Front body structure

Abstract

To provide a vehicle front structure that allows for miniaturization of reinforcing members (moment cancellers) and greater freedom in the placement of components located above the side frame. [Solution] The front structure of the vehicle body (10) includes a reinforcing member (80) that reinforces the side frame (11) in order to suppress upward bending of the side frame (11). The first end (82) of the reinforcing member (80) on the load input side is joined to the boundary (58) between the straight lower wall (56) and the inclined lower wall (57). The second end (83) of the reinforcing member (80) on the opposite side from the load input side is joined to the cross member (12). The reinforcing member (80) extends diagonally upward from the first end (82) to the second end (83).

Description

【Technical Field】 【0001】 The present invention relates to a front body structure provided with a reinforcing member. 【Background Art】 【0002】 The front structure of the body of a four-wheel vehicle is disclosed in Patent Document 1. This body structure includes a pair of side frames (front side members) extending in the front-rear direction. Each side frame is bent as a whole and has a straight portion extending linearly in the front-rear direction and an inclined portion extending rearward and downward from the straight portion. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent No. 7679152 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 When a vehicle frontal collision occurs and there is a load input from the front of the vehicle, a moment that bends the front side frame upward occurs. To cancel this moment, a reinforcing member (moment canceller) is provided. By canceling the moment that tries to bend the front side frame upward with the reinforcing member and promoting the compressive deformation of the front side frame (compressive deformation allowable portion), the impact absorption performance of the vehicle can be improved. 【0005】 Since the front part of the reinforcing member is fixed to the straight portion of the side frame from above, and the rear part is fixed to the upper cowl side panel because it is supported by the front pillar, and it is a large part that widely occupies the space above the side frame, it is difficult to attach body structure parts, drive parts, etc., and there is room for improvement. 【0006】 The present invention aims to provide a vehicle front structure that miniaturizes the reinforcing member (moment canceller) and offers greater flexibility in the arrangement of components located above the side frame. [Means for solving the problem] 【0007】 In this disclosure, A side frame comprising a lower wall portion having a straight lower wall portion extending in the vehicle's longitudinal direction and an inclined lower wall portion extending diagonally downward from the straight lower wall portion, A cross member extending in the width direction of the vehicle, joined to the front pillar and also joined to the side frame, Includes a reinforcing member that reinforces the side frame in order to suppress upward bending of the side frame, The first end of the reinforcing member on the load input side is joined to the boundary between the straight lower wall portion and the inclined lower wall portion. The second end of the reinforcing member opposite to the load input side is joined to the cross member. The reinforcing member extends diagonally upward from the first end to the second end, providing a front body structure for the vehicle. [Effects of the Invention] 【0008】 This invention provides a vehicle front structure that allows for miniaturization of reinforcing members and offers greater flexibility in the arrangement of components located above the side frame. [Brief explanation of the drawing] 【0009】 [Figure 1] This is a perspective view of the front body structure of the vehicle according to the embodiment, taken from a diagonal front view. [Figure 2] Figure 1 is a perspective view of the front structure of the vehicle body, taken from a diagonal rearward angle. [Figure 3] Figure 3A: This diagram illustrates the end of the cross member of the front body structure shown in Figure 1. Figure 3B: This is a cross-sectional view taken along line 3B-3B in Figure 3A. [Figure 4] This is a cross-sectional view taken along line 4-4 in Figure 1. [Figure 5] This is a cross-sectional view taken along line 5-5 in Figure 1. [Figure 6] It is a sectional view taken along line 6-6 of FIG. 5. [Figure 7] It is a view of the structure according to the sectional view taken along line 6-6 of FIG. 5 as seen obliquely from the rear. [Figure 8] It is a view of the structure with one side of the side frame removed as seen obliquely from the front. [Figure 9] It is a sectional view taken along line 9-9 of FIG. 1. [Figure 10] It is an enlarged view of the part surrounded by line 10 in FIG. 1. [Figure 11] It is a view in the direction indicated by arrow 11 in FIG. 10. [Figure 12] It is a view in the direction indicated by arrow 12 in FIG. 10. [Figure 13] It is a schematic view of the cross-section of the side frame. [Figure 14] It is an exploded perspective view of the front body structure where the ridge lines are continuous. 