Plastic bag notch forming and conveying device

Abstract

The invention discloses a plastic bag notch forming and conveying device which comprises a linear driving device, a rotating rope sleeve and a pressing roller, the output end of the linear driving device is connected with a forming cutter, the rotating rope sleeve is arranged on the downstream of the forming cutter and located above a plastic bag, and the rotating rope sleeve is connected with a driving source providing rotating torque. The pressing roller is arranged at the downstream position of the line body, the pressing roller is vertically arranged below the rotating rope sleeve in a sliding mode through a synchronous connecting rod, and the pressing roller is axially and rotationally arranged around the synchronous connecting rod. The pressing roller slides close to and away from the rotary rope sleeve in a reciprocating mode along with the forming cutter to form spaced contact and disconnection with the pressing roller, so that an intermittent conveying mechanism matched with the notch forming procedure in a crossed mode is achieved, the complex mode of depending on multi-motor electronic synchronization is avoided, and through pure mechanical contact and separation actions, the forming efficiency is improved. And intermittent material output work is completed, so that the problem that the plastic bag is torn due to asynchronous driving is solved.

Description

Technical Field

[0001] This invention relates to the field of conveying device technology, and specifically to a plastic bag notch forming conveying device. Background Technology

[0002] As a daily consumer product, the precise and efficient forming of handle notches on the bag body is a key step in the production and processing of plastic bags. The quality of the technical solution has a decisive impact on the yield and production cost of the final product.

[0003] In actual production, the material conveying methods on automated plastic bag production lines are mainly divided into two types: intermittent and continuous. While continuous conveying is more efficient, it places extremely stringent requirements on the synchronous control of the forming cutter and the conveying device, resulting in complex and costly equipment. Therefore, intermittent conveying devices are more commonly used in stations such as plastic bag notch forming.

[0004] Currently, the most common intermittent plastic bag conveying devices on the market are based on a start-stop control scheme using standard electrical components, combined with a friction conveying technology using rotating ropes. They primarily rely on a servo motor as a power source, intermittently starting and stopping the rotation of the ropes to intermittently output the plastic bags clamped between the upper and lower ropes.

[0005] However, this method of using a servo motor to control the intermittent movement of the rope loop causes the rope loop to accelerate and stop frequently, thereby directly transferring the inertial load and positioning error to the rotating rope loop. This can easily reduce the stability of the rotating rope loop in long-term production, thus limiting the application effect of this technology. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: A plastic bag notch forming conveyor includes a linear drive device, the output end of which is connected to a forming cutter for intermittently notching and punching plastic bags on the line. A rotating rope loop is disposed downstream of the forming cutter and above the plastic bag, and the rotating rope loop is connected to a drive source that provides rotational torque to drive the rotating rope loop to rotate continuously. A pressing roller is positioned downstream of the line body to hold a pre-formed plastic bag. The pressing roller is vertically slidably positioned below the rotating rope loop via a synchronous connecting rod, and the pressing roller is axially rotatable around the synchronous connecting rod. When the pressing roller moves upward and contacts the rotating rope sleeve, the rotating rope sleeve drives the pressing roller to rotate through friction, so as to output the molded plastic bag held by the rotating rope sleeve and the pressing roller downstream.

[0007] In a preferred embodiment of the present invention, the pressing roller is connected to the forming cutter via a synchronous connecting rod to perform synchronous and unidirectional movement.

[0008] As a preferred embodiment of the present invention, an air supply assembly is provided on the production line, and the air outlet of the air supply assembly is located above the pressing roller. The air outlet outputs air pressure to the pressing roller to continuously press the plastic bag onto the pressing roller.

[0009] As a preferred embodiment of the present invention, a carrier for receiving the formed plastic bag is provided at the upstream position of the pressing roller. The carrier is vertically slidably disposed on the line body, and the carrier is fixedly connected to the pressing roller for synchronous lifting and lowering.

