Large-size ultrasonic plastic welding tool head capable of effectively restraining transverse vibration and large in amplitude

Abstract

The invention discloses a large-size ultrasonic plastic welding tool head which can effectively restrain transverse vibration and is large in amplitude, first air grooves in a penetrating period are formed in the front surface and the rear surface of the tool head, second air grooves in the penetrating period are formed in the left surface and the right surface of the tool head, and air holes are formed in the upper surface and the lower surface of the tool head. The upper surface of the tool head is provided with a first groove and a second groove, the front and rear surfaces are provided with third grooves, and the left and right surfaces are provided with fourth grooves. The surface of the tool head is provided with the penetrable periodic air grooves and the air holes, an air-metal three-dimensional near-periodic phononic crystal defect structure is formed, transverse vibration of the large-size ultrasonic plastic welding tool head is restrained, the amplitude distribution uniformity is improved, the surface groove structure is formed, sound waves are localized at the defect position or transmitted along the defect, and the ultrasonic plastic welding tool head has the advantages that the ultrasonic plastic welding tool head is manufactured. The output amplitude of the welding surface of the tool head is improved, so that the welding precision and quality are improved, meanwhile, a performance prediction model of the tool head is established, and the design efficiency and design quality are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has a large amplitude. Background Art

[0002] In recent decades, the demand for plastic products has been increasing, and they have been widely used in various fields of human life and national economy. Ultrasonic plastic welding has become the mainstream plastic connection method due to its incomparable advantages. There are two key factors affecting the quality of ultrasonic plastic welding: welding strength and welding accuracy, and welding strength and welding accuracy are closely related to the performance of the welding tool head. Studies have shown that under a given ultrasonic frequency, each plastic weldment has an optimal amplitude range. Within the appropriate range, increasing the output amplitude of the tool head can improve the strength of the weld and shorten the welding time. If the amplitude is too small and does not reach the required amplitude, the weldment will be difficult to melt, resulting in insufficient welding. In addition, for large-sized tool heads that are often used in ultrasonic plastic welding, affected by the Poisson effect, the tool head will produce severe lateral vibration, which will not only cause local overflow or leakage of the weldment, seriously affecting the quality of ultrasonic plastic welding, but also cause secondary processing of the machined surface by abrasive particles, affecting the machining accuracy. Therefore, it is particularly important to effectively control the lateral vibration of large-sized tool heads, especially for weldments with high appearance requirements and precise structures.

[0003] Adachi K (Adachi K, Ueha S. Modal Vibration Control of Large Ultrasonic Tools with the Use of Wave-trapped Horns [J]. The Journal of the Acoustical Society of America, 1990, 87 (1): 208-214.) proposed a method of using an additional vibrator to control the vibration of a large-sized tool head in ultrasonic plastic welding, thereby achieving a uniform distribution of the amplitude of the radiating surface of the tool head; E. Mori (Mori E, Itoh K, Imamura A. An Analysis of Fundamental Vibration Mode of Short Column Type Resonator Using Apparent Elasticity Method [J]. Journal of the Acoustical Society of Japan, 1995, 51 (06): 455-462.) et al. applied the theory of apparent elasticity to a vibrating body with axial and radial vibrations, and derived the frequency and vibration displacement distribution equations; R. Rudramoorthy (Rani MR, Prakasan K, Rudramoorthy R. Design and Simulation of a Large Tubular Horn for Ultrasonic Plastic Welding [J]. International Journal of Design Engineering, 2014, 5 (4): 344-357.) conducted an experimental design analysis on the slotting tool head and determined the influence of slotting on the modal frequency and amplitude uniformity of the tool head; Cheng Cundi (Cheng Cundi. A new method for controlling the amplitude distribution of ultrasonic tool heads [J]. Applied Acoustics, 1991, 10 (02): 44.) used the attached elastic components and slotting to control the displacement amplitude distribution of the radiating surface of the large-sized tool head; Lin Shuyu (Lin Shuyu, Zhang Fucheng. Transverse displacement of ultrasonic plastic welding tool Research on vibration and slotting [J]. Acoustic Technology, 1992, 11(04): 24-28.) et al. used the apparent elastic method to derive the frequency formula of large-size tool heads and used the slotting method to suppress the lateral vibration of the tool head; Liang Zhaofeng (Liang Zhaofeng, Zhou Guangping, Mo Xiping, Zhang Yihui, Li Zhengzhong. A new design method for large-size long strip ultrasonic plastic welding slotting welding head [J]. Mechanical Science and Technology, 2008, 27(03): 334-337.0) (Liang Zhaofeng, Zhou Guangping, Mo Xiping, Li Zhengzhong.Design of a large-sized cubic ultrasonic plastic welding horn with a slotted structure [J]. Journal of Engineering Design, 2009, 16(03): 200-204.) The large-sized long strip and cubic tool head is divided into simple units, and the frequency equation of the tool head is solved using equivalent impedance; Cheng Zhen (Cheng Zhen, Guo Jianzhong. Optimization design of a large-sized cubic slotted ultrasonic plastic welding tool head [J]. Acoustic Technology, 2010, 29(01): 103-106.) uses the parametric analysis technology of ANSYS to take the length, slot length and width of the large-sized tool head as design parameters, and the amplitude of the large-sized slotted tool head is analyzed. The uniformity of the distribution and other indicators were optimized and designed; Zhao Tiantian (Zhao Tiantian, Lin Shuyu, Duan Yilin. Phononic crystal-like structure suppresses the lateral vibration of ultrasonic plastic welding tools [J]. Acta Physica Sinica, 2018, 67(22): 280-285.) used the band gap of phononic crystals to suppress the lateral vibration of large-sized two-dimensional long strip tool heads; Wang Sha (Wang Sha, Lin Shuyu, Duan Yilin. Large-sized ultrasonic plastic welding system based on two-dimensional phononic crystal structure [J]. Applied Acoustics, 2018, 37(05): 811-816.) used the band gap of phononic crystals to suppress the lateral vibration of large-sized cylindrical tool heads. .

