Structure member

Abstract

To provide a structure member for a vehicle body that is able to hinder a change in a cross-sectional shape in the event of collision and is able to reduce an amount of CO2 emission.SOLUTION: A structure member (10) includes a member body (11) and a reinforcing member (12). The member body (11) includes two vertical walls (112, 113), a top plate (111), and two flanges (114, 115). The reinforcing member (12) is joined to the top plate (111) and the vertical wall (112, 113). The reinforcing member (12) includes a first reinforcing layer (121) and a second reinforcing layer (122). The first reinforcing layer (121) is made of resin. The resin has a specific gravity of 0.05 or more and 1.00 or less. The second reinforcing layer (122) is made of a fiber-reinforced resin. The second reinforcing layer (122) is laid over the first reinforcing layer (121). The first reinforcing layer (121) is disposed between the member body (11) and the second reinforcing layer (122) and has a thickness (t1) greater than a thickness (t2) of the second reinforcing layer (122).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to structural members for vehicle bodies. [Background technology]

[0002] For example, in an automobile, the body is formed by a number of structural members. Some of these structural members have different performance requirements depending on the part. For example, some structural members require deformation in order to absorb collision energy in some parts, while other parts require deformation to be prevented. In order to satisfy such requirements, structural members have been partially reinforced in the past.

[0003] To partially reinforce a structural member, for example, a tailored blank (tailor welded blank or tailor rolled blank) is used. A tailored blank is a plate material whose strength and / or plate thickness differs depending on the part. However, because a tailored blank is generally made of steel, it is difficult to significantly reduce the weight of a structural member when using a tailored blank.

[0004] In order to partially reinforce a structural member, a reinforcing material may be attached to a part of the structural member. Patent Document 1 discloses a structural member using a fiber-reinforced resin material as a reinforcing material. In Patent Document 1, the structural member is reinforced by a first fiber-reinforced resin material and a second fiber-reinforced resin material. The first fiber-reinforced resin material has a plurality of randomly oriented fiber bodies, and is arranged at intervals in the thickness direction of the structural member. The second fiber-reinforced resin material has a plurality of fiber bodies oriented in one direction, and is arranged between the structural member and the first fiber-reinforced resin material. The second fiber-reinforced resin material is bonded to the structural member by an adhesive. The thickness of the second fiber-reinforced resin material is smaller than the thickness of the first fiber-reinforced resin material. The fiber bodies included in these fiber-reinforced resin materials are carbon fibers or glass fibers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-162920 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, high-strength materials have come to be used more and more for structural members of vehicle bodies. The use of high-strength materials allows the structural members to be made thinner and thus to reduce their weight. However, high-strength, thin-walled structural members have a problem in that they undergo increased elastic deformation during a collision, making their cross-sectional shape more likely to change. If the cross-sectional shape of the structural member changes significantly during a collision, it is difficult to obtain the effects of high-strength materials. For this reason, it is necessary to efficiently reinforce the necessary parts of the structural member and suppress the change in the cross-sectional shape of the structural member.

[0007] In Patent Document 1, a laminate of first and second fiber-reinforced resin materials is used as a reinforcing material for a structural member. In Patent Document 1, in order to suppress changes in the cross-sectional shape of the structural member, it is necessary to ensure a sufficient thickness of the fiber-reinforced resin material. However, the greater the thickness of the fiber-reinforced resin material, the greater the amount of fibrous material, which is carbon fiber or glass fiber, used. CO 2 Since the amount of emissions is relatively large, if the amount of fiber used in structural components increases, the amount of CO emitted during manufacturing 2 This will result in a significant increase in emissions.

[0008] The present disclosure suppresses changes in cross-sectional shape during a collision and reduces CO 2 The present invention aims to provide a structural member for a vehicle body that can reduce emissions. [Means for solving the problem]

[0009] A structural member for a vehicle body according to the present disclosure includes a member body and a reinforcing material. The member body includes two vertical walls, a top plate, and two flanges. The two vertical walls are arranged to face each other. The top plate connects the two vertical walls. The two flanges are connected to the two vertical walls on the opposite side of the top plate, respectively, and protrude outward from the vertical walls. The reinforcing material is joined to the top plate and the two vertical walls. The reinforcing material includes a first reinforcing layer and a second reinforcing layer. The first reinforcing layer is made of a resin. The resin has a specific gravity of 0.05 or more and 1.00 or less. The second reinforcing layer is made of a fiber-reinforced resin. The second reinforcing layer is laminated on the first reinforcing layer. The first reinforcing layer is arranged between the member body and the second reinforcing layer. The first reinforcing layer has a thickness greater than a thickness of the second reinforcing layer. Effect of the Invention

