TPU inflatable product welding machine with precise positioning function and welding method thereof

Abstract

The invention discloses a TPU inflatable product welding machine with a precise positioning function and a welding method of the TPU inflatable product welding machine. The TPU inflatable product welding machine comprises a welding device, a pressurizing device, a control device and a progressive positioning feeding mechanism. The progressive positioning feeding mechanism comprises a rack, a pushing guide rail, a material bearing plate, a swing pushing motor and a linkage assembly. Rotation input of the motor is converted into two-stage composite motion of the material bearing plate through the double-swing-rod linkage assembly, mechanical self-locking is achieved at the end point through mechanism characteristics, and therefore high repeated positioning precision and anti-interference capacity are guaranteed on the mechanical level. By means of the design, the movement process is optimized, tail end impact is eliminated, a mold and materials are protected, dependence on a high-precision guide rail and a complex control system is remarkably reduced, control is simplified, cost is reduced, the feeding mechanism cooperates with stations such as welding and demolding, full-process automation is achieved, and production efficiency and product consistency are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of thermomelting technology, and in particular to a TPU inflatable product welding machine with precise positioning function and its welding method. Background Technology

[0002] High-frequency welding technology is widely used in the sealing and molding of multi-layer composite materials for TPU (thermoplastic polyurethane) inflatable products (such as inflatable mattresses, swimming pools, and toys) due to its advantages such as high efficiency, cleanliness, and strong welds. This process typically involves stacking multiple layers of TPU film with reinforcing fabric, placing them between upper and lower molds, and then using a high-frequency electric field to cause the TPU molecules to melt through frictional heat, bonding them together under pressure.

[0003] In existing technologies, there are two main methods for automatically feeding and removing materials from the welding station: one is manual operation, which is inefficient, relies on operator experience for positioning accuracy, results in poor product consistency, and poses safety hazards; the other is using linear drive devices, such as cylinders or electric push rods. While the latter achieves automation, it has significant shortcomings in applications requiring long strokes and high-precision positioning. First, simple linear drives are prone to impacts or overtravel at the end of the stroke due to inertia, leading to inaccurate material alignment within the mold and affecting the quality and airtightness of the weld seam. Second, achieving high repeatability (e.g., ±0.1mm) places extremely high demands on the linear guides, drive system, and control system, significantly increasing costs. Finally, its motion process is simplistic, making it difficult to achieve an optimal balance between high-speed operation and precise positioning. Summary of the Invention

[0004] The purpose of this invention is to provide a TPU inflatable product welding machine with precise positioning function. Through a linkage component, the rotational motion of the drive motor is converted into a material support plate. It adopts a two-stage compound motion of rapid linear movement followed by smooth and precise feeding. The mechanical structure itself achieves precise positioning and self-locking of the endpoint, reducing the dependence on the accuracy of the control system. Furthermore, it provides a fully automatic welding machine including this feeding mechanism and a matching welding method, realizing full-process automation from material laying, precise feeding, welding, cooling and demolding to automatic reset, thereby effectively improving production efficiency and product consistency.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A TPU inflatable product welding machine with precise positioning function includes a welding device, a pressurizing device and a control device, and also includes a progressive positioning feeding mechanism; the progressive positioning feeding mechanism is located on one side of the welding device to accurately feed the material to the welding device.

[0007] The progressive positioning and feeding mechanism includes: a frame, a push guide rail, a material support plate, a swing push motor, and a linkage component;

[0008] The push guide rail is located on both sides of the frame; the material support plate is movably mounted on the push guide rail for supporting materials; the swing push motor is located in the middle of the frame; the linkage component is connected between the output end of the swing push motor and the material support plate; the control device 13 is connected to the welding device, the pressurizing device and the progressive positioning feeding mechanism respectively for coordinating and controlling their operation.

[0009] The linkage component, driven by the swing push motor, can sequentially drive the material support plate to perform a first-stage linear movement and a second-stage compound movement, so as to accurately position the material support plate from the initial loading position to the preset position of the welding device.

