JP2012236524A - Vehicular frame structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular frame structure in which an increase in weight of a frame is suppressed and furthermore the bending strength of the frame is increased.SOLUTION: The frame 1 includes: a first face part 11 to which a force in the compression direction is applied; a second face part 21 to which a force in the tensile direction is applied, both of the forces being applied when a load is applied to the frame from the outside; and third face parts 12, 22 which are positioned on both sides of the frame and between the first face part 11 and second face part 21 of the frame 1 and which form corner parts 1a, 1b between the first face part 11 and second face part 21, respectively. The corner parts 1a formed between the first face part 11 and third face parts 12, 22 are formed in curved line parts 1c, and parts adjacent to the curved line parts 1c on both-side third face parts 12, 22 are formed in straight line parts 12a, and the frame 1 includes a first connection part 30 connecting boundary parts 12b of the curved line parts 1c on both-side third face parts 12, 22 and the straight line parts 12a.

Description

  The present invention relates to a structure of a vehicle frame constituting a part of a vehicle body in a vehicle such as an automobile, and more particularly to a structure of a vehicle frame formed in a closed cross-sectional shape.

  As is well known, a vehicle frame (body frame) such as a pillar or a side sill constituting a part of a vehicle body in a vehicle such as an automobile is generally formed in a closed cross-sectional shape. In addition, the body frame is reinforced so that the flange joints on both sides are connected to each other inside the body frame formed in a closed cross-sectional shape by overlapping the flanges of two plate-shaped members formed in a cross-sectional hat shape. A member that is reinforced by adding a member is generally known (for example, see Patent Document 1).

JP 2003-95131 A

  However, when a reinforcing member is added and reinforced so that the flanges on both sides are connected to each other inside the body frame formed in a closed cross-sectional shape, the reinforcing member causes an increase in weight, so pillars, side sills, etc. In the body frame, how to reinforce while suppressing an increase in weight is an important issue.

  On the other hand, in the case of body frames such as pillars and side sills, for example, to ensure the safety of the occupant in the event of a side collision, the body frame should not be deformed to the inside of the vehicle even when an external load is applied to the body frame. Therefore, it is required to increase the bending strength of the body frame.

  When a load is applied to the vehicle body frame formed in a closed cross-sectional shape to bend and deform, the first surface portion to which a force in the compression direction acts when the load is applied is formed along the load input direction of the vehicle body frame. It is known that the inner surface is deformed inward, and the surface portion adjacent to the first surface portion swells to the outer side of the vehicle body frame to cause out-of-plane deformation.

  Therefore, in a vehicle body frame in which a load may be applied from the outside, the deformation of the surface portion adjacent to the first surface portion deformed in accordance with the bending deformation of the first surface portion toward the inward side of the vehicle body frame. If it can be suppressed, it is considered that the bending deformation of the entire body frame can be effectively suppressed, and the bending strength of the entire body frame can be increased.

  As described in Patent Document 1, by adding a reinforcing member so as to connect the flange portions on both sides to the inside of the body frame, the first inward side of the body frame when a load is applied from the outside. Although it is possible to suppress the outward deformation of the surface portion adjacent to the first surface portion that deforms due to the bending deformation of the surface portion, a further reduction in weight is required for a body frame that occupies a relatively large weight. Therefore, a body frame with high weight efficiency is desired.

  Then, an object of this invention is to provide the frame structure for vehicles which can improve the bending strength of a flame | frame, suppressing the increase in a weight.

  For this reason, the invention according to claim 1 of the present application is a vehicle frame structure that forms a part of a vehicle body and has a frame formed in a closed cross-sectional shape, and when the frame receives a load from the outside, A first surface portion on which a force in the compression direction acts; a second surface portion on which the force in the tensile direction acts on the first surface portion; and a first surface portion and a second surface portion of the frame; The corner portions on both sides formed between the first surface portion and the third surface portions on both sides, each having a third surface portion on both sides forming a corner portion between the first surface portion and the second surface portion, respectively. Each of which is formed by a curved portion extending in a curved shape in the cross section of the frame and a portion adjacent to the curved portion in the third surface portion is formed by a linear portion extending linearly in the cross section of the frame, The frame has the third surface portion on both sides. And a first connecting portion for connecting the boundary portion to each other between the line portion and the linear portion, it is obtained by it said.

  The invention according to claim 2 of the present application is the invention according to claim 1, wherein the first surface portion is formed by a linear portion in which a portion between the curved portions on both sides extends linearly, The one connecting portion is provided substantially parallel to the straight portion of the first surface portion.

  Furthermore, in the invention according to claim 3 of the present application, in the invention according to claim 1 or claim 2, the frame has a second connecting portion that connects the first surface portion and the first connecting portion, The second connecting portion extends in a direction substantially perpendicular to the first surface portion in a direction orthogonal to the longitudinal direction of the frame.

  Still further, the invention according to claim 4 of the present application is the invention according to claim 3, wherein the frame has the third surface portion side on both sides and the center side between the third surface portions on both sides of the first surface portion, respectively. It has the said 2nd connection part provided so that it might connect with a 1st connection part, It is characterized by the above-mentioned.

  Still further, the invention according to claim 5 of the present application is the invention according to claim 3, wherein the frame is provided so as to connect the third surface portions on both sides of the first surface portion to the first connecting portion. In addition, the second connecting portion is provided.

  Still further, in the invention according to claim 6 of the present application, in the invention according to claim 3, the second connecting portion has a central side between the third surface portions on both sides of the first surface portion as the first connecting portion. It has the said 2nd connection part provided so that it might connect, It is characterized by the above-mentioned.

  Furthermore, the invention according to claim 7 of the present application is the invention according to any one of claims 1 to 6, wherein the frame is positioned between the front and rear door openings provided on the side surface of the vehicle body. Thus, the center pillar extends in the vertical direction of the vehicle body.

  According to the vehicle frame structure according to claim 1 of the present application, the frame formed in the closed cross-sectional shape has a first surface portion on which a force in the compression direction acts when a load acts from the outside, and a force in the tension direction acts. And both corners formed between the first surface portion and the third surface portions on both sides. The second surface portion includes a second surface portion and a third surface portion on both sides positioned between the first surface portion and the second surface portion of the frame. Each part is formed by a curved part and a part adjacent to the curved part in the third surface part is formed by a straight part, and the frame connects the boundary part between the curved part and the straight part in the third surface part on both sides. It has one connecting part.