[0010] According to the vehicle body structural member of the present disclosure, it is possible to suppress the change in cross-sectional shape during a collision, and the CO 2 Emissions can be reduced. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view that illustrates a structural member according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the structural member shown in FIG. 1 taken along line II-II. [Diagram 3] FIG. 3 is a graph showing the mass efficiency and greenhouse gas (GHG) emissions in Example 1 and Comparative Examples 1 to 5. [Figure 4] FIG. 4 is a graph showing the mass efficiency and greenhouse gas (GHG) emissions in Examples 1 to 6 and Comparative Example 5. [Diagram 5] FIG. 5 is a diagram showing the deformation behavior of a structural member having a hat-shaped cross section in a dynamic three-point bending simulation analysis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Fig. 5 is a diagram showing the deformation behavior of a structural member 90 having a hat-shaped cross section in a dynamic three-point bending simulation analysis. Fig. 5 shows only one side of the cross section of the structural member 90 relative to the width center line (dotted line). As shown in Fig. 5, the structural member 90 includes a top plate 91, a vertical wall 92, and a flange 93. Another structural member 80 is joined to the flange 93 of the structural member 90, and the structural members 80, 90 form a closed cross section.

[0013] 5, in a dynamic three-point bending simulation analysis, when an impactor is collided with the top plate 91 and a load is applied, the top plate 91 is depressed inwardly of the structural member 90, while the vertical wall 92 is deformed to bulge outwardly in the width direction of the structural member 90 in the cross section of the structural member 90. When the inventors confirmed, the amount of bulging (amount of displacement) d h increased in proportion to the tensile strength of the structural member 90. In addition, the amount of expansion d h increased inversely proportional to the thickness of the structural member 90.

[0014] The above-mentioned change in the cross-sectional shape of the structural member is caused by elastic deformation. Therefore, the greater the amount of elastic deformation of the structural member, the more likely the cross-sectional shape of the structural member is to change during a vehicle body collision. In addition, the smaller the bending rigidity of the structural member, the more likely the cross-sectional shape is to change. The inventors have studied a configuration for suppressing the change in the cross-sectional shape, and have completed a structural member according to an embodiment.

[0015] A structural member for a vehicle body according to an embodiment includes a member body and a reinforcing material. The member body includes two vertical walls, a top plate, and two flanges. The two vertical walls are arranged to face each other. The top plate connects the two vertical walls. The two flanges are connected to the two vertical walls on the opposite side of the top plate, respectively, and protrude outward from the vertical walls. The reinforcing material is joined to the top plate and the two vertical walls. The reinforcing material includes a first reinforcing layer and a second reinforcing layer. The first reinforcing layer is made of resin. The resin has a specific gravity of 0.05 or more and 1.00 or less. The second reinforcing layer is made of fiber-reinforced resin. The second reinforcing layer is laminated on the first reinforcing layer. The first reinforcing layer is arranged between the member body and the second reinforcing layer. The first reinforcing layer has a thickness greater than a thickness of the second reinforcing layer (first configuration).

[0016] In the structural member according to the first configuration, reinforcing materials are joined to the top plate and two vertical walls of the structural member body. The first reinforcing layer of the reinforcing material on the structural member body side is made of a resin with a relatively large thickness but a low specific gravity. Therefore, the bending rigidity of the structural member can be increased weight-efficiently at the positions of the top plate and each vertical wall without significantly increasing the weight of the structural member. This makes it possible to suppress changes in the cross-sectional shape of the structural member when the vehicle body is hit.

[0017] In the first configuration, a second reinforcing layer is laminated on the first reinforcing layer of the reinforcing material on the opposite side of the member body. The second reinforcing layer is made of a fiber-reinforced resin with a relatively large elastic modulus (Young's modulus). This can further increase the rigidity of the structural member at the positions of the top plate and each vertical wall. Therefore, changes in the cross-sectional shape of the structural member are more easily suppressed in the event of a vehicle body collision.

[0018] In the first configuration, the first reinforcing layer made of resin ensures the thickness of the structural member at the positions of the top plate and each vertical wall. Therefore, there is no need to thicken the second reinforcing layer made of fiber-reinforced resin. Therefore, compared to when the reinforcing material is made of only fiber-reinforced resin, the amount of fiber used can be reduced, and CO2 emissions in the manufacture of the structural member can be reduced. 2 Emissions can be reduced.

[0019] In this way, the structural member according to the first configuration can suppress the change in the cross-sectional shape during a collision, and can reduce the CO 2 Emissions can be reduced.

[0020] In the structural member according to the first configuration, the second reinforcing layer may include a plurality of randomly oriented fibrous bodies (second configuration).

[0021] When a vehicle body crashes, the structural members undergo elastic deformation in various directions. For example, when the structural members undergo bending deformation, the top plate deforms in the width direction as well as the longitudinal direction of the structural member. In contrast, in the second configuration, the second reinforcing layer of the reinforcing material contains a plurality of randomly oriented fibrous bodies. This makes it possible to increase the rigidity of the top plate and each vertical wall against deformation in various directions.

