Ultrasonic welding head and ultrasonic welding device

Abstract

The utility model provides an ultrasonic welding head and an ultrasonic welding device, and the ultrasonic welding head comprises a body which is provided with a first contact surface, and the first contact surface comprises a welding surface and a connecting surface surrounding the circumferential direction of the welding surface; the welding teeth are used for welding a to-be-welded area of the tab and are convexly arranged on the welding surface along a first direction; the edge pressing part is arranged in the circumferential direction of the welding teeth in a surrounding mode, the edge pressing part comprises the connecting face, the connecting face forms an edge pressing face of the edge pressing part, the edge pressing face is used for abutting against a non-welding area of the tab, and the height of the edge pressing part in the first direction is smaller than that of the welding teeth in the first direction; wherein an included angle is formed between the edge pressing surface and the welding surface. According to the technical scheme of the utility model, the technical problem that the tab foil on the surface layer is shattered when the tab foil is welded by adopting ultrasonic waves can be solved.

Description

Technical Field

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

[0002] During lithium battery production, multiple layers of tab foil are welded to flexible connectors using ultrasonic welding. During ultrasonic welding, the ultrasonic welding head presses directly onto the multiple layers of tab foil. Because the surface of the multiple layers of tab foil is loose, the downward pressure of the welding head causes the foil to dent in the weld area and warp at the edges of the weld area. The ultrasonic waves are transmitted to the foil surface, causing it to vibrate passively at high frequencies. This can easily cause the outermost tab foil to crack, damaging the tab structure and reducing the yield rate after welding the tab to the flexible connector. Utility Model Content

[0003] The embodiments of the present utility model provide an ultrasonic welding head and an ultrasonic welding device, which can improve the technical problem that the surface tab foil is shattered when the tab foil is welded by ultrasonic welding.

[0004] In the first aspect, an embodiment of the present invention provides an ultrasonic welding head, which includes: a main body, having a first contact surface, the first contact surface including a welding surface and a connecting surface arranged circumferentially around the welding surface; a welding tooth, used for welding the area to be welded of the tab, and convexly arranged on the welding surface along the first direction; a pressure edge portion, arranged circumferentially around the welding tooth, the pressure edge portion including the connecting surface, the connecting surface forming the pressure edge surface of the pressure edge portion, the pressure edge surface being used to abut the non-welding area of ​​the tab, the height of the pressure edge portion in the first direction being smaller than the height of the welding tooth in the first direction; wherein, the pressure edge surface and the welding surface have an angle.

[0005] In one embodiment, the area of ​​the welding surface is S1, the sum of the areas of the edge holding portion and the welding surface is S2, and 0.36≤S1:S2≤0.71.

[0006] In one embodiment, the edge pressing portion includes a first edge pressing sub-portion extending along the second direction and a second edge pressing sub-portion extending along the third direction. The first direction, the second direction and the third direction are perpendicular to each other. The extension length of the first edge pressing sub-portion in the third direction is L1, and the extension length of the second edge pressing sub-portion in the second direction is L2, and L1=L2.

[0007] In one embodiment, 0.5 mm ≤ L1 ≤ 3 mm, and 0.5 mm ≤ L2 ≤ 3 mm.

[0008] In one embodiment, the surface of the edge pressing portion facing the tab is an arc-shaped surface, and the protruding direction of the arc-shaped surface is the same as the protruding direction of the welding tooth.

[0009] In one embodiment, the angle between the edge holding portion and the plane where the welding surface is located is α, and 1°≤α≤20°.

[0010] In one embodiment, a rounded corner structure is provided on a side of the edge holding portion away from the welding surface, and the radius of the rounded corner structure is R, where 0.5 mm ≤ R ≤ 3 mm.

[0011] In one embodiment, the welding tooth comprises a hemispherical structure or a conical structure.

[0012] In one embodiment, the ultrasonic horn includes a plurality of welding teeth, and the plurality of welding teeth are arrayed on the welding surface.

[0013] In a second aspect, an embodiment of the present invention provides an ultrasonic welding device, which includes the above-mentioned ultrasonic welding head.

