JP7331026B2 - Vehicle structural member - Google Patents

Description

The present invention relates to a vehicle structural member.

Conventionally, various techniques related to structural members for vehicles have been proposed. For example, in the vehicle body side structure described in Patent Document 1 below, the hinge reinforcement disposed inside the outer reinforcement of the center pillar connects a pair of vertical hinge walls and a pair of vertical hinge walls. and a hinge connection wall that connects to the pair of hinge vertical walls, and joint projections that protrude toward the pair of center pillar vertical walls of the outer reinforcement and are joined to the pair of center pillar vertical walls are formed on the pair of hinge vertical walls. , a configuration in which the end portion of the joint protrusion on the hinge connecting wall side is positioned further away from the center pillar connecting wall than the center of the center pillar vertical wall in the vehicle width direction.

JP 2013-220807 A

However, since the hinge reinforcement is a vertically long steel plate member with a substantially U-shaped cross section, it is necessary to increase the plate thickness in order to further improve the bending rigidity, and it is necessary to reduce the weight of the center pillar. is difficult. Therefore, there is a demand for a structural member for a vehicle that is lighter in weight than when it is reinforced using hinge reinforcement and has sufficient bending rigidity.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a structural member for a vehicle that has sufficient bending rigidity and can be made lighter.

In order to solve the above problems, a first invention is a vehicle structural member comprising a pair of vertical walls facing each other and a connecting wall connecting the pair of vertical walls, wherein the pair of vertical walls In the inner wall of each of the vertical walls facing each other, the reinforcing material is applied from the longitudinal central portion of the inner edge on the side of the connecting wall to the longitudinal both ends of the outer edge on the outer side with respect to the connecting wall. A vehicle structural member having a band-shaped vertical wall reinforcing portion provided by laser clad processing so as to extend in an arch shape toward the vehicle.

A second invention is the structural member for a vehicle according to the first invention, wherein the connecting wall is an inner wall of the connecting wall that is continuous with the inner wall of the vertical wall, and the reinforcing material is a top portion of each of the vertical wall reinforcing portions on both side edges. A structural member for a vehicle, having a pair of connecting wall reinforcing portions provided by laser clad processing so as to extend in a band shape of a predetermined length from a position opposite to the longitudinal direction both sides.

In a third aspect of the invention, in the vehicle structural member according to the second aspect, the connecting wall reinforcing portion is provided at a predetermined position symmetrical with respect to the widthwise central portion of the inner wall of the connecting wall on both sides in the longitudinal direction from the longitudinal central portion. It is a structural member for a vehicle having a first hole formed to extend to.

A fourth invention is the vehicle structural member according to any one of the first to third inventions, wherein the vertical wall reinforcing portion has a shape symmetrical with respect to the longitudinal central portion of the inner wall of the vertical wall. A structural member for a vehicle having a pair of second holes formed at predetermined positions symmetrical with respect to the longitudinal central portion.

A fifth invention is the vehicle structural member according to any one of the first to fourth inventions, wherein the vertical wall reinforcing portion has a thickness at the central portion in the longitudinal direction extending in the arch shape. The vehicle structural member is formed so as to be larger than the thickness of both end portions.

ADVANTAGE OF THE INVENTION By taking the structure of said each invention, this invention can achieve weight reduction, ensuring the bending rigidity of a structural member for vehicles.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows an example of the structural member for vehicles which concerns on this embodiment. FIG. 2 is a cross-sectional view of the vehicle structural member shown in FIG. 1 taken along line II. FIG. 2 is a plan view of the vehicle structural member shown in FIG. 1 as viewed from arrow III. 4 is a flowchart for explaining the flow of processing for manufacturing the vehicle structural member according to the present embodiment; It is a figure explaining the analysis model of the shape optimization analysis of the structural member for vehicles. FIG. 6 is a side view for explaining the analysis model of FIG. 5; It is a figure explaining the load conditions loaded to an analysis model. FIG. 11 is a side view for explaining a method of determining a stiffness-contributing clad shape of a vertical wall of a reinforcing member based on a stiffness-contributing portion detected by shape optimization analysis; FIG. 11 is a plan view for explaining a method of determining a stiffness-contributing cladding shape of a connecting wall of a reinforcing member based on a stiffness-contributing portion detected by shape optimization analysis; It is a figure which shows an example which shape|molds a reinforcement part by laser clad processing. It is a mimetic diagram explaining laser cladding processing. FIG. 10 is a side view of Comparative Example 1 on which a three-point bending strength test was performed; FIG. 2 is a side view of Inventive Example 1 subjected to a three-point bending strength test. It is a figure which shows an example of a three-point bending-strength test result. It is a figure which shows the vertical-wall reinforcement part of the structural member for vehicles which concerns on other embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a vehicle structural member according to the present invention will be described in detail below with reference to the drawings. First, a vehicle structural member 1 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. The present invention is similarly applied to side sills, roof side rails, front pillar reinforcements, center pillar reinforcements, bumper reinforcements, door beams, and the like.

