Ultrasonic rivet welding head, ultrasonic rivet welding equipment and rivet welding method

Abstract

The invention belongs to the technical field of ultrasonic rivet welding, and discloses an ultrasonic rivet welding head, ultrasonic rivet welding equipment and a rivet welding method. Wherein the ultrasonic rivet welding head comprises a connecting section, a stabbing section and a shaping section, the stabbing section is arranged at the far end of the connecting section, and the stabbing section has the outer diameter which is gradually increased from the stabbing section to the connecting section, so that when the ultrasonic rivet welding head is axially propelled and applies high-frequency mechanical vibration, the stabbing section can stabbing a metal riveting piece; guiding the metal riveting piece to generate initial plastic deformation; the shaping section is adjacent to the piercing section, and the shaping section is configured to further guide the material of the metal riveting piece to expand after the piercing section pierces the metal riveting piece so as to form the locking structure. According to the ultrasonic rivet welding head, a metal riveting piece can be plastically deformed under small downward pressure to form a locking structure, so that ultrasonic rivet welding equipment with the ultrasonic rivet welding head can directly perform rivet welding on a metal workpiece, the rivet welding cost of the metal workpiece is reduced, and the rivet welding efficiency and quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic riveting welding, and in particular to an ultrasonic riveting welding head, ultrasonic riveting welding equipment and a riveting welding method. Background Art

[0002] Riveting welding, a key process for joining metal materials, is widely used in automotive manufacturing, electronic component packaging, aerospace, and other fields. Riveting welding applies vertical mechanical pressure to metal riveted parts, causing them to plastically deform, forming an interlocking structure between the two workpieces and achieving a physical connection. However, with the increasing demand for manufacturing precision and production efficiency in modern industry, traditional riveting welding processes have gradually exposed significant technical limitations.

[0003] First, the traditional process requires applying extremely high pressure (usually exceeding 5000N) to cause plastic deformation of the metal material in order to achieve an effective connection. To do this, a high-power hydraulic system or heavy-duty stamping equipment must be equipped, which leads to large-scale equipment and increased energy consumption. Ultra-high pressure can also easily cause excessive deformation of the material, affecting the structural integrity of the component. Secondly, the contact interface formed by traditional riveting has significant electrical performance defects, that is, the metal surface oxide layer, processing residues and microscopic concave-convex structures are difficult to completely break under conventional pressure, resulting in a contact resistance fluctuation range far higher than the industry standard, requiring electroplating or secondary welding processing. In addition, the equipment vibration noise (usually exceeding 85dB) and long-period pressure maintenance requirements (about 5 to 8 seconds / point) caused by the high-pressure process further limit the optimization of production rhythm, resulting in low production efficiency.

[0004] Compared with traditional riveting welding process, existing ultrasonic welding has the advantages of low cost, high efficiency and reliable connection. However, the heat generated by ultrasonic friction makes it difficult for the metal to reach the plastic deformation temperature, and the pressure exerted by the ultrasonic riveting welding head on the metal cannot cause the metal to produce plastic deformation. As a result, the existing ultrasonic riveting welding technology cannot be directly applied to metal workpieces. That is, the current riveting connection between two metal parts still requires mechanical riveting to achieve the riveting of the two metal parts, and then laser welding. Ultimately, not only the production cost remains high, but the efficiency and quality of riveting are also in urgent need of improvement. Summary of the Invention

[0005] The object of the present invention is to provide an ultrasonic riveting welding head, an ultrasonic riveting welding device and a riveting welding method to reduce the cost of riveting welding of metal workpieces and improve the efficiency and quality of riveting welding of metal workpieces.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] An ultrasonic riveting welding head is used to connect to an acoustic component and ultrasonically rivet a metal riveted part, the ultrasonic riveting welding head comprising:

[0008] a connecting section for connecting to an acoustic component to transmit high-frequency mechanical vibrations;

[0009] a piercing section, disposed at the distal end of the connecting section, the piercing section having an outer diameter or outer profile that gradually increases from the piercing section toward the connecting section, so that when the ultrasonic riveting welding head is axially advanced and applies high-frequency mechanical vibration, the piercing section can penetrate the metal riveted part and guide the metal riveted part to undergo initial plastic deformation; and

[0010] A shaping section is adjacent to the piercing section, and the shaping section is configured to further guide the material of the metal rivet to expand after the piercing section pierces the metal rivet to form a locking structure.

[0011] Preferably, the piercing section is formed into a cone or wedge shape, so that the piercing section forms point contact or line contact with the surface to be processed of the metal rivet.

[0012] Preferably, one end of the shaping section adjacent to the piercing section is formed as a flattening area, and the flattening area has a pressing surface substantially perpendicular to the axis of the ultrasonic riveting head, and the flattening area is used to compact the top of the metal riveted part after deformation.

[0013] Preferably, the junction between the piercing section and the shaping section is in an arc-shaped transition.

