Patent Application
20250187060
This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0177522 filed in the Korean Intellectual Property Office on Dec. 8, 2023, the entire contents of which are incorporated herein by reference.
Embodiments of the present disclosure relate to a method of manufacturing a vehicle body component, and more particularly, to a method of manufacturing a vehicle body component, which produces a tubular vehicle body component.
In general, vehicle body components having closed cross-sections are applied to a vehicle body to protect a passenger from a collision. The vehicle body components having the closed cross-sections may be manufactured by joining a plurality of panels, each of which is formed in a preset shape, by using welding or a bonding agent for a structure.
However, this method of producing the vehicle body components may increase mold costs, joining costs, and production cycle time.
In order to solve the above-mentioned problems, recently, vehicle body components having the closed cross-sections have been manufactured by using pipes. Alternatively, the vehicle body components having the closed cross-sections have been manufactured by performing a roll-forming process on panel materials.
Meanwhile, recently, future mobility visions with new concepts for implementing human-oriented dynamic future cities have been introduced in vehicle industries. One of the future mobility solutions is a purpose-built vehicle (PBV) as a purpose-based mobility vehicle.
Examples of the PBV may include an environmental-friendly movable vehicle based on an electric vehicle (EV). The PBVs may provide various customized services to users while the PBVs move from starting points to destinations in an unmanned or manned autonomous driving manner. Therefore, the PBVs are being manufactured to have various shapes and sizes depending on the type of customized service.
Vehicle bodies of the PBVs adopt tubular vehicle body components having closed cross-sections to ensure expandability of various shapes and sizes and advantageously produce vehicle bodies various types of vehicles with a small number of components.
Therefore, studies are being conducted on methods of manufacturing tubular vehicle body components having various shapes and sizes.
The above information disclosed in this Background section is only to enhance understanding of the background of the disclosure. Therefore, the Background section may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
The present disclosure provides a method of manufacturing a vehicle body component. The method is capable of improving a degree of design freedom of vehicle body components such as a flange-integrated tube, i.e., a tube shaped body component with an integrated flange.
A method of manufacturing a vehicle body component in the form of a flange-integrated tube is provided according to an embodiment of the present disclosure. The method may include step (a) of forming a pipe material having a closed cross-section with a preset shape, The method may also include step (b) of cold-forming at least one flange on the pipe material for form a flange formed material. The method may also include step (c) of performing hydroforming on the flange formed material having the at least one flange by using liquid pressure.
In addition, a method of manufacturing a vehicle body component according to an embodiment of the present disclosure may further include step (d) of heating a molded product, on which the hydroforming is performed, to a preset temperature in a heating furnace. The method may also include step (e) of rapidly cooling the heated molded product in a water tub.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, the strength of the molded product, which has been subjected to steps (a)-(c), may be 60 K or less.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, the strength of the molded product, which has been subjected to steps (a)-(e), may be 100 to 150 K.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, in step (a), the pipe material having a non-circular closed cross-section may be formed by pultrusion from a pipe source material subjected to pipe-making forming to have a circular closed cross-section.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, in step (a), the pipe material having a non-circular closed cross-section may be formed by bending a blank material by a press forming process.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, in step (a), the pipe material may be bent at a preset curvature.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, in step (b), the pipe material having a non-circular closed cross-section may be seated on a press mold and the pipe material may be cold-formed by the press mold.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, in step (c), the flange forming material may be expanded and formed by a preset hydraulic pressure in a hydroforming mold.
In addition, in a method of manufacturing a vehicle body component according to an embodiment of the present disclosure, trimming and piercing may be performed on the molded product.
According to an embodiment of the present disclosure, it is possible to improve the degree of design freedom of the vehicle body component, such as the flange-integrated tube. It is also possible to optimize the cross-sectional shape.
Other effects, which may be obtained or expected by the embodiments of the present disclosure, are directly or implicitly disclosed in the detailed description of the embodiments of the present disclosure. That is to say, various effects expected according to the embodiments of the present disclosure are disclosed in the detailed description below.
Because the drawings are provided for reference to describe embodiments of the present disclosure, the technical spirit of the present disclosure should not be construed as being limited to the accompanying drawings.
It should be understood that the accompanying drawings are not necessarily drawn to scale. The drawings provide a somewhat simplified representation of various features that exemplify the basic principles of the present disclosure. For example, specific design features of the present disclosure, including particular dimensions, directions, positions, and shapes, will be partially determined by the particularly intended application and use environment.
Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings so that those with ordinary skill in the art to which the present disclosure pertains may carry out the embodiments. However, the present disclosure may be implemented in various different ways and is not limited to the embodiments described herein.
The terms used herein are merely for the purpose of describing a specific embodiment, and not intended to limit the present disclosure. The singular expressions used herein are intended to include the plural expressions unless the context clearly dictates otherwise.
It is to be understood that the term “comprise (include)” and/or “comprising (including)” used in the present specification means that the features, the integers, the steps, the operations, the constituent elements, and/or the components are present. However, the presence or addition of one or more other features, integers, steps, operations, constituent elements, components, and/or groups thereof is not excluded.
The terms ‘vehicle’, ‘for a vehicle’, and ‘automobile’ or the similar terms used in the present specification generally include vehicles. Such vehicles may include passenger vehicles, sport utility vehicles (SUVs), buses, trucks, and various commercially available vehicles. Such vehicles may also include hybrid vehicles, electric vehicles, hybrid electric vehicles, purpose built vehicles (PBVs) based on electric vehicles, hydrogen power vehicles, and other alternative fuel vehicles (e.g., fuel induced from resources other than petroleum).
Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. When a component, device, element, or the like of the present disclosure is described as having a purpose or performing an operation, function, or the like, the component, device, or element should be considered herein as being “configured to” meet that purpose or perform that operation or function.
With reference to
In this case, examples of the vehicle body may include a vehicle body of a purpose-built mobility vehicle (hereinafter, referred to as a ‘PBV’).
The vehicle body of the PBV is manufactured to have a structure capable of reducing the number and weight of components and manufactured to have various shapes and sizes.
Furthermore, examples of the vehicle body component may include closed cross-section components made by joining panels by using welding or a bonding agent and may include a hybrid vehicle body with a combination of tubular closed cross-section components.
The method of manufacturing a vehicle body component according to an embodiment of the present disclosure may be applied to manufacture the tubular vehicle body component 1 applicable to the hybrid vehicle body.
Furthermore, the method of manufacturing a vehicle body component according to an embodiment of the present disclosure may be applied to manufacture a flange-integrated tube, i.e., a tubular shaped component with an integrated flange, as the vehicle body component 1. The component 1 may have at least one flange 3 integrally formed with the component, and a closed cross-section 5 having a preset shape.
However, it should not be understood that the scope of protection of the present disclosure is not limited to manufacturing of a vehicle body component. The technical spirit of the present disclosure may be applied as long as the component is a tubular component applicable to frames with various types and for various purposes in addition to the vehicle body.
In one embodiment, the vehicle body component 1 may include a bent portion 7 bent at a preset planar curvature, and at least one piercing hole 9.
With reference to
In this case, the method of manufacturing a vehicle body component according to an embodiment of the present disclosure may include pre-processing steps or processes described below that are performed before the above-mentioned steps are performed.
The pre-processing steps or processes may include a process of designing the vehicle body component 1 (see
In addition, the pre-processing steps or processes may include a process of performing a forming analysis on the vehicle body component 1 on the basis of the layout of the forming facilities and may include a process of manufacturing the forming facilities by designing the forming facilities, creating NC data, and performing machining on the basis of the forming analysis result.
Hereinafter, the steps of a method of manufacturing a vehicle body component according to an embodiment of the present disclosure is described in detail with reference to the accompanying drawings.
With reference to
The pipe material forming step S1 is described in accordance with each embodiment. First, in one embodiment, as illustrated in
Next, in one embodiment, the pipe material 10 having a non-circular closed cross-section 11 is manufactured by performing pultrusion on the pipe source material 14 by means of a pultrusion apparatus 15.
As illustrated in
For example, the pipe material 10 may include a polygonal closed cross-section 11.
Furthermore, other embodiments may each include a process of bending the pipe material 10 at a preset planar curvature by means of a bending machine 18.
After the above-mentioned processes, the flange forming step S2 is performed. As illustrated in
In the flange forming step S2, the pipe material 10, which is seated on a lower mold of a press mold 22, is cold-formed by an upper mold, and the flange formed material 20 having at least one flange 3 may be formed from the pipe material 10.
For example, at least one flange 3 may be formed by cam forming units provided on the lower and upper molds. In the embodiment shown in the drawings, the flange formed material 20 is created having two flanges 3.
In this case, because the pipe material 10 has the polygonal closed cross-section 11, the seating properties of the press mold 22 may be ensured.
