WO2020017645A1 - Vehicle structural member - Google Patents

Abstract

A vehicle structural member that is lighter weight, causes stable axial crush deformation at vehicle impact, and maintains or improves energy absorption performance. This vehicle structural member comprises a metal hollow member, and a plurality of plate-shaped reinforcement members formed from FRP, having each side thereof joined to the inner surface of the hollow member, and being disposed at intervals in the longitudinal direction of the hollow member so as to partition the inner space of the hollow member. In a cross section of the hollow member perpendicular to the longitudinal direction of the hollow member, the minimum width of the outer dimensions of the hollow member is at least 30% of the maximum width of the outer dimensions of the hollow member. Each reinforcement member is disposed such that the plate surface of the reinforcement member is oriented in a direction perpendicular to the longitudinal direction of the hollow member, and at least three reinforcement members are disposed from a longitudinal end section of the hollow member at intervals of 0.74 to 1.84 times the minimum width. Each reinforcement member has a plate thickness of 0.7 to 3.0 mm.

Description

Vehicle structural members

(Cross-reference of related applications)
Priority is claimed on Japanese Patent Application No. 2018-136982, filed on July 20, 2018, the content of which is incorporated herein by reference.

The present invention relates to a vehicle structural member.

In recent years, from the viewpoint of global environmental protection, improvement of fuel efficiency of automobiles has been required. On the other hand, it is required to maintain or improve the collision safety of the vehicle. In order to satisfy these demands, the development of a high-strength and lightweight vehicle body structure has been promoted. The structural members for vehicles, and the frames that form the skeleton of the vehicle body, have also been strengthened and made thinner in the steel plates that form the frames in order to reduce the weight of the vehicle structure while maintaining the conventional collision performance. ing.

Also, in order to improve the collision safety of the vehicle, it is required to improve the energy absorption performance of the front part and the rear part of the vehicle, also called “crushable zone”. For example, in the crushable zone of the front part, there is a component called a front side member. For example, at the time of a frontal collision of a vehicle, a load is input to the front side member mainly from the longitudinal direction (axial direction) of the member. At that time, the front side member undergoes compression bending deformation. In general, in compression bending deformation, only the bent portion buckles and undergoes plastic deformation, but the other portions do not undergo much plastic deformation. On the other hand, the axial crushing deformation in which buckling occurs continuously and deforms in a bellows-like manner has a wide plastic deformation region, and has higher energy absorption efficiency than bending deformation. However, it is difficult to stably generate the axial crush deformation under the condition that the input direction of the load at the time of the collision is not uniquely determined as in a vehicle. Therefore, it is more preferable that a member such as a front side member of the vehicle absorbs energy while performing compression bending deformation at the time of collision.

As a technique aimed at improving energy absorption performance at the time of a vehicle collision, Patent Literature 1 discloses a plurality of ribs such that an inner space of a front portion of a hollow frame member is separated at regular intervals in a member longitudinal direction. A deployed technique is disclosed. Note that no rib is provided at the rear of the hollow frame member.

Patent Literature 2 discloses a welded structure closed-section frame that is used for an automobile body frame, a suspension frame, or the like and that prevents opening or breakage at a welded portion in a collision. In this technique, a plate-like metal reinforcing member is provided in a hollow member. Patent Literature 3 discloses a configuration in which a plurality of reinforcing members are provided in a hollow member (strength member) having a closed cross-sectional structure, and discloses a technique using a synthetic resin as the reinforcing member. Patent Document 4 discloses a technique of attaching a reinforcing member to the inner surface of a hollow member in a vehicle structural member, and discloses that the tensile strength of the hollow member is 980 MPa or more.

JP 2004-182189 A JP 2010-76762 A JP-A-11-342882 JP-A-2017-159896

In Patent Document 1, with respect to the pitch of undulating buckling waves generated when a load is input (buckling mode pitch), the sum of the length of one side of the rectangular cross section of the hollow frame member and the length of the other side is constant. It is disclosed that if there is, even if the ratio of the length of one side to the length of the other side changes, the pitch of the buckling mode does not change. Patent Document 1 discloses that in the case of a square cross section, the length of one side and the pitch of the buckling mode are in a proportional relationship.

However, when the present inventor examined the disclosure content of Patent Document 1, the relationship between the length of the side and the pitch of the buckling mode disclosed in Patent Document 1 holds when a static load is applied. It has been found that this is not the case when a dynamic load simulating an actual car collision is applied. Therefore, even if the rib is arranged inside the hollow frame member based on the disclosure of Patent Document 1, the energy absorption performance may not be sufficiently improved in some cases.

In addition, Patent Documents 2 to 4 disclose that the impact is efficiently absorbed when a load is input and that the load-bearing performance is improved and the weight is reduced. The detailed conditions for causing deformation and improving the energy absorption performance are not sufficiently disclosed. In particular, the detailed configuration such as the arrangement, spacing, number, and plate thickness of the reinforcing members has not been sufficiently disclosed, and there is room for further improving the energy absorption performance of structural members for vehicles.

Specifically, for example, it is required that the vehicle structural members such as the front side member, the rear side member, the crash box, and the extension have high energy absorption performance in a stable manner. Preferably, deformation occurs.

The present invention has been made in view of the above problems, and in a vehicle structural member, while achieving weight reduction, stably generate axial crush deformation at the time of a vehicle collision, and maintain or improve energy absorption performance. Aim.

According to the present invention, in order to solve the above problems, a metal hollow member and each side are joined to an inner surface of the hollow member, and a member longitudinal direction of the hollow member is separated so as to separate an inner space of the hollow member. A plurality of plate-shaped reinforcing members made of FRP, which are arranged at intervals along with each other, and in a cross section perpendicular to the member longitudinal direction of the hollow member, the minimum width in external dimensions of the hollow member is 30% or more of the maximum width in the external dimensions of the hollow member, and each reinforcing member has a direction in which the plate surface of the reinforcing member is perpendicular to the longitudinal direction of the hollow member and the longitudinal direction of the hollow member. The structural member for a vehicle, wherein three or more sheets are arranged at an interval of 0.74 to 1.84 times the minimum width from the end of the vehicle, and the plate thickness of the reinforcing member is 0.7 to 3.0 mm. Provided.

The hollow member has a bending inducing portion in a part in the member longitudinal direction, and the interval between the reinforcing members arranged in the bending inducing portion is the interval between the reinforcing members arranged in portions other than the bending inducing portion. It may be narrower than.

The hollow member has a bending inducing portion in a part in the member longitudinal direction, and the thickness of the reinforcing member arranged in the bending inducing portion is a thickness of the reinforcing member arranged in a portion other than the bending inducing portion. It may be thicker than the plate thickness.

The hollow member has a bending inducing part in a part in the member longitudinal direction, and the tensile strength of the reinforcing member arranged in the bending inducing part is the reinforcing member arranged in a part other than the bending inducing part. May be greater than the tensile strength of the steel.

The FRP may be CFRP or GFRP.

中空 The hollow member may have a tensile strength of 980 MPa or more.

The vehicle structural member may be any of a front side member, a rear side member, an extension, and a crash box.

According to the present invention, in a vehicle structural member, axial crush deformation can be stably generated at the time of a vehicle collision while maintaining weight reduction, and energy absorption performance can be maintained or improved.

