Vehicle side rail and vehicle body frame unit including same

Abstract

An embodiment of the present invention provides a vehicle side rail that is disposed at the upper end of a vehicle body frame unit and supports a roof. The vehicle side rail includes: an inner member including a first flange that protrudes outward from one end and has a first length; and an outer member including a second flange that protrudes outward from one end, faces the first flange, and has a second length different from the first length, wherein the inner member and the outer member are coupled in a state in which the first flange and the second flange are in contact with each other, thus forming a closed cross-section, and the closed cross-section extends along the extension direction of the side rail while maintaining the same cross-sectional area. At least one of the first flange or the second flange includes, at one end, a bent portion that is bent in a bending direction inclined relative to the extension direction.

Description

Vehicle side rail and vehicle body frame unit including the same

[0001] The present invention relates to a vehicle side rail and a vehicle body frame unit including the same.

[0002] Generally, the side reinforcement structure of the vehicle body is formed by including a side rail reinforcement positioned on the upper part of the vehicle body, an A-pillar reinforcement positioned vertically in front of the front door of the vehicle body, a B-pillar reinforcement positioned vertically in the center to separate the front door and the rear door of the vehicle body, a C-pillar reinforcement positioned vertically behind the rear door, and a side sill outer positioned on the lower part of the vehicle body, thereby providing structural rigidity to the upper, lower, and side parts of the vehicle body.

[0003] At this time, side body reinforcements such as side rails are manufactured by separately producing inner and outer parts and combining them; however, there is an increasing need for side rails that can change shape to accommodate various vehicle forms, are suitable for mass production, reduce manufacturing costs, and ensure structural rigidity.

[0004] The present invention was devised to solve the above-mentioned problems and aims to provide a vehicle side rail and a vehicle body frame unit including the same, which are easy to manufacture and assemble, making them advantageous for mass production, and simultaneously capable of lowering manufacturing costs.

[0005] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall contents of this specification.

[0006] To achieve the above objectives, a vehicle side rail according to one embodiment of the present invention is a vehicle side rail that supports a roof and is disposed on the upper part of a vehicle body frame unit, and comprises an inner member including a first flange having a first length that protrudes outward from one end and has a first length, and an outer member including a second flange that protrudes outward from one end and has a second length different from the first length that faces the first flange and has a second length different from the first length. The inner member and the outer member are joined so that the first flange and the second flange are in contact with each other to form a closed cross-section, and the closed cross-section extends with the same area along the extension direction of the side rail, and at least one of the first flange and the second flange may include a bending portion at one end that is bent in a bending direction inclined with respect to the extension direction.

[0007] In an embodiment of the present invention, the first flange and the second flange are provided in pairs, and the two first flanges are respectively positioned at the upper and lower portions of the inner member, and the two second flanges are respectively positioned at the upper and lower portions of the outer member so as to face the first flange in a one-to-one manner.

[0008] In an embodiment of the present invention, when the inner member and the outer member are combined, a first area in which the first flange and the second flange are arranged together so as to overlap, and a second area in which only one of the first flange and the second flange is arranged may be formed.

[0009] In an embodiment of the present invention, the second region may have a longer length than the first region.

[0010] In an embodiment of the present invention, the bending portion may be disposed in the second region disposed at the upper end of the inner member or the outer member.

[0011] In an embodiment of the present invention, the inner member includes a first bend portion disposed at the upper end of the inner member and bent in the bending direction, and the outer member may include a second bend portion disposed at the upper end of the outer member and bent in the bending direction, having a length different from that of the first bend portion.

[0012] In an embodiment of the present invention, when the inner member and the outer member are combined, a first region in which the first bending portion and the second bending portion are arranged together so as to overlap, and a second region in which only one of the first bending portion and the second bending portion is arranged may be formed.

[0013] In an embodiment of the present invention, the length of the first region may be 2 to 7 mm.

[0014] In an embodiment of the present invention, the length of the second region may be 10 to 15 mm.

[0015] In an embodiment of the present invention, the first flange and the second flange are joined in the first region by a first joining method, and in the second region, at least one of a roof panel and a side outer can be joined using a second joining method.

[0016] In an embodiment of the present invention, one end is coupled to the second region formed on either side of the inner member or the outer member, and the other end is coupled to the second region formed on the other side of the inner member or the outer member, so as to cover the outer side of the side rail.

[0017] In an embodiment of the present invention, the first joining method may be a laser welding method, and the second joining method may be a spot welding method.

[0018] A vehicle body frame unit according to one embodiment of the present invention may include a side rail according to any one of claims 1 to 12 which is disposed on the side of the vehicle body and supports a roof, a side sill disposed below the side rail and supporting the lower part of the vehicle body, and a pillar portion disposed between the side rail and the side sill and including a plurality of pillars.

[0019] The vehicle side rail and the vehicle body frame unit including the same according to the embodiments of the present invention can prevent welding defects and strength reduction caused by excessively overlapping welds by minimizing the number of welding layers when manufacturing the side rail and when combining additional parts such as side outers with the side rail, while ensuring sufficient strength and reducing the overall weight of the side rail.

[0020] In addition, when manufacturing a vehicle body, changes in the shape of the side rail can be easily implemented in response to various shapes of the vehicle body, thereby ensuring improved productivity and cost reduction during mass production of the vehicle body or side rail.

[0021] FIG. 1 is a side view illustrating a vehicle body frame unit according to one embodiment of the present invention.

[0022] FIG. 2 is a side view illustrating a vehicle side rail according to one embodiment of the present invention.

[0023] FIG. 3(a) is a cross-sectional view showing the front side rail constituting the side rail of FIG. 2 as viewed from the I-I' direction, and FIG. 4(b) is a cross-sectional view showing the rear side rail constituting the side rail of FIG. 2 as viewed from the II-II' direction.

[0024] FIG. 4 is a cross-sectional view showing one additional part attached to a vehicle side rail as viewed from the I-I' direction or the II-II' direction of FIG. 1.

[0025] FIG. 5 is a cross-sectional view showing two additional parts combined on a vehicle side rail as viewed from the I-I' direction or the II-II' direction of FIG. 1.

[0026] FIG. 6(a) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the I-I' direction of FIG. 1 or FIG. 2, and FIG. 6(b) is a cross-sectional view showing a side rail according to yet another embodiment of the present invention as viewed from the I-I' direction of FIG. 1 or FIG. 2.

[0027] FIG. 7(a) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the I-I' direction of FIG. 1 or FIG. 2, and FIG. 7(b) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the I-I' direction of FIG. 1 or FIG. 2.

[0028] FIG. 8(a) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the I-I' direction of FIG. 1 or FIG. 2, and FIG. 8(b) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the I-I' direction of FIG. 1 or FIG. 2.

[0029] Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0030] In addition, embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field.

[0031] In drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0032] In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form.

[0033] In this description, expressions such as “include” or “equipped” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0034] Unless otherwise specifically defined in the specification of the present invention, % units mean weight %.

[0035] In this specification, terms such as 'top', 'upper', 'upper surface', 'lower', 'lower surface', 'lower surface', and 'side surface' are based on the drawings and may actually vary depending on the direction in which the elements or components are arranged.

[0036] Additionally, throughout the specification, when it is said that one part is 'connected' to another part, this includes not only cases where they are 'directly connected,' but also cases where they are 'indirectly connected' with other elements in between.

[0037] The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0038] The present invention will be described in detail below through examples. However, it should be noted that the examples described below are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0039] FIG. 1 is a side view illustrating a vehicle body frame unit according to one embodiment of the present invention.

[0040] Referring to FIG. 1, the body frame unit (10) is a skeletal body that supports the side of a vehicle (not shown) and can be formed by connecting a plurality of frames. At this time, the body frame unit (10) may include a side rail (RS), a side sill (SS), and a pillar (PL).

[0041] Side rails (RS) may be positioned on both sides of a floor panel (not shown) in the vehicle body section. Side rails (RS) serve as roof side rails, supporting the side sections of the vehicle's roof and maintaining the upper rigidity of the vehicle body.

[0042] The side rail (RS) may include a front side rail (SR1) and a rear side rail (SR2). Based on the front-rear direction of the vehicle (e.g., the X-axis direction of the drawing), the front side rail (SR1) may support the front portions of both sides of the vehicle's roof, and the rear side rail (SR2) may support the rear portions of both sides of the roof. At this time, the specific features of the side rail (RS) will be explained in detail below.

