Member, structure, and automobile

Abstract

This member is a hollow tubular member in which a closed cross section is formed by: a top plate part; a first member having a side wall part that is formed continuously to the top plate part through the ridge of the top plate part; and a second member provided at a position opposite to the top plate part of the first member. In an intersection section of the member, a reinforcement member is disposed at a position that is continuous from at least one of a first-direction edge and a corner ridge to at least one of another first-direction edge, a second-direction edge, and another corner ridge that are not in contact with each other, or the reinforcement member is disposed at least on a portion of a first ridge.

Description

Components, structures and automobiles

[0001] This application claims priority from Japanese Patent Application No. 2024-122585, filed on July 29, 2024, the contents of which are incorporated herein by reference.

[0002] Cars have CO ２ While there is a demand for reduced emissions, collision safety regulations are becoming stricter. Therefore, automotive components are required to be lightweight, which contributes to reducing the overall weight of the vehicle, and to have properties that contribute to improving the collision safety of the vehicle, such as crashworthiness.

[0003] Regarding improvements in the collision safety of automobiles, there have been conventional vehicles that have an energy absorbing section on the front straight section of the rail section of the front structure of the vehicle, or on the rear straight section of the rail section of the rear structure of the vehicle, which deforms due to the load input through the bumper in the event of a collision from the front or rear, and absorbs collision energy (for example, Patent Document 1).

[0004] The rail portion in the front or rear structure of a vehicle generally has a closed cross-section structure, and the rear rail of Patent Document 1 has a rear straight section, a front straight section whose tube axis position is different from that of the rear straight section, and a bent section located between the rear straight section and the front straight section. Patent Document 1 discloses a technology that can appropriately absorb collision energy in a rear collision by making the product of the material strength and plate thickness at the bent section greater than the product of the material strength and plate thickness of the rear straight section.

[0005] On the other hand, as mentioned above, automobiles have CO ２To address this need, automotive components are expected to contribute to improving automobile crashworthiness and reducing vehicle weight. In response to this demand, research has been conducted in recent years into integrating multiple components into a single molded piece to significantly reduce the number of components and the number of processes and labor required. As part of this effort, the integration of rear structures has been considered. Here, integrating multiple components into a single molded piece refers to molding multiple components into a single blank, which is a process that previously involved separate molding and subsequent joining. Compared to the conventional method of preparing blanks (materials) for each component, molding them separately, and then joining them, integrating multiple components into a single molded piece can significantly reduce the number of components and the number of processes and labor required. However, in the case of hollow components with a top panel and sidewalls typically used in rear structures, when integrating multiple components (e.g., side members and cross members) extending in intersecting directions, the resulting product inevitably has a large cutout in the sidewall of one component at the intersection (where the component is fastened) with the other component. With such a structure, if a large load is input during a collision, the notched portion may be significantly deformed, and there is a concern that the desired deformation mode may not occur.

[0006] Patent Document 1 does not take into consideration the problems that arise when integrating such multiple members.

[0007] Japan Special Table No. 2022-547492

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a component, as well as a structure and an automobile including the component, that have excellent collision resistance characteristics, even when the side wall of the intersection portion is cut out, such as when multiple components extending in intersecting directions are molded together.

[0009] The inventors have investigated methods for achieving sufficient crashworthiness even when a sidewall of one component is significantly cut out at the intersection (connection) between the components, as occurs when multiple components extending in intersecting directions are integrally molded. As a result, they have found that crashworthiness can be improved by appropriately positioning a reinforcing member at the intersection (connection) between the components. They also found that weight can be reduced by limiting the area where the reinforcing member is positioned (reinforcement area) to the most effective area of ​​the intersection.

[0010] The present invention has been made in light of the above findings. The gist of the present invention is as follows. [1] A member according to one aspect of the present invention is a hollow tubular member having a closed cross section formed by a first member having a top plate portion and a side wall portion formed continuously with the top plate portion via a ridge line, and a second member provided at a position facing the top plate portion of the first member, wherein the member has: a first portion whose tube axis direction is a first direction; and a second portion whose tube axis direction is a second direction intersecting the first direction, one end of the second portion is connected to the first portion at a position spaced from the end of the first portion so that a hollow portion of the first portion communicates with a hollow portion of the second portion, and the ridge lines of the first member, when viewed in plan, include: a first ridge line extending in the first direction; a second ridge line extending in the second direction; and a corner ridge line having a curvature and both ends connected to the first ridge line and the second ridge line, a connecting portion between the corner portion ridgeline and the first ridgeline is defined as a first end, a connecting portion between the corner portion ridgeline and the second ridgeline is defined as a second end, a straight line connecting the first end to the opposing first ridgeline across the top plate portion by the shortest distance is defined as a first direction end, and a straight line connecting the second toes across the top plate portion is defined as a second direction end, and when, in a plan view, a range surrounded by the corner portion ridgeline, the first direction end, the first ridgeline sandwiched between the first direction end, and the second direction end is defined as an intersection, at the intersection, a reinforcing member is arranged in a position continuing from one or more of the first direction end and the corner portion ridgeline to another one or more of the first direction end, the second direction end, and the corner portion ridgeline that do not contact each other, or the reinforcing member is arranged on at least a part of the first ridgeline. [2] In the member described in [1], the reinforcing member may be disposed at the intersection in a position that continues from one of the corner ridge lines to the other of the corner ridge lines. [3] In the member described in [1], the reinforcing member may be disposed at the intersection in a position that continues from one of the first direction ends to the other of the first direction ends and the second direction end.[4] In the member described in [2], the reinforcing member may be disposed over the entire ridge line of one of the corners at the intersection. [5] In the member described in [2], the reinforcing member may be disposed over the entire ridge lines of both corners at the intersection. [6] In the member described in [3], the reinforcing member may be disposed over the entire ridge lines of both corners at the intersection. [7] In the member described in [5], the reinforcing member may be disposed over the entire area of ​​the intersection surrounded by the corner ridge line, the line connecting the first toes, and the line connecting the second toes. [8] In the member described in [6], the reinforcing member may be disposed over the entire area of ​​the intersection surrounded by the corner ridge line, the line connecting the first toes, and the line connecting the second toes. [9] In the member described in [1], the reinforcing member may be disposed at a position at the intersection that continues from one of the first direction end portions to the other first direction end portion.