[0014] By applying the technical solution of the present invention, a pressure edge portion is provided around the circumference of the welding surface, and the height of the pressure edge portion in the first direction is smaller than the height of the welding tooth in the first direction. With this arrangement, the welding head can suppress the deformation of the foil in the non-welding area during welding through the pressure edge portion with a certain angle at the edge of the welding surface, thereby reducing the stress concentration of the tab structure, thereby reducing the probability of the foil in the non-welding area being compressed and deformed and cracked under ultrasonic vibration, thereby ensuring the yield rate after welding the tab and the soft connecting sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 This is a three-dimensional schematic diagram of an ultrasonic welding head provided in an embodiment of the present utility model;

[0017] Figure 2 This is a three-dimensional schematic diagram of the ultrasonic welding head provided by an embodiment of the present utility model from another perspective;

[0018] Figure 3 This is a schematic top view of an ultrasonic welding head provided in an embodiment of the present utility model;

[0019] Figure 4 This is a side view of the ultrasonic welding head provided by an embodiment of the present utility model along the third direction;

[0020] Figure 5 It is a side view schematic diagram of the ultrasonic welding head provided by an embodiment of the present utility model along the second direction.

[0021] The above drawings include the following reference numerals:

[0022] 10. Main body; 11. Welding surface;

[0023] 20. Welding teeth;

[0024] 30. Edge pressing portion; 31. First edge pressing sub-portion; 32. Second edge pressing sub-portion;

[0025] 40. Rounded corner structure;

[0026] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0028] like Figures 1 to 5 As shown, in the first aspect, an embodiment of the present invention provides an ultrasonic welding head, which includes: a main body 10, having a first contact surface, the first contact surface including a welding surface 11 and a connecting surface arranged circumferentially on the welding surface 11; a welding tooth 20, used for welding the area to be welded of the tab, and convexly arranged on the welding surface 11 along the first direction; a pressure edge portion 30, arranged circumferentially on the main body 10, the pressure edge portion 30 is arranged circumferentially on the welding tooth 20, the pressure edge portion 30 includes a connecting surface, the connecting surface forms a pressure edge surface of the pressure edge portion 30, the pressure edge surface is arranged circumferentially on the welding surface 11, the pressure edge surface is used to abut the non-welding area of ​​the tab, and the height of the pressure edge portion 30 in the first direction is less than the height of the welding tooth 20 in the first direction; wherein, the pressure edge surface and the welding surface 11 have an angle.

[0029] By applying the technical solution of the present invention, a pressure edge portion 30 is provided around the circumference of the welding surface 11, and the height of the pressure edge portion 30 in the first direction is less than the height of the welding tooth 20 in the first direction. In this way, the welding head can suppress the deformation of the foil in the non-welding area during welding through the pressure edge portion 30 with a certain angle at the edge of the welding surface 11, thereby reducing the stress concentration of the tab structure, thereby reducing the probability of the foil in the non-welding area being compressed and deformed and cracked under ultrasonic vibration, thereby ensuring the yield rate after welding the tab and the soft connecting sheet.

[0030] During welding, the welding surface 11 can face the tab, and the welding teeth 20 can act on the tab, so that the edge pressing portion 30 can be in close contact with the non-welding area, preventing the risk of vibration cracking of the multi-layer tab foil.

[0031] In the present application, the welding surface 11 is specifically a planar structure, which is arranged so as to improve the stability of the welding teeth 20 when in contact with the tab, thereby ensuring the stability of welding.

[0032] In this application, X is the first direction, Y is the second direction, and Z is the third direction.