[0004] Based on the above research, it can be seen that the commonly used control methods for the lateral vibration of the tool head include slotting, adding elastic components, opening fine slits, and secondary design. These methods can improve the output amplitude of the large-size tool head to a certain extent and control the lateral vibration of the tool head. However, the determination of the slot size, slot position, and number of slots mainly depends on the developer's practical experience and simulation calculations, and lacks an effective theoretical basis. Secondly, due to the influence of coupled vibration, the amplitude of the welding surface output is still small when the lateral vibration of the large-size tool head is controlled only by slotting and other methods. Therefore, researching and developing new methods and theories for suppressing the lateral vibration of the tool head, further improving the welding strength and welding accuracy of the large-size welding tool head, and improving the efficiency and quality of welding will better promote the engineering application of large-size tool heads.

[0005] Based on this, it is necessary to propose a large-sized ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a large-sized ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude in view of the deficiencies of the above-mentioned prior art. The method forms an air-metal three-dimensional near-periodic phononic crystal defect structure by respectively opening penetrating periodic air grooves on the front and back, left and right surfaces of the tool head, and opening air holes on the upper and lower surfaces, thereby suppressing the lateral vibration of the large-sized ultrasonic plastic welding tool head and improving the uniformity of the amplitude distribution. In combination with respectively opening a surface groove structure on the surface of the tool head, the sound wave is localized at the defect or transmitted along the defect, which greatly improves the output amplitude of the welding surface of the tool head, thereby improving the precision and quality of welding, and solving the problem that the existing large-sized tool head has severe lateral vibration and the amplitude is too small to affect the welding effect.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude, characterized in that the tool head is a metal cuboid, the length of the metal cuboid is a, the width is b, the height is c, and 150mm≤a≤280mm, 80mm≤b≤210mm, 100mm≤c≤230mm, and with reference to the three-dimensional coordinate system, the tool head is provided with m penetrating periodic first air grooves on the front and rear surfaces along the X-axis direction, i.e., the length direction, and the left and right surfaces along the Y-axis direction, i.e., the width direction. There are n penetrating periodic second air grooves on the top, and d rows × e columns of air holes are opened on the upper and lower surfaces along the Z-axis direction, i.e., the height direction, to form an air-metal three-dimensional nearly periodic phononic crystal defect structure. There are also f first grooves parallel to the center line of the tool head in the length direction, and g second grooves parallel to the center line of the tool head in the width direction on the upper surface of the tool head. There are i parallel and symmetrical third grooves on the front and rear surfaces of the tool head, respectively, and j parallel and symmetrical fourth grooves on the left and right surfaces of the tool head, respectively, to form a surface groove structure.

[0008] The above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that 1≤m≤8, 1≤n≤6, and the first air groove and the second air groove are rectangular structures, the height of the rectangular structure is h1, the width is w, and 30mm≤h1≤100mm, 1mm≤w≤12mm.

