Front side member for vehicle

Abstract

The present invention relates to a front side member for a vehicle that can effectively support a front collision load and improve the rigidity of the vehicle body, the front side member for the vehicle including an outer wall, an inner wall positioned opposite the outer wall, an outer bead formed on the outer wall along the longitudinal direction of the vehicle body and having a first groove surface, and an inner bead formed on the inner wall along the longitudinal direction of the vehicle body and having a second groove surface, the outer bead including a region where a bead depth, which is the distance between the outer wall and the first groove surface, changes along the longitudinal direction of the vehicle body, and the inner bead including a region where a bead depth, which is the distance between the inner wall and the second groove surface, changes along the longitudinal direction of the vehicle body.

Description

[Technical field]

[0001] The present invention relates to a vehicle front side member that constitutes a front structure of a vehicle body. [Background technology]

[0002] Generally, in a front structure of a vehicle body, a front side member is disposed parallel to an axis in the longitudinal direction of the vehicle body.

[0003] In this case, for example, in the event of a small overlap collision (when only 25% of the vehicle's width on the driver's or passenger's side hits an obstacle at a speed of 64 km / h), the front side member is unable to absorb the collision energy.

[0004] This calls for improving the impact absorption capacity of the front side members.

[0005] Related prior art includes the invention disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent No. 2129696(B1) Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a front side member for a vehicle that can effectively support a front collision load and improve the rigidity of the vehicle body. [Means for solving the problem]

[0008] A vehicle front side member according to one embodiment of the present invention includes an outer wall, an inner wall positioned opposite the outer wall, an outer bead formed on the outer wall along the length of a vehicle body and having a first groove surface, and an inner bead formed on the inner wall along the length of the vehicle body and having a second groove surface, wherein the outer bead includes a region where a bead depth, which is the distance between the outer wall and the first groove surface, changes along the length of the vehicle body, and the inner bead includes a region where a bead depth, which is the distance between the inner wall and the second groove surface, changes along the length of the vehicle body. Effect of the Invention

[0009] According to the present invention, the deformation behavior of the front side member in a full frontal collision is excellent, and the collision energy can be effectively absorbed.

[0010] Furthermore, according to the present invention, it is possible to maximize the vehicle's widthwise behavior in a small overlap collision, thereby improving the collision performance of the vehicle body. [Brief description of the drawings]

[0011] [Figure 1] 1 is a bottom view showing a front structure of a vehicle body to which a front side member for a vehicle according to the present invention is applied; [Diagram 2] 1 is a perspective view showing a pair of vehicle front side members according to a first embodiment of the present invention. [Diagram 3] 1 is a plan view showing a vehicle front side member according to a first embodiment of the present invention. [Figure 4] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Diagram 5] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 6] FIG. 3 is a cross-sectional view taken along line CC in FIG. [Figure 7] FIG. 11 is a plan view showing a vehicle front side member according to a second embodiment of the present invention. [Figure 8]6 is a cross-sectional view showing a vehicle front side member according to a third embodiment of the present invention, the view showing a portion corresponding to FIG. 5. [Figure 9] 7 is a cross-sectional view showing a vehicle front side member according to a third embodiment of the present invention, and is a drawing of a portion corresponding to FIG. 6. [Figure 10] FIG. 11 is a perspective view showing a pair of vehicle front side members according to a fourth embodiment of the present invention. [Figure 11] FIG. 11 is an exploded perspective view of a vehicle front side member according to a fourth embodiment of the present invention. [Figure 12] FIG. 11 is a plan view showing a vehicle front side member according to a fourth embodiment of the present invention. [Figure 13] FIG. 11 is a cross-sectional view taken along line DD in FIG. [Figure 14] FIG. 11 is a cross-sectional view taken along line EE in FIG. [Figure 15] FIG. 11 is a cross-sectional view taken along the line FF in FIG. [Figure 16] 14 is a cross-sectional view showing a vehicle front side member according to a fifth embodiment of the present invention, the view showing a portion corresponding to FIG. 13. [Figure 17] 14 is a cross-sectional view showing a vehicle front side member according to a sixth embodiment of the present invention, the view showing a portion corresponding to FIG. 13. [Figure 18] 4 is a graph showing deformation forms of a front side member for a vehicle according to the present invention and a related art, which are analyzed during a full frontal collision. [Figure 19] 4 is a graph showing deformation forms of a front side member for a vehicle according to the present invention and a related art, which are analyzed during a full frontal collision. [Figure 20] 4 is a graph showing deformation patterns of a vehicle front side member according to the present invention and a conventional technology in a small overlap collision. [Figure 21] 4 is a graph showing deformation patterns of a vehicle front side member according to the present invention and a conventional technology in a small overlap collision. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the present invention will be described in detail with reference to exemplary drawings. When adding reference symbols to components in each drawing, it should be noted that the same components are given the same symbols as much as possible even when they are displayed in other drawings. In addition, in the description of the present invention, if it is determined that a specific description of related known configurations or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0013] In the following description, terms used in relation to directions, such as "forward," "front," "rear," "upper," "lower," "left / right," "inner," "outer," "inside," and "outside," are defined with reference to the vehicle or vehicle body.

[0014] A vehicle front side member is made up of a front side member inner panel and a front side member outer panel. In this specification, for convenience of explanation, the front side member outer panel is referred to as a side outer panel, and the front side member inner panel is referred to as a side inner panel.

[0015] In this specification, a vehicle refers to various devices that move objects to be transported, such as people, animals, goods, etc., from a starting point to a destination. Such vehicles are not limited to vehicles that run on roads or tracks.

[0016] Furthermore, a vehicle traveling on a road or railroad can move in a predetermined direction in response to the rotation of at least one wheel, and may include, for example, three- or four-wheeled automobiles, construction machinery, two-wheeled automobiles, prime movers, trains traveling on railroad tracks, etc.

[0017] FIG. 1 is a bottom view showing a front structure of a vehicle body to which a vehicle front side member of the present invention is applied, FIG. 2 is a perspective view showing a pair of vehicle front side members according to a first embodiment of the present invention, and FIG. 3 is a plan view showing a vehicle front side member according to the first embodiment of the present invention.

