Ultrasonic welding head, welding device and ultrasonic welding head balanced regulation and control design method

Abstract

The application provides an ultrasonic welding head, which comprises a welding head body, wherein a cylindrical regulating hole penetrating in the width direction is arranged in the middle of the welding head body, the cylindrical regulating hole is coaxially arranged with the welding head body, and the radius R of the cylindrical regulating hole is determined by R = (W / L) ^ (1 / 2) * eta, wherein W and L are the width and length of the welding head body respectively, and eta is an area ratio factor, and the range of eta is 0.2-0.4. By arranging the cylindrical regulating hole penetrating in the width direction and coaxially arranged in the middle of the welding head body, the longitudinal stiffness of the central region of the welding head body can be precisely weakened, the static pressure is uniformly distributed from the center to both sides, the distribution imbalance problem of the wide welding head body that the pressure is large in the middle and small at the edge is significantly improved, and the problems of overwelding in the center and virtual welding at the edge are avoided.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to an ultrasonic welding head, a welding device, and a design method for balanced control of the ultrasonic welding head. Background Technology

[0002] Ultrasonic welding is a joining process that uses high-frequency vibration to achieve molecular fusion of materials. In welding large-size, wide-width workpieces, the welding head body must simultaneously satisfy longitudinal vibration transmission and uniform static pressure distribution to ensure welding consistency. Due to their large length and width, wide-width welding heads are susceptible to the Poisson effect during operation, resulting in a deviation from a uniform state in vibration energy and force distribution.

[0003] To improve vibration distribution, existing wide-amplitude ultrasonic welding heads often employ longitudinal slots or central openings, attempting to adjust stiffness by removing some material, suppress lateral parasitic vibrations, and alleviate central energy accumulation. Some solutions modify the mass and stiffness distribution of the welding head body through simple hole cutting, aiming to optimize end-face amplitude and pressure output.

[0004] However, existing perforation structures are mostly based on empirical qualitative design and have not established quantitative calculation rules for aperture related to the length and width of the welding head body. This makes it impossible to accurately control stiffness and sound field distribution. If the shape and size of the perforation are unreasonable, problems such as excessive central amplitude and pressure and insufficient edge energy will still occur. It is difficult to fundamentally solve the defect of uneven welding of wide welding head bodies, which leads to over-welding, incomplete welding, and poor stability of the product.

[0005] In view of this, it is necessary to improve the existing ultrasonic welding head to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an ultrasonic welding head to solve problems such as over-welding and incomplete welding that are easily generated during the welding of existing welding head bodies.

[0007] To achieve the above objectives, the present invention provides an ultrasonic welding head, comprising a welding head body, wherein a cylindrical adjustment hole extending through the center of the welding head body along its width direction is provided, the cylindrical adjustment hole being coaxially arranged with the welding head body, and the radius R of the cylindrical adjustment hole being determined by... It is determined that W and L are the width and length of the welding head body, respectively, and η is the area ratio factor, which ranges from 0.2 to 0.4.

[0008] As a further improvement of the present invention, η ranges from 0.25 to 0.3.

[0009] As a further improvement of the present invention, the value of η is 0.275.

[0010] As a further improvement of the present invention, the height H of the center of the cylindrical adjustment hole relative to the bottom of the welding head body is determined by... Determined, where h is the effective working height of the welding head body. It is the node offset coefficient. The range is between 0.4 and 0.6.

[0011] As a further improvement of the present invention The value is 0.5.

[0012] As a further improvement of the present invention, the length or width of the welding head body is greater than 25mm.

[0013] The present invention also provides a welding apparatus, the welding apparatus comprising the ultrasonic welding head as described above.

[0014] This invention also provides a method for designing an ultrasonic welding head with balanced control, for designing an ultrasonic welding head as described above, characterized by comprising the following steps:

[0015] S1: Establish a multiphysics model of the ultrasonic welding head and determine the central overload region; S2: Cylindrical control holes are selected as the control structure; S3: Determine the radius of the cylindrical control hole based on the area ratio factor.

[0016] As a further improvement of the present invention, it also includes step S4 after step S3: determining the center height of the cylindrical control hole according to the node offset coefficient.

[0017] As a further improvement of the present invention, it also includes step S5, which is located after step S4: coupling optimization to obtain an ultrasonic welding head with uniform amplitude and pressure.

