JP7135275B2 - Vehicle structural member - Google Patents

Description

The present invention relates to structural members for vehicles.

In recent years, from the viewpoint of protecting the global environment, there is a demand for improving the fuel efficiency of automobiles. On the other hand, maintenance or improvement of collision safety of vehicles is required. In order to satisfy these demands, the development of high-strength and lightweight car body structures is underway. Frames, which are structural members for vehicles and form the frame of the vehicle body, are also being made stronger and thinner in the steel sheets that form the frame in order to reduce the weight of the vehicle body structure while maintaining conventional collision performance. ing.

Further, in order to suppress deformation of the frame at the time of vehicle collision, a filling member made of foamed resin material or the like is sometimes filled inside the frame. For example, Patent Literature 1 below discloses a technique in which a filling member is arranged in a cavity existing between a metal element forming a frame and a reinforcement joined to each side surface of the metal element. Patent Literature 2 listed below discloses a technique of arranging a filling member inside a frame (for example, inside corners of the frame). Patent Document 3 below discloses a technique in which a filling member is arranged between a base material provided inside a frame and the frame. Patent Document 4 listed below discloses a technique in which a filling member is arranged along the inner wall of the frame.

Japanese Patent Publication No. 2015-523269 JP 2013-67234 A Japanese Patent Application Laid-Open No. 2002-173049 JP-A-11-217084

By the way, when the above-mentioned frame is made of a metal plate (steel plate (high-strength steel plate), aluminum plate, etc.) that is stronger than before, the axial resistance of the frame when a collision occurs in the longitudinal direction of the frame, etc. The plate thickness of the frame is set so that the collision safety performance indicated by the load bearing performance is equivalent to that of a conventional frame formed of a metal plate. In this case, the plate thickness of the frame can be set thinner than the plate thickness of the conventional metal plate. Henceforth, a metal plate is described as a steel plate which is a representative material of a metal plate.

However, in the event of a collision in the longitudinal direction of a thin-walled frame, the cross-sectional deformation of the frame may occur when the frame is bent, making it impossible to ensure the expected collision safety performance of the frame. The inventors have found that there is

FIG. 42 is a cross-sectional view showing an example of a change in the cross-sectional shape of the thinned frame 100. As shown in FIG. As shown in FIG. 42, when the frame 100 is flexed when a collision occurs in the longitudinal direction of the frame 100, the bottom wall portion 100a expands in the out-of-plane direction and the side wall portion 100b bends in the out-of-plane direction. It deforms (cross-sectional shape 101). As the bending progresses further, the deformation in the out-of-plane direction of the bottom wall portion 100a and the side wall portions 100b progresses further, so that the cross-sectional shape 102 of the frame 100 is significantly deformed from the initial cross-sectional shape.

Also, FIG. 43 is a cross-sectional view showing another example of change in the cross-sectional shape of the thinned frame 200 . As shown in FIG. 43, when the frame 200 is bent in the longitudinal direction of the frame 200 or when the bottom wall portion 200a is hit, the bottom wall portion 200a is dented, and , the side wall portion 200b is deformed (cross-sectional shape 201). As the bending progresses further, the bottom wall portion 200a and the side wall portion 200b are deformed in the out-of-plane direction, so that the cross-sectional shape 202 of the frame 200 is significantly deformed from the initial cross-sectional shape. When the frame 100 (200) is deformed as shown in FIGS. 42 and 43, so-called sectional collapse occurs.

When the plate thickness of the frame becomes smaller than that of the conventional frame, the bending rigidity of the frame decreases, so that the stress generated in the frame increases due to the input of the collision load. Then, as shown in FIGS. 42 and 43, when the frame is subjected to bending deformation, out-of-plane deformation is likely to occur in each wall surface constituting the frame. Due to this cross-sectional deformation, the load-bearing performance exhibited by the bent cross-section of the frame becomes lower than that at the design stage. As a result, the conventional collision safety performance of the frame is reduced. As a result, it may not be possible to ensure the expected collision safety performance simply by reducing the weight of the vehicle body by simply using a high-strength steel plate that forms the frame.

The techniques disclosed in Patent Documents 1 to 4 are techniques that use a filling member to increase the strength of the frame and suppress bending deformation of the frame due to a collision. However, in order to further reduce the weight of the vehicle body, it is useful to further increase the mass efficiency of the load-bearing performance of the filler member and to suppress out-of-plane deformation, which is a factor in reducing the load-bearing performance of the frame. The inventors thought that it was. However, no study has been made so far on the effective arrangement of the filling member for improving the load-bearing performance of the frame and suppressing the out-of-plane deformation.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the weight of the vehicle body while maintaining high load-bearing performance in the event of a vehicle collision. To provide a new and improved structural member for a vehicle.

In order to solve the above-described problems, according to one aspect of the present invention, there is provided a bottom wall portion, a pair of side wall portions erected from both ends of the bottom wall portion, and a top wall portion facing the bottom wall portion. A hollow member forming a closed cross section by the bottom wall portion, the pair of side wall portions and the top wall portion, and a hollow member which is in close contact with the inner surface of one of the bottom wall portion or the top wall portion and on the inner surface of the other. a reinforcing member arranged so as not to be in close contact with the hollow member, the hollow member further comprising a bend-inducing portion in a part of the hollow member in the longitudinal direction, and one of the bottom wall portion and the top wall portion a contact portion arranged inside the bending induced by the bending-inducing portion and the other arranged outside the bending induced by the bending-inducing portion, the surface of the reinforcing member being in close contact with the inner surface of the hollow member; It is a remaining region other than the close contact portion, and is divided into a non-contact portion that does not adhere to the hollow member, and the non-contact portion is adjacent to the space extending in the longitudinal direction inside the hollow member without a break. The reinforcing member is a filling member, and the reinforcing member has an end face that planarly contacts the inner surface of the hollow member at the end in the circumferential direction perpendicular to the longitudinal direction of the hollow member. Alternatively, an end surface rising from the inner surface of the hollow member toward the inside of the hollow member is formed, the reinforcing member is partially arranged in the longitudinal direction of the hollow member corresponding to the bending inducing portion, and A structural member for a vehicle is provided, the entirety of which is not in close contact with the inner surface of one of the bottom wall portion and the top wall portion .

The reinforcing member may be arranged in close contact with an inner side of a ridge line portion connecting the side wall portion and the bottom wall portion or the ceiling wall portion.

The reinforcing member may be arranged in close contact with the inner surface of the side wall portion.

The reinforcing member may be arranged along the inner surface of the portion corresponding to the inner side of the bending induced by the bending inducing portion.

The bending-inducing portion may be a portion having a radius of curvature of 260 mm or less of a central axis along the longitudinal direction formed by the center of gravity of the cross section of the hollow member.

The bending-inducing portion may include a portion where the section modulus of the hollow member changes in the longitudinal direction.

The bending-inducing portion may include a portion provided with at least one of a concave portion, a convex portion, a hole portion, a plate thickness changing portion, and a thin portion.

At least one of the concave portion, the convex portion, and the plate thickness changing portion may be arranged in plurality along the longitudinal direction of the hollow member.

The bending-inducing portion may include a portion where the yield strength of the hollow member varies in the longitudinal direction.

The thickness of the metal plate forming the hollow member may be 2.3 mm or less.

The vehicle structural member is at least one of a front side member, a rear side member, a crash box, a pillar, a floor reinforcement, a floor cross member, a bumper reinforcement, a side sill, a roof side rail, a roof center reinforcement, or a tunnel. may be

According to the above configuration, since the reinforcing member is provided in close contact with the inner surface of the bottom wall portion or the top wall portion, out-of-plane deformation of the bottom wall portion or the top wall portion provided with the reinforcing member can be suppressed. As a result, out-of-plane deformation of the hollow member when a collision load is input is suppressed, so the load-bearing performance exhibited by the cross section of the hollow member can be maintained at the level assumed at the design stage. Therefore, it is possible to maintain the collision safety performance of the vehicle structural member at an expected level while suppressing an increase in the weight of the vehicle body (that is, realizing a reduction in the weight of the vehicle body).

As described above, according to the present invention, it is possible to reduce the weight of the vehicle body while maintaining high load resistance performance in the event of a vehicle collision.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an automobile for explaining application targets of a vehicle structural member according to an embodiment; 1 is a perspective view showing a schematic configuration of an example of a vehicle frame according to an embodiment of the invention; FIG. It is the schematic diagram which visualized the central axis of the hollow member which concerns on the same embodiment. It is a cross-sectional view showing a cross section orthogonal to the Z-axis direction of an example of the frame according to the same embodiment. FIG. 5 is a cross-sectional view of the frame shown in FIG. 4 taken along the VV cutting line; FIG. 5 is a cross-sectional view of the frame shown in FIG. 4 taken along the line VI-VI. FIG. 4 is a cross-sectional view of a frame for explaining a first arrangement example of filling members according to the same embodiment; FIG. 7 is a cross-sectional view of the frame for explaining a second arrangement example of the filling member according to the same embodiment; FIG. 10 is a cross-sectional view of the frame for explaining a third arrangement example of the filling member according to the same embodiment; FIG. 10 is a cross-sectional view of a frame for explaining a modification of the second arrangement example of the filling member according to the same embodiment; FIG. 11 is a cross-sectional view of a frame for explaining a modification of the third arrangement example of the filling member according to the same embodiment; FIG. 10 is a cross-sectional view of the frame for explaining a fourth arrangement example of the filling member according to the same embodiment; FIG. 4 is a cross-sectional view of a frame for explaining an example of holes provided in the hollow member according to the same embodiment; FIG. 4 is a schematic diagram showing another example of holes provided in the hollow member according to the same embodiment; FIG. 4 is a schematic diagram showing another example of holes provided in the hollow member according to the same embodiment; FIG. 4 is a schematic diagram showing another example of holes provided in the hollow member according to the same embodiment; FIG. 4 is a schematic diagram showing another example of holes provided in the hollow member according to the same embodiment; FIG. 4 is a cross-sectional view of a frame for explaining an example of bead portions provided in the hollow member according to the same embodiment; FIG. 5 is a schematic diagram showing another example of recesses provided in the hollow member according to the same embodiment. FIG. 5 is a schematic diagram showing another example of recesses provided in the hollow member according to the same embodiment. FIG. 5 is a schematic diagram showing another example of recesses provided in the hollow member according to the same embodiment. FIG. 5 is a schematic diagram showing another example of recesses provided in the hollow member according to the same embodiment. It is a schematic diagram which shows an example of the shape and size of the recessed part which concerns on the same embodiment. FIG. 5 is a schematic diagram showing another example of recesses provided in the hollow member according to the same embodiment. FIG. 10 is a cross-sectional view of a frame for explaining an example of convex portions provided on the hollow member according to the same embodiment; FIG. 10 is a schematic diagram showing another example of a convex portion provided on the hollow member according to the same embodiment; FIG. 10 is a schematic diagram showing another example of a convex portion provided on the hollow member according to the same embodiment; FIG. 10 is a schematic diagram showing another example of a convex portion provided on the hollow member according to the same embodiment; FIG. 10 is a schematic diagram showing another example of a convex portion provided on the hollow member according to the same embodiment; It is a schematic diagram which shows an example of the shape and size of the convex part which concerns on the same embodiment. FIG. 10 is a schematic diagram showing another example of a convex portion provided on the hollow member according to the same embodiment; FIG. 4 is a schematic diagram showing an example of a plate thickness changing portion provided in the hollow member according to the same embodiment; It is a schematic diagram which shows an example of the thin part provided in the hollow member which concerns on the same embodiment. FIG. 5 is a cross-sectional view of a frame for explaining an example of a different strength portion provided in the hollow member according to the same embodiment; FIG. 5 is a schematic diagram showing another example of a different strength portion provided in the hollow member according to the same embodiment. FIG. 5 is a schematic diagram showing another example of a different strength portion provided in the hollow member according to the same embodiment. FIG. 4 is a schematic diagram showing an example of a strength varying portion provided in the hollow member according to the same embodiment; FIG. 5 is a cross-sectional view of a frame for explaining an example of a combination of bent portions and hole portions provided in the hollow member according to the same embodiment; FIG. 4 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a first example of a hollow member according to another embodiment of the present invention; FIG. 10 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a second example of a hollow member according to another embodiment of the present invention; FIG. 10 is a cross-sectional view showing an arrangement example of a filling member in a bent portion according to Comparative Example 1; FIG. 5 is a cross-sectional view showing an example of a change in cross-sectional shape of a thinned frame; FIG. 8 is a cross-sectional view showing another example of change in cross-sectional shape of a thinned frame;

