Ultrasonic welding device and ultrasonic welding method

Abstract

The invention discloses an ultrasonic welding device and an ultrasonic welding method.The ultrasonic welding device comprises a bottom die, the bottom die is provided with a positioning structure used for being in clearance fit with a welded object, and the positioning structure is arranged to be a positioning column or a positioning groove; when the positioning structure is a positioning column, the positioning column is in clearance fit with all the welded objects; and when the positioning structure is a positioning groove, at least one welded object is in clearance fit with the positioning groove. According to the scheme, the production cost can be saved, and the production efficiency can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic welding machines, and in particular to an ultrasonic welding device and an ultrasonic welding method. Background Art

[0002] Ultrasonic welding uses high-frequency vibration waves to transmit to the surfaces of two objects to be welded. Under pressure, the two surfaces rub against each other to form a fusion between the molecular layers. It is widely used in metal welding, especially in the automotive, electronics, medical equipment and other industries.

[0003] For welding of multiple objects, it is necessary to position the upper and lower objects or more objects respectively. Because during the welding process, when the objects are subjected to high-frequency and violent friction, they may move due to various factors such as the surface state of the material and impurities, which will affect the welding effect and even cause the material to be scrapped.

[0004] At present, the position of the object to be welded is mainly limited by designing special positioning tools. However, this method usually has the following problems. On the one hand, since all degrees of freedom of the object to be welded need to be limited, complex parts design is usually required. Especially for small and thin objects to be welded, the positioning structure needs to avoid contact with the welding head during welding, which is more difficult to design. On the other hand, the positioning tool needs to be disassembled before and after welding, which increases the production time and has low production efficiency. Summary of the invention

[0005] In order to solve the above problems, the present application provides an ultrasonic welding device and an ultrasonic welding method.

[0006] In a first aspect, an embodiment of the present application provides an ultrasonic welding device, including a bottom mold, wherein: The bottom mold is provided with a positioning structure for gap matching with the object to be welded, and the positioning structure is configured as a positioning column or a positioning groove; When the positioning structure is a positioning column, the positioning column is in clearance fit with all the objects to be welded; When the positioning structure is a positioning groove, at least one of the objects to be welded is loosely matched with the positioning groove.

[0007] In some embodiments, a welding head is further included. When the positioning structure is a positioning column, a receiving groove is provided on the working surface of the welding head corresponding to the positioning column.

[0008] In some embodiments, the height of the positioning column is not higher than the top of the uppermost object to be welded.

[0009] In some embodiments, when the object to be welded and the positioning post are gap-matched, the size of the gap between the positioning post and the object to be welded is 0.01 mm to 0.1 mm; When the object to be welded and the positioning groove are gap-matched, the size of the gap between the positioning groove and the object to be welded is 0.02 mm to 0.1 mm.

[0010] In some embodiments, an exhaust process hole is provided in the bottom mold or the positioning column.

[0011] In some embodiments, the top edge of the positioning post is configured to be chamfered.

[0012] In some embodiments, the support surface of the bottom mold is a toothed surface, and the contour edge of the support surface close to the positioning column is configured to be chamfered.

[0013] In a second aspect, an embodiment of the present application provides an ultrasonic welding method, which is used in the ultrasonic welding device described in the first aspect, and the method includes: Based on the material of the object to be welded that is in direct contact with the bottom mold, a corresponding bottom mold is selected as the current bottom mold, and a current welding head matched with the current bottom mold is selected; Installing the object to be welded onto the current bottom mold; Based on the total thickness of the object to be welded, setting welding parameters of the ultrasonic welding machine; The ultrasonic welding machine is used to perform welding work.

[0014] In some embodiments, the selecting a corresponding bottom mold as the current bottom mold based on the material of the object to be welded that is in direct contact with the bottom mold includes: When the material of the welded object in direct contact with the bottom die is aluminum, the first bottom die is selected as the current bottom die, and the welding teeth on the first bottom die have a tooth depth of 0.2-0.5 mm, a tooth spacing of 0.1-0.4 mm, and a tooth shape of staggered helical teeth; When the material of the object to be welded in direct contact with the bottom die is copper, the second bottom die is selected as the current bottom die, the tooth depth of the welding teeth on the second bottom die is 15%~30% of the thickness of the object to be welded in direct contact, the top width of the welding teeth is 0, the welding tooth angle is 60°~90°, and the tooth shape is staggered helical teeth.