[10] In the component according to [9], at least a part of the reinforcing member may be disposed on the first ridge line of the intersection.

[11] In the component according to

[10] , the reinforcing member may further be disposed on the entire first ridge line of the intersection.

[12] The member according to any one of [1] to

[11] , wherein the second member has a top plate portion and a side wall portion formed continuously with the top plate portion via a ridge line, and the ridge line of the second member, when viewed from above, has: a first ridge line extending in the first direction; a second ridge line extending in the second direction; and a corner ridge line having a curvature and connected at both ends to the first ridge line and the second ridge line, In the second member, a connection portion between the corner portion ridgeline and the first ridgeline is defined as a first end, a connection portion between the corner portion ridgeline and the second ridgeline is defined as a second end, a straight line connecting the first end to the opposing first ridgeline across the top plate portion at the shortest distance is defined as a first direction end, a straight line connecting the second toes across the top plate portion is defined as a second direction end, and when viewed in a plan view, an area surrounded by the corner portion ridgeline, the first direction end, the first ridgeline sandwiched between the first direction end, and the second direction end is defined as an intersection, at the intersection of the second member, a reinforcing member may be disposed at a position continuing from one or more of the first direction end and the corner portion ridgeline to another one or more of the first direction end, the second direction end, and the corner portion ridgeline that do not contact each other, or the reinforcing member may be disposed on at least a portion of the first ridgeline.

[13] A structure according to another aspect of the present invention includes the member according to any one of [1] to

[11] .

[14] A vehicle according to another aspect of the present invention comprises the member according to any one of [1] to

[11] .

[15] In the vehicle of

[14] , the angle formed between the first direction of the member and the longitudinal direction of the vehicle may be 30° or less.

[16] A structure according to another aspect of the present invention comprises the member according to

[12] .

[17] A vehicle according to another aspect of the present invention comprises the member according to

[12] .

[18] In the vehicle of

[17] , the angle formed between the first direction of the member and the longitudinal direction of the vehicle may be 30° or less.

[0011] According to the above aspects of the present invention, it is possible to provide a member having excellent crashworthiness, as well as a structure and an automobile including the member. The improved crashworthiness of the member contributes to improving the crash safety of the automobile or the like in which the member is used.

[0012] FIG. 2 is a schematic plan view of a member according to the present embodiment (reinforcing members are not shown). FIG. 3 is a schematic cross-sectional view corresponding to line A-A in FIG. 1, where the second member is a flat closing plate. FIG. 4 is a schematic cross-sectional view corresponding to line A-A in FIG. 1, where the second member is a hat-shaped member. FIG. 5 is a schematic cross-sectional view corresponding to line B-B in FIG. 1, where the second member is a flat closing plate. FIG. 6 is a schematic cross-sectional view corresponding to line B-B in FIG. 1, where the second member is a hat-shaped member. FIG. 7 is a schematic view showing an example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 8 is a schematic view showing another example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 9 is a schematic view showing another example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 10 is a schematic view showing another example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 1 is a schematic diagram showing another example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 1 is a schematic diagram showing another example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 2 is a schematic diagram showing another example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 3 is a schematic diagram showing another example of the arrangement of reinforcing members of a member according to the present embodiment. FIG. 4 is a schematic diagram of an example where a member according to the present embodiment has a first portion connected to a side member and a second portion connected to a cross member. FIG. 5 is a schematic diagram of an example where a member according to the present embodiment is an integrated member where a first portion is a side member and a second portion is a cross member. FIG. 6 is a diagram showing the positions of reinforcing members of a member used in the examples. FIG. 7 is a diagram showing the positions of reinforcing members of a member used in the examples. FIG. 8 is a diagram showing the positions of reinforcing members of a member used in the examples. FIG. 9 is a diagram showing the positions of reinforcing members of a member used in the examples. FIG. 10 is a diagram showing the positions of reinforcing members of a member used in the examples. FIG. 10 is a diagram showing the position of a reinforcing member of a member used in an example.FIG. 10 is a diagram showing the position of a reinforcing member of a member used in an example.

[0013] Below, we will explain a member according to one embodiment of the present invention (member according to this embodiment), a structure according to one embodiment of the present invention (structure according to this embodiment), and a vehicle according to one embodiment of the present invention (vehicle according to this embodiment).

[0014] As shown in Figures 2A, 2B, 3A, and 3B, the member 1 according to this embodiment is a hollow tubular member having a closed cross section formed by a first member 11 and a second member 12. As shown in Figure 1 (a plan view from the first member side), the member has a first portion 101 whose tube axis direction is a first direction 31, a second portion 102 whose tube axis direction is a second direction 32 that intersects with the first direction 31, and an intersection 103 connecting the first and second portions. If the second portion extends only on one side of the first portion (the left side in Figure 1), and the first direction 31 and the second direction 32 are substantially perpendicular (for example, an angle between them is 80 to 100°), the member 1 will have a so-called T-shape. This T-shape is preferable compared to other shapes (e.g., a U-shape) because when a load is input from the tip of the first portion, the first portion is less likely to tilt in a direction perpendicular to the load. 2A and 2B show schematic cross-sectional views taken along line A-A in FIG. 1 , and FIGS. 3A and 3B show schematic cross-sectional views taken along line B-B in FIG. 1 . As shown in FIGS. 2A , 2B , 3A , and 3B , the member 1 according to this embodiment is a hollow tubular member having a closed cross section formed by a first member 11 having a top plate portion 13, a side wall portion 14 formed continuously with the top plate portion 13 via a ridge line (first ridge line 51 or second ridge line 52), and a second member 12 provided at a position facing the top plate portion 13 of the first member 11. The first member 11 may have a flange portion 15 as necessary. That is, the first member 11 may be a so-called hat-shaped member having a top plate portion, a side wall portion, and a flange portion. One end of the second portion 102 is connected to the first portion 101 at a position spaced apart from the end of the first portion 101 so that the hollow portions of the first portion 101 and the second portion 102 are mutually communicated. That is, at the connection portion between the first portion 101 and the second portion 102, part of the side wall portion 14 of the first portion 101 is absent, and an opening is provided. In the first portion 101, except for the opening, the ridge line (first ridge line 51) and the side wall portion 14 are formed in pairs on both sides of the top plate portion 13. In the second portion 102, the ridge line (second ridge line 52) and the side wall portion 14 are formed in pairs on both sides of the top plate portion 13. The side wall portion 14 is formed at a position facing the opening of the first portion 101.