[0010] As a preferred embodiment of the present invention, the surface of the carrier is provided with a wind pressure input port; The air supply assembly includes a bidirectional air pump mounted on the line body. The air pump's air inlet is connected to the air pressure input port via an air pipe to negatively adsorb the upstream molded plastic bag onto the carrier surface. The air pump's air outlet is mounted above the pressure roller via a mounting housing to press the downstream plastic bag onto the pressure roller.

[0011] As a preferred embodiment of the present invention, the mounting housing includes a housing covering the outside of the rotating rope loop and a bellows disposed on the top surface of the housing. The bellows is connected to the air outlet of the bidirectional air pump through an air pipe. The bellows is provided with a wind pressure output port, and the wind pressure output port is provided with a closing structure for selectively opening and closing the wind pressure output port. The closed structure opens the air pressure output port when the pressure roller falls; The closed structure seals the air pressure output port when the pressure roller rises.

[0012] As a preferred embodiment of the present invention, the closed structure includes a sealing plate disposed inside the wind box. The sealing plate is slidably disposed on one side of the wind pressure output port via a sliding plate. A driven gear is connected to the sliding plate by toothed meshing. The driven gear is rotatably disposed inside the wind box via a rotating shaft. A drive gear is disposed at the end of the rotating shaft. The drive gear is meshed with a toothed plate. The toothed plate extends downward through the wind box. The toothed plate is fixedly connected to the pressure roller / the carrier via the synchronous connecting rod for synchronous lifting and lowering.

[0013] As a preferred embodiment of the present invention, a gap is provided between the rotating rope and its downstream winding roller to form a bag storage area, which is used to temporarily store plastic bags without pretension that are intermittently output by the rotating rope and the pressure roller. A tensioning structure is provided in the bag storage area. The tensioning structure is used to tension the unpre-tightened plastic bags in the bag storage area so as to continuously transport the intermittently output plastic bags downstream.

[0014] In a preferred embodiment of the present invention, the tensioning structure includes a baffle and a flexible sheet sequentially disposed downstream of the rotating rope loop. The bottom of the flexible sheet is located below the take-up roller to form a tensioning slope. The baffle and the flexible sheet are spaced apart to form a surplus molded plastic bag in front of the baffle. The surplus molded plastic bag passes through the bottom of the flexible sheet and is mounted on the take-up roller for downstream output. The bottom of the flexible sheet can bend upward or move to adaptively compress the surplus molded plastic bag at different drop heights.

[0015] Compared with the prior art, the present invention has the following advantages: This invention utilizes the reciprocating sliding motion of the pressure roller as it approaches and moves away from the rotating rope sleeve following the forming cutter, creating intermittent contact and disconnection with the pressure roller. This achieves an intermittent conveying mechanism that is cross-coordinated with the cutting and forming process, avoiding the complex mode of intermittent operation relying on motor pulses. Through purely mechanical contact and separation actions, intermittent material output is completed, thus avoiding problems such as overall structural instability and poor synchronization caused by frequent start and stop of the rotating rope sleeve. Attached Figure Description

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the forming cutter and rotating rope loop of the present invention; Figure 3 This is a side view of the present invention; Figure 4 This is a schematic diagram of the structure of the molded plastic bag output from the present invention; Figure 5 This is a schematic diagram of the rotating rope loop of the present invention; Figure 6 This is a schematic diagram of the air supply assembly of the present invention; Figure 7 This is a schematic diagram of the closed structure of the present invention; The labels in the diagram represent the following: 1. Linear drive unit; 2. Forming cutter; 3. Rotating rope loop; 4. Pressure roller; 5. Synchronous connecting rod; 6. Air pressure output port; 7. Carrier; 8. Air pressure input port; 9. Bidirectional air pump; 10. Housing; 11. Air box; 12. Sealing plate; 13. Slide plate; 14. Driven gear; 15. Rotating shaft; 16. Drive gear; 17. Toothed plate; 18. Bag storage area; 19. Tensioning structure; 20. Baffle; 21. Flexible sheet; 22. Take-up roller. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0019] like Figures 1 to 5 As shown, this invention provides a plastic bag notch forming conveyor device, including a linear drive device 1, preferably a cylinder or electric push rod, whose output end is connected to a forming cutter 2 for intermittently notching plastic bags on the conveyor line. The linear drive device 1 receives pulse signals from a control system (such as a PLC) and performs periodic extension and retraction movements, thereby driving the forming cutter 2 to intermittently notch-cut the continuously conveyed plastic film conveyor line below. The conveyor line is a horizontally arranged conveyor belt with an anti-slip coating on its surface to ensure stable conveying of plastic bags. During the notching process, a receiving mold that cooperates with the forming cutter 2 is set below the conveyor line to ensure a smooth cut without burrs.