It is a perspective view showing the state where the frame for vehicles and other members concerning one embodiment of the present invention were joined. It is a top view showing the state where the frame for vehicles concerning the embodiment and other members were joined. It is a side view showing the state where the frame for vehicles and other members concerning the embodiment were joined. FIG. 2 is a perspective view illustrating a schematic configuration of a vehicle frame according to the embodiment. It is a perspective view showing the shape of the reinforcing member concerning the embodiment. FIG. 2 is a diagram showing a cross section of the vehicle frame according to the same embodiment, which is perpendicular to the member longitudinal direction of the hollow member. FIG. 7 is a sectional view taken along line aa in FIG. 6. FIG. 7 is a sectional view taken along line bb in FIG. 6. It is a figure showing an example of arrangement of a reinforcement member concerning the embodiment. It is a figure showing an example of arrangement of a reinforcement member concerning the embodiment. It is sectional drawing of the hollow member for demonstrating the example of the hole provided in the hollow member which concerns on the embodiment. It is a mimetic diagram showing other examples of the hole provided in the hollow member concerning the embodiment. It is a mimetic diagram showing other examples of the hole provided in the hollow member concerning the embodiment. It is a mimetic diagram showing other examples of the hole provided in the hollow member concerning the embodiment. It is a mimetic diagram showing other examples of the hole provided in the hollow member concerning the embodiment. It is sectional drawing of the hollow member for demonstrating the example of the bead part provided in the hollow member which concerns on the embodiment. It is a mimetic diagram showing other examples of the crevice provided in the hollow member concerning the embodiment. It is a mimetic diagram showing other examples of the crevice provided in the hollow member concerning the embodiment. It is a mimetic diagram showing other examples of the crevice provided in the hollow member concerning the embodiment. It is a mimetic diagram showing other examples of the crevice provided in the hollow member concerning the embodiment. It is a mimetic diagram showing other examples of the crevice provided in the hollow member concerning the embodiment. It is sectional drawing of the hollow member for demonstrating the example of the convex part provided in the hollow member which concerns on the embodiment. It is a schematic diagram which shows the other example of the convex part provided in the hollow member which concerns on the embodiment. It is a schematic diagram which shows the other example of the convex part provided in the hollow member which concerns on the embodiment. It is a schematic diagram which shows the other example of the convex part provided in the hollow member which concerns on the embodiment. It is a schematic diagram which shows the other example of the convex part provided in the hollow member which concerns on the embodiment. It is a schematic diagram which shows the other example of the convex part provided in the hollow member which concerns on the embodiment. It is a schematic diagram which shows an example of the board thickness change part provided in the hollow member which concerns on the embodiment. It is a schematic diagram which shows an example of the thin part provided in the hollow member which concerns on the embodiment. It is sectional drawing of the hollow member for demonstrating the example of the different strength part provided in the hollow member which concerns on the same embodiment. It is a mimetic diagram showing other examples of a different intensity part provided in a hollow member concerning the embodiment. It is a mimetic diagram showing other examples of a different intensity part provided in a hollow member concerning the embodiment. It is a schematic diagram which shows an example of the intensity | strength change part provided in the hollow member which concerns on the embodiment. It is a top view showing the state in the middle of the deformation of the vehicle frame of the comparative example (structure 1). It is a top view showing the state after deformation of the vehicle frame of the comparative example (structure 1). It is a top view showing the state in the middle of the deformation of the vehicle frame of the comparative example (structure 4). It is a top view showing the state after deformation of the vehicle frame of the comparative example (structure 4). It is a top view which shows the state in the middle of deformation | transformation of the vehicle frame of invention example (structure 7). It is a top view which shows the state after deformation | transformation of the vehicle frame of invention example (structure 7). It is the figure which compared the energy absorption performance of each analysis model in a collision simulation.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the specification and the drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted.

<1. Applicable objects of vehicle structural members>
Before describing the configuration of a vehicle frame, which is an example of a vehicle structural member, an application target of the vehicle structural member will be described. The vehicle body provided in a vehicle such as a general automobile can be classified into a front structure (FRONT), a rear structure (REAR), and a cabin structure (CABIN).

(4) The front structure and the rear structure have a function of absorbing and mitigating a shock to the vehicle (shock absorbing function) by crushing the structure by itself during a vehicle collision. That is, in order to ensure the safety of the occupants in the cabin at the time of a vehicle collision, the front structure and the rear structure are required to have a structure that absorbs as much energy as possible due to the collision (collision energy). Therefore, the frames constituting the front structure and the rear structure are required to absorb a large amount of collision energy even when bending or crushing occurs during a collision. The frames used for the front structure and the rear structure are, for example, front side members and rear side members. The front side member includes a front side member rear that forms a rear end portion, and a front side member front that forms a portion on the front side of the rear end portion. The rear side member includes a rear side member rear that constitutes a rear end, and a rear side member front that constitutes a portion on the front side of the rear end.

鋼板 By the way, in order to maintain the collision safety of the vehicle and reduce the weight at the same time, the strength and thickness of the steel sheet forming the vehicle body structure are being promoted. The frames constituting the front structure, the rear structure, and the cabin structure are also being replaced with thinned high-strength steel plates. Specifically, the thickness of the frame formed by the high-strength steel sheet is made by the conventional steel sheet so that at least one of the collision energy absorption and the load-bearing performance is equivalent to the frame formed by the conventional steel sheet. It is set thinner than the frame to be formed. This makes it possible to reduce the weight of the frame while maintaining the collision performance of the high-strength frame equal to that of the conventional frame.

<2. Configuration of Vehicle Frame>
(Components of the frame)
FIG. 1 is a perspective view showing a state in which a vehicle frame 1 according to one embodiment of the present invention and other members are joined. FIG. 2 is a plan view of the state, and FIG. 3 is a side view of the state. The vehicle frame 1 in the examples shown in FIGS. 1 to 3 is a front side member, and the front end of the front side member is joined to a bumper beam 40 via a crash box 30. Usually, two front side members are arranged symmetrically in front of the cabin portion, and FIGS. 1 to 3 show only one of the two front side members. The vehicle frame 1 is an example of a vehicle structural member, and will be simply referred to as a frame 1 below. The frame 1 is preferably applied to members having a front structure and a rear structure, but the vehicle frame 1 may be applied to a member having a cabin structure. Further, the vehicle structural member is applicable not only to automobiles but also to other vehicles and self-propelled machines. Other vehicles and self-propelled machines include, for example, motorcycles, heavy vehicles such as buses or towing vehicles, trailers, railway vehicles, construction machines, mining machines, agricultural machines, general machines, ships, and the like.

As shown in FIGS. 4 to 6, the frame 1 of the present embodiment includes a hollow member 10 made of metal and a plurality of reinforcing members 20 arranged inside the hollow member 10.

The hollow member 10 of the present embodiment is an example of a long structural member, and has a rectangular cross section perpendicular to the longitudinal direction of the member (the X direction in the present embodiment). Although the hollow member 10 of the present embodiment is a square tubular member formed as an integral body, the hollow member 10 is configured by, for example, joining a flat closing plate and a member having a hat-shaped cross section. May be. That is, the configuration of the hollow member 10 is not particularly limited as long as the cross section perpendicular to the member longitudinal direction X is a closed cross section. For example, in the present embodiment, the shape of the hollow member 10 is a rectangular shape, which is an example of a polygonal shape. However, the hollow member 10 may be a polygonal shape other than a rectangle. However, as will be described later, in a cross section perpendicular to the member longitudinal direction X of the hollow member 10, the minimum width W _min on the external dimensions is set to be 30% or more of the maximum width W _max on the external dimensions. It is composed of

中空 As shown in FIG. 6, the hollow member 10 of the present embodiment has four flat portions 11a to 11d. In the following description, among the four plane parts 11a to 11d, the plane part located on the upper side in FIG. 6 is the top part 11a, the plane part located on the right side is the side part 11b, and the plane part located on the lower side is FIG. The bottom portion 11c and the flat portion located on the left side are referred to as side portions 11d. Also, the connecting portion between the two flat portions 11a and 11b, which is the portion between the top surface portion 11a and the side surface portion 11b, is a ridge line portion 11e, and the two flat portion 11b, which is the portion between the side surface portion 11b and the bottom surface portion 11c. , 11c are connected to the ridge 11f, and the connection between the flat portions 11c and 11d, which is the boundary between the bottom 11c and the side 11d, is connected to the ridge 11g, and the boundary between the side 11d and the top 11a. The connecting portion between the two flat portions 11d and 11a, which is a portion formed by the above, is referred to as a ridge portion 11h.

The hollow member 10 is formed of a metal plate. The type of the metal plate is not particularly limited, but is preferably formed of, for example, a metal plate such as a steel plate. Further, from the viewpoint of the collision performance, the plate thickness of the hollow member 10 is preferably 6.0 mm or less in a frame structure often used in large vehicles such as buses, and in a monocoque structure vehicle often used in vehicles of a normal size. It is preferable that it is 2 mm or less. If necessary, the lower limit of the plate thickness may be 0.8 mm, 1.0 mm, or 1.2 mm. Further, the tensile strength of the metal plate constituting the hollow member 10 (hereinafter, referred to as “the tensile strength of the hollow member 10”) is not particularly limited. However, in order to compensate for the overall strength of the frame 1 that can be reduced by weight reduction, the tensile strength of the hollow member 10 is preferably 590 MPa or more. Further, the tensile strength of the hollow member 10 is more preferably 980 MPa or more. If necessary, the upper limit of the tensile strength of the hollow member 10 may be set to 2000 MPa or 1500 MPa.