[0015] The second member 12 is not limited as long as it is a member that is disposed in a position facing the top plate portion 13 of the first member 11 and that forms a closed cross section together with the first member 11. For example, as shown in Figures 2A and 3A, the second member 12 may be a flat closing plate, or as shown in Figures 2B and 3B, the second member 12 may be a so-called hat-shaped member that has a side wall portion 14 that is formed continuously with the top plate portion via a ridge line, and a flange portion 15 as needed, similar to the first member 11.

[0016] As shown in FIGS. 2A, 2B, 3A, and 3B, the member 1 according to this embodiment is formed by integrally joining a first member 11 and a second member 12. A member having a top plate portion 13 and a side wall portion 14 can be formed, for example, by processing a steel plate into a predetermined shape to obtain a blank, followed by hot stamping. The member 1 according to this embodiment is a hollow tubular member having a closed cross section formed by joining the first member 11 and the second member 12. The joining method for the first member 11 and the second member 12 is not limited and may be any known method. For example, if the first member 11 and the second member 12 have flange portions 15, the flange portions 15 can be joined together using, for example, resistance spot welding. A structural adhesive can also be used in conjunction with spot welding. While the first member 11 is shown as the upper member and the second member 12 is shown as the lower member in the figures, the second member 12 may also be shown as the upper member and the first member 11 as the lower member. Furthermore, although the member 1 according to this embodiment is a hollow tubular member, other members may be disposed in the hollow portion.

[0017] From the viewpoint of reducing the number of components and the number of processes and man-hours, the first member 11 is preferably a member obtained by integrally molding the first portion 101, the second portion 102, and the intersection 103. Regarding the integrally molded range, the first portion 101 preferably has a length of 50 mm or more, and more preferably a length of 100 mm or more, from one end and / or the other end of the intersection 103 in the direction along the first direction. Furthermore, the second portion 102 preferably has a length of 10 mm or more, and more preferably a length of 30 mm or more, in the direction along the second direction. Whether the first member 11 is a member obtained by integral molding can be determined, for example, by the absence of spot weld marks (excluding spot weld marks for joining the first member and the reinforcing member 21 and spot weld marks for joining the first member 11 and the second member 12) at the connection portion between the first portion 101 and the intersection 103 and the connection portion between the second portion 102 and the intersection 103, or the absence of overlapping portions at each connection portion. Alternatively, if wrinkles or defects are present during molding, they can be judged by their continuity.

[0018] The hot stamping method is a method in which a steel sheet to be used as a blank is heated, and the heated blank is formed using a forming die and rapidly cooled using the die to process the blank into a desired strength and shape. The heating temperature of the blank should be the Ac3 point or higher. The Ac3 point is the temperature at which ferrite disappears in the metal structure of the blank. The metal structure after processing by the hot stamping method becomes a structure mainly composed of martensite.

[0019] The first member 11 and the second member 12 may also be members formed by hot stamping a so-called tailored blank. A tailored blank is a member formed by integrating multiple types of steel plates having different tensile strengths and / or thicknesses (including cases where the tensile strengths are the same but the thicknesses are different, the thicknesses are the same but the tensile strengths are different, or both the tensile strength and the thickness are different) by welding. The first member 11 and the second member 12 formed from such a tailored blank have partially different tensile strengths or thicknesses.

[0020] When forming a tailored blank by hot stamping, heating the tailored blank to the Ac point or higher makes it possible to eliminate the heat-affected zone of the weld that remained when the tailored blank was manufactured.

[0021] In the member 1 according to this embodiment, it is preferable that the height of the top plate portion 13 of the first portion 101 of the first member 11 and the height of the top plate portion 13 of the second portion 102 do not differ greatly at the connection portion. For example, it is preferable that the difference in height between the top plate portion 13 of the first portion 101 and the top plate portion 13 of the second portion 102 is equal to or less than the height of the first ridge line 51, more preferably equal to or less than the thickness of the top plate portion 13 of the first portion 101, and even more preferably that the height of the top plate portion 13 of the first portion 101 and the top plate portion 13 of the second portion 102 are approximately the same. When a collision load is applied, the small difference in height between the top plate portion 13 of the first portion 101 and the top plate portion 13 of the second portion 102 makes it less likely that bending will occur at the connection position between the first portion 101 and the second portion 102. When the second member 12 is a hat-shaped member, it is preferable that the height of the top plate portion 13 of the first part 101 and the height of the top plate portion 13 of the second part 102 in the second member 12 also do not differ significantly at the connection portion.

[0022] Furthermore, in the member 1 according to this embodiment, when the first member 11 is viewed in a plane, as shown in FIG. 1 , the first member 11 has a first ridge line 51 extending in a first direction 31, a second ridge line 52 extending in a second direction 32, and a corner ridge line 53 having a curvature and having both ends connected to the first ridge line 51 and the second ridge line 52, respectively. In the member 1 according to this embodiment, when viewed in a plane, the connection between the corner ridge line 53 and the first ridge line 51 is defined as the first end 61, the connection between the corner ridge line 53 and the second ridge line 52 is defined as the second end 62, the straight line connecting the first end 61 with the opposing first ridge line 51 across the top plate portion 13 at the shortest distance is defined as the first direction end 41, and the straight line connecting the second toes 62 across the top plate portion 13 is defined as the second direction end 42. The area enclosed by the corner ridge line 53, the first direction end 41, the first ridge line 51 between the first direction end 41, and the second direction end 42 (the area enclosed by the dotted line in FIG. 1 ) is defined as the intersection 103. When a ridgeline has a curvature in cross section, it has a certain width in plan view, as shown in FIG. 1 and other figures. However, the corner ridgeline 53, first end 61, and second end 62 used to define the intersection 103 are defined as positions on each ridgeline that are far from the tube axis (positions that are on the outer side (edge) of the component in plan view). Similarly, when the straight line connecting the first end 61 to the opposing first ridgeline 51 across the top plate 13 by the shortest distance is defined as the first direction end 41, the end of the straight line is defined as a position on the first ridgeline 51 that is far from the tube axis (positions that are on the outer side (edge) of the component in plan view). In other words, the intersection 103 is the area surrounded by dotted lines in FIGS. 1 and 4A to 11. A portion of the corner ridgeline 53 constitutes a portion of the first direction end 41 and a portion of the second direction end 42. Furthermore, the first direction end 41 includes the first end 61, and the second direction end 42 includes the second end 62.