[0010] Furthermore, the linkage component includes a first swing arm and a second swing arm. One end of the first swing arm is hinged to the output end of the swing push motor, and the other end of the first swing arm is hinged to one end of the second swing arm via a connector. The other end of the second swing arm is hinged to the material support plate.

[0011] Furthermore, the connecting member includes a hinge post disposed at the other end of the first swing rod, a vertical hinge block sleeved on the hinge post, a horizontal hinge block connected to one side of the vertical hinge block, a second swing rod passing through the horizontal hinge block, and a fixed block connected to the material support plate at both ends of the second swing rod.

[0012] Furthermore, the vertical hinge block and the horizontal hinge block are fixed by screws to form an integral sleeve structure.

[0013] Furthermore, the welding device includes a base, a top plate, an upper mold, and a lower mold. The pressure device is located on the top plate, and the lower mold is located on the upper end of the base. The pressure device includes a hydraulic cylinder, and the piston rod of the hydraulic cylinder is connected to a lower pressure plate. The upper mold is located at the bottom end of the lower pressure plate. The base is also provided with ejector plates at both ends. The upper end of the ejector plate is provided with a positioning guide rail to facilitate secondary movement of the material support plate. The upper mold and the lower mold are electrically connected to a high-frequency generator as high-frequency electrodes to form a high-frequency welding head.

[0014] Furthermore, it also includes a demolding cylinder, which is located beside the lower mold and is used to lift and demold the positioning guide rail, the support plate and the molded product on it after the welding is completed.

[0015] Furthermore, a pulley is provided between the bottom end of the material support plate and the push guide rail.

[0016] A method for welding TPU inflatable products using a welding machine with precise positioning function includes the following steps:

[0017] S1. Material laying: Lay the multi-layer composite material to be welded on the material support plate located at the initial material loading position;

[0018] S2. Progressive feeding: Start the swing push motor, and drive the support plate to move linearly along the push guide rail in the first stage through the linkage component, and then carry out the second stage of compound motion until the support plate is accurately positioned to the preset position of the welding device.

[0019] S3. Welding and forming: Control the pressurizing device to drive the welding device to close the mold and apply pressure to the material, while starting the welding device to heat and weld, and maintain for a preset time;

[0020] S4. Cooling and demolding: After stopping heating and maintaining pressure for cooling, the welding device opens the mold and the ejection mechanism lifts up the support plate and the molded product.

[0021] S5. Reset: Control the swing push motor to reverse, and drive the material plate to return along the reverse path of the compound motion of the second stage and the linear movement of the first stage through the linkage component, and reset to the initial loading position.

[0022] Further, in step S2, the linear movement in the first stage is achieved by the swinging push motor driving the first swing arm to swing, which directly drives the material support plate to move along the push guide rail; the compound movement in the second stage is achieved by the first swing arm driving the second swing arm through the connecting member, which in turn drives the material support plate to move along a compound trajectory constrained by the two swing arms, and reaches a mechanical self-locking position at the end point.

[0023] Further, in step S1, the multilayer composite material includes, from bottom to top, a bottom anti-adhesion cloth, a nylon cloth, a multilayer TPU film, a nylon cloth, and a top anti-adhesion cloth, with insulating paper sandwiched between the TPU films; in step S3, the welding device is a high-frequency welding die head, and the preset time is 25-30 seconds.

[0024] This invention offers the following advantages: By using a double-rocker linkage assembly, the rotational input of the motor is converted into a two-stage composite motion of the material support plate, and mechanical self-locking is achieved at the endpoint using the mechanism's characteristics, thus ensuring high repeatability and anti-interference capability at the mechanical level. This design not only optimizes the motion process and eliminates end-effector impact, protecting the mold and material, but also significantly reduces reliance on high-precision guideways and complex control systems, simplifying control and lowering costs. This feeding mechanism, in conjunction with welding, demolding, and other stations, achieves full-process automation, greatly improving production efficiency and product consistency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention.

[0026] Figure 2 This is an exploded structural diagram of the progressive positioning and feeding mechanism of the present invention.

[0027] Figure 3 This is the present invention. Figure 2 A magnified view of a portion of the image.