The reinforcing member 20 is a plate-shaped FRP member. Flanges 21a to 21d are formed on each linear portion of the rectangular plate surface 20a. In the reinforcing member 20 of the present embodiment, the shape of the plate surface 20 a is similar to the shape of a cross section perpendicular to the member longitudinal direction X of the hollow member 10, and the plate surface 20 a is in the member longitudinal direction X of the hollow member 10. It is provided inside the hollow member 10 in a vertical direction. The flange 21a of the reinforcing member 20 is on the inner surface of the top surface 11a of the hollow member 10, the flange 21b is on the inner surface of the side surface 11b of the hollow member 10, the flange 21c is on the inner surface of the bottom surface 11c of the hollow member 10, and the flange 21d is hollow. It is joined to the inner surface of the side surface portion 11d of the member 10, respectively. Thereby, the reinforcing member 20 is fixed to the hollow member 10. The reinforcing member 20 fixed in this manner functions as a so-called bulkhead that covers the inner space of the hollow member 10 in a cross section perpendicular to the member longitudinal direction X. Note that the shape of the reinforcing member 20 is appropriately changed according to the shape of the hollow member 10, the method of joining the hollow member 10, and the like so that the reinforcing member 20 functions as a bulkhead.

Here, the case where the reinforcing member 20 is joined to the inner surface of the hollow member 10 via the flanges 21a to 21d formed on each linear portion (each side) of the rectangular plate surface 20a is illustrated and described. However, the joining method and its mode are not limited to these. For example, the plate surface 20a may be directly joined to the inner surface of the hollow member 10 without forming a flange on each side of the reinforcing member 20 having the rectangular plate surface 20a. The joining range does not necessarily have to be the entire circumference of the reinforcing member 20. For example, it is sufficient that 50% or more of the length of each side of the reinforcing member 20 is joined to the inner surface of the hollow member 10.

(Example of reinforcing member)
The FRP member used as the reinforcing member 20 means a fiber reinforced resin member made of a matrix resin and a composite reinforcing fiber material contained in the matrix resin.

As the reinforcing fiber material, for example, carbon fiber and glass fiber can be used. In addition, a boron fiber, a silicon carbide fiber, an aramid fiber, or the like can be used as the reinforcing fiber material. In the FRP used for the FRP member, examples of the reinforcing fiber substrate serving as the substrate of the reinforcing fiber material include a nonwoven fabric substrate using chopped fibers, a cloth material using continuous fibers, and a unidirectional reinforcing fiber substrate (UD). Material) etc. can be used. These reinforcing fiber bases can be appropriately selected according to the necessity of the orientation of the reinforcing fiber material.

The CFRP member is an FRP member using carbon fiber as a reinforcing fiber material. As the carbon fibers, for example, PAN-based or pitch-based carbon fibers can be used. By using carbon fibers, strength against weight and the like can be efficiently improved.

The GFRP member is an FRP member using glass fiber as a reinforcing fiber material. Although it is inferior in mechanical properties to carbon fiber, it can suppress the electrolytic corrosion of the metal member.

マ ト リ ッ ク ス As the matrix resin used for the FRP member, any of a thermosetting resin and a thermoplastic resin can be used. Examples of the thermosetting resin include an epoxy resin, an unsaturated polyester resin, and a vinyl ester resin. Examples of the thermoplastic resin include polyolefins (polyethylene, polypropylene, and the like) and their acid-modified products, polyamide resins such as nylon 6 and nylon 66, thermoplastic aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate, and polyether sulfone. And styrene resins such as polyphenylene ether and modified products thereof, polyarylate, polyether ketone, polyether ether ketone, polyether ketone ketone, vinyl chloride and polystyrene, and phenoxy resins. Note that the matrix resin may be formed of a plurality of types of resin materials.

と Considering application to metal members, it is preferable to use a thermoplastic resin as the matrix resin from the viewpoint of workability and productivity. Furthermore, by using a phenoxy resin as the matrix resin, the density of the reinforcing fiber material can be increased. Further, the phenoxy resin has a heat structure similar to that of the epoxy resin because the molecular structure is very similar to that of the epoxy resin which is a thermosetting resin. Further, by further adding a curing component, application to a high-temperature environment becomes possible. When the hardening component is added, the addition amount may be appropriately determined in consideration of the impregnating property of the reinforcing fiber material, the brittleness of the FRP member, the tact time, the workability and the like.

(Adhesive resin layer)
When the reinforcing member 20 is formed of an FRP member or the like, an adhesive resin layer is provided between the FRP member and the metal member (the hollow member 10 in the above embodiment), and the FRP member and the metal member are separated by the adhesive resin layer. They may be joined.

種類 The type of the adhesive resin composition forming the adhesive resin layer is not particularly limited. For example, the adhesive resin composition may be either a thermosetting resin or a thermoplastic resin. The types of the thermosetting resin and the thermoplastic resin are not particularly limited. For example, as the thermoplastic resin, polyolefins and acid-modified products thereof, polystyrene, polymethyl methacrylate, AS resin, ABS resin, thermoplastic aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate, polyimide, polyamide, polyamide Use one or more selected from imide, polyether imide, polyether sulfone, polyphenylene ether and modified products thereof, polyphenylene sulfide, polyoxymethylene, polyarylate, polyether ketone, polyether ether ketone, and polyether ketone ketone can do. Further, as the thermosetting resin, for example, one or more selected from an epoxy resin, a vinyl ester resin, a phenol resin, and a urethane resin can be used.

The adhesive resin composition can be appropriately selected according to the characteristics of the matrix resin constituting the FRP member, the characteristics of the reinforcing member 20, or the characteristics of the metal member. For example, by using a resin having a polar functional group or a resin subjected to acid modification or the like as the adhesive resin layer, the adhesiveness is improved.

Thus, by adhering the FRP member to the metal member using the above-described adhesive resin layer, the adhesion between the FRP member and the metal member can be improved. Then, the deformation followability of the FRP member when a load is input to the metal member can be improved. In this case, the effect of the FRP member on the deformed metal member can be more reliably exerted.

The form of the adhesive resin composition used to form the adhesive resin layer may be, for example, a liquid such as powder or varnish, or a solid such as a film.

架橋 Alternatively, a crosslinkable curable resin and a crosslinking agent may be blended with the adhesive resin composition to form a crosslinkable adhesive resin composition. Thereby, the heat resistance of the adhesive resin composition is improved, so that application in a high-temperature environment becomes possible. As the crosslinkable curable resin, for example, a bifunctional or more functional epoxy resin or a crystalline epoxy resin can be used. In addition, an amine, an acid anhydride, or the like can be used as a crosslinking agent. Further, various additives such as various rubbers, inorganic fillers and solvents may be blended in the adhesive resin composition as long as the adhesiveness and physical properties are not impaired.

複合 Combining the FRP member with the metal member is realized by various methods. For example, it is obtained by bonding an FRP to be an FRP member or an FRP molding prepreg that is a precursor thereof to a metal member with the above-described adhesive resin composition, and solidifying (or curing) the adhesive resin composition. . In this case, for example, by performing thermocompression bonding, the FRP member and the metal member can be combined.

The bonding of the FRP or the FRP forming prepreg to the metal member described above can be performed before, during or after forming the part. For example, after a metal material to be processed is formed into a metal member, FRP or a prepreg for FRP molding may be bonded to the metal member. Alternatively, after the FRP or the prepreg for FRP molding is bonded to the workpiece by heat and pressure bonding, the composite material may be obtained by molding the workpiece to which the FRP member is bonded. If the matrix resin of the FRP member is a thermoplastic resin, it is possible to perform molding such as bending on the portion where the FRP member is bonded. When the matrix resin of the FRP member is a thermoplastic resin, a composite batch molding in which the thermocompression bonding step and the molding step are integrated may be performed.

接合 The joining method between the FRP member and the metal member is not limited to the above-described adhesion using the adhesive resin layer. For example, the FRP member and the metal member may be mechanically joined. More specifically, holes for fastening are formed at positions corresponding to the FRP member and the metal member, respectively, and these are fastened through the holes by fastening means such as bolts and rivets, so that the FRP member and the metal member are fastened. The member may be joined. Alternatively, the FRP member and the metal member may be joined by known joining means. Further, the FRP member and the metal member may be jointly joined by a plurality of joining means. For example, the bonding by the adhesive resin layer and the fastening by the fastening means may be used in combination.