[0023] A major feature of the component 1 according to this embodiment is that a reinforcing member 21 is disposed at the intersection 103 in the following manner. This reinforcing member 21 improves crashworthiness. In this embodiment, "the reinforcing member 21 is disposed at a predetermined position in a plan view" refers to whether the reinforcing member 21 is fixed at a position that overlaps the predetermined position in a plan view. The reinforcing member does not necessarily have to be disposed at a position (on the outer surface) that is directly observable in a plan view. In other words, the reinforcing member may be disposed on the inner surface of a tubular component. Whether the reinforcing member is disposed at a predetermined position is determined based on the position of each component on which the reinforcing member is disposed (the first component if the reinforcing member is fixed to the first component, or the second component if the reinforcing member is fixed to the second component). In this embodiment, "the reinforcing member 21 is fixed at a position that overlaps the predetermined position in a plan view" refers to the reinforcing member 21 being fixed in direct contact with the first component or the second component at at least one point (preferably multiple points, more preferably substantially the entire surface) of the intersection. For example, even if the reinforcing member 21 is joined to the first or second member only by the flange portion and is positioned so as to overlap a predetermined position in a plan view, if it is spaced apart from the first or second member 11 or 12, it cannot be said that the reinforcing member 21 is fixed in a position overlapping the predetermined position. This is because, if the reinforcing member 21 is spaced apart in this manner, it cannot fully bear the stress applied to the first or second member 11 or 12. As described above, the reinforcing member 21 may be positioned on either the outer or inner surface of the tubular member. However, since the outer surface may interfere with other members, it is preferable to position the reinforcing member on the inner surface. The reinforcing member may be made of, for example, resin fiber or a metal material such as aluminum or steel. However, a steel material such as a steel plate is preferred because of its ease of joining. The tensile strength of the reinforcing member is preferably equal to or greater than the tensile strength of the member to which the reinforcing member is attached.

[0024] There are no particular limitations on the method for attaching (fixing) the reinforcing member 21 to the first member 11. For example, resistance spot welding or laser welding can be applied.

[0025] Furthermore, the timing of attaching the reinforcing member 21 to the first member 11 is not limited. The reinforcing member 21 may be attached to the first member 11 in a blank state, and the blank with the reinforcing member 21 attached may be pressed to obtain the first member 11 with the reinforcing member 21 disposed thereon, or the reinforcing member 21 may be attached after the first member 11 is obtained by pressing.

[0026] The specific arrangement of the reinforcing member 21 will be described.

[0027] In the member 1 according to this embodiment, at the intersection 103, the reinforcing members 21 are arranged at positions that continue from one or more of the first direction end 41 and the corner ridge 53 to another one or more of the first direction end 41, the second direction end 42, and the corner ridge 53 that do not contact one another (however, in the case of the corner ridge 53, the start and end points are the outside of the intersection 103 (the outside (edge) of the member when viewed in plan)), or the reinforcing members 21 are arranged on at least a portion of the first ridge 51. In other words, at the intersection 103, the reinforcing members 21 are arranged so as to continue from one end (outside the intersection 103 of the first direction end 41, the second direction end 42, and the corner ridge 53) to another end. Or the reinforcing members 21 are arranged on at least a portion of the first ridge 51 of the intersection 103. For example, at the intersection 103, as shown in FIG. 4A, the reinforcing member 21 is arranged at a position continuing from one of the first direction ends 41 to the other first direction end 41, or as shown in FIG. 4B, the reinforcing member 21 is arranged at a position continuing from one of the first direction ends 41 to the other first direction end 41 and the second direction end 42, or as shown in FIG. 4C, the reinforcing member 21 is arranged at a position continuing from one corner portion ridge line 53 to the other corner portion ridge line 53, or as shown in FIG. 4D, the reinforcing member 21 is arranged on at least a part of the first ridge line 51 of the intersection 103. Here, the phrase "the reinforcing members 21 are arranged in continuous positions at the intersection 103" means that at least a portion of the reinforcing members 21 is connected (not completely interrupted) from one of the first direction ends 41 to the other first direction end 41, or from one of the first direction ends 41 to the second direction end 42, or from one corner ridge line 53 to the other corner ridge line 53 at the intersection 103. This also includes cases where a hole is formed in part of the reinforcing member 21 or the width of the reinforcing member 21 varies, as shown in Fig. 5. In this case, a sufficient improvement in crash resistance can be achieved with a lighter weight than when the entire intersection 103 is covered.4C is particularly preferable because a reinforcing member is arranged so as to continue from a corner ridge line 53 to another corner ridge line 53, thereby transmitting the load in the order from a first ridge line 51 connected to the corner ridge line 53 to the corner ridge line 53, the reinforcing member 21, the other corner ridge line 53, and the first ridge line 51 connected to this corner ridge line 53. The thickness of the reinforcing member 21 is not limited, but is preferably 1.0 to 3.0 mm. Further examples will be described below.