[0020] Downstream of the forming cutter 2, a rotating rope sleeve 3 is mounted via an assembly and positioned above the plastic bag. The rotating rope sleeve 3 is an annular band made of a flexible material (such as rubber or silicone) with a rough outer surface to increase friction. The rotating rope sleeve 3 is connected to a drive source that provides rotational torque to drive it to rotate continuously. The rotating rope sleeve 3 is prior art, as... Figure 1 or Figure 5 As shown, the rotating rope sleeve 3 is driven to rotate by two rotating rollers. The rotating rope sleeve 3 is fixedly connected to the rotating rollers or frictionally connected to the rotating rollers, so that when the rotating rollers rotate, they drive the rotating rope sleeve 3 to rotate synchronously and continuously, rather than intermittently.

[0021] Downstream of the plastic film production line, a pressure roller 4 is installed to hold the pre-cut plastic bags. The pressure roller 4 is vertically slidable below the rotating rope sleeve 3 via a synchronous connecting rod 5, and is axially rotatable about the synchronous connecting rod 5. The pressure roller 4 is rotatably mounted on the synchronous connecting rod 5. This synchronous connecting rod 5 is vertically slidable on the frame, allowing the pressure roller 4 to rotate freely about the axis of the synchronous connecting rod 5 and also to move vertically up and down with the synchronous connecting rod 5 as a whole.

[0022] When the pressure roller 4 moves upward and contacts the rotating rope sleeve 3, the rotating rope sleeve 3 drives the pressure roller 4 to rotate through friction so as to output the molded plastic bag held by the rotating rope sleeve 3 and the pressure roller 4 downstream.

[0023] The pressure roller 4 is connected to the forming cutter 2 via a synchronous connecting rod 5 to move synchronously in the same direction. This ensures that when the forming cutter 2 moves downwards and makes a cut, it drives the pressure roller 4 to move downwards away from the rotating rope sleeve 3, thus guaranteeing the stable operation of the forming cutter 2. When the forming cutter 2 completes its cutting action and moves upwards, it drives the pressure roller 4 to move synchronously and contact the rotating rope sleeve 3.

[0024] Specifically, the core working process is as follows: When the production line is in operation, the forming cutter 2, driven by the linear drive device 1, slides back and forth to cut the plastic bags on the line. At the same time, the pressure roller 4 moves downward under vertical drive, so that the pressure roller 4 moves away from the rotating rope sleeve 3, thereby not outputting plastic bags and maintaining the stable cutting operation of the forming cutter 2.

[0025] When the forming cutter 2 finishes cutting and slides upward, the pressure roller 4 moves upward and comes into contact with the continuously rotating rope sleeve 3 above. Under the action of friction, the rotating rope sleeve 3 drives the pressure roller 4 to rotate synchronously. At this time, the formed plastic bag, which is clamped between the rotating rope sleeve 3 and the pressure roller 4, is quickly and accurately "exploded" downstream under the combined action of the clamping force of the rotating rope sleeve 3 and the pressure roller 4 and the friction force of the rotating rope sleeve 3 on the plastic bag, completing one intermittent conveying cycle. After the conveying is completed, the pressure roller 4 moves downward and disengages from the rotating rope sleeve 3, the conveying stops, and the forming cutter 2 can then perform the next cutting. This forms a mechanical cross-cooperation.