(Metal members and their surface treatment)
The metal member according to the present invention may be plated. Thereby, corrosion resistance is improved. In particular, when the metal member is a steel material, it is more preferable. The type of plating is not particularly limited, and known plating can be used. For example, as a coated steel sheet (steel material), a hot-dip galvanized steel sheet, a hot-dip galvanized steel sheet, a Zn-Al-Mg based alloy coated steel sheet, an aluminum plated steel sheet, an electro-galvanized steel sheet, an electric Zn-Ni based alloy-coated steel sheet, or the like can be used. Can be used.

金属 The metal member may have a surface coated with a film called a chemical conversion treatment. Thereby, corrosion resistance is further improved. As the chemical conversion treatment, a generally known chemical conversion treatment can be used. For example, as the chemical conversion treatment, a zinc phosphate treatment, a chromate treatment, a chromate-free treatment, or the like can be used. Further, the above-mentioned film may be a known resin film.

金属 Also, the metal member may be a member to which a generally known coating is applied. Thereby, corrosion resistance is further improved. As the coating, a known resin can be used. For example, as the coating, an epoxy resin, a urethane resin, an acrylic resin, a polyester resin, a fluororesin, or the like as a main resin can be used. In addition, generally known pigments may be added to the coating, if necessary. The coating may be a clear coating to which no pigment is added. Such coating may be applied to the metal member in advance before compounding the FRP member, or may be applied to the metal member after compounding the FRP member. Further, the metal member may be coated in advance, the FRP member may be composited, and then the coating may be performed. The paint used for painting may be a solvent-based paint, a water-based paint, a powder paint, or the like. As a method for applying the coating, a generally known method can be applied. For example, electrodeposition coating, spray coating, electrostatic coating, immersion coating, or the like can be used as a coating application method. Electrodeposition coating is suitable for covering the end surfaces and gaps of metal members, and therefore has excellent corrosion resistance after coating. Further, by applying a generally known chemical treatment such as zinc phosphate treatment or zirconia treatment to the surface of the metal member before coating, the adhesion of the coating film is improved.

<3. Example of arrangement of reinforcing members>
As shown in FIG. 4, the plurality of reinforcing members 20 are arranged at intervals from the end of the hollow member 10 in the member longitudinal direction X to the entire region in the member longitudinal direction X. More specifically, as shown in FIGS. 7 and 8, each reinforcing member 20 in the present embodiment has an interval P from the front end 10 a to the rear end 10 b of the hollow member 10 so as to separate the inner space of the hollow member 10. It is arranged in.

Here, in this specification, the minimum width and the maximum width in the outer dimensions of the hollow member 10 in a cross section perpendicular to the member longitudinal direction X of the hollow member 10 are used as a reference. In the case of the present embodiment, the outer dimension on the short side of the substantially rectangular cross section shown in FIG. 6 is the minimum width W _min , and the outer dimension width on the long side of the substantially rectangular cross section is the maximum width W _max . In the cross section of the hollow member 10 of the present embodiment, a pair of opposed short sides and a pair of opposed long sides are configured to be equal to each other. Here, in the cross section of the hollow member 10 perpendicular to the member longitudinal direction X, the minimum width W _min on the external dimensions is configured to be 30% or more of the maximum width W _max on the external dimensions. . The ratio of the minimum width W _min and a maximum width W _max of the outer shape dimension of the external dimensions (i.e., flat ratio of the section) relates, if the minimum width W _min is not more than 30% of the length of the maximum width W _max, hollow The member 10 may not be stably deformed by axial crushing, and is not effective as a shock absorbing member. If necessary, the minimum width W _min may be 35% or 40% or more of the maximum width W _max . From the definition, the minimum width W _min does not become larger than the maximum width W _max .

The interval P between the reinforcing members 20 arranged inside the hollow member 10 is 0.74 times to 1.84 times the minimum width W _min of the external dimensions of the hollow member 10. In other words, in the present embodiment, each reinforcing member 20 extends along the member longitudinal direction X of the hollow member 10 at an interval P of 0.74 times to 1.84 times the minimum width W _min on the external dimensions of the hollow member 10. Is arranged. In the case of the hollow member 10 having a shape that changes in the member longitudinal direction X, the minimum width W _min is defined based on the cross-sectional shape of the hollow member 10 at a position where the area of the cross section perpendicular to the member longitudinal direction X is the smallest. .

As will be described later in the embodiment, when the interval P between the reinforcing members 20 is 0.74 times to 1.84 times the minimum width W _min of the outer dimensions of the hollow member 10, the longitudinal direction of the hollow member 10 When a high load is input from X, axial crush deformation occurs in the hollow member 10 stably. The reason why such deformation occurs is as follows.

When a high load is input from the front end 10a of the hollow member 10, the first reinforcement member 20 closest to the front end 10a is located at the position where the first reinforcement member 20 is arranged because the reinforcement effect is large at the position where the reinforcement member 20 is disposed. The hollow member 10 is deformed in a portion forward of the hollow member 10. Thereafter, the deformation of the hollow member 10 proceeds toward the rear end 10b, and the deformation of the hollow member 10 where the first reinforcing member 20 is disposed is started. Since the FRP has low ductility, the first reinforcing member 20 breaks at this stage. That is, the reinforcing effect is lost at the place where the first reinforcing member 20 is arranged, and the hollow member 10 at the place is easily deformed.

On the other hand, at the places where the second and subsequent reinforcing members 20 are arranged, the reinforcing members 20 are not broken, and thus the reinforcing effect is maintained without being lost. That is, at the place where the second and subsequent reinforcing members 20 are arranged, the hollow member 10 is in a state where it is difficult to deform. For this reason, until the deformation of the hollow member 10 at the location where the first reinforcing member 20 that has been broken is advanced sufficiently, the deformation amount of the hollow member 10 at the location where the second and subsequent reinforcing members 20 are located is It is getting smaller. Then, after the deformation in the front region of the place where the second reinforcing member 20 is disposed has sufficiently progressed, the deformation of the hollow member 10 where the second reinforcing member 20 is disposed starts. As described above, since the FRP has low ductility, the second reinforcing member 20 breaks at this stage. Thereby, the reinforcing effect is lost at the place where the second reinforcing member 20 is arranged, and the hollow member 10 at the place is easily deformed.

(4) The above-described deformation occurs repeatedly even in the places where the third and subsequent reinforcing members 20 are arranged. That is, in the frame 1 of the present embodiment, the deformation of the hollow member 10 is caused while the reinforcing members 20 arranged along the member longitudinal direction X of the hollow member 10 are sequentially broken from the end on the load input side. proceed. Thereby, when a load is input from the member longitudinal direction X of the hollow member 10, axial crush deformation can be generated stably, and high energy absorption performance can be stably obtained.

On the other hand, when the interval P between the reinforcing members 20 does not satisfy 0.74 times to 1.84 times the minimum width W _min of the external dimensions of the hollow member 10, stable axial crush deformation occurs in the hollow member 10. There is no fear. If the interval P is shorter than 0.74 times the minimum width W _min of the external dimensions of the hollow member 10, the stiffness becomes too high, and there is a possibility that buckling does not occur between the reinforcing members 20. If the interval P is more than 1.84 times the minimum width W _min of the external dimensions of the hollow member 10, the space between the reinforcing members 20 is too long, so that lateral bending deformation occurs at one location and does not result in axial crush deformation. There is fear. If necessary, the lower limit of the interval P between the reinforcing members 20 may be set to 0.80 times, 0.85 times, or 0.90 times the minimum width W _min of the external dimensions of the hollow member 10. If necessary, the upper limit of the interval P between the reinforcing members 20 may be set to 1.60 times, 1.50 times, or 1.40 times the minimum width W _min of the external dimensions of the hollow member 10.

In addition, from the viewpoint of increasing the weight efficiency of the energy absorption performance, the tensile strength of the FRP member constituting the reinforcing member 20 (hereinafter, referred to as “the tensile strength of the reinforcing member 20”) is preferably 100 MPa or more. If necessary, the upper limit of the tensile strength may be 2500 MPa or 2000 MPa. Further, as shown in the embodiments described later, the plate thickness of the reinforcing member 20 is preferably 0.7 to 3.0 mm. The lower limit of the plate thickness of the reinforcing member 20 may be 0.8 mm, 0.9, or 1.0 mm. The upper limit of the plate thickness may be 2.9 mm, 2.8 mm, 2.4 mm, or 2.0 mm.
The ductility of a metal plate such as a steel plate is generally good. For this reason, when the reinforcing member 20 is a metal plate, the reinforcing member 20 as described above does not break, so that high energy absorption performance cannot be stably obtained. For this reason, the reinforcing member 20 needs to be an FRP member.

