An ultrasonic welding device automatically adjusts the waist circumference pitch

Abstract

The utility model relates to welding equipment technical field, concretely relates to a kind of device of ultrasonic welding automatic adjustment waist circumference pitch.The device of ultrasonic welding automatic adjustment waist circumference pitch of the present application, including frame, ultrasonic welding head and the support roller and liftable press roll of front direction.Press roll is driven by the precision transmission mechanism consisting of driving motor, synchronous pulley, double screw and screw sleeve.Its core is to dynamically adjust the tension of waist circumference material entering welding zone by lifting press roll: press roll is adjusted to tighten material, and finished product pitch increases after welding;press roll is adjusted to relax material, and finished product pitch decreases after welding.The utility model realizes the on-line automatic stepless adjustment of welding pitch, replaces the mode of traditional replacement bottom roll, and significantly improves production flexibility and efficiency.

Description

Technical Field

[0001] This utility model relates to the field of welding equipment technology, specifically to a device for automatically adjusting the waist pitch in ultrasonic welding. Background Technology

[0002] Ultrasonic welding technology is widely used in the production of disposable hygiene products due to its advantages such as high efficiency, cleanliness, and the absence of glue or solvents, especially in the elastic lamination process of waistbands in products like pull-up diapers. The welding quality of the waistband directly determines the product's wearing comfort, fit, and the stability and speed of the entire production line.

[0003] In existing technologies, ultrasonic welding of waistband elastic bands typically involves clamping the elastic band between upper and lower layers of nonwoven fabric and fixing it by pressure welding using an ultrasonic welding head and a bottom roller (anvil roller). However, traditional welding devices have significant limitations: First, adjusting the welding spacing (i.e., the distance between adjacent weld points, or "pitch") usually relies on replacing bottom rollers with different tooth spacings or performing cumbersome manual mechanical adjustments, making it impossible to achieve rapid, automatic adjustments during production based on product specifications or process requirements. Second, when production line speed changes or the incoming material (such as the number of nonwoven fabric layers or elastic band tension) fluctuates, the fixed welding pressure and spacing cannot adapt adaptively, easily leading to poor welding results, such as incomplete welds, over-welds, or material damage. In severe cases, it can even cause downtime or damage to the expensive ultrasonic generator. Furthermore, existing devices struggle to flexibly adapt to the welding needs of other auxiliary elastic materials (such as S-shaped elastic bands) while applying the main waistband elastic band.

[0004] While some technologies have been developed to improve the automation of ultrasonic welding—for example, by integrating pressure sensors and servo motors to adjust the welding head position in real time to control welding force, or by monitoring generator power to adjust the gap between the welding head and rollers—these solutions primarily focus on maintaining the constantness of the welding pressure or gap itself. They do not fundamentally address how to actively and precisely set and adjust the core process parameter of welding pitch based on the elasticity requirements of the final product's waistline. In particular, existing technologies lack a simple and reliable mechanical solution for indirectly and precisely controlling the pitch after shrinkage of the finished product by directly adjusting the material's tension state before welding. Summary of the Invention

[0005] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a device for automatically adjusting the waistline pitch in ultrasonic welding. Its core lies in using a precisely adjustable pressure roller assembly to dynamically control the tension of the waistline material entering the welding area, thereby achieving online automatic adjustment of the welding pitch without the need to replace the bottom roller or perform complex manual settings.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A device for automatically adjusting the waist pitch of ultrasonic welding includes a frame, an ultrasonic welding head is mounted on the frame, a support roller is mounted at the bottom of the ultrasonic welding head, a pressure roller is provided at the output end of the support roller, a transmission mechanism for adjusting its position is connected to the pressure roller, an adjustment mechanism is mounted on the transmission mechanism, the adjustment mechanism includes a fixed bearing and a rotating rod, the inner ring of the fixed bearing is fixedly connected to the rotating rod, and the pressure roller is fixedly connected to the end of the rotating rod.

[0007] Furthermore, the transmission mechanism includes a screw, a screw sleeve, and a transmission plate. The screw is disposed at the top and bottom of the frame, the screw sleeve is threadedly connected to the surface of the screw, and the transmission plate is fixedly connected to the side of the screw sleeve near the fixed bearing. The side of the transmission plate near the fixed bearing is fixedly connected to the fixed bearing.

[0008] Furthermore, the screw includes a first screw and a second screw, which are mounted vertically and parallel to each other on the frame.

[0009] Furthermore, the first screw and the second screw are symmetrically arranged on both sides of the pressure roller to provide a balanced and stable lifting force.

[0010] Furthermore, a drive mechanism is provided at the top of the screw, the drive mechanism including a drive motor mounted on the top of the frame, the output end of the drive motor is provided with a drive wheel, and a driven wheel is connected to the drive wheel via a transmission belt.

[0011] Furthermore, the driving wheel is fixedly connected to the top end of the first screw, and the driven wheel is fixedly connected to the top end of the second screw, ensuring that the two screws rotate synchronously.

[0012] Furthermore, the bottom ends of both the first screw and the second screw are connected to the frame via a first bearing, and the outer ring of the first bearing is fixed to the frame.