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

<1. Application target of vehicle structural member>
Before describing the configuration of a vehicle frame that is an example of a vehicle structural member according to an embodiment of the present invention, an application target of the vehicle structural member will be described. FIG. 1 is a schematic configuration diagram of an automobile for explaining the application target of the vehicle structural member according to the present embodiment. A vehicle body provided in a vehicle 1000 such as a general automobile shown in FIG. 1 can be classified into a front structure (FRONT), a rear structure (REAR), and a cabin structure (CABIN).

The front structure and the rear structure are also called "crushable zones", and have a function of absorbing and mitigating the impact on the vehicle (impact absorption function) by crushing themselves in the event of a vehicle collision. That is, in order to ensure the safety of passengers in the cabin in the event of a vehicle collision, the front structure and the rear structure are required to absorb as much energy as possible due to the collision (collision energy). Therefore, the frames forming the front structure and the rear structure are required to absorb a large amount of collision energy even when bending or crushing occurs at the time of collision. Frames used for the front structure and the rear structure are, for example, front side members, rear side members, bumper reinforcements, crash boxes, and the like. The front side member includes a front side member barrier forming a rear end portion and a front side member front forming a portion on the front side of the rear end portion. The rear side member includes a rear side member barrier forming a rear end portion and a rear side member front forming a portion on the front side of the rear end portion.

On the other hand, the cabin structure is also called a "safety zone" and has a function (passenger protection function) to ensure the safety of passengers on board the vehicle in the event of a vehicle collision. In other words, in order to ensure the safety of the occupants in the event of a vehicle collision, the cabin structure is required to be a structure that is resistant to crushing against the impact force. Therefore, the frame that constitutes the cabin structure is required to be resistant to deformation and have high load-bearing performance. Frames used in the cabin structure include, for example, front pillars (A pillars), center pillars (B pillars), rear pillars (C pillars, D pillars), roof pillars, side sills, roof rails, cross members, and tunnels.

By the way, in order to achieve both the maintenance of collision safety and weight reduction of vehicles, steel sheets forming the vehicle body structure are being strengthened and thinned. The frames constituting the front structure, the rear structure, and the cabin structure are also being replaced with thin, high-strength steel plates. Specifically, the thickness of the frame made of high-strength steel plate is set to be greater than that of the conventional steel plate so that at least one of the amount of collision energy absorption and load bearing performance is equivalent to that of the frame made of conventional steel plate. It is set smaller than the frame to be formed. As a result, the weight of the frame can be reduced while maintaining the collision performance of the high-strength frame equivalent to that of the conventional frame.

However, as shown in FIGS. 42 and 43, the present inventors have clarified that when bending deformation occurs in a thinned frame, the cross section of the frame is deformed by the following mechanism. Specifically, (1) when a collision load is input to the frame, the bottom wall portion 100a corresponding to the inner side of the bend undergoes out-of-plane deformation. (2) Out-of-plane deformation of the bottom wall portion 100a causes out-of-plane deformation of the side wall portion 100b, and local plastic deformation occurs at the ridge line connecting the bottom wall portion 100a and the side wall portion 100b. After that, (3) the side wall portion 100b collapses in the out-of-plane direction. As a result, the cross section of the frame is deformed, and so-called cross-sectional collapse may occur in the frame. If this cross-sectional collapse occurs, the collision safety performance exhibited by the frame cross-section will be lower than that at the design stage, so that the conventional collision safety performance of the frame will be reduced. In other words, simply reducing the weight of the frame that makes up the vehicle body will result in the collision energy absorption characteristics expected of the front and rear structures, and the load bearing performance expected of the cabin structure, to be lower than those assumed at the time of design. will also be lower.

In order to maintain the expected level of collision safety performance while reducing the weight of the vehicle by thinning the frame, it is important to suppress the cross-sectional deformation of the frame as described above. The inventors of the present invention thought that expected collision safety performance could be exhibited if cross-sectional deformation of the frame due to the collision load could be suppressed.

The inventors diligently studied methods for maintaining high collision safety performance of the frame. As a result, the present inventors have found that it is effective to suppress out-of-plane deformation of the bottom wall portion or the top wall portion of the frame in order to maintain high load bearing performance of the frame against the input of collision load. Found it. Therefore, the present inventors have conceived of arranging a filling member or the like having a significantly lower mass density than the steel plate on the inner surface of the bottom wall portion or the top wall portion. As a result, when a collision load is applied to the frame, the filler member suppresses cross-sectional deformation of the frame, so that the load-bearing performance can be maintained at a high level without significantly increasing the weight of the frame. They pondered. A structural member for a vehicle according to an embodiment of the present invention, which can maintain a high load-bearing performance of the frame and realize a lightweight vehicle body, will be described below.

<2. Configuration of Vehicle Frame>
(frame component)
FIG. 2 is a perspective view showing a schematic configuration of an example of the vehicle frame 1 according to one embodiment of the invention. Note that the vehicle frame 1 in this specification is an example of a vehicle structural member, and is hereinafter simply referred to as the frame 1 . The vehicle structural members include, for example, front side members, rear side members, crash boxes, pillars, floor reinforcements, floor cross members, bumper reinforcements, side sills, roof side rails, roof center reinforcements, etc. and tunnels, etc. The vehicle frame 1 according to the present embodiment is preferably applied to members relating to the cabin structure, but it is also possible to apply the vehicle frame 1 to members relating to the front structure and the rear structure. Further, the vehicle structural member can be applied not only to automobiles but also to other vehicles and self-propelled machines. Other vehicles and self-propelled machines include, for example, two-wheeled vehicles, large vehicles such as buses or tractors, trailers, railroad vehicles, construction machinery, mining machinery, agricultural machinery, general machinery, and ships.

The frame 1 according to this embodiment comprises a first structural member 2, a second structural member 3 and filler members 4 (4A, 4B). A hollow member 10 according to this embodiment is formed by a first structural member 2 and a second structural member 3 .

The first structural member 2 according to this embodiment is an example of a structural member that forms an elongated hollow member, and has a hat-shaped cross section. As shown in FIG. 2, the first structural member 2 includes a bottom wall portion 2a, side wall portions 2b, 2b, flange portions 2c, 2c, and ridge portions 2d, 2d, 2e extending in the longitudinal direction (substantially in the Y-axis direction). , 2e.

The side wall portions 2b are provided to stand up from both ends of the bottom wall portion 2a in the Z-axis direction (width direction). The side wall 2b and the bottom wall 2a are often provided at an angle substantially perpendicular to each other from the viewpoint of collision performance, but the angle formed by the side wall 2b and the bottom wall 2a is limited to a substantially vertical angle. It is appropriately set according to the design of the sliding member. Moreover, the ridgeline portion 2d is a portion that serves as a boundary between the bottom wall portion 2a and the side wall portion 2b.

The flange portion 2c is provided so as to stand outward along the Z-axis direction from the end portion of the side wall portion 2b opposite to the bottom wall portion 2a. The flange portion 2c is often provided at an angle substantially perpendicular to the side wall portion 2b. determined as appropriate. Moreover, the ridgeline portion 2e is a portion that becomes a boundary between the side wall portion 2b and the flange portion 2c.

The second structural member 3 according to this embodiment is an example of a structural member forming the hollow member together with the first structural member 2, and is a plate-like member. As shown in FIG. 2, the second structural member 3 has a top wall portion 3a and joint portions 3c, 3c.

The top wall portion 3 a is a portion facing the bottom wall portion 2 a of the first structural member 2 . The joint portion 3c is a portion that abuts against the flange portion 2c of the first structural member 2 and is joined to the flange portion 2c. In other words, the ceiling wall portion 3a is a portion corresponding to a region existing between portions of the second structural member 3 that are connected to the pair of ridgeline portions 2e. The joint portion 3c is a portion that abuts on the area of the flange portion 2c sandwiched between the edge portion 2e of the second structural member 3 and the end portion of the flange portion 2c.

The hollow member 10 according to this embodiment is formed by the first structural member 2 and the second structural member 3 by joining the flange portion 2c and the joint portion 3c. At this time, as shown in FIG. 2, the hollow member 10 has a closed cross section. This closed cross section is formed by a bottom wall portion 2a, a pair of side wall portions 2b, 2b, and a top wall portion 3a. In addition, the joining method of the flange part 2c and the joining part 3c is not specifically limited. For example, the joining method may be welding, riveting, bolting, or the like. In this embodiment, the flange portion 2c and the joint portion 3c are joined by spot welding.