[0043] A side sill (SS) is installed at the lower part of a vehicle body or a vehicle body frame unit (10) to extend along the front-rear direction of the vehicle (e.g., X-axis direction) and can perform the function of maintaining the lower rigidity of the vehicle body. Such a side sill (SS) can be positioned opposite a side rail (RS) along the vertical direction (Z).

[0044] A pillar section (PL) is positioned between the side rail (RS) and the side sill (SS) to support the roof of the vehicle. At this time, the pillar section (PL) may include a plurality of pillars.

[0045] For example, the pillar section (PL) may include a vehicle A-pillar (hereinafter, A-pillar) (100), a vehicle B-pillar (hereinafter, B-pillar) (200), and a vehicle C-pillar (hereinafter, C-pillar) (300). The A-pillar (100), B-pillar (200), and C-pillar (300) may be spaced apart along the front-rear direction (X) between the side rail (RS) and the side sill (SS).

[0046] In this case, the upper portion of the A-pillar (100) may be connected to the lower portion of the front side rail (SR1) by the first upper connecting member (Cb11), and the lower portion of the A-pillar (100) may be connected to the front portion of the side sill (SS) by the first lower connecting member (Cb21). Similarly, the upper portion of the B-pillar (200) may be connected to the front lower portion of the rear side rail (SR1) by the second upper connecting member (Cb12), and the lower portion of the B-pillar (200) may be connected to the middle portion of the side sill (SS) by the second lower connecting member (Cb22). Furthermore, the upper portion of the C-pillar (300) may be connected to the rear lower portion of the rear side rail (SR2) by the third upper connecting member (Cb13), and the lower portion of the C-pillar (300) may be connected to the rear portion of the side sill (SS) by the third lower connecting member (Cb23).

[0047] As another example, the pillar section (PL) may further include a pillar positioned at the rear of the C-pillar (300) along the front-rear direction (X), such as a vehicle D-pillar (hereinafter referred to as D-pillar) (not shown).

[0048] FIG. 2 is a side view illustrating a vehicle side rail according to an embodiment of the present invention. FIG. 3 (a) is a cross-sectional view illustrating the front side rail constituting the side rail of FIG. 2 as viewed from the II' direction, and FIG. 4 (b) is a cross-sectional view illustrating the rear side rail constituting the side rail of FIG. 2 as viewed from the II-II' direction.

[0049] Referring to FIG. 2, the side rail (RS) may be a structure formed by combining a front side rail (SR1) and a rear side rail (SR2) that extend in different directions.

[0050] For example, the front side rail (SR1) may extend from the front to the rear of the vehicle along a direction inclined upward. The rear side rail (SR2) may extend from the rear end of the front side rail (SR1) toward the rear of the vehicle along the front-rear direction (X). In this case, the side rail (RS) may be provided in the form of a single structure in which the front end of the rear side rail (SR2) is connected to the rear end of the aforementioned front side rail (SR1). However, the present invention is not limited thereto, and the side rail (RS) may be provided in various forms based on the type and shape of the vehicle.

[0051] Referring to FIG. 3, the side rail (RS) may be formed such that the inner member (510) and the outer member (520) are joined together to form a closed cross-section. Such a side rail (RS) may be extended along its extension direction to have the same closed cross-section. Here, having the same closed cross-section may mean that the shape and area of ​​the closed cross-section formed inside, surrounded by the inner member (510) and the outer member (520), are identical.

[0052] Referring to FIG. 3(a), the front side rail (SR) may be a structure in which an inner member (hereinafter, first inner member) (510a) and an outer member (hereinafter, first outer member) (520a) are joined together to form a closed cross-section.

[0053] The first inner member (510a) may include a first body (511a) and a first flange (512a, 513a). In FIG. 3, the first body (511a) is shown to have an L-shaped cross-section, but is not limited thereto. The first body (511a) may be provided in various forms based on the type of vehicle, the location where the side rail (RS) is installed, etc.

[0054] Two first flanges (512a, 513a) are provided, and hereinafter, one of the two is referred to as the first-1 flange (512a) and the other of the two is referred to as the first-2 flange (513a). At this time, the first-1 flange (512a) and the first-2 flange (513a) may be placed at each end of the first body (511a). The first-2 flange (513a) may be placed at the bottom of the first body (511a).

[0055] More specifically, the first-1 flange (512a) may be positioned to protrude downward (-Z) from the lower end of the first body (511a). The first-2 flange (513a) may be positioned to protrude upward (+Z) from the upper end of the first body (511a). Accordingly, the first-1 flange (512a) and the first-2 flange (513a) may face each other with the first body (511a) in between.

[0056] The first outer member (520a) may include a second body (521a) and a second flange (522a, 523a). In FIG. 3, the second body (521a) is shown to have a hat-shaped cross-sectional form, but is not limited thereto. As previously mentioned, the second body (521a) may be provided in various forms based on the type of vehicle, the location where the side rail (RS) is installed, etc.

[0057] Two second flanges (522a, 523a) are provided, and hereinafter, one of the two is referred to as the second-1 flange (522a) and the other of the two is referred to as the second-2 flange (523a). At this time, the second-1 flange (522a) and the second-2 flange (523a) may be placed at each end of the second body (521a). The second-2 flange (523a) may be placed at the bottom of the first body (521a).

[0058] More specifically, the second-1 flange (522a) may be positioned to protrude downward (-Z) from the lower end of the second body (521a). The second-2 flange (523a) may be positioned to protrude upward (+Z) from the upper end of the second body (521a). Accordingly, the second-1 flange (522a) and the second-2 flange (523a) may face each other with the first body (521a) in between.

[0059] At least one of the first flange (512a, 513a) and the second flange (522a, 523a) as described above may include a bent portion.

[0060] The bent portion may be positioned at the upper end of the front side rail (SR1). More specifically, the bent portion (514a) may be positioned at the upper end of the first inner member (510a) or the first outer member (520a) and provided in a form bent in an inclined direction (hereinafter referred to as the bending direction) with respect to the extension direction (i.e., front-rear direction) (X) of the side rail (RS).

[0061] When a vehicle body frame unit (10) including this is installed in a vehicle, the direction facing inward in the vehicle may be referred to as the “-Y-axis direction” in the drawing. This is based on the case where the front side rail (SR1) is installed on the right side when viewed from the front of the vehicle. Although not shown in the drawing, if the front side rail (SR1) is installed on the left side of the vehicle, the inner direction may be the “+Y-axis direction.” For convenience of explanation, the following description will focus on the case where the inner direction is the “-Y-axis direction” and the outer direction is the “+Y-axis direction.”

[0062] In one embodiment (hereinafter, Example 1), the bent portion (514a) may be disposed on the first inner member (510a). In this case, the bent portion (514a) may be in the form in which the upper portion of the first-1 flange (512a) is bent in the inner direction (-Y) as described above. Accordingly, the first-2 flange (513a) may be in the shape of an 'L', comprising a 'straight portion' extending in a straight line for a predetermined length along the upward direction (+Z) from the upper portion of the first body (511a), and a bent portion (514a) bent in the inner direction (-Y) from this straight portion. In the case of Example 1, the first outer member (520b) is illustrated as not including a bent portion, but is not limited thereto.

[0063] When the first inner member (510a) and the first outer member (520a) are joined, the first-1 flange (512a) and the second-1 flange (522a) can be joined together in a state where they are in contact with each other. Also, the straight portions of the second-2 flange (523a) and the first-2 flange (513a) can be joined together in a state where they are in contact with each other. At this time, the first-2 flange (513a) and the second-2 flange (523a) can be joined using a first joining method. The first joining method may be, for example, a laser welding method.

[0064] The first flange (512a, 513a) and the second flange (522a, 523a) may have different lengths. In the case of Example 1, the first-1 flange (512a) may have a longer length than the second-1 flange (522a). The first-2 flange (513a) may have a longer length than the second-2 flange (523a). More specifically, the bent portion (514a) may be formed with a longer length than the second-2 flange (523a).

[0065] Due to this difference in length, when the first inner member (510a) and the first outer member (520a) are combined, a ‘first area (A15)’ in which the first flange (512a, 513a) and the second flange (522a, 523a) come into contact with each other and overlap, and a ‘second area (A25)’ in which only one of the first flange (512a, 514a) and the second flange (522a, 523a) is positioned can be formed.