[0015] The technical solution of this application has at least the following advantages: 1. By setting up a bottom mold with a self-positioning structure, during welding operations, the positioning of the object to be welded can be achieved through the clearance fit between the positioning structure and the object to be welded, without the need to design and use additional positioning tooling. On the one hand, this avoids complex part design and saves costs; on the other hand, it also saves time in disassembling and assembling positioning tooling and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the structure of the bottom mold in the ultrasonic welding device provided in Example 1 of the present application; Figure 2 It is a cross-sectional view of a bottom mold in an ultrasonic welding device provided in Example 1 of the present application; Figure 3 is a schematic diagram for reflecting the size parameters of welding teeth provided by an exemplary embodiment of the present application; Figure 4 It is a schematic diagram of the structure of a welding head in an ultrasonic welding device provided in Example 1 of the present application; Figure 5 is a cross-sectional view of an ultrasonic welding device in Example 2 of the present application; Figure 6 is a cross-sectional view of an ultrasonic welding device in Example 3 of the present application; Figure 7 is a flow chart of an ultrasonic welding method provided by an exemplary embodiment of the present application.

[0018] Description of reference numerals: 1. Bottom mold; 11. Mounting groove; 12. Support surface; 13. Annular groove; 2. Positioning column; 3. Positioning groove; 4. Welding head; 41. Working surface; 42. Accommodating groove; 5. First workpiece; 6. Second workpiece; 7. Third workpiece; 8. Fourth workpiece; 81. Main body; 82. Raised portion. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0021] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0023] The present application provides an ultrasonic welding device, such as Figures 1 to 7 As shown, the ultrasonic welding device includes an ultrasonic welding machine and a bottom mold 1 for the ultrasonic welding machine. A positioning structure is provided on the bottom mold 1, and the positioning structure realizes the positioning of all objects to be welded by gap matching with the objects to be welded. The positioning structure can be a positioning column 2 or a positioning groove 3. When the positioning structure is a positioning column 2, the positioning column 2 is gap matched with all objects to be welded; when the positioning structure is a positioning groove 3, at least one object to be welded is gap matched with the positioning groove 3. At the same time, the size range of the gap between the positioning column 2 and the object to be welded is 0.01mm~0.1mm, and the size range of the gap between the positioning groove 3 and the object to be welded is 0.02-0.1mm.

[0024] The following will be combined with the attached Figures 1 to 7 , the two situations are respectively explained through multiple embodiments. Example

[0025] Reference Figure 1 and Figure 2 In this embodiment, the positioning structure includes a positioning column 2, and a mounting groove 11 having a size matching that of the positioning column 2 is opened in the bottom mold 1. By clamping the bottom of the positioning column 2 in the mounting groove 11, a stable connection between the bottom mold 1 and the positioning column 2 can be achieved.

[0026] The bottom mold 1 with the positioning column 2 is used to limit the welded object with holes, and the size and shape of the positioning column 2 match the holes on the welded object. On the one hand, due to the existence of the gap, the welded object can be smoothly placed on the positioning column 2. On the other hand, since the gap size is not less than 0.01mm, it can be ensured to be greater than the amplitude of the welded object during welding to avoid affecting the welding. At the same time, since the gap size is not greater than 0.1mm, it will not cause excessive positional displacement of the material after welding.

[0027] Reference Figure 1 and Figure 2 The top edge of the positioning column 2 is configured to be chamfered to facilitate the placement of the welded object. In addition, in order to reduce the possibility of a closed space being generated at the bottom of the mounting groove 11 when the positioning column 2 is pressed into the mounting groove 11, resulting in the inability to exhaust air, an exhaust process hole can be opened on the top or side of the positioning column 2, or an exhaust process hole connected to the mounting groove 11 can be opened on the bottom mold 1.

[0028] Reference Figure 2 The support surface 12 of the bottom mold 1 is configured as a toothed surface for supporting the object to be welded that is in direct contact with the bottom mold 1. The contour edge of the support surface 12 close to the positioning column 2 is configured to be chamfered, that is, the top edge of the mounting groove 11 is chamfered to prevent the object to be welded from being stuck in the gap between the toothed surface and the positioning column 2, causing difficulty in removing the material.

[0029] After the objects to be welded are placed, the positioning column 2 is gap-matched with all the objects to be welded at the same time, and the height of the positioning column 2 is not higher than the top of the object to be welded located at the top.

