construction element

Abstract

The present disclosure aims to provide a structural member with a good balance between bending strength and lightness. In the present disclosure, the above problem is solved by providing a structural member having an end portion T1 and an end portion T2 opposite to the end portion T1 in a plan view in the height direction (Z-axis direction), the structural member having, in a case where an axis connecting the end portion T1 and the end portion T2 is set as an X-axis direction, a region A including the end portion T1 and a region B located at a position closer to the end portion T2 than the region A and including the end portion T2, the region A having a closed cross-sectional portion A with an outer edge shape being one closed cross section A in a cross section perpendicular to the X-axis direction, and the region B having a closed cross-sectional portion B satisfying predetermined (i) or (ii).

Description

Technical Field

[0001] This disclosure relates to a structural component. Background Technology

[0002] For example, the lower front arm, a suspension component of a car, is an L-shaped member, and bending strength in the longitudinal direction of the vehicle is necessary (see, for example, Patent Document 1). When the car's tires drive onto a curb or step, a large load acts on the tire in the longitudinal direction (from front to rear). This load is input from the tire via the steering knuckle arm, etc., to the outer end of the lower front arm in the vehicle width direction, and acts as a bending force that causes the outer end to bend towards the inner end. Furthermore, if the bending force is large due to the large load, the outer end will undergo plastic deformation towards the inner end. With such plastic deformation, the tire alignment changes, thereby affecting the car's ride comfort or handling. In addition, if the bending force is even greater, buckling may occur in the lower front arm. If such buckling occurs, the tire alignment will be significantly misaligned, the car will be unable to move, and as a result, it will be impossible to transport the car to a repair shop by itself.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2019-103152 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] To improve the deformation strength of the lower arm, it is necessary to increase the moment of inertia of the lower arm section relative to the aforementioned bending force. Therefore, previous designs have taken the following steps: increasing the width of each part of the lower arm, or giving the ends of the component a predetermined shape.

[0008] On the other hand, given global environmental concerns, reducing CO2 emissions necessitates lightweighting automobiles. To achieve this, the thinning of the lower front arm's walls has been a significant trend in recent years. However, if this thinning results in bending deformation in the lower front arm along the vehicle's longitudinal direction, out-of-plane deformation (deformation along the vehicle's height) can easily occur, distorting the originally designed cross-sectional shape. If the cross-sectional shape is distorted, achieving high bending strength becomes difficult. This same problem is not limited to automotive components but also exists in structural components used in other structures such as moving bodies or buildings.

[0009] This disclosure was made in view of the above-mentioned actual situation, and its main purpose is to provide a structural member with a good balance between bending strength and lightweight.

[0010] Solution for solving the problem

[0011] [1] A structural component, wherein,

[0012] When viewed from above in the height direction, i.e., the Z-axis direction, the aforementioned structural member has an end T1 and an end T2 opposite to the aforementioned end T1.

[0013] When the axial direction connecting the aforementioned end T1 and the aforementioned end T2 is set as the X-axis direction, the aforementioned structural member has, along the aforementioned X-axis direction: region A, which includes the aforementioned end T1; and region B, which is located closer to the aforementioned end T2 than region A, and also includes the aforementioned end T2.

[0014] The aforementioned region A, in a cross-section perpendicular to the aforementioned X-axis direction, has an outer edge shape that is a closed cross-section A, which is a closed cross-section portion A.

[0015] The aforementioned region B has a closed cross-section B that satisfies either (i) or (ii) below.

[0016] (i) The closed section portion B has a closed section B1 and a closed section B2 in a section perpendicular to the X-axis direction. The closed section B1 and the closed section B2 are connected via the bottom forming the recess and are arranged separately from each other.

[0017] (ii) The closed section portion B has an open section B1 and an open section B2 formed by the recess in a section perpendicular to the X-axis direction. The depth of the recess in the Z-axis direction of the closed section B is more than 50% of the maximum length of the closed section B in the Z-axis direction.

[0018] [2] According to the structural component described in [1], wherein,

[0019] The closed section portion B described above satisfies (i) above.

[0020] [3] According to the structural component described in [1], wherein,

[0021] The closed section portion B described above satisfies (ii) above.

[0022] [4] The structural member according to any one of [1] to [3], wherein,

[0023] Along the +X direction from the aforementioned end T1 toward the aforementioned end T2, the shape of the closed section portion in the cross section perpendicular to the aforementioned X-axis direction of the aforementioned structural member is formed in a manner that continuously changes from the aforementioned closed section portion A to the aforementioned closed section portion B.

[0024] [5] The structural member according to any one of [1] to [4], wherein,

[0025] When viewed from above in the aforementioned height direction, i.e., the Z-axis direction, and taking the axis orthogonal to the aforementioned X-axis direction as the Y-axis direction, and taking the length of the aforementioned structural member in the aforementioned Y-axis direction as L, SY In the case where the above-mentioned structural member has the above-mentioned L SY The bending shape increases along the +X direction from the aforementioned end T1 toward the aforementioned end T2.

[0026] The closed section B1 is arranged along the inner edge of the curved shape, and the closed section B2 is arranged along the outer edge of the curved shape.