[0066] More specifically, in the front side rail (SR1), a 'first area (A15)' in which the first-1 flange (512a) and the second-1 flange (522a) come into contact and overlap, and a 'first area (A15)' in which the straight portion of the first-2 flange (513a) and the second-2 flange (523a) come into contact and overlap may be formed. Additionally, in the front side rail (SR1), a 'second area (A25)' in which only the first-1 flange (512a) is positioned at the bottom of the front side rail (SR1), and a 'second area (A25)' in which only the bent portion (514a) is positioned at the top of the front side rail (SR1) may be formed.

[0067] In the above case, the first flange (512a, 513a) and the second flange (522a, 523a) can be joined in the first area (A15). Accordingly, a first weld (Wb15) can be formed in each of the first area (A15) formed at the top of the front side rail (SR1) and the first area (A15) formed at the bottom of the front side rail (SR1).

[0068] Meanwhile, the length of the second region (A25), the ‘second region length (L25)’, may be longer than the length of the first region (A15), the ‘first region length (L15)’. For example, the second region length (L25) may be more than twice the length of the first region (L15), but is not limited thereto.

[0069] As described above, a front side rail (SR1) can be manufactured by combining the first inner member (510a) and the first outer member (520a). Inside the front side rail (SR1), a closed empty space (E) can be formed, enclosed and partitioned by the first inner member (510a) and the first outer member (520a).

[0070] At this time, the front side rail (SR1) is manufactured by bending a plate material, such as a coil, using a roll forming method, which will be described later. In this way, the first inner member (510a) and the first outer member (520a) are joined together to form a closed cross-section, thereby enabling the manufacture of the front side rail (SR1).

[0071] Referring to FIG. 3(b), the rear side rail (SR2) may be a structure in which an inner member (hereinafter, second inner member) (510b) and an outer member (hereinafter, second outer member) (520b) are joined together to form a closed cross-section.

[0072] The second inner member (510b) may include a first body (511b) and a first flange (512b, 513b). In FIG. 3, the first body (511b) is shown to have an L-shaped cross-section, but is not limited thereto. As previously mentioned, the first body (511b) can be provided in various forms based on the type of vehicle, the location where the side rail (RS) is installed, etc.

[0073] Two first flanges (512b, 513b) are provided, and hereinafter, one of the two is referred to as the first-1 flange (512b) and the other of the two is referred to as the first-2 flange (513b). At this time, the first-1 flange (512b) and the first-2 flange (513b) may be placed at each end of the first body (511b). The first-2 flange (513b) may be placed at the bottom of the first body (511b).

[0074] More specifically, the first-1 flange (512b) may be positioned to protrude downward (-Z) from the lower end of the first body (511b). The first-2 flange (513b) may be positioned to protrude upward (+Z) from the upper end of the first body (511b). Accordingly, the first-1 flange (512b) and the first-2 flange (513b) may face each other with the first body (511b) in between.

[0075] The first outer member (520b) may include a second body (521b) and a second flange (522b, 523b). In FIG. 3, the second body (521b) is shown to have a hat-shaped cross-sectional form, but is not limited thereto. As previously mentioned, the second body (521b) may be provided in various forms based on the type of vehicle, the location where the side rail (RS) is installed, etc.

[0076] Two second flanges (522b, 523b) are provided, and hereinafter, one of the two is referred to as the second-1 flange (522b) and the other of the two is referred to as the second-2 flange (523b). At this time, the second-1 flange (522b) and the second-2 flange (523b) may be placed at each end of the second body (521b). The second-2 flange (523b) may be placed at the bottom of the first body (521b).

[0077] More specifically, the second-1 flange (522b) may be positioned to protrude downward (-Z) from the lower end of the second body (521b). The second-2 flange (523b) may be positioned to protrude upward (+Z) from the upper end of the second body (521b). Accordingly, the second-1 flange (522b) and the second-2 flange (523a) may face each other with the first body (521b) in between.

[0078] At least one of the first flange (512b, 513b) and the second flange (522b, 523b) as described above may include a bent portion.

[0079] The bend portion may be positioned at the upper end of the rear side rail (SR2). More specifically, the bend portion (514b) may be positioned at the upper end of the first inner member (510b) or the first outer member (520b) and provided in a form bent in a bending direction inclined with respect to the extension direction (i.e., front-rear direction) (X) of the side rail (RS). For example, the bending direction may be the inner direction (-Y) as described above.

[0080] In the case of Example 1, the bent portion (514b) may be disposed on the first inner member (510b). In this case, the bent portion (514b) may be in the form where the upper portion of the first-1 flange (512b) is bent in the aforementioned inner direction (-Y). Accordingly, the first-2 flange (513b) may be in the shape of an 'L', comprising a 'straight portion' extending in a straight line for a predetermined length along the upward direction (+Z) from the upper portion of the first body (511b), and a bent portion (514b) bent in the inner direction (-Y) from this straight portion. In the case of Example 1, the first outer member (520b) is illustrated as not including a bent portion, but is not limited thereto.

[0081] When the first inner member (510b) and the first outer member (520b) are joined, the first-1 flange (512b) and the second-1 flange (522b) can be joined together in a state where they are in contact with each other. Also, the straight portions of the second-2 flange (523b) and the first-2 flange (513b) can be joined together in a state where they are in contact with each other. At this time, the first-2 flange (513b) and the second-2 flange (522b) can be joined using the aforementioned 'first joining method'.

[0082] The first flange (512b, 513b) and the second flange (522b, 523b) may have different lengths. In the case of Example 1, the first-1 flange (512b) may have a longer length than the second-1 flange (522b). The first-2 flange (513b) may have a longer length than the second-2 flange (523b). More specifically, the bent portion (514b) may be formed with a longer length than the second-2 flange (523b).

[0083] Due to this difference in length, when the first inner member (510b) and the first outer member (520b) are combined, a ‘first area (A16)’ in which the first flange (512b, 513b) and the second flange (522b, 523b) come into contact with each other and overlap, and a ‘second area (A26)’ in which only one of the first flange (512b, 514b) and the second flange (522b, 523b) is positioned can be formed.

[0084] More specifically, in the rear side rail (SR2), a 'first area (A16)' in which the first-1 flange (512b) and the second-1 flange (522b) come into contact and overlap, and a 'first area (A16)' in which the straight portion of the first-2 flange (513b) and the second-2 flange (523b) come into contact and overlap may be formed. Additionally, in the front side rail (SR1), a 'second area (A26)' in which only the first-1 flange (512b) is positioned at the bottom of the rear side rail (SR2), and a 'second area (A26)' in which only the bent portion (514b) is positioned at the top of the rear side rail (SR2) may be formed.

[0085] In the above case, the first flange (512b, 513b) and the second flange (522b, 523b) can be joined in the first area (A16). Accordingly, a first weld (Wb16) can be formed in each of the first area (A16) formed at the top of the rear side rail (SR2) and the first area (A16) formed at the bottom of the rear side rail (SR2).

[0086] Meanwhile, the length of the second region (A26), the ‘second region length (L26)’, may be longer than the length of the first region (A16), the ‘first region length (L16)’. For example, the second region length (L26) may be more than twice the length of the first region (L16), but is not limited thereto.

[0087] As described above, a rear side rail (SR2) can be manufactured by combining the first inner member (510b) and the first outer member (520b). Inside the rear side rail (SR2), a closed empty space (E) can be formed, enclosed and partitioned by the first inner member (510b) and the first outer member (520b).

[0088] At this time, the rear side rail (SR2) is manufactured by bending a plate material, such as a coil, using a roll forming method, which will be described later. In this way, the rear side rail (SR2) can be manufactured by mutually combining the first inner member (510b) and the first outer member (520b) to form a closed cross-section.

[0089] In the above case, the front side rail (SR1) and the rear side rail (SR2) may be structures having the same closed cross-section. That is, the first inner member (510a) of the front side rail (SR1) and the second inner member (510b) of the rear side rail (SR2) may be formed in the same shape. Additionally, the first outer member (520a) of the front side rail (SR1) and the second outer member (520b) of the rear side rail (SR2) may be provided to have the same shape. Accordingly, the closed empty space (E) formed inside the front side rail (SR1) and the closed empty space (E) formed inside the rear side rail (SR2) may have the same shape. In this way, the front side rail (SR1) and the rear side rail (SR2) may have the same closed cross-section and may be extended along their respective extension directions.

[0090] As explained above, since the front side rail (SR1) and the rear side rail (SR2), which have the same closed cross-section, are connected to form the side rail (RS), the following description will focus on the 'side rail (RS)' without distinguishing between the front side rail (SR1) and the rear side rail (SR2).

[0091] As described above, the side rail (SR) may include an inner member (510) including a first flange (512, 513) and an outer member (520) including a second flange (522, 523).