1 to 3 show a schematic configuration of a vehicle structural member 1 according to this embodiment. As shown in FIGS. 1 to 3, the vehicle structural member 1 includes a press formed body 11 formed by cold press forming, and a pair of vertical wall reinforcing portions 12 and a pair of vertical wall reinforcing portions 12 provided by laser clad processing as will be described later. and a connecting wall reinforcing portion 13 (see FIG. 10). The press-formed body 11 may be formed by hot press-forming.

The press-formed body 11 is a steel plate for cold press having a thickness of about 1 mm to 2 mm, and is formed into a substantially hat-shaped cross section by cold press forming. Specifically, the press-formed body 11 includes a pair of vertical walls 11A and 11B facing each other, a connecting wall 11C having a substantially rectangular shape in plan view that connects one side edge of the pair of vertical walls 11A and 11B, and a pair of A pair of flange portions 11D and 11E are formed by bending outward from the other side edge of the vertical walls 11A and 11B, that is, the side edge on the opening side substantially parallel to the connecting wall 11C. .

The pair of vertical wall reinforcing portions 12 are formed on the inner walls 15A and 15B of the pair of vertical walls 11A and 11B facing each other, starting from the longitudinal central portion of the inner edge on the side of the connecting wall 11C and extending to the connecting wall 11C. On the other hand, a metal strip having a thickness of about 1 mm to 5 mm is provided to extend in an arch shape as indicated by a dashed line 17 toward both ends in the longitudinal direction of the outer edge on the outside (opening side). Each vertical wall reinforcing portion 12 is provided by laser clad processing as will be described later, and the entire surface thereof is surface-bonded to each of the vertical wall inner walls 15A and 15B by metal bonding.

As shown in FIGS. 1 and 2, each strip-shaped vertical wall reinforcing portion 12 is formed to have a slightly narrower width in the central portion in the longitudinal direction. Each vertical wall reinforcing portion 12 gradually extends along the edge of each vertical wall inner wall 15A, 15B on the side of the connecting wall 11C toward the approximate central position from the longitudinal center to each longitudinal end. It has a pair of widened portions 12A extending so that the width gradually narrows gradually after the widened portion. Each vertical wall reinforcing portion 12 is spaced apart from the edge of each vertical wall inner wall 15A, 15B on the side of the connecting wall 11C at the longitudinal end portion of each wide portion 12A, and extends outwardly of each vertical wall inner wall 15A, 15B. It has a pair of curved portions 12B curved and extended toward the outer edge (opening side) in a substantially circular arc shape having substantially the same width and a large radius of curvature.

The pair of wide width portions 12A and the pair of curved portions 12B are formed in a symmetrical shape with respect to the longitudinal central portion of each of the vertical inner walls 15A and 15B, and are formed at symmetrical positions with respect to the longitudinal central portion. preferably A pair of wide width portions 12A has a second hole portion 19 extending along the longitudinal direction of each of the vertical inner walls 15A and 15B at substantially the central portion in the width direction orthogonal to the longitudinal direction.

The pair of second holes 19 are formed in a symmetrical shape with respect to the longitudinal central portion of each of the vertical inner walls 15A and 15B, and are formed at symmetrical positions with respect to the longitudinal central portion. Each second hole 19 is formed in a shape substantially similar to that of the wide portion 12A, and each wide portion 12A is bifurcated along the periphery of the second hole and then joined again to form the curved portion 12B. is formed to reach

As shown in FIGS. 1 to 3, the pair of connecting wall reinforcing portions 13 are opposed to the top portions of the vertical wall reinforcing portions 12 extending in an arch shape on both side edges of the connecting wall inner wall 21 on the opening side of the connecting wall 11C. From the position where it extends to both sides in the longitudinal direction, to the position facing each other near the longitudinal outer ends of the pair of second holes 19 of each vertical wall reinforcing part 12, in a strip made of metal with a thickness of about 1 mm to 5 mm. is formed in In addition, the pair of connecting wall reinforcing portions 13 are provided at their widthwise central portions with longitudinally extending longitudinally extending portions from the longitudinal central portion to positions opposed to the longitudinal inner end portions of the pair of second hole portions 19 . 1 hole 22 is formed. The width dimension of each first hole portion 22 is set to approximately one third of the width dimension of the connecting wall reinforcing portion 13 .