Although the arrangement of the reinforcing members 20 according to the present embodiment has been described above, the arrangement of the reinforcing members 20 is not limited to the example illustrated in FIG. For example, as shown in FIG. 9, each reinforcing member 20 may not be arranged over the entire region in the member longitudinal direction X. In the example illustrated in FIG. 9, the reinforcing member 20 has an end on the load input side (the front end 10 a in the present embodiment) among the front part and the rear part having the center position in the member longitudinal direction X of the hollow member 10 as a boundary. Located only on the front. Even in this case, in the area where the reinforcing member 20 is arranged, axial crush deformation can be stably generated when a load is input. From the viewpoint of stably generating axial crushing deformation at the time of load input, three or more sheets at a distance P from the load input side end (front end 10a) at the front portion in the member longitudinal direction X of the hollow member 10. What is necessary is just to arrange the reinforcement member 20. Further, in the member longitudinal direction X of the hollow member 10, the reinforcing member 20 is preferably arranged within a range of 15%, 20%, or 30% from the end (front end 10a) on the load input side. More preferably, the number of the reinforcing members 20 is 4 or more, 5 or more, or 6 or more.

In the above-described embodiment, the interval P between the reinforcing members 20 is constant along the member longitudinal direction X of the hollow member 10, but the interval P is the minimum width W _{min in} the outer dimensions of the hollow member 10. As long as it is within the range of 0.74 times to 1.84 times, the interval P may not be constant along the member longitudinal direction X as shown in FIG. In the example shown in FIG. 10, the interval between the reinforcing members 20 arranged at the front portion in the member longitudinal direction X of the hollow member 10 and the interval between the reinforcing members 20 arranged at the rear portion are different.

The shape of the hollow member 10 is appropriately changed depending on the use of the structural member for a vehicle. However, the portion that is easily bent and deformed according to the shape of the hollow member 10 and the other portions are reinforced. By changing the interval P, the plate thickness, the strength, and the like of the members 20, a portion where bending deformation is likely to occur may be mainly reinforced. Thereby, it is possible to generate axial crush deformation having high energy absorption efficiency in a portion where bending deformation has conventionally occurred and energy absorption efficiency has not always been high. In this specification, a portion where such bending deformation is likely to occur is referred to as a “bending inducing portion”.

間隔 It is preferable that the interval P between the reinforcing members 20 arranged in the bending inducing section is narrower than the interval P between the reinforcing members 20 arranged in portions other than the bending inducing section. Thereby, the reinforcing effect in the bending inducing portion is enhanced, and axial crush deformation can be more stably generated. For the same reason, it is preferable that the plate thickness of the reinforcing member 20 arranged in the bending inducing portion is larger than the plate thickness of the reinforcing member 20 arranged in a portion other than the bending inducing portion. Further, for the same reason, it is preferable that the tensile strength of the reinforcing member 20 arranged in the bending inducing section is higher than the tensile strength of the reinforcing member 20 arranged in a portion other than the bending inducing section. In addition, the methods for setting the interval P, the plate thickness, the tensile strength, and the like in the bending inducing section as described above may be appropriately combined.

<4. Example of bending inducer>
Next, an example of the bending inducing section provided in the hollow member 10 will be described. For example, a hole, a concave portion, a convex portion, a plate thickness change portion, a different strength portion, and the like provided in the hollow member 10 realize a function as a bending inducing portion. The portion provided with any one of the hole, the concave portion, the convex portion, and the plate thickness changing portion is a portion where the cross-sectional coefficient of the hollow member 10 changes in the member longitudinal direction X of the hollow member 10. In a portion of the hollow member 10 where the section modulus changes in the member longitudinal direction X, the bending stress generated in the hollow member 10 by the same bending moment changes, so that bending of the hollow member 10 is induced in the portion. More specifically, in a portion of the hollow member 10 having a relatively small section modulus in the longitudinal direction X of the member, the bending stress in the portion is relatively large, so that the portion is bent. Further, for a portion of the hollow member 10 having a relatively large section modulus in the member longitudinal direction X, the section modulus of a portion including the region before and after the hollow member 10 in the member longitudinal direction X is relatively small. . Therefore, bending occurs at the boundary between the region and the portion where the section modulus is relatively large.

The different strength portion is a portion where the yield strength of the hollow member 10 changes in the member longitudinal direction X of the hollow member 10. In a portion of the hollow member 10 where the yield strength changes in the member longitudinal direction X, plastic deformation of the hollow member 10 in the portion is induced. For example, in a portion of the hollow member 10 where the yield strength is relatively small in the member longitudinal direction X, plastic deformation in the portion occurs first in the hollow member 10, so that bending occurs in the portion. Further, for a portion of the hollow member 10 where the yield strength is relatively large in the member longitudinal direction X, the yield strength of the portion including the region before and after the hollow member 10 in the member longitudinal direction X is relatively small. . Therefore, bending occurs at the boundary between the region and the portion where the yield strength is relatively large.

Further, even if the hollow member 10 does not include a hole, a concave portion, a convex portion, a plate thickness change portion, a different strength portion, and the like that realize the function as the bending inducing portion described above, the load applied to the hollow member 10 When the direction of the input can be specified to some extent, there is a region where the bending moment is maximum in the hollow member under the influence of the constraint of the peripheral member joined to the hollow member 10, and bending occurs in the region. Therefore, when the bending moment generated in the hollow member 10 can be specified, the region where the bending moment is maximum also has a function as the bending inducing portion.

Hereinafter, a specific example of the bending inducing section provided in the hollow member 10 will be described.

(Hole)
FIG. 11 is a cross-sectional view of the hollow member 10A for explaining an example of a hole provided in the hollow member 10A according to the present embodiment. As shown in FIG. 11, a hole 50 is provided in the side surface 11b. The section modulus of the hollow member 10A in the portion where the hole 50 is provided is lower than the section modulus of the hollow member 10A in the portion before and after the portion where the hole 50 is provided. Therefore, when the collision load F shown in FIG. 11 is input to the hollow member 10A, the hollow member 10A bends at the portion where the hole 50 is provided so that the hole 50 is bent inside. That is, in the member longitudinal direction X of the hollow member 10A, a portion of the hollow member 10A where the hole 50 is provided becomes a bending inducing portion provided in the hollow member 10A.

形状 Further, the shape and arrangement of the holes are not limited to the examples described above. 12 to 15 are schematic diagrams showing other examples of the hole provided in the hollow member 10A according to the present embodiment. As shown in FIG. 12, a circular hole 50a may be provided in the side surface 11b. Further, as shown in FIG. 13, a plurality of holes 50b may be provided in the side surface 11b. In this case, for example, a plurality of holes 50b may be provided side by side in a direction crossing the member longitudinal direction X of the hollow member 10A. In this case, when the collision load is input, the hollow member 10A is easily bent and deformed toward the side surface 11b with the hole 50b as a starting point of bending.

As shown in FIG. 14, a hole 50c extending in a direction transverse to the member longitudinal direction X of the hollow member 10A may be provided in the side surface 11b. In this case, when a collision load is input, the hollow member 10A bends and deforms toward the side surface 11b with the hole 50c as a starting point of bending. The shape of the hole 50c is not limited to the rounded rectangle shown in FIG. 14, and may be any shape. The direction transverse to the member longitudinal direction X of the hollow member 10A described above is not limited to the direction orthogonal to the member longitudinal direction X of the hollow member 10A as shown in FIGS.
Further, the portion where the hole 50 is provided is not limited to the side surface 11b. For example, the hole 50 may be provided in the top surface 11a, the bottom surface 11c, or the side surface 11d.

穴 Also, as shown in FIG. 15, a hole 50d may be provided in the ridge 11e. Thereby, since the section modulus of the portion provided with the hole 50d in the member longitudinal direction X in the hollow member 10A is significantly reduced, the portion provided with the hole 50d is easily bent as a starting point of bending.

(Recess)
FIG. 16 is a cross-sectional view of the hollow member 10B for explaining an example of a bead portion provided in the hollow member according to the present embodiment. Note that the bead portion 51 is an example of a concave portion in the present embodiment. As shown in FIG. 16, a bead part 51 is provided on the side surface part 11b. The section modulus of the hollow member 10B at the portion where the bead portion 51 is provided is lower than the section modulus of the hollow member 10B at the portion before and after the portion where the bead portion 51 is provided. Therefore, when the collision load F shown in FIG. 16 is input to the hollow member 10B, the hollow member 10B bends at the portion where the bead portion 51 is provided, such that the bead portion 51 is bent inside. That is, in the member longitudinal direction X of the hollow member 10B, a portion of the hollow member 10B where the bead portion 51 is provided serves as a bending inducing portion provided in the hollow member 10B.