[0028] In the member 1 according to this embodiment, when the reinforcing member 21 is disposed at a position at the intersection 103 that continues from one of the first direction ends 41 to the other first direction end 41, it is preferable that at least a portion of the reinforcing member 21 be disposed on the first ridge line 51 of the intersection 103 (at a position that overlaps the first ridge line 51), as shown in Fig. 6. Because load is mainly transmitted through the ridge line, disposing the reinforcing member 21 on the first ridge line 51 of the intersection 103 further improves the collision resistance characteristics. It is more preferable that the reinforcing member 21 be disposed over the entire first ridge line 51 of the intersection 103, as shown in Fig. 7. 8 , from the viewpoint of collision resistance, the reinforcing member 21 is more preferably positioned so as to overlap not only the entire first ridge line 51 of the intersection portion 103 but also a portion of the top plate portion 13 of the intersection portion 103, for example, a range of ¼ or more of the length from the first ridge line 51 to the first direction end 41, and even more preferably positioned so as to overlap not only the entire first ridge line 51 of the intersection portion 103 but also a range of ½ or more of the length from the first ridge line 51 to the first direction end 41 of the top plate portion 13 of the intersection portion 103. There is no upper limit to the overlapping range, but the reinforcing member 21 may be positioned so as to overlap not more than ¾ of the length from the first ridge line 51 to the first direction end 41 of the top plate portion 13 of the intersection portion 103.

[0029] Furthermore, in the component 1 according to this embodiment, when the reinforcing member 21 is disposed at a position that continues from one corner ridge line 53 to the other corner ridge line 53 at the intersection 103 (as described above, in the case of the corner ridge line 53, the start and end points are the outside of the intersection (the outside (edge) of the component in a plan view)), as shown in FIG. 9 , the reinforcing member 21 is preferably disposed along the entirety of one corner ridge line 53 at the intersection 103, and more preferably, as shown in FIG. 10 , the reinforcing member 21 is disposed along the entirety of both corner ridge lines 53 at the intersection 103. By disposing the reinforcing member 21 along the entirety of at least one corner ridge line 53, the corner ridge line 53, where stress tends to concentrate, can be reinforced, thereby further improving the crashworthiness. However, if the amount of reinforcing member is reduced to suppress weight increase, the reinforcing member 21 may be disposed along the entirety of the corner ridge line 53 opposite the load input side, but not along the entirety of the other corner ridge line 53.

[0030] Furthermore, in the member 1 according to this embodiment, when the reinforcing member 21 is arranged at the intersection 103 in a position that continues from one of the first direction ends 41 to the other first direction end 41 and the second direction end 42, it is preferable that the reinforcing member 21 be arranged along the entirety of both corner ridge lines 53. As described above, stress tends to concentrate on the corner ridge line 53, so by arranging the reinforcing member 21 on the corner ridge line 53, the collision resistance characteristics are further improved. In this case, the reinforcing member is arranged in a position that continues from one corner ridge line 53 to the other corner ridge line 53.

[0031] 11 , it is more preferable that the reinforcing member 21 is disposed over the entire area enclosed by the corner ridge line 53, the straight line connecting the first toes 61, and the straight line connecting the second toes 62 at the intersection 103. In this case, rigidity is increased and deformation of the intersection is suppressed, thereby further improving crash resistance. Here, the corner ridge line 53, first toes 61, and second toes 62 are considered to be located away from the tube axis of the corner ridge line (at a position away from the tube axis in plan view), as explained in the definition of the intersection 103, when the corner ridge line 53 has a certain width in plan view. Furthermore, when the corner portion ridge line 53 has a certain width in plan view, when the intersection point between the first direction end portion 41 and a position of the corner portion ridge line 53 close to the tube axis, which is adjacent to the above-mentioned range, is defined as 61', as shown in Figure 11, in addition to the above-mentioned range, reinforcing member 21 may also be arranged in a range surrounded by a line connecting 61' and a line connecting the first direction end portions 41, 41 and the first ends 61.

[0032] In the component 1 according to this embodiment, the reinforcing member 21 may be arranged in a combination of the above arrangements. Furthermore, in terms of the effect of improving crash resistance, the reinforcing member 21 may be arranged over the entire intersection 103. However, if the reinforcing member 21 covers the entire surface of the intersection 103, the effect of improving crash resistance can be obtained, but the weight increases significantly. Therefore, it is preferable that the reinforcing member 21 does not cover the entire surface of the intersection 103 in the pattern described above.

[0033] Furthermore, in the member 1 according to this embodiment, the reinforcing member 21 is disposed at least at the intersection 103 as described above. However, the reinforcing member 21 may be disposed throughout the first portion 101 and / or the second portion 102 other than the intersection 103. In this case, the crashworthiness is further improved. The range of the reinforcing member 21 disposed other than at the intersection 103 is not limited. For example, the reinforcing member 21 may be disposed in a range of 10 mm to 100 mm from the second direction end 42 of the second portion 102 in a direction away from the intersection 103 (e.g., 10 mm, 50 mm, or 100 mm (in other words, a range of 0 to 10 mm, 0 to 50 mm, or 0 to 100 mm, with the second direction end being the 0 mm position)). Alternatively, the reinforcing member 21 may be disposed in a range of 10 to 100 mm from the first direction end 41 of the first portion 101 in a direction away from the intersection 103. However, if the range of the reinforcing member 21 is wide, the weight of the member increases. Since placing reinforcing members 21 in areas other than the intersection 103 tends to be less effective than placing reinforcing members 21 at the intersection 103, in order to reduce weight, the placement of reinforcing members 21 in areas other than the intersection 103 may be kept to a minimum, or reinforcing members 21 may be placed only at the intersection 103.