[0009] The above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that m=5, n=3, h1=66mm, w=6mm; on the front and rear surfaces of the tool head, the center line of the first air groove of the middle penetrating period coincides with the center line of the length direction of the tool head, and the other four first air grooves of the penetrating period are symmetrically distributed based on the middle penetrating period first air groove, and the distances between the corresponding centers and the center line of the length direction of the tool head are l1 and l2, respectively, and 20mm≤l1≤84mm, 6mm≤l2≤42mm; on the left and right surfaces of the tool head, the center of the second air groove of the middle penetrating period coincides with the center line of the width direction of the line tool head, and the other two second air grooves of the penetrating period are symmetrically distributed based on the middle second air groove of the penetrating period, and the distances between the centers and the center line of the width direction of the tool head are l3, and 6mm≤l3≤47mm.

[0010] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has a large amplitude is characterized in that l1=56mm, l2=30mm, and l3=29mm.

[0011] The above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that 1≤d≤7, 1≤e≤9, and the air hole is a cylindrical structure, the radius of the cylindrical structure is r1, the height is h3, and 1mm≤r1≤15mm, 10mm≤h3≤100mm.

[0012] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has large amplitude is characterized in that d=2, e=4, r1=4mm, h3=95mm, and the air holes on the upper and lower surfaces of the air holes in the tool head are symmetrical based on the center line of the length direction and the center line of the width direction of the tool head, and the distances between each center and the center line of the length direction of the tool head are respectively l 14 , l 15 , the distance between each center and the center line of the tool head in the width direction is l 16 , and 4mm≤l 14 ≤44mm, 10mm≤l 15 ≤88mm, 10mm≤l 16 ≤51mm.

[0013] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has large amplitude is characterized in that: 14 =42mm, l 15 =80mm, l 16 =20mm.

[0014] The above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that 2≤f≤10, 2≤g≤10, 2≤i≤8, 2≤j≤6, and the first groove, the second groove, the third groove, and the fourth groove are rectangular structures, the width of the rectangular structure is w1, the thickness is h4, the length of the first groove is the same as the width of the tool head, the length of the second groove is the same as the length of the tool head, and the lengths of the third groove and the fourth groove are both l a , and 0.5mm≤w1≤10mm, 0.5mm≤h4≤10mm, 20mm≤l a ≤180mm.

[0015] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has large amplitude is characterized in that f=6, g=4, i=6, j=4, w1=5mm, h4=1mm, l a =90mm; the six first grooves are symmetrical based on the center line of the tool head in the length direction, and the distances between the corresponding centers and the center line of the tool head in the length direction are l4, l5, and l6, and 3mm≤l4≤30mm, 6mm≤l5≤60mm, and 10mm≤l6≤87mm; the four second grooves are symmetrical based on the center line of the tool head in the width direction, and the distances between the corresponding centers and the center line of the tool head in the width direction are l 12 , l 13 , and 5mm≤l 12 ≤30mm, 10mm≤l 13 ≤50mm; the six third grooves are symmetrical based on the center line of the length direction of the tool head, and the distances between the corresponding centers and the center line of the width direction of the tool head are l7, l8, and l9, and 3mm≤l7≤30mm, 6mm≤l8≤60mm, and 10mm≤l9≤87mm; the four fourth grooves are symmetrical based on the center line of the width direction of the tool head, and the distances between the corresponding centers and the center line of the width direction of the tool head are l 10 , l 11 , and 3mm≤l 10 ≤20mm, 6mm≤l 11 ≤53mm.

[0016] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has large amplitude is characterized in that l4=27.5mm, l5=47.5mm, l6=67.5mm, l 12 =27.5mm, l 13 =37.5mm, l7=12.5mm, l8=39.5mm, l9=77.5mm, l 10 =12.5mm, l 11 =37.5mm.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. The present invention forms an air-metal three-dimensional near-periodic phononic crystal defect structure by opening penetrating periodic first air grooves on the front and rear surfaces of the tool head, opening penetrating periodic second air grooves on the left and right surfaces, and opening air holes on the upper and lower surfaces. The lateral band gap of the structure is used to suppress the lateral vibration of the large-sized ultrasonic plastic welding tool head, and the defect structure is used to adjust the mode field distribution and phase of the local mode, thereby improving the uniformity of the amplitude distribution of the welding surface of the welding tool head, avoiding local overflow or leakage of the weldment, and thus improving the accuracy and quality of welding.

[0019] 2. Grooves are respectively opened on the surface of the tool head of the present invention to form a surface groove structure, which localizes the sound waves at the defects or transmits them along the defects, and exerts the backscattering suppression characteristics to obtain extremely high energy transmission efficiency, thereby greatly improving the output amplitude of the welding surface of the tool head, promoting the melting of the weldment, and improving the welding strength.