[0030] Among them, in order to ensure the welding effect of objects of different materials, a plurality of bottom molds 1 can be provided, and different bottom molds 1 are used for objects of different materials. For example, a first bottom mold for objects of aluminum and a second bottom mold for objects of copper can be configured. For the first bottom mold, the tooth depth of the welding teeth thereon is 0.2~0.5mm, the tooth spacing is 0.1~0.4mm, and the tooth shape is staggered helical teeth to avoid aluminum deformation, adhesion, and overflow. For the second bottom mold, the tooth depth of the welding teeth thereon is 15%~30% of the thickness of the object of direct contact, the top tooth width of the welding teeth is 0, the welding tooth angle is 60°~90°, and the tooth shape is staggered helical teeth to increase the energy introduction depth and improve the welding efficiency. Among them, the tooth depth D, tooth spacing S, welding tooth angle α, top tooth width W1, such as Figure 3 shown.

[0031] Reference Figure 2 and Figure 4The working surface 41 of the horn 4 in the ultrasonic welding machine is also a toothed surface, and a receiving groove 42 facing the positioning column 2 is provided on the working surface 41, and the receiving groove 42 can completely accommodate the top of the positioning column 2. During the ultrasonic welding process, as the welding teeth on the horn 4 and the bottom mold 1 penetrate into the material, the positioning column 2 in the middle of the bottom mold 1 will gradually protrude from the material. Due to the presence of the receiving groove 42, the positioning column 2 can be prevented from colliding with the horn 4, causing abnormal vibration and mold damage.

[0032] The welding teeth on the working surface 41 of the welding head 4 can be sharp teeth, which can firmly grasp the object to be welded above to avoid abnormal collision between the object to be welded and the positioning column 2, resulting in energy loss or wear or even breakage of the positioning column 2. At the same time, the tooth depth of the welding teeth on the working surface 41 of the welding head 4 is set to 8-12% of the thickness of the object to be welded above, so that the deformation of the material on the welding surface is small and the overflow is small.

[0033] Furthermore, for the object to be welded, it is usually necessary to leave some unwelded areas on the welding surface at the same time, so as to cooperate with the connector in the subsequent process. Therefore, a avoidance groove can be set on the support surface 12 of the bottom mold 1, and a avoidance groove can also be set on the working surface 41 of the welding head 4, so as to leave unwelded areas on the welding surface of the object to be welded that is in direct contact. Among them, the avoidance groove can be opened only on the support surface 12 of the bottom mold 1 or on the working surface 41 of the welding head 4, or it can be opened on both the working surface 41 of the welding head 4 and the support surface 12 of the bottom mold 1. Example

[0034] This embodiment specifically shows the cooperation between a bottom mold 1 with positioning columns 2 and a workpiece.

[0035] Reference Figure 5 In this embodiment, the positioning column 2 and the bottom mold 1 are integrally formed.

[0036] like Figure 5 As shown, the welded objects include a first workpiece 5 and a second workpiece 6, and the first workpiece 5 is an aluminum bar with a thickness of 5 mm, and the second workpiece 6 is a copper ring with a thickness of 2 mm and a diameter of 18 mm, and a hole with a diameter of 8 mm is opened on the first workpiece 5 and the second workpiece 6. The diameter of the positioning column 2 is 7.9 mm, and the first workpiece 5 and the second workpiece 6 are sequentially sleeved on the positioning column 2, and both are clearance-matched with the positioning column 2, and the top of the positioning column 2 is lower than the top of the second workpiece 6 located above.

[0037] Reference Figure 5A circle of annular grooves 13 are provided on the supporting surface 12 of the bottom mold 1 located around the bottom of the positioning column 2. On the one hand, the annular groove 13 can increase the root strength of the positioning column 2 and prevent the first workpiece 5 from squeezing into the angle between the positioning column 2 and the welding tooth, resulting in difficulty in removing after welding. On the other hand, it can also serve as an avoidance groove to leave a circle of unwelded area at the bottom of the first workpiece 5.

[0038] Reference Figure 5 In this embodiment, the diameter of the welding head 4 is 17.5 mm, which is close to the diameter of the second workpiece 6. A receiving groove 42 with a diameter of 10 mm is provided on the working surface 41 of the welding head 4, which is larger than the diameter of the positioning column 2. At the same time, since the receiving groove 42 is also larger than the hole on the second workpiece 6, the receiving groove 42 can also be used as an avoidance groove on the welding head 4, thereby leaving a circle of unwelded area on the top of the second workpiece 6.