Specifically, each connecting wall reinforcing portion 13, which is band-shaped in plan view, extends from both ends in the longitudinal direction of the end edge of each vertical wall reinforcing portion 12 on the side of the connecting wall 11C to the substantially central portion in the longitudinal direction of each second hole portion 19. While the length in the longitudinal direction gradually narrows to the opposite position, it extends inward in the width direction to about 1/6 of the width dimension of the inner wall 21 of the connecting wall. Then, each connecting wall reinforcing portion 13 has a length in which both longitudinal ends are opposed to each other near the longitudinal outer ends of the second holes 19, and has a width approximately equal to the width of the inner wall 21 of the connecting wall. It extends inward in the width direction up to ⅓. Therefore, the pair of connecting wall reinforcing portions 13 are arranged along the longitudinal direction at a distance of about 1/3 of the width dimension of the connecting wall inner wall 21 from each other. The longitudinal length of each connecting wall reinforcing portion 13 is set to approximately half the length of the vertical wall reinforcing portion 12 in the longitudinal direction.

Next, an example of a process for manufacturing the vehicle structural member 1 configured as described above will be described with reference to FIGS. 4 to 11. FIG. In this embodiment, a reinforcing member 28 (see FIG. 5) is provided on the inner wall of an outer panel 27 (see FIG. 5) corresponding to the press-formed body 11 that is press-formed into a hat-shaped cross section, as shown in FIG. By executing the processing of steps S11 to S15, the shape optimization analysis of the reinforcing member 28 is performed, and by executing the processing of step S16, the vehicle structural member 1 is created. As a result, it is possible to improve the bending strength of a vehicle component having a substantially rectangular closed cross-sectional structure, such as a B-pillar, using the vehicle structural member 1 and reduce the weight of the vehicle component. Note that the processing of steps S11 to S15 can be executed on a computer.

[Analysis model generation process]
As shown in FIG. 4, first, in step S11, an analysis model 25 (see FIG. 5) is generated using the outer panel 27 corresponding to the press-formed body 11 (see FIG. 1), which is the part to be analyzed. In the present embodiment, as shown in FIGS. 5 and 6, the analysis model 25 includes an outer panel 27 having a hat-shaped cross-sectional shape corresponding to the press-formed body 11 of the vehicle structural member 1, and a groove-shaped cross-sectional shape. It is composed of a reinforcing member 28 having a surface and an inner panel 29 which is rectangular in plan view and has a flat plate shape and closes the opening side of the outer panel 27 .

As shown in FIG. 5, the outer panel 27 includes a pair of vertical walls 27A and 27B that face each other, a connecting wall 27C that is substantially rectangular in plan view and connects one side edge of the pair of vertical walls 27A and 27B, A pair of flange portions 27D and 27E are formed by bending outward from the other side edge of the pair of vertical walls 27A and 27B, that is, the side edge on the opening side, substantially parallel to the connecting wall 27C. there is

Further, the outer panel 27 is set to have substantially the same dimensions and shape as the press-formed body 11 having a hat-shaped cross-sectional shape. For example, the outer panel 27 has a length of about 500 mm to 600 mm, a width of each of the vertical walls 27A and 27B of about 60 mm to 70 mm, a width of the connecting wall 27C of about 100 mm to 110 mm, and a pair of flange portions 27D and 27E. The distance between the outer edges is set at approximately 165-175 mm.

The reinforcing member 28 having a groove-shaped cross section is set to have substantially the same length as the outer panel 27, and connects the pair of vertical walls 28A, 28B and one side edge of the pair of vertical walls 28A, 28B in plan view. and a substantially rectangular connecting wall 28C. Then, as shown in FIG. 6, the connecting wall 28C is overlapped so as to cover the inner wall of the connecting wall 27C of the outer panel 27, and is fully joined (fixed) in close contact. The pair of vertical walls 28A and 28B are overlapped so as to substantially cover the inner walls of the pair of vertical walls 27A and 27B of the outer panel 27, and are fully joined (fixed) in close contact.