[0034] Furthermore, in the component 1 according to this embodiment, the reinforcing member 21 is disposed at a position overlapping at least the intersection 103 in a plan view. However, the reinforcing member 21 may also be disposed on the side wall 14 (fixed to the side wall). In this case, the crashworthiness is further improved. The extent of the side wall is not limited. For example, the reinforcing member 21 may be disposed in a range from the ridgeline to a position 1 / 10 to 1 / 2 of the height of the side wall 14 (in other words, with the boundary between the ridgeline and the side wall at 0 mm, in a range from 0 mm to 1 / 10 of the height of the side wall, a range from 0 mm to 1 / 4 of the height of the side wall, or a range from 0 mm to 1 / 2 of the height of the side wall). The reinforcing member 21 disposed on the side wall 14 is preferably disposed extending from the reinforcing member 21 disposed at the intersection 103 (connected to the reinforcing member 21 disposed at the intersection 103). However, if the range of the reinforcing member 21 is wide, the weight of the component increases. Since the placement of reinforcing member 21 on side wall 14 tends to be less effective than the placement of reinforcing member 21 on top plate 13 or ridges, the placement of reinforcing member 21 on side wall 14 may be kept to a minimum to reduce weight. Furthermore, a side wall portion is not formed at the connection position (the side wall portion is cut out) so that the hollow portion of first portion 101 and the hollow portion of second portion 102 are connected, but when a reinforcing member is placed at a position continuous from one first direction end to the other first direction end, reinforcing member 21 may be L-shaped, having a surface parallel to top plate 13 and a surface extending in a direction intersecting top plate 13 (e.g., a substantially vertical direction), and the surface of reinforcing member 21 extending in a direction intersecting the top plate portion may be placed in the cut-out portion of the side wall. This also further improves crash resistance. In order to prevent an increase in weight, the surface of the reinforcing member 21 that extends in a direction intersecting with the top plate portion does not need to be disposed in the portion where the side wall portion is cut out.

[0035] Furthermore, in the member 1 according to this embodiment, in addition to the first member 11, the reinforcing member 21 may also be arranged in the second member 12. When the reinforcing member 21 is arranged in the second member 12, similarly to the first member 11, it is preferable that the reinforcing member 21 is arranged at a position that continues from one or more of the first direction end 41 and the corner portion ridge line 53 at the intersection 103 to another one or more of the first direction end 41, the second direction end 42, and the corner portion ridge line 53 that do not contact each other, or that the reinforcing member 21 is arranged on at least a part of the first ridge line 51. For example, in the second member 12, similarly to the first member 11, it is preferable that the reinforcing member 21 is arranged at the intersection 103 at a position continuous from one of the first direction ends 41 to the other first direction end 41, or at a position continuous from one of the first direction ends 41 to the other first direction end 41 and the second direction end 42, or at a position continuous from one corner ridge line 53 to the other corner ridge line 53, or at at least a part of the first ridge line 51 of the intersection 103. Furthermore, in the second member 12, similarly to the first member, the reinforcing member 21 may also be arranged in a range other than the intersection 103, for example, in a range other than the intersection 103 of the top plate portion 13 and / or in the side wall portion 14.

[0036] The member 1 according to this embodiment can be applied as a part of a vehicle structure such as an automobile. That is, the structure according to this embodiment includes the member according to this embodiment. For example, in the member according to this embodiment, as shown in FIG. 12A , by connecting a side member 201 to the first portion 101 and a cross member 202 to the second portion 102, the structure according to this embodiment can be obtained by using the member as a connection between the side member 201 and the cross member 202. Furthermore, as shown in FIG. 12B , the structure according to this embodiment may be such that the first portion 101 of the member according to this embodiment is part of the side member 201 and the second portion 102 is part of the cross member 202. That is, the structure may include a member in which the side member, the cross member, and the connecting portion are integrally molded. Using an integrally molded member is preferable because it reduces the number of parts and the number of processes and man-hours. When applied as a part of a vehicle structure such as an automobile, the thickness of the intersection of the first member and the second member of the member according to this embodiment is preferably 0.8 to 2.3 mm, and the tensile strength of each intersection is preferably 1500 MPa or more. The tensile strength of the intersection portion 103 may be higher than that of the first portion 101 and the second portion 102 (including when they are integrated with the side member or cross member).

[0037] The automobile according to this embodiment includes the above-described member according to this embodiment, or the structural body according to this embodiment including the above-described member according to this embodiment. Below, an example will be described in which the member 1 according to this embodiment included in the automobile according to this embodiment is an integrated member (sometimes referred to as the structural body according to this embodiment) in which the first portion 101 is a side member 201 and the second portion 102 is a cross member 202.

[0038] As shown in FIG. 12B , the structure according to this embodiment includes, for example, a side member 201, which is a first portion 101 arranged along the longitudinal direction of the vehicle, and a cross member 202, which is a second portion 102 arranged along the lateral (width) direction of the vehicle and connecting the pair of side members 201. This intersection 103 corresponds to the intersection 103 of the member according to this embodiment shown in any of FIGS. 1 and 4A to 11 . The structure shown in FIG. 12B may also include a bumper beam 203 joined to one end of the pair of side members 201, as indicated by the dashed-dotted line. As can be seen from the arrangement of the bumper beam 203, in the structure shown in FIG. 12B , the bumper beam 203 side of the pair of side members 201 is the side where a collision is anticipated (the load input side). That is, in this case, the automobile according to this embodiment has this structure arranged in the rear of the vehicle. However, the arrangement position is not limited to the rear of the vehicle, and it can also be arranged in the front of the vehicle. Furthermore, when the load input direction is taken into consideration, the angle between the first direction of the component according to this embodiment and the vehicle longitudinal direction of the automobile according to this embodiment is preferably within 30°, more preferably within 10°, and even more preferably approximately parallel. When the bumper beam 203 is provided, the bumper beam 203 becomes linear during a collision, which makes it easier for the load to be input to the ridgeline on the outside of the first portion (the outside of the vehicle width direction in the structure according to this embodiment). Therefore, in such cases, reinforcing the first ridgeline (the ridgeline on the outside of the first portion of the intersection 103) is particularly effective.

[0039] 12B , the first portion 101 (side member 201) of the member according to this embodiment included in the structure according to this embodiment may include a curved portion 204. Including the curved portion 204 is preferable because it can avoid interference with other members, such as wheel wells that house the front or rear wheels of the vehicle, the engine, the battery, the axles, etc. However, when a bumper beam 203 is attached to the first portion 101, it is preferable not to include a curved portion on the bumper beam 203 side relative to the connection portion (intersection portion) between the side member 201 and the cross member 202.