  Thus, when a load is applied from the outside, the third surface portion on both sides of the first surface portion swells outwardly and deforms with the deformation of the first surface portion toward the inward side of the frame. Since it can suppress effectively by the 1st connection part which connects the boundary part of the curved part and linear part in a 3 surface part, the bending strength of a flame | frame can be improved, suppressing the increase in a weight. In addition, when the first connecting portion is deformed to the inner side of the frame along with the deformation of the first surface portion toward the inner side of the frame, the first connecting portion causes the third surface portions on both sides to move into the inner side of the frame. Since it acts so that it may pull to the side, it can suppress that the 3rd surface part of both sides swells outward and deform | transforms, The said effect can be acquired effectively. Moreover, since weight reduction can be achieved, a fuel consumption can be improved and the energy saving effect can be heightened.

  According to the invention of claim 2 of the present application, the first surface portion is formed by a straight portion between the curved portions on both sides, and the first connecting portion is substantially parallel to the straight portion of the first surface portion. By being provided, the load acting on both sides of the first connecting portion when a load is applied from the outside can be made substantially equal, so that the deformation of the third surface portion on both sides to the outer side is more effectively suppressed. can do.

  Further, according to the invention of claim 3 of the present application, the frame has a second connecting portion that connects the first surface portion and the first connecting portion, and the second connecting portion is orthogonal to the longitudinal direction of the frame. In the direction to extend in the direction substantially perpendicular to the first surface portion, the first connection portion is moved inside the frame via the second connection portion with the deformation of the first surface portion toward the inner side of the frame. Therefore, the first connecting portion can act so as to pull the third surface portions on both sides toward the inward side of the frame, and the effect can be more effectively achieved.

  Still further, according to the invention according to claim 4 of the present application, the frame is connected to the first connection portion at the third surface portion side on both sides of the first surface portion and the center side between the third surface portions on both sides. By having the 2nd connection part provided, the said effect can be implement | achieved more concretely.

  Still further, according to the invention according to claim 5 of the present application, the frame has the second connection portion provided so as to connect the third surface portion sides on both sides of the first surface portion to the first connection portion, respectively. Therefore, the effect can be realized more specifically.

  Still further, according to the invention of claim 6 of the present application, the frame includes the second connecting portion provided so as to connect the center side between the third surface portions on both sides of the first surface portion with the first connecting portion. By having it, the effect can be realized more specifically.

  Furthermore, according to the invention of claim 7 of the present application, the frame is a center pillar that is positioned between the front and rear door openings provided on the side surface of the vehicle body and extends in the vertical direction of the vehicle body. It is possible to improve the bending strength of the center pillar while suppressing the increase. For example, it is possible to effectively suppress the center pillar from being bent and deformed when a load is applied to the center pillar from the outside, for example, in a side collision.

1 is a perspective view showing a vehicle body frame to which a vehicle frame structure according to a first embodiment of the present invention is applied. FIG. 2 is a cross-sectional view of the vehicle body frame taken along line Y2-Y2 in FIG. It is a graph which shows the relationship between the downward stroke of an indenter and the bending load about the said vehicle body frame. It is sectional drawing which shows the result of having carried out the simulation analysis of the bending deformation behavior of the said vehicle body frame. It is a figure which shows the analysis result of bending strength about the vehicle body frame whose curvature radius of an upper corner part is 15 mm. It is a graph which shows the analysis result of bending strength about the vehicle body frame whose curvature radius of an upper corner part is 15 mm. It is sectional drawing which shows the cross section of the vehicle body frame whose curvature radius of an upper corner part is 5 mm and 25 mm. It is a graph which shows the analysis result of bending strength about the body frame whose curvature radius of an upper corner part is 5 mm and 25 mm. It is sectional drawing which shows the modification of the vehicle body frame to which the vehicle frame structure which concerns on the 1st Embodiment of this invention is applied. It is sectional drawing which shows the vehicle body frame to which the frame structure for vehicles which concerns on the 2nd Embodiment of this invention is applied. It is a figure which shows the analysis result of bending strength about the said vehicle body frame whose curvature radius of an upper corner part is 15 mm. It is a perspective view which shows the vehicle body frame formed in the closed cross-sectional shape. It is explanatory drawing for demonstrating the simulation for analyzing the bending deformation behavior of a vehicle body frame. It is a perspective view which shows the result of having analyzed the bending deformation behavior of the vehicle body frame shown in FIG. It is sectional drawing which shows the bending part of the vehicle body frame in FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, terms that mean a specific direction such as “up”, “down”, “right”, “left” and other terms including those terms are used. In order to facilitate understanding of the referenced invention, the technical scope of the present invention is not limited by the meaning of these terms.

  In developing a vehicle frame structure that can improve the bending strength of a frame while suppressing an increase in weight in a vehicle frame structure having a frame formed in a closed cross-sectional shape, the inventors of the present application firstly close the frame. A simulation analysis by CAE (Computer Aided Engineering) was performed on the deformation behavior when the body frame was bent and deformed by inputting a bending load from the outside to the body frame formed in a cross-sectional shape.

  FIG. 12 is a perspective view showing a vehicle body frame formed in a closed cross-sectional shape. As shown in FIG. 12, flange portions 113 and 123 of two metal plate-like members 110 and 120 each having a bottom face portion 111 and 121, side surface portions 112 and 122, and flange portions 113 and 123 and having a cross-sectional hat shape. The vehicle body frame 101 formed in a closed cross-sectional shape by the first plate-like member 110 and the second plate-like member 120 by superimposing them on each other was used as an analysis model for simulation analysis.

  FIG. 13 is an explanatory diagram for explaining a simulation for analyzing the bending deformation behavior of the vehicle body frame, and FIG. 14 is a perspective view showing a result of simulation analysis of the bending deformation behavior of the vehicle body frame shown in FIG. 15 is a cross-sectional view showing a bent portion of the vehicle body frame in FIG. In FIG. 14, the indenter to which the load is applied is omitted, and the deformation amount of each part of the frame is represented by shades of color, and the larger the deformation amount, the darker the color. 14 and 15 show the progress of the bending deformation of the frame in the order of (a), (b), (c), and (d).