[0027] [6] The structural member according to any one of [1] to [5], wherein,

[0028] When viewed from above in the aforementioned height direction, i.e., the Z-axis direction, the axis orthogonal to the aforementioned X-axis direction is designated as the Y-axis direction, and any axis parallel to the aforementioned X-axis direction and passing through the aforementioned end T2 is designated as the X1 axis. The length of the aforementioned region A along the aforementioned X1 axis is designated as L. AX Any point P on the aforementioned region A along the X1 axis. A Let the length of region A in the Y-axis direction be L. AY In this situation, L AX / L AY At at least one of the above points P A The value must be between 1.0 and 4.0.

[0029] [7] The structural member according to any one of [1] to [6], wherein,

[0030] The aforementioned closed section B is constructed using a single component.

[0031] [8] The structural member according to any one of [1] to [6], wherein,

[0032] The aforementioned closed section B is constructed using two or more components.

[0033] [9] The structural member according to any one of [1] to [8], wherein,

[0034] The aforementioned structural components are structural components of a car.

[0035]

[10] The structural member according to any one of [1] to [9], wherein,

[0036] The aforementioned structural component is the lower forearm.

[0037]

[11] The structural member according to any one of [1] to

[10] , wherein,

[0038] As the material for forming the above-mentioned structural components, at least steel plates are used, and the tensile strength of the steel plates is 780 MPa or higher.

[0039] The effects of the invention

[0040] The structural components disclosed herein achieve a good balance between bending strength and lightweight. Attached Figure Description

[0041] Figure 1 This is a schematic top view illustrating the structural components in this disclosure.

[0042] Figure 2 This is a schematic top view illustrating the structural components in this disclosure.

[0043] Figure 3 yes Figure 2 A schematic cross-sectional view of the structural components shown.

[0044] Figure 4 This is a schematic cross-sectional view illustrating the closed section portion B in this disclosure.

[0045] Figure 5 This is a schematic top view illustrating the structural components in this disclosure.

[0046] Figure 6 This is a schematic cross-sectional view illustrating the closed section A in this disclosure.

[0047] Figure 7 This is a schematic cross-sectional view illustrating the closed section A in this disclosure.

[0048] Figure 8 This is a schematic cross-sectional view illustrating the closed section A in this disclosure.

[0049] Figure 9 This is a schematic cross-sectional view illustrating the closed section A in this disclosure.

[0050] Figure 10 This is a schematic cross-sectional view illustrating the closed section A in this disclosure.

[0051] Figure 11 This is a schematic cross-sectional view illustrating the closed section A in this disclosure.

[0052] Figure 12 This is a schematic cross-sectional view illustrating the closed section portion B in this disclosure.

[0053] Figure 13 This is a schematic cross-sectional view illustrating the closed section portion B in this disclosure.

[0054] Figure 14 This is a schematic cross-sectional view illustrating the closed section portion B in this disclosure.

[0055] Figure 15 These are schematic top views and schematic sectional views illustrating the structural components in this disclosure.

[0056] Figure 16 This is a schematic top view illustrating the structural components in this disclosure.

[0057] Figure 17 This is a schematic top view illustrating the structural components in this disclosure.

[0058] Figure 18 These are schematic top views and schematic sectional views of the shape model of the structural component produced in Example 1.

[0059] Figure 19 These are schematic top views and schematic sectional views of the shape model of the structural component made in Reference Example 1.

[0060] Figure 20 These are schematic top views and schematic sectional views of the shape model of the structural component made in Comparative Example 1.

[0061] Figure 21 These are the evaluation results of Examples 1-3, Reference Example 1, and Comparative Example 1. Detailed Implementation

[0062] The structural components of this disclosure are described in detail below. For ease of understanding, the size and shape of the parts are appropriately exaggerated in the following figures. Also, for convenience, section lines or reference numerals are omitted in some figures.

[0063] Figure 1 This is a schematic top view illustrating a structural component of this disclosure, specifically illustrating the forearm. Figure 1 The structural member 10 shown is used to connect the lower part of a steering knuckle (not shown) to the vehicle body, which supports a wheel with a tire for free rotation. End T1 on one end side of the structural member 10 indicates the location of the ball joint mounted on the steering knuckle. Furthermore, end T2, opposite end T1 in the X-axis direction, and end T3, located further to the +Y direction than end T2, indicate the connection points with body components (not shown), such as a subframe. The structural member 10 is fixed to the body component by means of, for example, bushing joints (not shown) provided at end T2 and end T3.

[0064] In addition, such as Figure 1 As shown, structural member 10 is an L-shaped member. Specifically, the length of structural member 10 in the Y-axis direction is set as L. SYIn the case that the structural member 10 has L SY A curved shape that increases along the +X direction. In structural member 10, the side with the larger radius of curvature of the curved shape is sometimes referred to as the outer side of the curve, while the side with the smaller radius of curvature is referred to as the inner side of the curve.

[0065] Figure 2 This is a schematic top view illustrating a structural component in this disclosure. Figure 3 yes Figure 2 The diagram shows a schematic cross-sectional view of the structural components. Specifically, Figure 3 (a) is Figure 2 AA section view, Figure 3 (b) is Figure 2 CC section view, Figure 3 (c) is Figure 2 BB cross-sectional view.

[0066] Figure 2 The structural member 10 shown has an end T1 and an end T2 opposite to end T1. Furthermore, when the axis connecting end T1 and end T2 is set as the X-axis direction, the structural member 10 has, along the X-axis direction: region A, which includes end T1; and region B, which is located closer to end T2 than region A and also includes end T2. Additionally, a region C may exist between region A and region B as an intermediate region between the two.