[0013] Furthermore, the top ends of both the first screw and the second screw are connected to the frame via a second bearing, and the outer ring of the second bearing is fixed to the frame.

[0014] Furthermore, guide wheels are installed at both ends of the support roller and the pressure roller along their axial direction to ensure that the material does not deviate during transmission and tension adjustment.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial effects: 1. Automatically Adjustable Pitch: By controlling the up-and-down position of the pressure rollers via a drive motor, the tension of the waistband material before welding can be precisely adjusted. When the material is tensioned, the initial welding pitch is lengthened; when relaxed, the waistband elastic contracts, resulting in a smaller welding point pitch on the final product. Conversely, when the pressure rollers press down, the material relaxes, resulting in a shorter initial welding pitch and a larger finished product pitch. This principle achieves indirect and effective control of the finished product pitch through a single mechanical action.

[0016] 2. High adaptability and improved efficiency: It can quickly adapt to the different requirements of different specifications of products for waist circumference telescopic pitch without stopping the machine to replace the bottom roller or perform complex calibration, which significantly improves the flexibility of the production line and the efficiency of production changeover.

[0017] 3. Stable structure and precise control: The twin-screw synchronous drive mechanism ensures smooth and unbiased movement of the pressure roller during lifting and lowering. The screw drive itself has self-locking properties and high positioning accuracy, which can stabilize the pressure roller at any set position, thereby ensuring the repeatability and consistency of pitch adjustment.

[0018] 4. Simplified process and reduced costs: The device has a relatively simple structure and is easy to integrate into existing production lines. By automatically adjusting the pitch, it reduces reliance on and inventory of dedicated bottom rollers, thereby lowering production costs and maintenance complexity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the ultrasonic welding automatic waist pitch adjustment device in a preferred embodiment of the present invention; Figure 2 This is a cross-sectional view of the ultrasonic welding automatic waist pitch adjustment device in a preferred embodiment of the present invention; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is a side view of the ultrasonic welding automatic waist pitch adjustment device in a preferred embodiment of the present invention.

[0020] Reference numerals in the attached drawings: 1. Frame; 2. Ultrasonic welding head; 3. Support roller; 4. Pressure roller; 5. Transmission mechanism; 51. First screw; 52. Second screw; 53. Screw sleeve; 54. Transmission plate; 6. Adjustment mechanism; 61. Fixed bearing; 62. Rotating rod; 7. Drive mechanism; 71. Drive motor; 72. Driving wheel; 73. Conveyor belt; 74. Driven wheel; 8. First bearing; 9. Second bearing; 10. Guide wheel. Detailed Implementation

[0021] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0022] Reference Figures 1-4 As shown in the preferred embodiment of this utility model, an ultrasonic welding automatic waist pitch adjustment device mainly includes a frame 1, an ultrasonic welding head 2, a support roller 3, a pressure roller 4, a transmission mechanism 5, an adjustment mechanism 6, and a drive mechanism 7.

[0023] The frame 1 serves as the main support for the entire device. The ultrasonic welding head 2 is fixed to the crossbeam of the frame 1 via its own mounting base, and its ultrasonic generator (not shown in the figure, usually external) provides the energy required for welding. Directly below the ultrasonic welding head 2, a support roller 3 is installed. The position of the support roller 3 is relatively fixed, and its main function is to support and guide the material. To the right of the support roller 3 (along the material travel direction), a pressure roller 4 is arranged side by side.

[0024] The pressure roller 4 is the core actuator for pitch adjustment in this application. It is not simply fixed, but connected to a precision lifting system. Specifically, the pressure roller 4 is connected to the transmission mechanism 5 via an adjustment mechanism 6. The adjustment mechanism 6 includes a fixed bearing 61 and a rotating rod 62. The outer ring of the fixed bearing 61 is fixed, and its inner ring is fixedly connected to one end of the rotating rod 62. The pressure roller 4 is mounted on the other end of the rotating rod 62 via a bearing (not shown separately in the figure), allowing the pressure roller 4 to rotate freely. This design allows the transmission mechanism 5 to drive the entire adjustment mechanism 6 and the pressure roller 4 to move vertically, while ensuring that the pressure roller 4 rotates smoothly with the material when in contact with it, avoiding scratching the material.

[0025] The transmission mechanism 5 is responsible for converting the rotational motion of the drive mechanism 7 into the linear motion of the pressure roller 4. A preferred embodiment includes two vertically and parallelly mounted screws, namely a first screw 51 and a second screw 52. The upper and lower ends of the two screws are connected to the top and bottom frames of the frame 1 via a second bearing 9 and a first bearing 8, respectively, ensuring flexible rotation and fixed position. Each screw is fitted with a threaded sleeve 53. The sides of the two sleeves 53 are jointly fixedly connected to a vertical transmission plate 54. The outer ring of the fixed bearing 61 of the adjusting mechanism 6 is fixedly mounted on this transmission plate 54. Therefore, when the first screw 51 and the second screw 52 rotate synchronously, the two sleeves 53 will drive the transmission plate 54, the adjusting mechanism 6, and the pressure roller 4 to perform precise up-and-down linear motion together.