  As shown in FIG. 13 (a), a vehicle body frame 101 having a predetermined length X1 in a state where the bottom surface portion 111 of the first plate-like member 110 is on the upper side is set to a predetermined length shorter than the length X1. The center in the longitudinal direction of the bottom surface portion 111 of the first plate-like member 110 that is supported by the two fixing points 131 separated by the distance X2 and corresponding to the intermediate position between the two fixing points 131 is the upper surface portion of the body frame 101. The indenter 132 is lowered at a constant speed from above to the part P1, and a load F simulating a load input from the outside at the time of a side collision or the like is applied to the body frame 101 via the indenter 132, and the body frame 101 is bent and deformed. The behavior was investigated.

  When a bending load F acts on the vehicle body frame 101 from the outside, as shown in FIG. 13B, the vehicle body frame 101 is bent and deformed in a convex shape on the lower side, and the upper surface portion 111 is compressed from both ends in the longitudinal direction. , The compressive stress is generated, and the tensile force is generated from both ends in the longitudinal direction on the bottom surface portion 121 of the second plate-like member 120 which is the lower surface portion of the vehicle body frame 101. . Further, the side surface portion 112 of the first plate-shaped member 110 and the side surface portion 122 of the second plate-shaped member 120 which are the side surface portions on both sides of the body frame 101 are subjected to compressive stress on the upper surface portion 111 side from the neutral shaft 105. As a result, a tensile stress is generated on the lower surface 121 side from the neutral shaft 105.

  As shown in FIG. 14 and FIG. 15A, when the indenter 132 descends from above the vehicle body frame 101 and comes into contact with the vehicle body frame 101, stress starts to occur in the upper surface portion 111 and the lower surface portion 121 of the vehicle body frame 101. Then, as shown in FIGS. 14 and 15 (b), (c), and (d), as the descending stroke of the indenter 132 increases, the vehicle body frame 101 is curved and deformed in a convex shape downward, The body frame 101 is subjected to a compressive force on the upper surface 111 and a tensile force on the lower surface 121, and is bent and deformed from the central portion P1 to which the load F is applied.

  Further, as shown by an arrow d1 in FIG. 15B, the upper surface portion 111 of the vehicle body frame 101 is deformed inward of the vehicle body frame 101, and along with this deformation, it is shown by an arrow d2 in FIG. 15B. As described above, the side surface portions 112 and 122 adjacent to the upper surface portion 111 bulge outward in the orthogonal cross-sectional direction, which is a direction orthogonal to the longitudinal direction of the body frame 101, to cause out-of-plane deformation.

  Specifically, the side portions 112 and 122 of the body frame 101 located on the right side in FIG. 15 bulge to the right side, and the side portions 112 and 122 of the body frame 101 located on the left side in FIG. As shown by a deformed portion α in FIG. 14, a corner portion 101 a formed between the upper surface portion 111 and the side surface portions 112 and 122 of the body frame 101, specifically, the side surface portion 112 of the first plate-like member 110. As a result, a portion with a large amount of deformation is generated, and the body frame 101 is bent and deformed.

  From this simulation analysis result, when the load F acts on the vehicle body frame 101 formed in a closed cross-sectional shape from the outside to bend and deform, the upper surface portion 111 on which the force in the compression direction acts when the load F acts is the load. It deforms inward of the body frame 101 along the input direction of F, and in accordance with this deformation, the side surface portions 112 and 122 adjacent to the upper surface portion 111 bulge outwardly of the body frame 101 to cause out-of-plane deformation. It can be seen that the body frame 101 is bent and deformed.

  Therefore, when a load is applied to the vehicle body frame 101 from the outside, an angle is formed between the upper surface portion 111 on which the force in the compression direction acts and the lower surface portion 121 on which the force in the tensile direction acts. It is considered that the bending strength of the vehicle body frame 101 can be effectively increased if the outward deformation of the side surface portions 112 and 122 on both sides forming the portion 101a can be effectively suppressed.

Hereinafter, a vehicle frame structure according to an embodiment of the present invention will be described.
FIG. 1 is a perspective view showing a vehicle body frame to which the vehicle frame structure according to the first embodiment of the present invention is applied, and FIG. 2 is a cross-sectional view of the vehicle body frame taken along line Y2-Y2 in FIG. is there.

  As shown in FIGS. 1 and 2, the vehicle body frame 1 to which the vehicle frame structure according to the first embodiment of the present invention is applied is positioned, for example, between front and rear door openings provided on the side surface of the vehicle body. It can be applied to center pillars that extend in the vertical direction of the vehicle body and side sills that extend in the longitudinal direction of the vehicle body at the lower part of the vehicle body. Metal plate materials such as steel plates are pressed into a cross-sectional hat shape. A first plate member 10 and a second plate member 20 obtained by processing are provided.

  The first and second plate-like members 10 and 20 have a bottom surface portions 11 and 21 formed in a substantially planar shape, and have a predetermined angle from the bottom surface portions 11 and 21 on both sides of the bottom surface portions 11 and 21. The side portions 12 and 22 are formed so as to extend in a substantially flat shape, and flange portions 13 and 23 extending outward from the side portions 12 and 22 in parallel with the bottom surface portions 11 and 22 are formed in a hat shape in cross section. .

  And the 1st plate-shaped member 10 and the 2nd plate-shaped member 20 pile up the flange part 13 of the 1st plate-shaped member 10, and the flange part 23 of the 2nd plate-shaped member 20, and are welded etc. The bottom surface portion 11 of the first plate member 10 and the bottom surface portion 21 of the second plate member 20 are opposed to each other and the bottom surface portion 11 of the first plate member 10 and the second plate are joined together. The side surface portions 12 on both sides of the first plate-like member 10 and the side surface portions 22 on both sides of the second plate-like member 20 that are positioned between the bottom surface portion 21 of the shape-like member 20 are opposed to each other. It is formed in a closed cross section.