[0033] Furthermore, the area of ​​the welding surface 11 is S1, the sum of the areas of the edge holding portion 30 and the welding surface 11 is S2, and 0.36≤S1:S2≤0.71. When S1:S2>0.71, the ratio of the area of ​​the welding surface 11 to the sum of the areas of the edge holding portion 30 and the welding surface 11 is too large, which means that the area of ​​the welding surface 11 is too large. Since the area on one side of the main body 10 is a fixed value, the area of ​​the edge holding portion 30 will be reduced, which will reduce the contact area between the edge holding portion 30 and the non-welding area of ​​the tab, thereby failing to ensure effective clamping of the edge holding portion 30 on the non-welding area of ​​the tab, and failing to reduce the probability of the foil being compressed and deformed and cracked under ultrasonic vibration. When S1:S2<0.36, the ratio of the area of ​​the welding surface 11 to the sum of the areas of the edge holding portion 30 and the welding surface 11 is too large, which means that the area of ​​the welding surface 11 is too small. Since the area on one side of the main body 10 is a fixed value, the area of ​​the welding surface 11 of the welding tooth 20 and the area to be welded is reduced, which will reduce the welding efficiency. Therefore, setting 0.36≤S1:S2≤0.71 not only helps ensure that the edge holder 30 effectively presses the non-welding area of ​​the tab, reducing the probability of the foil being deformed by compression and cracking under ultrasonic vibration, but also ensures the welding surface area 11 between the welding teeth 20 and the area to be welded, thereby improving welding efficiency. Optionally, S1:S2 can be set to values ​​such as 0.36, 0.5, or 0.71. The specific setting should be selected according to the operating environment of the ultrasonic welding head and is not specifically limited here.

[0034] Specifically, the bead holding portion 30 includes a first bead holding sub-portion 31 extending along the second direction and a second bead holding sub-portion 32 extending along the third direction. The first direction, the second direction, and the third direction are perpendicular to each other. The first bead holding sub-portion 31 extends along the third direction by a length L1, and the second bead holding sub-portion 32 extends along the second direction by a length L2, where L1 = L2. This arrangement ensures that the widths of the first bead holding sub-portion 31 and the second bead holding sub-portion 32 are equal, which not only facilitates and reduces the difficulty of machining the structure, but also improves the structural consistency of the bead holding portion 30, thereby enhancing the structural stability of the bead holding portion 30.

[0035] Furthermore, 0.5mm≤L1≤3mm, 0.5mm≤L2≤3mm. When L1>3mm, the extension length of the first edge clamping sub-portion 31 in the third direction is too large, which will cause the extension length of the first edge clamping sub-portion 31 in the third direction to occupy too much space. Since the area of ​​one side of the main body 10 is a fixed value, the area of ​​the welding surface 11 will be too small, reducing the welding surface 11 area of ​​the welding teeth 20 and the area to be welded, thereby reducing the welding efficiency. When L1<0.5mm, the extension length of the first edge clamping sub-portion 31 in the third direction is too small. Since the area of ​​one side of the main body 10 is a fixed value, the area of ​​the edge clamping portion 30 will be reduced, which will reduce the contact area between the edge clamping portion 30 and the non-welding area of ​​the tab, thereby failing to ensure effective compression of the edge clamping portion 30 on the non-welding area of ​​the tab, and failing to reduce the probability of the foil being compressed and deformed under ultrasonic vibration and cracking. Therefore, setting 0.5mm≤L1≤3mm not only helps ensure that the edge clamping portion 30 effectively presses the non-welding area of ​​the tab, reducing the probability of the foil being deformed by compression and cracking under ultrasonic vibration, but also ensures the welding surface area 11 between the welding teeth 20 and the area to be welded, thereby improving welding efficiency. Optionally, L1 can be set to a value such as 0.5mm, 1.5mm, or 3mm. The specific setting should be selected based on the use environment of the first edge clamping sub-portion 31 and is not specifically limited here.

[0036] When L2>3mm, the extension length of the second edge clamping sub-portion 32 in the third direction is too large, which will cause the extension length of the second edge clamping sub-portion 32 in the third direction to occupy too much space. Since the area of ​​one side of the main body 10 is a fixed value, the area of ​​the welding surface 11 will be too small, reducing the welding surface area 11 of the welding tooth 20 and the area to be welded, thereby reducing the welding efficiency. When L2<0.5mm, the extension length of the second edge clamping sub-portion 32 in the third direction is too small. Since the area of ​​one side of the main body 10 is a fixed value, the area of ​​the edge clamping portion 30 will be reduced, which will reduce the contact area between the edge clamping portion 30 and the non-welding area of ​​the tab, thereby failing to ensure effective pressing of the edge clamping portion 30 on the non-welding area of ​​the tab, and failing to reduce the probability of the foil being compressed and deformed under ultrasonic vibration and cracking. Therefore, setting 0.5mm≤L2≤3mm not only helps ensure that the edge clamping portion 30 effectively presses the non-welding area of ​​the tab, reducing the probability of the foil being deformed by compression and cracking under ultrasonic vibration, but also ensures the welding surface area 11 between the welding teeth 20 and the area to be welded, thereby improving welding efficiency. Optionally, L2 can be set to a value such as 0.5mm, 1.5mm, or 3mm. The specific setting should be selected based on the use environment of the second edge clamping sub-portion 32 and is not specifically limited here.