[0040] In a structure including the member according to this embodiment, when external stress is input due to a collision, the connection portion (intersection) between the side member 201 and the cross member 202 is reinforced, so that the side member 201 on the bumper beam 203 side is preferentially deformed rather than the intersection portion 103, thereby absorbing the collision energy.

[0041] The end of the side member 201 opposite to the bumper beam 203 side can be joined to other structures that make up the cabin of the vehicle.

[0042] Furthermore, in the structure according to this embodiment, the thickness, yield strength, or tensile strength of the region of the side member 201 closer to the bumper beam 203 than the intersection 103 may be smaller than that of the intersection 103. This allows the region closer to the bumper beam 203 to be deformed with higher priority than the intersection 103 when a collision load is input.

[0043] A model was created for FEM analysis. The model was shaped to simulate the structure of an automobile vehicle, measuring 1100 mm in the transverse (width) direction of the vehicle and 1800 mm in the longitudinal direction of the vehicle. The model also had a first portion serving as a side member and a second portion serving as a cross member, as shown in FIG. 12B . The model had reinforcing members arranged at the T-shaped intersection in various patterns, as shown in FIGS. 13A to 13L (patterns without reinforcing members were also created for comparison). The layout of each pattern was as follows: In FIGS. 13A to 13L , the area surrounded by dashed lines (----) represents the intersection. Pattern 1: As shown in FIG. 13A , reinforcing members are arranged at a position that includes the entire intersection. Pattern 2: As shown in FIG. 13B , reinforcing members are arranged at the intersection in positions that continue from the first-direction end to the second-direction end, and also at a portion of the first ridge of the intersection. Pattern 3: As shown in FIG. 13C , the reinforcing member is arranged at the intersection in a position that continues from one of the first direction ends to the other first direction end and second direction end, and the reinforcing member is arranged along the entire first ridge line of the intersection. Pattern 4: As shown in FIG. 13D , the reinforcing member is arranged at the intersection in a position that continues from the first direction end to the second direction end. Pattern 5: As shown in FIG. 13E , the reinforcing member is arranged at the intersection in a position that continues from one of the first direction ends to the other first direction end, and is arranged along the entire first ridge line of the intersection. Pattern 6: As shown in FIG. 13F , the reinforcing member is arranged at the intersection in a position that continues from one of the first direction ends to the other first direction end and second direction end, and is arranged along the entire area enclosed by the corner ridge line of the intersection, the straight line connecting the first toes, and the straight line connecting the second toes. Pattern 7: As shown in FIG. 13G , the reinforcing member is arranged at the intersection in a position that continues from one of the first direction ends to the other first direction end. Pattern 8: As shown in FIG. 13H, the reinforcing members are positioned at the intersections in a continuous position from one corner ridge to the other.Pattern 9: As shown in Figure 13I, the reinforcing member is arranged at the intersection in a position that continues from one of the first direction ends to the other first direction end, and is arranged on a part of the first ridge line of the intersection. Pattern 10: As shown in Figure 13J, the reinforcing member is arranged at a position that continues from one corner ridge line to the other corner ridge line, and is arranged along the entirety of both corner ridge lines of the intersection. Pattern 11: As shown in Figure 13K, the reinforcing member is arranged at the intersection in a position that continues from one corner ridge line to the other corner ridge line, and is arranged along the entirety of one of the corner ridge lines of the intersection. Pattern 12: As shown in Figure 13L, the reinforcing member is arranged at the intersection in a position that continues from one corner ridge line to the other corner ridge line, and is arranged along the entirety of one of the corner ridge lines of the intersection.

[0044] In this component, as shown in Figures 2B and 3B, both the first and second members were hat-shaped components obtained by hot stamping steel sheets, and the first and second members were joined at the flanges to form a hollow component. The first portion was a tailored blank, and the portion closer to the bumper beam (hereinafter referred to as the tip portion) and the second portion were made of steel with a tensile strength of 1000 MPa and a thickness of 1.0 mm, while the remaining portions of the first portion were made of steel with a tensile strength of 2000 MPa and a thickness of 1.4 mm. The reinforcing member was made of steel plate with a thickness of 1.4 mm and a tensile strength of 2000 MPa. This reinforcing member was spot-welded to the inner surface of the hollow component at the same position on the first and second members (so that the positions of the reinforcing members on the first and second members match when viewed from above).

[0045] FEM analysis was performed on these models with different reinforcing member placements under the following conditions. The energy absorption amounts at the tip and intersection were calculated. Conditions: The FMVSS301R rear offset collision was assumed, and a moving deformable barrier (MDB) model was collided from the bumper beam side. The side member was completely restrained at a position 1,150 mm from the end of the bumper beam, opposite the bumper beam across the intersection. The impact speed of the MDB was 80 km / h. The weight of the MDB was 1,360 kgf. The overlap between the evaluation object and the MDB was 70% of the vehicle.

[0046] As a result of the analysis, the effect of the reinforcing member was evaluated based on the ratio (EA1 / EA2) of the energy absorption amount at the tip (EA1) to the energy absorption amount at the intersection (EA2). Specifically, the following criteria were used: ◎: EA1 / EA2 is 30 or more; ○: EA1 / EA2 is 12 to less than 30; △: EA1 / EA2 is 8 to less than 12; ×: EA1 / EA2 is less than 8.

[0047] The weight increase was also evaluated according to the following criteria: △: Weight increase of more than 3.0% ○: Weight increase of more than 2.0% but not more than 3.0% ⊚: Weight increase of not more than 2.0% The results are shown in Table 1.