The shape of the closed cross section of the hollow member 10 is substantially polygonal. Here, a substantially polygon means a closed plane figure that can be approximated by a plurality of line segments. For example, the closed cross section shown in FIG. 2 is a substantially quadrilateral consisting of four line segments (corresponding to the bottom wall portion 2a, the side wall portion 2b, and the ceiling wall portion 3a) and four vertices (corresponding to the ridge portions 2d and 2e). be. This substantially quadrilateral includes rectangles, trapezoids, and the like.

Further, even if the shape of the closed cross-section of the hollow member 10 according to the embodiment of the present invention is a substantially polygonal shape other than a substantially square shape, in this specification, the hollow member 10 is defined as the bottom wall portion 2a. , a pair of side wall portions 2b, 2b and a ceiling wall portion 3a. An example of the shape of the closed cross section of the hollow member 10 will be described later.

The first structural member 2 and the second structural member 3 according to this embodiment are preferably made of metal plates such as steel plates. From the viewpoint of collision performance, the plate thickness of both structural members is preferably 2.3 mm or less for frame structures that are often used in large vehicles such as buses, and 1.3 mm for monocoque structure vehicles that are often used in normal size vehicles. It is preferably 8 mm or less, and preferably 1.4 mm or less for small vehicles such as motorcycles. If the plate thicknesses of both structural members are greater than the above-described plate thicknesses, out-of-plane deformation of the structural members at the bent portion of the hollow member 10 due to the input of the collision load is less likely to occur, so the effect obtained by the present invention is small. . Also, if the plate thickness of both structural members is greater than the plate thickness shown above, it is difficult to achieve a lightweight frame. Moreover, the strength of the first structural member 2 and the second structural member 3 according to this embodiment is not particularly limited. However, it is preferred that both structural members have a tensile strength of 780 MPa or greater to compensate for the overall strength of the frame that may be reduced due to weight reduction. Moreover, it is more preferable that the tensile strength of both structural members is 980 MPa or more.

In the case of using a steel plate with high tensile strength (so-called high-tensile steel) as each structural member for weight reduction, if the thickness of the steel plate is reduced, the tensile strength of the steel plate cannot be secured as before. Also, the bending stiffness (bending rigidity) of the steel sheet is lowered. Therefore, out-of-plane deformation can easily occur in a thin structural member.

The frame 1 according to this embodiment can compensate for the flexural rigidity of each thin structural member. Such an effect becomes even more apparent when a steel sheet having a tensile strength of 780 MPa or more is used, at which point the reduction in flexural rigidity becomes apparent. In particular, when a steel plate having a tensile strength of 980 MPa or more is used, the above-described effects become more pronounced.

The filling member 4 according to this embodiment is an example of a reinforcing member. The filling member 4 according to this embodiment is a hard foam filling member made of foamed resin material, for example. More specifically, the filling member 4 is a filling member that hardens due to chemical change after being placed inside the hollow member 10 . Therefore, the weight per unit volume of the filling member 4 is significantly lower than the weight per unit volume of the steel plate forming the hollow member 10 . The filling member 4 is made of polyurethane, for example. Also, a member made of a resin other than polyurethane may be used as the filling member 4 .

Further, as shown in FIG. 2, the hollow member 10 according to the present embodiment may be provided with bending portions 5A and 5B. The bending portion 5 is a portion where the hollow member 10 bends. That is, the bent portion 5 is a portion having a curvature radius of 260 mm or less in the longitudinal direction of the central axis formed by the center of gravity of the cross section of the hollow member 10 . FIG. 3 is a schematic diagram visualizing the central axis of the hollow member 10. As shown in FIG. As shown in FIG. 3, the central axis C1 of the hollow member 10 is bent at bent portions 5A and 5B.

Such a bending portion 5 is an example of a bending inducing portion. The hollow member 10 having such a bent portion 5 is obtained, for example, by performing press molding so that the bent portion 5 is provided in the first structural member 2 and the second structural member 3, and assembling these structural members. be done. The bent portion 5 is appropriately provided according to the structure of the vehicle to which the frame 1 is applied. The number of bent portions 5 provided in the hollow member 10 is not particularly limited, and is appropriately determined according to the structure of the vehicle as described above.

When the hollow member 10 is formed with a bend-inducing portion, a collision in the longitudinal direction causes bending deformation in the bending-inducing portion. For example, as shown in FIG. 3, if at least one of the curvature radii RA and RB of the bent portions 5A and 5B is 260 mm or less, the hollow member 10 satisfies the curvature radius condition when a collision load is input. Bending deformation occurs in at least one of the bent portions 5A and 5B. The energy required for this bending deformation is supplied from the energy due to the collision. That is, the bending deformation of the hollow member 10 can absorb the collision energy. By providing the hollow member 10 with this bend-inducing portion, it is possible to set the bending start point of the hollow member 10 caused by collision. Therefore, it is possible to avoid an impact on the cabin structure due to unexpected bending of the hollow member 10, so that it is possible to ensure the safety of the occupants in the cabin.

In addition, the bend inducing portion is not limited to the example of the bending portion 5 described above. For example, a hollow member that does not have a bent portion (for example, includes a hollow member that extends substantially linearly in the longitudinal direction) is provided with a hole, a bead, a convex, a thin portion, a different strength portion, and the like. A portion functions as a bending inducer. The portion provided with any one of the hole portion, the bead portion, the convex portion, and the thin portion is a portion where the section modulus of the hollow member 10 changes locally in the longitudinal direction of the hollow member 10 . At the portion where the section modulus locally changes, the bending stress generated in the hollow member 10 due to the same bending moment locally changes, so bending of the hollow member 10 is induced at that portion. More specifically, in a portion of the hollow member 10 where the section modulus is locally small, bending stress is increased at that portion, so bending occurs at that portion. In addition, in a portion of the hollow member 10 where the section modulus is locally large, the section modulus of the portion including the front and rear regions of the hollow member 10 in the longitudinal direction of the portion is relatively small. Therefore, bending occurs at the boundary portion between the region and the portion having a locally large section modulus.

Also, the different strength portion is a portion where the strength of the hollow member locally changes in the longitudinal direction of the hollow member 10 . Plastic deformation of the hollow member 10 is induced in the portion where the strength locally changes. For example, at a portion of the hollow member 10 where the strength is locally low, plastic deformation occurs first in the hollow member 10, so bending occurs at that portion. In addition, in the portion of the hollow member 10 where the strength is locally high, the strength of the portion including the front and rear regions of the hollow member 10 in the longitudinal direction of the portion is relatively small. Therefore, bending occurs at the boundary portion between the region and the portion with locally high strength.

In addition, in the hollow member having a bent portion, a portion for inducing bending, such as the hole portion shown in the above example, may be further provided on the bending inner portion of the bent portion. Thereby, the hollow member 10 can be bent more reliably at the bent portion. Further, by combining a plurality of examples of bending induction shown above, bending of the hollow member 10 at the bending induction portion can be caused more reliably.

For example, the frame 1 used for the cabin structure such as the center pillar is required to have resistance to deformation as described above. Therefore, it is not preferable to provide the hollow member 10 with a bend-inducing portion such as the bent portion 5 . In this case, the hollow member 10 is not provided with bending inducers. Further, even in the case of the frame 1 used for the cabin structure, due to the design or processing of the vehicle body, the hollow member 10 may have a fragile portion that induces bending of the frame 1, such as the bent portion or the hole portion described above. sometimes.

As described above, the filling member 4 according to the embodiment of the present invention maintains load-bearing performance even for the hollow member 10 that is not provided with a bend-inducing portion and the hollow member 10 that has a weak portion. can be obtained. Of course, it is possible to obtain the effect of maintaining the load bearing performance of the filling member 4 according to the present embodiment even for the hollow member 10 provided with the bending induction portion. In this specification, a hollow member 10 provided with a bent portion 5 as shown in FIG. .

The length of the bottom wall portion 2a in the Z-axis direction is preferably equal to or greater than the length of the side wall portion 2b in the X-axis direction. As a result, the geometrical moment of inertia of the hollow member 10 in the Z-axis direction becomes larger than the geometrical moment of inertia in the X-axis direction. Therefore, when a collision load is input to the hollow member 10, the bottom wall portion 2a and the top wall portion 3a are likely to bend. Therefore, by arranging the filling member 4 on the bottom wall portion 2a and the top wall portion 3a, it is possible to sufficiently improve the load bearing performance.

(Arrangement of filling member)
FIG. 4 is a cross-sectional view showing a cross section orthogonal to the Z-axis direction of an example of the frame 1 according to this embodiment. As shown in FIG. 4, the hollow member 10 is provided with a bent portion 5A in which the bottom wall portion 2a is bent inward, and a bent portion 5B in which the top wall portion 3a is bent inward. ing. As shown in FIGS. 2 and 4, the filling members 4A and 4B according to the present embodiment are arranged in close contact with the inner surfaces of the portions of the side wall portion 2b where the bent portions 5A and 5B are provided. These bent portions 5 correspond to weak portions in the frame 1 .

The definitions of the symbols for the dimensions attached to the frame 1 shown in FIG. 4 are as follows.
L _FL : Length of the hollow member 10 in the Y-axis direction (longitudinal direction).
D _FL1 : Cross-sectional dimension in the X-axis direction at the collision-side end of the hollow member 10 .
D _FL2 : Cross-sectional dimension in the X-axis direction at the other end of the hollow member 10 .
S _FL : the offset length of the second structural member 3 before and after the bend 5 in the longitudinal direction.
L _FMA , L _FMB : Y-axis length of filling members 4A and 4B.

FIG. 5 is a sectional view of the frame 1 shown in FIG. 4 taken along the line VV. 6 is a cross-sectional view of the frame 1 taken along line VI--VI shown in FIG. As shown in FIG. 5, the filling member 4A is arranged in close contact (preferably adhered) to the inner surface of the bottom wall portion 2a. The inner surface of the bottom wall portion 2a corresponds to the bending inner portion of the bent portion 5A. In particular, as shown in FIG. 5, the filling member 4A is arranged in close contact with the inner surface of the central portion of the bottom wall portion 2a. Further, as shown in FIG. 6, the filling member 4B is arranged in close contact with the inner surface of the ceiling wall portion 3a. The inner surface of the top wall portion 3a corresponds to the inner portion of the bending portion 5B.