As shown in FIG. 5, the flat plate-like inner panel 29 having a rectangular rectangular shape in plan view is set to have the same length as the outer panel 27, and is spaced between the outer edges of the pair of flange portions 27D and 27E of the outer panel 27. As shown in FIG. is set to a width approximately equal to the distance of Then, as shown in FIG. 6, the inner panel 29 is overlapped along the longitudinal direction of the outer panel 27 so as to cover the pair of flange portions 27D and 27E, and is spot-welded at intervals of about 20 mm to 50 mm in close contact. It is fixed by laser welding or the like, and constitutes an analysis model 25 having a substantially rectangular closed cross-sectional structure.

[Material property setting process]
Next, in step S12, the material properties of each of the outer panel 27, the reinforcing member 28, and the inner panel 29 that constitute the analysis model 25 generated in step S11 are set. In the present embodiment, the outer panel 27 and the inner panel 29 are made of high-strength steel with a thickness of about 1.0 mm to 2.3 mm and a tensile strength of 590 MPa or more (for example, 1470 MPa to 2000 MPa). , specific gravity, etc. are set. The reinforcing member 28 has a thickness of about 1.0 mm to 5.0 mm and a high tensile strength steel plate having a tensile strength of 590 MPa or more (for example, 1470 MPa to 2000 MPa), or a thickness of about 1.0 mm to 5 mm by laser clad processing described later. The Young's modulus, Poisson's ratio, specific gravity, etc. of the metal powder 43 (see FIG. 11) melted and solidified at .0 mm are set.

[Stress state setting process]
Next, in step S13, the state of stress generated in the analysis model 25 generated in step S11 is set. Specifically, as shown in FIG. 7, the inner panel 29 side of the analysis model 25 is horizontally supported by each support member 31 having a semicircular cross section with a support point interval of L1 (for example, L1=500 [mm]). do. Then, an impactor 32 having a semicircular cross section with a radius R1 (for example, R1 = 90 [mm]) and longer than the width of the connecting wall 27C applies a downward load W1 to the central position in the longitudinal direction of the outer panel 27 of the analysis model 25. (eg, W1=30 [kN]).

[Rigidity contributing part detection process]
Next, in step S14, shape optimization analysis is performed on the analysis model 25 for which the stress state is set in step S13, and the stiffness contributing portions, which are portions that contribute highly to the stiffness of the reinforcing member 28, are detected. As a method of shape optimization analysis, for example, topology optimization analysis is performed. In this embodiment, the remaining volume ratio is 20% of the initial shape. As a method of shape optimization analysis, topography optimization analysis, numerical optimization analysis, etc. may be used in addition to topology optimization analysis.

An example of the result of shape optimization analysis will be described with reference to FIGS. 8 and 9. FIG. 8 and 9 show remaining elements (rigidity-contributing portions) of the reinforcing member 28 as a result of the shape optimization analysis of the analysis model 25 . The light gray portion in FIG. 8 indicates the remaining portion (rigidity contributing portion) of the vertical wall 28A of the reinforcing member 28, and the remaining portion (rigidity contributing portion) of the vertical wall 28B of the reinforcing member 28 is substantially the same. Remains in shape. A light gray portion in FIG. 9 indicates a remaining portion (rigidity contributing portion) of the connecting wall 28C of the reinforcing member 28. As shown in FIG.

As shown in FIG. 8, the remaining portions (rigidity-contributing portions) of the vertical walls 28A and 28B extend from the longitudinal central portion of the inner edge of the connecting wall 28C to the outside (opening side) of the connecting wall 28C. ) toward both ends in the longitudinal direction of the outer edge thereof, it is generally strip-shaped and remains in the shape of an arch as indicated by the dashed line 35 . The remaining portions (rigidity-contributing portions) of the vertical walls 28A and 28B remain with a slightly narrower width in the central portion in the longitudinal direction, and extend from the central portion in the longitudinal direction to the ends in the longitudinal direction. After the width gradually widens along the edge of the vertical walls 27A and 27B on the side of the connecting wall 27C, the width gradually narrows gradually.