[0028] In the picture:

[0029] 1. Hydraulic cylinder; 2. Upper fixed plate; 3. Lower pressure plate; 4. Demolding cylinder; 5. Material support plate; 6. Upper mold; 7. Push guide rail; 8. First swing arm; 9. Lower mold; 10. Swing push motor; 11. Second swing arm; 12. Base; 13. Control device; 14. Connecting parts; 100. Welding device; 200. Pressurizing device; 300. Progressive positioning and feeding mechanism. Detailed Implementation

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] Reference Figures 1-3 A TPU inflatable product welding machine with precise positioning function includes a welding device 100, a pressurizing device 200, a progressive positioning and feeding mechanism 300, and a control device 13. The welding device 100 and the pressurizing device 200 are existing technologies and will not be described in detail here.

[0032] The progressive positioning and feeding mechanism 300 is located on one or both sides of the welding device 100. It accurately and smoothly feeds the stacked multi-layered materials into the welding station. The progressive positioning and feeding mechanism 300 includes a frame, push guide rails 7, a support plate 5, a swing push motor 10, and a linkage assembly. Two parallel push guide rails 7 are fixedly installed on both sides of the frame. The support plate 5 is movably mounted on the push guide rails 7 via pulleys at its bottom to support the materials to be welded. The swing push motor 10 is preferably a servo motor or stepper motor with a brake and reducer, and is fixedly installed in the middle of the frame.

[0033] The linkage assembly converts the rotational oscillation of the output shaft of the oscillating push motor 10 into a specific trajectory movement of the support plate 5. In this embodiment, the linkage assembly includes a first swing arm 8 and a second swing arm 11. One end of the first swing arm 8 is hinged to the output shaft of the oscillating push motor 10, and the other end is hinged to one end of the second swing arm 11 via a connector. The other end of the second swing arm 11 is hinged to the bottom of the support plate 5. In this embodiment, the connector is specifically a sleeve structure, which includes a vertical hinge block sleeved on the hinge post at the end of the first swing arm 8, and a horizontal hinge block fixedly connected to the vertical hinge block via a screw. The second swing arm 11 is rotatably inserted into the horizontal hinge block, and its two ends are connected to the support plate 5 via fixed blocks. This design enables the linkage assembly to form a four-bar linkage with a defined kinematic chain.

[0034] When the swing push motor 10 drives the first swing arm 8 to swing from the initial position, the four-bar linkage will sequentially drive the material support plate 5 to perform two stages of motion.

[0035] First stage (rapid linear movement segment): The initial swing of the first swing arm 8 directly pushes the second swing arm 11 through the sleeve structure, causing the second swing arm 11 to mainly produce translational motion, thereby driving the material support plate 5 to move rapidly along the push guide rail 7 in an approximately linear manner, quickly approaching the welding station.

[0036] The second stage (smooth composite motion phase): After the first swing arm 8 swings to near the middle position, the linkage component enters a motion transition zone. At this time, the interaction between the first swing arm 8 and the second swing arm 11 changes the motion trajectory of the second swing arm 11, driving the support plate 5 to make a final smooth feed along a composite trajectory (containing a small arc and a precise translation component) constrained by the two swing arms. The speed decreases and the inertial impact is small in this stage. When the swing push motor 10 moves to the preset end angle, the entire four-bar linkage approaches or reaches the position near the "dead point", generating a mechanical self-locking effect, thereby firmly and accurately locking the support plate 5 on the preset position of the welding device 100, with high repeatability.

[0037] The welding device 100 includes a base 12, a top plate, an upper mold 6, and a lower mold 9. The lower mold 9 is fixed to the upper end of the base 12. The pressurizing device 200 includes a hydraulic cylinder 1 mounted on the top plate. The piston rod of the hydraulic cylinder 1 is connected downward to a lower pressure plate 3, and the upper mold 6 is mounted on the bottom end of the lower pressure plate 3. The upper mold 6 and the lower mold 9 serve as high-frequency electrodes and are electrically connected to an external high-frequency generator to form a high-frequency welding die head for heating and welding TPU materials. Demolding plates are also provided at both ends of the base 12. Positioning guide rails are provided at the upper ends of the demolding plates to provide auxiliary guidance and final precise positioning support for the material support plate 5 when it enters the second stage of composite motion.