Note that the shape and arrangement of the concave portions are not limited to the examples described above. 17 to 20 are schematic views showing other examples of the recess provided in the hollow member 10B according to the present embodiment. The concave portion here means a concave portion such as an emboss or a bead provided in the side surface portion 11b of the hollow member 10B. As shown in FIG. 17, a circular concave portion 51a may be provided on the side surface portion 11b.

Also, as shown in FIG. 18, a plurality of recesses 51b may be provided on the side surface 11b. In this case, for example, a plurality of concave portions 51b may be provided side by side in a direction crossing the member longitudinal direction X of the hollow member 10B. In this case, when the collision load is input, the hollow member 10B is easily bent and deformed toward the side surface portion 11b with the plurality of concave portions 51b serving as a starting point of bending.

Further, as shown in FIG. 19, a bead portion 51c extending in a direction crossing the member longitudinal direction X of the hollow member 10B may be provided on the side surface portion 11b. In this case, when a collision load is input, the hollow member 10B is bent and deformed toward the side surface 11b with the bead portion 51c as a starting point of bending. Note that the shape of the bead portion 51c is not limited to the rounded rectangle shown in FIG. 19, and may be any shape.
Note that the direction crossing the member longitudinal direction X of the hollow member 10B described above is not limited to the direction orthogonal to the member longitudinal direction X of the hollow member 10B as shown in FIG.
Further, the portion where the concave portion 51 is provided is not limited to the side surface portion 11b. For example, the concave portion 51 may be provided on the top surface portion 11a, the bottom surface portion 11c, or the side surface portion 11d.

凹 部 Also, as shown in FIG. 20, a concave portion 51d may be provided in the ridge line portion 11e. Thus, the section modulus of the hollow member 10B in the member longitudinal direction X where the concave portion 51d is provided significantly changes, so that the portion provided with the concave portion 51d easily bends and deforms as a starting point of bending.

FIG. 21 is a schematic view showing another example of the recess provided in the hollow member 10B according to the present embodiment. As shown in FIG. 21, concave portions 51e and 51f extending in the member longitudinal direction X of the hollow member 10B may be provided side by side along the member longitudinal direction X of the hollow member 10B. In this case, bending occurs in a portion 510 of the hollow member 10B between the concave portion 51e and the concave portion 51f in the member longitudinal direction X. That is, since the section of the hollow member 10B where the concave portions 51e and 51f are provided and the portion 510 between the concave portion 51e and the concave portion 51f have different sectional coefficients, the portion 510 is bent when the collision load is input. Bending deformation occurs as a starting point of. In addition, the portion 510 may be formed with a concave portion, a convex portion described later, a thin portion, a different strength portion, or the like. In addition, the concave portion 51e and the concave portion 51f do not necessarily have to be arranged in series as shown in FIG. Further, the concave portion 51e and the concave portion 51f do not necessarily need to extend in the member longitudinal direction X of the hollow member 10B.

(Convex)
FIG. 22 is a cross-sectional view of the hollow member 10C for explaining an example of a protrusion provided on the hollow member 10C according to the present embodiment. As shown in FIG. 22, a protrusion 52 is provided on the side surface 11b. The section modulus of the hollow member 10C at the portion where the protrusion 52 is provided is higher than the section modulus of the hollow member 10C at the portion before and after the portion where the protrusion 52 is provided. Therefore, when the collision load F shown in FIG. 22 is input to the hollow member 10C, a portion of the region 6a or the region 6b before and after the convex portion 52 in the member longitudinal direction X of the hollow member 10C has a lowest section modulus. , So that the convex portion 52 is on the inside of the bend. The area 6a and the area 6b are areas where a change in the section modulus of the hollow member 10C in the Y direction occurs. That is, in the member longitudinal direction X of the hollow member 10C, a portion of the hollow member 10C including the convex portion 52 and the regions 6a and 6b before and after the convex portion 52 serves as a bending inducing portion provided in the hollow member 10C.

In the example illustrated in FIG. 22, the protrusion 52 is provided on the side surface 11 b, but the protrusion 52 may be provided on, for example, the top surface 11 a, the bottom surface 11 c, or the side surface 11 d. More specifically, when the convex portion 52 is provided on the top surface portion 11a, the bottom surface portion 11c, or the side surface portion 11d on the same cross section in a part of the hollow member 10C in the member longitudinal direction X, the hollow member 10C Since the section modulus in the member longitudinal direction X changes at the portion where the convex portion 52 is provided, bending of the hollow member 10C may occur at the portion where the convex portion 52 is provided. Therefore, also in this case, the convex portion 52 becomes a bending inducing portion.

Further, the shape and arrangement of the convex portions are not limited to the above-described example. FIGS. 23 to 26 are schematic views showing other examples of the convex portion provided on the hollow member 10C according to the present embodiment. The convex portion here is realized, for example, by processing the hollow member 10C. That is, such a convex portion may be provided by deforming a part of the steel plate constituting the hollow member 10C. As shown in FIG. 23, a circular convex portion 52a may be provided on the side surface portion 11b.

Also, as shown in FIG. 24, a plurality of protrusions 52b may be provided on the side surface 11b. In this case, for example, a plurality of convex portions 52b may be provided side by side in a direction crossing the member longitudinal direction X of the hollow member 10C. In this case, at the time of input of a collision load, any one of the regions before and after the plurality of protrusions 52b in the member longitudinal direction X of the hollow member 10C serves as a starting point of bending, and the hollow member 10C is easily bent and deformed toward the side surface 11b. Become.

As shown in FIG. 25, a protrusion 52c extending in a direction crossing the member longitudinal direction X of the hollow member 10C may be provided on the side surface 11b. In this case, at the time of input of a collision load, the hollow member 10C is bent and deformed toward the side surface portion 11b with any one of the regions before and after the convex portion 52c in the member longitudinal direction X of the hollow member 10C as a starting point of bending. The shape of the projection 52c is not limited to the rounded rectangle shown in FIG. 25, and may be any shape. It should be noted that the direction transverse to the member longitudinal direction X of the hollow member 10C described above is not limited to the direction orthogonal to the member longitudinal direction X of the hollow member 10C as shown in FIG. Further, the portion where the convex portion 52 is provided is not limited to the side surface portion 11b. For example, the projection 52 may be provided on the top surface 11a, the bottom surface 11c, or the side surface 11d.

凸 Also, as shown in FIG. 26, the projection 52d may be provided on the ridge 11e. Thereby, the section modulus of the portion of the hollow member 10C where the convex portion 52d is provided in the member longitudinal direction X changes remarkably, so that the portion where the convex portion 52d is provided easily bends as a starting point of bending.

FIG. 27 is a schematic view showing another example of the projection provided on the hollow member 10C according to the present embodiment. As shown in FIG. 27, the convex portions 52e and 52f extending in the member longitudinal direction X of the hollow member 10C may be provided side by side along the member longitudinal direction X of the hollow member 10C. In this case, bending occurs in a portion 520 of the hollow member 10C between the convex portion 52e and the convex portion 52f in the member longitudinal direction X. That is, in the hollow member 10C, the section provided with the projections 52e and 52f and the section 520 between the projection 52e and the projection 52f have different cross-sectional coefficients. Bending deformation occurs with 520 as the starting point of bending. Further, in the portion 520, the above-described concave portion, convex portion, or a thin portion or a different strength portion described later may be formed. In addition, the convex part 52e and the convex part 52f do not necessarily need to be lined up in series, as shown in FIG. In addition, the protrusion 52e and the protrusion 52f do not necessarily need to extend in the member longitudinal direction X of the hollow member 10C.

(Thickness change part / thin part)
Further, the side surface portion 11b may be provided with a plate thickness changing portion as a configuration for realizing the bending inducing portion. FIG. 28 is a schematic diagram illustrating an example of a plate thickness changing portion provided in the hollow member 10D according to the present embodiment. Here, the plate thickness change portion means a portion where the plate thickness changes in the member longitudinal direction X of the hollow member 10D. As shown in FIG. 28, the hollow member 10D includes a first thick part 111 and a second thick part 112. The first thick part 111 is provided on the end side of the hollow member 10D, and the second thick part 112 is provided continuously with the first thick part 111 along the member longitudinal direction X of the hollow member 10D. The thickness of the steel plate differs between the first plate thickness portion 111 and the second plate thickness portion 112. The relationship between the plate thicknesses is not particularly limited.