The remaining portions (rigidity contributing portions) of the vertical walls 28A and 28B are spaced apart from the edges of the vertical walls 27A and 27B on the side of the connecting wall 27C and outside (opening side) of the vertical walls 27A and 27B. It remains curved in a substantially circular arc shape with a large radius of curvature with substantially the same width toward the outer edge. In the pair of wide portions symmetrical with respect to the longitudinal central portion of each of the vertical walls 27A and 27B, along the longitudinal direction of each of the vertical walls 27A and 27B, at approximately the central portion in the width direction orthogonal to the longitudinal direction. A portion 36 (corresponding to the second hole portion 19) that does not remain in the shape of a long slot is formed.

As shown in FIG. 9, the remaining portion (rigidity contributing portion) of the connecting wall 28C is the end edge portion of the remaining portion (rigidity contributing portion) of each of the vertical walls 28A and 28B in each of the vertical walls 27A and 27B on the side of the connecting wall 27C. From both ends in the longitudinal direction, the length in the longitudinal direction gradually narrows and remains extending inward in the width direction to about 1/6 of the width dimension of the connecting wall 27C. Then, from each remaining portion of the connecting wall 28C, both ends in the longitudinal direction of the remaining portions (rigidity-contributing portions) of the vertical walls 28A and 28B do not remain in the shape of a long hole 36. , and further extend widthwise inwardly to about one-third of the width dimension of connecting wall 27C.

In each remaining portion of the connecting wall 28C, a portion 37 (corresponding to the first hole portion 22) that does not remain is formed in the shape of an elongated hole along the longitudinal direction at the center portion in the width direction. there is Therefore, in the central portion of the connecting wall 28C in the width direction, there is formed a portion where the connecting wall 28C does not remain over the entire length in the longitudinal direction with a width dimension of about 1/3 of the width dimension of the connecting wall 27C.

[Rigidity Contributing Cladding Shape Determining Step]
Next, in step S15, based on the rigidity-contributing portion of the reinforcing member 28 detected in step S14, a pair of vertical walls 15A and 15B of the press-formed body 11 and the connecting wall inner wall 21 are formed by laser clad processing. The shapes of the wall reinforcing portion 12 and the pair of connecting wall reinforcing portions 13 (rigidity-contributing cladding shape) are determined. Specifically, as shown in FIG. 8, the outer peripheries of the remaining portions (rigidity-contributing portions) of the vertical walls 28A and 28B remaining on the vertical walls 27A and 27B of the outer panel 27 are smoothly connected to form a dashed line. A pair of second holes 19 are formed by forming a substantially strip-shaped portion extending in an arch shape along the 35 and smoothly connecting the inner circumference of each portion 36 where the vertical walls 28A and 28B of the reinforcing member 28 do not remain. The shape (stiffness-contributing clad shape) of the vertical wall reinforcing portion 12 is determined.

Further, as shown in FIG. 9, a pair of substantially strip-shaped portions extending in the longitudinal direction smoothly connect the outer peripheries of the remaining portions (rigidity contributing portions) of the connecting wall 28C remaining on the connecting wall 27C of the outer panel 27. and smoothly connect the inner circumference of each portion 37 where the connecting wall 28C of the reinforcing member 28 does not remain, and the shape of the pair of connecting wall reinforcing portions 13 having the long first hole 22 along the longitudinal direction decide. Therefore, the edge of each vertical wall reinforcing portion 12 on the side of the connecting wall 27C and the edge of the pair of connecting wall reinforcing portions 13 on the side of the vertical walls 27A and 27B are continuously integrated.

[Laser cladding process]
Next, in step S16, according to the rigidity-contributing cladding shape determined in step S15, the pair of vertical wall reinforcing portions 12 and the pair of connecting portions are attached to the pair of vertical wall inner walls 15A and 15B and the connecting wall inner wall 21 of the press-formed body 11. The vehicle structural member 1 is manufactured by forming the wall reinforcing portion 13 by laser clad processing.

Specifically, as shown in FIG. 10, the laser cladding device 41 includes a coaxial nozzle 45 through which a laser beam 42 passes and for ejecting a metal powder 43 (reinforcing material) that is pressure-fed. Then, the laser cladding device 41 relatively moves the coaxial nozzle 45 along the shape of the pair of vertical wall reinforcing portions 12 and the pair of connecting wall reinforcing portions 13 (rigidity contributing clad shape) determined in step S15. , while supplying the metal powder 43 to the surface of the press molded body 11, the laser beam 42 is irradiated.