[0038] A demolding cylinder 4 is provided on the side of the lower mold 9. After the welding is completed, the piston rod of the demolding cylinder 4 extends and lifts the demolding template, positioning guide rail, and the material support plate 5 on it together with the molded product, so that they are separated from the lower mold 9, which facilitates demolding.

[0039] The control device 13 (such as a PLC controller) is electrically connected to the swing push motor 10, hydraulic cylinder 1, high frequency generator and demolding cylinder 4, etc., and is used to coordinate and control the automatic operation of the entire welding process.

[0040] The welding method of the present invention includes the following steps:

[0041] S1. Material laying: On the material support plate 5 located at the initial material loading position, lay the bottom layer of anti-stick cloth, nylon cloth, multi-layer TPU film (with insulating paper sandwiched between the layers), nylon cloth and top layer of anti-stick cloth in sequence from bottom to top to form a multi-layer composite material to be welded.

[0042] S2. Progressive feeding: Control device 13 starts the swing push motor 10. The motor drives the linkage component, so that the support plate 5 successively goes through the first stage of linear movement and the second stage of compound movement, and finally accurately positions it to the welding station and is fixed by mechanical self-locking.

[0043] S3. Welding and Molding: Control device 13 activates hydraulic cylinder 1, driving upper mold 6 to press down and close with lower mold 9, applying stable pressure to the material. Simultaneously, the high-frequency generator is activated, generating a high-frequency electric field between upper mold 6 and lower mold 9, causing the TPU film molecules to generate frictional heat and melt, bonding with the nylon fabric under pressure. Maintain the welding pressure and high-frequency action for 25-30 seconds.

[0044] S4. Cooling and Demolding: Turn off the high-frequency generator and maintain the mold closing pressure to allow the weld to cool and solidify. Then, hydraulic cylinder 1 returns to open the mold. Next, start the demolding cylinder 4 to lift the support plate 5 and the molded product for demolding.

[0045] S5. Reset: Control the swing push motor 10 to reverse, and the linkage component drives the material support plate 5 to move along the reverse path of the original motion trajectory. First, it performs the second stage of reverse compound motion, and then performs the first stage of reverse linear movement, smoothly returning to the initial loading position. The finished product is taken away manually or by a robot and new material is placed. The cycle begins.

[0046] This invention, through a clever double-rocker linkage structure, organically combines two stages of motion—rapid approach and slow, precise positioning—in a purely mechanical manner. It also utilizes the mechanism's characteristics to achieve self-locking at the endpoint, significantly improving the feeding and positioning accuracy and reliability. This reduces reliance on sensors and closed-loop control systems, resulting in a stable structure and high cost-effectiveness.

[0047] The above description is only a preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included in the scope of this patent application.

Claims

1. A TPU inflatable product welding machine with precise positioning function, comprising a welding device (100), a pressurizing device (200), and a control device (13), characterized in that, It also includes a progressive positioning and feeding mechanism (300); the progressive positioning and feeding mechanism (300) is located on one side of the welding device (100); The progressive positioning and feeding mechanism (300) includes: a frame, a push guide rail (7), a support plate (5), a swing push motor (10), and a linkage component; The push guide rail (7) is disposed on both sides of the frame; the material support plate (5) is movably disposed on the push guide rail (7); the swing push motor (10) is disposed in the middle of the frame; the linkage component is connected between the output end of the swing push motor (10) and the material support plate (5); the control device 13 is connected to the welding device (100), the pressurizing device (200) and the progressive positioning feeding mechanism (300) respectively. The linkage component, driven by the swing push motor (10), can sequentially drive the material support plate (5) to perform a first stage of linear movement and a second stage of compound movement, so as to accurately position the material support plate (5) from the initial loading position to the preset position of the welding device (100).