[0039] In this embodiment, the welding teeth on the welding head 4 can be arranged crosswise at 90°, and the tooth depth is 0.2mm, the top tooth width is 0.15mm, the bottom tooth width is 0.38mm, the welding tooth angle is 60°, and the tooth spacing is 0mm. The welding teeth on the bottom mold 1 are arranged crosswise at 90°, and the tooth depth is 0.5mm, the top tooth width is 0, the bottom tooth width is 2mm, the welding tooth angle is 120°, the tooth root is provided with a chamfer with a radius of 0.5mm, and the tooth spacing is 0.2mm. Among them, the tooth depth D, the tooth spacing S, the welding tooth angle α, the top tooth width W1, and the bottom tooth width W2 are as follows Figure 3 shown. Example

[0040] Reference Figure 6 In this embodiment, the positioning structure includes a positioning groove 3 provided on the support surface 12 of the bottom mold 1, and the diameter of the positioning groove 3 is 10.5 mm and the depth is 3 mm. The objects to be welded include a third workpiece 7 and a fourth workpiece 8, wherein the third workpiece 7 is an aluminum bar with a thickness of 4 mm and a through hole with a diameter of 10 mm provided thereon, and the through hole is directly opposite to the positioning groove 3, and the fourth workpiece 8 is a copper ring, which includes a main body 81 with an outer diameter of 14 mm and a raised portion 82 with a diameter of 9.9 mm, and the height of the main body 81 is 4 mm and is placed on the third workpiece 7, and the raised portion 82 passes through the through hole on the third workpiece 7 and enters the positioning groove 3 below by 1 mm, thereby simultaneously matching the clearance between the third workpiece 7 and the positioning groove 3.

[0041] Reference Figure 6 In this embodiment, the diameter of the welding head 4 is 15 mm, which is close to the outer diameter of the main body 81 of the fourth workpiece 8. A 10 mm diameter and 1 mm deep avoidance groove can be provided on the working surface 41 of the welding head 4 to leave an unwelded area on the top of the fourth workpiece 8.

[0042] The ultrasonic welding device provided in the above embodiment of the present application, by providing a bottom mold 1 with a self-contained positioning structure, can achieve positioning of the object to be welded by the clearance fit between the positioning structure and the object to be welded during welding operation, without the need to design and use additional positioning tooling. On the one hand, it avoids complex part design and saves costs, and on the other hand, it also saves time for disassembling and assembling positioning tooling, thereby improving production efficiency. In addition, for objects to be welded of different shapes, the positioning structure can be set as a positioning column 2 or a positioning groove 3, which has a wide range of applicability.

[0043] Based on the ultrasonic welding device described above, the present application also provides an ultrasonic welding method, referring to Figure 7 , the method comprises the following steps: S1: Based on the material of the object to be welded that is in direct contact with the bottom mold, the corresponding bottom mold is selected as the current bottom mold, and the current welding head that matches the current bottom mold is selected.

[0044] For example, for the same ultrasonic welding machine, multiple replaceable bottom molds and welding heads can be configured, or multiple ultrasonic welding machines with different bottom molds and different welding heads can be set. When welding is required, the corresponding bottom mold is selected as the current bottom mold according to the material of the object to be welded that needs to be in direct contact with the bottom mold, and the current welding head matching the current bottom mold is selected.

[0045] Further, in this embodiment, the ultrasonic welding machine may be configured with a first bottom mold and a second bottom mold, and the tooth depth of the welding teeth in the support surface of the first bottom mold is 0.2~0.5mm, the tooth spacing is 0.1~0.4mm, and the tooth shape is staggered helical teeth, and the tooth depth of the welding teeth in the support surface of the second bottom mold is 15%~30% of the thickness of the directly contacted welded object, the top width of the welding teeth is 0, the welding tooth angle is 60°~90°, and the tooth shape is staggered helical teeth. At this time, this step may include the following content: When the material of the object to be welded that is in direct contact with the bottom mold is aluminum, the first bottom mold is selected as the current bottom mold.

[0046] When the material of the object to be welded that is in direct contact with the bottom mold is copper, the second bottom mold is selected as the current bottom mold.