[0022] In the structural member of the first or second configuration, in the cross section of the structural member, the reinforcing material may be positioned within the range on the top plate side relative to the height center of the two vertical walls (third configuration).

[0023] The above-mentioned change in the cross-sectional shape of the structural member occurs due to the action of a longitudinal compressive force caused by bending deformation due to a collision load. The compressive force acts on the top plate side of the center of the height direction of each vertical wall. In the third configuration, the reinforcing material is provided within the range where the compressive force acts. Therefore, the change in the cross-sectional shape of the structural member can be more efficiently suppressed.

[0024] In a structural member relating to any one of the first to third configurations, when the thickness of the first reinforcing layer is t1 and the thickness of the second reinforcing layer is t2, it is preferable that t1 and t2 satisfy 1.3≦t1 / t2≦9.0 (fourth configuration).

[0025] In the structural member according to any one of the first to fourth configurations, the reinforcing member may be joined to the top plate and the two vertical walls by an adhesive (fifth configuration).

[0026] In the structural member according to any one of the first to fifth configurations, the first reinforcing layer is made of, for example, a foamed resin (sixth configuration).

[0027] In a sixth configuration, the first reinforcing layer of the reinforcing material is made of a foamed resin, which makes it possible to further reduce the weight of the reinforcing material and the structural member including the reinforcing material.

[0028] The structural member according to any one of the first to sixth configurations may be a center pillar. In this case, it is preferable that the reinforcing material is provided over 10% or more of the longitudinal length of the member body (seventh configuration).

[0029] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and the same description will not be repeated.

[0030] [Outline of structural components] Fig. 1 is a perspective view showing a structural member 10 according to the present embodiment. Fig. 1 also shows another structural member 20 together with the structural member 10 according to the present embodiment. The structural members 10 and 20 are used in, for example, the body of an automobile or the like.

[0031] 1, a structural member 10 includes a member body 11 and a reinforcing member 12. The member body 11 has an elongated shape. The member body 11 includes a top plate 111, two vertical walls 112, 113, and two flanges 114, 115. The top plate 111, the vertical walls 112, 113, and the flanges 114, 115 extend in the longitudinal direction of the member body 11.

[0032] The vertical walls 112, 113 are disposed to face each other. The vertical walls 112, 113 are connected by a top plate 111. The flange 114 is connected to one of the vertical walls 112 on the opposite side of the top plate 111. The flange 115 is connected to the other vertical wall 113 on the opposite side of the top plate 111. The flanges 114, 115 protrude from the vertical walls 112, 113 to the outside of the member body 11.

[0033] The reinforcing member 12 is joined to the member body 11. The reinforcing member 12 is provided, for example, on a portion of the member body 11 in the longitudinal direction.

[0034] [Detailed configuration of structural members] Fig. 2 is a cross-sectional view taken along line II-II of the structural member 10 shown in Fig. 1. Fig. 2 shows a cross section (transverse section) of the structural member 10 cut by a plane perpendicular to the longitudinal direction of the member body 11 at the position of the reinforcing member 12. The configuration of the structural member 10 will be described in more detail below with reference to Fig. 2.

[0035] (Component body) As shown in FIG. 2, the member body 11 has a cross section formed into a hat shape by a top plate 111, vertical walls 112 and 113, and flanges 114 and 115.

[0036] In the cross section of the member body 11, the vertical wall 112 and the flange 114 are disposed on one side of the top plate 111. The vertical wall 112 includes a vertical wall main body 112a and corner portions 112b and 112c. The vertical wall main body 112a is connected to the top plate 111 via the corner portion 112b. The vertical wall main body 112a is connected to the flange 114 via the corner portion 112c. In the cross section of the member body 11, the vertical wall main body 112a extends from the corner portion 112b on the top plate 111 side to the corner portion 112b on the flange 114 side. In the cross section of the member body 11, the corner portions 112b and 112c can have, for example, an arc shape.

[0037] In the cross section of the member body 11, the vertical wall 113 and the flange 115 are disposed on the other side of the top plate 111. The vertical wall 113 includes a vertical wall main body 113a and corner portions 113b and 113c. The vertical wall main body 113a is connected to the top plate 111 via the corner portion 113b. The vertical wall main body 113a is connected to the flange 115 via the corner portion 113c. In the cross section of the member body 11, the vertical wall main body 113a extends from the corner portion 113b on the top plate 111 side to the corner portion 113c on the flange 115 side. In the cross section of the member body 11, the corner portions 113b and 113c can have, for example, an arc shape.