Next, the hydroforming step S3 is performed. As illustrated in
In the hydroforming step S3, the flange formed material 20 is seated on a hydroforming mold 31 and may be expanded and formed by a hydraulic pressure.
As is well known to those of ordinary skill in the art, the hydroforming mold 31 may include a lower mold, an upper mold, two pressure intensifiers, and a punch.
In this case, the molded product 30, which is manufactured by being subjected to the pipe material forming step S1, the flange forming step S2, and the hydroforming step S3, has a ferrite structure. The strength of the molded product 30 may be 60 K or less.
Meanwhile, a method of manufacturing a vehicle body component according to and embodiment of the present disclosure performs the heat treatment step S4 and the cooling step S5, which are described below, so that the molded product 30 has a martensite structure with high strength.
As illustrated in
In this case, the molded product 30 may be loaded into the heating furnace 41 by a robot. Further, the heating furnace 41 includes a heating furnace base 43 on which the molded product 30 is seated. As an example, the heating furnace base 43 may be implemented as a drawer type structure.
Furthermore, the heating furnace 41 may heat the molded product 30 to a high temperature (e.g., 900° C. or more) equal to or higher than a transformation point temperature by using heat generated by a plurality of heaters 45.
Therefore, a metal structure of the molded product 30 may change from a ferrite structure to an austenite structure.
Next, as illustrated in
In this case, the molded product 30 may be loaded into the water tub 51 by a robot. The water tub 51 includes a water tub base 53 that may move in an upward/downward direction. As an example, the water tub base 53 may be implemented as a drawer type structure.
Further, in a state in which the molded product 30 is seated on the water tub base 53, the water tub base 53 moves downward, such that the molded product 30 may be cooled directly by a coolant in the water tub 51.
Therefore, as the molded product 30 is rapidly cooled in the water tub 51, the molded product 30 has a martensite structure of about 100 to 150 K.
The molded product 30 manufactured as described above is subjected to the trimming step S6 and the piercing step S7, such that the vehicle body component 1, i.e., the finally molded product may be manufactured, as illustrated in
In this case, as illustrated in
Further, as illustrated in
Hereinafter, the effect of a method of manufacturing a vehicle body component according to an embodiment of the present disclosure is described with reference to a comparison with a comparative example.
First, a method of manufacturing a flange-integrated tube according to the comparative example includes a process of forming a flange in a state in which a pipe material having a circular cross-section is electrically heated in a single mold, performing hydroforming by using a pneumatic pressure, and cooling the flange by using a coolant flowing along a cooling channel. This method of manufacturing the flange-integrated tube by the above-mentioned processes is typically referred to as a ‘STAF process method’ in the art.
In contrast, the method of manufacturing a vehicle body component according to the embodiment of the present disclosure may form at least one flange 3 by cold-forming the pipe material 10 having the non-circular closed cross-section 11.
Therefore, because a method of manufacturing a vehicle body component according to an embodiment of the present disclosure cold-forms at least one flange 3 on the pipe material 10 having the non-circular closed cross-section 11, it is possible to ensure the mold seating properties of the pipe material 10, unlike the comparative example that forms the flange on the pipe material having a circular cross-section.
In addition, because the comparative example forms the flange by electrically heating the pipe material having a circular cross-section, non-uniform electrical application to the pipe material may be caused by a constraint such as a bending curvature numerical value of the pipe material. Therefore, because it is impossible to electrically heat the overall pipe, a degree of design freedom of the molded product may deteriorate.
Furthermore, a method of manufacturing a vehicle body component according to an embodiment of the present disclosure performs the hydroforming on the flange formed material 20 by the hydroforming mold 31 by using hydraulic pressure. However, the comparative example performs hydroforming on the material having the flange by using pneumatic pressure.
Therefore, because the hydraulic pressure is about at least 10 times higher than the pneumatic pressure, the method of manufacturing a vehicle body component according to the embodiment of the present disclosure may implement a corner portion 6 (see
If hydroforming is performed by hydraulic pressure in the comparative example, the electrically heated material is rapidly cooled, and the strength of the material increases, which makes it impossible to implement a shape of the final product.
While embodiments of the present disclosure have been described above, the present disclosure is not limited thereto. Various modifications can be made and carried out within the scope of the claims, the detailed description of the disclosure, and the accompanying drawings, and also fall within the scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0177522 | Dec 2023 | KR | national |