[0020] 3. Different from the traditional "trial and error" design method of welding tool heads, which relies on the experience and intuition of designers for continuous testing and correction, resulting in low design efficiency and success rate and performance cannot be guaranteed, the present invention utilizes data analysis technology to perform data curve estimation analysis on experimental data through SPSS software, sets variables (structural parameters) and dependent variables (performance indicators such as f), selects a variety of curve models such as linear, quadratic, composite and cubic models for fitting, and establishes a performance prediction model for large-size welding tool heads, thereby improving design efficiency and quality and solving the problems of long development cycle and high cost in previous designs.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a large-size ultrasonic plastic welding tool head of the present invention.

[0023] Figure 2 The diagram is a schematic diagram of the structure and dimensions on the front and rear surfaces of a large-sized ultrasonic plastic welding tool head of the present invention.

[0024] Figure 3 It is a schematic diagram of the structure and dimensions on the left and right surfaces of the large-sized ultrasonic plastic welding tool head of the present invention.

[0025] Figure 4 The figure is a schematic diagram of the structure and dimensions on the upper surface of the large-sized ultrasonic plastic welding tool head of the present invention.

[0026] Figure 5This is an acceleration response curve diagram of the large-size ultrasonic plastic welding tool head of the present invention.

[0027] Figure 6 The figure is a schematic diagram of the structure of a large-sized ultrasonic plastic welding tool head that has not been optimized in the prior art.

[0028] Figure 7 This is a comparison diagram of the displacement amplitude distribution of the large-sized ultrasonic plastic welding tool head of the present invention and the large-sized ultrasonic plastic welding tool head that has not been optimized in the prior art.

[0029] Figure 8 This is a comparison chart of the predicted and measured values ​​of the resonant frequency of the large-size ultrasonic plastic welding tool head of the present invention.

[0030] Fig. 9 The figure is a comparison chart of the predicted value and measured value of the displacement amplitude of the welding radiation surface of the large-size ultrasonic plastic welding tool head of the present invention.

[0031] Fig.10 This is a comparison chart of the predicted value and measured value of the amplitude distribution uniformity of the welding radiation surface of the large-size ultrasonic plastic welding tool head of the present invention.

[0032] Fig.11 This is a displacement distribution diagram of the radiation surface of the large-size ultrasonic plastic welding tool head of the present invention.

[0033] Fig.12 This is a radiation surface displacement distribution diagram of a large-sized ultrasonic plastic welding tool head that has not been optimized in the prior art.

[0034] Description of Reference Numerals

[0035] 1—penetrating period first air slot; 2—penetrating period second air slot; 3—air hole;

[0036] 4—first groove; 5—second groove; 6—third groove;

[0037] 7—Fourth groove. DETAILED DESCRIPTION

[0038] Example 1

[0039] like Figure 1As shown, the large-size ultrasonic plastic welding tool head of the present embodiment is a metal cuboid, the length of the metal cuboid is a, the width is b, the height is c, and 150mm≤a≤280mm, 80mm≤b≤210mm, 100mm≤c≤230mm, with reference to the three-dimensional coordinate system, the tool head is provided with m penetrating periodic first air grooves 1 on the front and rear surfaces along the X-axis direction, i.e., the length direction, and n penetrating periodic second air grooves 2 on the left and right surfaces along the Y-axis direction, i.e., the width direction, and d rows × e columns of air holes 3 are provided on the upper and lower surfaces along the Z-axis direction, i.e., the height direction, to form an air-metal three-dimensional nearly periodic phononic crystal defect structure, and the upper surface of the tool head is also provided with f first grooves 4 parallel to the center line of the length direction of the tool head, and g second grooves 5 parallel to the center line of the width direction of the tool head, and i parallel symmetrical third grooves 6 are respectively provided on the front and rear surfaces of the tool head, and j parallel symmetrical fourth grooves 7 are respectively provided on the left and right surfaces of the tool head, to form a surface groove structure.