[0014] An ultrasonic riveting welding head is used to connect to an acoustic component and ultrasonically rivet a metal riveted part having a preset connection hole, the ultrasonic riveting welding head comprising:

[0015] a connecting section for connecting to an acoustic component to transmit high-frequency mechanical vibrations;

[0016] an insertion section, disposed at the distal end of the connecting section, the insertion section having an outer diameter or outer profile that gradually increases from the insertion section toward the connecting section, so as to abut against the inner wall of the connecting hole when the ultrasonic riveting welding head is axially advanced and applies high-frequency mechanical vibration, thereby applying an initial force to the inner wall of the connecting hole; and

[0017] A shaping section is adjacent to the insertion section, and the shaping section is configured to further guide the material of the metal rivet to expand after the insertion section is inserted into the connecting hole, so as to form a locking structure.

[0018] Preferably, the ultrasonic riveting welding head further comprises:

[0019] The piercing section is adjacent to one end of the inserting section away from the shaping section. The piercing section can penetrate the bottom of the connecting hole and guide the metal rivet to undergo initial plastic deformation.

[0020] Preferably, one end of the insertion section adjacent to the piercing section is formed as a transition zone, and the transition zone is used to limit the depth of the piercing section penetrating into the connecting hole.

[0021] Preferably, the outer surface of the insertion section is formed into a frustum, a spherical table, an arcuate convex surface or a multi-section combination surface.

[0022] Preferably, one end of the shaping section adjacent to the insertion section is formed as a flattening area, the flattening area has a pressing surface substantially perpendicular to the axis of the ultrasonic riveting head, and the flattening area is used to compact the top of the metal riveted part after deformation.

[0023] The ultrasonic riveting equipment comprises a bottom die for carrying a metal riveted part and an ultrasonic riveting head. The ultrasonic riveting head is driven by a transfer mechanism and is used to act on the metal riveted part placed on the bottom die.

[0024] The riveting method is performed using ultrasonic riveting equipment with an ultrasonic riveting welding head, and includes the following steps:

[0025] The first metal member and the second metal member are sequentially stacked on a bottom mold of an ultrasonic riveting device; wherein the first metal member is located above the second metal member, a through hole is formed on the first metal member, and a connecting post penetrating the through hole is connected to the second metal member;

[0026] The ultrasonic riveting welding head is driven to move toward the connecting post until the piercing section penetrates into the interior of the connecting post; when the piercing section penetrates into the connecting post to a preset depth, the ultrasonic riveting welding device triggers ultrasonic welding;

[0027] The ultrasonic riveting welding head transmits high-frequency mechanical vibration to the connecting column and maintains it for a preset time until the connecting column extends out of the material of the first metal part and expands to form a locking structure.

[0028] The riveting method is performed using ultrasonic riveting equipment with an ultrasonic riveting welding head, and includes the following steps:

[0029] The first metal member and the second metal member are sequentially stacked on the bottom mold of the ultrasonic riveting equipment; wherein the first metal member is located above the second metal member, the first metal member is provided with a through hole, and the second metal member is connected to a connecting post penetrating the through hole, and the top of the connecting post is provided with a connecting hole;

[0030] Driving the ultrasonic riveting welding head to move toward the connecting column until the insertion section is inserted into the interior of the connecting hole; when the insertion section abuts against the inner wall of the connecting hole, the ultrasonic riveting welding device triggers ultrasonic welding;

[0031] The ultrasonic riveting welding head transmits high-frequency mechanical vibration to the connecting column and maintains it for a preset time until the material of the connecting column at the preset connection hole position expands to form a locking structure.

[0032] Beneficial effects of the present invention:

[0033] The ultrasonic riveting welding head of the present invention utilizes a connecting section to achieve the fixation of the ultrasonic riveting welding head, and the piercing section is arranged at one end of the shaping section close to the metal riveted part. When the metal riveted part is riveted, the piercing section penetrates into the interior of the metal riveted part to destroy the continuous structure of the metal riveted part, and the metal riveted part is guided to undergo initial plastic deformation through the gradually increasing outer diameter or outer contour of the piercing section, so that the metal riveted part forms a thin-walled structure with lower strength in the area around the piercing section corresponding to the metal riveted part. The shaping section further applies pressure to the metal riveted part and transmits high-frequency mechanical vibration, and guides the material expansion of the metal riveted part to finally form a locking structure. Compared with the method of directly roughening the end of the metal riveted part, it is more labor-saving, so that the mechanical interlocking of the two metal workpieces can be achieved under a smaller downward pressure, so that the ultrasonic riveting welding equipment with an ultrasonic riveting welding head can directly perform riveting welding on the metal workpiece, so as to reduce the cost of riveting welding of metal workpieces and improve the efficiency and quality of riveting welding.

[0034] The ultrasonic riveting welding head of the present invention pre-sets a connection hole on the metal riveted part to destroy the continuous structure of the metal riveted part, so that the position where the connection hole is set on the metal riveted part forms a thin-walled structure with lower strength; when the metal riveted part is riveted, the insertion section is directly inserted into the preset connection hole of the metal riveted part, and the outer wall of the insertion section directly abuts the edge of the opening of the connection hole and transmits high-frequency mechanical vibration, so that the thin-walled structure is quickly deformed by a large pressure, and then the metal riveted part is further squeezed by the shaping section and the material expansion of the metal riveted part is guided to finally form a locking structure; the mechanical interlocking of two metal workpieces can be quickly achieved under a small downward pressure, so that the ultrasonic riveting welding equipment with the ultrasonic riveting welding head can directly perform riveting welding on the metal workpiece, thereby reducing the cost of riveting the metal workpieces while improving the efficiency and quality of riveting.