[0018] The vehicle's frame structure can be composed of two side members 1 that extend in the longitudinal direction X of the vehicle body and form the sides of the vehicle body, and a cross member 2 that extends in the width direction Y of the vehicle body and is connected to both side members.

[0019] A plurality of cross members 2 may be connected to the side members 1 at intervals from the front end to the rear end of the vehicle body. The side members may be called front side members 10, rear side members, etc., depending on the position where the cross members are connected or the position of the floor panel. Meanwhile, side seals 30 that protect the passenger space in the event of a side collision and define the outline of the side may be provided on the side of the vehicle.

[0020] For example, in the case of an electric vehicle, a battery (not shown) can be mounted on the vehicle body, and for this purpose, a battery space 40 in which the battery is mounted can be provided. A floor panel (not shown) that partitions a passenger space in which passengers board can be provided above the battery space 40.

[0021] The vehicle front side members 10 according to the first embodiment of the present invention are provided in a pair and can be disposed on both the left and right sides in the width direction Y of the vehicle body while extending along the length direction X of the vehicle body.

[0022] 1 and 2, the front side members 10 may be disposed inclined at an angle to an axis O extending in the longitudinal direction X of the vehicle body rather than parallel to the axis O. More specifically, the two front side members 10 may be disposed closer to each other toward the rear.

[0023] The inclined position of the front side member 10 is due to the fact that both ends of the bumper beam 50 have a curvature toward the rear, and the collision load applied to the front side member is applied at an angle; by setting the angle of the front side member so that it is approximately parallel to the direction of the collision load in this manner, the collision load can be transmitted as maximized as possible.

[0024] In addition, the front side member 10 may be connected to the bumper beam 50 such that the center point of one end connected to the bumper beam 50, i.e., the front end, is located at a position between 20% to less than 30% from the outside to the inside of the overall vehicle width W.

[0025] For example, if the front side member 10 is connected to the bumper beam 50 at a position corresponding to 25% from the outside to the inside of the overall vehicle width W, the front side member can play a role in resisting the collision load during a small overlap collision.

[0026] The front side member 10 can effectively transmit the collision load that enters the front side member from the bumper beam 50 to the vehicle body via the front cross member 20 and the like.

[0027] In addition, in a small overlap collision, the front side member 10 can play a role such as enhancing the behavior of the vehicle in the width direction.

[0028] Meanwhile, the inclined front side member 10 may have weakened collision performance in comparison with the parallel front side member in a 40% offset collision or a full frontal collision because the inclined front side member does not deform to absorb the collision energy to the maximum extent in the 40% offset collision or full frontal collision conditions, but simply buckles.

[0029] For convenience, only one of the two front side members 10 will be described below. The other of the two front side members may symmetrically include the configuration of the described front side member and may be symmetrically arranged.

[0030] As shown in FIGS. 2 and 3, the vehicle front side member 10 according to the first embodiment of the present invention may include an outer wall 11, an inner wall 12, an outer bead 110 and an inner bead 120.

[0031] The outer wall 11 and the inner wall 12 form a front side member 10 and may extend linearly, preferably straight, along the longitudinal direction X of the vehicle body. One end, i.e., the front end, of the outer wall and the inner wall may be connected to the bumper beam 50, and the other end, i.e., the rear end, may be connected to the front surface of a front cross member 20 of the vehicle body extending in the transverse direction Y of the vehicle body or the front surface of a dash panel 21.

[0032] The outer wall 11 and the inner wall 12 may form a tubular member having a polygonal cross-sectional shape, such as a rectangle. The cross-sectional shape of the tubular member is not necessarily limited thereto. The tubular member may be formed of a single plate material or may be formed by joining two or more plates.

[0033] When the tubular member is formed by joining two or more plate materials, the tubular member may include a side outer panel 13 and a side inner panel 14. The upper and lower ends of the side outer panel and the side inner panel may each be provided with a flange F formed by bending.

[0034] A tubular member having a closed cross section can be produced by welding and joining the side inner panel 14 to one side of the side outer panel 13. The side outer panel and the side inner panel can be joined by applying welding such as spot welding, laser welding, etc. to applicable portions including the flange F.

[0035] This allows the outer wall 11 to be provided on the side outer panel 13, and the inner wall 12 to be provided on the side inner panel 14.

[0036] In the vehicle front side member 10 according to the first embodiment of the present invention, the outer wall 11 and the inner wall 12 can be disposed at a first angle a with respect to the longitudinal axis O of the vehicle body due to the inclined arrangement of the front side member. The first angle has a range of approximately 5 to 10 degrees.

[0037] The outer bead 110 may be formed on the outer wall 11 so as to extend along the longitudinal direction X of the vehicle body. For example, the outer bead may have a length extending from the front end of the outer wall toward the rear end thereof, the length being more than half the length of the outer wall.

[0038] The inner bead 120 may be formed on the inner wall 12 to extend along the longitudinal direction X of the vehicle body. For example, the inner bead may have a length that extends from the front end to the rear end of the inner wall more than half the length of the inner wall.

[0039] 4 is a cross-sectional view taken along line AA in FIG. 2, FIG. 5 is a cross-sectional view taken along line BB in FIG. 2, and FIG. 6 is a cross-sectional view taken along line CC in FIG.

[0040] 4 to 6, the outer bead 110 may include a first groove surface 112 connecting between the groove walls 111. The outer bead may also have a first bead depth D1, which is the distance between the outer wall 111 and the first groove surface.

[0041] The inner bead 120 can include a second groove surface 122 connecting between the groove walls 121. Additionally, the inner bead can have a second bead depth D2, which is the distance between the inner wall 121 and the second groove surface.

[0042] 4 to 6 together with FIG. 3, in the vehicle front side member 10 according to the first embodiment of the present invention, the outer bead 110 can include a region in which the first bead depth D1 changes along the longitudinal direction X of the vehicle body.

[0043] In the vehicle front side member 10 according to the first embodiment of the present invention, the inner bead 120 may include a region in which the second bead depth D2 changes along the longitudinal direction X of the vehicle body.