  As shown in FIG. 2, in the vehicle body frame 1, corner portions 1 a are formed between the bottom surface portion 11 of the first plate-like member 10 and the side surface portions 12 on both sides, and the corner portions 1 a are formed on the vehicle body frame 1. It is formed of a curved portion 1c that extends in a curved shape in a cross-sectional direction that is a direction orthogonal to the longitudinal direction of the first curved portion and has a predetermined radius of curvature. Further, the corner portions 1b formed between the bottom surface portion 21 and the side surface portions 22 on both sides of the second plate-like member 20 also extend in a curved shape in the orthogonal cross-section direction, and have a predetermined radius of curvature. It is formed with a curved part having.

  In the vehicle body frame 1, portions of the side surface portions 12 on both sides of the first plate-like member 10 that are adjacent to the curved portion 1 c are formed by straight portions 12 a extending linearly in the orthogonal cross-sectional direction, and A portion between the curved portions 1c on both sides of the bottom surface portion 11 of one plate-like member 10 is formed by a straight portion 11a extending linearly in the orthogonal cross-sectional direction.

  In the present embodiment, the side surface portions 12 on both sides of the first plate member 10 are connected between the bottom surface portion 11 of the first plate member 10 and the bottom surface portion 21 of the second plate member 20. A flat first reinforcing member 30 is attached. The first reinforcing member 30 is formed of a metal plate-like material such as a steel plate, extends along the longitudinal direction of the vehicle body frame 1, and is a curved portion in the side surface portions 12 on both sides of the first plate-like member 10. It joins to the side part 12 of both sides by welding etc. so that the boundary part 12b of 1c and the linear part 12a may be connected.

  In the vehicle body frame 1, the corner portions 1 a on both sides between the bottom surface portion 11 of the first plate-like member 10 and the side surface portions 12 on both sides are formed by curved portions 1 c each having a predetermined radius of curvature and the curved portion 1 c. The first reinforcing member 30 is provided substantially in parallel with the straight portion 11 a of the bottom surface portion 11 of the first plate-like member 10.

  The vehicle body frame 1 configured as described above is arranged so that the bottom surface portion 11 of the first plate-like member 10 faces in a direction in which a bending load is assumed to be input from the outside. Thereby, when a bending load is applied from the outside, a force in the compression direction acts on the bottom surface portion 11 of the first plate-like member 10, and a force in the tensile direction acts on the bottom surface portion 21 of the second plate-like member 20. Will be.

  As described above, the vehicle body frame 1 according to the first embodiment of the present invention is opposed to the first surface portion 11 on which the force in the compression direction acts when a load is applied from the outside, and the first surface portion 11 in the tensile direction. A second surface portion 21 on which a force acts, and third surface portions 12 and 22 on both sides located between the first surface portion 11 and the second surface portion 21 of the vehicle body frame 1, A corner portion 1a on both sides formed between the three surface portions 12 and 22 is formed by a curved portion 1c, and a portion adjacent to the curved portion 1c of the third surface portions 12 and 22 is formed by a straight portion 12a. 1 has the 1st connection part 30 which connects the boundary part 12b of the curved part 1c and the linear part 12a in the 3rd surface parts 12 and 22 of both sides.

  In the present embodiment, similarly to the vehicle body frame 101 shown in FIG. 12, the bending load when the load is applied from the outside through the indenter is analyzed by simulation analysis for the vehicle body frame 1 according to the first embodiment of the present invention. evaluated. The body frame 1 was evaluated using the same body frame 101 as that shown in FIG. 12 except that the first reinforcing member 30 was added.

  Specifically, for the vehicle body frame 1, the first plate member 10 is a 980 MPa class high-tensile steel plate with a plate thickness of 1.8 mm, and the second plate member 20 is 590 MPa with a plate thickness of 1.0 mm. The first reinforcing member 30 is a 980 MPa class high-tensile steel plate having a thickness of 1.0 mm, and the bottom surface portion 11 of the first plate member 10 and the bottom surface portion of the second plate member 20 are used. The distance H1 of 21 is 88 mm, the length W1 of the bottom surface portion 11 of the first plate member 10 in the orthogonal cross-sectional direction is 92.5 mm, and the bottom surface portion 11 of the first plate member 10 and the side surface portions on both sides. The angle θ between the first plate member 10 and the flange portion 13 is 67 mm. The angle θ between the first plate member 10 and the flange portion 13 is 67 mm. The bottom surface portion 11 of the plate-like member 10 and the first The distance H3 of the reinforcing member 30 were evaluated those with 10 mm. In addition, in the bottom face part 11 of the 1st plate-shaped member 10, the length in the said orthogonal cross-section direction of the linear part 11a is 70 mm.

  FIG. 3 is a graph showing the relationship between the descending stroke of the indenter and the bending load for the body frame. In FIG. 3, the horizontal axis represents the descending stroke from the position where the indenter contacts the body frame, and the reaction force against the load F is shown in FIG. The bending load is shown on the horizontal axis, the analysis result of the vehicle body frame 1 shown in FIG. 1 is represented by a solid line, and the analysis result of the vehicle body frame 101 shown in FIG. 12 is represented by a broken line. FIG. 4 is a cross-sectional view showing the result of simulation analysis of the bending deformation behavior of the vehicle body frame. In the cross section of the bent portion, the progress of bending deformation of the vehicle body frame 1 shown in FIG. It is expressed in the order of b), (c), and (d).

  As shown by the broken line in FIG. 3, in the vehicle body frame 101 shown in FIG. 12, the maximum value of the bending load when a load is applied from the outside is about 22.5 kN, whereas as shown by the solid line in FIG. In the vehicle body frame 1 provided with the first reinforcing members 30 that connect the boundary portions 12b between the curved portions 1c and the straight portions 12a in the side surface portions 12 of the first plate-like members 10 on both sides, the maximum bending load is provided. In the vehicle body frame 1 having a value of about 40 kN and the first reinforcing member 30 added, the maximum bending strength can be improved as compared with the vehicle body frame 101 in which the first reinforcing member 30 is not provided.

  As shown in FIG. 4A, also for the vehicle body frame 1, when the indenter 132 descends from above the vehicle body frame 1 and comes into contact with the vehicle body frame 1, the bottom surface portion (first surface portion) of the first plate member 10. 11 and the bottom surface portion (second surface portion) 21 of the second plate-like member 20 begins to generate stress, and as the descending stroke of the indenter 132 increases, the vehicle body frame 1 is curved and deformed downward in a convex shape, In the body frame 1, a force in the compression direction acts on the first surface portion 11, and a force in the tensile direction acts on the second surface portion 12.