[0038] In the cross section of the member body 11, the vertical wall 112 and the flange 114 on one side are aligned with the vertical wall 113 and the flange 115 on the other side along a width center line CL w The width center line CL may be symmetric or asymmetric. w is a straight line passing through the midpoint of a line segment connecting the boundary between the top plate 111 and the vertical wall 112 and the boundary between the top plate 111 and the vertical wall 113 in the cross section of the member body 11, and perpendicular to the line segment. The boundary between the top plate 111 and the vertical wall 112 ends at the R on the top plate 111 side of the corner portion 112b. The boundary between the top plate 111 and the vertical wall 113 ends at the R on the top plate 111 side of the corner portion 113b. On the other hand, the boundary between the vertical wall 112 and the flange 114 ends at the R on the flange 114 side of the corner portion 112c. The boundary between the vertical wall 113 and the flange 115 ends at the R on the flange 115 side of the corner portion 113c.

[0039] The top plate 111 may be flat or may have projections and recesses in the cross section of the member body 11. For example, the top plate 111 may be provided with a recess to improve the rigidity of the top plate 111.

[0040] The member body 11 is made of a metal plate. The member body 11 can be formed by press molding of a metal plate. The member body 11 is typically made of a steel plate. However, the member body 11 may be made of a plate material made of aluminum, titanium, magnesium, copper, nickel, or an alloy thereof.

[0041] The plate thickness t of the member body 11 is, for example, 0.8 mm or more. The plate thickness t of the member body 11 is preferably 2.0 mm or less. The tensile strength of the member body 11 is, for example, 980 MPa or more. The tensile strength of the member body 11 is preferably 1180 MPa or more, and more preferably 1500 MPa or more.

[0042] When the structural member 10 is installed in the vehicle body, the opening of the hat-shaped member body 11 is closed by another structural member 20. That is, the member body 11 forms a closed cross section together with the structural member 20. The structural member 20 is joined to the flanges 114, 115 of the member body 11 by, for example, welding.

[0043] The structural member 20 is made of a metal plate. The material of the structural member 20 may be the same as or different from that of the main body 11 of the structural member 10. The plate thickness and tensile strength of the structural member 20 may also be the same as or different from that of the main body 11 of the structural member 10.

[0044] (Reinforcement) In this embodiment, the reinforcing member 12 is disposed inside the member body 11. In a cross-sectional view of the structural member 10, the reinforcing member 12 is provided so as to follow the entire top plate 111 of the member body 11 and at least a part of the vertical walls 112, 113. The reinforcing member 12 extends from the top plate 111, passing over the corner portions 112b, 112c, to reach the vertical wall main bodies 112a, 113a. The reinforcing member 12 is joined to the top plate 111 and the vertical walls 112, 113.

[0045] In the cross section of the structural member 10, the reinforcing member 12 is provided at the center C h The width center line CL of the member body 11 is located within the range of the top plate 111 side. w When the direction in which the vertical wall 112 extends is the height direction, h is the intermediate position in the height direction between the boundary between the top plate 111 and the vertical wall 112 and the boundary between the vertical wall 112 and the flange 114. Similarly, the center C his a middle position in the height direction between the boundary between the top plate 111 and the vertical wall 113 and the boundary between the vertical wall 113 and the flange 115. In the example of FIG. 2, the center C h The reinforcing member 12 is not provided in the range from the flange 114, 115 side to the vertical wall 112. 2 is the height H of the vertical walls 112 and 113 1 It is less than half of that.

[0046] Height H of vertical wall 112 1 is the height direction distance from the boundary between the top plate 111 and the vertical wall 112 to the boundary between the vertical wall 112 and the flange 114. Similarly, the height H 1 is the height direction distance from the boundary between the top plate 111 and the vertical wall 113 to the boundary between the vertical wall 113 and the flange 115. On the other hand, the height H 2 is defined as the height direction distance from the boundary between the top plate 111 and the vertical wall 112 of the member body 11 to the tip of the reinforcing member 12 on the vertical wall 112 side. 2 is defined as the height direction distance from the boundary between the top plate 111 and the vertical wall 113 of the component body 11 to the tip of the reinforcing material 12 on the vertical wall 113 side.

[0047] The reinforcing material 12 includes a first reinforcing layer 121 and a second reinforcing layer 122 .

[0048] The first reinforcing layer 121 is disposed between the component body 11 and the second reinforcing layer 122. The first reinforcing layer 121 is disposed adjacent to the component body 11. The first reinforcing layer 121 is joined to the top plate 111 and the vertical walls 112, 113 of the component body 11.

[0049] The first reinforcing layer 121 is made of a resin having a specific gravity of 0.05 or more and 1.00 or less. The specific gravity here is the specific gravity at a temperature of 23° C. The specific gravity of the first reinforcing layer 121 can be obtained by taking a sample of any size (for example, 50 mm square × 1.0 mm thick) from the first reinforcing layer 121 and measuring the specific gravity of this sample by geometric measurement specified in JIS Z 8807:2012.