[0044] Thus, the first groove surface 112 of the outer bead 110 may include a first inclined surface 113 inclined at a second angle b with respect to the longitudinal axis O of the vehicle body. The first groove surface of the outer bead may also include a second inclined surface 114 inclined at a third angle c with respect to the longitudinal axis O of the vehicle body. Here, the third angle c may be greater than the second angle b and the first angle a.

[0045] The second groove surface 122 of the inner bead 120 may include a third inclined surface 123 inclined at a second angle b relative to the longitudinal axis O of the vehicle body. The second groove surface of the inner bead may also include a fourth inclined surface 124 inclined at a fourth angle d relative to the longitudinal axis O of the vehicle body. Here, the fourth angle d may be greater than the second angle b and the first angle a.

[0046] The second angle b between the first inclined surface 113 of the outer bead 110 and the third inclined surface 123 of the inner bead 120 is in the range of about 0 to 3 degrees. This allows the first inclined surface of the outer bead and the third inclined surface of the inner bead to be arranged parallel or nearly parallel to the longitudinal axis O of the vehicle body.

[0047] The second angle b that the outer bead 110 and the inner bead 120 have with respect to the longitudinal axis O of the vehicle body can be smaller than the first angle a that the outer wall 11 and the inner wall 12 have with respect to the longitudinal axis O of the vehicle body due to the inclined arrangement of the front side member 10.

[0048] Because of this configuration, the vehicle front side member 10 according to the first embodiment of the present invention can form a closed cross section at the rear end portion, without a bead, between the outer wall 11 and the inner wall 12, as shown in FIG. 4, for example.

[0049] Next, for example, as shown in FIG. 5, the front side member 10 may be formed such that the second bead depth D2 of the inner bead 120 and the first bead depth D1 of the outer bead 110 are the same as each other at the middle, or the second bead depth is deeper than the first bead depth.

[0050] Next, for example, as shown in FIG. 6, the front side member 10 may be formed such that the second bead depth D2 of the inner bead 120 gradually becomes shallower toward the front end, and the first bead depth D1 of the outer bead 110 gradually becomes deeper toward the front end.

[0051] In other words, the first bead depth D1 of the outer bead 110 may gradually become deeper toward the front of the vehicle body. Conversely, the second bead depth D2 of the inner bead 120 may gradually become shallower from the third inclined surface 123 toward the front of the vehicle body.

[0052] In the vehicle front side member 10 according to the first embodiment of the present invention, the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120 can be in contact with each other. Specifically, the first inclined surface 113 of the outer bead and the third inclined surface 123 of the inner bead can be in contact with each other.

[0053] A weld or an adhesive layer may be formed between the first groove surface 112 and the second groove surface 122 that are in contact with each other. The weld may be formed by welding such as spot welding, laser welding, etc. The adhesive layer may be formed by an adhesive such as a structural adhesive.

[0054] However, this is not necessarily limited thereto. For example, the first groove surface 112 and the second groove surface 122 may simply be placed against each other or joined by rivets or the like without a weld or adhesive layer.

[0055] The tubular member, or the side outer panel 13 and the side inner panel 14, may be made of a metal material such as steel, and may be formed together with the outer bead 110 and the inner bead 120 by forming or bending using a press, roll forming, or a combination thereof.

[0056] More specifically, for example, the side outer panel 13 and the side inner panel 14 can be made of plate material such as 980DP (Dual Phase) steel, 980XF (EXtra Formability) steel, or 1180TRIP (Transformation Induced Plasticity) steel having a thickness of approximately 1.2 mm to 2.0 mm produced by the present applicant.

[0057] Here, 980DP steel is a steel type that has a tensile strength of 980 MPa or more, a low yield ratio, can be easily processed, and exhibits high elongation. 980XF steel is a steel type that has a tensile strength of 980 MPa or more and a yield strength of 600 MPa or more, and exhibits high elongation. 1180TRIP steel is a steel type that has an elongation rate improved to 45% or more while guaranteeing a tensile strength of 1180 MPa or more and a yield strength of 850 MPa or more.

[0058] For example, 980DP steel, 980XF steel, or 1180TRIP steel may be used alone or in combination for the side outer panel 13 and the side inner panel 14. In this manner, the impact absorbing capacity of the front side member 10 can be maximized by combining the strengths of the plate materials that form the front side member 10.

[0059] When manufacturing the side outer panel 13 and the side inner panel 14 by roll forming, it is possible to easily form ultra-high strength steel material with a tensile strength of approximately 590 MPa or more. Furthermore, roll forming has the advantage that it is easier to correct springback than press forming, and the corner radius of the side outer panel and side inner panel can be made smaller.

[0060] On the other hand, when the tubular member is formed of a single plate material, the front side member 10 can be formed together with the outer bead 110 and the inner bead 120 via hydroforming or any machining process.

[0061] When forming the front side member 10 by hydroforming, it is possible to easily form ultra-high strength steel material with a tensile strength of approximately 590 MPa or more. Furthermore, by using ultra-high strength steel material, further weight reduction can be ensured.

[0062] In addition, applying hydroforming to steel materials can reduce manufacturing costs by reducing the number of welding steps required during part production, and at the same time, the use of steel materials can dramatically reduce the material ratio to aluminum.

[0063] In the vehicle front side member 10 according to the first embodiment of the present invention, first, an outer bead 110 of the outer wall 11 and an inner bead 120 of the inner wall 12 are formed, thereby improving the rigidity of the vehicle body or the front side member in the longitudinal direction X, thereby increasing the amount of load that can be absorbed.

[0064] Furthermore, due to its inclined arrangement, the vehicle front side member 10 of the first embodiment of the present invention is able to transmit collision loads to the rear of the vehicle body not only in a full frontal collision of the vehicle but also in a small overlap collision, and can bring out the vehicle's widthwise behavior in a small overlap collision, thereby improving the collision performance of the vehicle body.

[0065] For example, in the case of electric vehicles, the weight of the vehicle increases due to the installation of batteries, and the space in the body is reduced, but the vehicle still has the advantage of ensuring crashworthiness and safety. This may lead to improved marketability of the vehicle.

[0066] FIG. 7 is a plan view showing a vehicle front side member according to a second embodiment of the present invention.