That is, as shown in FIG. 11, after forming a molten pool 46 in which the metal powder 43 and the base material are melted at the irradiation position of the laser beam 42 of the press-formed body 11, the metal powder 43 is further melted to form a build-up. The coaxial nozzle 45 relatively moves in the processing direction (the direction of the arrow 51). As a result, a molten layer 47 in which the metal powder 43 and the base material are melted and solidified is formed on the surface of the press molded body 11, and the metal powder 43 is melted and solidified and built up to a predetermined thickness (for example, a thickness A cladding layer 48 having a thickness of about 2 mm to 5 mm is formed. Therefore, the pair of vertical wall reinforcing portions 12 and the pair of connecting wall reinforcing portions 13 formed by the cladding layer 48 are entirely metal on the surfaces of the vertical wall inner walls 15A and 15B and the connecting wall inner wall 21 of the press-formed body 11. are spliced.

Next, for Comparative Example 1 using the conventional vehicle structural member 55 shown in FIG. 12 and Invention Example 1 using the vehicle structural member 1 according to the present embodiment shown in FIG. The results of the test (see FIG. 7) will be described. First, Comparative Example 1 using a conventional vehicle structural member 55 will be described with reference to FIG. 12 . In the description of the vehicle structural member 55, the same reference numerals as those of the vehicle structural member 1 shown in FIGS.

As shown in FIG. 12 , in a conventional vehicle structural member 55 constituting Comparative Example 1, a reinforcing member 56 press-formed into a shallow groove-like cross-sectional shape is positioned substantially inside a connecting wall 11C of the press-formed body 11 . They are welded by spot welding 57 so as to cover the entire surface and about 1/2 of the inner surfaces of the pair of vertical walls 11A and 11B on the connecting wall 11C side. The length of the reinforcing member 56 is equal to the distance between both ends of the vertical wall reinforcing portion 12 in the longitudinal direction of the press-formed body 11 shown in FIG. The reinforcing member 56 is arranged so as to cover the region of the press-formed body 11 where the vertical wall reinforcing portion 12 is provided.

In addition, a flat plate-like inner panel 58 having a long rectangular shape in plan view is overlapped along the longitudinal direction of the press-formed body 11 so as to cover the pair of flange portions 11D and 11E, and is welded by spot welding 59 to form a substantially rectangular panel. It constitutes a closed cross-section of the shape. The flat inner panel 58 is formed to have the same length as the press-formed body 11, and has a width substantially equal to the distance between the outer edges of the pair of flange portions 11D and 11E of the press-formed body 11. there is Further, each spot welding 57, 59 may be performed by spot welding, arc welding, laser welding, or any other suitable method. In addition, in FIG. 12, the welding points are indicated by x marks.

As shown in FIG. 13, in the present invention example 1, a flat plate-shaped inner panel 58 having a rectangular shape in a plan view is overlapped along the longitudinal direction of the vehicle structural member 1 so as to cover the pair of flange portions 11D and 11E. are welded by spot welding 59 to form a substantially rectangular closed cross section. Accordingly, a pair of vertical wall reinforcing portions 12 and a pair of connecting wall reinforcing portions 13 are formed inside the pair of vertical walls 11A and 11B and the connecting wall 11C of the press molded body 11 by laser clad processing. In addition, in FIG. 13, the welding points are indicated by x marks.

Test conditions for the three-point bending strength test will be described. The press-formed body 11 and the inner panel 58 are high-strength steel plates having a plate thickness of 1.8 mm and a tensile strength of 1470 MPa. The reinforcing member 56 is a high-tensile steel plate having a plate thickness of 3.0 mm and a tensile strength of 590 MPa. The pair of vertical wall reinforcements 12 and the pair of connection wall reinforcements 13 are formed with a thickness of 3.0 mm by laser clad processing.

The spot welds 57 were welded at intervals of 45 mm in the longitudinal direction. The spot welds 59 were welded at intervals of 40 mm in the longitudinal direction. The length of the press molded body 11 and the inner panel 58 is 600 mm. The length of the reinforcing member 56 and the distance between the longitudinal ends of the vertical wall reinforcing portion 12 are 500 mm. In the three-point bending strength test, the inner panel 58 side was horizontally supported by a support member having a semicircular cross section with a support point interval of 500 mm (see FIG. 7). Then, a downward load of 30 kN was applied to the central position in the longitudinal direction of the press molded body 11 by an impactor (not shown) having a semicircular cross section with a radius of 90 mm and being longer than the width of the connecting wall 11C (see FIG. 7).