With this arrangement, when a force in the out-of-plane direction due to bending compression of the frame 1 is applied to the bottom wall portion 2a, deformation of the central portion of the bottom wall portion 2a is restrained by the filling member 4A. Thereby, the out-of-plane deformation of the bottom wall portion 2a can be suppressed. That is, when a collision load is applied to the frame 1, out-of-plane deformation of the hollow member at the portion where the filling member 4A is arranged can be suppressed. As a result, cross-sectional deformation of the frame 1 is suppressed, so that the load-bearing performance of the frame 1 can be enhanced. Therefore, while reducing the weight of the frame 1, high collision safety performance can be maintained.

The thickness a of the filling member 4</b>A in the X-axis direction is not particularly limited, and the thickness a is appropriately set according to the load-bearing performance and weight required of the frame 1 . For example, a plate member such as a reinforcement (not shown) may be provided inside the hollow member 10 in order to control the thickness a of the filling member 4A. Further, the distances _b1 and b2 from the side wall portion that determine the arrangement position of the filling member 4A _are not particularly limited. However, by arranging the filling member 4A in close contact with the inner surface of the central portion of the bottom wall portion 2a, the out-of-plane deformation of the bottom wall portion 2a can be efficiently suppressed. Therefore, the distances _b1 and b2 _are preferably the same. Also, the magnitudes of the distances b1 and b2 are determined according to the thickness of the filling member 4A in the Z-axis direction, which is appropriately set according to the load bearing performance and weight required of the frame _{1. FIG} .

In the present invention, close contact means that they are arranged in contact with each other without gaps. In particular, among close contact, adhesion that constrains each other is most preferable. Even if they are not constrained to each other, the filling member 4 exhibits the effect of suppressing out-of-plane deformation of at least one of the walls forming the hollow member 10 . For example, it is assumed that the frame 1 according to this embodiment changes in cross-sectional shape as shown in FIGS. 42 and 43 . When the filling member 4 is adhered to the inner surface of at least one of the bottom wall portion 2a and the top wall portion 3a, when the bottom wall portion 2a or the top wall portion 3a is deformed out of plane, the filling member 4 is also out of the plane of the inner surface. Follow deformation. Therefore, the effect of suppressing out-of-plane deformation of the bottom wall portion 2a or the top wall portion 3a by the filling member 4 is remarkably exhibited. Further, when the filling member 4 and the inner surface of at least one of the bottom wall portion 2a and the top wall portion 3a are arranged in close contact without restraining each other, if the bottom wall portion 2a or the top wall portion 3a is deformed out of plane, , the filling member 4 and the inner surface may be partially separated. However, even when the inner surface is deformed out of plane, it is in contact with at least part of the filling member 4 . Therefore, even when the filling member 4 and the inner surface are in close contact with each other without restraining each other, the effect of suppressing the out-of-plane deformation of the bottom wall portion 2a or the top wall portion 3a by the filling member 4 is sufficiently exhibited. .

The arrangement of the filling member 4A and the action and effect of the arrangement have been described above. The action and effect described above are similarly exhibited by the filling member 4B disposed inside the bent portion 5B as shown in FIG.

As described above, in the frame 1 according to the present embodiment, the filling member 4A is arranged in close contact with the inner surface of the bottom wall portion 2a included inside the bending portion 5, which is the bending inducing portion, and the filling member 4A is arranged inside the bending portion 5B. A filling member 4B is arranged in close contact with the inner surface of the included top wall portion 3a. With such a configuration, when a collision load is applied to the frame 1, out-of-plane deformation of the bottom wall portion 2a and the top wall portion 3a caused by bending compression of the frame 1 can be suppressed. As a result, it is possible to suppress the cross-sectional collapse of the frame 1 due to collision. Therefore, even when the thickness of the hollow member 10 is reduced in order to reduce the weight of the vehicle body, the weight of the frame 1 is not significantly increased by arranging the filling member 4 having a low mass density in the above-described portion. The load bearing performance of the frame 1 can be maintained at a high level. That is, for example, it is possible to prevent the frame 1 from easily bending at the fragile portion.

<3. Arrangement example of filling member>
The arrangement of the filling members 4A and 4B according to the present embodiment has been described above. Note that the arrangement of the filling member 4 is not limited to the examples shown in FIGS. Another arrangement example of the filling member 4 will be described below.

(First arrangement example)
FIG. 7 is a cross-sectional view of the frame 1 for explaining a first arrangement example of the filling member according to this embodiment. 7 corresponds to the cross section of the frame 1 taken along the line VV of the frame 1 shown in FIG.

As shown in FIG. 7, the filling member 40 according to this arrangement example is arranged so as to be continuously in close contact (preferably adhered) to the side wall portion 2b and the bottom wall portion 2a. That is, the filling member 40 is arranged in close contact with the inner side of the ridgeline portion 2d. When a collision load is input to the frame 1 and bending occurs at the bent portion 5, plastic deformation occurs locally at the ridgeline portion 2d. This plastic deformation promotes the out-of-plane tilting of the side wall portion 2b. Therefore, by arranging the filling member 40 in close contact with such a position, it is possible to suppress local plastic deformation that occurs in the ridgeline portion 2d. As a result, it is possible to prevent the side wall portion 2b from tilting in the out-of-plane direction. Therefore, cross-sectional deformation of the frame 1 can be suppressed more effectively.

The thickness a of the filling member 40 is appropriately set according to the load bearing performance and weight required of the frame 1 .

7 can be similarly applied to the cross section of the frame 1 taken along the line VI-VI of the frame 1 shown in FIG. In this case, the filling member 40 is arranged in close contact with the inner surface of the ceiling wall portion 3a and the inner side of the ridgeline portion 2e.

(Second arrangement example)
FIG. 8 is a cross-sectional view of the frame 1 for explaining a second arrangement example of the filling member according to this embodiment. 8 corresponds to the cross section of the frame 1 taken along the line VV of the frame 1 shown in FIG.

The filling members 41a and 41b according to this arrangement example are arranged locally in close contact (preferably adhered) inside each of the ridge line portions 2d. With such arrangement, it is possible to suppress local plastic deformation that occurs in the ridgeline portion 2e. As a result, tilting of the side wall portion 2b in the out-of-plane direction can be reduced. Therefore, cross-sectional deformation of the frame 1 can be suppressed. In addition, in the example shown in FIG. 8, since the filling members 41a and 41b are arranged in close contact with the inside of the ridge line 2d, the cross-sectional deformation of the frame 1 can be minimized without increasing the weight of the frame 1. can be suppressed.

(Third arrangement example)
Further, the filling member according to the present embodiment may be placed in close contact (preferably by adhesion) locally on the inner side of at least one of the ridges 2d. FIG. 9 is a cross-sectional view of the frame 1 for explaining a third arrangement example of the filling member according to this embodiment. The cross-sectional view shown in FIG. 9 corresponds to the cross-section of the frame 1 taken along the line VV of the frame 1 shown in FIG.

As shown in FIG. 9, the filling member 41c according to this arrangement example is arranged in close contact with one inner side of the ridgeline portion 2d. As a result, local plastic deformation that occurs at the ridgeline portion 2d where the filling member 41c is arranged can be suppressed. Also, since the amount of the filling member to be filled can be reduced, the weight of the frame 1 can be kept from increasing.

According to the arrangement examples of the filling members shown in FIGS. 8 and 9, not only out-of-plane deformation of the bottom wall portion 2a but also local plastic deformation of the ridge line portion 2d can be suppressed. It should be noted that it is preferable to determine whether the filling member is provided inside one or both of the ridge line portions 2d according to the collision safety performance and weight required of the frame 1. FIG. Further, the thickness a (a ₁ , a ₂ ) in the Z-axis direction and the thickness c (c ₁ , c ₂ ) in the X-axis direction of the filling members 41a, 41b and 41c are appropriately set.

Alternatively, the filling member may be separately arranged in close contact with the inner surface of the central portion of the bottom wall portion 2a and the inner side of the ridge line portion 2d. If each of the filling members is arranged in close contact with the inner surface of the central portion of the bottom wall portion 2a and the inner side of the ridge line portion 2d, the effect of suppressing cross-sectional deformation of the frame 1 can be sufficiently obtained.

8 and 9 can be similarly applied to the cross section of the frame 1 taken along the line VI-VI of the frame 1 shown in FIG. In this case, the filling members 41a to 41c are arranged in close contact with the inside of the ridgeline portion 2e.

Further, the filling member may be arranged in close contact with the inner surface of the side wall portion 2b, not only inside the ridge line portion 2d. 10 and 11 are cross-sectional views of the frame 1 for explaining modifications of the second arrangement example and the third arrangement example of the filling member according to this embodiment. As shown in FIGS. 10 and 11, the filling members 42a, 42b and 42c may be arranged in close contact with the inner surface of the side wall portion 2b as well as inside the ridge portion 2d. Further, the filling members 42a, 42b and 42c may be arranged in close contact with the inner side of the ridgeline portion 2e. As a result, the load bearing performance of the frame 1 can be made equal to or higher than that of the arrangement examples shown in FIGS. 8 and 9 . The thickness a (a ₁ , a ₂ ) of the filling members 42 a , 42 b and 42 c is appropriately set according to the load bearing performance and weight required of the frame 1 .

(Fourth arrangement example)
FIG. 12 is a cross-sectional view of the frame 1 for explaining a fourth arrangement example of the filling member according to this embodiment. 12 corresponds to the cross section of the frame 1 taken along the line VV of the frame 1 shown in FIG.

As shown in FIG. 12, the filling member 43 according to this arrangement example is arranged in close contact (preferably, adhesion) continuously to the inner surfaces of the bottom wall portion 2a and the pair of side wall portions 2b. The side wall portion 2b is likely to collapse in the out-of-plane direction due to the bending of the frame 1 . According to the arrangement shown in FIG. 12, since the filling member 43 is also arranged in close contact with the inner surface of the side wall portion 2b, the filling member 43 can suppress out-of-plane deformation of the side wall portion 2b. Even if the frame 1 is bent, the filling member 43 prevents the side wall portion 2b from collapsing in the out-of-plane direction, thereby suppressing the cross-sectional deformation of the frame 1 and absorbing the collision energy due to the crushing of the frame 1. be able to. In other words, not only the load bearing performance of the frame 1 but also the collision energy absorption characteristics of the frame 1 can be improved.