  As for the vehicle body frame 1, as shown in FIGS. 4B, 4 </ b> C, and 4 </ b> D, as the descending stroke of the indenter 132 increases, the first surface portion 11 moves toward the inward side of the vehicle body frame 1. Although deformed, the side surface portion (third surface portion) 12 of the first plate-like member 10 adjacent to the first surface portion 11 and the side surface portion (third surface portion) 22 of the second plate-like member 20 are the body frame 1. In the orthogonal cross-sectional direction, which is a direction orthogonal to the longitudinal direction, the bulging outward is suppressed from causing out-of-plane deformation.

  As described above, in the body frame 1, when a load is applied from the outside, the third surface portions 12 and 22 on both sides of the first surface portion 11 are externally moved along with the deformation of the first surface portion 11 toward the inward side of the body frame 1. Since it can be effectively suppressed by the first connecting portion 30 that connects the boundary portions 12b between the curved portion 1c and the linear portion 12a in the third surface portions 11 and 12 on both sides, the first connecting portion 30 that swells and deforms in the lateral direction can be effectively suppressed. The bending strength of the frame can be improved while suppressing an increase in weight. Further, when the first connecting portion 30 is deformed inward of the body frame 1 in accordance with the deformation of the first surface portion 11 toward the inward side of the body frame 1, the first connecting portion 30 is disposed on both sides. Since it acts so that the 3rd surface parts 11 and 12 may be pulled to the inward side of body frame 1, it can control that the 3rd surface parts 11 and 12 of both sides swell and change outside, and the above-mentioned effect is obtained. It can be obtained effectively.

  In the present embodiment, the position of the reinforcing member 30 and the weight efficiency of the bending strength in the case of adding the reinforcing member 30 to the inside of the vehicle body frame 1, specifically, the vehicle body frame 101 (comparative example) shown in FIG. The relationship between the maximum bending load per unit weight and the ratio of the maximum bending load per unit weight of each body frame was investigated.

  FIG. 5 is a diagram showing an analysis result of bending strength for a vehicle body frame having a curvature radius of 15 mm at the upper corner portion, and shows an analysis result of a vehicle body frame having a curvature radius of the curved portion 1c of the corner portion 1a of 15 mm. ing. As shown in FIG. 5, the maximum bending load is analyzed for each of the first reinforcing members 30 attached to the inside of the vehicle body frame 1 separated from the bottom surface portion 11 of the first plate-like member 10 by a predetermined distance, The ratio of the maximum bending load per unit weight relative to the comparative example was evaluated.

  Specifically, the separation distance H3 between the bottom surface portion 11 of the first plate-like member 10 and the first reinforcing member 30 as the position of the first reinforcing member 30 is 0 mm, 5 mm, 10 mm, 17 mm, 37 mm, and 67 mm. These were evaluated as Sample 1A, Sample 1B, Sample 1C, Sample 1D, Sample 1E, and Sample 1F, respectively. The sample 1C is the body frame 1 shown in FIG. 1 in which the first reinforcing member 30 is provided so as to connect the boundary portions 12 between the curved portion 1c and the straight portion 12a. A comparative example is shown in FIG. The vehicle body frame 101 shown in FIG.

  FIG. 6 is a graph showing a bending strength analysis result for a vehicle body frame having an upper corner radius of curvature of 15 mm. In FIG. 6, the first plate member 10 is positioned as the position of the first reinforcing member 30 in FIG. Sample 1A, sample 1B, sample 1C, shown in FIG. 5, with the horizontal axis the separation distance H3 between the bottom surface portion 11 and the first reinforcing member 30 and the vertical axis the ratio of the maximum bending load per unit weight relative to the comparative example. Samples 1D, 1E, and 1F are plotted.

  As shown in FIGS. 5 and 6, the weight efficiency of the bending strength of the vehicle body frame is such that the position of the first reinforcing member 30 is 0 mm, and the first reinforcing member 30 is the boundary portion 12b between the curved portion 1c and the straight portion 12a. It becomes higher as it increases to 10 mm, which is the position where the two are connected, and decreases as the first reinforcing member 30 becomes larger from 10 mm, which is the position where the boundary portion 12b between the curved portion 1c and the straight portion 12a is connected. I understand.

  As described above, in the vehicle body frame 1 in which the first reinforcing member 30 is added to the inside of the vehicle body frame 1, the reinforcing member 30 is provided at a position where the boundary portion 12b between the curved portion 1c and the straight portion 12a is connected. The weight efficiency for the improvement of bending strength is the largest, and the position where the reinforcing member 30 is connected to the boundary portion 12b between the curved portion 1c and the straight portion 12a and the vicinity thereof, specifically, the position of the reinforcing member 30 is about It can be seen that when the thickness is 4 mm to about 25 mm, the weight efficiency of the bending strength is larger than that in the comparative example.

  In the present embodiment, the vehicle body frame in which the radius of curvature of the curved portion 1c of the corner portion 1a is 5 mm and 25 mm was also analyzed. FIG. 7 is a cross-sectional view showing a cross section of a vehicle body frame in which the curvature radius of the upper corner is 5 mm and 25 mm. As shown in FIG. 7 (a), a vehicle body frame 41 configured in the same manner except that the curvature radius of the vehicle body frame 1 and the curved portion 41c shown in FIG. 1 is 5 mm, and as shown in FIG. 7 (b). The first reinforcing member attached to the inside of the vehicle body frames 41 and 51 is similarly applied to the vehicle body frame 51 having the same configuration except that the curvature radius of the vehicle body frame 1 and the curved portion 51c shown in FIG. 1 is 25 mm. 30 was analyzed for the maximum bending load of the first plate-like member 10 separated from the bottom surface portion 11 by a predetermined distance, and the ratio of the maximum bending load per unit weight relative to the comparative example was evaluated. In FIG. 7, the same components as those of the vehicle body frame 1 shown in FIG.

