Ultrasonic torque welding welding head

Abstract

An ultrasonic torque welding horn includes a welding surface, a plurality of protruding welding teeth are arranged on the welding surface, and the tops of the welding teeth are configured as an effective working area of ​​the ultrasonic torque welding horn, wherein the welding teeth are radially distributed around the torsion center, the circumferential spacing between the tops of the welding teeth gradually increases from the inside to the outside, and the circumferential effective working length of the welding teeth gradually increases from the inside to the outside. The ultrasonic torque welding horn can promote uniform energy distribution in the welding area, avoid burrs and broken wires, improve welding quality, improve welding stability and consistency, and at the same time extend the service life of the welding horn.

Description

Technical Field

[0001] The utility model belongs to the field of ultrasonic welding, and in particular relates to an ultrasonic torque welding head. Background Art

[0002] Ultrasonic welding has the advantages of low energy consumption, high efficiency, and no sparks. It has been widely used in the fields of lithium batteries and electronic manufacturing. In conventional ultrasonic welding, the welding head adopts a linear vibration mode, with a large displacement along the vibration direction and limited precision. Ultrasonic torque welding adopts the form of circumferential torsional vibration of the welding head. The welding head as a whole does not undergo linear displacement, has higher positioning accuracy, and is suitable for annular structure welding and application scenarios where the welding point needs to be accurately positioned. The welding surface of the ultrasonic welding head is usually provided with a matrix of protruding welding teeth to increase the friction between the welding head and the metal material. However, during the circumferential torsional vibration of the torque welding welding head, the amplitude increases with the distance from the relative torsion center, resulting in uneven energy distribution on the welding surface. The metal material in the peripheral edge area is easily squeezed out of the welding tooth groove under high pressure and high frequency vibration, forming post-weld burrs, affecting the welding quality and even causing the risk of product scrapping. Therefore, providing an ultrasonic torque welding welding head that can prevent the generation of welding burrs has positive significance for improving the quality of torque welding, increasing the service life of the welding head, and reducing production costs. Utility Model Content

[0003] The utility model aims to provide an ultrasonic torque welding head, which can prevent the generation of welding burrs in the welding point area.

[0004] According to an embodiment of the utility model, an ultrasonic torque welding horn is provided, which comprises a welding surface, on which a plurality of raised welding teeth are arranged, and the tops of the welding teeth are configured as the effective working area of ​​the ultrasonic torque welding horn, and is characterized in that the welding teeth are radially distributed around the torsion center of the ultrasonic torque welding horn, wherein the circumferential spacing between the tops of the welding teeth gradually increases from the inside to the outside, and the circumferential effective working length of the welding teeth gradually increases from the inside to the outside.

[0005] The ultrasonic torque welding horn has a small circumferential gap in the area close to the torsion center, and a large circumferential spacing of the welding teeth at a position far from the torsion center, which can increase the energy density of the welding surface close to the center area, reduce the energy density on the welding surface of the peripheral area, reduce the unevenness of energy distribution, and avoid melting of materials due to higher amplitude in the peripheral area; at the same time, the spacing of the welding teeth in the peripheral area is larger, so that the spacing area between the welding teeth can accommodate softened extruded materials, avoid the material being extruded from the welding area and forming burrs, and improve the welding quality. Furthermore, the peripheral welding teeth have a longer circumferential effective working length, so that the load distribution of the welding teeth in the central area and the peripheral area is more uniform, avoiding the wear of the welding teeth in the peripheral area due to higher amplitude, extending the service life of the welding horn, and improving the stability and consistency of welding quality.

[0006] Furthermore, in some embodiments, the welding surface is provided with a circular central area, and the welding teeth are configured as ridges extending radially outward from the central area along the welding surface.

[0007] Furthermore, in some embodiments, the effective working area of ​​the convex ridge is configured as a triangular plane, the triangular plane gradually expands outward from the central area, and the triangular planes of all the convex ridges are located in the same plane.