[0050] The type of resin constituting the first reinforcing layer 121 is not particularly limited. The first reinforcing layer 121 may be made of, for example, a thermosetting resin such as an epoxy resin or a urethane resin, or may be made of a thermoplastic resin such as polypropylene or polyethylene. The first reinforcing layer 121 is preferably made of a foamed resin. When the first reinforcing layer 121 is made of a foamed resin, the foaming ratio is, for example, 3 times or more and 10 times or less.

[0051] When the first reinforcing layer 121 is made of a foamed resin, the foaming ratio can be calculated using the specific gravity of the resin before foaming and the specific gravity of the resin after foaming. The specific gravity of the resin after foaming can be obtained by the above-mentioned geometric measurement. The specific gravity of the resin before foaming can be estimated from the resin type identified in the first reinforcing layer 121 by known chemical analysis. Alternatively, the ratio of the void portion to the resin portion may be calculated by observing a cross section of the first reinforcing layer 121 using an optical microscope or the like, and the foaming ratio may be estimated from this ratio.

[0052] The second reinforcing layer 122 is laminated on the first reinforcing layer 121. The second reinforcing layer 122 is disposed in direct contact with the first reinforcing layer 121 and is joined to the first reinforcing layer 121. The second reinforcing layer 122 covers the surface of the first reinforcing layer 121 on the side opposite to the component body 11. The second reinforcing layer 122 constitutes the outermost layer of the reinforcing material 12 in a state in which the reinforcing material 12 is joined to the component body 11.

[0053] The second reinforcing layer 122 is made of fiber-reinforced resin. The second reinforcing layer 122 includes a plurality of fiber bodies and a matrix resin reinforced by the fiber bodies. The type of matrix resin is not particularly limited. The matrix resin may be, for example, a thermosetting resin such as an unsaturated polyester resin, an epoxy resin, or a phenolic resin, or may be a thermoplastic resin such as polypropylene or polyethylene. The fiber body is, for example, carbon fiber. The fiber body may be a fiber body other than carbon fiber, such as glass fiber. A known fiber-reinforced resin material can be used as the second reinforcing layer 122.

[0054] In the second reinforcing layer 122, the plurality of fibrous bodies are preferably randomly oriented. That is, in the second reinforcing layer 122, the orientation directions of the plurality of fibrous bodies are preferably various and not aligned in one direction. In this case, the fibrous bodies are, for example, discontinuous fibers having a length of less than 100 mm. In the second reinforcing layer 122, the plurality of fibrous bodies may have a nonwoven fabric-like form.

[0055] However, the multiple fibrous bodies do not have to be randomly oriented in the second reinforcing layer 122. For example, the second reinforcing layer 122 may contain continuous fibers having a length of 100 mm or more as the fibrous bodies. The fibrous bodies may be oriented in one direction or in a cross shape.

[0056] The second reinforcing layer 122 is a fiber reinforced resin containing a plurality of fiber bodies, and therefore has a higher specific gravity than the first reinforcing layer 121, which does not contain fiber bodies. The specific gravity of the second reinforcing layer 122 is greater than 1.00, for example, 1.30 or more. The specific gravity here is the specific gravity at a temperature of 23°C, similar to that of the first reinforcing layer 121. The specific gravity of the second reinforcing layer 122 can be measured by the same method as that of the first reinforcing layer 121. The second reinforcing layer 122 also has a higher elastic modulus (Young's modulus) than the first reinforcing layer 121. The elastic modulus of the second reinforcing layer 122 is, for example, 15 GPa or more.

[0057] In this embodiment, the first reinforcing layer 121 has a thickness t1. The second reinforcing layer 122 has a thickness t2. The sum of the thickness t1 of the first reinforcing layer 121 and the thickness t2 of the second reinforcing layer 122, that is, the thickness of the entire reinforcing material 12, is typically greater than the plate thickness t of the member body 11. The thickness t1 of the first reinforcing layer 121 is preferably greater than the plate thickness t of the member body 11. The thickness t1 of the first reinforcing layer 121 is greater than the thickness t2 of the second reinforcing layer 122. When the thicknesses t1 and t2 of the reinforcing layers 121 and 122 are measured at the same position of the structural member 10, the thicknesses t1 and t2 preferably satisfy 1.3≦t1 / t2. In addition, the thicknesses t1 and t2 preferably satisfy t1 / t2≦9.0. Although not particularly limited, the thickness t1 of the first reinforcing layer 121 is, for example, greater than 1.0 mm. The thickness t1 of the first reinforcing layer 121 may be, for example, less than 5.0 mm.