[0026] In specific settings, such as Figure 1 , Figure 2 and Figure 5 As shown, the covering lengths of both the rotating rope loop 3 and the pressure roller 4 are greater than the width of the plastic bag. The portion of the rope loop 3 covering the plastic bag serves two purposes: firstly, to clamp the plastic bag, and secondly, to squeeze and rotate the plastic bag through the pressure roller 4, driving its output. The portions of the rotating rope loop 3 and the pressure roller that do not contact the plastic bag are designed so that they can come into contact with each other, allowing the rotating rope loop 3 to contact the pressure roller 4 and drive it to rotate.

[0027] In this device, the pressure roller 4 is driven to rotate by the rotating rope sleeve 3. Specifically, the rotating rope sleeve 3 can be made of a highly wear-resistant synthetic rope sleeve or a flexible material with a certain friction, and the pressure roller 4 can be a polyurethane-coated pressure roller or a rubber pressure roller assembly.

[0028] The rotating rope loop 3 can be made of a flexible material with friction particles on its outer surface, or a shaft rope with internally filled rough edges and externally wound with a rigid material (the rough edges extend from the winding intervals to create friction). They have high surface friction and, when used with the soft rubber roller, can effectively drive the pressure roller 4 to rotate and apply friction to the plastic bag.

[0029] The pressure roller 4 can be made of a metal shaft sleeve connected to a rubber roller. The friction and local deformation capacity of the rubber material ensure rapid and reliable rotation at the moment of contact, preventing slippage. The surface friction of the pressure roller 4 can be adaptively selected according to actual operating conditions to ensure axial rotation when in contact with the rotating rope sleeve 3, and that it does not carry the plastic bag out when rotating due to inertia after disconnection from the rotating rope sleeve 3, i.e., the plastic bag "slips" on the pressure roller 4. Specifically, for example, the pressure roller 4 can be equipped with a side friction section and a central smooth section. The side friction section has a certain friction force for contact with the rotating rope sleeve 3 and for being driven to rotate, while the central smooth section has lower friction or is a smooth section, thus preventing the plastic bag from being carried out of the conveyor during inertial rotation while being driven.

[0030] In this device, the plastic bag after cutting and forming is "sprayed" downstream by the combined action of the rotating rope sleeve 3 and the pressure roller 4 clamping each other and rotating together. The contact between the rotating rope sleeve 3 and the plastic bag is essential.

[0031] like Figure 6 As shown, the rotating rope loop 3 consists of multiple ropes spaced apart. When the pressure roller 4 rises and contacts it, the rope loop 3 contacts the plastic bag at multiple points on the pressure roller 4. Since the contact area of ​​a single rotating rope loop 3 is small, the pressure on the plastic bag at a single point is relatively large. Thus, under the action of rotating together with the pressure roller 4, plus the friction between the rotating rope loop 3 and the plastic bag, the output action of the plastic bag is completed.

[0032] Among them, such as Figure 2As shown, the pressure roller 4 is mechanically connected to the forming cutter 2 via a synchronous connecting rod 5, achieving synchronous and unidirectional movement. The synchronous connecting rod 5 employs a rigid linkage mechanism to connect the forming cutter 2 and the pressure roller 4. When the linear drive device 1 drives the forming cutter 2 to press down for punching, the synchronous connecting rod 5 simultaneously drives the pressure roller 4 to move downward, releasing its contact with the rotating rope sleeve 3; when the forming cutter 2 moves upward to reset, the pressure roller 4 synchronously moves upward and contacts the rotating rope sleeve 3, entering the clamping and conveying state. This synchronous movement is achieved through mechanical linkage, ensuring the time coordination of punching and conveying actions. Example 2:

[0033] Based on Example 1, to improve the stability of plastic bag output and ensure that the plastic bag remains stably attached to the pressure roller 4 during its ascent or descent, this embodiment adds an air supply component to the production line to enhance the stability of the plastic bag on the pressure roller 4. Figure 2 , Figure 5 and Figure 7 As shown. Specifically, the air supply assembly includes a small fan or air pump, mounted on a fixed bracket at the bottom of the pressure roller 4, as shown. Figure 2 and Figure 5 As shown, its air outlet is located directly above the pressure roller 4, as... Figure 6 and Figure 7 As shown, the air outlet adopts a flat nozzle design to provide uniform air pressure. The air pressure direction can be vertically downward towards the surface of the pressure roller 4, or inclined from upstream to downstream of the plastic bag, so that the air pressure from the outlet passes slightly over the plastic bag on the pressure roller 4 from upstream to downstream, ensuring that the plastic bag remains in contact with the pressure roller 4 during transportation and avoiding displacement caused by air buoyancy or static electricity. The air volume of the air supply component can be adjusted by a frequency converter to adapt to plastic bags of different materials and thicknesses. In addition, the angle of the air outlet can be finely adjusted to ensure that the air pressure covers the entire surface of the pressure roller 4, improving the pressing effect.

[0034] Additionally, a carrier 7 is added upstream of the pressure roller 4, such as... Figure 5 and Figure 6 As shown, the system is designed to support freshly punched plastic bags, ensuring stable and higher transport of the bags between the pressure roller 4 and the cutting station. A single-piece carrier plate is installed on the line to support the plastic bags during punching by the forming cutter 2. A slot is cut into the carrier plate for sliding the carrier seat 7. The carrier seat 7 is a planar structure with a low-friction material (such as a PTFE coating) to facilitate the sliding of the plastic bags. The carrier seat 7 and the pressure roller 4 are synchronously raised and lowered via a fixed connection, as shown in the figure. Both the carrier seat 7 and the pressure roller 4 are connected to a synchronous support to ensure that their relative positions remain unchanged during movement. Figure 6As shown, the lifting and lowering motion of the carrier 7 is synchronized with the movement of the pressure roller 4. When the pressure roller 4 moves upward to clamp the plastic bag, the carrier 7 moves upward simultaneously to receive the new molded plastic bag; when the pressure roller 4 moves downward to release, the carrier 7 moves downward simultaneously to complete the transition of the plastic bag, making the synchronization effect of the plastic bag movement better.

[0035] Furthermore, to improve the stability of the plastic bag during its vertical movement and optimize the structural configuration of the feeding assembly, a wind pressure input port 8 is provided on the surface of the carrier 7, such as... Figure 6 As shown, they are arranged in strips or grids. Figure 6 The middle section is arranged in a strip shape to form a negative pressure adsorption area. The air pump 9 of the air supply assembly is connected to the air pressure input port 8 of the carrier 7 and the air outlet above the pressure roller 4 through the split air pipe.

[0036] In practice, the air pump is a bidirectional air pump 9, capable of both positive pressure output and negative pressure adsorption. The air pump's inlet is connected to the air pressure input port 8 of the carrier 7 via a flexible air tube, creating a negative pressure adsorption force that firmly adheres the upstream molded plastic bag to the surface of the carrier 7, preventing slippage or displacement. The air pump's outlet is fixed above the pressure roller 4 via a mounting housing, outputting positive pressure to press the downstream plastic bag against the pressure roller 4. The air pump's operating parameters (such as airflow and pressure) are precisely adjusted by a PLC controller to balance the adsorption and pressing forces required.

[0037] The mounting housing comprises two parts: a housing 10 and a bellows 11. For example... Figures 1 to 3 , Figures 5 to 7 As shown, the housing 10 is a metal or plastic shell covering the rotating rope sleeve 3, used to protect the rotating rope sleeve 3 and guide airflow. The bellows 11 is fixed to the top surface of the housing 10, has a hollow internal structure, and is connected to the air outlet of the air pump through an air pipe, as shown. Figure 6 As shown. A pressure output port 6 is provided on the bottom surface of the bellows 11. A closed structure is provided on the pressure output port 6 for selectively opening and closing the pressure output, such as... Figure 7 As shown. When the pressure roller 4 falls, the plastic bag, being relatively light, floats up and detaches from the pressure roller 4. At this time, the closed structure drives the baffle to open the air pressure output port 6, allowing air pressure to act on the plastic bag on the pressure roller 4, pressing it against the pressure roller 4. When the pressure roller 4 rises and contacts the rotating rope sleeve 3, the pressure roller 4 will move the plastic bag upwards synchronously. The resistance of the air medium will press the plastic bag against the pressure roller 4. Therefore, at this time, the closed structure can close the air pressure output port 6, pausing the air pressure output to save energy and avoid airflow interference with the clamping action.