[0067] like Figure 3 As shown in (a), Figure 2 The region A shown has an outer edge shape that is a closed section A of a closed section A in a cross section perpendicular to the X-axis direction. Figure 3 The closed section A shown in (a) is composed of a top surface portion 1, a bottom surface portion 2, a first wall portion 3, and a second wall portion 4. In this disclosure, "closed section" refers to a shape in which the outer edge is closed within the section (the outer edge is annular, and there are no ends in the circumferential direction of the cross-sectional shape), and "closed section portion" refers to a part having a closed section. Furthermore, in Figure 3 In (a), the bottom part 2 is opposite to the top part 1, the first wall part 3 connects the top part 1 and the bottom part 2, and the second wall part 4 is opposite to the first wall part 3 and connects the top part 1 and the bottom part 2.

[0068] like Figure 3 As shown in (c), Figure 2 The region B shown has a closed section B in a cross-section perpendicular to the X-axis direction. This closed section B has a closed section B1 and a closed section B2, which are connected via a bottom 53 forming the recess 5 and are arranged separately from each other. Figure 3In (c), the closed section B1 is composed of the top surface 1, the bottom surface 2, the first wall portion 3, and the wall portion 51 of the recess 5, while the closed section B2 is composed of the top surface 1, the bottom surface 2, the second wall portion 4, and the wall portion 52 of the recess 5. Alternatively, it can be as follows... Figure 4 As shown, region B has a closed section portion B, which has an open section B1 and an open section B2 divided by the recess 5. That is, an open section B1 can be used instead of a closed section B1, and an open section B2 can be used instead of a closed section B2. In this disclosure, "open section" refers to a shape in which the outer edge is open in the section (the outer edge is end-shaped, with an end present in the circumferential direction of the section shape). Furthermore, the depth d in the Z-axis direction of the recess 5 in the closed section B... B The maximum length h in the Z-axis direction of the closed section B. B It can be more than 50%, or more than 70%, or more than 80%, or more than 90%.

[0069] like Figure 3 As shown in (b), Figure 2 The region C shown has a closed section C, which has a closed section C. The shape of the closed section C changes continuously along the +X direction from the closed section A to the closed sections B1 and B2. Figure 3 The closed section C shown in (b) is composed of a top surface 1, a bottom surface 2, a first wall 3, and a second wall 4, which have recesses 5.

[0070] Here, as Figure 2 As shown, closed section B1 is positioned along the inner edge of the bend in the curved shape, and closed section B2 is positioned along the outer edge of the bend in the curved shape. Therefore, Figure 2 The closed section of the structural member 10 shown branches into closed section B1 and closed section B2 along the +X direction from closed section A. Figure 2 Because the closed section B in the structure is provided with material at a position far from the neutral axis of the bend, the moment of inertia of the section of the structural member 10 can be increased.

[0071] According to this disclosure, the component has closed section A and closed section B as closed sections perpendicular to the X-axis direction, thus becoming a structural member with a good balance between bending strength and lightweight. Here, if a load in the +Y direction is input to the component mounted on... Figure 2The center of the component (e.g., a ball joint) at end T1 is subjected to a bending force that shifts the center position towards end T3, resulting in a compressive load on the first wall portion 3. The closed section portion in this disclosure functions as a load-bearing portion that suppresses out-of-plane deformation of the first wall portion 3 due to this compressive load. In particular, by placing the closed section portion B, which has good bending strength, in the region B, which is more affected by the compressive load, it is possible to suppress the shape collapse of the closed section portion B. Furthermore, while the closed section portion B has better bending strength than the closed section portion A, it is less lightweight. Therefore, by placing the closed section portion A in the region A, which is relatively unaffected by the compressive load, lightweight can be improved. This results in a structural member with a good balance between bending strength and lightweight.

[0072] 1. Area A

[0073] like Figure 5 As shown, region A in this disclosure is the region including end T1. In addition, region A has a closed section A at the boundary with other regions adjacent to region A (e.g., region B, region C, or region D).

[0074] like Figure 5 As shown, any axis parallel to the X-axis and passing through end T2 is designated as the X1 axis, and the length of region A on the X1 axis is designated as L. AX Any point P on region A along the X1 axis A Let the length of region A in the Y-axis direction be L. AY The X1 axis can also be the axis passing through the branch points explained later. Additionally, any point P... A It could also be the intersection of the X1 axis and the end point T1. L AX Compared to L AY The proportion (L) AX / L AY At at least any point P A The value must satisfy, for example, 0.5 or higher, or 1.0 or higher, or 1.5 or higher. If L AX / L AY If it's too small, there's a possibility that the lightweight improvement effect brought by region A will be reduced. On the other hand, L... AX / L AY At at least any point P A For example, it can satisfy a value below 4.0, or it can satisfy a value below 3.5, or it can satisfy a value below 3.0. If L AX / L AY If the value is too large, there is a possibility that the effect of increasing bending strength brought about by region B will be reduced.

[0075] In addition, such as Figure 5 As shown, let the length on the X1 axis of region A be L.AX Let the length of region B on the X1 axis be L. BX Let the length of region C on the X1 axis be L. CX L AX Compared to L BX and L CX The total (L) TX The proportion of (L) AX / L TX () can be, for example, 0.10 or higher, or 0.30 or higher. If L AX / L TX If it's too small, there's a possibility that the lightweight improvement effect brought by region A will be reduced. On the other hand, L... AX / L TX For example, it could be below 1.87, or below 0.95. If L... AX / L TX If the area is too large, there is a possibility that the improvement in bending strength brought about by region B will be reduced. In addition, the distance on the X1 axis from end T1 to end T2 is, for example, more than 300 mm and less than 600 mm.