[0026] To ensure the synchronicity and smoothness of the lifting and lowering of the pressure roller 4, the first screw 51 and the second screw 52 are preferably symmetrically arranged on both sides of the pressure roller 4 or the transmission plate 54. The drive mechanism 7 provides power and includes a drive motor 71 (preferably a servo motor or stepper motor for precise control) mounted on the top of the frame 1. A drive wheel 72 is mounted on the output shaft of the drive motor 71. The top end of the first screw 51 is fixedly connected to the drive wheel 72. A driven wheel 74 is fixedly connected to the top end of the second screw 52, ​​and the drive wheel 72 and the driven wheel 74 are connected by a transmission belt 73 (such as a synchronous belt). Thus, when the drive motor 71 starts, it synchronously drives the two screws to rotate in the same direction and at the same speed, achieving smooth lifting and lowering of the pressure roller 4.

[0027] In addition, guide wheels 10 are installed at both ends of the support roller 3 and the pressure roller 4. These guide wheels 10 play a crucial role in correcting and limiting the movement of the material (especially the soft nonwoven composite layer), preventing lateral deviation during tension changes and ensuring the accuracy of the welding path. The working principle and process of this utility model are as follows: During production, the composite layer consisting of the upper non-woven fabric, the waist elastic band, and the lower non-woven fabric first passes between the support roller 3 below and the pressure roller 4 above. At this time, the height of the pressure roller 4 driven by the transmission mechanism 5 determines the wrap angle and tension of the material in this area.

[0028] When producing products with smaller weld pitch after waist shrinkage, the control system instructs the drive motor 71 to rotate, which in turn moves the pressure roller 4 downward via a screw drive. The downward pressure of the pressure roller 4 relaxes the material's path before welding, reducing tension. The material then enters the welding area between the ultrasonic welding head 2 and the rotating bottom roller (anvil roller). Under lower tension, the material is welded in a relatively "natural" or "shrunken" state, resulting in a smaller initial weld pitch. Once welding is complete and the waist elastic has freely shrunk, the final weld pitch on the finished product is correspondingly smaller.

[0029] Conversely, when a product with a larger finished pitch needs to be produced, the drive motor 71 rotates in the opposite direction, lifting the pressure roller 4 upwards. The lifting of the pressure roller 4 tightens the material, increasing the tension in its forward direction. The material, under tension, enters the welding zone, and the pitch fixed by welding is in an elongated state. After welding is completed and the external force is released, the elastic band around the waist will contract, but the rebound of the spacing fixed by the weld points is limited, resulting in a larger weld point pitch in the final product.

[0030] Through prior process testing and calibration, the precise position of the pressure roller 4 and the waist pitch of the final product can be established. In actual production, operators or the central control system only need to set the target pitch value according to the product specifications to automatically drive the pressure roller 4 to the corresponding position, achieving rapid, automatic, and precise adjustment of the waist pitch.

[0031] Without causing conflict, those skilled in the art can freely combine and use the above-mentioned additional technical features.

[0032] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this utility model.

Claims

1. A device for automatically adjusting the waist circumference pitch in ultrasonic welding, characterized in that: The device includes a frame on which an ultrasonic welding head is mounted. A support roller is mounted at the bottom of the ultrasonic welding head. A pressure roller is provided at the output end of the support roller. A transmission mechanism for adjusting the position of the pressure roller is connected to the pressure roller. An adjustment mechanism is mounted on the transmission mechanism. The adjustment mechanism includes a fixed bearing and a rotating rod. The inner ring of the fixed bearing is fixedly connected to the rotating rod, and the pressure roller is fixedly connected to the end of the rotating rod.

2. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 1, characterized in that: The transmission mechanism includes a screw, a screw sleeve, and a transmission plate. The screw is disposed at the top and bottom of the frame. The screw sleeve is threadedly connected to the surface of the screw. The transmission plate is fixedly connected to the side of the screw sleeve near the fixed bearing. The side of the transmission plate near the fixed bearing is fixedly connected to the fixed bearing.

3. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 2, characterized in that: The screw includes a first screw and a second screw, which are mounted vertically and parallel to each other on the frame.

4. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 3, characterized in that: The first screw and the second screw are symmetrically arranged on both sides of the pressure roller.

5. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 4, characterized in that: The top of the screw is provided with a drive mechanism, which includes a drive motor mounted on the top of the frame. The output end of the drive motor is provided with a drive wheel, and a driven wheel is connected to the drive wheel via a transmission belt.

6. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 5, characterized in that: The driving wheel is fixedly connected to the top end of the first screw, and the driven wheel is fixedly connected to the top end of the second screw.

7. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 6, characterized in that: The bottom ends of the first screw and the second screw are both connected to the frame via a first bearing, and the outer ring of the first bearing is fixed to the frame.

8. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 7, characterized in that: The top ends of the first screw and the second screw are both connected to the frame via a second bearing, and the outer ring of the second bearing is fixed to the frame.

9. The device for automatically adjusting the waist pitch of ultrasonic welding according to claim 1, characterized in that: Guide wheels are installed at both ends of the support roller and the pressure roller along their axial direction.

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