[0047] S2: Install the object to be welded onto the current base mold.

[0048] Exemplarily, the object to be welded is placed on the current bottom mold, and the positioning of the object to be welded is achieved through the clearance fit between the positioning structure and the object to be welded.

[0049] S3: Based on the total thickness of the object to be welded, set the welding parameters of the ultrasonic welding machine.

[0050] Exemplarily, the welding parameters of the ultrasonic welding machine are set according to the total thickness of the object to be welded, wherein the total thickness of the object to be welded refers to the difference between the highest point and the lowest point of the part to be welded after all the objects to be welded are installed.

[0051] Furthermore, when the total thickness of the welded object is less than 5mm, the welding parameters are set to a welding power of 2~4kW, an amplitude of <25um, and after welding, the position of the welded object is less than 0.1mm. When the total thickness of the welded object is greater than or equal to 5mm, the welding parameters are set to a welding power of 5~8kW, an amplitude of <50um, and after welding, the position of the welded object is less than 0.2mm.

[0052] S4: Use ultrasonic welding machine to perform welding work.

[0053] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. An ultrasonic welding device, characterized in that: It comprises a bottom mold (1), wherein: The bottom mold (1) is provided with a positioning structure for gap matching with the object to be welded, and the positioning structure is configured as a positioning column (2) or a positioning groove (3); When the positioning structure is a positioning column (2), the positioning column (2) is clearance-matched with all the objects to be welded; When the positioning structure is a positioning groove (3), at least one of the objects to be welded is clearance-matched with the positioning groove (3).

2. The ultrasonic welding device according to claim 1, characterized in that: It also comprises a welding head. When the positioning structure is a positioning column (2), a receiving groove (42) is provided on a working surface (41) of the welding head (4) corresponding to the positioning column (2).

3. The ultrasonic welding device according to claim 1, characterized in that: The height of the positioning column (2) is not higher than the top of the object to be welded located at the top.

4. The ultrasonic welding device according to claim 1, characterized in that: When the object to be welded and the positioning column (2) are gap-matched, the size of the gap between the positioning column (2) and the object to be welded is 0.01 mm to 0.1 mm; When the object to be welded and the positioning groove (3) are clearance-matched, the size of the clearance between the positioning groove (3) and the object to be welded is 0.02 mm to 0.1 mm.

5. The ultrasonic welding device according to claim 1, characterized in that: An exhaust process hole is provided in the bottom mold (1) or the positioning column (2).

6. The ultrasonic welding device according to claim 1, characterized in that: The top edge of the positioning column (2) is configured to be chamfered.

7. The ultrasonic welding device according to claim 1, characterized in that: The supporting surface (12) of the bottom mold (1) is a toothed surface, and the contour edge of the supporting surface (12) close to the positioning column (2) is configured to be chamfered.

8. The ultrasonic welding device according to claim 2, characterized in that: The supporting surface (12) of the bottom mold (1) and / or the working surface (41) of the welding head (4) are provided with an avoidance groove, and the avoidance groove is used to leave an unwelded area on the welded surface of the welded object.

9. An ultrasonic welding method, characterized in that: The method is used for the ultrasonic welding device according to any one of claims 1 to 8, and the method comprises: Based on the material of the object to be welded that is in direct contact with the bottom mold, the corresponding bottom mold is selected as the current bottom mold, and a current welding head matched with the current bottom mold is selected; Installing the object to be welded onto the current bottom mold; Setting welding parameters of the ultrasonic welding machine based on the total thickness of the object to be welded; The ultrasonic welding machine is used to perform welding work.

10. The ultrasonic welding method according to claim 9, characterized in that: The selecting a corresponding bottom mold as the current bottom mold based on the material of the object to be welded that is in direct contact with the bottom mold includes: When the material of the welded object in direct contact with the bottom die is aluminum, the first bottom die is selected as the current bottom die, and the welding teeth on the first bottom die have a tooth depth of 0.2-0.5 mm, a tooth spacing of 0.1-0.4 mm, and a tooth shape of staggered helical teeth; When the material of the object to be welded in direct contact with the bottom die is copper, the second bottom die is selected as the current bottom die, the tooth depth of the welding teeth on the second bottom die is 15%~30% of the thickness of the object to be welded in direct contact, the top width of the welding teeth is 0, the welding tooth angle is 60°~90°, and the tooth shape is staggered helical teeth.

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