  7 (a) and 7 (b), the vehicle body frames 41 and 51 are provided so that the first reinforcing member 30 connects the boundary portions 12b between the curved portions 41c and 51c and the straight portion 12a. As shown, for the body frame 41, in addition to the case where the position of the first reinforcing member 30 shown in FIG. 7A is 4.5 mm, the position of the first reinforcing member 30 is 0 mm, 19 mm, The body frame 51 was evaluated. For the body frame 51, in addition to the case where the position of the first reinforcing member 30 shown in FIG. 7B is 18 mm, the position of the first reinforcing member 30 is set to 0 mm, 4 mm. Evaluations were made for 7 mm and 39 mm.

  FIG. 8 is a graph showing the analysis result of the bending strength for the vehicle body frame having the curvature radius of the upper corner portion of 5 mm and 25 mm. In FIG. 8, the position of the first reinforcing member 30, that is, the first plate-like member is shown. The distance H3 between the bottom surface portion 10 and the first reinforcing member 30 is indicated on the horizontal axis, the ratio of the maximum bending load per unit weight relative to the comparative example is indicated on the vertical axis, and the radius of curvature of the curved portion 41c of the corner portion 1a is displayed. An analysis result of the vehicle body frame 41 having a radius of 5 mm is indicated by a solid line, and an analysis result of the vehicle body frame 51 in which the curvature radius of the curved portion 51c of the corner portion 1a is 25 mm is indicated by an alternate long and short dash line.

  As shown in FIG. 8, the weight efficiency of the bending strength of the vehicle body frame 41 is also curved from 0 mm at the position of the first reinforcing member 30 for the vehicle body frame 41 in which the curvature radius of the curved portion 41c of the corner portion 1a is 5 mm. As the position of the first reinforcing member 30 increases from 4.5 mm, the height decreases as the height increases to 4.5 mm, which is a position that connects the boundary portions 12b between the portion 41c and the straight portion 12a. When the reinforcing member 30 is provided at a position where the boundary portion 12b between the curved portion 41c and the straight portion 12a is connected, the weight efficiency for the improvement of the bending strength is greatest, and the position of the first reinforcing member 30 is from 0 mm to about 34 mm. At some point, it can be seen that the weight efficiency of bending strength is greater than in the comparative example.

  Also for the vehicle body frame 51 in which the radius of curvature of the curved portion 51c of the corner portion 1a is 25 mm, the weight efficiency of the bending strength of the vehicle body frame 51 is such that the position of the first reinforcing member 30 is 0 mm from the curved portion 51c and the straight portion 12a. As the position of the first reinforcing member 30 increases from 18 mm, the first reinforcing member 30 becomes straight with the curved portion 51c. When the boundary portion 12b with the portion 12a is provided at a position where the boundary portions 12b are connected to each other, the weight efficiency for improving the bending strength is greatest, and the weight efficiency of the bending strength when the position of the first reinforcing member 30 is about 3 mm to about 37 mm. It can be seen that becomes larger than that of the comparative example.

  Thus, between the 1st surface part 11 to which the force of a compression direction acts when the load acts from the outside, the 2nd surface part 21 to which the force of a tension direction acts, between the 1st surface part 11 and the 2nd surface part 21 It has the 3rd surface parts 12 and 22 of the both sides which are located, and the corner | angular part 1a of the both sides formed between the 1st surface part 11 and the 3rd surface parts 12 and 22 of both sides is formed by the curved part 1c, and is 1st. In the vehicle body frame in which the portion adjacent to the curved portion 1c of the three surface portions 12 and 22 is formed by the straight portion 12a, the boundary portion 12b between the curved portion 1c and the straight portion 12a in the third surface portions 12 and 22 on both sides is connected. By providing the first connecting portion 30, it is possible to improve the bending strength of the frame while suppressing an increase in weight. Further, even when the first connecting portion 30 is provided so as to connect adjacent portions of the boundary portion 12b between the curved portion 1c and the straight portion 12a in the third surface portions 12 and 22 on both sides, an increase in weight is suppressed. In addition, the bending strength of the frame can be improved. Moreover, since weight reduction can be achieved, a fuel consumption can be improved and the energy saving effect can be heightened.

  In addition, the first surface portion 11 is formed by a straight portion 11 a between the curved portions 1 c on both sides, and the first connecting portion 30 is provided substantially parallel to the straight portion 11 a of the first surface portion 11. Since the load acting on both sides of the first connecting portion 30 when a load is applied from the outside can be made substantially equal, the outward deformation of the third surface portions 12 and 22 on both sides can be more effectively suppressed. Can do.

  In the above-described embodiment, in the vehicle body frame 1, the first reinforcing member 30 is provided substantially parallel to the bottom surface portion 11 of the first plate member 10, and the first connecting portion 30 is the straight portion 11 a of the first surface portion 11. The first connecting portion 30 has a central side between the third surface portions 12 and 22 on both sides of the first surface portion 11 side or the second surface portion 22 and the second surface portions 22 and 22 side. You may make it bend | fold to the 2 surface part 21 side.

  FIG. 9 is a cross-sectional view showing a modified example of the vehicle body frame to which the vehicle frame structure according to the first embodiment of the present invention is applied. As shown in FIG. 9A, the first reinforcing member 60 attached to the inside of the vehicle body frame 61 is set so that the center side between the side portions 12 on both sides of the first plate member 10 is the side portions 12 on both sides. 9 may be bent so as to protrude toward the bottom surface portion 11 of the first plate-like member 10 as shown in FIG. The first reinforcing member 70 is formed on the side of the bottom surface portion 21 of the second plate-shaped member 20 by comparing the center side between the side surface portions 12 on both sides of the first plate-shaped member 10 with the side surface portions 12 on both sides. You may make it bend so that it may protrude. In FIG. 9, the same components as those of the vehicle body frame 1 shown in FIG.

  In vehicle body frames 61 and 71 in which the curvature radius of the curved portion 1c of the corner portion 1a is 15 mm and the first reinforcing members 60 and 70 are provided so as to connect the boundary portions 12b between the curved portion 1c and the straight portion 12a. 9 (a) and 9 (b), the center side between the side portions 12 on both sides of the first plate-like member 10 is set to the side portions 12 on both sides of the first reinforcing member 60 or 70. When analyzing the weight efficiency of the bending strength even when bent so as to protrude to the bottom surface portion 11 side of the first plate member 10 or the bottom surface portion 21 side of the second plate member 20 compared to the side, As shown in FIG. 9A, the weight efficiency of the bending strength is such that the center portion of the first reinforcing member 60 is bent so as to protrude 5.0 mm toward the bottom surface portion 11 side of the first plate-like member 10. In this case, the first reinforcing portion is 1.17 as shown in FIG. When the center portion of 70 is bent so as to protrude 5.0 mm toward the bottom surface portion 21 side of the second plate-like member 20, it is 1.23. In this case as well, the weight efficiency of bending strength is a comparative example. Compared with the case of, it can improve.