In addition, although the filling member 43 shown in FIG. 12 is arranged continuously in close contact with the pair of side wall portions 2b and the bottom wall portion 2a, the present invention is not limited to such an example. For example, the filling members 43 may be separately arranged in intimate contact with the inner surfaces of the pair of side wall portions 2b and the bottom wall portion 2a. Further, the filling member 43 may be arranged in continuous contact with either one of the pair of side wall portions 2b and the bottom wall portion 2a. That is, the filling member 43 may be provided in an L shape in a cross section orthogonal to the Y-axis direction. That is, if the filling member 43 is provided on either one of the pair of side wall portions 2b and the bottom wall portion 2a, it is possible to improve not only the load bearing performance of the frame 1 but also the collision energy absorption characteristics of the frame 1. can. The placement position and filling amount of the filling member can be appropriately set according to the collision safety performance and weight required for the frame 1 . Also, the thicknesses a ₁ , a ₂ and a ₃ of the filling member 43 shown in FIG. 12 can be set as appropriate.

12 can be similarly applied to the cross section of the frame 1 taken along the line VI-VI of the frame 1 shown in FIG. In this case, the filling member 43 is arranged continuously in close contact with the pair of the side wall portion 2b and the ceiling wall portion 3a.

5 to 12, the filling member according to the present embodiment is arranged in a frame formed of a hollow member that does not have a bend-inducing portion realized by a bent portion, a hole portion, or the like, or a fragile portion. It can also be applied to For example, if the frame 1 shown in FIG. 2 is not provided with bent portions, the filling member 4 may be provided along the longitudinal direction of the hollow member 10 on the bottom wall portion 2a and the top wall portion 3a of the hollow member 10. . As a result, even if the frame 1 is bent such that the bottom wall portion 2a or the top wall portion 3a is bent inward at the time of collision, the cross-sectional deformation of the frame 1 can be suppressed. That is, by arranging the filling member 4 in close contact with the inner surface of the hollow member 10 corresponding to the direction in which it is desirable not to bend, it is possible to suppress bending of the frame 1 at least in that direction.

<4. Example of bending induction section>
Next, an example of a bend inducing portion provided in the hollow member 10 will be described. Although the bending portion 5 that is the bending inducing portion has been described in the above embodiment, the present invention is not limited to such an example. For example, a hollow member that does not have a bent portion (for example, includes a hollow member that extends substantially linearly in the longitudinal direction) is provided with a hole, a recess, a protrusion, a plate thickness change portion, a different strength portion, and the like. This portion realizes a function as a bending inducing portion. The portion provided with any one of the hole portion, the recessed portion, the convex portion, and the plate thickness change portion is the portion where the section modulus of the hollow member 10 changes in the longitudinal direction of the hollow member 10 . At the portion where the section modulus changes in the longitudinal direction of the hollow member 10, the bending stress generated in the hollow member 10 changes due to the same bending moment, so bending of the hollow member 10 is induced at that portion. More specifically, a portion of the hollow member 10 in the longitudinal direction where the section modulus is relatively small has a relatively large bending stress, so bending occurs in that portion. In addition, in a portion of the hollow member 10 in the longitudinal direction where the section modulus is relatively large, the section modulus of the portion including the front and rear regions of the hollow member 10 in the longitudinal direction is relatively small. Therefore, bending occurs at the boundary portion between the region and the portion having a relatively large section modulus.

Also, the different strength portion is a portion where the yield strength of the hollow member 10 changes in the longitudinal direction of the hollow member 10 . At the portion where the yield strength changes in the longitudinal direction of the hollow member 10, plastic deformation of the hollow member 10 is induced at that portion. For example, at a portion of the hollow member 10 where the yield strength is relatively low in the longitudinal direction, plastic deformation at that portion occurs first in the hollow member 10, and bending occurs at that portion. In addition, in the portion of the hollow member 10 in the longitudinal direction where the yield strength is relatively high, the yield strength of the portion including the front and rear regions of the hollow member 10 in the longitudinal direction is relatively small. Therefore, bending occurs at the boundary portion between the region and the portion where the yield strength is relatively high.

A specific example of the bending induction portion provided in the hollow member 10 will be described below.

(Hole)
FIG. 13 is a cross-sectional view of the frame 1 for explaining an example of holes provided in the hollow member according to this embodiment. As shown in FIG. 13, a hole portion 50 is provided in the bottom wall portion 2a. The section modulus of the hollow member 10 at the portion where the hole portion 50 is provided is lower than the section modulus of the hollow member 10 at portions before and after the portion where the hole portion 50 is provided (in the longitudinal direction of the hollow member 10). Therefore, when the collision load F shown in FIG. 13 is input to the hollow member 10, the frame 1 bends at the portion where the hole 50 is provided so that the hole 50 is on the inside of the bend. That is, in the longitudinal direction of the hollow member 10 , the portion of the hollow member 10 where the hole portion 50 is provided serves as the bend-inducing portion provided in the hollow member 10 .

Therefore, the filling member 4 is arranged in close contact with the inner surface of the side wall portion 2b at least at the portion where the hole portion 50 is provided. As a result, even when bending occurs in the vicinity of the hole portion 50 due to the input of the collision load F, the out-of-plane deformation of the frame 1 can be suppressed, and the load-bearing performance of the frame 1 can be maintained at a high level.

Moreover, the shape and arrangement of the holes are not limited to the examples described above. 14 to 17 are schematic diagrams showing other examples of holes provided in the hollow member according to this embodiment. As shown in FIG. 14, a circular hole 50a may be provided in the bottom wall 2a. Also, as shown in FIG. 15, a plurality of holes 50b may be provided in the bottom wall portion 2a. In this case, for example, a plurality of holes 50b may be provided side by side in a direction crossing the longitudinal direction of the hollow member 10A. In this case, when a collision load is input, the hollow member 10A is easily bent toward the bottom wall portion 2a with the hole portion 50b as the starting point of bending.

Further, as shown in FIG. 16, a hole portion 50c extending in a direction transverse to the longitudinal direction of the hollow member 10A may be provided in the bottom wall portion 2a. In this case, when a collision load is input, the hollow member 10A is bent toward the bottom wall portion 2a with the hole portion 50c as the starting point of bending. The shape of the hole portion 50c is not limited to the rounded rectangle shown in FIG. 16, and may be any shape.

Note that the direction transverse to the longitudinal direction of the hollow member 10A described above is not limited to the direction orthogonal to the longitudinal direction of the hollow member 10A as shown in FIGS. 14 to 16. FIG. For example, it is preferable that the angle between the longitudinal direction of the hollow member 10A and the crossing direction be 45 degrees or more and 90 degrees or less on the surface of the portion where the holes 50 are provided. Thereby, stable bending deformation can be induced.

Further, the portion where the hole portion 50 is provided is not limited to the bottom wall portion 2a. For example, the hole portion 50 may be provided in the side wall portion 2b or the ceiling wall portion 3a. Moreover, it is preferable that the hole portion 50 or the like is not provided in a portion facing the portion in which the hole portion 50 is provided. For example, when the hole portion 50 is provided in the bottom wall portion 2a, it is preferable that the top wall portion 3a is not provided with a portion that induces bending deformation of the other hole portion 50. FIG. This is to induce bending deformation on the side where the hole portion 50 is provided when a collision load is input.

Further, as shown in FIG. 17, a hole portion 50d may be provided in the ridgeline portion 2d. As a result, the section modulus of the portion of the hollow member 10A provided with the hole 50d in the longitudinal direction is significantly reduced, so that the bending deformation with the portion provided with the hole 50d as the starting point of bending is more reliably induced. can do.

(recess)
FIG. 18 is a cross-sectional view of the frame 1 for explaining an example of bead portions provided in the hollow member according to this embodiment. Note that the bead portion 51 is an example of the recess in this embodiment. As shown in FIG. 18, a bead portion 51 is provided on the bottom wall portion 2a. The section modulus of the hollow member 10 at the portion where the bead portion 51 is provided is lower than the section modulus of the hollow member 10 at the portions before and after the portion where the bead portion 51 is provided (in the longitudinal direction of the hollow member 10). Therefore, when the collision load F shown in FIG. 18 is input to the hollow member 10, the frame 1 bends at the portion where the bead portion 51 is provided so that the bead portion 51 is bent inside. That is, in the longitudinal direction of the hollow member 10 , the portion of the hollow member 10 where the bead portion 51 is provided serves as the bend-inducing portion provided in the hollow member 10 .

Therefore, the filling member 4 is arranged in close contact with the inner surface of the side wall portion 2b at least at the portion where the bead portion 51 is provided. As a result, when the collision load F is input and bending occurs in the vicinity of the bead portion 51, the out-of-plane deformation of the frame 1 can be suppressed, and the load-bearing performance of the frame 1 can be maintained at a high level.

Note that the shape and arrangement of the recesses are not limited to the examples described above. 19 to 22 are schematic diagrams showing other examples of recesses provided in the hollow member according to this embodiment. The term "concave portion" as used herein means a concave portion, such as an emboss or bead, provided in the bottom wall portion 2a of the hollow member 10B or the like. As shown in FIG. 19, a circular recess 51a may be provided in the bottom wall portion 2a.

Also, as shown in FIG. 20, a plurality of recesses 51b may be provided in the bottom wall portion 2a. In this case, for example, a plurality of recesses 51b may be provided side by side in a direction crossing the longitudinal direction of the hollow member 10B. In this case, when a collision load is input, the hollow member 10B is likely to be bent toward the bottom wall portion 2a with the plurality of concave portions 51b serving as bending starting points.

Further, as shown in FIG. 21, a bead portion 51c extending in a direction transverse to the longitudinal direction of the hollow member 10B may be provided on the bottom wall portion 2a. In this case, when a collision load is input, the hollow member 10B is bent toward the bottom wall portion 2a with the bead portion 51c as a starting point of bending. The shape of the bead portion 51c is not limited to the rounded rectangle shown in FIG. 21, and may be any shape.

The direction crossing the longitudinal direction of the hollow member 10B described above is not limited to the direction orthogonal to the longitudinal direction of the hollow member 10B as shown in FIG. For example, the angle formed by the longitudinal direction of the hollow member 10B and the transverse direction on the surface of the portion where the concave portion 51 is provided may be 45 degrees or more and 90 degrees or less.