As shown in FIG. 14, the weight of Comparative Example 1 subjected to the three-point bending strength test was 1420 grams, and the weight of Inventive Example 1 was 670 grams. In other words, the weight of "Invention Example 1" having a pair of vertical wall reinforcing portions 12 and a pair of connecting wall reinforcing portions 13 formed by laser clad processing is reduced by the reinforcing member 56 press-molded into a shallow groove-like cross-sectional shape. It was possible to reduce the weight by about 53% with respect to the weight of "Comparative Example 1" having.

Furthermore, the amount of displacement at the central position in the longitudinal direction of the press-formed body 11 was 5.27 mm in "Invention Example 1" and 7.12 mm in "Comparative Example 1", and the bending rigidity of "Invention Example 1" was was 5690 N/mm, and the flexural rigidity of "Comparative Example 1" was 4210 N/mm. That is, the flexural rigidity of "Example 1 of the present invention" was able to be increased by about 26% with respect to the flexural rigidity of "Comparative example 1".

As described in detail above, in the vehicle structural member 1 according to the present embodiment, the bending load acts on the central portion in the longitudinal direction of the connecting wall 11C by forming each strip-shaped vertical wall reinforcing portion 12 in an arch shape. It is possible to ensure the bending rigidity at the time. Moreover, weight reduction can be achieved by forming each vertical wall reinforcement part 12 in strip|belt shape.

In addition, by forming a pair of connecting wall reinforcing portions 13 in a belt shape at the central portion in the longitudinal direction of both side edges of the inner wall 21 of the connecting wall 21, bending rigidity is ensured when a bending load acts on the central portion in the longitudinal direction of the connecting wall 11C. can do. Moreover, since a pair of connecting wall reinforcement part 13 is spaced apart and provided in the width direction of 11 C of connecting walls, further weight reduction can be achieved. Furthermore, since the vertical wall reinforcing portions 12 and the connecting wall reinforcing portions 13 formed by laser clad processing are metal-joined to the vertical wall inner walls 15A and 15B and the connecting wall inner wall 21 on the entire surface, the vehicle structural member 1 It is possible to improve the bending rigidity of.

Further, since each of the pair of connecting wall reinforcing portions 13 has the first hole portion 22, further weight reduction can be achieved. Moreover, since each vertical wall reinforcing portion 12 has a pair of second hole portions 19, further weight reduction can be achieved. In addition, since the bending load is bifurcated at the periphery of the second hole 19 and transmitted to the arch-shaped end, deformation due to the bending load can be suppressed.

It should be noted that the present invention is not limited to the above embodiments, and various improvements, modifications, additions, and deletions are possible without departing from the scope of the present invention. For example, it may be as follows. In the following description, the same reference numerals as those of the vehicle structural member 1 according to the above-described embodiment indicate the same or corresponding parts as the vehicle structural member 1 according to the above-described embodiment.

(A) For example, instead of the vertical wall reinforcing portion 12, a vertical wall reinforcing portion 71 shown in FIG. 15 may be formed on each of the vertical wall inner walls 15A and 15B by laser clad processing. As shown in FIG. 15, the shape of the vertical wall reinforcing portion 71 viewed from the front side is the same shape as the vertical wall reinforcing portion 12 of the above-described embodiment. However, in the vertical wall reinforcing portion 71, as shown in the X1-X1 to X7-X7 arrow cross-sectional views, the thickness of the clad layer gradually decreases from the longitudinal center position toward the longitudinal end portions. You can also fill it with meat.

For example, the thickness of the cladding layer at the longitudinal central position (X4-X4 arrow cross section) of the vertical wall reinforcing portion 71 is about 4 mm to 5 mm, and the longitudinal direction both ends of the vertical wall reinforcing portion 71 (X1-X1 arrow The clad layer may be built up to a thickness of about 1.5 mm to 2.5 mm in the view section and the X7-X7 arrow view section. As a result, the vertical wall reinforcing portion 71 is built up so that the thickness of the central portion of the arch shape is greater than the thickness of both ends in the longitudinal direction, so that the bending rigidity can be further improved. .

(B) Further, for example, the pair of connecting wall reinforcing portions 13 may also be built up by laser clad processing so that the thickness of the clad layer gradually decreases from the longitudinal center position toward the longitudinal end portions. good. For example, the thickness of the clad layer at the central position in the longitudinal direction of the connecting wall reinforcing portion 13 is about 4 mm to 5 mm, and the thickness of the clad layer at both ends in the longitudinal direction of the connecting wall reinforcing portion 13 is about 2.5 mm to about 2.5 mm. You may pile up so that it may become 3.0 mm. As a result, the thickness of the central portion of the pair of connecting wall reinforcing portions 13 is built up so as to be larger than the thickness of both ends in the longitudinal direction, so that the bending rigidity can be further improved.