[0092] The inner member (510) may include two first flanges (512, 513). The inner member (510) may have a first-1 flange (512) provided at its lower end and a first-2 flange (513) provided at its upper end. Additionally, the outer member (520) may include two second flanges (522, 523). The outer member (520) may have a second-1 flange (522) provided at its lower end and a second-2 flange (523) provided at its upper end.

[0093] Additionally, the side rail (RS) may include a 'first area (A10)' in which the first flange (512, 513) and the second flange (522, 523) are placed together and joined to each other, and a 'second area (A20)' in which only one of the first flange (512, 513) or the second flange (522, 523) is placed. The first flange (512, 513) and the second flange (522, 523) are joined in the first area (A10) by a first joining method, and thereby a first weld (Wb1) may be formed in the first area (A10).

[0094] At this time, the 'second region length (L2)', which is the length of the second region (A20), may be longer than the 'first region length (L1)', which is the length of the first region (A10). The second region length (L2) may be at least twice the length of the first region (L1). For example, the first region length (L1) may be 2 to 7 mm, and the second region length (L2) may be 10 to 15 mm. Preferably, the first region length (L1) may be at least 5 mm, and the second region length (L2) may be at least 13 mm, but is not limited thereto.

[0095] The bent portion may be placed on at least one of the first flange (512, 513) and the second flange (522, 523). At this time, the position and / or number of the bent portion may be provided in various forms, and this will be explained through the embodiments below.

[0096] FIG. 4 is a cross-sectional view showing one additional part attached to a vehicle side rail as viewed from the II' direction or the II-II' direction of FIG. 1.

[0097] Referring to FIG. 4, additional parts may be attached to the side rail (RS). The additional parts may be other components of the vehicle assembled to the body frame unit (10), for example, a side outer (SO).

[0098] The side outer (SO) can be coupled to a second area (A20) of the side rail (RS). More specifically, one end of the side outer (SO) can be coupled to either of the two second areas (A20) formed in the side rail (RS). And, the other end of the side outer (SO) can be coupled to the other of the two second areas (A20) formed in the side rail (RS). By being coupled in this way, the outer side of the side rail (RS) can be covered by the side outer (SO).

[0099] Accordingly, when the side outer (SO) is coupled to the side rail (RS), the side rail (RS) may not be visible to the naked eye from the outside of the vehicle. Here, "outer" refers to the direction toward the outside of the vehicle, and based on the case where the side rail (RS) is installed on the right side of the vehicle when viewed from the front, it may be the aforementioned "+Y-axis direction." However, as previously mentioned, if the side rail (RS) is installed on the left side of the vehicle, the outer direction may be the "-Y-axis direction," similar to what was previously stated.

[0100] The side outer (SO) can be joined to the second region (A20) using a second joining method. The second joining method may be different from the first joining method. For example, the first joining method may be a laser welding method, and the second joining method may be a spot welding method.

[0101] In the above case, the first region (A10) may have a narrower area than the second region (A20) due to the relatively short length (L1) of the first region. By applying concentrated heat to this first region (A10) through the first joining method, the inner member (510) and the outer member (520) can be joined. Accordingly, as previously described, a first weld (Wb1) is formed in the first region (A10).

[0102] On the other hand, the second region (A20) may have a larger area than the first region (A10) due to the relatively long second region length (L2). A side outer (SO) can be joined to this second region (A20) by applying heat through a second joining method, a 'spot welding method'. At this time, one end of the side outer (SO) can be joined to the second region (A20) of the first-1 flange (512) by a spot welding method to form a second weld (Wb2). Then, the other end of the side outer (SO) can be joined to the second region (A20) of the first-2 flange (513) by a spot welding method to form a second weld (Wb2).

[0103] In this way, the first inner / outer members (510, 520) constituting the side rail (RS) are joined together in the first area (A10), and separately, additional parts such as the side outer (SO) can be joined to the second area (A20) where only one of the first and second flanges (511, 512, 521, 522) is placed.

[0104] Accordingly, at the part where the side outer (SO) is joined, the second weld (Wb2) can be formed as a double weld by welding only one flange and the side outer (SO) in an overlapping state. In this way, even when additional parts are joined to the side rail (RS), a double weld is formed at the part where the additional parts are joined, and as a result, while securing high strength of the joined part, it is possible to prevent an increase in the weight of the vehicle body frame unit (10) due to excessive overlapping of welds.

[0105] FIG. 5 is a cross-sectional view showing two additional parts combined on a vehicle side rail as viewed from the II' direction or the II-II' direction of FIG. 1.

[0106] Referring to FIG. 5, two additional parts may be attached to the side rail (RS). The additional parts are other components of the vehicle assembled to the body frame unit (10), such as a side outer (SO) and a roof panel (RP). The roof panel (RP) may be a part for connecting the side rail (RS) and the roof. At this time, after one of the additional parts is attached to the side rail (RS), another additional part may be additionally attached to the side rail (RS) and the additional part thus attached.

[0107] For example, a side outer (SO) may be first attached to a side rail (RS), and then a roof panel (RP) may be additionally attached to the part where they are attached. However, the present invention is not limited thereto, and the order of attachment of additional parts may be changed.

[0108] First, the side outer (SO) can be connected to the second area (A20) of the side rail (RS). At this time, one end of the side outer (SO) can be connected to the second area (A20) formed at the upper end of the side rail (RS). Then, the other end of the side outer (SO) can be connected to the second area (A20) formed at the lower end of the side rail (RS). At this time, the side outer (SO) is connected to the second area (A20) of the side rail (RS) through a 'second connection method [e.g., spot welding method]' as previously described.

[0109] Subsequently, a roof panel (RP) may be additionally attached to the portion (hereinafter referred to as the joint portion) where the side outer (SO) and the side rail (RS) are joined. That is, the roof panel (RP) may be attached to the second area (A20) where the aforementioned joint portion is formed. The roof panel (RP), like the side outer (SO), may be attached to the joint portion by a second joining method [e.g., spot welding method].

[0110] Accordingly, at the part where the side outer (SO) and the roof panel (RP) are joined, the second weld (Wb2) can be formed as a three-layer weld by welding one of the flanges, the side outer (SO), and the roof panel (RP) in an overlapping state. That is, even when two additional parts (SO, RP) are assembled to the side rail (RS), only a three-layer weld can be formed at the part where the additional parts are joined. As a result, a four-layer weld is not formed on the side rail (RS), thereby ensuring high strength of the joined part while preventing the weight of the vehicle body frame unit (10) from increasing excessively.

[0111] FIG. 6(a) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the I-I' direction of FIG. 1 or FIG. 2, and FIG. 6(b) is a cross-sectional view showing a side rail according to yet another embodiment of the present invention as viewed from the II' direction of FIG. 1 or FIG. 2.

[0112] Referring to FIG. 6(a), a side rail (RSa) according to another embodiment of the present invention (hereinafter, Embodiment 2) may be a structure in which an inner member (510) and an outer member (520) are mutually coupled to form a closed cross-section. The inner member (510) may be in the form in which a first flange (512, 513) is disposed at each of both ends of a first body (511), and the outer member (520) may be in the form in which a second flange (522, 523) is disposed at each of both ends of a second body (521). Since most of the features of such an inner member (510) and an outer member (520) are the same or similar as those described above, the following description will focus on the differences.

[0113] In the case of Example 2, one bent portion (514) may be provided and placed in the inner member (510). At this time, the bent portion (514) may have a shape that is bent toward the inner direction (-Y) from the upper part of the first-second flange (513). Accordingly, the first-second flange (513) may have a shape in which a straight portion (513L) extending in the upward direction (+Z) and a bent portion (514) connected to the upper part of the straight portion (513L) and extending in the inner direction (-Y) are connected. For example, the first-second flange (513) may have a cross-sectional shape in the shape of an 'L'.

[0114] In contrast, the second-2 flange (523) may be extended in a straight line along the upward direction (+Z). In this case, the second-2 flange (523) may have a shorter length than the first-2 flange (513). For example, the second-2 flange (523) may have a shorter length than the straight section (513L) of the first-2 flange (513). As another example, the second-2 flange (523) may have the same length as the straight section (513L).

[0115] Both the 1-1 flange (512) and the 2-1 flange (522) can be extended in a straight line along the downward direction (-Z). In this case, the 1-1 flange (512) may have a longer length than the 2-1 flange (522).