In this case, as shown in FIG. 28, the boundary between the first plate thickness portion 111 and the second plate thickness portion 112 becomes the plate thickness change portion 113. The section modulus of the hollow member 10D in the member longitudinal direction X changes in the plate thickness changing portion 113. That is, the thickness change portion 113 corresponds to a bending inducing portion. Therefore, when a collision load is input to the hollow member 10D, the hollow member 10D bends at the plate thickness change portion 113.

曲 げ The bending inducing section may be realized by, for example, a thin wall section. FIG. 29 is a schematic diagram illustrating an example of a thin portion provided in the hollow member 10D according to the present embodiment. As shown in FIG. 29, a thin portion 114 having a relatively smaller thickness than other portions is provided on the side surface portion 11b in the longitudinal direction X of the hollow member 10D. The section modulus of the hollow member 10D in the portion including the thin portion 114 is lower than the section modulus of the hollow member 10D in the portion before and after the portion in which the thin portion 114 is provided. That is, the portion of the hollow member 10D where the thin portion 114 is provided corresponds to the bending inducing portion. Therefore, when a collision load is input to the hollow member 10D, the hollow member 10D bends at the portion where the thin portion 114 is provided so that the thin portion 114 is bent inside.

中空 The hollow member 10D having such a plate thickness change portion may be formed by, for example, a work plate made of cutting, pressing, and tailored blank. Such a work plate may be a tailor weld blank (TWB) having a weld line. Further, the plate to be processed may be a tailor rolled blank (TRB) provided in a manner that the plate thickness is varied by a rolling roll. In the case of TWB, the difference thickness at the plate thickness change portion can be 0.2 mm or more. In the TRB, the thickness change amount in the thickness change portion per the longitudinal direction of the member can be 0.1 mm / 100 mm or more.

(Different strength part / Strength change part)
FIG. 30 is a cross-sectional view of the hollow member 10E for explaining an example of the different strength portion provided in the hollow member 10E according to the present embodiment. As shown in FIG. 30, a different strength portion 53 is provided on the side surface portion 11b. The different strength portion 53 is provided, for example, by partially performing heat treatment such as welding, quenching, or tempering on the hollow member 10E. The yield strength of the hollow member 10E at the portion where the different strength portion 53 is provided is different from the yield strength of the hollow member 10E at the portion before and after the portion where the different strength portion 53 is provided. Therefore, when the collision load F shown in FIG. 30 is input to the hollow member 10E, the different-strength portion 53 is bent so as to be inside the different-strength portion 53 or in the vicinity of the different-strength portion 53. That is, in the member longitudinal direction X of the hollow member 10E, a portion including the different strength portion 53 of the hollow member 10E becomes a bending inducing portion provided in the hollow member 10E. This bending is a bending caused by plastic deformation of the different strength portion 53 or a region near the different strength portion 53.

In the example shown in FIG. 30, the different strength portion 53 is provided on the side surface portion 11b, but the different strength portion 53 may be provided on the top surface portion 11a, the bottom surface portion 11c, or the side surface portion 11d, for example. . More specifically, when the different strength portion 53 is provided on the top surface portion 11a, the bottom surface portion 11c, or the side surface portion 11d on the same cross section in a part of the hollow member 10 in the member longitudinal direction X, In this case, the strength of the side surface portion 11b is lowest. Then, bending of the hollow member 10 </ b> E with the side surface portion 11 b bent inside may occur in the different strength portion 53. Therefore, also in this case, the different strength portion 53 becomes a bending inducing portion.

配置 Also, the arrangement of the different strength portions is not limited to the example described above. FIG. 31 and FIG. 32 are schematic diagrams illustrating another example of the different strength portion provided in the hollow member 10E according to the present embodiment. The different strength portion here is realized by welding, heat treatment, or the like to the work plate forming the hollow member 10E.

異 As shown in FIG. 31, different strength portions 120 are provided along the circumferential direction of the cross section with respect to the member longitudinal direction X of the hollow member 10E. Also in this case, the portion of the hollow member 10E where the different strength portion 120 is provided corresponds to the bending inducing portion. Therefore, when a collision load is input to the hollow member 10E, the hollow member 10E bends at the portion where the different strength portion 120 is provided so that the different strength portion 120 is bent inside.

Note that, as shown in FIG. 32, the different strength portion may be partially provided on at least one of the wall portions constituting the cross section of the hollow member 10E, such as the side surface portion 11b. Even in such a case, when a collision load is input to the hollow member 10E, the hollow member 10E bends at a portion where the different strength portion 121 is provided so that the different strength portion 121 is bent inside.

曲 げ The bending inducing section may be realized by, for example, a strength changing section. FIG. 33 is a schematic diagram illustrating an example of a strength changing portion provided in the hollow member 10E according to the present embodiment. As shown in FIG. 33, the hollow member 10E includes a first strength part 122 and a second strength part 123. The first strength portion 122 is provided on the end side of the hollow member 10E, and the second strength portion 123 is provided continuously with the first strength portion 122 along the member longitudinal direction X of the hollow member 10E. The yield strength of the steel sheet differs between the first strength part 122 and the second strength part 123. The magnitude relation of the yield strength is not particularly limited.

In this case, as shown in FIG. 33, the boundary between the first strength part 122 and the second strength part 123 becomes the strength change part 124. In the strength changing portion 124, the yield strength of the hollow member 10E in the member longitudinal direction X changes. That is, the strength changing section 124 corresponds to a bending inducing section. Therefore, when a collision load is input to the hollow member 10E, the hollow member 10E bends at the strength changing portion 124.

(combination)
A plurality of examples of the bending inducing section shown above may be combined. For example, a bending inducing portion may be realized by a combination of at least two or more of the above-described concave portion, convex portion, hole portion, plate thickness changing portion, thin portion, different strength portion, and strength changing portion.

(Example of applicable material)
The hollow member of the present embodiment can be applied to, for example, a front side member, a rear side member, an extension, a crash box, or the like, which is a vehicle structural member required to have an impact absorbing function.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to the embodiments. It is apparent that those skilled in the art to which the present invention pertains can conceive various changes or modifications within the scope of the technical idea described in the appended claims. It is understood that these also belong to the technical scope of the present invention.

衝突 A collision simulation was performed to evaluate the energy absorption performance of the frame according to the present invention. The analysis model is composed of a bumper beam and a frame as shown in FIGS. 1 to 3, the cross section of the hollow member is rectangular, and the outer dimensions are 76 mm in width and 200 mm in height. In addition, a plurality of analysis models are created under the conditions shown in Table 1 below. The weight reduction rate in Table 1 is obtained by standardizing the weight of each structure by the weight of the structure 1.

構造 Structures 1 and 2 in Table 1 above are structures in which the reinforcing member 20 is not provided, and structure 2 is a structure in which the thickness and thickness of the structure 1 are reduced. Structures 3 to 10 are structures in which a plurality of reinforcing members 20 as shown in FIG. 4 are arranged along the member longitudinal direction X of the hollow member 10, the material of the reinforcing member 20 is CFRP, and its plate thickness is Is 0.8 mm. In the structure 3, the interval between the adjacent reinforcing members 20 is random, and the interval between the reinforcing members 20 is different from each other. In the structures 4 to 8, the reinforcing members 20 are arranged in the entire region of the hollow member 10 in the member longitudinal direction X, and the intervals between the reinforcing members 20 are constant. In the structure 9, as shown in FIG. 9, the reinforcing members 20 are arranged only at the front part of the hollow member 10 in the member longitudinal direction X, and the intervals between the reinforcing members 20 are constant. In the structure 10, as shown in FIG. 10, the reinforcing members 20 are arranged in the entire region in the member longitudinal direction X of the hollow member 10, but the spacing between the reinforcing members 20 arranged in front of the hollow member 10 and the hollow member The spacing between the reinforcing members 20 arranged at the rear of the 10 is different.

構造 The structure 11 uses a steel plate as a material of the reinforcing member 20. The structure 12 is a structure in which the thickness of the reinforcing member 20 is changed to 2.8 mm. The structure 13 is a structure in which the thickness of the reinforcing member 20 is changed to 0.6 mm. The structure 14 is a structure in which the thickness of the reinforcing member 20 is changed to 3.2 mm. The structure 15 uses GFRP as a material of the reinforcing member 20. In the structure 16, the reinforcing members 20 are arranged only at the front part of the hollow member 10 in the member longitudinal direction X, and the number thereof is two.