【Mode for Carrying Out the Invention】 【0010】 <Example> Examples will be described based on the attached drawings. The examples described here are not intended to particularly limit the present invention. Also, members and parts having the same function are given the same reference numerals, and overlapping explanations are omitted or simplified as appropriate. 【0011】 In the figures, Fr indicates front, Rr indicates rear, Le indicates left, Ri indicates right, Up indicates up, and Dn indicates down. The vehicle length direction is the front-rear direction (the front is the load input side, and the rear is the opposite side). The vehicle width direction is the left-right direction. The direction approaching the center in the vehicle width direction is in, and the direction away from the center is out. The vehicle height direction is the up-down direction. 【0012】 Refer to FIGS. 1 and 2. The front structure of the body of a four-wheeled vehicle (body front structure 10) is shown. The body front structure 10 includes a pair of side frames 11 (front side frames) that extend in the vehicle length direction and are symmetric about the vehicle width direction, and a cross member 12 that extends in the vehicle width direction and is joined to the rear end of each of the side frames 11. Here, "joined" means welding, bolt fastening, riveting, adhesion, etc. 【0013】 (Cross member) Refer to FIGS. 1 and 2. The cross member 12 joins with a dash panel (not shown) that separates the space where a drive source such as an engine is arranged and the passenger compartment to form a closed cross section. Both ends of the cross member 12 are joined to the left and right front pillars 13. 【0014】 The cross member 12 includes an upper cross member 20 (dash cross member), a lower cross member 30 (dash lower cross member) located below the upper cross member 20, and left and right torque boxes 34 that sandwich the lower cross member 30 and the side frames 11 and connect the side frames 11 and a side sill (not shown). 【0015】 (Upper cross member) The upper cross member 20 has an intermediate portion 21 to which the rear ends of the pair of side frames 11 are joined at both side ends 21a, and two protruding portions 27 that protrude obliquely outward and rearward from both side ends 21a of the intermediate portion 21. In other words, the upper cross member 20 is bent rearward with the ends of the intermediate portion 21 as a base point. Therefore, the upper cross member 20 is easy to join to the front pillar 13. 【0016】 (Protruding portion) Refer to FIGS. 3A and 3B. The protruding portion 27 has a roughly hat-shaped cross section that opens to the rear. The height H3 of the hat cross section decreases as it extends outward. A convex transverse bead 28 extending in the vehicle width direction is formed on the protruding portion 27. The height H4 and width W of the transverse bead 28 increase as it extends outward. As the height H3 of the hat cross section decreases as it extends outward, but the height H4 and width W of the transverse bead 28 increase, bending rigidity can be maintained and the length of the cross section can be kept constant, thus suppressing molding wrinkles. 【0017】 The protruding portion 27 has a pillar mounting portion 29 that can be attached to the front surface 13a and the ridge line 13b (corner) of the front surface 13a of the front pillar 13. Therefore, the support rigidity of the cross member 12 is high. 【0018】 The tip 28a of the lateral bead 28 is located at the pillar mounting portion 29 (the lateral bead 28 is formed up to the pillar mounting portion 29). Therefore, the load applied to the protruding portion 27 can be reliably transmitted to the front pillar 13. 【0019】 Refer to Figures 1 and 4. The intermediate portion 21 of the upper cross member 20 has a front portion 22 extending in the vertical direction, an upper portion 23 extending upward from the upper end of the front portion 22, an upper flange portion 24 extending upward from the rear end of the upper portion 23, and a lower portion 25 extending downward from the lower end of the front portion 22. A concave central bead 26 extending in the vehicle width direction is formed in the front portion. 【0020】 The cross-section of the intermediate portion 21 of the upper cross member 20 is uniform in the vehicle width direction (the cross-sectional shape does not change regardless of the position in the vehicle width direction). Therefore, the upper cross member 20 can receive the load transmitted from the side frame 11 as a whole. 【0021】 (bending angle) Within the intermediate section 21, comparing the first bending angle R1 between the lower section 25 and the front section 22, the second bending angle R2 between the front section 22 and the upper section 23, and the third bending angle R3 of the central bead 26, the relationship is R1 > R2 > R3. By using high-strength steel plate as the material for the upper cross member 20, it becomes possible to form it without forming defects such as forming wrinkles, and the bending rigidity is improved, so the cross section of the upper cross member 20 can be reduced. Therefore, it is not necessary to bulge the inclined cross member 40 towards the passenger compartment, and the passenger compartment can be made wider. 