[0038] Furthermore, such as Figure 7As shown, the closed structure specifically includes a sealing plate 12, which is disposed inside the bellows 11 and slidably disposed on one side of the air pressure output port 6 via a sliding plate 13. The sliding plate 13 is connected to a driven gear 14 via toothed engagement. The driven gear 14 is disposed inside the bellows 11 via a rotating shaft 15. The driven gear 14 is fixedly connected to the rotating shaft 15 so that the driven gear 14 rotates when the rotating shaft 15 rotates. A drive gear 16 is connected to the end of the rotating shaft 15. The drive gear 16 meshes with a toothed plate 17, which extends downward through the bellows 11 and is fixedly connected to the synchronous connecting rod 5 or the carrier 7 via a fixing clamp.

[0039] Combination Figures 6 to 7 As shown, when the pressure roller 4 or the carrier 7 rises or falls, the toothed plate 17 moves synchronously with the synchronous connecting rod 5, driving the slide plate 13 to move through gear transmission, thereby realizing the opening and closing of the sealing plate 12. For example, when the forming cutter 2 performs a downward cutting action, it drives the pressure roller 4 to fall synchronously while rotating the rope loop 3. At this time, the toothed plate 17 moves downward synchronously, driving the gear 16 to rotate and causing the sealing plate 12 to slide open, opening the air pressure output port 6 to output air pressure to the falling pressure roller 4, so that the plastic bag adheres to the pressure roller 4. When the forming cutter 2 completes the cutting action and rises, it drives the pressure roller 4 to rise synchronously, the toothed plate 17 moves upward, driving the gear 16 to rotate and causing the sealing plate 12 to close the air pressure output port 6. This achieves the advantages of no additional power supply, simple structure, good synchronization, and high reliability. Example 3:

[0040] In Example 2, the formed plastic bags are output intermittently by the rotating rope loop 3 and the pressure roller 4. Therefore, based on Example 2, as... Figure 3 and Figure 4 As shown, in this embodiment, a bag storage area 18 is provided downstream of the plastic bag output by the rotating rope loop 3. A tensioning structure 19 is provided in the bag storage area 18 to tension the intermittently output plastic bags with a certain initial velocity so as to facilitate the continuous output of the subsequent continuous output roller.

[0041] Specifically, a bag storage area 18 is provided between the rotating rope sleeve 3 and the downstream take-up roller 22 to temporarily store intermittently output plastic bags without pretension. The bag storage area 18 is an open space, and its length is designed according to the production cycle. A tensioning structure 19 is provided within the bag storage area 18 to tension the plastic bags without pretension, ensuring their continuous downstream transport. The tensioning structure 19 includes a baffle 20 and a flexible sheet 21. The baffle 20 is a flexible metal sheet suspended downstream of the rotating rope sleeve 3, with its front facing downstream of the plastic bags output by the rotating rope sleeve 3. It blocks the forward movement of the plastic bags output from the rotating rope sleeve 3, thereby forming a surplus plastic bag in front of the baffle 20. This surplus plastic bag separates the plastic bags intermittently output by the rotating rope sleeve 3 upstream from the plastic bags continuously wound by the downstream take-up roller 22, allowing them to operate independently without interference. Specifically, the intermittently output plastic bags from the upstream form a surplus plastic bag in front of the baffle 20. After the surplus plastic bag hits the baffle 20, it falls down. During the downward process, it is wound up by the continuously winding roller 22 at the rear, so that the surplus plastic bag is continuously wound up by the winding roller 22 before it falls to the bottom. This ensures a stable connection between the intermittently output plastic bags from the upstream and the continuously winding roller 22 at the downstream.

