KR-20260062487-A - Bonding element for FEW and method for bonding dissimilar materials using the same

Abstract

The present invention relates to a bonding element for FEW and a method for bonding dissimilar materials using the same, and more specifically, to a stud hardware for FEW (Friction Element Welding) comprising: a body portion configured to bond dissimilar materials by melting and fusing them by rotational friction heat; a head portion integrally formed on the upper part of the body portion and configured to be fitted into a drive bit of a friction bonding device to rotate the body portion; and a stud portion integrally formed on the upper part of the head portion; and a stud socket coupled to the drive bit of the friction bonding device, having a receiving portion formed to insert the stud portion and configured to fit the head portion.

Inventors

• 이우람
• 박지형

Assignees

• 현대제철 주식회사

Dates

Publication Date

20260507

Application Date

20241029

Claims (8)

1. A stud hardware for FEW (Friction Element Welding) comprising: a body portion configured to join dissimilar materials by melting and fusing them by rotational friction heat; a head portion integrally formed on the upper part of the body portion and configured to be fitted into a drive bit of a friction joining device to rotate the body portion; and a stud portion integrally formed on the upper part of the head portion; and A stud socket coupled to the drive bit of the friction joining device, having a receiving portion formed for inserting the stud portion and configured to accommodate the head portion; Joining element for FEW.
2. In Article 1, The above stud socket is, The above receiving portion is formed in the lower center, and Characterized by having a contact portion formed on the lower surface where the above-mentioned receiving portion is formed, which is in close contact with the head portion of the stud hardware. Joining element for FEW.
3. In Paragraph 2, The above stud socket is A first engagement portion is formed on at least a part of the above-mentioned contact portion, and The above stud hardware is, Characterized by having a second engagement portion formed on at least a part of the head portion that engages with the first engagement portion. Joining element for FEW.
4. In Paragraph 3, The above stud socket is, A first meshing portion is formed along the outer edge of the above-mentioned contact portion, and The above stud hardware is, Characterized by having a second meshing portion formed on the edge of the head portion that engages with the first meshing portion. Joining element for FEW.
5. In Paragraph 3, The above stud hardware is, The second interlocking portion is formed to surround the stud portion at the center of the head portion, and The above stud socket is Characterized by the above-mentioned contact portion being formed to be fitted into the above-mentioned second fitting portion as a first fitting portion. Joining element for FEW.
6. In Paragraph 5, The above head part is, Characterized by being formed in a shape that extends upward from the above body part. Joining element for FEW.
7. A welding element preparation step of inserting FEW (Friction Element Welding) stud hardware, having a stud portion formed therein, into a stud socket configured in a drive bit of a friction joining device and having a receiving portion formed therein; A non-metal penetration step in which the body portion of the stud hardware penetrates a non-metal material among target materials while rotating the drive bit; and A metal welding step comprising welding the body portion of the stud hardware to the metal material among the above target materials by rotational friction; Heterogeneous material joining method using a joining element for FEW.
8. In Article 7, The above welding element preparation step is, A stud insertion step of inserting a stud portion of the stud hardware into a receiving portion of the stud socket; and Characterized by including a mating step of fitting the second mating portion of the stud hardware into the first mating portion of the stud socket so as to be engaged. Heterogeneous material joining method using a joining element for FEW.

Description

Bonding element for FEW and method for bonding dissimilar materials using the same The present invention relates to a bonding element for FEW and a method for bonding dissimilar materials using the same, and more specifically, to a Friction Element Welding (FEW) capable of installing studs. In the automotive industry, the application of ultra-high-strength steel and non-ferrous metals is on the rise, as performance is required to ensure crash safety for passenger protection and compliance with crash regulations, in addition to the lightweighting of vehicle bodies to meet environmental regulations. For example, the use of ultra-high-strength steel is increasing in key components for passenger safety, such as center pillars, front pillars, side sills, and roof rails, to protect passengers by minimizing deformation during a collision. In addition, to reduce the weight of the vehicle body, other components are made of non-metallic lightweight materials such as aluminum and CFRP. Therefore, in automobile manufacturing, it is very important to secure technology for joining dissimilar materials, such as ultra-high-strength steel and non-metallic lightweight materials. FEW (Friction Element Welding) is a method of joining two laminated materials without pilot holes, and is used as one of the methods for joining non-metallic lightweight materials and ultra-high strength steel. Specifically, when hardware (elements, rivets) is applied and rotated on the upper surface of a heterogeneous material in which a non-metallic lightweight material is laminated on top of ultra-high strength steel, the hardware penetrates the top plate, which is the non-metallic lightweight material, and the penetration stops at the surface of the ultra-high strength steel. At this time, frictional heat is generated between the ultra-high strength steel and the hardware due to the rotation of the hardware, causing it to melt. When the hardware is fused to the ultra-high strength steel while being pressurized, dissimilar materials of non-metallic lightweight materials and ultra-high strength steel can be joined. Meanwhile, stud welding is a welding method in which a stud is welded vertically to a base material, and the weld area is melted using heat and then fused by applying pressure. Methods such as arc welding and gas seal welding are used. Stud welding is primarily used to join various parts to a base material. It is suitable for mass production due to its speed and high efficiency, and is widely used in various industrial fields because it guarantees a consistent level of welding quality regardless of operator skill. Furthermore, it is a highly flexible welding method that can be easily applied to various materials and thicknesses. However, since stud welding is a method of welding a metal stud to a metal base material, as explained above, when a non-metallic lightweight material is joined to ultra-high strength steel by FEW, there is a problem that stud welding cannot be applied because the surface of that part is a non-metallic lightweight material. Consequently, while the joining of dissimilar materials is essential to meet environmental regulations, safety standards, and crash safety regulations in the automotive industry, this presents a problem in that it imposes restrictions on the use of stud welding to join automotive parts. Related technologies include the following prior art documents: Korean Published Patent Application No. 10-2023-014619, 'Element, friction element joining method and friction element joining joint manufacturing method' and Korean Published Patent Application No. 10-2023-0137468, 'Element for friction joining'; however, these prior art documents relate to FEW and do not contain content regarding stud welding. FIG. 1 is a schematic diagram showing one embodiment of a bonding element for FEW according to the present invention. FIG. 2 is a configuration diagram showing another embodiment of FIG. 1. Figure 3 is a drawing illustrating the state in which the configuration of Figure 2 is fitted. FIGS. 4 and FIGS. 5 are configuration diagrams showing another embodiment of FIG. 1. FIG. 6 is a flowchart showing an embodiment of a heterogeneous material joining method using a joining element for FEW according to the present invention. FIG. 7 is a flowchart illustrating a specific example of step 'S100' of FIG. 6. Figures 8 and 9 are drawings illustrating the process of performing Figure 6 using Figure 4. Examples of the bonding element for FEW and the method for bonding dissimilar materials using the same according to the present invention can be applied in various ways, and below, the most preferred embodiment will be described with reference to the attached drawings. FIG. 1 is a schematic diagram showing one embodiment of a bonding element for FEW according to the present invention. Referring to FIG. 1, the joining element for FEW includes stud hardware (100) and a stud socket (200). The stud hardware (100) is intended f