[0037] Specifically, the surface of the edge clamp 30 facing the tab is an arc-shaped surface, and the convex direction of the arc-shaped surface is the same as the convex direction of the welding tooth 20. This arrangement facilitates better contact between the edge clamp 30 and the non-welding area of ​​the tab, thereby further preventing the risk of vibration cracking of the tab structure.

[0038] Furthermore, the angle between the edge clamp 30 and the plane where the welding surface 11 is located is α, 1°≤α≤20°. When α>20°, the angle between the edge clamp 30 and the plane where the welding surface 11 is located is too large. At this time, it is necessary to apply excessive pressure between the welding teeth 20 and the tab before the edge clamp 30 can contact the non-welding area of ​​the tab. This may cause the welding teeth 20 to damage the structure of the area to be welded of the tab, which is not conducive to welding the tab to the connecting piece. When α<1°, the angle between the edge clamp 30 and the plane where the welding surface 11 is located is too small. This will result in a reduction in the contact area between the edge clamp 30 and the non-welding area of ​​the tab, thereby reducing the contact area between the edge clamp 30 and the non-welding area of ​​the tab, making it impossible to ensure that the edge clamp 30 effectively presses the non-welding area of ​​the tab, and unable to reduce the probability of the foil being compressed and deformed under ultrasonic vibration and cracking. Therefore, setting 1°≤α≤20° not only helps protect the tab structure and prevents damage, but also ensures the contact area between the edge clamp 30 and the non-welded area of ​​the tab, thereby ensuring that the edge clamp 30 effectively compresses the non-welded area of ​​the tab and reduces the probability of the foil being compressed and deformed under ultrasonic vibration and cracking. Optionally, α can be set to a value such as 1°, 10°, or 20°. The specific setting should be selected based on the operating environment of the edge clamp 30 and is not specifically limited here.

[0039] Specifically, the ultrasonic welding head includes a plurality of welding teeth 20, which are arranged in an array on the welding surface 11. This arrangement can ensure that the welding teeth 20 are evenly connected to the area to be welded on the tab during the welding process, thereby facilitating the welding of the tab and improving the welding strength between the tab and the connecting piece.

[0040] Furthermore, the welding teeth 20 include a hemispherical structure or a conical structure. In this way, the corresponding welding teeth 20 can be selected according to the use environment of the ultrasonic welding head, thereby improving the applicability and application range of the ultrasonic welding head.

[0041] In other embodiments of the present application, the welding teeth 20 can also be configured as a boss structure, etc., as long as the requirements of the ultrasonic welding head are met. In the above ultrasonic welding head, since the top surface of the welding teeth 20 is polygonal, the stress can be dispersed along the multiple sides of the polygon, so that the top surface of the polygon can disperse the stress of the ultrasonic welding head, so that the stress concentration of the ultrasonic welding head can be reduced without adding a protective sheet, preventing the tab from cracking during welding, ensuring welding quality, and effectively reducing costs.

[0042] At the same time, in certain embodiments, the welding tooth 20 may also include an edge, and the edge is arc-shaped. In this way, the risk of the edge puncturing the tab is avoided. Specifically, the arc-shaped edge can be a sharp edge that has been passivated. In one embodiment, the cross-section of the arc-shaped edge parallel to the top surface can be in the shape of a polynomial curve. The shape of the polynomial curve includes but is not limited to a circle, a parabola, an ellipse, a hyperbola, and the like. At the same time, the welding tooth 20 can also be a triangular prism, including three edges, all of which are arc-shaped. It is understood that in other embodiments, at least one edge of the polygonal prism is arc-shaped.