[0035] The ultrasonic riveting welding equipment of the present invention applies pressure to the metal riveted parts on the metal workpiece by an ultrasonic riveting welding head arranged above the bottom mold, and can complete the riveting and welding of the metal riveted parts at one time. The ultrasonic riveting welding equipment can achieve riveting welding of the metal workpiece by only replacing the ultrasonic riveting welding head, thereby improving the applicability of the equipment.

[0036] The riveting welding method of the present invention directly performs riveting welding of two metal workpieces by using ultrasonic riveting welding equipment with an ultrasonic riveting welding head. Compared with the traditional process of first riveting and then welding, the method is lower in cost and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the ultrasonic riveting welding head before riveting the connecting column in the first embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the ultrasonic riveting welding head after riveting the connecting column in the first embodiment of the present invention;

[0039] Figure 3 This is a schematic structural diagram of an ultrasonic riveting welding head in a second embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the ultrasonic riveting welding head before riveting the connecting column in the second embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the ultrasonic riveting welding head after riveting the connecting column in the second embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the ultrasonic riveting welding head after riveting the connecting column in the third embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the ultrasonic riveting welding head after riveting the connecting column in the third embodiment of the present invention.

[0044] In the picture:

[0045] 100, first metal part; 101, through hole; 200, second metal part; 201, connecting column; 2011, connecting hole; 2012, limiting portion; 300, sealing ring;

[0046] 1. Insertion section; 2. Shaping section; 21. Flattening area; 3. Insertion section; 31. Transition area; 4. Bottom mold. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0048] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0049] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0050] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0051] Refer to the following Figures 1 to 7 The ultrasonic riveting welding head, ultrasonic riveting welding equipment and riveting welding method provided by the present invention are described.

[0052] This ultrasonic riveting equipment includes a frame, a workbench, a base mold 4, an acoustic assembly, and an ultrasonic riveting head. The acoustic assembly includes an ultrasonic generator and an ultrasonic transducer. Both the workbench and the ultrasonic generator are connected to the frame. The base mold 4 is attached to the workbench, and the ultrasonic transducer is slidably connected to the frame in a predetermined direction. The ultrasonic transducer is driven by a transfer mechanism and is electrically connected to the ultrasonic generator. The ultrasonic riveting head is connected to the ultrasonic transducer and is used to interact with the metal riveted part placed on the base mold 4. The transfer mechanism can drive the ultrasonic riveting head to move in a predetermined direction relative to the base mold 4 to perform riveting on the metal riveted part.

[0053] The ultrasonic riveting welding head is designed to plastically deform the metal riveted parts through a small downward force, so that the ultrasonic riveting welding equipment can rivet two metal components to reduce the cost of riveting between metal workpieces while improving the efficiency and quality of riveting. Figure 1As an example, in this embodiment, the two metal components are a first metal member 100 and a second metal member 200. The first metal member 100 has a through-hole 101, and the second metal member 200 is connected to a connecting post 201. When the first metal member 100 is stacked on top of the second metal member 200, the connecting post 201 engages with the through-hole 101 and extends out of the first metal member 100. In this embodiment, the connecting post 201 serves as a metal rivet. Furthermore, a sealing ring 300 is provided between the first metal member 100 and the second metal member 200 to enhance the sealing between the first metal member 100 and the second metal member 200.

[0054] The specific structure of the ultrasonic riveting welding head and the riveting welding method are shown in the following specific embodiments.

[0055] Example 1

[0056] Reference Figure 1 and Figure 2 In a first aspect, this embodiment provides an ultrasonic riveting welding head. The ultrasonic riveting welding head includes a connecting section, a piercing section 1, and a shaping section 2. The connecting section, the shaping section 2, and the piercing section 1 are arranged in sequence, and the connecting section is connected to the ultrasonic transducer of the ultrasonic riveting welding equipment. The piercing section 1 has an outer diameter or outer profile that gradually increases from itself toward the connecting section, so that when the ultrasonic riveting welding head is axially advanced and high-frequency mechanical vibration is applied, the piercing section 1 can penetrate the metal riveted part, i.e., the connecting column 201, and guide the metal riveted part to undergo initial plastic deformation. The shaping section 2 is configured to further guide the material expansion of the metal riveted part to form a locking structure after the piercing section 1 penetrates the metal riveted part.