[0067] 7 differs only in the shape of the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120, and the other components are the same as those of the first embodiment described above. Therefore, in describing the vehicle front side member 10 according to the second embodiment of the present invention, the same components as those of the vehicle front side member according to the first embodiment described above are given the same reference numerals, and detailed description of the configurations and functions thereof will be omitted.

[0068] In the vehicle front side member 10 according to the second embodiment of the present invention, the outer bead 110 may include a region in which the first bead depth D1 changes along the length direction X of the vehicle body.

[0069] In the vehicle front side member 10 according to the second embodiment of the present invention, the inner bead 120 may include a region in which the second bead depth D2 changes along the length direction of the vehicle body.

[0070] Accordingly, the first groove surface 112 of the outer bead 110 may include a first inclined surface 113 inclined at a second angle b with respect to the longitudinal axis O of the vehicle body. Also, the first groove surface of the outer bead may include a second inclined surface 114 inclined at a third angle c with respect to the longitudinal axis O of the vehicle body. Here, the third angle c may be greater than the second angle b and the first angle a.

[0071] The first groove surface 112 of the outer bead 110 may further include a first connecting surface 115 connecting the first inclined surface 113 and the second inclined surface 114. The first connecting surface extends parallel to the outer wall within the outer bead along the longitudinal direction X of the vehicle body.

[0072] The second groove surface 122 of the inner bead 120 may include a third inclined surface 123 inclined at a second angle b relative to the longitudinal axis O of the vehicle body. The second groove surface of the inner bead may also include a fourth inclined surface 124 inclined at a fourth angle d relative to the longitudinal axis O of the vehicle body. Here, the fourth angle d may be greater than the second angle b and the first angle a.

[0073] The second groove surface 122 of the inner bead 120 may further include a second connecting surface 125 connecting the third inclined surface 123 and the fourth inclined surface 124. The second connecting surface extends parallel to the inner wall within the inner bead along the longitudinal direction X of the vehicle body.

[0074] The second angle b of the first inclined surface 113 of the outer bead 110 and the third inclined surface 123 of the inner bead 120 has a range of about 0 to 3 degrees. In Fig. 7, the second angle b is omitted since it is almost 0 degrees. This allows the first inclined surface of the outer bead and the third inclined surface of the inner bead to be arranged parallel or almost parallel to the longitudinal axis O of the vehicle body.

[0075] The second angle b that the outer bead 110 and the inner bead 120 have with respect to the longitudinal axis O of the vehicle body can be smaller than the first angle a that the outer wall 11 and the inner wall 12 have with respect to the longitudinal axis O of the vehicle body due to the inclined arrangement of the front side member 10.

[0076] As described above, since the outer bead 110 and the inner bead 120 each include a region where the bead depth changes along the longitudinal direction X of the vehicle body, in the vehicle front side member 10 according to the second embodiment of the present invention, the first bead depth D1 of the outer bead may become deeper from the connecting point of the first connecting surface 115 and the first inclined surface 113 toward the front of the vehicle body. Conversely, the second bead depth D2 of the inner bead becomes shallower from the connecting point of the second connecting surface 125 and the third inclined surface 123 toward the front of the vehicle body.

[0077] In the vehicle front side member 10 according to the second embodiment of the present invention, the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120 can be in contact with each other. Specifically, the first inclined surface 113 of the outer bead and the third inclined surface 123 of the inner bead can be in contact with each other, and the first connecting surface 115 of the outer bead and the second connecting surface 125 of the inner bead can be in contact with each other.

[0078] A weld or an adhesive layer may be formed between the first groove surface 112 and the second groove surface 122 that are in contact with each other. The weld may be formed by welding such as spot welding, laser welding, etc. The adhesive layer may be formed by an adhesive such as a structural adhesive.

[0079] However, this is not necessarily limited thereto. For example, the first groove surface 112 and the second groove surface 122 may simply be placed against each other or joined by rivets or the like without a weld or adhesive layer.

[0080] FIG. 8 is a cross-sectional view showing a vehicle front side member according to a third embodiment of the present invention, and is a drawing of a portion corresponding to FIG. 5, and FIG. 9 is a cross-sectional view showing a vehicle front side member according to the third embodiment of the present invention, and is a drawing of a portion corresponding to FIG. 6.

[0081] 8 and 9, the only difference is that the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120 are spaced apart from each other, and the other components are the same as those of the first or second embodiment described above. Therefore, in describing the vehicle front side member 10 according to the third embodiment of the present invention, the same components as those of the vehicle front side member according to the first or second embodiment described above are given the same reference numerals, and detailed description of the configurations and functions thereof will be omitted.

[0082] In the vehicle front side member 10 according to the third embodiment of the present invention, the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120 may be spaced apart from each other. Specifically, the first inclined surface 113 of the outer bead and the third inclined surface 123 of the inner bead may be formed and arranged to be spaced apart from each other at a regular interval.

[0083] Alternatively, the first connecting surface 115 of the outer bead 110 and the second connecting surface 125 of the inner bead 120 may be formed and disposed at a predetermined distance from each other.

[0084] In this way, the outer bead 110 has a first groove surface 112 and the inner bead 120 has a second groove surface 122, which are spaced apart from each other, so that the outer bead and the inner bead do not need to be molded deeply. This makes it easy to mold the outer bead and the inner bead, and reduces the man-hours and costs required for welding, bonding, riveting, etc., to join the groove surfaces.

[0085] Of course, even if the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120 are separated in this manner, the outer bead and the inner bead act as reinforcing means within the front side member 10, so that the front side member can effectively resist a frontal collision applied from the outside.

[0086] FIG. 10 is a perspective view showing a pair of vehicle front side members according to a fourth embodiment of the present invention, FIG. 11 is an exploded perspective view of the vehicle front side member according to the fourth embodiment of the present invention, and FIG. 12 is a plan view showing the vehicle front side member according to the fourth embodiment of the present invention.

[0087] As shown in Figures 10 to 12, the vehicle front side member 10 according to the fourth embodiment of the present invention can include an outer wall 11, an inner wall 12, an outer bead 110, an inner bead 120, an outer rear 15, an inner rear 16, and a reinforcing material 17.