[0008] Furthermore, in some embodiments, a plurality of pyramid-shaped bosses are provided on the convex ridge, the effective working area is configured as the top surface of the pyramid-shaped bosses, and the top surfaces of all the pyramid-shaped bosses are located in the same plane.

[0009] Furthermore, in some embodiments, the ridge has a proximal end close to the central area and a distal end away from the central area, and the proximal end is located on the circumference of the central area boundary, and the position where the distal end terminates forms the outer circle of the welding surface; wherein, the position where the distal end terminates forms the outer circle of the welding surface; wherein, the corresponding arc length of the ridge at the bottom of the proximal end is 1 / 20-1 / 2 of the circumference of the central area, and the arc length of the ridge at the bottom of the distal end is 1 / 20-1 / 2 of the circumference of the outer circle.

[0010] Furthermore, in some embodiments, the cross-section of the ridge perpendicular to the radial direction of the welding surface is configured as an isosceles triangle or an isosceles trapezoid.

[0011] Furthermore, in some embodiments, the welding teeth are configured as a plurality of welding tooth groups, each of the welding tooth groups includes a plurality of welding tooth monomers radially arranged along the welding surface, the welding tooth monomers are arranged as a plurality of concentric circles around the torsion center, and the welding tooth monomers in each welding tooth group are arranged on each of the concentric circles, and the arrangement is the same as that of the welding tooth monomers on the same concentric circle.

[0012] Furthermore, in some embodiments, the welding tooth unit is configured as a circular boss.

[0013] Furthermore, in some embodiments, the welding tooth unit is configured as a spherical protrusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of an ultrasonic torque welding head in one embodiment;

[0015] Figure 2 This is a schematic diagram of the welding surface structure of an ultrasonic torque welding head in one embodiment;

[0016] Figure 3 It is a schematic diagram of the structure of an ultrasonic torque welding head in another embodiment;

[0017] Figure 4 It is a schematic diagram of the welding surface structure of an ultrasonic torque welding head in another embodiment;

[0018] Figure 5 It is a schematic diagram of the structure of an ultrasonic torque welding head in another embodiment;

[0019] Figure 6 Schematic diagram of the structure of an ultrasonic torque welding head in yet another embodiment.

[0020] The purpose of the above drawings is to further explain the utility model in detail so that those skilled in the art can understand the technical concept of the utility model, but it is not intended to limit the utility model. For the sake of simplicity, the above drawings only schematically illustrate the structure related to the technical features of the utility model, and do not strictly draw the complete structure or all details according to the actual proportion. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The phrase appearing in various locations in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments herein may be combined with other embodiments without causing structural conflicts.

[0023] In the description of this article, unless otherwise clearly specified and limited, the technical terms "install", "connect", "connect", etc. should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0024] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to have a specific orientation, be installed or operate in a specific orientation, and should not be construed as a limitation on the embodiments in this document.

[0025] In the description of this article, the terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order or primary and secondary relationship of the described technical features. In the description of this article, the meaning of "plurality" is at least two.

[0026] Ultrasonic metal welding machines use transducers to convert electrical energy into high-frequency mechanical vibrations. Under pressure, high-frequency mechanical waves are transmitted to the metal materials to be welded through the welding head, causing local high-frequency friction between the two metal materials to be welded, thereby connecting them together. In order to increase the friction between the welding head and the material and ensure that the welding head can drive the material to be welded to vibrate, a welding tooth structure arranged in a matrix form is usually provided on the working surface of the welding head, that is, the welding surface. For conventional ultrasonic linear welding processes, the welding head performs linear reciprocating vibrations as a whole, and the matrix-shaped welding teeth can effectively meet its technical needs and achieve the purpose of improving welding quality. However, the displacement of the welding head of linear welding in the vibration direction is large, the positioning accuracy is low, and it will also cause overall pulling of the material. In application scenarios where the working space is limited or the welding accuracy requirements are high, the application of linear welding is greatly limited. Ultrasonic torque welding achieves welding by making the welding head vibrate at high frequency around the torsion center. Macroscopically, there is almost no linear displacement of the welding head, and the positioning accuracy is higher. It is suitable for circular, annular and application scenarios with high requirements for welding accuracy. However, the amplitude of different areas on the welding surface of the torque welding horn is proportional to its distance from the torsion center, which results in a small amplitude and less energy transfer in the central area of ​​the welding surface, while a large amplitude and more energy transfer in the peripheral area. The material in the peripheral area is prone to rapid temperature rise and softening or even close to melting, and the softened material is squeezed out of the welding area and easily forms burrs and broken wires, which seriously affect the welding quality and may even cause the workpiece to be scrapped. Furthermore, since the amplitude of the peripheral area of ​​the welding horn is larger, it is more prone to wear, microcracks or chipping, which in turn affects the life of the welding horn. In some application scenarios, the traditional matrix welding teeth will also have the problem of sticking, which is not conducive to fast-beat automated continuous production.