[0058] The reinforcing material 12 may be bonded to the top plate 111 and the vertical walls 112, 113 by an adhesive. That is, an adhesive layer may be interposed between the first reinforcing layer 121 and the top plate 111 and the vertical walls 112, 113. In this case, for example, after the second reinforcing layer 122 made of fiber-reinforced resin is formed by press molding or the like, a fluid resin material is applied to the second reinforcing layer 122 and hardened to form the first reinforcing layer 121. When a foaming resin material is applied to the second reinforcing layer 122, the first reinforcing layer 121 can be formed by performing a foaming process such as heating. In this way, the reinforcing material 12 separate from the member body 11 is produced. This reinforcing material 12 is bonded to the top plate 111 and the vertical walls 112, 113 by an adhesive.

[0059] However, the reinforcing material 12 may be directly bonded to the top plate 111 and the vertical walls 112, 113 without an adhesive layer. For example, the second reinforcing layer 122 formed by press molding or the like is disposed with a gap from the member body 11, and a resin material is introduced into the gap and cured to form the first reinforcing layer 121. When a foamed resin material is used, the first reinforcing layer 121 is formed by performing a foaming process such as heating. In this case, the first reinforcing layer 121 itself is directly bonded to the top plate 111 and the vertical walls 112, 113.

[0060] [effect] In the structural member 10 according to this embodiment, the reinforcing material 12 is joined to the top plate 111 and the vertical walls 112, 113 of the member body 11. The reinforcing material 12 includes a first reinforcing layer 121 and a second reinforcing layer 122. The first reinforcing layer 121 is made of a resin having a relatively small specific gravity of 1.00 or less. Therefore, even if the first reinforcing layer 121 is made thicker, the weight of the structural member 10 does not increase significantly. Therefore, the first reinforcing layer 121 can increase the bending rigidity of the structural member 10 at the positions of the top plate 111 and the vertical walls 112, 113 with weight efficiency. As a result, during a collision of the vehicle body, a change in the cross-sectional shape of the structural member 10, more specifically, deformation in which the vertical walls 112, 113 bulge outward in the width direction of the structural member 10, can be suppressed.

[0061] In this embodiment, the first reinforcing layer 121 of the reinforcing material 12 is disposed between the member body 11 and the second reinforcing layer 122. The second reinforcing layer 122 is made of a fiber reinforced resin having a relatively high elastic modulus. This can further increase the rigidity of the structural member 10 at the positions of the top plate 111 and the vertical walls 112, 113. Therefore, in the event of a vehicle body collision, changes in the cross-sectional shape of the structural member 10 are more easily suppressed.

[0062] In a structural member, deformation in which both vertical walls bulge outward is likely to occur when the top plate is disposed facing the outside of the vehicle body. The configuration described in this embodiment can suppress such deformation, and can therefore be suitably applied to structural members whose top plate is disposed facing the outside of the vehicle body. The structural member 10 according to this embodiment is, for example, a center pillar (B pillar). In this case, it is preferable that the reinforcing material 12 is provided over 10% or more of the longitudinal length of the member main body 11. However, the structural member 10 may be, for example, other pillars such as a front pillar (A pillar), or may be a bumper beam, a side sill, a side member, or the like.

[0063] In the structural member 10 according to this embodiment, the thickness of the structural member 10 at the positions of the top plate 111 and the vertical walls 112, 113 can be ensured by the first reinforcing layer 121 made of resin, even without thickening the second reinforcing layer 122 made of fiber-reinforced resin. This makes it possible to reduce the amount of fiber used, thereby reducing the CO2 emissions in the manufacture of the structural member 10. 2 Emissions can be reduced.

[0064] The second reinforcing layer 122 may be made of fiber-reinforced resin using recycled carbon fiber or recycled glass fiber. In this case, the CO 2 Emissions can be further reduced.

[0065] In the structural member 10 according to this embodiment, the reinforcing member 12 is disposed at the center C h It is preferable that the reinforcing member 12 is provided within a range on the top plate 111 side with respect to the vehicle body. In other words, it is preferable that the reinforcing member 12 is provided within a range where a compressive force acts on the structural member 10 due to a collision of the vehicle body. This makes it possible to more efficiently suppress changes in the cross-sectional shape of the structural member 10.

[0066] In the structural member 10 according to this embodiment, the thickness t1 of the first reinforcing layer 121 of the reinforcing material 12 is greater than the thickness t2 of the second reinforcing layer 122. The first reinforcing layer 121 has a lower specific gravity than the second reinforcing layer 122 made of fiber-reinforced resin. By making the first reinforcing layer 121 thicker, the weight of the structural member 10 can be reduced while suppressing changes in the cross-sectional shape during a collision.

[0067] It is preferable that the thickness t1 of the first reinforcing layer 121 and the thickness t2 of the second reinforcing layer 122 satisfy 1.3≦t1 / t2≦9.0. This improves the bending rigidity of the reinforcing portion of the structural member 10 by the reinforcing material 12 and reduces the amount of CO during manufacturing. 2 This allows for a good balance between reducing emissions and reducing CO2 emissions.