[0057] As described above, when the connecting post 201 is riveted, the piercing section 1 penetrates into the interior of the connecting post 201 to destroy the continuous structure of the connecting post 201, and the piercing section 1 guides the connecting post 201 to undergo initial plastic deformation by gradually increasing the outer diameter or outer contour, so that the area around the connecting post 201 corresponding to the piercing section 1 forms a thin-walled structure with lower strength, and then the shaping section 2 further applies pressure to the connecting post 201 and transmits high-frequency mechanical vibration, and guides the material of the connecting post 201 to expand, so that the top of the connecting post 201 forms a limit portion 2012 that abuts against the upper surface of the first metal member 100 (refer to Figure 2 ), ultimately forming a locking structure. Furthermore, the high-frequency tangential vibration of the ultrasonic riveting horn causes microscopic slippage on the contact surface, and frictional heat softens connecting post 201, making it easier to expand and deform. When the temperature of connecting post 201 reaches the material recrystallization point, atomic diffusion at the interface forms a micro-metallurgical bond, achieving riveting and welding. Ultimately, after expansion and deformation, connecting post 201 forms a tight metal-to-metal bond with the top surface of first metal component 100 and the sidewalls of through-hole 101, simultaneously meeting sealing, mechanical connection strength, and electrical connection performance.

[0058] It is understood that by replacing the ultrasonic riveting welding head of existing ultrasonic riveting equipment, metal components can be riveted and welded, thereby reducing the cost of riveting between metal workpieces. This is more efficient than the existing method of mechanical riveting followed by laser welding. In addition, compared with traditional face-to-face welding methods, the limiter 2012 created by the expansion and deformation of the connecting column 201 greatly enhances the mechanical connection strength. The second metal component 200 must be destroyed before the riveted weld can be broken, thereby improving the quality of the weld.

[0059] It should be noted that the following content uses the orientation of the ultrasonic riveting welding head set in the vertical direction as an example. In this embodiment, the connecting section, the piercing section 1 and the shaping section 2 are set as an integral part, that is, the ultrasonic riveting welding head is processed from a single blank to ensure the strength of the ultrasonic riveting welding head itself. In some other embodiments, the connecting section, the piercing section 1 and the shaping section 2 can also be manufactured separately, and then the three are fixedly connected.

[0060] Furthermore, the piercing section 1 is formed into a cone or wedge shape to form point contact or line contact with the surface to be processed of the connecting post 201. In this embodiment, the piercing section 1 is a cone, that is, in this embodiment, when the piercing section 1 and the connecting post 201 initially abut, the two are in point contact. This greatly increases the pressure exerted by the piercing section 1 on the top of the connecting post 201, making it easier for the piercing section 1 to penetrate the interior of the connecting post 201, causing the connecting post 201 to undergo rapid plastic deformation. The cone also guides the deformation of the connecting post 201.

[0061] Optionally, the included angle of the tip of the piercing section 1 is α, α = 30 to 90 degrees, to balance the strength and sharpness of the piercing section 1. In this embodiment, α is 45 degrees. Of course, in other embodiments, α can also be 30 degrees, 40 degrees, 50 degrees, 60 degrees, or 90 degrees. The specific angle depends on many factors such as the material of the piercing section 1 and the material of the connecting column 201, and can be adjusted according to actual needs.

[0062] Optionally, the height of the piercing section 1 is H1, and the height of the connecting post 201 protruding from the first metal member 100 is H2, where H1 = 1.4*H2 to 2*H2. This limits the depth of the piercing section 1 penetrating the connecting post 201, i.e., limits the degree of deformation of the connecting post 201. In this embodiment, H1 = 1.5*H2 is used as an example, i.e., the height of the piercing section 1 is 1.5 times the height of the connecting post 201 protruding from the first metal member 100. Of course, in other embodiments, the height may be 1.4 times, 1.6 times, or 2 times. The specific height can be adjusted based on actual needs.

[0063] Furthermore, the end of the shaping section 2 adjacent to the piercing section 1 is formed into a flattening area 21. The flattening area 21 has a pressing surface substantially perpendicular to the axis of the ultrasonic riveting welding head. The flattening area 21 is used to compact the top of the connecting column 201 after deformation. Specifically, in this embodiment, the shaping section 2 is cylindrical, and the piercing section 1 and the shaping section 2 are coaxial. The cross-sectional area of the end of the shaping section 2 at the end adjacent to the piercing section 1 is greater than the cross-sectional area of the end of the piercing section 1, so that the flattening area 21 is formed at the end of the shaping section 2, and the flattening area 21 is arranged in an annular shape.

[0064] Based on the above, after the insertion section 1 penetrates the connecting post 201, the annular flattening area 21 abuts the annular area at the top of the connecting post 201, thereby achieving final pressure and energy transfer. This pressurizes the deformed portion of the connecting post 201 tightly against the top surface of the first metal component 100, compacting the top of the connecting post 201 and enhancing the strength of the mechanical connection. At the same time, the flattening area 21 increases the contact area between the ultrasonic riveting head and the connecting post 201 and improves the surface smoothness of the connecting post 201.

[0065] Furthermore, in this embodiment, the adjacent part of the piercing section 1 and the shaping section 2 is an arc-shaped transition, and the center of the arc is located outside the ultrasonic riveting welding head. It can be understood that the edge of the piercing section 1 adjacent to the flattening area 21 has a circular chamfer to form an arc-shaped transition surface between the outer periphery of the piercing section 1 and the flattening area 21, which can not only reduce stress concentration and improve the structural strength of the ultrasonic riveting welding head, but also increase the contact area between the ultrasonic riveting welding head and the connecting column 201; in addition, the top of the connecting column 201 is plasticized by the arc surface, so that the top of the connecting column 201 is an arc surface to reduce stress concentration.