[0088] The outer wall 11 and the inner wall 12 form a front side member 10 and may extend linearly, preferably straight, along the longitudinal direction X of the vehicle body. One end of the outer wall and the inner wall, i.e., the front end, may be connected to a bumper beam 50 (see FIG. 1), and the other end, i.e., the rear end, may be connected to an outer rear 15 or an inner rear 16, or the outer rear and the inner rear.

[0089] The outer wall 11 and the inner wall 12 may form a tubular member having a polygonal cross-sectional shape, such as a rectangle. The cross-sectional shape of the tubular member is not necessarily limited thereto. The tubular member may be formed of a single plate material or by joining two or more plates.

[0090] Hereinafter, the vehicle front side member 10 according to the fourth embodiment of the present invention will be described with reference to the case where the tubular member is formed by joining two or more plate materials for the convenience of explanation and illustration. The same configuration and connection relationship can be applied even when the tubular member is formed of a single plate material.

[0091] The tubular member may include a side outer panel 13 and a side inner panel 14. The upper and lower ends of the side outer panel and the side inner panel may each be provided with a flange F formed by bending.

[0092] A tubular member having a closed cross section can be produced by welding and joining the side inner panel 14 to one side of the side outer panel 13. The side outer panel and the side inner panel can be joined by applying welding such as spot welding, laser welding, etc. to applicable portions including the flange F.

[0093] This allows the outer wall 11 to be provided on the side outer panel 13, and the inner wall 12 to be provided on the side inner panel 14.

[0094] The outer rear 15 may be connected to the rear end of the side outer panel 13 so as to branch out and extend in a direction different from the extension direction of the side outer panel. A front portion of the outer rear may extend parallel to the side outer panel by a certain length, and a rear portion may be bent or curved at a predetermined angle relative to the front portion.

[0095] As a result, one side of the front end of the outer rear 15 can be fixed to a side of the side outer panel 13, or a flange F of the outer rear can be fixed to a flange of the side outer panel by welding such as spot welding or laser welding. However, this is not necessarily limited thereto, and for example, the outer rear can be molded continuously and integrally with the side outer panel and extend linearly following the side outer panel.

[0096] The outer rear 15 can be formed separately using machining such as stamping or roll forming, or can be integrally formed when the side outer panel 13 is formed.

[0097] An auxiliary bead 19 may be formed in a front portion of the outer rear 15 as a shape corresponding to a part of the outer bead 110 of the outer wall 11. The auxiliary bead may reinforce the rigidity of not only the outer rear but also the side outer panel 13, so that the outer rear may be stably joined to the outer wall or the side outer panel.

[0098] The rear end of the outer rear 15 can be connected to a side seal 30 (see FIG. 1) and a front cross member 20 (see FIG. 1) that extend in the longitudinal direction X of the vehicle body. This allows the front side member 10 to reliably transmit a collision load to the side seal and the front cross member via the outer rear.

[0099] An inner rear 16 may extend from the rear end of the side inner panel 14. The inner rear may have a folded or curved cross-sectional shape to have an open cross-section.

[0100] As a result, one side of the front end of the inner rear 16 can be fixed to the side of the side inner panel 14 by welding, such as spot welding, laser welding, etc. However, this is not necessarily limited thereto, and for example, the inner rear can be molded integrally with the side inner panel, and extend linearly following the side inner panel.

[0101] The inner rear 16 can be formed separately using machining such as stamping or roll forming, or can be formed integrally with the side inner panel 14 when the side inner panel 14 is formed.

[0102] A rear end of the inner rear 16 can be connected to the front surface of a front cross member 20 (see FIG. 1) that extends in the width direction Y of the vehicle body and the front surface of a dash panel 21.

[0103] Also, a rear portion of the inner rear 16 may be bent downward to form a curved portion 18. For example, the curved portion may come into contact with the front surface of the dash panel 21, and one side of an end of the curved portion may come into surface contact with the front surface of the front cross member 20 and be fixed, for example, by welding. This allows the front side member 10 to reliably transmit a collision load to at least the front cross member via the inner rear.

[0104] In the vehicle front side member 10 according to the fourth embodiment of the present invention, the collision performance of the front side member can be ensured by adjusting the material of the plate material constituting the outer rear 15 and the inner rear 16 and the strength of this material. For example, by using ultra-high strength steel of 980 MPa class or more, an optimal combination for rigidity and weight reduction of the front side member can be achieved.

[0105] More specifically, the outer rear 15 and the inner rear 16 can be made of a plate material such as 1470HPF (Hot Press Forming) steel produced by the present applicant. Here, 1470HPF steel is a type of steel that can obtain a tensile strength of 1,470 MPa or more while at the same time allowing the shape of the part to be freely created.

[0106] The outer rear 15 may be formed of a material having a strength higher than that of the outer side wall 11. The inner rear 16 may be formed of a material having a strength higher than that of the inner side wall 12.

[0107] In this manner, by combining the strengths of the plate materials that form the front side member 10, the impact absorbing capacity of the front side member can be maximized.

[0108] In addition, the outer rear 15 may be formed to be thicker than the outer side wall 11. The inner rear 16 may be formed to be thicker than the inner side wall 12.

[0109] In this way, the outer rear 15 and the inner rear 16, which are relatively thicker than the outer wall 11 and the inner wall 12, can strengthen the support rigidity of the front side member 10 itself during a frontal collision of the vehicle. This enables the outer rear and the inner rear to maximize the impact absorption capacity of the front side member.

[0110] Meanwhile, a subframe (not shown) of a suspension may be fastened to the front end of the front side member 10, and the front end of the front side member may be vulnerable to a vertical load. Therefore, a reinforcement member 17 may be selectively attached to the front end of the outer wall 11.

[0111] The reinforcement 17 may be connected to the bumper beam 50 together with the outer wall. Also, the reinforcement may have at least one welding through hole 17a formed therein. For example, a spot welder may pass through the welding through hole to perform welding between a first groove surface 112 of the outer bead 110 and a second groove surface 122 of the inner bead 120, which will be described later.

[0112] 13 is a cross-sectional view taken along line DD in FIG. 10, FIG. 14 is a cross-sectional view taken along line EE in FIG. 10, and FIG. 15 is a cross-sectional view taken along line FF in FIG.

[0113] 13 to 15, the outer bead 110 may include a first groove surface 112 connecting between the groove walls 111. The outer bead may also have a first bead depth D1, which is the distance between the outer wall 111 and the first groove surface.