[0018] The beneficial effects of this invention are as follows: By setting a cylindrical adjustment hole that runs through the width direction and is coaxially arranged in the middle of the welding head body, this invention can precisely weaken the longitudinal stiffness of the central area of ​​the welding head body, so that the static pressure is evenly distributed from the center to both sides, significantly improving the problem of uneven distribution of "high pressure in the middle and low pressure at the edge" in the wide welding head body, and avoiding over-welding in the center and poor welding at the edge. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a front structural diagram of the ultrasonic welding head of the present invention; Figure 2 This is a side view of the ultrasonic welding head of the present invention; Figure 3 This is a flowchart of the ultrasonic welding head equalization control design method of the present invention.

[0020] Reference numerals: 100, ultrasonic welding head; 1, welding head body; 2, cylindrical adjustment hole. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] like Figures 1 to 2 As shown, the ultrasonic welding head 100 of the present invention includes a welding head body 1. A cylindrical adjustment hole 2 extending through the width direction is provided in the middle of the welding head body 1. The cylindrical adjustment hole 2 is coaxially arranged with the welding head body 1, and the radius R of the cylindrical adjustment hole 2 is determined by… It is determined that W and L are the width and length of the welding head body 1, respectively, and η is the area ratio factor, which ranges from 0.2 to 0.4.

[0025] The coaxial arrangement here refers to the fact that the two have the same axis of symmetry, specifically that the axis of the cylindrical control hole 2 intersects perpendicularly with the central longitudinal axis of the welding head body 1. In addition to the welding head body 1, the ultrasonic welding head 100 also includes a coupling rod connected to the welding head body 1.

[0026] The present invention provides a cylindrical adjustment hole 2 that runs through the width direction and is coaxially arranged in the middle of the welding head body 1. This can precisely weaken the longitudinal stiffness of the central area of ​​the welding head body 1, so that the static pressure is evenly distributed from the center to both sides. This significantly improves the problem of uneven distribution of "high pressure in the middle and low pressure at the edge" in the wide welding head body 1, and avoids over-welding in the center and poor welding at the edge.

[0027] The radius of the cylindrical control hole 2 is determined by a quantitative formula based on the width W, length L and area ratio factor η of the welding head body 1. This achieves a matching design between the hole diameter and the size of the welding head body 1, which can effectively suppress lateral coupling and energy concentration towards the central axis in ultrasonic vibration, making the amplitude distribution of the welding end face more uniform and improving welding consistency and appearance quality.

[0028] The cylindrical control hole 2 is coaxially centered and runs through the structure, which is symmetrical and has a uniform stress distribution. While optimizing the acoustic-force field, it will not destroy the main vibration mode of the welding head body 1. It can reduce the stress concentration and structural fatigue risk of the welding head body 1, extend the service life of the welding head body 1, and the structure is highly versatile and can be adapted to wide-amplitude ultrasonic welding heads 100 of different sizes.

[0029] The range of η is 0.25-0.3.

[0030] To verify the influence of the area proportion factor η on the welding effect, the welding head body 1 was made of M2 high-speed steel, with a longitudinal length L of 58 mm, a welding end face width of 8 mm, and a height h of 13.85 mm. This welding head body 1 was used with an ultrasonic transducer system, with a preset operating frequency of 21 kHz. With other variables remaining constant, five sets of specific simulation data were extracted. The corresponding area proportion factors η for these data were 0.2, 0.25, 0.275, 0.3, and 0.4, respectively. This allowed for the determination of the area proportion factor... The correlation between the center pressure, amplitude uniformity, and stress distribution of the welding head body 1 is shown in the table below.

[0031]

[0032] Preferably, the value of η is 0.275.

[0033] The performance of the welding head body 1 under different area ratio factors was tested. The results showed that when the area ratio factor η was between 0.25 and 0.3, the acoustic and mechanical properties of the welding head body 1 reached an excellent balance, and all indicators met the expected design requirements.

[0034] Within this parameter range, the amplitude increase of the welding head body 1 end face is effectively controlled at a low level of 11.11% to 16.27%, ensuring a high degree of consistency in energy output at the welding end face. Simultaneously, the ratio of the center pressure to the pressure at the 1 / 4 position significantly approaches 1, greatly improving the uniformity of stress distribution. Especially when η = 0.275, the ratio of the center pressure to the pressure at the 1 / 4 position is 0.989, indicating that the stress at the center and edge of the welding head body 1 is basically consistent, effectively avoiding local overload or underload issues. Furthermore, the stress of the welding head body 1 within this range is within a safe and reasonable range, resulting in high structural reliability.