[0068] In the structural member 10 according to this embodiment, the reinforcing material 12 is joined to the top plate 111 and the vertical walls 112, 113 of the member body 11 by, for example, an adhesive. In this case, the first reinforcing layer 121 can be produced apart from the member body 11, making the work easier than when the first reinforcing layer 121 is directly bonded to the member body 11.

[0069] In the structural member 10 according to this embodiment, the first reinforcing layer 121 of the reinforcing material 12 is preferably made of a foamed resin. This allows the reinforcing material 12 and the structural member 10 including the reinforcing material 12 to be made even lighter.

[0070] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0071] In the above embodiment, the reinforcing member 12 is disposed at the center C h However, in the cross-sectional view of the structural member 10, the reinforcing member 12 is disposed within a range on the top plate 111 side of the vertical walls 112 and 113. h Alternatively, the reinforcing member 12 may extend beyond the center C on one side of the vertical walls 112 and 113 toward the flanges 114 and 115. h On the other side of the vertical walls 112 and 113, the reinforcing member 12 is disposed at the center C h The reinforcing member 12 may be provided beyond the width center line CL of the component body 11. w The positions do not necessarily have to be arranged symmetrically with respect to each other. EXAMPLES

[0072] The present disclosure will be described in more detail below with reference to examples, although the present disclosure is not limited to the following examples.

[0073] [First Example] In order to confirm the effect of the present disclosure, a three-point bending simulation analysis was performed on several models (Example 1 and Comparative Examples 1 to 5) in which a structural member having a hat-shaped member body (hat material) was joined to another structural member (closing plate) using general-purpose CAE analysis software (LS-DYNA, manufactured by Ansys, Inc.). The conditions for Example 1 and Comparative Examples 1 to 5 are shown in Table 1.

[0074] [Table 1]

[0075] Table 1 shows the material and thickness of the hat material, the material and thickness of the closing plate (CP), and the presence or absence of a reinforcing material bonded to the hat material for Example 1 and Comparative Examples 1 to 5, and if a reinforcing material is present, the material and thickness are shown. Conditions (dimensions, etc.) other than those shown in Table 1 were the same for Example 1 and Comparative Examples 1 to 5. As shown in Table 1, in Comparative Examples 1 and 2, the hat material was not reinforced by a reinforcing material, but in Comparative Examples 3 to 5 and Example 1, a reinforcing material was bonded to the top plate and both vertical walls of the hat material from the inside to reinforce the top plate and both vertical walls. In Comparative Example 3, a 1.0 mm thick unidirectional carbon fiber reinforced resin (CF-UD, continuous fiber) was used as a single layer reinforcing material. In Comparative Example 4, a 1.6 mm thick nonwoven carbon fiber reinforced resin (discontinuous CF, randomly oriented discontinuous fiber) was used as a single layer reinforcing material. In Comparative Example 5, a laminate of 2.3 mm thick discontinuous GF and 0.4 mm thick discontinuous CF was used as a reinforcing material. In Example 1, a laminate of 2.8 mm thick foamed resin (specific gravity: 0.45) and 0.4 mm thick discontinuous CF was used as the reinforcing material. In Comparative Example 5, discontinuous GF as the first reinforcing layer was placed between the hat material and discontinuous CF as the second reinforcing layer. In Example 1, foamed resin as the first reinforcing layer was placed between the hat material and discontinuous CF as the second reinforcing layer.

[0076] In this analysis, mass efficiency was evaluated for each of Example 1 and Comparative Examples 1 to 5. Mass efficiency is the value [kg / kN] obtained by dividing the maximum load [kN] obtained in the analysis by the weight [kg] of the entire member. In addition, in this analysis, an assessment tool based on the Life Cycle Assessment (LCA) tool provided by the World Steel Association (WAS) was used for each of Example 1 and Comparative Examples 1 to 5 to calculate the greenhouse gas (GHG) emissions [kg CO 2 The mass efficiency and GHG emissions of Example 1 and Comparative Examples 1 to 5 are shown in FIG.

[0077] As shown in Fig. 3, Example 1 had a higher mass efficiency than Comparative Examples 1 to 5. Therefore, it is found that Example 1 can suppress the change in the cross-sectional shape of the hat material while suppressing the increase in weight, and can exert the effect of the high strength material, compared to Comparative Examples 1 to 5.

[0078] Moreover, in Example 1, the GHG emissions were significantly reduced compared to Comparative Examples 1 and 3 to 5. In Comparative Example 2, the GHG emissions were lower than in Example 1, but the mass efficiency was also significantly lower than in Example 1.