The mechanical properties of CFRP used as the reinforcing member 20 in the structures 3 to 10, 12 to 14, and 16 are as follows.
Vf (fiber content volume ratio): 50%
Young's modulus: 102 GPa
Breaking strength: 1500 MPa
Elongation at break: 1.5%

The mechanical properties of the steel sheet used as the reinforcing member 20 in the structure 11 are as follows.
Tensile strength: 440MPa
Elongation at break: 28%
The mechanical properties of the GFRP used as the reinforcing member 20 in the structure 15 are as follows.
Vf (fiber content volume ratio): 50%
Young's modulus: 13 GPa
Breaking strength: 200MPa
Elongation at break: 3.0%

This simulation simulates a frontal collision test of an automobile, and was performed by colliding a rigid wall having a mass of 200 kg with the bumper beam 40 shown in FIGS. 1 to 3 at 12 m / s. The rear end 10b of the hollow member 10 in each analysis model is restricted. Hereinafter, simulation results will be described.

In addition, Table 1 shows the deformation mode of each analysis model as a simulation result. The “lateral bending” in the deformation mode shown in Table 1 is a deformation mode in which a horizontal bending deformation occurs from the initial deformation of the hollow member 10. The “unstable axial crush” in the deformation mode shown in Table 1 means that the crushing deformation of the hollow member 10 is irregularly present in the member longitudinal direction X, and the crushing deformation occurs from the front end 10a of the hollow member 10. This is a deformation mode that is not continuous toward the rear end 10b. “Stable axial crushing” in the deformation mode shown in Table 1 means that the crushing deformation of the hollow member 10 gradually progresses along the member longitudinal direction X, and the crushing deformation occurs continuously from the front end 10a to the rear end 10b. Mode.

FIG. 34 is a plan view showing a state in which the analysis model of the structure 1 is being deformed in the collision simulation, and FIG. 35 is a plan view showing a state after the deformation of the analysis model of the structure 1 in the collision simulation. As shown in FIGS. 34 and 35, in the structure 1 in which the reinforcing member is not provided, when a load is input, the hollow member is horizontally bent. Such a deformation of the hollow member has also occurred in the structure 2, the structure 3, the structure 11, and the structure 16.

FIG. 36 is a plan view showing a state in which the analysis model of the structure 4 is being deformed in the collision simulation, and FIG. 37 is a plan view showing a state after deformation of the analysis model of the structure 4 in the collision simulation. As shown in FIG. 36, in the initial stage of deformation of the hollow member, crushing deformation occurred not only near the front end but also near the rear end, and the deformation mode became unstable axial crushing. Further, as shown in FIG. 37, when the deformation of the hollow member further progressed, the center portion of the hollow member was horizontally bent. Such deformation of the hollow member has also occurred in the structure 5, the structure 13, and the structure 14.

38, on the other hand, FIG. 38 is a plan view showing a state in which the analysis model of the structure 7 is being deformed in the collision simulation, and FIG. 39 is a plan view showing a state after deformation of the analysis model of the structure 7 in the collision simulation. As shown in FIGS. 38 and 39, in the structure 7, the crush deformation is stably generated in the deformation process of the hollow member. When the deformation mode of the hollow member is lateral bending deformation, the plastic strain generated in the portion other than the horizontal bent portion of the hollow member is small, so the portion other than the horizontal bent portion hardly contributes to the improvement of the energy absorption performance. In the case where the deformation mode is stable axial crushing as in 7, the portion where plastic strain occurs increases, and the energy absorption performance can be improved. Such deformation of the hollow member has also occurred in Structure 6, Structures 8 to 10, Structure 12, and Structure 15.

Next, from the load-stroke diagram when the rigid body wall collided, the amount of energy absorption at the time of the 750 mm stroke of the rigid body wall was calculated, and the energy absorption performance of each analysis model was compared. The result is shown in FIG. Note that the vertical axis of the graph in FIG. 40 is the ratio between the amount of energy absorbed in each structure and the amount of energy absorbed in Structure 1.

As shown in FIG. 40, in the structures 6 to 10, the structures 12, and 15 in which the axial crushing deformation is stably generated when a load is input, the energy absorption performance is improved as compared with the structure 1. Further, as shown in Table 1 above, in the structures 6 to 10, the weight reduction ratio with respect to the structure 1 is large. Therefore, according to the result of this simulation, when the interval between the reinforcing members is within the range of 0.74 times to 1.84 times the minimum width W _min of the external dimensions of the hollow member, the weight is reduced. At the same time, it is possible to stably generate axial crush deformation and improve the energy absorption performance.

In addition, as shown in Table 1 above, in the structure 11, in addition to the horizontal bending of the hollow member, the weight reduction ratio with respect to the structure 1 was low, and the energy absorption performance was not improved. That is, in the configuration according to the present invention, it can be said that it is not preferable to use a steel plate as the material of the reinforcing member.

When the structures 12 to 14 are compared, when the plate thickness of the reinforcing member is 2.8 mm (structure 12), the deformation mode is stable axial crushing, whereas when the plate thickness of the reinforcing member is 0.6 mm. In some cases (Structure 13) or 3.2 mm (Structure 14), the deformation mode is unstable axial crush. That is, in the configuration according to the present invention, it can be said that the plate thickness of the CFRP member as the reinforcing member is preferably 0.8 mm to 2.8 mm.

構造 In the structure 15, GFRP is used as a material of the reinforcing member. In this case, the deformation mode is stable axial crush, and the energy absorption performance is improved with respect to the structure 1. That is, in the configuration according to the present invention, it can be said that the use of GFRP as the material of the reinforcing member is also effective.

構造 In the structure 16, the number of reinforcing members arranged in the hollow member is two. In this case, the deformation mode is lateral bending, and the energy absorption performance is not improved. That is, in the configuration according to the present invention, it can be said that the number of reinforcing members to be arranged is preferably three or more.

The present invention is applicable to structural members for vehicles.

1 Frame 10 Hollow member 10a Front end 10b of hollow member Rear end 11a of hollow member Top surface 11b of hollow member 11d Side surface of hollow member 11c Bottom portions 11e to 11h of hollow member Ridge line portion of hollow member 20 Reinforcement member 20a Reinforcement member Plate surfaces 21a to 21d of the reinforcing member Flange 30 of the reinforcing member Crash box 40 Bumper beam W _max Maximum width on the external dimensions of the hollow member W _min Minimum width on the external dimensions of the hollow member

Claims (7)

1. A metal hollow member,
   A plate-like reinforcing member made of FRP, each side of which is joined to an inner surface of the hollow member and a plurality of which are arranged at intervals along a member longitudinal direction of the hollow member so as to separate an inner space of the hollow member. With
   In a cross section perpendicular to the member longitudinal direction of the hollow member, the minimum width of the hollow member in external dimensions is 30% or more of the maximum width of the hollow member in external dimensions,
   Each reinforcing member has a direction in which the plate surface of the reinforcing member is perpendicular to the longitudinal direction of the hollow member, and is 0.74 times to 1. Three or more are arranged at 84 times interval,
   A structural member for a vehicle, wherein the reinforcing member has a plate thickness of 0.7 to 3.0 mm.
2. The hollow member has a bending inducing part in a part in the member longitudinal direction,
   The vehicle structural member according to claim 1, wherein an interval between the reinforcing members arranged in the bending inducing section is smaller than an interval between the reinforcing members arranged in a portion other than the bending inducing section.
3. The hollow member has a bending inducing part in a part in the member longitudinal direction,
   The structural member for a vehicle according to claim 1, wherein a thickness of the reinforcing member disposed in the bending inducing portion is larger than a thickness of the reinforcing member disposed in a portion other than the bending inducing portion.
4. The hollow member has a bending inducing part in a part in the member longitudinal direction,
   4. The reinforcing member according to claim 1, wherein a tensile strength of the reinforcing member arranged at the bending inducing portion is larger than a tensile strength of the reinforcing member arranged at a portion other than the bending inducing portion. Vehicle structural member.
5. The vehicle structural member according to any one of claims 1 to 4, wherein the FRP is CFRP or GFRP.
6. The structural member for a vehicle according to any one of claims 1 to 5, wherein the hollow member has a tensile strength of 980 MPa or more.
7. The vehicle structural member according to any one of claims 1 to 6, which is any one of a front side member, a rear side member, an extension, and a crash box.

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