respectively fitted with bearing structures at the parts that pass through the film roller mounting plate (3), and each fixed rotating shaft is rotatably supported in the bearing structure.

6. The automatic mechanical property pre-tightening device for upper and lower films as described in claim 1, characterized in that: The crank-shaped tension roller (2) includes a rotating roller (201) and a swing arm (202). The rotating roller (201) is rotatably mounted on the swing end of the swing arm (202), and the rotating roller (201) is perpendicular to the swing arm (202) and parallel to the lower film roller (1). The rotating end of the swing arm (202) is vertically and fixedly connected to the fixed rotating shaft.

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