[0116] In the above case, the first region (A10) can be formed in the ‘part where the straight portion (513L) of the second-2 flange (523) and the first-2 flange (513) are placed together in contact’ and the ‘part where the first-1 flange (512) and the second-1 flange (522) are placed together in contact’, respectively.

[0117] In the second area (A20), only the first flange (512, 513) may be placed. More specifically, in the second area (A20) formed on the upper part of the side rail (RS), only the bent portion (514) of the first-second flange (513) may be placed. And, in the second area (A20) formed on the lower part of the side rail (RS), only the first-second flange (513) may be placed.

[0118] At this time, the straight section (513L) and the second-second flange (523) can be joined by the first joining method, and a first weld (Wb1) can be formed between them. Likewise, the first-second flange (513) and the second-second flange (523) can be joined by the first joining method, and a first weld (Wb1) can be formed between them. In addition, the additional parts (SO, RP) described above can be joined to the second area (A20) to form a second weld (Wb2).

[0119] To this end, as previously described, the second region length (L2) is formed to be longer than the first region length (L1). At this time, since the second region (A20) located at the top corresponds to the bending portion (514), the length of the bending portion (514) can correspond to the second region length (L2). Accordingly, the bending portion (514) can have a length longer than the first region length (L1).

[0120] Referring to FIG. 6(b), a side rail (RSb) according to another embodiment of the present invention (hereinafter, embodiment 3) may be a structure in which an inner member (510) and an outer member (520) are mutually joined to form a closed cross-section.

[0121] The side rail (RSb) is provided with one bent portion (514), similar to Example 2, and can be placed on the first-second flange (513) of the inner member (510).

[0122] That is, the first-2 flange (513) may be in the shape of an 'L', with a straight section (513L) extending in the upward direction (+Z) and a bent section (514) connected to the upper part of the straight section (513L) and extended by being bent in the inward direction (-Y). On the other hand, the second-2 flange (523) may extend in a straight line along the upward direction (+Z). The second-2 flange (523) may have a shorter length than the straight section (513L) or the same length as the straight section (513L).

[0123] Accordingly, a first region (A10) may be formed in each of the 'part where the straight portion (513L) of the second-2 flange (523) and the first-2 flange (513) are placed together in contact' and the 'part where the first-1 flange (512) and the second-1 flange (522) are placed together in contact'. As previously described, a first weld (Wb1) is formed in such a first region (A10).

[0124] Both the first-1 flange (512) and the second-1 flange (522) can be extended in a straight line along the downward direction (-Z). Unlike in Example 2, the side rail (RSb) of Example 3 may have the first-1 flange (512) have a shorter length than the second-1 flange (522). Accordingly, only the bent portion (514) of the first-2 flange (513) may be placed in the second area (A20) above the side rail (RSb). On the other hand, only the second-1 flange (522) may be placed in the second area (A20) below the side rail (RSb).

[0125] Other features of the side rail (RSb) are identical or similar to those of Example 2 described above, so a redundant description will be omitted.

[0126] FIG. 7(a) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the direction II' of FIG. 1 or FIG. 2, and FIG. 7(b) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the direction II' of FIG. 1 or FIG. 2.

[0127] Referring to FIG. 7(a), a side rail (RSc) according to another embodiment of the present invention (hereinafter, embodiment 4) is a structure in which an inner member (510) and an outer member (520) are mutually coupled to form a closed cross-section, and a bending portion (514) is provided and can be placed on the outer member (520).

[0128] More specifically, the bent portion (524) of Example 4 may be bent inward (-Y) at the upper portion of the second-2 flange (523). Accordingly, the second-2 flange (523) may be in a form in which a straight portion (523L) extending inward (+Z) and a bent portion (524) connected to the upper portion of the straight portion (523L) and extending inward (-Y) are connected. For example, the first-2 flange (513) may have an L-shaped cross-sectional shape.

[0129] Alternatively, the first-2 flange (513) may extend straight from the first body (511) along the upward direction (+Z). In this case, the first-2 flange (513) may have a shorter length than the second-2 flange (523). For example, the first-2 flange (513) may have a shorter length than the straight section (523L) of the second-2 flange (523). As another example, the first-2 flange (513) may have the same length as the straight section (523L).

[0130] Both the 1-1 flange (512) and the 2-1 flange (522) can be extended in a straight line along the downward direction (-Z). In this case, the 1-1 flange (512) may have a longer length than the 2-1 flange (522).

[0131] In the above case, the first region (A10) can be formed in the ‘part where the straight portion (523L) of the first-2 flange (513) and the second-2 flange (523) are placed together in contact’ and the ‘part where the first-1 flange (512) and the second-1 flange (522) are placed together in contact’, respectively.

[0132] In the second area (A20), only the second flange (522, 523) may be placed. More specifically, in the second area (A20) formed on the upper part of the side rail (RS), only the bent portion (524) of the second-2 flange (523) may be placed. And, in the second area (A20) formed on the lower part of the side rail (RS), only the second-1 flange (522) may be placed.

[0133] At this time, the straight section (523L) and the first-second flange (513) may be joined by the first joining method, and a first weld (Wb1) may be formed between them. Likewise, the first-first flange (512) and the second-first flange (522) may be joined by the first joining method, and a first weld (Wb1) may be formed between them. Additionally, the above-described additional parts (SO, RP) may be joined to the second region (A20) to form a second weld (Wb2).

[0134] To this end, as previously described, the second region length (L2) is formed to be longer than the first region length (L1). At this time, since the second region (A20) located at the top corresponds to the bending portion (524), the length of the bending portion (524) can correspond to the second region length (L2). Accordingly, the bending portion (524) can have a length longer than the first region length (L1).

[0135] Referring to FIG. 7(b), a side rail (RSd) according to another embodiment of the present invention (hereinafter, embodiment 5) may be a structure in which an inner member (510) and an outer member (520) are mutually joined to form a closed cross-section.

[0136] The side rail (RSd) may be provided with one bent portion (524), as in Example 4, and may be placed on the first-second flange (513) of the inner member (510).

[0137] That is, the second-2 flange (523) may be in the shape of an 'L', with a straight section (523L) extending in the upward direction (+Z) and a bent section (524) connected to the upper part of the straight section (523L) and extended by being bent in the inward direction (-Y). On the other hand, the first-2 flange (513) may be extended in a straight line along the upward direction (+Z). The first-2 flange (513) may have a shorter length than the straight section (523L) or the same length as the straight section (523L).

[0138] Accordingly, a first region (A10) may be formed in each of the 'part where the straight portions (523L) of the first-2 flange (513) and the second-2 flange (523) are placed together in contact' and the 'part where the first-1 flange (512) and the second-1 flange (522) are placed together in contact'. As previously described, a first weld (Wb1) is formed in such a first region (A10).

[0139] Both the first-1 flange (512) and the second-1 flange (522) can be extended in a straight line along the downward direction (-Z). Unlike in Example 4, the side rail (RSd) of Example 3 may have the first-1 flange (512) formed to be longer than the second-1 flange (522). Accordingly, only the bent portion (524) of the second-2 flange (523) may be placed in the second area (A20) above the side rail (RSd). On the other hand, only the first-1 flange (512) may be placed in the second area (A20) below the side rail (RSd).

[0140] Other features of the side rail (RSd) are identical or similar to those of Example 4 described above, so a redundant description will be omitted.

[0141] FIG. 8(a) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the direction II' of FIG. 1 or FIG. 2, and FIG. 8(b) is a cross-sectional view showing a side rail according to another embodiment of the present invention as viewed from the direction II' of FIG. 1 or FIG. 2.

[0142] Referring to FIG. 8(a), a side rail (RSe) according to another embodiment of the present invention (hereinafter, Embodiment 6) may be a structure in which an inner member (510) and an outer member (520) are mutually joined to form a closed cross-section. In the case of Embodiment 6, two bending portions are provided, and one may be placed on each of the inner member (510) and the outer member (520). Hereinafter, the bending portion of the inner member (510) will be referred to as the first bending portion (514), and the bending portion of the outer member (520) will be referred to as the second bending portion (524).

[0143] More specifically, the first bend portion (514) may have a shape that is bent inward (-Y) at the upper end of the first-second flange (513). Accordingly, the first-second flange (513) may be in a shape in which a first straight portion (513L) extending inward (+Z) and a first bend portion (514) connected to the upper end of the first straight portion (513L) and extending inward (-Y) are connected. For example, the first-second flange (513) may have an L-shaped cross-sectional shape.