[0048]

[0049] As can be seen from Table 1, in Nos. 1 to 12, a reinforcing member is disposed at a position that continues from one or more of the first-direction end and corner ridgeline at the intersection to one or more of the other first-direction end, second-direction end, and corner ridgeline that do not contact each other, or a reinforcing member is disposed on at least a portion of the first ridgeline at the intersection. Since the connecting portion (intersection) between the side member and the cross member is a reinforced member, the bumper beam side of the side member deforms preferentially over the intersection, resulting in a greater amount of collision energy absorption (the reinforcing member functions more effectively), and therefore it can be said that the crashworthiness characteristics are improved. In particular, in Nos. 1 and 6, a reinforcing member is disposed at a position that continues from one corner ridgeline to the other corner ridgeline at the intersection, and is disposed along one or both of the entire corner ridgelines, and is disposed along the entire area enclosed by the straight line connecting the corner ridgelines and the first toes at the intersection and the straight line connecting the second toes at the intersection. In Nos. 1, 3, and 4, a reinforcing member is disposed along at least a portion of the first ridgeline at the intersection. The effect was particularly significant when, as in No. 5, the reinforcing member was disposed at a position at the intersection that continued from one first direction end to another first direction end, and the reinforcing member was disposed along the entire first ridge line of the intersection. This is presumably because the load is transmitted primarily through the ridge line, and the reinforcing member was disposed so as to cover the ridge line, which produced a significant effect. On the other hand, considering the need to suppress weight increase, No. 2 and Nos. 4 to 12 are preferable. That is, in No. 5 and No. 6, the effect of the reinforcing member was significant while suppressing weight increase.

[0050] According to the present invention, it is possible to provide a member having excellent crashworthiness, and a structure and an automobile including the member. The improved crashworthiness of the member contributes to improving the crash safety of the automobile and the like in which the member and the structure including the member are used.

[0051] Member 1 First member 11 Second member 12 Top plate portion 13 Side wall portion 14 Flange portion 15 Reinforcement member 21 First portion 101 Second portion 102 Intersecting portion 103 First direction 31 Second direction 32 First direction end 41 Second direction end 42 First ridge line 51 Second ridge line 52 Corner portion ridge line 53 First end 61 Second end 62 Side member 201 Cross member 202 Bumper beam 203 Curved portion 204

Claims

1. A hollow tubular member having a closed cross section formed by a first member having a top plate portion and a side wall portion formed continuously with the top plate portion via a ridge line, and a second member provided at a position facing the top plate portion of the first member, wherein the member has: a first portion whose axial direction is a first direction; and a second portion whose axial direction is a second direction intersecting the first direction; one end of the second portion is connected to the first portion at a position spaced from the end of the first portion so that the hollow portion of the first portion communicates with the hollow portion of the second portion; and the ridge lines of the first member, when viewed in plan, have: a first ridge line extending in the first direction; a second ridge line extending in the second direction; and a corner ridge line having a curvature and connected at both ends to the first ridge line and the second ridge line, wherein the connection portion of the corner ridge line and the first ridge line is a first end and the connection portion of the corner ridge line and the second ridge line is a second end. a first direction end is a straight line connecting the first toes at the shortest distance to the first ridge line that faces the top plate portion, and a second direction end is a straight line connecting the second toes with the top plate portion in between; and when viewed in a plane, an area surrounded by the corner portion ridge line, the first direction end, the first ridge line sandwiched between the first direction end and the second direction end is an intersection, at the intersection, a reinforcing member is arranged in a position that continues from one or more of the first direction end and the corner portion ridge line to another one or more of the first direction end, the second direction end, and the corner portion ridge line that do not contact each other, or the reinforcing member is arranged on at least a part of the first ridge line.

2. The component according to claim 1, wherein the reinforcing member is disposed at the intersection in a continuous position from one of the corner ridge lines to the other of the corner ridge lines.

3. The member according to claim 1, characterized in that the reinforcing member is arranged at a position at the intersection that continues from one of the first direction ends to the other first direction end and the second direction end.

4. The member according to claim 2, characterized in that said reinforcing member is disposed over the entire edge of one of said corners of said intersection.

5. The member of claim 2, wherein said reinforcing member is disposed along the entirety of said corner ridges at both of said intersections.

6. The member of claim 3, wherein said reinforcing member is disposed along the entirety of said corner ridges at both of said intersections.

7. A component according to claim 5, characterized in that the reinforcing member is arranged over the entire area of ​​the intersection surrounded by the corner ridge line, the straight line connecting the first toes, and the straight line connecting the second toes.

8. The component according to claim 6, characterized in that the reinforcing member is arranged over the entire area of ​​the intersection surrounded by the corner ridge line, the straight line connecting the first toes, and the straight line connecting the second toes.

9. The member according to claim 1, characterized in that the reinforcing member is disposed at the intersection at a position continuous from one of the first direction ends to the other of the first direction ends.

10. The member according to claim 9, characterized in that at least a portion of said reinforcing member is disposed on said first ridge line of said intersection.

11. The member according to claim 10, characterized in that the reinforcing member is further disposed over the entire first ridge of the intersection.

12. The second member has a top plate portion and a side wall portion formed continuously with the top plate portion via a ridge line, and when viewed in a plane, the ridge lines of the second member have: a first ridge line extending in the first direction; a second ridge line extending in the second direction; and a corner portion ridge line having a curvature and connected at both ends to the first ridge line and the second ridge line, wherein a first end is a connection portion of the second member between the corner portion ridge line and the first ridge line, a second end is a connection portion of the second member between the corner portion ridge line and the second ridge line, a first direction end is a line connecting the first end to the opposing first ridge line across the top plate portion by the shortest distance, and a second direction end is a line connecting the second toes across the top plate portion, and when viewed in a plane, the area enclosed by the corner portion ridge line, the first direction end, the first ridge line sandwiched between the first direction end, and the second direction end is an intersection portion. The member according to any one of claims 1 to 11, characterized in that at the intersection of the second member, a reinforcing member is arranged in a position that continues from one or more of the first direction end and the corner portion ridge line to another one or more of the first direction end, the second direction end, and the corner portion ridge line that do not contact each other, or the reinforcing member is arranged on at least a part of the first ridge line.

13. A structure comprising a component according to any one of claims 1 to 11.

14. A motor vehicle, characterized in that it comprises a component according to any one of claims 1 to 11.

15. The automobile according to claim 14, wherein the angle formed between the first direction of the member and the longitudinal direction of the vehicle is within 30°.

16. A structure comprising a member according to claim 12.

17. A motor vehicle comprising the component according to claim 12.

18. The automobile according to claim 17, wherein the angle formed between the first direction of the member and the longitudinal direction of the vehicle is within 30°.

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