[0076] Region A has a closed section A in a cross-section perpendicular to the X-axis direction, the outer edge of which is a closed section A. That is, the closed section A has only one closed section A as a closed section defined from its outer edge. Furthermore, the closed section is defined by the shape of its outer edge as described above. Therefore, even if the closed section is internally divided into multiple regions due to the presence of partition walls or the like inside the closed section, the closed section is still considered as a single closed section. On the other hand, for example, as explained later... Figure 19 The structural member 10 shown has a closed section portion with two closed cross sections on the end T1 side. Such a closed section portion does not conform to the closed section portion A in this disclosure. In addition, the closed section A is a closed section without a predetermined recess. "Predetermined recess" refers to a recess in the closed section A whose depth in the Z-axis direction is more than 50% of the maximum length of the closed section A in the Z-axis direction.

[0077] The shape of the outer edge of the closed section A is not particularly limited; for example, polygons such as rectangles, circles, and ellipses can be included. Furthermore, the polygons in this disclosure include not only strictly polygonal shapes but also shapes in which the corners of a polygon are formed into arcs. Figure 6 The closed section A shown is composed of a top portion 1, a bottom portion 2, a first wall portion 3, and a second wall portion 4. Furthermore, although in Figure 6The sides of the closed section are represented by straight lines, but the sides of the closed section in this disclosure are not limited to straight lines and may also be curves. Region A preferably has a plurality of regions in the X-axis direction in which closed section portions A are formed, but closed section portions A may also be present in the entire region in the X-axis direction.

[0078] The closed section A can be constructed using a single component. Such a component is obtained, for example, by stamping a sheet of metal and then performing a fixing process to form the closed section. Examples of fixing processes include methods of fixing the metal sheets together. More specific examples of fixing processes include spot welding, laser welding, arc welding, riveting, crimping, bolting, and other mechanical joints, as well as bonding with adhesives. The fixing process forms the fixed section.

[0079] Alternatively, the closed section A can be constructed using two or more components. For example, two or more metal sheets can be stamped together, joined together, and then fixed to form the closed section, thereby obtaining such a structural component. The fixing process is the same as described above.

[0080] Figure 7 The closed section A shown in (a) to (d) is a closed section constructed using a single component. Figure 7 In the closed section A shown in (a), a fixing part is formed on the top part 1. Figure 7 In the closed section A shown in (b), a fixing part is formed on the bottom part 2. Figure 7 In the closed section A shown in (c), a fixing part is formed in the first wall part 3. Figure 7 In the closed section A shown in (d), a fixing part is formed in the second wall portion 4. Furthermore, although in Figure 7 In (a) to (d), a fixing part is formed over the entire area of ​​the top surface, bottom surface, first wall portion, or second wall portion, but it is sufficient if a fixing part is formed at least partially. Furthermore, as will be explained later... Figures 8-11 In the middle, a fixing part is formed in the part where the components are arranged in an overlapping manner; the description of the fixing part is omitted.

[0081] Figure 8 The closed section A shown in (a) to (f) is a closed section composed of two components. Figure 8 In (a) to (f), the fixing part is a joining method in which two components are joined on the outer edge line. Additionally, in Figure 8In (a) to (f), S1 to S4 correspond to any one of the top surface, bottom surface, first wall portion, and second wall portion, respectively. For example, if S1 is the top surface, S3 corresponds to the bottom surface, and one of S2 and S4 corresponds to the first wall portion and the other corresponds to the second wall portion. Furthermore, in Figure 8 In (a) to (f), for convenience, S1 and S3 are shown as longer than S2 and S4, but S1 and S3 can also be shorter than S2 and S4, or they can be the same as S2 and S4. S1 to S4 will be explained later. Figures 9-11 The same applies to China. Figure 8 In the closed section A shown in (a) to (d), the components constituting S1 and S2, S3, and S4 are used. This can be achieved as follows: Figure 8 As shown in (a) and (c), the components constituting S1 are arranged and joined in such a way that they cover the components constituting S2, S3, and S4, or they can be joined as shown in (c). Figure 8 As shown in (b) and (d), the components constituting S2, S3, and S4 are joined together in a manner that covers the component constituting S1. Figure 8 In (a) and (c), there are two fixing parts for fixing the component constituting S1 and the components constituting S2, S3, and S4 together. In both fixing parts, the component constituting S1 is positioned further outward than the components constituting S2, S3, and S4. On the other hand, in Figure 8 In (b) and (d), there are two fixing parts for fixing the component constituting S1 and the components constituting S2, S3, and S4 together. In both fixing parts, the component constituting S1 is positioned more inwardly than the components constituting S2, S3, and S4. Furthermore, it can be as follows... Figure 8 As shown in (a) and (b), a fixing part is formed in S2 and S4, or it can be as follows: Figure 8 As shown in (c) and (d), a fixing part is formed in S1. Additionally, in Figure 8 In the closed section A shown in (e), the components constituting S1 and S4, as well as the components constituting S2 and S3, are used. Figure 8 In (e), in the fixing part on the S2 side, the components constituting S1 and S4 are positioned further outward than the components constituting S2 and S3; in the fixing part on the S4 side, the components constituting S1 and S4 are positioned further inward than the components constituting S2 and S3, which is inconsistent. Thus, when multiple fixing parts exist, the components positioned inward and outward can be either consistent or inconsistent. Figure 8 In the closed section A shown in (f), the components constituting S1, S2, and S4, and the components constituting S2, S3, and S4, are formed using two components each. Alternatively, as shown... Figure 8As shown in (f), the fixing part is formed not by stacking the components but by butting the components together (joining the end faces of the components with each other).