[0114] The inner bead 120 can include a second groove surface 122 connecting between the groove walls 121. The inner bead can also have a second bead depth D2, which is the distance between the inner wall 121 and the second groove surface.

[0115] 13 to 15 together with FIG. 12, in a vehicle front side member 10 according to a fourth embodiment of the present invention, the outer bead 110 can include a region in which the first bead depth D1 changes along the longitudinal direction X of the vehicle body.

[0116] In the vehicle front side member 10 according to the fourth embodiment of the present invention, the inner bead 120 may include a region in which the second bead depth D2 changes along the length direction X of the vehicle body.

[0117] Accordingly, the first groove surface 112 of the outer bead 110 may include a first inclined surface 113 inclined at a second angle b with respect to the longitudinal axis O of the vehicle body. Also, the first groove surface of the outer bead may include a second inclined surface 114 inclined at a third angle c with respect to the longitudinal axis O of the vehicle body. Here, the third angle c may be greater than the second angle b and the first angle a.

[0118] The second groove surface 122 of the inner bead 120 can include a third angled surface 123 disposed at a second angle b relative to the longitudinal axis O of the vehicle body. For example, the third angled surface can extend from the forward end to the aft end of the inner wall.

[0119] The second angle b between the first inclined surface 113 of the outer bead 110 and the third inclined surface 123 of the inner bead 120 is in the range of about 0 to 3 degrees. This allows the first inclined surface of the outer bead and the third inclined surface of the inner bead to be arranged parallel or nearly parallel to the longitudinal axis O of the vehicle body.

[0120] The second angle b that the outer bead 110 and the inner bead 120 have with respect to the longitudinal axis O of the vehicle body can be smaller than the first angle a that the outer wall 11 and the inner wall 12 have with respect to the longitudinal axis O of the vehicle body due to the inclined arrangement of the front side member 10.

[0121] 13, the second bead depth D2 of the inner bead 120 at the rear end is the deepest, whereas the outer wall 11 can be formed without a bead. Also, the inner rear 16 can be disposed overlapping the inner wall 12, and the outer rear 15 can be disposed apart from the outer wall 11.

[0122] 14, the front side member 10 may have a second bead depth D2 of the inner bead 120 and a first bead depth D1 of the outer bead 110 that are equal to each other or may have a second bead depth deeper than the first bead depth. Also, the outer rear 15 may be disposed adjacent to or overlapping the outer wall 11 at the rear end.

[0123] 15, the front side member 10 may be formed such that the second bead depth D2 of the inner bead 120 becomes gradually shallower toward the front end, and the first bead depth D1 of the outer bead 110 becomes gradually deeper toward the front end. Also, the reinforcement 17 may be provided at the front end of the outer wall 11 across the outer bead 110.

[0124] In other words, the outer bead 110 may have a first bead depth D1 that gradually becomes deeper toward the front of the vehicle body, and conversely, the inner bead 120 may have a second bead depth D2 that gradually becomes shallower toward the front of the vehicle body.

[0125] In a vehicle front side member 10 according to a fourth embodiment of the present invention, as shown in Fig. 13 to Fig. 15, the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120 can be in contact with each other. Specifically, the first inclined surface 113 of the outer bead and the third inclined surface 123 of the inner bead can be in contact with each other.

[0126] A weld or an adhesive layer may be formed between the first groove surface 112 and the second groove surface 122 that are in contact with each other. The weld may be formed by welding such as spot welding, laser welding, etc. The adhesive layer may be formed by an adhesive such as a structural adhesive.

[0127] However, this is not necessarily limited thereto, and for example, the first groove surface 112 and the second groove surface 122 can simply be placed against each other or joined by rivets or the like without a weld or adhesive layer.

[0128] Alternatively, like the third embodiment of the present invention shown in Figures 8 and 9, in the vehicle front side member 10 according to the fourth embodiment of the present invention, the first groove surface 112 of the outer bead 110 and the second groove surface 122 of the inner bead 120 may be spaced apart from each other.

[0129] In the vehicle front side member 10 according to the fourth embodiment of the present invention, first, an outer bead 110 of the outer wall 11 and an inner bead 120 of the inner wall 12 are formed, thereby improving the rigidity of the vehicle body or the front side member in the longitudinal direction X, thereby increasing the amount of load that can be absorbed.

[0130] Furthermore, the vehicle front side member 10 according to the fourth embodiment of the present invention is capable of transmitting collision loads to the rear of the vehicle body not only in a full frontal collision of the vehicle but also in a small overlap collision due to its inclined arrangement, thereby improving the collision performance of the vehicle body.

[0131] For example, in the case of electric vehicles, the weight of the vehicle increases due to the installation of batteries, and the space in the body is reduced, but there is an advantage in that the collision performance and safety can be ensured, which may lead to improved marketability of the vehicle.

[0132] Furthermore, the vehicle front side member 10 of the fourth embodiment of the present invention improves the ease of assembly of the front side member to the vehicle body by connecting the outer rear 15 to the outer wall 11 and the inner rear 16 to the inner wall 12, and can reliably transmit collision loads to at least the front cross member 20, thereby strengthening the support rigidity and maximizing the ability to absorb collision energy during a frontal collision of the vehicle.

[0133] Therefore, the vehicle front side member 10 according to the fourth embodiment of the present invention can ensure excellent collision performance, and since steel material can be used, cost savings can be achieved in terms of materials and construction methods, and a lightweight and structurally strong front side member can be provided.

[0134] FIG. 16 is a cross-sectional view showing a vehicle front side member according to a fifth embodiment of the present invention, and is a drawing of a portion corresponding to FIG.

[0135] The fifth embodiment of the present invention shown in FIG. 16 differs only in that the outer rear 15 is omitted, and the other components are the same as those of the fourth embodiment described above.

[0136] Here, the outer rear 15 may be completely removed or may be molded, for example, continuous with and integral with the side outer panel 13, extending linearly following the side outer panel.

[0137] FIG. 17 is a cross-sectional view showing a vehicle front side member according to a sixth embodiment of the present invention, and shows a portion corresponding to FIG.