[0042] The flexible sheet 21, such as a silicone sheet or a thin metal sheet, is positioned below the take-up roller 22, forming an inclined tension slope. This allows the plastic bag, passing through the bottom of the flexible sheet 21, to be mounted on the downstream, higher take-up roller 22, forming an inclined plastic bag. The tension slope causes the formed plastic bag to rise from bottom to top, achieving tension. The gap between the baffle 20 and the flexible sheet 21 allows a pre-tensioned area to form at the bottom of both the baffle 20 and the flexible sheet 21. This pre-tensioned area prepares for the subsequent tensioning stage. Specifically, if the distance between the bottom of the baffle 20 and the bottom of the flexible sheet 21 is too small, the plastic bag will not pass through (not contact) the bottom of the baffle 20 during continuous output, but will directly contact the bottom of the flexible sheet 21 and be output. Since the baffle 20 at the front will form excess plastic bag, and the excess plastic bag cannot be instantly output by the subsequent continuous output take-up roller 22, part of the excess plastic bag will fall due to gravity when the bag is output from the front. If the distance between the bottom of the baffle 20 and the bottom of the flexible sheet 21 is too small, the plastic bag will directly contact the bottom of the flexible sheet 21 and be output. At this time, when the excess plastic bag falls, it will form a gap at the bottom of the flexible sheet 21, that is, it will not directly and continuously contact the flexible sheet 21, but will form a gap at the bottom of the flexible sheet 21. This gap will cause jamming and discontinuity in the take-up roller 22 during the take-up state, which will easily cause the bag to break.

[0043] Therefore, in order to avoid this situation, the tensioning structure of this embodiment makes the bottom of the baffle 20 higher than the bottom of the flexible sheet 21 and there is a gap between them. On the other hand, it makes the bottom of the flexible sheet 21 able to bend upward or move to adapt to the stacking of plastic bags at different placement heights.

[0044] Its specific working principle is as follows: The gap between the baffle 20 and the flexible sheet 21 forms a pre-tensioning zone, which can tension a portion of the plastic bag located there. The tensioning and winding zone formed between the flexible sheet 21 and the winding roller 22 directly extracts the plastic bag from the pre-tensioning zone for tensioning and winding. When the plastic bag hits the baffle 20, forming a surplus plastic bag and falling, it will at most form a gap at the bottom of the baffle 20, but will not form a gap at the bottom of the flexible sheet 21, thus enabling the winding roller 22 to continuously and stably wind up the bag. Furthermore, the bending and movement of the bottom of the flexible sheet 21 is to adapt to the instability of the plastic bag during winding. When the plastic bag appears unstable at the bottom of the flexible sheet 21, i.e., fluctuating in height, the bottom end of the flexible sheet 21 can adapt to this height change by bending or moving upwards. More importantly, it can press down on the plastic bag through the weight of the curled bottom part, thereby continuously maintaining its tension. That is, the bottom part of the flexible sheet 21 is unrestrained and in a free state, and whether it curls up depends on the position of the plastic bag on the left. That is, when the position of the plastic bag at the bottom of the flexible sheet 21 is relatively high at a certain point in time, the bottom of the flexible sheet 21 will bend upward to adapt to the height due to the higher position of the bag on the left and the high-position winding of the right take-up roller 22. When the position of the plastic bag at the bottom of the flexible sheet 21 is relatively low at a certain point in time, the flexible sheet 21 will continuously descend to find support for the plastic bag. According to the actual application of the device in the workshop, in most cases, the bottom of the flexible sheet 21 is continuously kept in an upward curled state due to the action of the continuously outputting take-up roller 22 on the right.

[0045] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A plastic bag notch forming and conveying device, characterized in that, include: A linear drive device (1) is connected to a forming cutter (2) at its output end for intermittently punching and forming plastic bags on the line; A rotating rope loop (3) is disposed downstream of the forming cutter (2) and above the plastic bag. The rotating rope loop (3) is connected to a drive source that provides rotational torque to drive the rotating rope loop (3) to rotate continuously. A pressing roller (4) is positioned downstream of the line body to carry a pre-formed plastic bag. The pressing roller (4) is vertically slidably positioned below the rotating rope loop (3) via a synchronous connecting rod (5), and the pressing roller (4) is axially rotated around the synchronous connecting rod (5). When the pressing roller (4) moves upward and contacts the rotating rope sleeve (3), the rotating rope sleeve (3) drives the pressing roller (4) to rotate through friction so as to output the molded plastic bag held by the rotating rope sleeve (3) and the pressing roller (4) downstream.