[0082] Figure 9 The closed section A shown in (a) to (e) is also similar to Figure 8 Similarly, (a) through (f) are all closed cross-sections constructed using two components. Figure 9 In (a) to (e), the fixing part is a joint method in which at least one of the two components has a flange. Figure 9 In the closed section A shown in (a), the components constituting S1 and S4, as well as the components constituting S2 and S3, are used, with S2 and S4 each having a flange. Figure 9 In the closed section A shown in (b), the components constituting S1, S2, and S4, and the component constituting S3 are used, with S2 and S4 each having a flange. Figure 9 In the closed section A shown in (c), the components constituting S1 and S2, S3, and S4 are used, and S1 has two flanges. Figure 9 In the closed section A shown in (d), components constituting S1, S2, and S4, and components constituting S2, S3, and S4 are used, with S2 and S4 each having a flange. Figure 9 In the closed section A shown in (e), the components constituting S1 and S4 and the components constituting S2 and S3 are used, and S2 and S3 each have a flange. Figure 9 As shown in (a) to (e), the location for forming the flange is not particularly limited. Furthermore, when multiple fixing parts are provided, for example, it is also possible to... Figure 8 The joining method shown and Figure 9 The shown combination of joining methods.

[0083] Figure 10 The closed section A shown in (a) and (b) is a closed section composed of four components. Figure 10 In the closed section A shown in (a) and (b), components constituting S1 to S4 are used respectively. Figure 10 In (a), the components constituting S2 are joined in a manner that covers the components constituting S1 and S4. This joining method is similar to... Figure 8 The joining method of the components constituting S1 in (a) is the same. The joining method of each component is not limited to Figure 8 The joining method in (a) can also be adopted Figure 8 The joining methods in (b) to (f) can also be as follows: Figure 9 The flanges are used for joining, as shown in (a) to (e). Furthermore, the joining methods of the individual components can be the same or different from each other.

[0084] In this disclosure, the members constituting the sides of the closed section A can also have a closed section structure. Specifically, in Figure 11 In the closed section A shown in (a), S2 (e.g., the first wall portion) has a closed section structure. Furthermore, the multiple members constituting the edges of the closed section A may also have a closed section structure. Specifically, in Figure 11 In the closed section A shown in (b), S2 and S4 (e.g., the first wall and the second wall) each have a closed section structure. The interior of the closed section structure can be either hollow or filled with a filler such as resin.

[0085] 2. Region B

[0086] like Figure 5 As shown, region B in this disclosure is a region located and including end T2, which is closer to region A than region A. Specifically, region B is a region located closer to the +X direction than the boundary with other regions adjacent to region B (e.g., region A, region C, or region D). Furthermore, region B has a closed section B at the boundary with other regions adjacent to region B. Additionally, region B has a closed section B that satisfies either (i) or (ii) below.

[0087] The closed section portion B satisfying (i) above has closed sections B1 and B2 in a section perpendicular to the X-axis direction. These closed sections B1 and B2 are connected via the bottom forming the recess and are arranged separately from each other. Furthermore, the closed section portion B satisfying (i) above has closed sections B1 and B2 as closed sections defined from its outer edge. The shapes of the outer edges of closed sections B1 and B2 are not particularly limited; for example, polygons such as rectangles, circles, and ellipses can be listed respectively.

[0088] Figure 12 The closed section portion B shown in (a) has a closed section B1 and a closed section B2. 2， The closed sections B1 and B2 are connected via the bottom 53 forming the recess 5 and are arranged separately from each other. Closed section B1 is composed of a top surface 1, a bottom surface 2, a first wall portion 3, and a wall portion 51 of the recess 5; closed section B2 is composed of a top surface 1, a bottom surface 2, a second wall portion 4, and a wall portion 52 of the recess 5. Furthermore, the length L of the recess 5 in the Y-axis direction... β Preferably along the +X direction ( Figure 12 The distance between closed sections B1 and B2 preferably increases along the +X direction. Specifically, it is preferable that... Figure 2As shown, a closed section B1 is arranged along the inner edge of the bend, and a closed section B2 is arranged along the outer edge of the bend. Closed sections B1 and B2 are increasingly separated by distance along the +X direction. Furthermore, as... Figure 12 As shown in (a), the bottom 53 of the recess 5 can be positioned on the side of the bottom surface 2 (-Z direction) with reference to the top surface 1 in a section perpendicular to the X-axis direction. On the other hand, although not specifically shown, the bottom of the recess can also be positioned on the side of the top surface (+Z direction) with reference to the bottom surface in a section perpendicular to the X-axis direction. Furthermore, in Figure 12 In (a), the bottom 53 of the recess 5 has a portion continuously formed from the wall portion 51 and the wall portion 52. In this bottom 53, the bottom surface portion 2 is discontinuously formed. On the other hand, in Figure 12 In (b), the bottom 53 of the recess 5 has a portion that is continuously formed from the bottom surface 2. In this bottom 53, the portion that is continuously formed from the wall portion 51 is discontinuous with the portion that is continuously formed from the wall portion 52.