Further, the portion where the recessed portion 51 is provided is not limited to the bottom wall portion 2a. For example, the recess 51 may be provided in the side wall portion 2b or the ceiling wall portion 3a. In addition, it is preferable that the concave portion 51 and the like are not provided in a portion facing the portion in which the concave portion 51 is provided. For example, when the recessed portion 51 is provided in the bottom wall portion 2a, it is preferable that the top wall portion 3a is not provided with a portion that induces bending deformation of another recessed portion 51. FIG. This is because bending deformation is induced on the side where the concave portion 51 is provided when a collision load is input.

Further, as shown in FIG. 22, a concave portion 51d may be provided in the ridgeline portion 2d. As a result, the section modulus of the portion of the hollow member 10B provided with the recess 51d changes significantly in the longitudinal direction, so that the bending deformation with the portion provided with the recess 51d as the starting point of bending can be induced more reliably. can be done.

When the concave portion 51 as described above is provided, the shape of the concave portion 51 is not particularly limited, but the concave portion 51 preferably has the following shape. For example, when the hollow member 10B is formed of a high-strength steel plate, from the viewpoint of formability, the depth D _d of the recess 51 (the surface 511 where the recess 51 is provided and the depth of the recess 51 is The length between the bottom 512 and the direction orthogonal to the plane (see FIG. 23) is preferably three times or more the plate thickness of the hollow member 10B. Moreover, the distance L _d (see FIG. 23) between the edges 513 of the recesses 51 in the longitudinal direction of the hollow member 10B is preferably 50 mm or less.

FIG. 24 is a schematic diagram showing another example of recesses provided in the hollow member according to this embodiment. As shown in FIG. 24, concave portions 51e and 51f extending in the longitudinal direction of the hollow member 10B may be provided side by side along the longitudinal direction of the hollow member 10B. In this case, bending occurs in a portion 510 between the concave portion 51e and the concave portion 51f in the longitudinal direction of the hollow member 10B. That is, since the section modulus of the hollow member 10B provided with the recesses 51e and 51f and the section 510 between the recesses 51e and 51f are different, the section 510 is bent when a collision load is applied. Bending deformation occurs as the origin of Also in this case, when the hollow member 10B is made of a high-strength steel plate, the depth Dd of the recesses 51e and _51f should be at least three times the plate thickness of the hollow member 10B from the viewpoint of formability. is preferred. Further, 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.

Note that the recess 51e and the recess 51f do not necessarily have to be arranged in series as shown in FIG. Also, the recess 51e and the recess 51f do not necessarily have to extend in the longitudinal direction of the hollow member 10B. For example, the angle between the longitudinal direction of the hollow member 10B and the extending direction of the recesses 51e and 51f may be 0 degrees or more and 45 degrees or less.

(Convex part)
FIG. 25 is a cross-sectional view of the frame 1 for explaining an example of convex portions provided on the hollow member according to this embodiment. As shown in FIG. 25, a convex portion 52 is provided on the bottom wall portion 2a. The section modulus of the hollow member 10 at the portion where the protrusion 52 is provided is higher than the section modulus of the hollow member 10 at the portions before and after the portion at which the protrusion 52 is provided (in the longitudinal direction of the hollow member 10). Therefore, when the collision load F shown in FIG. 25 is input to the hollow member 10, the convex portion It is bent so that 52 is on the inside of the bend. The regions 6a and 6b are regions where the section modulus of the hollow member 10 changes in the Y-axis direction. That is, in the longitudinal direction of the hollow member 10 , the portion of the hollow member 10 that includes the convex portion 52 and the regions 6 a and 6 b before and after the convex portion 52 serves as the bend-inducing portion provided in the hollow member 10 .

Therefore, the filling member 4 is arranged in close contact with the inner surface of the side wall portion 2b at least at the portion where the convex portion 52 and the regions 6a and 6b in front and behind the convex portion 52 are provided. As a result, even when bending occurs in the vicinity of the convex portion 52 due to the input of the collision load F, the out-of-plane deformation of the frame 1 can be suppressed, and the load-bearing performance of the frame 1 can be maintained at a high level.

In the example shown in FIG. 25, the bottom wall portion 2a is provided with the convex portion 52, but the present invention is not limited to such an example. For example, the convex portion 52 may be provided on the side wall portion 2b or the ceiling wall portion 3a. More specifically, when the protrusions 52 are provided on the pair of side wall portions 2b and the ceiling wall portion 3a on the same cross section in a part of the hollow member 10 in the longitudinal direction, the cross section in the longitudinal direction of the hollow member 10 Since the modulus changes at the portion where the convex portion 52 is provided, bending of the frame 1 can occur at the portion where the convex portion 52 is provided. Therefore, in this case as well, the convex portion 52 serves as a bend-inducing portion.

Moreover, the shape and arrangement of the protrusions are not limited to the examples described above. 26 to 29 are schematic diagrams showing other examples of projections provided on the hollow member according to this embodiment. The convex portion referred to here is realized, for example, by processing the hollow member 10 or the like. That is, such a convex portion may be provided by deforming a part of the steel plate forming the hollow member 10C. As shown in FIG. 26, a circular convex portion 52a may be provided on the bottom wall portion 2a.

Moreover, as shown in FIG. 27, a plurality of convex portions 52b may be provided on the bottom wall portion 2a. In this case, for example, a plurality of protrusions 52b may be provided side by side in a direction crossing the longitudinal direction of the hollow member 10C. In this case, when a collision load is input, the hollow member 10C is likely to be bent toward the bottom wall portion 2a with any of the regions before and after the plurality of projections 52b in the longitudinal direction of the hollow member 10C serving as the starting point of bending. .

Further, as shown in FIG. 28, a convex portion 52c extending in a direction transverse to the longitudinal direction of the hollow member 10C may be provided on the bottom wall portion 2a. In this case, when a collision load is input, the hollow member 10C is bent toward the bottom wall portion 2a with any of the regions before and after the convex portion 52c in the longitudinal direction of the hollow member 10C as the starting point of bending. The shape of the convex portion 52c is not limited to the rounded rectangle shown in FIG. 28, and may be any shape.

In addition, the direction crossing the longitudinal direction of the hollow member 10C described above is not limited to the direction orthogonal to the longitudinal direction of the hollow member 10C as shown in FIG. For example, the angle formed by the longitudinal direction of the hollow member 10C and the crossing direction on the surface of the portion where the convex portion 52 is provided may be 45 degrees or more and 90 degrees or less.

Further, the portion where the convex portion 52 is provided is not limited to the bottom wall portion 2a. For example, the convex portion 52 may be provided on the side wall portion 2b or the ceiling wall portion 3a. In addition, it is preferable that the convex portion 52 and the like are not provided in the portion facing the portion in which the convex portion 52 is provided. For example, when the convex portion 52 is provided on the bottom wall portion 2a, it is preferable that the top wall portion 3a is not provided with a portion that induces bending deformation, such as another convex portion 52 or the like. This is because bending deformation is induced on the side on which the convex portion 52 is provided when a collision load is input.

Further, as shown in FIG. 29, a convex portion 52d may be provided on the ridgeline portion 2d. As a result, the section modulus of the portion of the hollow member 10C provided with the protrusion 52d changes significantly in the longitudinal direction, so that the bending deformation with the portion provided with the protrusion 52d as the starting point of bending is more reliably induced. can do.

When the protrusions 52 as described above are provided, the form of the protrusions 52 is not particularly limited, but the protrusions 52 preferably have the following forms. For example, when the hollow member 10C is formed of a high-strength steel plate, the height H _d of the convex portion 52 (the surface 521 where the convex portion 52 is provided and the convex The length in the direction perpendicular to the plane between the portion 52 and the top 522 (see FIG. 30) is preferably three times or more the plate thickness of the hollow member 10C. In addition, the distance L _d (see FIG. 30) between the edges 523 of the projections 52 in the longitudinal direction of the hollow member 10C is preferably 50 mm or less.

FIG. 31 is a schematic diagram showing another example of convex portions provided on the hollow member according to the present embodiment. As shown in FIG. 31, convex portions 52e and 52f extending in the longitudinal direction of the hollow member 10C may be provided side by side along the longitudinal direction of the hollow member 10C. In this case, bending occurs in a portion 520 between the convex portions 52e and 52f in the longitudinal direction of the hollow member 10C. That is, of the hollow member 10C, the section provided with the protrusions 52e and 52f and the section 520 between the protrusions 52e and 52f have different section moduli. Bending deformation occurs with 520 as the starting point of bending. Even in this case, when the hollow member 10C is made of a high-strength steel plate, the height (Hd) of the projections 52e and 52f should be at least three times the plate thickness of the hollow member 10C from the standpoint of moldability. Preferably. Further, the portion 520 may be formed with the above-described concave portions, convex portions, thin-walled portions, different-strength portions, or the like, which will be described later.

Note that the convex portions 52e and the convex portions 52f do not necessarily have to be arranged in series as shown in FIG. Also, the convex portions 52e and 52f do not necessarily have to extend in the longitudinal direction of the hollow member 10C. For example, on the surface of the portion where the projections 52e and 52f are provided, the angle between the longitudinal direction of the hollow member 10C and the extending direction of the projections 52e and 52f may be 0 degrees or more and 45 degrees or less. Just do it.

(thickness change part/thin part)
Further, the bottom wall portion 2a may be provided with a plate thickness changing portion as a configuration for realizing the bending inducing portion. FIG. 32 is a schematic diagram showing an example of a plate thickness changing portion provided in the hollow member according to this embodiment. The plate thickness change portion referred to here means a portion where the plate thickness changes in the longitudinal direction of the hollow member 10D. As shown in FIG. 32 , the hollow member 10</b>D includes a first thick plate portion 111 and a second thick plate portion 112 . The first thick plate portion 111 is provided on the end side of the hollow member 10D, and the second thick plate portion 112 is provided continuously with the first thick plate portion 111 along the longitudinal direction of the hollow member 10D. The plate thickness of the steel plate differs between the first plate thickness portion 111 and the second plate thickness portion 112 . Although there is no particular limitation on the magnitude of the plate thickness, from the viewpoint of ensuring the bending rigidity of the entire hollow member 10D, it is preferable that the plate thickness of the second plate thickness portion 112 is larger than the plate thickness of the first plate thickness portion 111. .