[0144] The second bend portion (524) may be bent inward (-Y) at the upper end of the second-2 flange (523). Accordingly, the second-2 flange (523) may be formed by connecting a second straight portion (523L) extending inward (+Z) and a second bend portion (523L) connected to the upper end of the second straight portion (523L) and extending inward (-Y). For example, the first-2 flange (513) may have an L-shaped cross-sectional shape.

[0145] At this time, the first-2 flange (513) may have a shorter length than the second-2 flange (523). For example, the first straight section (513L) and the second straight section (523L) may have the same length, but the first bent section (514) may have a shorter length than the second bent section (524).

[0146] Both the first-1 flange (512) and the second-1 flange (522) can be extended in a straight line along the downward direction (-Z). The first-1 flange (512) and the second-1 flange (522) can be formed with different lengths. For example, the first-1 flange (512) may have a longer length than the second-1 flange (522). The present invention is not limited thereto, and the first-1 flange (512) may have a shorter length than the second-1 flange (522). However, for convenience of explanation, the first-1 flange (512) will be described primarily in an embodiment where it is longer than the second-1 flange (522).

[0147] In the above case, the first region (A10) may be formed in the 'part where the first-1 flange (512) and the second-1 flange (522) are placed together in contact' and the 'part where the first-2 flange (513) and the second-2 flange (523) are placed together in contact', respectively. A first weld (Wb1) may be formed in such a first region (A10).

[0148] In the second area (A20) of the upper side rail (RSe), only the second bend (524) may be placed. On the other hand, in the second area (A20) of the lower side rail (RSe), only the first flange (512) may be placed. In such a second area (A20), one or two additional parts (SO, RP) as described above may be combined to form a second weld (Wb2).

[0149] Referring to FIG. 8(b), a side rail (RSf) according to another embodiment of the present invention (hereinafter, Embodiment 7) may be a structure in which an inner member (510) and an outer member (520) are mutually joined to form a closed cross-section.

[0150] The side rail (RSf) is provided with two bends (514), similar to Example 6, and can be placed on the second-2 flange (523) of the inner member (510) and the second-2 flange (523) of the outer member (520), respectively.

[0151] That is, the first-2 flange (513) may have an L-shape formed by connecting a first straight section (513L) extending in the upward direction (+Z) and a first bent section (514) extending by being bent in the inward direction (-Y). Additionally, the second-2 flange (523) may have an L-shape formed by connecting a twelfth straight section (523L) extending in the upward direction (+Z) and a second bent section (524) extending by being bent in the inward direction (-Y).

[0152] In this case, in the case of Example 7, the first-2 flange (513) may have a longer length than the second-2 flange (523). For example, the first straight section (513L) and the second straight section (523L) may have the same length, but the first bent section (514) may have a longer length than the second bent section (524).

[0153] Both the first-1 flange (512) and the second-1 flange (522) can be extended in a straight line along the downward direction (-Z). At this time, the first-1 flange (512) may have a longer length than the second-1 flange (522), but is not limited thereto. As another example, the first-1 flange (512) may have a shorter length than the second-1 flange (522), but for convenience of explanation, the first-1 flange (512) is described primarily in an embodiment where it is longer than the second-1 flange (522).

[0154] In the above case, the first region (A10) may be formed in the 'part where the first-1 flange (512) and the second-1 flange (522) are placed together in contact' and the 'part where the first-2 flange (513) and the second-2 flange (523) are placed together in contact', respectively. In addition, only the first bend (514) may be placed in the second region (A20) above the side rail (RSf). On the other hand, only the first-1 flange (512) may be placed in the second region (A20) below the side rail (RSf).

[0155] As previously mentioned, a first weld (Wb1) is formed in such a first region (A10), and a second weld (Wb2) can be formed in the second region (A20) by combining one or two additional parts (SO, RP).

[0156] Meanwhile, the side rail (RS) according to the embodiments described above can be manufactured using a roll forming device (not shown).

[0157] A method for manufacturing a loop side rail (RS) according to one embodiment of the present invention may be as follows.

[0158] The roll forming device may include a first roll forming unit (not shown) and a second roll forming unit (not shown). The first roll forming unit and the second roll forming unit may be arranged side by side in a horizontal direction (e.g., left-right direction) and extend along the same direction.

[0159] Two plates can be supplied simultaneously to the roll forming device. One of the two plates, the first plate, can be supplied to the first roll forming unit, and the other of the two plates, the second plate, can be supplied to the second roll forming unit. After being supplied to the roll forming device, the first plate and the second plate can be transported in the same direction. The transport direction of the first and second plates may be the same direction as the extension direction of the first roll forming unit and the second roll forming unit. Meanwhile, the aforementioned horizontal direction may refer to the width direction of the first and second plates supplied to the device, and may mean a direction perpendicular to the transport direction.

[0160] For example, the first roll forming unit and the second roll forming unit may be provided as separate units. In this case, the first roll forming unit and the second roll forming unit may be arranged to face each other in the left-right direction and extended parallel to each other along the aforementioned extension direction to form a roll forming device. As another example, the first roll forming unit and the second roll forming unit may be provided as a single device. In this case, the first roll forming unit may form a part of the roll forming device, and the second roll forming unit may form a different part of the roll forming device.

[0161] The first roll forming unit may include a first front forming section and a first forming section.

[0162] The first front forming section is a part that bends and forms the first plate material, and may include a plurality of first front roller sets arranged in a row along the above-mentioned conveying direction.

[0163] The first front roller set may include a first pressing part for applying pressure to at least a portion of the first plate material to form a bend. The first pressing part may be formed in a protruding shape and / or a groove shape. In this case, the shape, location, and number of the first pressing part may be changed based on the target shape of the first plate material [or the target shape of the loop side rail (RS)] to be bent by the first front forming part.

[0164] When supplied to the first front roller set, the first plate passes through the first pressing sections of a plurality of first front forming sections along the conveying direction and can be bent and formed by gradually applying pressure. By doing so, first flanges (512, 512a, 512b, 513, 513a, 513b) can be formed at both ends of the first plate. That is, by the first front forming section, an inner member (510, 510a, 510b) having an open cross-section and including first flanges (512, 512a, 512b, 513, 513a, 513b) at both ends can be manufactured. The inner member (510, 510a, 510b) can be manufactured in a hat shape, but is not limited thereto.

[0165] In the above case, the first pressure part and the second pressure part may be provided in the same or different forms. For example, if the loop side rail (RS) is manufactured in a symmetrical shape, the first pressure part and the second pressure part may be provided in the same form. As another example, if the loop side rail (RS) is manufactured in an asymmetrical shape, the first pressure part and the second pressure part may be provided in different forms.

[0166] The first forming section is a part that processes the first plate material formed by bending so that it rotates, and can be positioned downstream of the first front forming section with respect to the conveying direction.

[0167] The first forming section may include a plurality of first roller sets arranged in a row along the aforementioned conveying direction. The first roller sets may be positioned downstream of the first front roller set so as to be continuous with the first front roller set.

[0168] Accordingly, a plurality of first front roller sets and a plurality of first roller sets can be continuously arranged in a line along the conveying direction. The first plate material that has passed through the first front forming section can be rotated in the first forming section, and this will be described later.

[0169] Similarly, the second roll forming unit may include a second front forming section and a second forming section.

[0170] The second front forming section is a part that bends and forms the second plate material, and may include a plurality of second front roller sets arranged in a row along the aforementioned conveying direction.

[0171] The second front roller set may include a second pressing part for bending and forming at least a portion of the second plate by pressing it. The second pressing part may be formed in a protruding shape and / or a groove shape. In this case, the shape, location, and number of the second pressing part may be changed based on the target shape of the second plate [or the target shape of the loop side rail (RS)] that is bent by the first front forming part.

[0172] When supplied to the second front roller set, the second plate passes through the second pressing sections of a plurality of first front forming sections along the conveying direction and can be bent and formed by gradually applying pressure. By doing so, second flanges (522, 522a, 522b, 523, 523a, 523b) can be formed at both ends of the second plate. That is, by the second front forming section, an outer member (520, 520a, 520b) having an open cross-section and including second flanges (522, 522a, 522b, 523, 523a, 523b) at both ends can be manufactured. The outer member (520, 520a, 520b) can be manufactured in a hat shape, but is not limited thereto.

[0173] The second forming section is a part that processes the second plate material, which has been bent, to rotate, and can be positioned downstream of the second front forming section with respect to the conveying direction.

[0174] The second forming section may include a plurality of second roller sets arranged in a row along the aforementioned transfer direction. The second roller sets may be positioned downstream of the first front roller set so as to be continuous with the second front roller set.