[0089] In addition, the length L in the Y-axis direction of the closed section B1 B1Y The length L of the closed section B2 in the Y-axis direction B2Y They can be the same or different. For example, in Figure 13 In (a), L B1Y Compared to L B2Y Large. On the contrary, in Figure 13 In (b), L B2Y Compared to L B1Y big.

[0090] On the other hand, the closed section portion B that satisfies (ii) above has an open section B1 and an open section B2 formed by the concave portion in a section perpendicular to the X-axis direction. For example Figure 14 The closed section portion B shown in (a) has an open section B1 and an open section B2 formed by the recess 5. Additionally, as described above... Figure 4 As shown, the depth d of the recess 5 in the closed section B along the Z-axis is... B The maximum length h in the Z-axis direction of the closed section B. B It can be more than 50%, or more than 70%, or more than 80%, or more than 90%. In the case where the closed section B has open sections B1 and B2, such as... Figure 14 As shown in (a), the bottom 53 of the recess 5 does not contact the bottom surface 2. Alternatively, it can be as follows: Figure 14As shown, the bottom 53 of the recess 5 is positioned on the side of the bottom surface 2 (-Z direction) with reference to the top surface 1 in a section perpendicular to the X-axis direction. On the other hand, although not specifically shown, the bottom of the recess can also be positioned on the side of the top surface (+Z direction) with reference to the bottom surface in a section perpendicular to the X-axis direction. Additionally, the depth d... B It can also be the maximum length h B Approximately 100%. In this case, such as Figure 14 As shown in (b), the bottom 53 of the recess 5 can also contact the bottom surface 2. In this case, the closed section portion B has a closed section B1 and a closed section B2. In addition, when the bottom 53 of the recess 5 contacts the bottom surface 2, a fixing portion for fixing both can also be formed.

[0091] The closed section portion B can be constructed using one component or two or more components. These aspects, except for the recess, are the same as those described in the closed section portion A above.

[0092] 3. Region C

[0093] like Figure 5 As shown, the structural member in this disclosure may also have a region C located between region A and region B in the X-axis direction. Region C is a region in which the shape of the closed section portion in the cross-section of the structural member perpendicular to the aforementioned X-axis direction continuously changes from closed section portion A to closed section portion B along the direction from end T1 to end T2 (+X direction). That is, along the +X direction, the closed section portion of the structural member is formed in such a way that the cross-sectional shape continuously changes from closed section portion A to closed section portion B.

[0094] Region C has a closed section C in a cross-section perpendicular to the X-axis direction, and this closed section C has a closed cross-section C. The closed section C may have only one closed cross-section C as a closed cross-section defined from its outer edge. The shape of the closed cross-section C is not particularly limited, except for the concave portion, and is the same as described regarding the closed cross-section A. Figure 3 The closed section C shown in (b) is composed of a top portion 1, a bottom portion 2, a first wall portion 3, and a second wall portion 4, each with a recess 5. Furthermore, the depth of the recess 5 in the closed section C is set as d. C Region C has a branch point (the branch point of the closed section) located at the boundary between closed section A and closed section C.

[0095] Figure 15 (a) is a schematic top view illustrating a structural component in this disclosure. Figure 15 (b) is Figure 15 (a) of C X -C X Sectional view. CX -C X An axis is an axis parallel to the X-axis and passing through the branch point located at the boundary between closed section A and closed section C. For example... Figure 15 As shown in (a) and (b), the depth d of the recess 5 in region C (closed section C) is... C It increases continuously along the +X direction (from end T1 towards end T2). Figure 15 In (b), the depth d at the boundary between region A and region C C It is 0, depth d C As the +X direction increases, the depth d at the boundary between region B and region C... C With depth d B (The depth of the recess 5 in closed section B) is consistent. The boundary line between region C and region A becomes the line passing through C. X -C X The dividing point on the axis is the aforementioned branch point, and the line is parallel to the Y-axis direction. The dividing line between region C and region B is the line passing through C. X -C X A line that marks the boundary on the axis and is parallel to the Y-axis direction.

[0096] Furthermore, region C has a closed section C along the entire X-axis from its boundary with region A to its boundary with region B. The closed section C can be constructed using one component or two or more components. These aspects, except for the recess, are the same as those described for the closed section A above.

[0097] Furthermore, the structural member in this disclosure may not have region C. In this case, it becomes a structural member that changes discontinuously from closed section A in region A to closed sections B1 and B2 in region B along the direction from end T1 to end T2 (+X direction). The boundary between region A and region B becomes the boundary between closed section portion A and closed section portion B.

[0098] Alternatively, the structural member in this disclosure may have one or more regions (not shown) with open cross-sections or regions (not shown) having closed cross-sections that are discontinuous with closed cross-sections A, B1, and B2, in the direction from end T1 to end T2 (+X direction), instead of region C. That is, region A and region B may be arranged separately, with one or more regions with open cross-sections or regions having closed cross-sections that are discontinuous with closed cross-sections A, B1, and B2 between region A and region B. The entire region replacing region C is designated as region D, which is an open cross-section. That is, region D is located between region A and region B, and the entire region is composed of open cross-sections. Furthermore, in the top view of the structural member, closed cross-section A branches towards closed cross-section B, and region D has a branch point located at the boundary with closed cross-section A. The cross-sectional shape of region D is... Figure 15 (a) of C X -C X In the sectional view, the shape is such that the bottom 2 of region C is not present. The boundary line between region D and region A is a line passing through the aforementioned branch point and parallel to the Y-axis. The axis parallel to the X-axis and passing through the aforementioned branch point is designated as D. X -D X If the depth of the concave portion 5 in region D is set as d... D Then in D X -D X In the sectional view, at the boundary between region D and region B, the depth d D With depth d B Consistent. The boundary between region D and region B becomes the line passing through D. X -D X The line that marks the boundary on the axis and is parallel to the Y-axis direction. The length L of region D on the X1 axis. DX The length L on the X1 axis relative to the structural member 10 X (=L AX +L DX +L BX For example, it could be below 0.2. That is, it could be L. DX / L X ≤0.2.