  In the embodiment described above, the corner portion 1a formed between the bottom surface portion 11 of the first plate-like member 10 of the body frame 1 and the side surface portions 12 on both sides of the first plate-like member 10 has a predetermined shape. Although it is formed by the curved portion 1c having the curvature radius r, it is not limited to this, and it extends in other curved shapes that are convexly curved outwardly of the body frame 1 according to the desired shape. You may make it form in the curve part to do.

Next, a vehicle frame structure according to the second embodiment of the present invention will be described.
FIG. 10 is a cross-sectional view showing a vehicle body frame to which a vehicle frame structure according to the second embodiment of the present invention is applied. The vehicle body frame 81 to which the vehicle frame structure according to the second embodiment of the present invention is applied is the first plate member 10 in the vehicle body frame 1 to which the vehicle frame structure according to the first embodiment of the present invention is applied. Since the second reinforcing member 90 for connecting the bottom surface portion 11 and the first reinforcing member 30 is the same as that of the vehicle body frame 1, the same components as those of the body frame 1 are denoted by the same reference numerals. Is omitted.

  As shown in FIG. 10, also in the vehicle body frame 81 to which the vehicle frame structure according to the second embodiment of the present invention is applied, the side surface portions 12 of the first plate-like members 10 on both sides are provided in the same manner as the vehicle body frame 1. The first reinforcing member 30 that connects the boundary portions 12b between the curved portion 1c and the straight portion 12a is provided. In the vehicle body frame 81, the first plate member 10 and the bottom surface portion 11 are further connected to the first reinforcing member 30. A second reinforcing member 90 is provided for connecting the reinforcing member 30 to the second reinforcing member 90.

  The second reinforcing member 90 is formed of a metal plate-like material such as a steel plate, extends along the longitudinal direction of the body frame 1, and extends in the orthogonal cross-section direction that is perpendicular to the longitudinal direction of the body frame 81. The first plate member 10 extends in a substantially vertical direction with respect to the bottom surface portion 11 of the first plate member 10, and connects the bottom surface portion 11 of the first plate member 10 and the first reinforcing member 30. Are joined to the bottom surface portion 11 and the first reinforcing member 30 by welding or the like.

  In the vehicle body frame 81 shown in FIG. 10, specifically, a second portion that connects the central portion 11 b between the side surface portions 12 on both sides of the bottom surface portion 11 of the first plate-like member 10 to the first reinforcing member 30. A reinforcing member 91 and a second reinforcing member 92 that couples the boundary portion 11c between the curved portion 1c and the straight portion 11a on both sides of the bottom surface portion 11 of the first plate-like member 10 to the first reinforcing member 30 respectively. The second reinforcing member is provided so as to connect the side portions 12 on both sides and the center side between the side portions 12 on both sides of the bottom surface portion 11 of the first plate-like member 10 to the first reinforcing member 30. 91 and 92 are provided.

  As described above, the vehicle body frame 81 according to the second embodiment of the present invention includes the first surface portion 11 on which a force in the compression direction acts when a load is applied from the outside, and the second surface portion 21 on which a force in the tension direction acts. In the direction orthogonal to the longitudinal direction of the vehicle body frame 81, the first connecting portion 30 is connected to the boundary portion 12b between the curved portion 1c and the straight portion 12a in the third surface portions 12 and 22 on both sides. The first connecting portion 90 extends in a substantially vertical direction with respect to the first surface portion 11 and connects the first surface portion 11 and the first connecting portion 30.

  As a result, when a load is applied from the outside to the body frame 81 as well, the third surface portions 12 and 22 on both sides of the first surface portion 11 are removed as the first surface portion 11 is deformed inwardly of the body frame 81. Since it can be effectively suppressed by the first connecting portion 30 that connects the boundary portions 12b between the curved portion 1c and the linear portion 12a in the third surface portions 11 and 12 on both sides, the first connecting portion 30 that swells and deforms in the lateral direction can be effectively suppressed. The bending strength of the frame can be improved while suppressing an increase in weight.

  Further, in the vehicle body frame 81, the first connecting portion 30 is deformed inward of the vehicle body frame 81 via the second connecting portion 90 in accordance with the deformation of the first surface portion 11 inward of the vehicle body frame 81. Therefore, the first connecting portion 30 can act so as to pull the third surface portions 11 and 12 on both sides inward of the vehicle body frame 81, and the above-described effect can be more effectively achieved.

  In the present embodiment, when the second reinforcing member 90 is added in addition to the first reinforcing member 30 inside the vehicle body frame 81, the position of the second reinforcing member 90 and the weight efficiency of the bending strength, specifically The relationship between the ratio of the maximum bending load per unit weight of each body frame to the maximum bending load per unit weight for the body frame 101 (comparative example) shown in FIG. 12 was examined.

  FIG. 11 is a diagram showing an analysis result of bending strength with respect to the vehicle body frame in which the curvature radius of the upper corner portion is 15 mm. The curvature radius of the curved portion 1c of the corner portion 1a is 15 mm and the first reinforcing member 30 is shown. The result of analyzing the vehicle body frame 81 whose position is 10 mm connecting the boundary portions 12b between the curved portion 1c and the straight portion 12a is shown. As shown in FIG. 11, the maximum bending load was analyzed for each vehicle body frame to which the second reinforcing member 90 was attached, and the ratio of the maximum bending load per unit weight with respect to the comparative example was evaluated.