[0035] Comparative test results show that when η is 0.2 or 0.4, the performance of the welding head body 1 deteriorates significantly and fails to meet design expectations. When η=0.2, the central pressure is significantly high, which easily leads to severe central stress concentration, and the amplitude increase is as high as 33.05%, with extremely poor uniformity of end face amplitude. When η=0.4, the pressure distribution shifts in the opposite direction, with the edge pressure being much greater than the central pressure, and the amplitude increase rebounding to 31.93%. At the same time, the stress of the welding head body 1 reaches the highest value in the test group, and the structural reliability decreases significantly.

[0036] In summary, controlling the area ratio factor within the range of 0.25 to 0.3 can effectively overcome the technical challenge of simultaneously achieving both amplitude uniformity and pressure uniformity in existing technologies, providing an optimal parameter range for achieving stable and high-quality wide-amplitude ultrasonic welding.

[0037] The height H of the center of the cylindrical adjustment hole 2 relative to the bottom of the welding head body 1 is determined by... Determined, where h is the effective working height of the welding head body 1. It is the node offset coefficient. The range is between 0.4 and 0.6. By arranging the openings in the region of the vibration mode where the amplitude is low and relatively stable, the hole structure modulates the sound wave propagation path without disrupting the main vibration mode, thereby weakening the lateral coupling effect, suppressing energy accumulation towards the center, and achieving uniformity of the amplitude distribution on the end face.

[0038] Here, the bottom of the welding head body 1 refers to the end that contacts the workpiece being welded.

[0039] Preferred, The value is 0.5.

[0040] To address the influence of the node offset coefficient, the welding head body 1 was constructed of M2 high-speed steel with a longitudinal length L of 58 mm, a welding end face width of 8 mm, and a height h of 13.85 mm. This welding head body 1 was used in conjunction with an ultrasonic transducer system with a preset operating frequency of 21 kHz. Five sets of specific implementation data were extracted for verification, while controlling other variables. The coefficients corresponding to these five sets of data are 0.3, 0.4, 0.5, 0.6, and 0.7, respectively, demonstrating the relationship between this parameter and the uniformity of welding amplitude, pressure distribution, and stress in the welding head body 1. The results are shown in the table below.

[0041]

[0042] As shown in the table above, when the node offset coefficient is in the range of 0.4 to 0.6, the test results are in line with expectations, exhibiting good acoustic consistency and mechanical stability. In particular, when the coefficient is 0.5, the performance reaches an optimal state: the amplitude increase is only 8.00%, achieving extremely high energy output uniformity; simultaneously, the pressure ratio is 1.13, with the stress at the center and edge being very close. Within this range, the stress in the weld head body 1 remains stable between 9.9 and 12 MPa, ensuring a high fatigue life for the structure.

[0043] In contrast, when the coefficients were 0.3 or 0.7, the results deviated significantly from the expected range. At a coefficient of 0.3, the amplitude uniformity increased by as much as 56.76%, resulting in extremely uneven energy output and a pressure ratio of 1.68, indicating significant central overload. When the coefficient increased to 0.7, the performance further deteriorated, with the pressure ratio surging to 2.77 and the amplitude increase rebounding to 41.70%. Such drastic pressure and energy fluctuations can lead to serious defects in the weld quality.

[0044] The test results show that controlling the node offset coefficient between 0.4 and 0.6, preferably 0.5, is the key to optimizing the performance of the welding head body 1 and achieving pressure balance and uniform amplitude on the welding surface.

[0045] The method of opening a cylindrical control hole 2 is suitable for welding head body 1 with a length or width greater than 25mm and a working frequency of 15kHz-40kHz. For this type of welding head body 1, hollowing out the middle can improve the welding uniformity and pressure uniformity.

[0046] Furthermore, this embodiment also provides a welding apparatus, which includes the ultrasonic welding head 100 described above.

[0047] like Figure 3 As shown, this embodiment also provides a method for equalization control design of an ultrasonic welding head 100, which is used to design the ultrasonic welding head 100, including the following steps: S1: Establish a 100+ physics field model for the ultrasonic welding head and determine the central overload area; First, a multiphysics coupling model was established for the ultrasonic welding head 100 to analyze the stress and vibration characteristics of the solid structure. The results show that, influenced by the Poisson effect, the ultrasonic welding head 100 exhibits significant lateral coupling during operation, leading to stress concentration and amplitude accumulation in the central region, resulting in over-welding at the center, while the edge region suffers from insufficient energy, resulting in incomplete welding. Therefore, the central overload and edge underload regions are identified as the target areas for subsequent structural optimization.