[0027] In order to solve the above problems, an embodiment of the utility model provides an ultrasonic torque welding horn. The welding surface of the horn is provided with welding teeth radially around the torsion center, the circumferential spacing between the tops of the welding teeth gradually increases from the inside to the outside, and the circumferential effective working length also gradually increases from the inside to the outside. Specifically, the top of the welding tooth, that is, the end away from the welding surface of the horn, is the effective working area of ​​the welding tooth. During the welding process, the effective working area contacts the material to transfer energy. The circumferential effective working length of the welding tooth is the arc length of the effective working area of ​​the welding tooth within a circle around the torsion center of a given radius. The effective working length of a single welding tooth at a position close to the torsion center is less than the effective working length of a single welding tooth at a position away from the torsion center.

[0028] In some embodiments, Figure 1 As shown, the welding surface of the welding head is provided with a circular central area 1, in which no welding teeth are provided, and the welding teeth 3 are provided as radially distributed ridges extending radially outward from the central area along the welding surface. Figure 2 , an effective working area 31 is set on the top of the welding tooth 3, and the effective working area 31 is a triangular plane. The triangle formed by the effective working area 31 gradually expands from the central area 1 to the outside. The effective working areas 31 on each welding tooth 3 are all located in the same plane. When the welding head contacts the material, each effective working area 31 forms a uniform contact with the material. The two hypotenuses of the welding tooth 3 are respectively at an angle of 45° relative to the welding surface of the welding head, so that the cross-section of the welding tooth 3 close to the central area 1 (perpendicular to the radial direction of the welding surface) is an isosceles right triangle, and the cross-section shape at other positions is an isosceles trapezoid with a base angle of 45°. One end of the welding tooth 3 extends outward from the outer periphery of the central area 1, and the terminal position of the other end forms an outer circle 2. In a preferred embodiment, the corresponding arc length of the bottom of the welding tooth 3 on the outer periphery of the central area 1 (i.e., the arc length spanned by the bottom of the welding tooth) is 1 / 8 of the circumference of the central area, and the corresponding arc length of the bottom of the welding tooth 3 on the outer circle 2 is 1 / 16 of the circumference of the outer circle. In other embodiments, the corresponding arc length of the bottom of the welding tooth 3 on the outer periphery of the central area 1 can be set to 1 / 20-1 / 2 of the circumference of the central area 1, and the corresponding arc length of the bottom on the outer ring 2 can be set to 1 / 20-1 / 2 of the circumference of the outer ring 2.

[0029] Since the welding teeth 3 near the central area 1 have a higher circumferential density (the spacing between the welding teeth 3 is smaller, and the effective working area 31 of the welding teeth 3 on the circumference occupies a higher proportion), the uniformity of energy transfer between the center and the outer periphery of the welding surface can be improved during torque welding. At the same time, since the spacing between the outer welding teeth 3 is larger, if the softened material is deformed, it can be accommodated in the spacing of the welding teeth 3. On the one hand, it avoids the formation of burrs in the material base welding area, and on the other hand, it can reduce the pressure of the softened material on the welding teeth 3 and extend the life of the welding head. Furthermore, the effective working length of the welding teeth 3 on the outer side is greater than that on the inner side, which reduces the load borne by the welding teeth 3 per unit effective working length, and can also extend the service life of the welding head and improve the welding quality and stability. In different embodiments, the edge of the welding tooth 3 can also have a flat edge or chamfer.