In this case, as shown in FIG. 32 , the boundary portion between the first plate thickness portion 111 and the second plate thickness portion 112 becomes the plate thickness change portion 113 . The section modulus in the longitudinal direction of the hollow member 10</b>D changes at the plate thickness change portion 113 . That is, the plate thickness changing portion 113 corresponds to the bending inducing portion 5 . Therefore, when a collision load is input to hollow member 10</b>D, frame 1 bends at plate thickness change portion 113 . Therefore, the filling member 4 is arranged in close contact with at least the bottom wall portion 2a provided with the plate thickness change portion 113 . As a result, out-of-plane deformation of the frame 1 can be suppressed when bending occurs in the vicinity of the plate thickness change portion 113 due to the input of the collision load F.

Also, the bend-inducing portion 5 may be realized by, for example, a thin portion. FIG. 33 is a schematic diagram showing an example of a thin portion provided in the hollow member according to this embodiment. As shown in FIG. 33, the bottom wall portion 2a is provided with a thin portion 114 whose plate thickness is relatively thinner than that of other portions in the longitudinal direction front and rear of the hollow member 10D. The section modulus of the hollow member 10 in the portion including the thin portion 114 is lower than the section modulus of the hollow member 10 in the portions before and after the portion where the thin portion 114 is provided (in the longitudinal direction of the hollow member 10D). That is, the portion of the hollow member 10</b>D where the thin portion 114 is provided corresponds to the bend inducing portion 5 . Therefore, when a collision load is input to the hollow member 10D, the frame 1 bends at the portion where the thin portion is provided so that the thin portion is on the inner side of the bend.

The hollow member 10D having such plate thickness change portions may be formed from a work plate that is cut, pressed, and made from a tailored blank, for example. Such a work plate may be a Tailor Welded Blank (TWB) having weld seams. Further, the plate to be processed may be a tailor rolled blank (TRB) provided with different plate thicknesses by rolling rolls. In the TWB, the thickness difference at the plate thickness change portion can be 0.2 mm or more. Further, in the TRB, the amount of plate thickness change in the plate thickness changing portion per longitudinal direction of the member can be 0.1 mm/100 mm or more.

(Different strength part / strength change part)
FIG. 34 is a cross-sectional view of the frame 1 for explaining an example of different strength portions provided in the hollow member according to this embodiment. As shown in FIG. 34, a different strength portion 53 is provided on the bottom wall portion 2a. The different strength portion 53 is provided, for example, by partially performing heat treatment such as welding, quenching, or tempering on the hollow member 10 . The yield strength of the hollow member 10 at the portion where the different strength portion 53 is provided is different from the yield strength of the hollow member 10 at the portions before and after the portion where the different strength portion 53 is provided (in the longitudinal direction of the hollow member 10). different. Therefore, when the collision load F shown in FIG. 34 is input to the hollow member 10, the different strength portion 53 bends at or near the different strength portion 53 so that the different strength portion 53 is on the inner side of the bend. That is, in the longitudinal direction of the hollow member 10 , the portion of the hollow member 10 that includes the different strength portion 53 serves as the bending induction portion provided in the hollow member 10 .

This bending is caused by plastic deformation of the different strength portion 53 or a region in the vicinity of the different strength portion 53 . Therefore, the filling member 4 is arranged in close contact with the inner surface of the side wall portion 2 b at least in the portion including the vicinity of the different strength portion 53 . As a result, even when bending occurs in the vicinity of the different-strength portion 53 due to the input of the collision load F, the out-of-plane deformation of the frame 1 can be suppressed, and the load-bearing performance of the frame 1 can be maintained at a high level.

In the example shown in FIG. 34, the different strength portion 53 is provided on the bottom wall portion 2a, but the present invention is not limited to this example. For example, the different strength portion 53 may be provided on the side wall portion 2b or the ceiling wall portion 3a. More specifically, when the different-strength portion 53 is provided on the pair of side wall portion 2b and top wall portion 3a on the same cross section in a part of the longitudinal direction of the hollow member 10, the bottom wall portion 2a has the lowest intensity. As a result, bending of the frame 1 with the bottom wall portion 2 a as the bending inner side may occur at the different strength portion 53 . Therefore, also in this case, the different-strength portion 53 serves as a bending-inducing portion.

Also, the arrangement of the different strength portions is not limited to the example described above. 35 and 36 are schematic diagrams showing other examples of different strength portions provided in the hollow member according to this embodiment. The different-strength portion referred to here is realized by welding, heat treatment, or the like to the plate to be processed that forms the hollow member 10E.

As shown in FIG. 35, a different strength portion 120 is provided along the cross-sectional circumferential direction with respect to the longitudinal direction of the hollow member 10E. In this case as well, the portion of the hollow member 10</b>E provided with the different strength portion 120 corresponds to the bending induction portion 5 . Therefore, when a collision load is input to the hollow member 10E, the frame 1 bends at the portion where the different strength portion 120 is provided so that the different strength portion 120 is on the inside of the bend.

Note that such a different strength portion may be partially provided in at least one of the wall portions forming the cross section of the hollow member 10E, such as the bottom wall portion 2a, as shown in FIG. 36, for example. Even in this case, when a collision load is input to the hollow member 10E, the frame 1 bends at the portion where the different strength portion 121 is provided so that the different strength portion 121 is on the inside of the bend.

Moreover, the bending induction part 5 may be implemented by, for example, a strength changing part. FIG. 37 is a schematic diagram showing an example of a strength changing portion provided in the hollow member according to this embodiment. As shown in FIG. 37, the hollow member 10E includes a first strength portion 122 and a second strength portion 123. As shown in FIG. The first strength portion 122 is provided on the end portion side of the hollow member 10E, and the second strength portion 123 is provided continuously with the first strength portion 122 along the longitudinal direction of the hollow member 10E. The yield strength of the steel plate differs between the first strength portion 122 and the second strength portion 123 . Although the magnitude relationship of the yield strength is not particularly limited, it is preferable that the yield strength of the second strength portion 123 is higher than the yield strength of the first strength portion 122 from the viewpoint of ensuring the bending rigidity of the hollow member 10E as a whole.

In this case, as shown in FIG. 37 , the boundary portion between the first strength portion 122 and the second strength portion 123 becomes the strength change portion 124 . The yield strength in the longitudinal direction of the hollow member 10E changes at this strength change portion 124 . In other words, the strength changing portion 124 corresponds to the bending induction portion 5 . Therefore, when a collision load is input to hollow member 10</b>E, frame 1 bends at strength change portion 124 .

(combination)
In addition, in the hollow member having a bent portion, a portion for inducing bending, such as the hole portion shown in the above example, may be further provided on the bending inner portion of the bent portion. FIG. 38 is a cross-sectional view of the frame 1 for explaining an example of combinations of bent portions and holes provided in the hollow member according to this embodiment. As shown in FIG. 38, the hollow member 10 is provided with a bent portion 5A, and the bottom wall portion 2a is provided with a hole portion 54 on the inside portion of the bent portion. The filling member 4 is arranged in close contact with the inner surface of the side wall portion 2 b in the bent portion 5 . As a result, the hollow member 10 can be more reliably bent at the bent portion 5 by inputting the collision load F.

The combination of bending inducers is not limited to the example shown in FIG. 38, and by combining a plurality of examples of the bend inducers shown above, bending of the hollow member 10 at the bend inducers can be caused more reliably. For example, the bend-inducing portion may be realized by a combination of at least two or more of the bent portion, concave portion, convex portion, hole portion, plate thickness change portion, thin portion, different strength portion, and strength change portion described above.

<5. Example of shape of closed cross section of hollow member>
Next, examples of closed cross-sectional shapes of the hollow member 10 will be described. FIG. 39 is a sectional view showing a section orthogonal to the longitudinal direction of a first example of hollow member 10 according to another embodiment of the present invention. As shown in FIG. 39, the closed cross section of the hollow member 10 has a substantially hexagonal shape symmetrical about the X axis. Among them, four vertices 2d, 2d, 2f, and 2f are present in a portion of the first structural member 2 substantially orthogonal to the X-axis direction. Here, if the internal angle ang1 of the vertex 2d is smaller than each ang2 of the vertex 2f, the vertex 2d is defined as the edge line portion 2d. That is, the portion sandwiched between the pair of edge line portions 2d including the vertices 2f, 2f is defined as the bottom wall portion 2a.

FIG. 40 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a second example of the hollow member 10 according to another embodiment of the invention. As shown in FIG. 40, the first structural member 2 and the second structural member 30 have a hat-shaped cross-sectional shape. That is, the hollow member 10 is formed by two structural members having a hat-shaped cross section. In this case, the side wall portion 2b of the first structural member 2 and the side wall portion 30b of the second structural member 30 are separated by the ridgeline portion 2e of the first structural member 2 and the ridgeline portion 30e of the second structural member 30. It is defined as one continuous side wall portion (continuous side wall portion) having both ends of the ridgeline portion 2d and the ridgeline portion 30d. That is, the closed cross section of the hollow member 10 is formed by the bottom wall portion 2a, the pair of continuous side wall portions, and the bottom wall portion 30a (corresponding to the top wall portion).

Further, the hollow member 10 and the closed cross-sectional shape of the hollow member 10 are not limited to the examples shown in FIGS. If the shape of the closed cross section of the hollow member 10 is substantially polygonal, and the portions corresponding to the bottom wall portion, the pair of side wall portions, and the top wall portion forming the closed cross section can be defined, the technology according to the present invention can be applied to the hollow member. 10. For example, the hollow member may be a hollow member having a closed cross section obtained by stacking two structural members having a U-shaped cross section so that the opening portions face each other. Further, the hollow member may be a hollow member formed by hydroforming or bending a circular pipe.

Next, examples of the present invention will be described. In order to confirm the effect of the present invention, in the present embodiment, the effect of improving the collision safety performance of the frame by the filler member 4 was verified. In addition, the following examples were performed only to verify the effects of the present invention, and the present invention is not limited to the following examples. Further, the filling member according to each example and comparative example will be referred to as "filling member 4" unless otherwise specified.

In order to verify the effect of improving the collision safety performance of the frame by the filler member 4, the present inventors used simulations to calculate the maximum load L _max (kN) of various frames with respect to the same collision load. The maximum load L _max means the maximum load value in the load-stroke curve for the frame 1 when the collision load F is input to the frame 1 . That is, it can be said that the larger the _maximum load Lmax for the same collision load, the higher the load bearing performance, that is, the higher the collision safety performance.