[0066] For example, in this embodiment, the connecting column 201 is also arranged in a cylindrical shape. Of course, in other embodiments, the connecting column 201 can also be arranged in a polygonal column or a polygonal pyramid. In this embodiment, the diameter of the shaping section 2 is D1, and the diameter of the connecting column 201 is D2. D1 = 1.2 * D2 ~ 1.8 * D2, so that the diameter of the shaping section 2 is larger than the diameter of the top of the connecting column 201 after deformation, thereby ensuring the contact area between the ultrasonic riveting welding head and the connecting column 201. In this embodiment, only D1 = 1.5 * D2 is used as an example, that is, the diameter of the shaping section 2 is 1.5 times the diameter of the connecting column 201. Of course, in other embodiments, it can also be 1.2 times, 1.6 times, or 1.8 times.

[0067] On the other hand, this embodiment further provides a riveting method, which uses an ultrasonic riveting device having the above-mentioned ultrasonic riveting welding head to perform riveting on the first metal member 100 and the second metal member 200. The riveting method includes the following steps:

[0068] S1. Sequentially stack the first metal member 100 and the second metal member 200 on the bottom mold 4 of the ultrasonic riveting equipment. Specifically, the second metal member 200 and the first metal member 100 are stacked on the bottom mold 4 from bottom to top, and the connecting column 201 on the second metal member 200 is plugged into the through hole 101 and extends out of the first metal member 100.

[0069] S2, driving the ultrasonic riveting welding head to move toward the connecting post 201 until the piercing section 1 penetrates into the interior of the connecting post 201. When the piercing section 1 penetrates into the interior of the connecting post 201 to a preset depth, the ultrasonic riveting welding device triggers ultrasonic welding.

[0070] It is understood that the conical piercing section 1 initially punctures the connecting post 201, causing the top end of the connecting post 201 to deform rapidly, while the piercing section 1 guides the plastic deformation of the connecting post 201. When the piercing section 1 penetrates the interior of the connecting post 201 to a predetermined depth, the ultrasonic generator and ultrasonic transducer of the ultrasonic riveting equipment are activated, transmitting high-frequency mechanical vibrations to the connecting post 201.

[0071] The specific ultrasonic welding parameters are as follows: set the energy to 200-2000 J, the power to 500-3000 W, the impedance to 1-10 Z, the amplitude to 10-30 μm, and the down force F to 500-2000 N.

[0072] S3. The ultrasonic riveting welding head transmits high-frequency mechanical vibration to the connecting post 201 and maintains it for a preset time until the connecting post 201 extends out of the material of the first metal component 100 and expands to form a locking structure.

[0073] As described above, by maintaining pressure for a predetermined period, the top of the connecting post 201 continuously deforms until an annular stopper 2012 is formed at the top of the connecting post 201. The stopper 2012 abuts against the first metal member 100, thereby preventing the first metal member 100 from separating from the second metal member 200 and achieving mechanical interlocking of the first and second metal members 100, 200. Using ultrasonic riveting equipment with an ultrasonic riveting head to directly rivet the first and second metal members 100, this is more cost-effective and efficient than the traditional process of mechanical riveting followed by laser welding.

[0074] Example 2

[0075] Reference Figures 3 to 5 The difference between this embodiment and embodiment 1 is that: the end of the connecting column 201 opposite to the ultrasonic riveting welding head has a connecting hole 2011, and the connecting hole 2011 is coaxially arranged with the connecting column 201; in this way, the continuous structure of the connecting column 201 can be destroyed, so that the top end of the connecting column 201 forms a thin-walled structure, the connecting column 201 is more susceptible to deformation, and the efficiency of riveting can be improved.

[0076] Optionally, in this embodiment, the depth of the connecting hole 2011 is T, and the wall thickness of the connecting column 201 corresponding to the connecting hole 2011 is t, T=1t~2t, and in this embodiment, T=1.5t, so that the wall thickness of the thin-walled structure at the top of the connecting column 201 can be guaranteed, while improving the efficiency of riveting and ensuring the strength of the rear limit portion 2012.

[0077] Furthermore, H2 = 0.7T to 1.1T, and preferably H2 = 0.8T in this embodiment. This allows the height of the connecting post 201 protruding from the first metal member 100 to be limited based on the depth of the connecting hole 2011, or the depth of the connecting hole 2011 to be limited based on the height of the connecting post 201 protruding from the first metal member 100, thereby ensuring the inherent strength of the connecting post 201. The diameter of the connecting hole 2011 is D3, and the diameter of the connecting post 201 is D2. D3 = 1 / 2*D2 to 3 / 4*D2, and preferably D3 = 2 / 3*D2 in this embodiment. This limits the diameter of the connecting hole 2011 based on the diameter of the connecting post 201 itself, allowing the top of the connecting post 201 to be easily deformed while maintaining a certain strength.