[0138] The sixth embodiment of the present invention shown in FIG. 17 differs only in that the inner rear 16 is omitted, and the other components are the same as those of the fourth embodiment described above.

[0139] Here, the inner rear 16 may be completely eliminated or may be molded, for example, continuous with and integral with the side inner panel 14, extending linearly following the side inner panel.

[0140] 18 and 19 are graphs showing deformation forms of a vehicle front side member according to the present invention and a related art vehicle front side member according to the present invention during a full frontal collision.

[0141] FIG. 18 shows the cross-sectional loads associated with the displacement of a first front side member P1 of the prior art arranged parallel to the longitudinal axis of the vehicle body, a second front side member P2 of the prior art arranged at a predetermined angle to the longitudinal axis of the vehicle body, and the front side member I of the first embodiment of the present invention.

[0142] Here, the first and second front side members P1 and P2 of the prior art and the front side member I of the present invention were all equipped with the same bumper beam, and an analysis was performed under full frontal collision conditions.

[0143] In addition, the front side members P1, P2, and I were all formed by welding together a side outer panel and a side inner panel made of 980DP steel.

[0144] The first and second front side members P1 and P2 of the prior art have side outer and inner panels with a thickness of 1.6 mm and weigh approximately 4.8 kg. The front side member I of the present invention has side outer and inner panels with a thickness of 1.2 mm and weighs approximately 4.7 kg.

[0145] The second front side member P2 of the prior art and the front side member I of the present invention are arranged at an inclination angle of 6.3 degrees relative to the longitudinal axis of the vehicle body, and in the front side member I of the present invention, the second angle b between the first inclined surface 113 of the outer bead 110 and the third inclined surface 123 of the inner bead 120 is 2 degrees.

[0146] Referring to FIG. 18, it can be seen that the load received vertically on the cross section at the beginning of the collision is slightly greater on the first front side member P1 of the conventional technology, but the load received vertically on the cross section during overall deformation is much greater on the front side member I of the present invention.

[0147] The first and second front side members P1, P2 of the prior art have a maximum cross-sectional load of 470KN, whereas the front side member I of the present invention has a maximum cross-sectional load of 520KN.

[0148] Furthermore, the front side member I of the present invention stops its overall behavior at a displacement of approximately 380 mm, which indicates that it absorbs even greater collision energy within a shorter displacement than the first and second front side members P1 and P2 of the prior art, whose overall behavior stops when the displacement exceeds 110 mm.

[0149] FIG. 19 shows the energy absorption capacity as a function of time of a first front side member P1 of the prior art arranged parallel to the longitudinal axis of the vehicle body, a second front side member P2 of the prior art arranged at a predetermined angle to the longitudinal axis of the vehicle body, and a front side member I according to the first embodiment of the present invention.

[0150] 19, the total deformation energy in the final state is at a similar level, but the increase in deformation energy is the largest in the front side member I of the present invention. Furthermore, in the 0.04 to 0.06 second interval, the deformation energy of the front side member I of the present invention appears to be higher than that of the first and second front side members P1 and P2 of the prior art, clearly indicating that the energy absorption capacity through deformation of the front side member I of the present invention has a comparative advantage.

[0151] 20 and 21 are graphs showing deformation forms of a vehicle front side member according to the present invention and a conventional technology, which are analyzed during a small overlap collision.

[0152] Figure 20 shows the load in the Y direction (vehicle width direction) as a function of time for a first front side member P1 of the prior art arranged parallel to the longitudinal axis of the vehicle body, a second front side member P2 of the prior art arranged at a predetermined angle relative to the longitudinal axis of the vehicle body, and a front side member I of the first embodiment of the present invention.

[0153] Here, the analysis was performed under small overlap collision conditions with the first and second front side members P1 and P2 of the prior art and the front side member I of the present invention all equipped with the same bumper beam. In addition, the analysis conditions for the structure of the front side members are the same as those for the full frontal collision conditions described above.

[0154] In a small overlap collision, if a vehicle traveling at 64km / h is blocked by an obstacle and its speed instantly drops to 0km / h and it rotates, the passengers' behavior can become unstable. In contrast, if a slide-away behavior occurs in which the vehicle moves a small distance in the Y direction and slides at the initial stage of a small overlap collision, the passengers' behavior can become more stable and the possibility of injury can be reduced.

[0155] To realize such a slide-away behavior, the paths through which the collision energy is transmitted in the vehicle body must have a certain level of strength and rigidity, and each path must be firmly connected.

[0156] 20, since the first front side member of the prior art does not come into direct contact with the obstacle, the increase in the load in the Y direction at the beginning of the collision appears later than the other front side members. As a result, the first front side member of the prior art is disadvantageous to the slide-away behavior, and there is a high possibility that the vehicle will yawing.

[0157] Figure 21 shows the displacement of the mass point in the Y direction (vehicle width direction) over time for a first front side member P1 of the prior art arranged parallel to the longitudinal axis of the vehicle body, a second front side member P2 of the prior art arranged at a predetermined angle relative to the longitudinal axis of the vehicle body, and a front side member I of the first embodiment of the present invention.

[0158] Referring to FIG. 21, it can be seen that the second front side member P2 of the prior art, which is arranged at a predetermined angle relative to the longitudinal axis of the vehicle body, and the front side member I of the present invention, are able to move the vehicle further in the Y direction during a small overlap collision than the first front side member P1 of the prior art, which is arranged parallel to the longitudinal axis of the vehicle body.

[0159] Therefore, according to the present invention, the deformation behavior of the front side member in a full frontal collision is excellent, and the collision energy can be effectively absorbed.

[0160] In addition, the present invention can maximize the vehicle's widthwise behavior in a small overlap collision, improving the collision performance of the vehicle body and safely protecting passengers.

[0161] Furthermore, according to the present invention, it is possible to provide a lightweight and structurally strong front side member, which can ensure excellent collision performance and can achieve cost savings in terms of materials and construction methods because steel materials can be used.

[0162] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations may be made by a person having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

[0163] For example, the embodiments described and illustrated above in the present invention can be combined with each other, and each embodiment can further selectively adopt some components of other embodiments as necessary.