[0099] 4. Structural components

[0100] The structural members in this disclosure preferably have a curved shape when viewed from above. For example... Figure 16 As shown, this curved shape is a shape in which the length of the structural member 10 in the Y-axis direction increases along the +X direction. That is, this curved shape is defined as the length in the Y-axis direction at the position of the structural member 10 near the end T1 being L. SY1And let L be the length of the Y-axis at the position of the structural member 10 relative to the end T2 side. SY2 In the case of becoming L SY1 <L SY2 The shape. Strictly speaking, the center of curvature of the inner edge α of the curved shape is located outside the structural member 10. The first wall portion 3 may also be arranged along the inner edge α of the curved shape. On the other hand, the second wall portion 4 may also be arranged along the outer edge β of the curved shape.

[0101] The materials constituting the structural components in this disclosure are not particularly limited. Examples include metallic materials such as steel, aluminum alloys, and magnesium alloys, and resin materials containing fibers such as glass fibers and carbon fibers (e.g., CFRP). Alternatively, the structural components may also be composite materials of metallic and resin materials.

[0102] In this disclosure, steel plate is preferably used as the material forming the structural member. The tensile strength of the steel plate or other metal plate is not particularly limited; for example, it can be 780 MPa or more, or 980 MPa or more. Furthermore, the thickness of the steel plate or other metal plate is, for example, 1 mm or more and 3 mm or less.

[0103] The use of the structural components in this disclosure is not particularly limited; for example, automotive applications can be listed. That is, the structural components can be structural components of automobiles. Examples of structural components of automobiles include suspension components such as the front lower arm, rear lower arm, front upper arm, and rear upper arm. Figure 17 This is a schematic top view illustrating a structural component of this disclosure, specifically a schematic top view illustrating the front lower arm. The front lower arm's longitudinal direction (in the vehicle's longitudinal direction) Figure 17 The longest length (in the left-right direction of the paper) is, for example, more than 260mm and less than 460mm. The front lower arm's length in the vehicle width direction ( Figure 17 The longest length (vertical direction on paper) is, for example, 300mm or more and 600mm or less. The front lower arm's length in the vehicle height direction ( Figure 17 The longest length (in the paper depth direction) is, for example, 30 mm or more and 100 mm or less. In addition, the structural components of this disclosure can be used not only in automobiles, but also in mobile bodies such as autonomous two-wheeled vehicles, ships, and aircraft, as well as in building structures.

[0104] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any embodiment having a structure that is substantially the same as the technical concept described in the claims of this disclosure and achieving the same effect is included within the protection scope of this disclosure.

[0105] Example

[0106] [Example 1]

[0107] Create on a computer using CAD (Computer-Aided Design) software. Figure 18 The shape model of the structural component shown. Figure 18 (a) is a schematic top view of the shape model of the structural component made in Example 1. Figure 18 (b) is Figure 18 Sectional view AA of (a), Figure 18 (c) is Figure 18 (a) BB section view.

[0108] Figure 18 The structural member 10 shown in (a) has the aforementioned ends T1, T2, and T3, and also has regions A, B, and C. The midpoint of end T1 in the Y-axis direction is designated as point P1. Furthermore, L... AX / L AY Set it to 1.0. L AX Let L be the length of region A along the X1 axis (not shown) passing through the branch point located at the boundary between closed section A and closed section C. AY Let X1 be the length of region A in the Y-axis direction at the intersection of the X1 axis and end point T1. Additionally, as... Figure 18 As shown in (b), Figure 18 Region A in the structural member 10 shown in (a) has a closed section A, which is a closed section A composed of a top surface portion 1, a bottom surface portion 2, a first wall portion 3, and a second wall portion 4. On the other hand, as Figure 18 As shown in (c), Figure 18 Region B in the structural member 10 shown in (a) has a closed section portion B, which has closed sections B1 and B2 arranged separately from each other.

[0109] [Example 2]

[0110] Besides changing it to L AX / L AY Except for 2.0, the shape model of the structural component is made in the same manner as in Example 1.

[0111] [Example 3]

[0112] Besides changing it to L AX / L AY Except for 3.0, the shape model of the structural component is made in the same way as in Example 1.

[0113] [Reference Example 1]

[0114] Created on a computer using CAD (Computer Aided Design) software. Figure 19 The shape model of the structural component shown. Figure 19 (a) is a schematic top view of the shape model of the structural component made in Reference Example 1. Figure 19 (b) is Figure 19 (a) BB section view. Figure 19 As shown in (a) and (b), except that a closed section B is formed throughout the region along the X-axis, the shape model of the structural member is made in the same manner as in Example 1.

[0115] [Comparative Example 1]

[0116] Created on a computer using CAD (Computer Aided Design) software. Figure 20 The shape model of the structural component shown. Figure 20 (a) is a schematic top view of the shape model of the structural component made in Comparative Example 1. Figure 20 (b) is Figure 20 AA section view of (a).