[0040] In actual ultrasonic plastic welding, in order to ensure that the amplitude and energy can be efficiently and stably transmitted and output, the welding tool head is required to have a uniform displacement amplitude distribution on its welding surface to achieve the requirements of welding process efficiency and reliability. However, for larger weldments, in order to improve welding efficiency, large-sized tool heads (tool heads with lateral dimensions greater than one-quarter of the longitudinal wave wavelength) are usually used. Such large-sized ultrasonic plastic tool heads are easily affected by lateral vibrations in the length or width direction during welding, resulting in uneven amplitude distribution on the welding surface of the tool head, which can cause local overflow or leakage of the weldment, seriously affecting the accuracy and quality of welding. To solve this problem, the present invention provides a first penetrating periodic air groove on the front and rear surfaces of the tool head, a second penetrating periodic air groove on the left and right surfaces, and air holes on the upper and lower surfaces to form an air-metal three-dimensional nearly periodic phononic crystal defect structure. The lateral band gap of the structure is used to suppress the lateral vibration of the large-sized ultrasonic plastic welding tool head. At the same time, the defect structure is used to adjust the mode field distribution and phase of the localized mode. The existence of the defect structure in the air-metal three-dimensional nearly periodic phononic crystal will lead to the appearance of defect states within its bandgap, triggering the Anderson localization effect of elastic waves, that is, the position of elastic waves within the bandgap is reduced. The distribution of displacement or pressure has good localization at the defect, and the sound pressure resonance amplification at this place can be achieved by adjusting the radius size, filling rate, rotation angle, material and other parameters of the scatterer at the defect to realize the regulation of the defect state frequency, localization degree, defect state mode and other properties. Different defect modes correspond to different mode field distributions and vibration phases, and the defect structure can be used to artificially regulate the mode field distribution and vibration phase at the defect, further improve the uniformity of the amplitude distribution on the welding surface of the welding tool head, solve the problem of local overflow or welding leakage caused by the uneven transmission of vibration energy caused by lateral vibration, and improve the welding accuracy and quality.

[0041] In addition, due to coupled vibration, the amplitude output by a large-sized welding tool head on the welding surface is generally small, and increasing the amplitude within a suitable range can improve welding strength, shorten welding time, and improve welding efficiency. Based on this, the present invention forms an air-metal three-dimensional near-periodic phononic crystal defect structure on the tool head, and forms a surface groove structure by respectively opening grooves on the upper surface, front and rear surfaces, and left and right surfaces of the tool head, so that the sound waves are localized at the defect or transmitted along the defect, and have a higher quality factor. The surface groove structure has a backscattering suppression characteristic, which can better support the unidirectional transmission of energy, and can obtain extremely high energy transmission efficiency, thereby greatly improving the output amplitude of the tool head welding surface, and effectively solving the problem of difficult melting of weldments and insufficient welding strength due to small amplitude.

[0042] More preferably, the tool head is made of aluminum; a=180 mm, b=106 mm, c=111 mm.

[0043] like Figure 2 As shown, the above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that 1≤m≤8, 1≤n≤6, and the first air groove 1 and the second air groove 2 are rectangular parallelepiped structures, the height of the rectangular parallelepiped structure is h1, the width is w, and 30mm≤h1≤100mm, 1mm≤w≤12mm. By controlling the number range of air grooves and the rectangular parallelepiped structure, it is avoided that too many or too few of them affect the performance of the tool head in suppressing lateral vibration.

[0044] like Figure 1 , Figure 2 and Figure 3 As shown, the above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that m=5, n=3, h1=66mm, w=6mm; on the front and rear surfaces of the tool head, the center line of the first air slot 1 of the penetrating period in the middle coincides with the center line of the length direction of the tool head, and the other four first air slots 1 of the penetrating period are symmetrically distributed based on the first air slot 1 of the penetrating period in the middle, and the distances between the corresponding centers and the center line of the length direction of the tool head are l1 and l2, respectively, and 20mm≤l1≤84mm, 6mm≤l2≤42mm; on the left and right surfaces of the tool head, the center of the second air slot 2 of the penetrating period in the middle coincides with the center line of the width direction of the line tool head, and the other two second air slots of the penetrating period 2 are symmetrically distributed based on the second air slot 2 of the penetrating period in the middle, and the distances between the centers and the center line of the width direction of the tool head are l3, and 6mm≤l3≤47mm. By controlling the position of each air slot and the center line to form a staggered structure, the performance of the tool head in suppressing lateral vibration is guaranteed.

[0045] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has a large amplitude is characterized in that l1=56mm, l2=30mm, and l3=29mm.

[0046] like Figure 1 and Figure 4 As shown, the above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that 1≤d≤7, 1≤e≤9, and the air hole 3 is a cylindrical structure, the radius of the cylindrical structure is r1, the height is h3, and 1mm≤r1≤15mm, 10mm≤h3≤100mm.

[0047] like Figure 1 and Figure 4As shown, the above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that d=2, e=4, r1=4mm, h3=95mm, and on the upper and lower surfaces of the air hole 3 in the tool head, the air holes 3 are symmetrical based on the center line of the length direction and the center line of the width direction of the tool head, and the distances between each center and the center line of the length direction of the tool head are respectively l 14 , l 15 , the distance between each center and the center line of the tool head in the width direction is l 16 , and 4mm≤l 14 ≤44mm, 10mm≤l 15 ≤88mm, 10mm≤l 16 ≤51mm. By controlling the position of each air hole and the center line to form a staggered structure, the tool head is guaranteed to suppress lateral vibration.