2. The plastic bag notch forming and conveying device according to claim 1, characterized in that: The pressing roller (4) is connected to the forming cutter (2) via a synchronous connecting rod (5) to move synchronously in the same direction.

3. The plastic bag notch forming and conveying device according to claim 2, characterized in that: An air supply assembly is provided on the production line. The air outlet of the air supply assembly is located above the pressing roller (4). The air outlet outputs air pressure to the pressing roller (4) to continuously press the plastic bag onto the pressing roller (4).

4. The plastic bag notch forming and conveying device according to claim 3, characterized in that: An upstream position of the pressing roller (4) is provided with a carrier (7) for receiving the formed plastic bag. The carrier (7) is vertically slidably disposed on the line body, and the carrier (7) is fixedly connected to the pressing roller (4) for synchronous lifting and lowering.

5. The plastic bag notch forming and conveying device according to claim 4, characterized in that: The surface of the carrier (7) is provided with a wind pressure input port (8); The air supply assembly includes a bidirectional air pump (9) mounted on the line body. The air inlet of the air pump is connected to the air pressure input port (8) through an air pipe to adsorb the upstream molded plastic bag under negative pressure on the surface of the carrier (7). The air outlet of the air pump is mounted above the pressing roller (4) through a mounting housing to press the downstream plastic bag onto the pressing roller (4).

6. The plastic bag notch forming and conveying device according to claim 5, characterized in that: The mounting housing includes a housing (10) covering the outside of the rotating rope sleeve (3) and a bellows (11) disposed on the top surface of the housing (10). The bellows (11) is connected to the air outlet of the bidirectional air pump (9) through an air pipe. The bellows (11) is provided with a wind pressure output port (6). The wind pressure output port (6) is provided with a closed structure for selectively opening and closing the wind pressure output port (6). The closed structure opens the air pressure output port (6) when the pressure roller (4) falls. The closed structure closes the air pressure output port (6) when the pressure roller (4) rises.

7. A plastic bag notch forming and conveying device according to claim 6, characterized in that: The closed structure includes a sealing plate (12) disposed inside the air box (11). The sealing plate (12) is slidably disposed on one side of the air pressure output port (6) via a sliding plate (13). A driven gear (14) is connected to the sliding plate (13) by tooth meshing. The driven gear (14) is rotatably disposed inside the air box (11) via a rotating shaft (15). A drive gear (16) is disposed at the end of the rotating shaft (15). A toothed plate (17) is meshed with the drive gear (16). The toothed plate (17) extends downward through the air box (11). The toothed plate (17) is fixedly connected to the pressure roller (4) / the carrier (7) via the synchronous connecting rod (5) for synchronous lifting.

8. The plastic bag notch forming and conveying device according to claim 7, characterized in that: A gap is provided between the rotating rope sleeve (3) and its downstream winding roller (22) to form a bag storage area (18), which is used to temporarily store plastic bags without pretension that are intermittently output by the rotating rope sleeve (3) and the pressure roller (4); The storage area (18) is provided with a tensioning structure (19), which is used to tension the unpre-tightened plastic bags in the storage area (18) so as to continuously transport the intermittently output plastic bags downstream.

9. A plastic bag notch forming and conveying device according to claim 8, characterized in that: The tensioning structure (19) includes a baffle (20) and a flexible sheet (21) arranged sequentially downstream of the rotating rope (3). The bottom of the flexible sheet (21) is located below the winding roller (22) to form a tensioning slope. The baffle (20) and the flexible sheet (21) are spaced apart to form a surplus plastic bag in front of the baffle (20). The surplus plastic bag passes through the bottom of the flexible sheet (21) and is mounted on the winding roller (22) to be output downstream. The bottom of the flexible sheet (21) can be bent upward or moved to adaptively compress the surplus plastic bag at different drop heights.

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