[0048] S2: Cylindrical control hole 2 is selected as the control structure; A transverse through-hole structure is introduced in the central region of the welding head body 1 to achieve active control over stiffness and sound field. Simulation results comparing different topological forms such as oval holes, circular holes, triangular holes, rectangular holes, and elliptical holes reveal that the circular hole, due to its continuous and smooth boundary, exhibits less stress concentration and more uniform sound field interference, thus enabling effective control while ensuring structural stability. Therefore, the circular hole is preferred as the core control structural unit.

[0049] S3: Determine the radius of the cylindrical control hole 2 based on the area ratio factor.

[0050] Based on the dimensions of the welding head body 1, a constraint formula for the radius R of the circular hole is established. By adjusting the value of η, quantitative control of the opening size can be achieved, thereby weakening the longitudinal equivalent stiffness of the central region and guiding the load to redistribute from the center to both sides, so as to eliminate pressure peaks and achieve pressure balance.

[0051] S4: Determine the center height of cylindrical control hole 2 based on the node offset coefficient.

[0052] Establish the positioning formula for the center height H of the cylindrical control hole 2. By placing the opening in a region with a low amplitude and relatively stable vibration mode, the hole structure modulates the sound wave propagation path without disrupting the main vibration mode, thereby weakening the lateral coupling effect, suppressing energy accumulation towards the center, and achieving uniformity of the end face amplitude distribution.

[0053] S5: Coupling optimization yields an ultrasonic welding head 100 with uniform amplitude and pressure.

[0054] By combining and optimizing the two key parameters of radius and height within their respective reasonable ranges, the optimal structural parameters are determined. This method not only provides specific opening dimensions and locations but also establishes a general design criterion based on area ratio and position coefficient, which can be extended to the structural optimization design of wide-width welding head bodies of different sizes and working conditions.

[0055] Regarding the design method for 100° equalization control of ultrasonic welding heads, this embodiment provides the following specific implementation process: The welding head body 1 is made of M2 high-speed steel, with the following geometric dimensions: longitudinal length 58mm and welding end face width 8mm. This welding head body 1 is used in conjunction with an ultrasonic transducer system, with a preset operating frequency of 21kHz.

[0056] Analysis of failure phenomena in the benchmark model: Welding experiments first revealed that a solid weld head body 1 easily leads to a strong weld in the middle of the product but detachment at the edges. Therefore, multiphysics coupling simulation was performed on the initial solid, non-porous weld head body 1 for verification. The simulation results revealed extremely severe non-uniformity defects: The pressure distribution is extremely unbalanced: under a pressure of 500N, the center pressure of the solid welding head body 1 reaches -8.86MPa, while the pressure at the edge (1 / 4 position) is only -3.69MPa. The calculated pressure ratio is as high as 2.40. This means that the central region of the welding head body 1 bears more than twice the static load of the edge.

[0057] The amplitude increase range exceeded the standard: the amplitude at the center point of the weld end face was much higher than that of the edge area, with an increase of 59.50%. This extreme "peak-like" energy distribution means that the welding energy is highly concentrated near the axis of the weld head body 1.

[0058] The solid welding head body 1, due to its aspect ratio being within the acoustically sensitive range, generates strong Poisson effect coupling under ultrasonic excitation. Due to the lack of transverse interception, longitudinal vibration energy converges violently towards the central axis, forming a severe central energy-concentrating standing wave; at the same time, the longitudinal equivalent stiffness k of the central solid structure is much higher than that of the edge, making it the main static load-bearing path, resulting in a central pressure ratio as high as 2.40.

[0059] This dual overload of "dynamic amplitude" and "static pressure" directly leads to over-soldering in the center during welding; while the edge areas suffer from insufficient stress support and energy depletion, resulting in incomplete welds and detachment.

[0060] Lateral aperture selection and analysis: To correct the severe energy accumulation in the solid model, a transverse through-hole structure was introduced in this stage. The aim was to optimize the sound field distribution by altering the local mass distribution and structural stiffness. Five topological shapes (oval, circle, triangle, rectangle, and ellipse) were selected for the experiment. While maintaining the equivalent area removal, their effects on pressure, amplitude, and stress were compared. The table below summarizes the simulation results; a smaller amplitude increase is better, and a pressure ratio closer to 1 is preferable.