[0175] Accordingly, a plurality of second front roller sets and a plurality of second roller sets can be continuously arranged in a line along the conveying direction. The first plate material that has passed through the first front forming section can be rotated in the first forming section, and this will be described later.

[0176] In the above case, the first front forming section and the second front forming section are arranged side by side in the aforementioned left-right direction, and the first forming section and the second forming section may be arranged side by side in the aforementioned left-right direction. In this state of being arranged side by side, the first plate and the second plate can be supplied simultaneously to the first front forming section and the second front forming section.

[0177] After passing through the first and second front forming sections as described above, the first plate can be supplied to the first forming section, and the second plate can be supplied to the second forming section.

[0178] The first plate can pass through a plurality of first roller sets provided in the first forming section along the conveying direction. During this process, the first plate can gradually rotate toward the second plate.

[0179] When pressurized between the first roller sets, the first plate may be sandwiched between the first roller sets so as to be inclined at a predetermined angle (hereinafter referred to as the first angle) with respect to the width direction described above. At this time, as the first forming section moves from upstream to downstream, the plurality of first roller sets may be configured such that the first angle gradually increases. Accordingly, the first plate may gradually rotate to approach the second plate while passing through the plurality of first roller sets along the conveying direction.

[0180] Similarly, the second plate can pass through a plurality of second roller sets provided in the second forming section along the conveying direction. During this process, the second plate can gradually rotate toward the first plate.

[0181] When pressurized between the second roller sets, the second plate may be sandwiched between the second roller sets so as to be inclined at a predetermined angle (hereinafter referred to as the second angle) with respect to the width direction described above. At this time, as the second forming section moves from upstream to downstream, the plurality of second roller sets may be configured such that the second angle gradually increases. Accordingly, the second plate may gradually rotate to approach the first plate while passing through the plurality of second roller sets along the conveying direction.

[0182] In the above case, the shape of the first roller set and / or the second roller set, the size of the first angle and / or the second angle, or the degree to which the first angle and / or the second angle increases along the conveying direction may be changed based on the target shape of the loop side rail (RS) being manufactured.

[0183] Meanwhile, as the bending forming step by the aforementioned first and second front forming parts and the rotational processing step by the first and second forming parts are performed, at least one upper part of the first-2 flange (513) and the second-2 flange (523) may be bent to form a bent portion (514).

[0184] When the rotational processing of the first plate and the second plate is completed in the manner described above, the first plate and the second plate may be in a 'contact state' in which at least a portion is in contact. The contact portions of the plates may be the first flange (512, 512a, 512b, 513, 513a, 513b) and the second flange (522, 522a, 522b, 523, 523a, 523b). That is, the contact state may mean a state in which the first flange (512, 512a, 512b, 513, 513a, 513b) of the inner member (510, 510a, 510b) and the second flange (522, 522a, 522b, 523, 523a, 523b) of the outer member (520, 520a, 520b) are in one-to-one contact.

[0185] Meanwhile, the aforementioned bending forming and rotational processing may be performed at least partially simultaneously. That is, the first plate and the second plate may gradually rotate toward each other while the bending forming is in progress. However, the present invention is not limited thereto, and the bending forming and rotational processing may be performed at different times. That is, rotational processing may begin after the bending processing of the first plate and the second plate is completed.

[0186] The plates in contact can be continuously transported along the transport direction. At this time, the plates in contact can be transported while being pressed by the first roller set and the second roller set.

[0187] While being transported under pressure in this manner, the contact portions of the plates can be welded and joined by a joining unit. More specifically, the joining unit continuously irradiates a laser beam at a specific point along the transport path of the plates, and the first flange (512, 512a, 512b, 513, 513a, 513b) and the second flange (522, 522a, 522b, 523, 523a, 523b) that are in contact with each other pass through the aforementioned specific point and can be welded by the laser.

[0188] In this manner, the first-1 flange (112) located on both sides of the contact plates is welded to the second-1 flange (122), and the first-2 flange (113) is welded to the second-2 flange (123), thereby forming a first weld (Wb1). At this time, the first weld (Wb1) is formed in the first region (A10) as previously described.

[0189] When welding is completed in the manner described above, the first plate and the second plate are joined together to form a single structure having a closed cross-section and a long length. Even after welding is completed, the structure can be pressed by roller sets positioned downstream of the roll forming device. In this way, by pressing the welded flanges (112, 113, 122, 123), thermal deformation such as warping of the plate caused by laser welding can be prevented.

[0190] Meanwhile, when supplying the plates, the distance between the first plate and the second plate in the width direction described above can be adjusted. For example, the first plate and the second plate may be supplied in a state where they are almost in contact in the width direction, or, as another example, the first plate and the second plate may be supplied in a state where they are separated by a predetermined distance in the width direction.

[0191] In this way, when supplied with the distance between the plates adjusted, the steps of bending, rotational processing, and welding can be performed as the first plate and the second plate move along the conveying direction while maintaining the adjusted distance. At this time, the position and shape of the plates being bent can be adjusted based on whether the first plate and the second plate are separated and the change in the distance between them. Additionally, the contact area between the first flange (512, 512a, 512b, 513, 513a, 513b) and the second flange (522, 522a, 522b, 523, 523a, 523b) can be varied so that the position and area of ​​the first region (A10) and the second region (A20) can be adjusted. Accordingly, various types of loop side rails (RS) can be manufactured using a single roll forming device without changing the device.

[0192] Subsequently, by cutting the above-mentioned structure to a predetermined length, a unit structure with an adjustable length [e.g., a front side rail (SR1) and a rear side rail (SR2)] or a loop side rail (RS) can be manufactured. Additionally, various types of loop side rails (RS) can be manufactured by preparing a plurality of the unit structures cut to a predetermined length, arranging them to extend in different directions, and then reassembling them.

[0193] A method for manufacturing a loop side rail (RS) according to another embodiment of the present invention may be as follows.

[0194] The roll forming device may include a first roll forming unit (not shown) and a second roll forming unit (not shown) arranged to face each other in the vertical or horizontal direction and extending parallel along a first conveying direction. Additionally, the roll forming device may further include a shearing unit (not shown) and a joining unit (not shown).

[0195] The first roll forming unit may be extended to a length longer than that of the second roll forming unit based on the first conveying direction. At this time, the roll forming device may include a roll forming section in which the front portion of the first roll forming unit and the second roll forming unit are arranged together to form an inner member (510, 510a, 510b) and an outer member (520, 520a, 520b) by bending. The roll forming device may further include a transition section located at the rear of the roll forming section, in which the conveying direction of any one of the inner member (510, 510a, 510b) and the outer member (520, 520a, 520b) after bending is completed is switched to a second conveying direction. Additionally, the roll forming device may further include a coupling section located behind the aforementioned transition section, in which the inner member (510, 510a, 510b) and the outer member (520, 520a, 520b) are transported together in a first transport direction and coupled to each other. Such roll forming section, transition section, and coupling section may be provided to be continuous along the first transport direction.

[0196] For example, the first roll forming unit may receive a first plate in the form of a coil and perform bending forming processing to manufacture an inner member (510, 510a, 510b). At this time, the first roll forming unit may include a plurality of upper rolls and lower rolls arranged in a row along a first conveying direction. The first plate may be bent and formed by passing between the plurality of upper rolls and lower rolls along the first conveying direction and being gradually pressed. By doing so, a first flange (512, 512a, 512b, 513, 513a, 513b) is formed on each side of the first plate, thereby manufacturing an inner member (510, 510a, 510b) in a form that is bent multiple times.

[0197] Additionally, the second roll forming unit can receive a second plate in the form of a coil and perform bending forming processing to manufacture an outer member (520, 520a, 520b). At this time, the second roll forming unit may include a plurality of upper rolls and lower rolls arranged in a row along a first conveying direction. The second plate can be bent and formed by passing between the plurality of upper rolls and lower rolls along the first conveying direction and being gradually pressed. By doing so, a second flange (522, 522a, 522b, 523, 523a, 523b) is formed on each side of the second plate, thereby manufacturing an outer member (520, 520a, 520b) in a form that is bent multiple times.

[0198] In the above case, a portion of the second plate may be sheared by a shearing unit before entering the roll forming section. The sheared portion (hereinafter referred to as the narrow portion) may have a narrower width compared to other parts of the second plate that are not sheared. Additionally, when the narrow portion of the second plate passes through the second roll forming unit, it may not come into contact with the upper roll and the lower roll due to its narrow width. As a result, even after the bending process of the second plate is completed, the narrow portion of the second plate may have a flat plate shape without any bent portion. Due to having such a shape, the narrow portion may have lower rigidity than other parts of the outer member (520, 520a, 520b) (e.g., the part where the second flange is formed).