[0078] In the first aspect, the present embodiment provides an ultrasonic riveting welding head. The ultrasonic riveting welding head includes a connecting section, a shaping section 2, an insertion section 3 and a piercing section 1. The connecting section, the shaping section 2, the insertion section 3 and the piercing section 1 are arranged in sequence, and the connecting section is connected to the ultrasonic transducer of the ultrasonic riveting welding equipment. The piercing section 1 can penetrate the bottom of the connecting hole 2011 and guide the metal rivet (i.e., the connecting column 201) to undergo initial plastic deformation. The insertion section 3 has an outer diameter or outer profile that gradually increases from itself toward the connecting section, so as to abut against the inner wall of the connecting hole 2011 when the ultrasonic riveting welding head is vertically advanced by a transplanting mechanism and applies high-frequency mechanical vibration, thereby applying an initial force to the inner wall of the connecting hole 2011. The shaping section 2 is configured to further guide the material expansion of the connecting column 201 after the insertion section 3 is inserted into the connecting hole 2011 to form a locking structure.

[0079] As shown above, when the connecting column 201 is riveted, the insertion section 1 is inserted into the connecting hole 2011 and penetrates the bottom of the connecting hole 2011 to destroy the continuity structure of the connecting column 201 and guide the connecting column 201 to undergo initial plastic deformation. At the same time, the insertion section 3 is inserted into the preset connecting hole 2011 of the connecting column 201, and the outer wall of the insertion section 3 directly abuts the edge of the opening of the connecting hole 2011 and transmits high-frequency mechanical vibration, thereby causing the top of the connecting column 201 to rapidly expand and deform outward; the shaping section 2 further squeezes the connecting column 201 and guides the material at the top of the connecting column 201 to expand, ultimately forming a locking structure. In addition, the high-frequency shear vibration of the ultrasonic riveting head causes microscopic slippage of the contact surface, and the frictional heat softens the connecting column 201, making it easier for the connecting column 201 to expand and deform. When the temperature of the connecting column 201 reaches the recrystallization point of the material, the interface atoms diffuse to form a micro-area metallurgical bond, achieving riveting welding. Finally, after the connection pillar 201 is expanded and deformed, a tight metal bond is formed between the top surface of the first metal member 100 and the side wall of the through hole 101, while meeting the sealing, mechanical connection strength and electrical connection performance.

[0080] Optionally, the outer surface of the insertion section 3 is formed into a frustum, a spherical table, an arcuate convex surface, or a combination of multiple sections. In this embodiment, a frustum is taken as an example. Specifically, in this embodiment, the insertion section 3 is arranged in a frustum, and the diameter of the insertion section 3 gradually increases from bottom to top. The diameter of the bottom end of the insertion section 3 is smaller than the diameter of the connecting hole 2011, and the diameter of the top end of the insertion section 3 is larger than the diameter of the connecting hole 2011. Therefore, when the insertion section 1 abuts the side wall of the bottom of the connecting hole 2011 and moves downward, the outer wall of the insertion section 3 abuts the inner wall of the connecting hole 2011, directly squeezing the thin-walled area at the top of the connecting column 201 with relatively weak strength, causing the top of the connecting column 201 to deform rapidly, thereby reducing the operating pressure and improving the efficiency of riveting.

[0081] Optionally, the difference between the diameter of the connecting hole 2011 and the diameter of the bottom end of the insertion section 3 is 0.1 to 0.5 mm, that is, the diameter of the connecting hole 2011 is slightly larger than the diameter of the bottom end of the insertion section 3, thereby ensuring that the bottom end of the insertion section 3 can be smoothly inserted into the connecting hole 2011.

[0082] Furthermore, a transition zone 31 is formed at one end of the insertion section 3 adjacent to the piercing section 1. This transition zone 31 serves to limit the penetration depth of the piercing section 1 into the connecting column 201. Specifically, at the end of the insertion section 3 adjacent to the piercing section 1, the cross-sectional area of the insertion section 3 is greater than that of the piercing section 1, forming the transition zone 31 at the end of the insertion section 3. Specifically, the diameter of the bottom end of the insertion section 3 is greater than the diameter of the top end of the piercing section 1. This way, when the transition zone 31 abuts the bottom of the connecting hole 2011, the piercing section 1 cannot further enter the connecting column 201, thereby limiting the penetration depth of the piercing section 1.

[0083] In addition, when the height of the puncture segment 1 remains unchanged, that is, when the penetration depth of the puncture segment 1 remains unchanged, by appropriately reducing the diameter of the top end of the puncture segment 1, the angle of the tip of the puncture segment 1 can be kept within a smaller range to ensure the sharpness of the puncture segment 1, thereby ensuring the puncture effect of the puncture segment 1.

[0084] Furthermore, the transition zone 31 is always spaced apart from the bottom wall of the connecting hole 2011 (refer to Figure 5 ), thereby preventing the transition zone 31 from abutting against the bottom wall of the connecting hole 2011 before the connecting column 201 completes plastic deformation, so as to ensure that the vibration of the ultrasonic riveting welding head can effectively act on the shaping section 2 during the riveting process, thereby improving the shaping effect of the connecting column 201.