[0079] Therefore, it was confirmed that by using a laminate of a first reinforcing layer made of low-density resin and a second reinforcing layer made of fiber-reinforced resin as a reinforcing material to reinforcing the top plate and both vertical walls of the hat material, it is possible to achieve both improved mass efficiency and reduced GHG emissions.

[0080] [Second Example] For the reinforcing material reinforcing the top plate and both vertical walls of the hat material, a three-point bending simulation analysis similar to that of the first embodiment was carried out while changing the ratio of the thickness t1 of the first reinforcing layer made of resin and the thickness t2 of the second reinforcing layer made of fiber reinforced resin (Examples 2 to 5). The conditions of Examples 2 to 5 are shown in Table 2. Table 2 also shows the conditions of Example 1 and Comparative Example 5 described in the first embodiment.

[0081] [Table 2]

[0082] As shown in FIG. 4, in Examples 1 to 5, the mass efficiency was equal to or greater than that of Comparative Example 5, and the GHG emissions were reduced.

[0083] In Examples 2 to 4, the thickness t2 of the second reinforcing layer is the same, but the thickness t1 of the first reinforcing layer is different. As can be seen from FIG. 4, by reducing the thickness t1 of the first reinforcing layer, the GHG emissions were reduced, but the mass efficiency was also reduced. In Example 4, where t1 / t2 is 1.2, the mass efficiency was slightly increased compared to Comparative Example 5, whereas in Examples 2 and 3, where t1 / t2 exceeds 1.2, the mass efficiency was significantly improved compared to Comparative Example 5. From this result, it was found that if 1.3≦t1 / t2, it is possible to achieve a high degree of both improved mass efficiency and reduced GHG emissions.

[0084] In Examples 1, 5, and 6, the thickness t2 of the second reinforcing layer is the same, but the thickness t1 of the first reinforcing layer is different. The thickness t1 of the first reinforcing layer is larger in Example 5 than in Example 1, and larger in Example 6 than in Example 5. As can be seen from FIG. 4, the GHG emissions increase as the thickness t1 of the first reinforcing layer increases. The mass efficiency of Example 5 increased compared to Example 1, but in Example 6, although the thickness t1 of the first reinforcing layer was larger than that of Example 1, the mass efficiency decreased compared to Example 1.

[0085] The stiffness of the reinforced portion of the structural member increases in proportion to the thickness t1 of the first reinforcement layer. However, if the thickness t1 of the first reinforcement layer is too large relative to the thickness t2 of the second reinforcement layer, the stress applied to the first reinforcement layer also increases, making the first reinforcement layer more likely to deform. As a result, the improvement in stiffness due to reinforcement decreases, and the mass efficiency also decreases. In Example 6, where t1 / t2 is 10.0, the mass efficiency is lower than in Examples 1 and 5, where t1 / t2 is less than 10.0. From this result, it was found that if t1 / t2≦9.0, it is possible to achieve a high degree of both improved mass efficiency and reduced GHG emissions. [Explanation of symbols]

[0086] 10: Structural members 11: Main body of material 111: Tabletop 112,113: Vertical wall 114, 115: Flange 12: Reinforcement 121: First reinforcing layer 122: Second reinforcing layer

Claims

1. A structural member for a vehicle body, comprising: A member body including two vertical walls arranged to face each other, a top plate connecting the two vertical walls, and two flanges connected to the two vertical walls on the opposite side of the top plate and protruding outward from the vertical walls; A reinforcing member joined to the top plate and the two vertical walls; Equipped with The reinforcing material includes a first reinforcing layer made of a resin having a specific gravity of 0.05 or more and 1.00 or less, and a second reinforcing layer made of a fiber-reinforced resin and laminated on the first reinforcing layer, A structural member, wherein the first reinforcing layer is disposed between the member body and the second reinforcing layer and has a thickness greater than a thickness of the second reinforcing layer.

2. 2. The structural member of claim 1, A structural member, wherein the second reinforcing layer includes a plurality of randomly oriented fibrous bodies.

3. 2. The structural member of claim 1, A structural member, wherein in a cross section of the structural member, the reinforcing material is positioned within a range on the top plate side relative to the center of the height direction of the two vertical walls.

4. 2. The structural member of claim 1, A structural member, wherein when the thickness of the first reinforcing layer is t1 and the thickness of the second reinforcing layer is t2, t1 and t2 satisfy 1.3≦t1 / t2≦9.

0.

5. 2. The structural member of claim 1, A structural member, wherein the stiffener is joined to the top plate and the two vertical walls by an adhesive.

6. 2. The structural member of claim 1, A structural member, wherein the first reinforcing layer is made of a foamed resin.

7. 2. The structural member of claim 1, the structural member is a center pillar, A structural component, wherein the reinforcing material is provided over 10% or more of the longitudinal length of the component body.

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