2. The TPU inflatable product welding machine with precise positioning function according to claim 1, characterized in that, The linkage component includes a first swing arm (8) and a second swing arm (11). One end of the first swing arm (8) is hinged to the output end of the swing push motor (10), and the other end of the first swing arm (8) is hinged to one end of the second swing arm (11) through a connector (14). The other end of the second swing arm (11) is hinged to the material support plate (5).

3. The TPU inflatable product welding machine with precise positioning function according to claim 2, characterized in that, The connector (14) includes a hinge post at the other end of the first rocker arm (8), a vertical hinge block is sleeved on the hinge post, a horizontal hinge block is connected to one side of the vertical hinge block, and the second rocker arm (11) is inserted through the horizontal hinge block. Both ends of the second rocker arm (11) are connected to a fixed block that is connected to the material support plate (5).

4. A TPU inflatable product welding machine with precise positioning function according to claim 3, characterized in that, The vertical hinge block and the horizontal hinge block are fixed by screws to form an integral sleeve structure.

5. A TPU inflatable product welding machine with precise positioning function according to claim 1, characterized in that, The welding device (100) includes a base (12), a top plate, an upper mold (6), and a lower mold (9). The pressure device (200) is located on the top plate, and the lower mold (9) is located on the upper end of the base (12). The pressure device (200) includes a hydraulic cylinder (1). The piston rod of the hydraulic cylinder (1) is connected to a lower pressure plate (3). The upper mold (6) is located at the bottom end of the lower pressure plate (3). The base (12) is also provided with a stripping template at both ends. The upper end of the stripping template is provided with a positioning guide rail to facilitate the secondary movement of the material support plate (5). The upper mold (6) and the lower mold (9) are electrically connected to a high-frequency generator as high-frequency electrodes to form a high-frequency welding head.

6. A TPU inflatable product welding machine with precise positioning function according to claim 5, characterized in that, It also includes a demolding cylinder (4), which is located on the side of the lower mold (9) and is used to lift the positioning guide rail, the material support plate (5) and the molded product on it after the welding is completed to demold.

7. A TPU inflatable product welding machine with precise positioning function according to claim 1, characterized in that, A pulley is provided between the bottom end of the material support plate (5) and the push guide rail (7).

8. A method for welding TPU inflatable products using a welding machine with precise positioning function, characterized in that, Includes the following steps: S1. Laying material: Lay the multi-layer composite material to be welded on the material support plate (5) located at the initial feeding position; S2. Progressive feeding: Start the swing push motor (10), drive the support plate (5) along the push guide rail (7) to first perform the first stage of linear movement, and then perform the second stage of compound movement until the support plate (5) is accurately positioned at the preset position of the welding device (100). S3. Welding and forming: The control pressure device (200) drives the welding device (100) to close the mold and apply pressure to the material. At the same time, the welding device (100) is started to heat and weld, and the process is maintained for a preset time. S4. Cooling and demolding: After stopping heating and maintaining pressure cooling, the welding device (100) opens the mold and the ejection mechanism lifts up the support plate (5) and the molded product; S5. Reset: Control the swing push motor (10) to reverse, and drive the material support plate (5) to return along the reverse path of the compound motion of the second stage and the linear movement of the first stage through the linkage component, and reset to the initial loading position.

9. The welding method according to claim 8, characterized in that, In step S2, the linear movement in the first stage is achieved by the swing push motor (10) driving the first swing rod (8) to swing, and directly driving the material support plate (5) to move along the push guide rail (7); the compound movement in the second stage is achieved by the first swing rod (8) driving the second swing rod (11) through the connector (14), thereby driving the material support plate (5) to move along a compound trajectory constrained by the two swing rods, and reaching a mechanical self-locking position at the end point.

10. The welding method according to claim 9, characterized in that, In step S1, the multilayer composite material includes, from bottom to top, a bottom anti-adhesion cloth, a nylon cloth, a multilayer TPU film, a nylon cloth, and a top anti-adhesion cloth, with insulating paper sandwiched between the TPU films; in step S3, the welding device (100) is a high-frequency welding die head, and the preset time is 25-30 seconds.

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