[0085] In addition, one end of the shaping section 2 adjacent to the insertion section 3 is formed into a flattening area 21, and the flattening area 21 has a pressing surface that is substantially perpendicular to the axis of the ultrasonic riveting welding head. The flattening area 21 is used to compact the top of the connecting column 201 after deformation. Specifically, the diameter of the top of the insertion section 3 is smaller than the diameter of the shaping section 2, so that the end of the shaping section 2 also forms a flattening area 21, and the flattening area 21 is arranged in an annular shape, thereby achieving final pressure and energy transfer through the annular flattening area 21. In addition, the adjacent portion of the insertion section 3 and the shaping section 2 also presents an arc-shaped transition, and the center of the arc is located outside the ultrasonic riveting welding head. It can be understood that the edge of the insertion section 3 adjacent to the flattening area 21 has a circular chamfer, so that an arc-shaped transition surface is formed between the outer periphery of the insertion section 3 and the flattening area 21, thereby plasticizing the top of the connecting column 201 through the arc surface.

[0086] On the other hand, the riveting method uses an ultrasonic riveting device having the ultrasonic riveting welding head to perform riveting on the first metal member 100 and the second metal member 200. The riveting method includes the following steps:

[0087] S1. Sequentially stack the first metal member 100 and the second metal member 200 on the bottom mold 4 of the ultrasonic riveting equipment, with the connecting posts 201 of the second metal member 200 pre-defined with connecting holes 2011. Specifically, the second metal member 200 and the first metal member 100 are stacked from bottom to top on the bottom mold 4, with the connecting posts 201 on the second metal member 200 plugging into the through holes 101 and extending out of the first metal member 100.

[0088] S2: Drive the ultrasonic riveting welding head toward the connecting column 201 until the insertion section 3 is inserted into the connecting hole 2011. When the insertion section 3 is inserted into the connecting hole 2011 to a preset depth, the ultrasonic riveting welding device triggers ultrasonic welding.

[0089] It is understood that the outer wall of the insertion section 3 initially squeezes the top of the connecting post 201, causing the top of the connecting post 201 to deform rapidly, while the insertion section 3 guides the plastic deformation of the connecting post 201. When the insertion section 3 reaches a predetermined depth in the connecting hole 2011, the ultrasonic generator and ultrasonic transducer of the ultrasonic riveting equipment are activated, transmitting high-frequency mechanical vibrations to the connecting post 201.

[0090] It should be noted that since the bottom end of the insertion section 3 is provided with the piercing section 1, when the insertion section 3 is inserted into the connecting hole 2011, the piercing section 1 will be inserted into the connecting hole 2011 before the insertion section 3 and penetrate into the bottom of the connecting hole 2011 to guide the connecting column 201 to undergo initial plastic deformation, thereby accelerating the deformation speed of the connecting column 201.

[0091] S3. The ultrasonic riveting welding head transmits high-frequency mechanical vibration to the connecting post 201 and maintains it for a preset time until the connecting post 201 extends out of the material of the first metal component 100 and expands to form a locking structure.

[0092] As described above, by maintaining pressure for a predetermined period, the top of the connecting post 201 continuously deforms until the top of the connecting post 201 quickly forms a stopper 2012 that abuts the first metal member 100, thereby achieving mechanical interlocking of the first metal member 100 and the second metal member 200. Ultrasonic riveting equipment with an ultrasonic riveting head is used to directly and quickly rivet the first and second metal members 100, further improving the efficiency of the riveting.

[0093] Example 3

[0094] Reference Figure 6 and Figure 7 This embodiment differs from the second embodiment in that the insertion section 1 is not provided in this embodiment, and the outer surface of the insertion section 3 is formed into a spherical table. Specifically, the insertion section 3 is configured in the form of a spherical table (a three-dimensional portion formed by intercepting a sphere or hemisphere by two parallel planes), with the small end of the table facing the connecting post 201. When the ultrasonic riveting welding head is axially advanced and applies high-frequency mechanical vibration, it abuts against the inner wall of the connecting hole 2011, applying an initial force to the inner wall of the connecting hole 2011. The shaping section 2 then further compresses the connecting post 201 and guides the material at the top of the connecting post 201 to expand, ultimately forming a locking structure.

[0095] It is worth noting that the outer surface of the spherical table surface on the insertion section 3 expands outward, so that the top end of the connecting column 201 expands as much as possible after deformation, so as to increase the area of the deformed part of the connecting column 201 (that is, the limiting part 2012) acting on the surface of the first metal part 100, thereby ensuring the limiting effect on the first metal part 100. It is mainly suitable for scenarios where the diameter of the connecting hole 2011 is less than two-thirds of the diameter of the cylinder, that is, the scenario where D3 is less than 2 / 3*D2.

[0096] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Ultrasonic riveting welding head, used to connect to the acoustic component and perform ultrasonic riveting on metal riveted parts, characterized in that: The ultrasonic riveting welding head includes: a connecting section for connecting to an acoustic component to transmit high-frequency mechanical vibrations; A piercing section (1) is provided at the distal end of the connecting section, wherein the piercing section (1) has an outer diameter or outer profile that gradually increases from the piercing section itself toward the connecting section, so that when the ultrasonic riveting welding head is axially advanced and high-frequency mechanical vibration is applied, the piercing section (1) can penetrate the metal riveted part and guide the metal riveted part to undergo initial plastic deformation; and The shaping section (2) is adjacent to the piercing section (1), and the shaping section (2) is configured to further guide the material of the metal rivet to expand after the piercing section (1) pierces the metal rivet to form a locking structure.