[0164] In this specification, a side member provided at the front of the vehicle body is used as an example for explanation, however, this is not necessarily limited to this, and the technical concept of the present invention can of course also be applied to a side member provided at the rear of the vehicle body.

[0165] Therefore, the embodiments disclosed in the present invention are for the purpose of illustrating, rather than limiting, the technical idea of ​​the present invention, and such embodiments do not limit the scope of the technical idea of ​​the present invention. The scope of protection of the present invention should be interpreted according to the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Industrial Applicability]

[0166] In this manner, the present invention is useful for vehicles, for example, where rigidity of the vehicle body is required.

Claims

1. A front side member for a vehicle, An outer wall; an inner wall positioned opposite the outer wall; an outer bead formed on the outer wall along the longitudinal direction of the vehicle body and having a first groove surface; an inner bead formed on the inner wall along the longitudinal direction of the vehicle body and having a second groove surface; Including, the outer bead includes a region in which a first bead depth, which is a distance between the outer wall and the first groove surface, varies along a longitudinal direction of the vehicle body; the inner bead includes a region in which a second bead depth, which is a distance between the inner wall and the second groove surface, varies along a longitudinal direction of the vehicle body; the outer wall and the inner wall are inclined at a first angle relative to a longitudinal axis of the vehicle body; The first groove surface includes a first inclined surface that connects between groove walls of the outer bead and is inclined at a second angle with respect to an axis in the longitudinal direction of the vehicle body, the second groove surface includes a third inclined surface that connects between groove walls of the inner bead and is inclined at the second angle with respect to an axis in a longitudinal direction of the vehicle body, The second angle is smaller than the first angle.

2. The first groove surface includes a second inclined surface disposed at a third angle with respect to an axis in a longitudinal direction of the vehicle body, The vehicle front side member according to claim 1 , wherein the third angle is greater than the first angle.

3. The first groove surface further includes a first connecting surface that connects the first inclined surface and the second inclined surface, The first connecting surface extends parallel to the outer wall along the length of the vehicle body within the outer bead, 3. The front side member for a vehicle according to claim 2, wherein the first bead depth of the outer bead is changed from a point where the first connecting surface and the first sloping surface connect.

4. The second groove surface includes a fourth inclined surface disposed at a fourth angle with respect to an axis in a longitudinal direction of the vehicle body, The vehicle front side member according to claim 1 , wherein the fourth angle is greater than the first angle.

5. The second groove surface further includes a second connecting surface connecting the third inclined surface and the fourth inclined surface, The second connecting surface extends parallel to the inner wall along the length direction of the vehicle body within the inner bead, 5. The vehicle front side member according to claim 4, wherein the second bead depth of the inner bead is changed from a point where the second connecting surface and the third angled surface connect.

6. 2. The front side member for a vehicle according to claim 1, wherein at one side end of the front side member, the outer wall does not have the outer bead formed, and the inner wall does not have the inner bead formed.

7. the first bead depth of the outer bead gradually becomes deeper toward the other end of the front side member, 7. The vehicle front side member according to claim 6, wherein the second bead depth of the inner bead gradually becomes shallower from the third inclined surface toward the other side end portion.

8. 8. The front side member for a vehicle according to claim 7, wherein the second bead depth and the first bead depth are equal to each other or the second bead depth is deeper than the first bead depth at a midpoint between the one side end and the other side end of the front side member.

9. 2. The vehicle front side member according to claim 1, wherein the first inclined surface of the outer bead and the third inclined surface of the inner bead are in contact with each other.

10. 2 . The vehicle front side member according to claim 1 , wherein the first inclined surface of the outer bead and the third inclined surface of the inner bead are spaced apart from each other by a constant interval.

11. The outer wall is provided on a side outer panel, The inner wall is provided on a side inner panel, 2. The vehicle front side member according to claim 1, wherein the side inner panel is joined to one side of the side outer panel to form a tubular member having a closed cross section.

12. The side outer panel further includes an outer rear having one side connected to an end of the side outer panel so as to branch and extend in a direction different from an extension direction of the side outer panel, The vehicle front side member according to claim 11, wherein the other side end of the outer rear is connected to a side seal or a front cross member of the vehicle body.

13. The front side member for a vehicle according to claim 12, wherein an auxiliary bead is formed on the one side of the outer rear in a shape corresponding to a part of the outer bead.

14. 13. The vehicle front side member according to claim 12, wherein the outer rear has a strength higher than that of the outer wall or is formed to be thicker than the thickness of the outer wall.

15. The side inner panel further includes an inner rear having one side connected to the end of the side inner panel, The vehicle front side member according to claim 11, wherein the other side end of the inner rear is connected to a front cross member or a dash panel of the vehicle body.

16. 16. The vehicle front side member according to claim 15, wherein the inner rear has a strength higher than that of the inner wall or is formed to be thicker than the thickness of the inner wall.

17. 16. The vehicle front side member according to claim 15, wherein the third inclined surface of the second groove surface extends from one side end to the other side end of the inner wall.

18. 18. The front side member for a vehicle according to claim 17, wherein at one side end of the front side member, the outer wall is not formed with the outer bead, and the second bead depth of the inner bead is deepest.

19. the first bead depth of the outer bead gradually becomes deeper toward the other end of the front side member, 19. The vehicle front side member according to claim 18, wherein the second bead depth of the inner bead becomes gradually shallower toward the other end portion.

20. 20. The front side member for a vehicle according to claim 19, wherein the second bead depth and the first bead depth are equal to each other or the second bead depth is deeper than the first bead depth at a midpoint between the one side end and the other side end of the front side member.

21. 21. The vehicle front side member according to claim 1, wherein the front side member is disposed inclined at the first angle relative to a longitudinal axis of the vehicle body.

22. The front side members are disposed on both the left and right sides in a width direction of the vehicle body, The vehicle front side member according to claim 21, wherein the two front side members are disposed so as to approach each other toward the rear of the vehicle body.

23. the first bead depth of the outer bead gradually becomes deeper toward the front of the vehicle body, 23. The vehicle front side member according to claim 22, wherein the second bead depth of the inner bead gradually becomes shallower from the third inclined surface toward the front of the vehicle body.

24. 21. The vehicle front side member of claim 1, wherein the outer wall further includes a reinforcement mounted across the outer bead.

Images