In this embodiment, a filling member 4 is placed in close contact with predetermined portions inside the bent portions 5A and 5B of the frame 1 shown in FIG. Collided the collider. Thereby, the collision load F is input to the frame 1 . The maximum load L _max of the collision object after the collision load F was input was analyzed for each example, comparative example, and reference example, and the results were examined.

First, the test conditions of this example are shown. The dimensions of the frame 1 used in this example (see FIG. 4) are as follows (unit: mm).
L _FL =500
D _FL1 =70
_DFL2 = 90
S _FL =60
L _FMA =70
L _FMB =70

The plate thickness of the first structural member 2 is 2.0 mm, and the strength of the first structural member 2 is 780 MPa. The plate thickness of the second structural member 3 is 1.5 mm, and the strength of the second structural member 3 is 690 MPa. Also, the weight of the frame 1 is 3.63 kg.

The arrangement of the filling member 4 in the bent portion 5A according to each example and comparative example is as follows. Numerical values in parentheses are values relating to the thickness and arrangement position of the filling member 4 .
Example 1: Arrangement shown in FIG. 5 (a=10 mm, b ₁ =15 mm, b ₂ =15 mm)
Example 2: Arrangement shown in FIG. 7 (a=10 mm)
Example 3: Arrangement shown in FIG. 7 (a=3 mm)
Example 4: Arrangement shown in FIG. 7 (a=30 mm)
Example 5: Arrangement shown in FIG. 7 (a=50 mm)
Example 6: Arrangement shown in FIG. 8 (a ₁ , a ₂ , c ₁ , c ₂ =10 mm)
Example 7: Arrangement shown in FIG. 9 (a, c=10 mm)
Example 8: Arrangement shown in FIG. 10 (a ₁ , a ₂ =10 mm)
Example 9: Arrangement shown in FIG. 11 (a=10 mm)
Example 10: Arrangement shown in FIG. 12 (a ₁ , a ₂ , a ₃ =10 mm)
Comparative Example 1: Arrangement shown in FIG. 41 (a ₁ , a ₂ =10 mm, b ₁ to b ₄ =15 mm)

Here, FIG. 41 is a cross-sectional view showing an arrangement example in the bent portion 5A of the filling member according to Comparative Example 1. As shown in FIG. As shown in FIG. 41, filling members 44a and 44b according to Comparative Example 1 are arranged in close contact with the inner surfaces of the respective central portions of side wall portion 2b.

The filling member 4 according to Examples 1 to 8 is arranged in close contact with the inner surface of the bottom wall portion 2a (and the inner side of the ridge line portion 2d). The filling member 4 is arranged in close contact with the inner surface of the top wall portion 3a (and the inner side of the ridgeline portion 2e). Further, the filling member 4 according to Examples 9 and 10 is arranged in close contact with the inner surfaces of the bottom wall portion 2a and the top wall portion 3a also at the bent portion 5B.

Here, the density of the filling member 4 was set to 176 kg/m ³ , and the Young's modulus and yield stress of the filling member 4 were set to 100 MPa and 2.1 MPa.

Further, in the reference example, the frame 1 is not provided with the filling member 4 .

Table 1 shows the total weight of the frame 1 and the weight of the filling member 4 according to each example, comparative example and reference example.

The weight of the collision object that collided with the end of the frame 1 was 201 kg, and the speed of the collision object when it collided with the end of the frame 1 was 12 m/s.

Table 2 shows the weight of the filling member 4, the maximum load amount L _max of the frame, and the load improvement rate I _L (kN/g) according to each example, comparative example, and reference example. The maximum load amount L _max is the load that the frame can withstand against the collision load. Further, the load improvement rate I _L is the difference between the maximum load of the frame according to the reference example and the maximum load of the frame according to one example, and the weight of the filling member 4 provided on the frame according to the one example. It is a value divided by (g). That is, the load improvement rate _IL is a value that indicates the mass efficiency of the load bearing performance of the filling member 4 .

First, the load improvement rate I _L with respect to the placement of the filling member 4 was compared. Comparing Example 1 and Comparative Example 1, the load improvement rate is higher when the filling member 4 is arranged on the inner surface of the bottom wall portion 2a (top wall portion 3a) than on the inner surface of the side wall portion 2b. It can be seen that _IL is high. That is, it was shown that it is preferable to dispose the filling member 4 on the inner surface of the bottom wall portion 2a (top wall portion 3a) in order to efficiently improve the load bearing performance.

Further, when Examples 6 and 7 and _Comparative Example 1 were compared, Examples 6 and 7 showed better results in terms of the load improvement rate IL, although the weight of the filling member was smaller. Therefore, arranging the filling member 4 inside the ridge 2d (2e) can improve the mass efficiency related to the load bearing performance rather than arranging it only on the inner surface of the side wall 2b. On the other hand, it was shown that when the filling member 4 was arranged only on the inner surface of the side wall portion 2b, it did not contribute much to the improvement of the load bearing performance.

Further, when Example 1 and Example 2 were compared, the same results were obtained for the _maximum load amount _Lmax , but Example 1 showed better results for the load improvement rate IL. Therefore, by arranging the filling member 4 in the central portion of the bottom wall portion 2a (the top wall portion 3a), the mass efficiency of the filling member 4 regarding load bearing performance can be improved. Therefore, it is possible to further reduce the weight of the vehicle.

Moreover, a comparison of Examples 2 to 5 showed that both the maximum load amount L _max and the load improvement rate I _L were improved as the wall thickness a of the filling member 4 was increased. Therefore, by adjusting the filling amount of the filling member 4 arranged on the inner surface of the bottom wall portion 2a (the top wall portion 3a) according to the collision safety performance required of the frame, while ensuring appropriate load bearing performance, , vehicle weight reduction can be achieved.

Further, when Examples 6 and 8 and Examples 7 and 9 were compared, Examples 8 and 9 showed better results with respect to the maximum load amount L _max . Therefore, by arranging the filling member 4 in close contact with the inner surface of the side wall portion 2b, the load resistance of the frame 1 can be further improved compared to simply arranging the filling member 4 in close contact with the inside of the ridge line portion 2d (2e). can be enhanced.

Further, in Example 10, a high maximum load L _max was obtained. Therefore, by arranging the filling member 4 in continuous contact with not only the bottom wall portion 2a (top wall portion 3a) but also the ridge portion 2d (2e) and the side wall portion 2b, the impact energy of the frame 1 can be reduced. Not only can the absorption properties be improved, but also the load bearing performance of the frame 1 can be further improved.

As described above, by arranging the filling member 4 mainly in close contact with the inner surface of the bottom wall portion 2a (top wall portion 3a) as shown in the above embodiment, the thinned frame 1 maintains high load bearing performance. It is possible to

Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present invention.

Reference Signs List 1 (vehicle) frame 2 first structural member 2a bottom wall portion 2b side wall portion 2c flange portion 2d, 2e ridgeline portion 3, 30 second structural member 3a top wall portion 30a bottom wall portion 30b side wall portion 3c, 30c joining Part 30e Ridgeline part 4 Filling member 5 Bending part (bending inducing part)
REFERENCE SIGNS LIST 10 Hollow member 50, 54 Hole 51 Concave portion 52 Protruding portion 53 Different strength portion

Claims (11)

a bottom wall portion, a pair of side wall portions rising from both ends of the bottom wall portion, and a top wall portion facing the bottom wall portion, the bottom wall portion, the pair of side wall portions, and the top wall portion a hollow member forming a closed cross section by
a reinforcing member arranged so as to be in close contact with one inner surface of the bottom wall portion or the top wall portion and not in close contact with the other inner surface;
with
The hollow member further comprises a bend-inducing portion in a part of the hollow member in the longitudinal direction,
One of the bottom wall portion and the top wall portion is arranged inside the bending induced by the bending inducing portion, and the other is arranged outside the bending induced by the bending inducing portion,
The surface of the reinforcing member is divided into a contact portion that is in close contact with the inner surface of the hollow member and a non-contact portion that is a remaining area other than the contact portion and is not in close contact with the hollow member,
The non-adhered portion is arranged so as to be adjacent to the space extending in the longitudinal direction inside the hollow member without a break,
The reinforcing member is a filling member ,
The reinforcing member has an end surface in planar contact with the inner surface of the hollow member at an end portion in the circumferential direction orthogonal to the longitudinal direction of the hollow member, or extends from the inner surface of the hollow member to the inner side of the hollow member. A rising end face is formed,
The reinforcing member is partially arranged corresponding to the bending-inducing portion in the longitudinal direction of the hollow member, and the entirety of the reinforcing member does not adhere to the inner surface of one of the bottom wall portion and the top wall portion .
Structural members for vehicles. 2. The structural member for a vehicle according to claim 1, wherein said reinforcing member is arranged in close contact with an inner side of a ridge connecting said side wall and said bottom wall or said ceiling wall. 3. The structural member for a vehicle according to claim 2, wherein said reinforcing member is arranged in close contact with an inner surface of said side wall portion. The structural member for a vehicle according to any one of claims 1 to 3, wherein said reinforcing member is arranged along an inner surface of a portion corresponding to an inner side of bending induced by said bending inducing portion. 5. The structural member for a vehicle according to claim 4, wherein said bend-inducing portion is a portion having a radius of curvature of 260 mm or less of a center axis along said longitudinal direction formed by a center of gravity of a cross section of said hollow member. 6. The structural member for a vehicle according to claim 4, wherein said bending induction portion includes a portion where the section modulus of said hollow member changes in said longitudinal direction. 7. The structural member for a vehicle according to claim 6, wherein said bending induction portion includes a portion provided with at least one of a concave portion, a convex portion, a hole portion, a plate thickness changing portion and a thin portion. 8. The structural member for a vehicle according to claim 7, wherein at least one of said concave portion, said convex portion, and said plate thickness changing portion is provided in plurality along said longitudinal direction of said hollow member. 6. The structural member for a vehicle according to claim 4, wherein said bending induction portion includes a portion where the yield strength of said hollow member varies in said longitudinal direction. The vehicle structural member according to any one of claims 1 to 9, wherein the metal plate forming the hollow member has a plate thickness of 2.3 mm or less. The vehicle structural member is at least one of a front side member, a rear side member, a crash box, a pillar, a floor reinforcement, a floor cross member, a bumper reinforcement, a side sill, a roof side rail, a roof center reinforcement, or a tunnel. The vehicle structural member according to any one of claims 1 to 10, wherein:

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