[0048] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has large amplitude is characterized in that: 14 =42mm, l 15 =80mm, l 16 =20mm.

[0049] like Figure 1 and Figure 2 As shown, the above-mentioned large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude is characterized in that 2≤f≤10, 2≤g≤10, 2≤i≤8, 2≤j≤6, and the first groove 4, the second groove 5, the third groove 6, and the fourth groove 7 are rectangular structures, the width of the rectangular structure is w1, the thickness is h4, the length of the first groove 4 is the same as the width of the tool head, the length of the second groove 5 is the same as the length of the tool head, and the lengths of the third groove 6 and the fourth groove 7 are both l a , and 0.5mm≤w1≤10mm, 0.5mm≤h4≤10mm, 20mm≤l a ≤180mm.

[0050] like Figure 1 and Figure 2 to Figure 4 As shown, the above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has large amplitude is characterized in that f=6, g=4, i=6, j=4, w1=5mm, h4=1mm, l a=90mm; the six first grooves 4 are symmetrical based on the center line of the length direction of the tool head, and the distances between the corresponding centers and the center line of the length direction of the tool head are l4, l5, and l6, and 3mm≤l4≤30mm, 6mm≤l5≤60mm, and 10mm≤l6≤87mm; the four second grooves 5 are symmetrical based on the center line of the width direction of the tool head, and the distances between the corresponding centers and the center line of the width direction of the tool head are l 12 , l 13 , and 5mm≤l 12 ≤30mm, 10mm≤l 13 ≤50mm; the six third grooves 6 are symmetrical based on the center line of the length direction of the tool head, and the distances between the corresponding centers and the center line of the width direction of the tool head are l7, l8, l9, and 3mm≤l7≤30mm, 6mm≤l8≤60mm, 10mm≤l9≤87mm; the four fourth grooves 7 are symmetrical based on the center line of the width direction of the tool head, and the distances between the corresponding centers and the center line of the width direction of the tool head are l 10 , l 11 , and 3mm≤l 10 ≤20mm, 6mm≤l 11 ≤53mm. By controlling the distribution of the grooves, especially the symmetrical distribution, it is helpful to improve the output amplitude of the welding surface of the tool head and ensure the large amplitude performance of the tool head; at the same time, no grooves are set on the lower surface of the tool head to keep the surface smooth and suitable for welding.

[0051] The above-mentioned large-size ultrasonic plastic welding tool head which can effectively suppress lateral vibration and has large amplitude is characterized in that l4=27.5mm, l5=47.5mm, l6=67.5mm, l 12 =27.5mm, l 13 =37.5mm, l7=12.5mm, l8=39.5mm, l9=77.5mm, l 10 =12.5mm, l 11 =37.5mm.

[0052] The large-size ultrasonic plastic welding tool head of the present invention was tested and the acceleration response curve of the tool head was calculated. The results are as follows: Figure 5 As shown. Figure 5 It can be seen that there is a vibration band gap in the X and Y directions around 20kHz ( Figure 5 The frequency range corresponding to the attenuation zone with a medium acceleration amplitude less than 10° is the vibration band gap of the original cell in the X and Y directions), so the tool head can suppress the lateral vibration in the X and Y directions, making the system vibration mode more single, and solving the problem of uneven transmission of vibration energy caused by lateral vibration.

[0053] The large-size ultrasonic plastic welding tool head of the present invention is compared with the large-size ultrasonic plastic welding tool head that is not optimized in the prior art (such as Figure 6 As described above, the displacement amplitude of the tool head (a metal cuboid) is tested and calculated using the simulation software Comsol and formulas (1) and (2).

[0054]

[0055] In formulas (1) and (2), U n is the uniformity of the displacement amplitude distribution of the welding surface, S n is the average displacement amplitude of the welding surface, n is the number of simulation data, S i is the displacement amplitude of a point on the welding surface, max (amplitude) is the maximum displacement amplitude on the welding surface, and min (amplitude) is the minimum displacement amplitude on the welding surface.

[0056] The average displacement amplitude output by the welding surface of the large-size ultrasonic plastic welding tool head that has not been optimized in the prior art is 0.00467 mm, and the uniformity of the displacement amplitude distribution of the welding surface is 0.0427%, while the average displacement amplitude output by the welding surface of the large-size ultrasonic plastic welding tool head of the present invention is 0.0271 mm, and the uniformity of the displacement amplitude distribution of the welding surface is 91.877%, that is, the average displacement amplitude output by the welding surface of the large-size ultrasonic plastic welding tool head of the present invention and the uniformity of the displacement amplitude distribution are 5.803 times and 2151.686 times of the former, respectively.