[0030] In another preferred embodiment, Figure 3 As shown, the welding tooth 4 is a convex ridge extending from the central area 1 to the outer ring 2. The welding tooth 4 is further provided with pyramid-shaped bosses 41 arranged radially along the welding surface. The top surfaces 42 of these pyramid-shaped bosses 41 are located in the same plane, forming an effective working area of ​​the welding tooth 4. On any cross section perpendicular to the radial direction of the welding surface, the two oblique sides of the welding tooth 4 also form an isosceles trapezoid with a bottom angle of 45°. The bottom width of the welding tooth 4 on the outer periphery of the central area 1 is 1 / 5 of the perimeter of the central area, and the bottom width of the welding tooth 4 on the outer ring 2 is 1 / 20 of the perimeter of the outer ring.

[0031] In some embodiments, the radial convex ridge-shaped welding teeth can also be replaced by multiple groups of welding tooth monomers arranged radially along the welding surface, and these welding tooth monomers are arranged in multiple concentric circles around the torsion center of the welding head, and each concentric circle is arranged with a welding tooth monomer in each welding tooth group. The welding tooth monomers located on the same concentric circle are the same.

[0032] In another preferred embodiment, Figure 5 As shown, the welding teeth 5 are circular bosses, and multiple circular bosses are arranged in a straight line along the radial direction of the welding surface to form welding tooth groups, and each welding tooth group is arranged radially around the center of the welding surface. The top surface of each welding tooth 5 is located in the same plane, forming an effective working area of ​​the welding tooth 5. In different embodiments, the welding tooth 5 can be a cylindrical boss or a truncated cone. In some embodiments, the top surface of each welding tooth 5 can also have a certain drop.

[0033] In another preferred embodiment, Figure 6As shown, the welding teeth 6 are spherical protrusions, and multiple spherical protrusions are arranged in a straight line along the radial direction of the welding surface to form welding tooth groups, and each welding tooth group is arranged radially around the center of the welding surface. The tops of each welding tooth 6 are tangent to the same plane. Considering the elasticity of the welding teeth 6 and the material to be welded, the part where the top of the welding teeth 6 contacts the material during welding is the effective working area. In some embodiments, there may also be a certain drop at the top of each welding tooth 6.

[0034] For welding heads with single welding teeth, the circumferential spacing of the welding teeth is determined by the length of the concentric circle passing through the center of the welding teeth falling between the welding teeth, and the circumferential effective working length is the length of the concentric circle passing through the center of the welding teeth within the effective working area. Figure 6 The welding head shown can determine the area where the spherical welding tooth 6 contacts the material to be welded according to the amount of downward pressure during the torque welding process, and the circular plane surrounded by the boundary of this contact area can be equivalent to the effective working area. In other embodiments, the welding tooth monomer can also adopt a boss with an axial cross section in the form of a square, triangle or other polygon, and the geometric center of the axial cross section of the welding tooth monomer is used as the center of the welding tooth monomer.

[0035] In different embodiments, the welding surface of the torque welding horn can be set as a planar structure or a non-planar structure with a central protrusion. In some embodiments, the non-planar structure with a central protrusion makes the height of the welding teeth near the center smaller and the height of the welding teeth on the outer periphery larger, so that a larger space is formed between the effective working area of ​​the welding teeth on the outer periphery and the welding surface, and a larger volume of deformed material can be accommodated during the welding process. However, regardless of whether a planar structure or a non-planar structure is adopted, the effective working areas of all welding teeth should be in the same plane to ensure that the welding head is in uniform contact with the material to be welded during the welding process.