[0043] Specifically, a rounded corner structure 40 is provided on the side of the bead holding portion 30 away from the welding surface 11. The radius of the rounded corner structure 40 is R, and 0.5mm≤R≤3mm. When R>3mm, the radius of the rounded corner structure 40 is too large, which will cause the rounded corner structure 40 to occupy too much space, which is not conducive to the arrangement of the bead holding portion 30 and the welding surface 11. When R<0.5mm, the radius of the rounded corner structure 40 is too small, which cannot prevent the ultrasonic horn from shearing the tab during welding, thereby causing damage to the tab structure and failing to ensure the quality of the finished product. Therefore, setting 0.5mm≤R≤3mm is not only conducive to the arrangement of the bead holding portion 30 and the welding surface 11, but also can prevent the ultrasonic horn from shearing the tab during welding, avoiding damage to the tab structure, thereby ensuring the quality of the finished product. Optionally, R can be set to a value such as 0.5mm, 1.5mm or 3mm. The specific setting should be selected according to the use environment of the rounded corner structure 40 and is not specifically limited here.

[0044] At the same time, the surface of the welding tooth 20 may also be provided with a wear-resistant coating and an anti-stick coating, which can effectively extend the service life of the welding tooth 20 and improve the welding quality.

[0045] In a second aspect, an embodiment of the present invention provides an ultrasonic welding device, which includes the above-mentioned ultrasonic welding head.

[0046] By applying the technical solution of the present invention, a pressure edge portion 30 is provided around the circumference of the welding surface 11, and the height of the pressure edge portion 30 in the first direction is less than the height of the welding tooth 20 in the first direction. In this way, the welding head can suppress the deformation of the foil in the non-welding area during welding through the pressure edge portion 30 with a certain angle at the edge of the welding surface 11, thereby reducing the stress concentration of the tab structure, thereby reducing the probability of the foil in the non-welding area being compressed and deformed and cracked under ultrasonic vibration, thereby ensuring the yield rate after welding the tab and the soft connecting sheet.

[0047] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0048] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0049] In the description of the present invention, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0050] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0051] In addition, it should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this utility model.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An ultrasonic welding head for welding tabs and connecting pieces, characterized in that: The ultrasonic welding head comprises: The body has a first contact surface, wherein the first contact surface includes a welding surface and a connecting surface arranged circumferentially around the welding surface; Welding teeth, used for welding the to-be-welded area of ​​the tab, and protruding along a first direction on the welding surface; a pressure edge portion, arranged in a circumferential direction of the welding tooth, the pressure edge portion including the connecting surface, the connecting surface forming the pressure edge surface of the pressure edge portion, the pressure edge surface being used to abut against the non-welding area of ​​the tab, and the height of the pressure edge portion in the first direction being less than the height of the welding tooth in the first direction; Among them, the pressing surface is an arc surface, and the convex direction of the arc surface is the same as the convex direction of the welding tooth. The pressing surface and the welding surface have an angle, and the angle between the pressing portion and the plane where the welding surface is located is α, 1°≤α≤20°.

2. The ultrasonic horn according to claim 1, characterized in that: The area of ​​the welding surface is S1, the sum of the areas of the edge pressing surface and the welding surface is S2, and 0.36≤S1:S2≤0.

71.

3. The ultrasonic horn according to claim 1, characterized in that: The edge pressing portion includes a first edge pressing sub-portion extending along the second direction and a second edge pressing sub-portion extending along the third direction. The second direction and the third direction are perpendicular to each other and are both perpendicular to the first direction. The extension length of the first edge pressing sub-portion in the third direction is L1, and the extension length of the second edge pressing sub-portion in the second direction is L2, and L1=L2.

4. The ultrasonic horn according to claim 3, characterized in that: 0.5mm≤L1≤3mm, 0.5mm≤L2≤3mm.

5. The ultrasonic welding head according to any one of claims 1 to 4, characterized in that: A rounded corner structure is provided on a side of the edge pressing portion away from the welding surface, and the radius of the rounded corner structure is R, 0.5mm≤R≤3mm.

6. The ultrasonic welding head according to any one of claims 1 to 4, characterized in that: The welding teeth include a hemispherical structure or a conical structure.

7. The ultrasonic welding head according to any one of claims 1 to 4, characterized in that: The ultrasonic horn includes a plurality of welding teeth, and the plurality of welding teeth are arrayed on the welding surface.

8. An ultrasonic welding device, characterized in that: The ultrasonic welding device comprises the ultrasonic welding head according to any one of claims 1 to 7.

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