[0057] Figure 7 The displacement amplitude distribution comparison diagram of the large-sized ultrasonic plastic welding tool head of the present invention and the large-sized ultrasonic plastic welding tool head that is not optimized in the prior art is shown in FIG. 1 , wherein the red figure above is the tool head of the present invention, and the light blue figure is the tool head of the prior art. Figure 7 It can be seen that the tool head of the present invention not only significantly improves the uniformity of the displacement amplitude distribution of the welding surface, but also greatly improves the displacement amplitude, that is, the tool head has better welding accuracy and welding strength, effectively improving the welding quality and welding efficiency.

[0058] The present invention uses SPSS data analysis software to analyze the influence of structural parameters of surface grooves of a large-sized ultrasonic plastic welding tool head, structural parameters of cylindrical air holes and structural parameters of penetrating periodic rectangular air grooves on tool head performance indicators including longitudinal resonant frequency, displacement amplitude distribution uniformity and welding surface displacement amplitude, sets variables (structural parameters) and dependent variables (performance indicators such as f), selects multiple curve models such as linear, quadratic, composite and cubic models for fitting, establishes a performance prediction model for a large-sized welding tool head, and selects the best model according to data characteristics and goodness of fit indicators (such as R square value); finally, based on the displacement of the surface groove, the width w1 of the surface groove is established, and the longitudinal resonant frequency f, the displacement amplitude distribution uniformity S and the displacement amplitude distribution uniformity S are determined. n , welding surface displacement amplitude U n The prediction model is as follows:

[0059] f=A+B*w1+C*w1 2 +D*w1 3 (A, B, C, D are constants) (3)

[0060] In formula (3), A, B, C, and D are 20131.1423, 6.535, -0.423, and 0.0177, respectively.

[0061] S n =A+B*w1+C*w1 2 +D*w1 3 (A, B, C, D are constants) (4)

[0062] In formula (4), A, B, C, and D are 0.0172, 0.0000359, -0.0000345, and 0.00000365, respectively.

[0063] U n =A+B*w1+C*w1 2 +D*w1 3 (A, B, C, D are constants) (5)

[0064] In formula (5), A, B, C, and D are 0.912, 0.01295, -0.00459, 0.000379, respectively.

[0065] In order to verify the validity of the prediction model, SPSS data analysis software was used to compare the predicted values ​​with the measured values. Figure 8 to Figure 10 As shown. Figure 8 to Figure 10It can be seen that the relative error between the predicted value and the measured value of the resonant frequency of the tool head is within the range of ±1%, the relative error between the predicted value and the measured value of the displacement amplitude of the welding radiation surface of the tool head is within the range of ±3%, and the relative error between the predicted value and the measured value of the displacement amplitude uniformity of the welding radiation surface of the tool head is within the range of ±1%, indicating that the prediction model has achieved very good accuracy.

[0066] Fig.11 This is the displacement distribution diagram of the radiation surface of the large-size ultrasonic plastic welding tool head of the present invention, from Fig.11 It can be seen that the displacement amplitude distribution of the radiation surface of the large-size ultrasonic plastic welding tool head is more uniform, and the displacement amplitude is also greatly improved.

[0067] Fig.12 It is a large-size ultrasonic plastic welding tool head that is not optimized in the prior art ( Figure 6 ) of the radiation surface displacement distribution diagram, from Fig.12 It can be seen that, affected by the Poisson effect, the unoptimized large-size ultrasonic plastic welding tool head produces severe lateral vibrations along the X and Y directions, resulting in uneven displacement of the radiation surface.

[0068] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A large-size ultrasonic plastic welding tool head that can effectively suppress lateral vibration and has a large amplitude, characterized in that: The tool head is a metal cuboid, the length of the metal cuboid is a, the width is b, the height is c, and 150 mm ≤ a ≤ 280 mm, 80 mm ≤ b ≤ 210 mm, and 100 mm ≤ c ≤ 230 mm. With reference to a three-dimensional coordinate system, the tool head is provided with m penetrating periodic first air grooves (1) on the front and rear surfaces along the X-axis direction, i.e., the length direction, and n penetrating periodic second air grooves (2) on the left and right surfaces along the Y-axis direction, i.e., the width direction, and d rows × e columns of air holes (3) on the upper and lower surfaces along the Z-axis direction, i.e., the height direction, to form an air-metal three-dimensional nearly periodic phononic crystal defect structure. The upper surface of the tool head is also provided with f first grooves (4) parallel to the center line of the tool head in the length direction, and g second grooves (5) parallel to the center line of the tool head in the width direction, and i parallel symmetrical third grooves (6) are respectively provided on the front and rear surfaces of the tool head, and j parallel symmetrical fourth grooves (7) are respectively provided on the left and right surfaces of the tool head, to form a surface groove structure.