2. The ultrasonic riveting welding head according to claim 1, characterized in that: The piercing section (1) is formed into a cone or wedge shape so that the piercing section (1) forms point contact or line contact with the surface to be processed of the metal riveted part.

3. The ultrasonic riveting welding head according to claim 1, characterized in that: One end of the shaping section (2) adjacent to the piercing section (1) is formed into a flattening area (21), and the flattening area (21) has a pressing surface perpendicular to the axis of the ultrasonic riveting welding head. The flattening area (21) is used to compact the top of the metal riveted part after it is deformed.

4. The ultrasonic riveting welding head according to claim 3, characterized in that: The junction between the piercing section (1) and the shaping section (2) is in an arc-shaped transition.

5. An ultrasonic riveting welding head, used for connecting to an acoustic component and ultrasonically riveting a metal riveted part having a preset connection hole (2011), characterized in that: The ultrasonic riveting welding head includes: a connecting section for connecting to an acoustic component to transmit high-frequency mechanical vibrations; an insertion section (3) disposed at the distal end of the connecting section, the insertion section (3) having an outer diameter or outer profile that gradually increases from the insertion section toward the connecting section, so as to abut against the inner wall of the connecting hole (2011) when the ultrasonic riveting welding head is axially advanced and applies high-frequency mechanical vibration, thereby applying an initial force to the inner wall of the connecting hole (2011); and The shaping section (2) is adjacent to the insertion section (3), and the shaping section (2) is configured to further guide the material of the metal rivet to expand after the insertion section (3) is inserted into the connection hole (2011) to form a locking structure.

6. The ultrasonic riveting welding head according to claim 5, characterized in that: The ultrasonic riveting welding head also includes: The piercing section (1) is adjacent to the end of the insertion section (3) facing away from the shaping section (2), and the piercing section (1) can penetrate the bottom of the connecting hole (2011) and guide the metal rivet to undergo initial plastic deformation.

7. The ultrasonic riveting welding head according to claim 6, characterized in that: One end of the insertion section (3) adjacent to the piercing section (1) is formed into a transition zone (31), and the transition zone (31) is used to limit the depth of the piercing section (1) piercing into the connecting hole (2011).

8. The ultrasonic riveting welding head according to claim 7, characterized in that: The outer surface of the insertion section (3) is formed into a frustum, a spherical table, an arcuate convex surface or a multi-section combined surface.

9. The ultrasonic riveting welding head according to claim 5, characterized in that: One end of the shaping section (2) adjacent to the insertion section (3) is formed into a flattening area (21), and the flattening area (21) has a pressing surface perpendicular to the axis of the ultrasonic riveting welding head. The flattening area (21) is used to compact the top of the metal riveted part after it is deformed.

10. Ultrasonic riveting equipment, comprising a bottom die (4) for supporting a metal riveted part, characterized in that: It also comprises an ultrasonic riveting welding head according to any one of claims 1 to 4 or any one of claims 5 to 9, wherein the ultrasonic riveting welding head is driven by a transfer mechanism and is used to act on a metal riveted part placed on the bottom mold (4).

11. Riveting welding method, characterized in that: The ultrasonic riveting welding device having the ultrasonic riveting welding head according to any one of claims 1 to 4 is used, and the method comprises the following steps: A first metal part (100) and a second metal part (200) are sequentially stacked on a bottom mold (4) of an ultrasonic riveting device; wherein the first metal part (100) is located above the second metal part (200), a through hole (101) is provided on the first metal part (100), and a connecting column (201) penetrating the through hole (101) is connected to the second metal part (200); The ultrasonic riveting welding head is driven to move toward the connecting column (201) until the piercing section (1) penetrates into the interior of the connecting column (201); when the depth of the piercing section (1) penetrating the connecting column (201) reaches a preset depth, the ultrasonic riveting welding device triggers ultrasonic welding; The ultrasonic riveting welding head transmits high-frequency mechanical vibration to the connecting column (201) and maintains it for a preset time until the connecting column (201) extends out of the material of the first metal part (100) to form a locking structure.

12. Riveting method, characterized in that: The ultrasonic riveting welding device having the ultrasonic riveting welding head according to any one of claims 5 to 9 is used, and the method comprises the following steps: A first metal part (100) and a second metal part (200) are sequentially stacked on a bottom mold (4) of an ultrasonic riveting device; wherein the first metal part (100) is located above the second metal part (200); a through hole (101) is provided on the first metal part (100); a connecting column (201) penetrating the through hole (101) is connected to the second metal part (200); and a connecting hole (2011) is preset at the top of the connecting column (201); The ultrasonic riveting welding head is driven to move toward the connecting column (201) until the insertion section (3) is inserted into the interior of the connecting hole (2011); when the insertion section (3) abuts against the inner wall of the connecting hole (2011), the ultrasonic riveting welding device triggers ultrasonic welding; The ultrasonic riveting welding head transmits high-frequency mechanical vibration to the connecting column (201) and maintains the vibration for a preset time until the material of the connecting column (201) at the position of the connecting hole (2011) is expanded to form a locking structure.

Images