[0199] Additionally, a plurality of narrow sections may be spaced apart and formed in the outer members (520, 520a, 520b). When the bending forming is completed, the outer members (520, 520a, 520b) may have a long, extended shape in which second flanges (522, 522a, 522b, 523, 523a, 523b) are arranged between the aforementioned plurality of narrow sections.

[0200] The bending forming process of the roll forming method described above can be performed in the aforementioned roll forming section. In addition, the bending forming process of the first roll forming unit and the bending forming process of the second roll forming unit can be performed simultaneously.

[0201] After passing through the roll forming section, the inner members (510, 510a, 510b) can continue to move along the first conveying direction, pass through the transition section, and enter the joining section.

[0202] On the other hand, when the outer member (520, 520a, 520b) enters the transition section, the transfer direction may be switched to a second transfer direction. As the second roll forming unit is spaced apart from the first roll forming unit in the up-down or left-right direction, the second transfer direction may be a direction inclined upward, downward, left, or right relative to the first transfer direction.

[0203] After the transfer direction is switched, the outer members (520, 520a, 520b) can move along the second transfer direction, pass through the transition section, and be transferred to the rear end of the first roll forming unit placed within the coupling section. At this time, prior to entering the coupling section, the transfer direction of the outer members (520, 520a, 520b) can be switched back to the first transfer direction.

[0204] In this way, when the transfer direction is switched and re-switched, the outer members (520, 520a, 520b) move while partially bending because the second transfer direction is inclined with respect to the first transfer direction. At this time, the outer members (520, 520a, 520b) may have a narrow section with relatively low rigidity and an adjacent section that bends, and the transfer direction may be switched or re-switched. By including the narrow section in this manner, damage such as buckling can be prevented from occurring in the outer members (520, 520a, 520b) when the transfer direction is switched.

[0205] Then, the inner members (510, 510a, 510b) and the outer members (520, 520a, 520b) can be transported along the first transport direction in a state where they meet and overlap at the joint section. At this time, the inner members (510, 510a, 510b) and the outer members (520, 520a, 520b) can be moved while being pressed by a plurality of upper rolls and lower rolls arranged at the rear end of the first roll forming unit, with the first flange (512, 512a, 512b, 513, 513a, 513b) and the second flange (522, 522a, 522b, 523, 523a, 523b) in a one-to-one contact state.

[0206] In this process, the first flange (512, 512a, 512b, 513, 513a, 513b) and the second flange (522, 522a, 522b, 523, 523a, 523b) can be joined by the joining unit. For example, the joining unit can perform a joining process to form a first weld (Wb1) by using a joining laser welding method (i.e., a first joining method) in which a laser beam is irradiated into a first region (A10, A15, A16) formed by the contact of the first flange (112, 212, 312, 412, 512a, 512b) and the second flange (522, 522a, 522b, 523, 523a, 523b).

[0207] In this manner, a single long structure having a closed cross-section can be formed. Subsequently, a front side rail (RS1) and a rear side rail (SR2) having a predetermined length can be manufactured by cutting the aforementioned single structure at a position corresponding to the narrow section to adjust the length. By reassembling the front side rail (RS1) and the rear side rail (SR2) manufactured by cutting in this way, various types of side rails (RS) can be manufactured.

[0208] Through the single roll forming process described above, a single structure having the same closed cross-section can be rapidly manufactured, and by using a method of cutting and reassembling the manufactured long single structure, it is possible to manufacture various types of side rails (RS). By doing so, productivity can be improved during mass production of the vehicle body frame unit (10).

[0209] The side rails (RS, RSa, RSb, RSc, RSd, RSe, RSf) according to Examples 1 to 7 as described above are exemplary, and the present invention is not limited by these examples.

[0210] In the case of the present invention, the side rail (RS) is a structure in which an inner member (510) and an outer member (520) are mutually joined to form a closed cross-section, and each of the inner member (510) and the outer member (520) is provided with two flanges (512, 513, 522, 523), and it is sufficient that the inner member (510) or the outer member (520) includes at least one bent portion.

[0211] That is, the shape of the first body (511) and the second body (521), the length of the first flange (512, 513) and the second flange (522, 523), and the length or position of the bending portion may be changed based on the type, shape, and size of the vehicle on which the side rail (RS) is installed. The side rail (RS) according to the present invention having such features can be manufactured by the roll forming device and roll forming method described above.

[0212] As described above, the side rail (RS) and body frame unit (10) according to the embodiments of the present invention are formed by distinguishing between a first area (A10), which is an area where an inner member (510) and an outer member (520) are mutually coupled, and a second area (A20), which is an area where a part such as a side outer (SO) is additionally coupled, thereby reducing the number of welding layers when additionally coupling parts.

[0213] As a result, welding defects and strength reduction caused by an excessive increase in the number of welding layers, such as 4-layer welding, can be prevented. In addition, additional processing such as trimming of outer panel parts to avoid 4-layer welding becomes unnecessary, and while sufficient strength is secured, the weight of the side rail (RS) can be reduced.

[0214] In addition, by forming the side rail (RS) in a shape having a closed cross-section of the same shape and size throughout along its extension direction, it is possible to easily implement changes in the shape of the side rail (RS) in response to various shapes of the vehicle body, thereby ensuring improved productivity and cost reduction during mass production of the vehicle body or the side rail (RS).

[0215] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A vehicle side rail that is positioned at the upper part of a vehicle body frame unit and supports the roof, An inner member comprising a first flange having a first length and protruding outwardly from one end; and An outer member comprising a second flange that protrudes outward from one end and faces the first flange and has a second length different from the first length; The inner member and the outer member are, The first flange and the second flange are joined in contact with each other to form a closed cross-section, and the closed cross-section extends with the same area along the extension direction of the side rail. At least one of the first flange and the second flange is, A vehicle side rail characterized by including a bend portion at one end that is bent in a bending direction inclined with respect to the extension direction.

2. In Paragraph 1, The first flange and the second flange are each provided in two numbers, The two first flanges are respectively positioned at the upper and lower ends of the inner member, and A vehicle side rail, wherein the two second flanges are respectively positioned at the upper and lower ends of the outer member and face the first flange in a one-to-one manner.

3. In Paragraph 2, When the inner member and the outer member are combined, A vehicle side rail having a first area in which the first flange and the second flange are arranged together so as to overlap, and a second area in which only one of the first flange and the second flange is arranged.

4. In Paragraph 3, A vehicle side rail, wherein the second region has a longer length than the first region.

5. In Paragraph 4, The above-mentioned bent portion is, A vehicle side rail disposed in the second area disposed at the upper portion of the inner member or the outer member.

6. In Paragraph 2, The above inner member is, It includes a first bend portion disposed at the upper end of the inner member and bent in the bending direction, The above outer member is, A vehicle side rail comprising a second bend portion having a length different from that of the first bend portion, which is positioned at the upper end of the outer member and bent in the bending direction.

7. In Paragraph 6, When the inner member and the outer member are combined, A vehicle side rail having a first area in which the first bend portion and the second bend portion are arranged together so as to overlap, and a second area in which only one of the first bend portion and the second bend portion is arranged.

8. In Paragraph 3 or Paragraph 7, A vehicle side rail, wherein the length of the first region is 2 to 7 mm.

9. In Paragraph 3 or Paragraph 7, A vehicle side rail, wherein the length of the second region is 10 to 15 mm.

10. In Paragraph 3 or Paragraph 7, The first flange and the second flange are joined in the first area by a first joining method, A vehicle side rail in which at least one of a roof panel and a side outer is joined using a second joining method in the second region.

11. In Paragraph 10, The second region is formed on each side of the inner member or the outer member, respectively. The above side outer is, A vehicle side rail, wherein one end is coupled to a second region formed on either side of the inner member or the outer member, and the other end is coupled to a second region formed on the other side of the inner member or the outer member, thereby covering the outer side of the side rail.

12. In Paragraph 10, A vehicle side rail, wherein the first joining method is a laser welding method and the second joining method is a spot welding method.

13. A side rail according to any one of claims 1 to 12, which is positioned on the side of the vehicle body and supports the roof; A side sill positioned below the side rail and supporting the lower part of the vehicle body; and A body frame unit comprising: a pillar section disposed between the side rail and the side sill and including a plurality of pillars.

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