[0117] like Figure 20 As shown in (a) and (b), the shape model of the structural member is made in the same manner as in Embodiment 1, except that an open cross-section portion having a top surface portion 11 with a recess 15, a first wall portion 13 and a second wall portion 14 is formed to replace the closed cross-section portion A, closed cross-section portion B and closed cross-section portion C in Embodiment 1.

[0118] [evaluate]

[0119] For the shape models of the structural components fabricated in Examples 1-3, Reference Example 1, and Comparative Example 1, CAE (Computer-Aided Engineering) analysis was performed to obtain displacement-load curves and calculate the maximum load [kN] of these curves. The analysis conditions were set to apply a load in the +Y direction to point P1 with ends T2 and T3 fixed. Furthermore, the material properties of the structural components were as follows: 980MPa grade steel plate with a thickness of 2.3mm was used in Examples 1-3 and Reference Example 1, while 780MPa grade steel plate with a thickness of 3.85mm was used in Comparative Example 1. The maximum load [kN] was divided by the component weight [kg] to obtain the maximum load per unit weight. The results are shown in Table 1 and... Figure 21 middle.

[0120] [Table 1]

[0121] Comparative Example 1 14.2 Reference Example 1 16.2 Example 1 17.8 Example 2 17.9 Example 3 16.6

[0122] As shown in Table 1 and Figure 21As shown, it was confirmed that the maximum load per unit weight of Examples 1-3 was higher than that of Comparative Example 1. That is, it was confirmed that the structural members of Examples 1-3 (structural members with predetermined closed cross-sections) had a better balance between bending strength and lightweight compared to the structural member of Comparative Example 1 (structural member with open cross-section).

[0123] Furthermore, it was confirmed that the maximum load per unit weight of Examples 1-3 was higher than that of Reference Example 1. This is because the structural member of Reference Example 1 only has a closed section B, while the structural member of Example 1 has both a closed section B and a lightweight closed section A. Therefore, it is speculated that the structural member of Example 1 achieves a better balance between bending strength and lightweight.

[0124] Explanation of reference numerals in the attached figures

[0125] 1. Top surface; 2. Bottom surface; 3. First wall portion; 4. Second wall portion; 5. Recess; 10. Structural component.

Claims

1. A structural component, wherein, When viewed from above in the height direction, i.e., the Z-axis direction, the structural member has an end T1 and an end T2 opposite to the end T1. When the axis connecting the end T1 and the end T2 is set as the X-axis direction and the axis orthogonal to both the X-axis direction and the Z-axis direction is set as the Y-axis direction, the structural member has an end T3 located on the +Y direction side of the end T2, and the structural member has a region A along the X-axis direction, which includes the end T1. Region B, which is located closer to end T2 than region A, and includes end T2 and end T3. Region A has a closed section A in a cross-section perpendicular to the X-axis direction, with its outer edge being a closed cross-section A. Region B has a closed cross-section B that satisfies either (i) or (ii) below. (i) The closed section portion B has a closed section B1 and a closed section B2 in a section perpendicular to the X-axis direction. The closed section B1 and the closed section B2 are connected via the bottom forming the recess and are disposed separately from each other. The closed section B1 extends from the end T1 side to the end T3 side, and the closed section B2 extends from the end T1 side to the end T2 side. (ii) The closed section portion B has an open section B1 and an open section B2 formed by the recess in a section perpendicular to the X-axis direction. The open section B1 extends from the end T1 side to the end T3 side, and the open section B2 extends from the end T1 side to the end T2 side. The depth of the recess in the Z-axis direction in the closed section B is more than 50% of the maximum length of the closed section B in the Z-axis direction.

2. The structural member according to claim 1, wherein, The closed section portion B satisfies (i).

3. The structural member according to claim 1, wherein, The closed section portion B satisfies (ii).

4. The structural member according to claim 1 or 2, wherein, Along the +X direction from end T1 toward end T2, the shape of the closed section portion in the cross section perpendicular to the X-axis direction of the structural member is formed in a manner that changes continuously from the closed section portion A to the closed section portion B.

5. The structural member according to claim 1 or 2, wherein, When viewed from above in the height direction, i.e., the Z-axis direction, the length of the structural member in the Y-axis direction is set as L. SY In the case that the structural member has the L SY A curved shape that increases in the +X direction from end T1 toward end T2. The closed section B1 is arranged along the inner edge of the bend of the curved shape, and the closed section B2 is arranged along the outer edge of the bend of the curved shape.

6. The structural member according to claim 1 or 2, wherein, When viewed from above in the height direction, i.e., the Z-axis direction, any axis parallel to the X-axis direction and passing through the end T2 is designated as the X1 axis, and the length of region A along the X1 axis is designated as L. AX Any point P on the region A of the X1 axis A Let the length of region A in the Y-axis direction be L. AY In this situation, L AX / L AY At at least one of the points P A The value must be between 1.0 and 4.

0.

7. The structural member according to claim 1 or 2, wherein, The closed section B is constructed using a single component.

8. The structural member according to claim 1 or 2, wherein, The closed section B is constructed using two or more components.

9. The structural member according to claim 1 or 2, wherein, The structural component is a structural component of an automobile.

10. The structural member according to claim 1 or 2, wherein, The structural component is the forearm.

11. The structural member according to claim 1 or 2, wherein, As the material for forming the structural member, at least a steel plate is used, and the tensile strength of the steel plate is 780 MPa or higher.

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