[0036] It should be understood that since torque welding uses the form of driving the welding head to perform circumferential reciprocating torsional vibration, whether using prismatically protruding welding teeth or a welding tooth group composed of single welding teeth, the shape of the radial cross-section perpendicular to the welding surface should be an axisymmetric structure to ensure that the force on both sides of the welding teeth along the vibration direction during the torsional vibration of the welding head is uniform.

[0037] The ultrasonic torque welding horn provided in the above-mentioned embodiment can solve the problems of burrs and broken wires caused by uneven energy transfer generated by traditional matrix welding teeth during torque welding, increase the service life of the welding horn, and improve welding stability and consistency. The lower circumferential density of the welding teeth on the outside reduces energy transfer and inhibits excessive temperature rise and softening of the material on the one hand, and provides space for material deformation on the other hand, which can prevent the material from being squeezed out of the welding area to form burrs or broken wires. The outer welding teeth have a longer circumferential effective working length, which reduces the load borne by the outer welding teeth, can reduce welding tooth wear, and avoid microcracks or chipping.

[0038] The purpose of the above embodiments is to further explain the present invention in detail in conjunction with the accompanying drawings so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, the optimization or equivalent replacement of the structure of the parts involved, and the combination of the implementation methods in different embodiments without conflict of structure and principle, all fall within the protection scope of the present invention.

Claims

1. An ultrasonic torque welding horn, comprising a welding surface, on which a plurality of protruding welding teeth are arranged, and the tops of the welding teeth are configured as the effective working area of ​​the ultrasonic torque welding horn, characterized in that: The welding teeth are radially distributed around the torsion center of the ultrasonic torque welding horn, wherein the circumferential spacing between the tops of the welding teeth gradually increases from the inside to the outside, and the circumferential effective working length of the welding teeth gradually increases from the inside to the outside.

2. The ultrasonic torque welding horn according to claim 1, characterized in that: The welding surface is provided with a circular central area, and the welding teeth are configured as convex ridges extending radially outward from the central area along the welding surface.

3. The ultrasonic torque welding horn according to claim 2, characterized in that: The effective working area of ​​the convex edge is configured as a triangular plane, the triangular plane gradually expands outward from the central area, and the triangular planes of all the convex edges are located in the same plane.

4. The ultrasonic torque welding horn according to claim 2, characterized in that: A plurality of pyramid-shaped bosses are arranged on the convex ridge, the effective working area is configured as the top surface of the pyramid-shaped bosses, and the top surfaces of all the pyramid-shaped bosses are located in the same plane.

5. The ultrasonic torque welding horn according to claim 2, 3 or 4, characterized in that: The ridge has a proximal end close to the central area and a distal end away from the central area, the proximal end is located on the circumference of the central area boundary, and the distal end terminates at a position forming an outer circle of the welding surface; wherein, the corresponding arc length of the ridge at the bottom of the proximal end is 1 / 20-1 / 2 of the circumference of the central area, and the arc length of the ridge at the bottom of the distal end is 1 / 20-1 / 2 of the circumference of the outer circle.

6. The ultrasonic torque welding horn according to claim 2, 3 or 4, characterized in that: The cross section of the convex ridge perpendicular to the radial direction of the welding surface is configured as an isosceles triangle or an isosceles trapezoid.

7. The ultrasonic torque welding horn according to claim 1, characterized in that: The welding teeth are configured as a plurality of welding tooth groups, each of the welding tooth groups includes a plurality of welding tooth monomers radially arranged along the welding surface, the welding tooth monomers are arranged as a plurality of concentric circles around the torsion center, and the welding tooth monomers in each welding tooth group are arranged on each of the concentric circles, and the arrangement is the same as that of the welding tooth monomers on the same concentric circle.

8. The ultrasonic torque welding horn according to claim 7, characterized in that: The welding tooth unit is configured as a circular boss.

9. The ultrasonic torque welding horn according to claim 7, characterized in that: The welding tooth unit is configured as a spherical protrusion.

Images