  Specifically, the vehicle body having a second reinforcing member provided so as to connect the boundary portion 11 c and the central portion 11 b on both sides of the bottom surface portion 11 of the first plate-like member 10 to the first reinforcing member 30. The frame is the sample 2A, and the vehicle body frame having the second reinforcing member provided so as to connect only the central portion 11b of the bottom surface portion 11 of the first plate-like member 10 to the first reinforcing member 30 is the sample 2B. A vehicle body frame having a second reinforcing member provided so as to connect the boundary portions 11c on both sides of the bottom surface portion 11 of the first plate-like member 10 to the first reinforcing member 30, respectively. The plate-like member 10 includes a second reinforcing member provided so as to connect the boundary portion 11c and the central portion 11b on both sides of the bottom surface portion 11 to the first reinforcing member 30, and the first reinforcing member 30. A vehicle body frame further including a second reinforcing member provided so as to connect the central portion between the boundary portion 11c and the central portion 11b on both sides of the bottom surface portion 11 of the shaped member 10 to the first reinforcing member 30. Evaluated as sample 2D.

  The vehicle body frame shown in FIG. 11 is evaluated using the same thing as the vehicle body frame 101 shown in FIG. 12 except that the first reinforcing member 30 and the second reinforcing member 90 are added. The reinforcing member 90 was evaluated as a 980 MPa class high-tensile steel plate having a plate thickness of 1.0 mm, similar to the first reinforcing member 30.

  As shown in FIG. 11, the weight efficiency of the bending strength of the vehicle body frame to which the second reinforcing member 90 that connects the bottom surface portion 11 of the first plate-like member 10 and the first reinforcing member 30 is attached is a sample. 2A, Sample 2B, Sample 2C, and Sample 2D are higher than those of the comparative example, and more than the case of the vehicle body frame 1 shown in FIG. 2 in which the second reinforcing member 90 is not provided. It can be seen that the weight efficiency of the bending strength is further improved.

  Thus, between the 1st surface part 11 to which the force of a compression direction acts when the load acts from the outside, the 2nd surface part 21 to which the force of a tension direction acts, between the 1st surface part 11 and the 2nd surface part 21 It has the 3rd surface parts 12 and 22 of the both sides which are located, and the corner | angular part 1a of the both sides formed between the 1st surface part 11 and the 3rd surface parts 12 and 22 of both sides is formed by the curved part 1c, and is 1st. In the vehicle body frame in which the portion adjacent to the curved portion 1c in the three surface portions 12 and 22 is formed by the straight portion 12a, the boundary portion 12b between the curved portion 1c and the straight portion 12a in the third surface portions 12 and 22 on both sides is connected. While providing the 1st connection part 30, it is extended in the substantially perpendicular direction with respect to the 1st surface part 11, and the increase in weight is provided by providing the 2nd connection part 90 which connects the 1st surface part 11 and the 1st connection part 30. While suppressing the bending strength of the frame It is possible to improve on.

  In this embodiment, the vehicle body frame is formed in a closed cross-section by overlapping the flange portions of two metal plate-like members formed in a cross-section hat, but the plate formed in a cross-section hat It is also possible to form the vehicle body frame in a closed cross-section by superimposing the plate-like member on the plate-like member formed in a substantially flat plate shape.

  In the present embodiment, the first and second plate members made of metal such as a steel plate are welded to form a body frame in a closed cross-sectional shape, and the plate material made of metal such as a steel plate. The reinforcing members 30 and 90 are attached to the vehicle body frame to form the first connection portion and the second connection portion. However, when the vehicle body frame is formed using aluminum, the first connection portion and the second connection portion are formed. It is also possible to form the part by extrusion molding integrally with the vehicle body frame having a closed cross-sectional shape. In addition, the reinforcing member can be made of resin.

  As described above, the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes can be made without departing from the gist of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can provide a vehicle frame structure that can improve the bending strength of the frame while suppressing an increase in weight, and is widely used for a vehicle body frame that forms part of a vehicle body such as a pillar or a side sill. There is a possibility that.

1, 41, 51, 61, 71, 81 Body frame 1a, 1b Corner portion 10 First plate member 11 Bottom surface portion (first surface portion) of first plate member
12 Side surface portion (third surface portion) of first plate-like member
20 Second plate member 21 Bottom surface portion (second surface portion) of second plate member
22 Side surface portion (third surface portion) of second plate-shaped member
30, 60, 70 First reinforcing member 90, 91, 92 Second reinforcing member

Claims (7)

A vehicle frame structure comprising a part of a vehicle body and having a frame formed in a closed cross-sectional shape,
The frame includes a first surface portion on which a force in the compression direction acts when a load is applied from the outside, a second surface portion on which the force in the tensile direction acts on the first surface portion, and a first surface portion of the frame. A third surface portion on both sides forming a corner portion between the first surface portion and the second surface portion, located between the second surface portion and the second surface portion;
The corner portions on both sides formed between the first surface portion and the third surface portions on both sides are each formed by a curved portion extending in a curved shape in the cross section of the frame, and the curve in the third surface portion. A portion adjacent to the portion is formed by a straight portion extending linearly in the cross section of the frame;
The frame has a first connecting part that connects boundary portions between the curved part and the straight part in the third surface part on both sides.
A vehicle frame structure characterized by that. The first surface portion is formed of a linear portion in which a portion between the curved portions on both sides extends linearly,
The first connecting portion is provided substantially parallel to the straight portion of the first surface portion.
The vehicle frame structure according to claim 1. The frame includes a second connecting portion that connects the first surface portion and the first connecting portion;
The second connecting portion extends in a direction substantially perpendicular to the first surface portion in a direction orthogonal to the longitudinal direction of the frame.
The vehicle frame structure according to claim 1, wherein the vehicle frame structure is a vehicle frame structure. The frame includes the second connecting part provided to connect the third surface part on both sides of the first surface part and the central side between the third surface parts on both sides to the first connecting part. Yes,
The vehicle frame structure according to claim 3. The frame includes the second connecting portion provided so as to connect the third surface portions on both sides of the first surface portion with the first connecting portion, respectively.
The vehicle frame structure according to claim 3. The frame includes the second connecting portion provided so as to connect a center side between the third surface portions on both sides of the first surface portion with the first connecting portion.
The vehicle frame structure according to claim 3. The frame is a center pillar that is positioned between front and rear door openings provided on the side surface of the vehicle body and extends in the vertical direction of the vehicle body.
The vehicle frame structure according to claim 1, wherein the vehicle frame structure is a vehicle frame structure.

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