2. A large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 1, characterized in that: The 1≤m≤8, 1≤n≤6, and the first air slot (1) and the second air slot (2) are rectangular parallelepiped structures, the height of the rectangular parallelepiped structure is h1, the width is w, and 30mm≤h1≤100mm, 1mm≤w≤12mm.

3. A large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 2, characterized in that: Said m=5, n=3, h1=66mm, w=6mm; on the front and rear surfaces of the tool head, the center line of the first penetrating periodic air groove (1) located in the middle coincides with the center line of the tool head in the longitudinal direction, and the other four first penetrating periodic air grooves (1) are symmetrically distributed based on the first penetrating periodic air groove (1) in the middle, and the distances between the corresponding centers and the center line of the tool head in the longitudinal direction are l1 and l2, and 20mm≤l1≤84mm, 6mm≤l2≤42mm; on the left and right surfaces of the tool head, the center of the second penetrating periodic air groove (2) located in the middle coincides with the center line of the tool head in the width direction, and the other two second penetrating periodic air grooves (2) are symmetrically distributed based on the second penetrating periodic air groove (2) in the middle, and the distances between the corresponding centers and the center line of the tool head in the width direction are l3, and 6mm≤l3≤47mm.

4. A large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 3, characterized in that: l1=56mm, l2=30mm, l3=29mm.

5. The large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 1, characterized in that: The 1≤d≤7, 1≤e≤9, and the air hole (3) is a cylindrical structure, the radius of the cylindrical structure is r1, the height is h3, and 1mm≤r1≤15mm, 10mm≤h3≤100mm.

6. A large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 5, characterized in that: Said d=2, e=4, r1=4mm, h3=95mm, on the upper and lower surfaces of the air hole (3) in the tool head, the air hole (3) is symmetrical based on the center line of the length direction and the center line of the width direction of the tool head, and the distances between each center and the center line of the length direction of the tool head are l 14 , l 15 , the distance between each center and the center line of the tool head in the width direction is l 16 , and 4mm≤l 14 ≤44mm, 10mm≤l 15 ≤88mm, 10mm≤l 16 ≤51mm.

7. A large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 6, characterized in that: l 14 =42mm,l 15 =80mm,l 16 =20mm。 8. The large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 1, characterized in that: The first groove (4), the second groove (5), the third groove (6) and the fourth groove (7) are rectangular parallelepiped structures, the width of the rectangular parallelepiped structure is w1, the thickness is h4, the length of the first groove (4) is the same as the width of the tool head, the length of the second groove (5) is the same as the length of the tool head, and the lengths of the third groove (6) and the fourth groove (7) are both l a , and 0.5mm≤w1≤10mm, 0.5mm≤h4≤10mm, 20mm≤l a ≤180mm.

9. A large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 8, characterized in that: f=6, g=4, i=6, j=4, w1=5mm, h4=1mm, l a =90mm; the six first grooves (4) are symmetrical based on the center line of the tool head in the length direction, and the distances between the corresponding centers and the center line of the tool head in the length direction are l4, l5, and l6, respectively, and 3mm≤l4≤30mm, 6mm≤l5≤60mm, and 10mm≤l6≤87mm; the four second grooves (5) are symmetrical based on the center line of the tool head in the width direction, and the distances between the corresponding centers and the center line of the tool head in the width direction are l 12 , l 13 , and 5mm≤l 12 ≤30mm, 10mm≤l 13 ≤50mm; the six third grooves (6) are symmetrical based on the center line of the length direction of the tool head, and the distances between the corresponding centers and the center line of the width direction of the tool head are l7, l8, and l9 respectively, and 3mm≤l7≤30mm, 6mm≤l8≤60mm, and 10mm≤l9≤87mm; the four fourth grooves (7) are symmetrical based on the center line of the width direction of the tool head, and the distances between the corresponding centers and the center line of the width direction of the tool head are l 10 , l 11 , and 3mm≤l 10 ≤20mm, 6mm≤l 11 ≤53mm.

10. A large-size ultrasonic plastic welding tool head capable of effectively suppressing lateral vibration and having a large amplitude according to claim 9, characterized in that: <h2 style=";text-align:left;direction:ltr">l4 = 27.5mm, l5 = 47.5mm, l6 = 67.5mm, l<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> =27.5mm,l<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> =37.5mm,l7=12.5mm,l8=39.5mm,l9=77.5mm,l<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> =12.5mm,l<h2 style=";text-align:left;direction:ltr"> 11 <h2 style=";text-align:left;direction:ltr"> <37.5mm.

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