(C) Further, the first to fifth inventions have the following effects. For example, according to the vehicle structural member according to the first aspect of the present invention, by forming the band-shaped vertical wall reinforcing portion in an arch shape, bending rigidity is ensured when a bending load acts on the central portion in the longitudinal direction of the connecting wall. be able to. Moreover, weight reduction can be achieved by forming a vertical-wall reinforcement part in strip|belt shape. Furthermore, since the vertical wall reinforcing portion is formed by metal-bonding the reinforcing material to the inner wall of the vertical wall by laser clad processing, bending rigidity can be improved.

Further, according to the structural member for a vehicle according to the second aspect of the invention, the pair of connecting wall reinforcing portions are formed in a strip shape at the central portion in the longitudinal direction of both side edges of the inner wall of the connecting wall, so that the connecting wall is bent in the central portion in the longitudinal direction. Bending rigidity can be ensured when a load is applied. Moreover, since a pair of connection wall reinforcement part is spaced apart and provided in the width direction of a connection wall, the further weight reduction can be achieved. Furthermore, since the connecting wall reinforcing portion is formed by metal-bonding the reinforcing material to the inner wall of the connecting wall by laser clad processing, bending rigidity can be improved.

Moreover, according to the structural member for a vehicle according to the third aspect of the invention, each of the pair of connecting wall reinforcing portions has the first hole, so that further weight reduction can be achieved. Further, according to the structural member for a vehicle according to the fourth aspect of the invention, the vertical wall reinforcing portion has the pair of second hole portions, so that further weight reduction can be achieved. Moreover, since the bending load is bifurcated at the periphery of the second hole and transmitted to the arch-shaped end, deformation due to the bending load can be suppressed. In addition, according to the vehicle structural member according to the fifth aspect of the invention, the vertical wall reinforcing portion is formed so that the thickness of the arch-shaped central portion is larger than the thickness of the longitudinal end portions, so that bending is possible. Further improvement in rigidity can be achieved.

1 Structural Member for Vehicle 11 Press Formed Body 11A, 11B, 27A, 27B Vertical Wall 11C, 27C Connection Wall 11D, 11E, 27D, 27E Flange Section 12 Vertical Wall Reinforcement Section 13 Connection Wall Reinforcement Section 15A, 15B Vertical Wall Inner Wall 19 No. 2 holes 21 inner wall of connecting wall 22 first hole 41 laser clad device 42 laser beam 43 metal powder 45 coaxial nozzle

Claims (5)

A structural member for a vehicle comprising a pair of vertical walls facing each other and a connecting wall connecting the pair of vertical walls,
The pair of vertical walls are
In each of the inner walls of the vertical walls facing each other, the reinforcing material extends from the longitudinal central portion of the inner edge on the side of the connecting wall toward the longitudinal ends of the outer edge on the outer side with respect to the connecting wall. Having a strip-shaped vertical wall reinforcement part provided by laser cladding so as to extend in an arch shape,
Structural members for vehicles. The structural member for a vehicle according to claim 1,
The connecting wall is
In the inner wall of the connecting wall that is continuous with the inner wall of the vertical wall, the reinforcing material is provided by laser cladding so as to extend in a belt shape of a predetermined length in the longitudinal direction from the position facing the top of the vertical wall reinforcing portion on each side edge. a pair of connecting wall reinforcements,
Structural members for vehicles. The vehicle structural member according to claim 2,
The connecting wall reinforcing portion is
A first hole formed to extend from the longitudinal center to both sides in the longitudinal direction at a predetermined position symmetrical with respect to the center in the width direction of the inner wall of the connecting wall,
Structural members for vehicles. The vehicle structural member according to any one of claims 1 to 3,
The vertical wall reinforcing portion is
A pair of second holes formed in a shape symmetrical with respect to the longitudinal central portion of the inner wall of the vertical wall and formed at predetermined positions symmetrical with respect to the longitudinal central portion,
Structural members for vehicles. The vehicle structural member according to any one of claims 1 to 4,
The vertical wall reinforcing portion is
The thickness of the central portion in the longitudinal direction extending in the arch shape is formed so as to be larger than the thickness of both longitudinal end portions.
Structural members for vehicles.

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