[0061]

[0062] Firstly, regarding holes with straight boundaries, such as rectangular and oval holes, these hole types have a strong blocking effect on longitudinal sound waves, resulting in a strong pressure redistribution capability, but they are also prone to "over-compensation." The rectangular hole reduced the pressure ratio from 2.40 to 0.31, significantly weakening the central pressure, but it was far from the ideal uniform state (close to 1), indicating a significant edge overload problem. Simultaneously, there was still significant stress concentration at its corners (17.9 MPa), and the straight boundary easily triggered sound wave reflection, affecting vibration stability. The oval hole, on the other hand, improved boundary continuity through a rounded transition, significantly reducing amplitude fluctuations (20.00%), but its pressure ratio (0.27) also deviated from 1, indicating a strong "over-compensation" phenomenon. Overall, although these hole types possess strong pressure control capabilities, they all suffer from pressure distribution imbalance.

[0063] Secondly, regarding the variable curvature holes with sharp corners (isosceles right-angled triangular holes), the control effect of this type of hole is relatively mild. The pressure ratio of the triangular hole is 1.22, which is one of the closest to 1 among all structures, indicating that it performs well in pressure homogenization and does not exhibit obvious over-adjustment problems. However, due to its asymmetrical geometry and the presence of sharp corner regions, the stress distribution is still not ideal, and the shift in the structural center of gravity leads to uneven amplitude distribution (increase of 18.49%). Therefore, this structure has advantages in pressure uniformity but shortcomings in vibration symmetry and stability.

[0064] Finally, regarding continuous curvature holes (circular and elliptical holes), these hole types have smooth boundaries and relatively uniform stress distribution, but their pressure control capabilities differ significantly. The pressure ratio of the circular hole is 0.86, close to the ideal value of 1, while its maximum stress is low (10 MPa), indicating that it provides good pressure uniformity while ensuring structural safety, making it a relatively robust solution. In contrast, although the elliptical hole significantly reduces the pressure ratio to 0.22, it deviates significantly from 1, indicating a severe pressure imbalance. Furthermore, its local stress reaches as high as 32 MPa, with a large amplitude increase (33.91%), easily leading to structural instability. Overall, the circular hole exhibits a better comprehensive balance.

[0065] In summary, the control of each hole type shows significant differences: rectangular and oval shapes exhibit over-adjustment, while elliptical shapes deviate from balance and experience excessive stress; triangular shapes have good uniformity but insufficient stability; and circular shapes demonstrate the best performance in terms of pressure balance, stress and amplitude uniformity, resulting in the best overall performance.

[0066] Optimal orifice parameter optimization: Based on the determination that a circular hole is the optimal topology, this embodiment conducts multiple comparative simulations on the hole radius R and center height H, as shown in the table below. The system analyzes the influence of the circular hole on pressure balance and amplitude consistency, and further refines a parametric model that can be used for engineering design.

[0067]

[0068] Comparative analysis of pressure distribution under different radii revealed that as the radius R increased from 2 mm to 3.29 mm, the pressure in the central region of the welding head body 1 significantly decreased, and the pressure ratio improved from 1.26 to 0.86. This indicates that appropriately increasing the aperture can effectively weaken the stiffness of the central section, allowing the load to be transferred evenly from the center to the edge, thus acting as an "elastic buffer." However, when the radius further increased to 4.5 mm, the pressure ratio actually rose to 1.53, indicating that the central load-bearing capacity was excessively weakened, leading to pressure re-concentration and adjustment failure. Therefore, a clear nonlinear relationship exists between the radius and the pressure balancing effect, suggesting the existence of an optimal value range.

[0069] From a mechanistic perspective, this process is essentially controlled by the ratio of the opening area to the cross-sectional area of ​​the welding head body 1, which determines the degree of stiffness reduction. When this ratio is within a reasonable range, uniform pressure distribution can be achieved; too small or too large a ratio will disrupt the balance.

[0070] The radius R of the cylindrical regulating hole 2 is determined by ,when The ideal center pressure unloading is achieved when the value is between 0.25 and 0.3.

[0071] Under a fixed radius, changing the position H of the circular hole in the longitudinal direction of the welding head body 1 results in a clear and regular change in the amplitude distribution. Simulation results show that when the circular hole is located in the middle of the welding head body 1 (approximately 8 mm), the amplitude increase is the lowest (approximately 16.60%), and the overall distribution is the most uniform. However, when the hole position deviates from this area (e.g., 5 mm or 9.5 mm), the amplitude increase significantly increases to 36%–45%, and the vibration uniformity deteriorates significantly. This indicates that the hole position is highly sensitive to vibration control.

[0072] The physical essence lies in the fact that the circular hole modulates the sound wave propagation path by changing the local stiffness distribution. When the hole is located in the stable region of the mode shape with a low amplitude (near the approximate modal node), the disturbance to the main vibration mode is minimized. It can effectively adjust the stiffness while maintaining the overall mode shape stability, thereby suppressing amplitude concentration and improving the uniformity of distribution. However, when the hole is located outside this region, it will cause strong interference to the sound field, resulting in uneven energy distribution and aggravated amplitude fluctuations.

[0073] From a mechanistic perspective, this process is mainly determined by the position of the opening; that is, the position of the opening in the longitudinal direction relative to the modal distribution affects the stiffness adjustment effect. The adjustment is optimal when the position is in the low amplitude region, while deviation from this position weakens the effect and causes vibration imbalance.

[0074] The height H of the center of the cylindrical adjustment hole 2 relative to the bottom of the welding head body 1 is determined by... Sure, The ideal height is between 0.4 and 0.6.

[0075] Determining the optimal parameters for the optimal hole: Within the aforementioned parameter range, multiple combinations of radius and height were selected for comparative simulation analysis. The optimal parameter combination was determined through a comprehensive evaluation of the pressure ratio and amplitude increase.

[0076] This invention provides a coaxial, through-the-width cylindrical control hole 2 in the center of the welding head body 1. By combining the area ratio factor and the node offset coefficient to quantitatively determine the hole diameter and opening height, the amplitude and pressure distribution on the end face of the wide-width welding head body 1 can be balanced, eliminating defects such as over-welding in the center and incomplete welding at the edges. The structure is symmetrical and smooth with uniform stress distribution, which can reduce stress concentration and fatigue risk, extend service life, and adapt to various sizes and frequency conditions, making it highly versatile. The supporting design method can achieve precise parameter optimization, significantly improving welding consistency and structural stability, fundamentally solving the technical problem of uneven sound field and force field distribution in large-size ultrasonic welding heads.

[0077] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An ultrasonic welding head, characterized in that: The ultrasonic welding head includes a welding head body, and a cylindrical adjustment hole extending through the width direction is provided in the middle of the welding head body. The cylindrical adjustment hole is coaxially arranged with the welding head body, and the radius R of the cylindrical adjustment hole is determined by... It is determined that W and L are the width and length of the welding head body, respectively, and η is the area ratio factor, which ranges from 0.2 to 0.

4.

2. The ultrasonic welding head according to claim 1, characterized in that: The range of η is 0.25-0.

3.

3. The ultrasonic welding head according to claim 2, characterized in that: The value of η is 0.

275.

4. The ultrasonic welding head according to claim 1, characterized in that: The height H of the center of the cylindrical adjustment hole relative to the bottom of the welding head body is determined by... Determined, where h is the effective working height of the welding head body. It is the node offset coefficient. The range is between 0.4 and 0.

6.

5. The ultrasonic welding head according to claim 4, characterized in that: The value is 0.

5.

6. The ultrasonic welding head according to any one of claims 1-5, characterized in that: The length or width of the welding head body is greater than 25mm.

7. A welding apparatus, characterized in that: The welding apparatus includes an ultrasonic welding head as described in any one of claims 1-6.

8. A method for balancing and controlling an ultrasonic welding head, used to design an ultrasonic welding head as described in any one of claims 1-6, characterized in that: Includes the following steps: S1: Establish a multiphysics model of the ultrasonic welding head and determine the central overload region; S2: Cylindrical control holes are selected as the control structure; S3: Determine the radius of the cylindrical control hole based on the area ratio factor.

9. The ultrasonic welding head equalization control design method according to claim 8, characterized in that: It also includes step S4, which follows step S3: determining the center height of the cylindrical control hole based on the node offset coefficient.

10. The ultrasonic welding head equalization control design method according to claim 9, characterized in that: It also includes step S5, which follows step S4: coupling optimization to obtain an ultrasonic welding head with uniform amplitude and pressure.

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