【0022】 (Inclined cross member) The inclined cross member 40 includes a dash lower panel inclined section 42 that extends inclined to the rear, connected to the left and right sides of the lower cross member 30 via side frames to form a triangular closed section, and a bottom member 33 that extends forward from the lower end of the dash lower panel inclined section 42. The bottom member 33 and the dash lower panel inclined section 42 together with the rear side section 32 of the side frame form a triangular closed section. The torque box 34 has a frame structure that allows for a wider passenger compartment because the left and right sides of the lower cross member 30 are connected to the triangular closed section via side frames 11. 【0023】 Refer to Figure 2. Of the inclined portion 42 of the lower dash panel of the torque box 34, the portion located behind the protruding portion 27 of the upper cross member 20 is defined as the vertical portion 43 of the lower dash panel. The vertical portion 43 of the lower dash panel has a bulge 43a formed to bulge outwards towards the rear. This suppresses bending deformation of the upper cross member 20. The bulge 43a has an inclined bead 43b that is tilted in the vertical direction. 【0024】 The section located behind the upper cross member 20 and behind the intermediate section 21 is defined as the vertical section 44 of the lower dash panel. The vertical section 44 of the lower dash panel has a bulge 44a formed to bulge outwards towards the rear. A vertical bead 44b extending in the vertical direction is formed thereon. The vertical bead 44b and the inclined bead 43b can suppress vibrations of the rear cross member 40. 【0025】 (Lower cross member) Refer to Figures 1 and 4. The lower cross member 30 located below the intermediate section 21, the horizontal bottom member 33 with its thickness in the vertical direction, and the inclined section 42 of the dash lower panel form a triangular closed cross section. The side frame 11 is located between the lower cross member 30 and the rear side section 32 of the side frame on the bottom member 33. 【0026】 (Cross member joining) The upper end 41a of the vertical portion 41 of the lower dash panel and the upper flange portion 24 of the upper cross member 20 are joined. The upper end 42a of the inclined portion 42 of the dash cross member and the upper end 30a of the lower cross member 30 are joined, sandwiching the lower end 25a of the lower portion 25 of the intermediate portion 21. The lower end 30b of the lower cross member 30 and the front end 33a of the bottom member 33 are joined (a single L-shaped cross section may also be used). The lower end 42b of the inclined portion 42 of the dash cross member and the rear end 33b of the bottom member 33 are joined. 【0027】 (Rear side of the side frame) Refer to Figures 3A and 3B. The rear side portion 32 of the side frame has a roughly hat-shaped cross section and is joined to the protruding portion 27 of the upper cross member 20, the bottom member 33, and the second frame 60, which will be described later. The second frame 60 of the side frame 11 has a first ridge line E1 that extends in the vehicle length direction. The rear side portion 32 of the side frame has a second ridge line E2 that extends in the vehicle width direction and rearward. The first ridge line E1 and the second ridge line E2 are connected. Therefore, the load applied to the side frame 11 can be transmitted to the front pillar 13 via the rear side portion 32 of the side frame. Note that the first ridge line E1 and the second ridge line E2 are examples, and the second frame and the rear side portion 32 of the side frame may be integrally molded, and their cross-sectional shapes can be changed as appropriate, as long as the ridge lines formed according to the shape are connected to each other. 【0028】 (Side frame) Refer to Figure 5. The side frame 11 is constructed by joining together a first frame 50 located on the inside and a second frame 60 located on the outside. The first frame 50 and the second frame 60 form a closed cross-section. The side frame 11 may be divided vertically, or it may be a single member. The longitudinal direction of the cross-section of the side frame 11 is the vehicle height direction. 【0029】 The first frame 50 has a roughly hat-shaped cross-section and includes a first lower wall portion 51, an inner wall portion 52 extending upward from the inner edge of the first lower wall portion 51, a first upper wall portion 53 extending inward from the upper end of the inner wall portion 52, a first upper flange portion 54 extending upward from the outer end of the first upper wall portion 53, and a first lower flange portion 55 extending downward from the inner end of the first lower wall portion 51. 【0030】 The second frame 60 is roughly plate-shaped and has an outer wall portion 61 facing the inner wall portion 52, a second upper flange portion 62 joined to the first upper flange portion 54, and a second lower flange portion 63 joined to the first lower flange portion 55. 【0031】 Refer to Figures 5 and 6. The first lower wall portion 51 of the first frame 50 has a straight lower wall portion 56 extending in the front-rear direction and an inclined lower wall portion 57 extending diagonally downward from the straight lower wall portion 56. The rear end portion 52a of the inner wall portion 52 has an extended wall portion 59 extending diagonally downward from its lower part. The portion extending from the rear end portion 56a of the straight lower wall portion 56 to the front end portion 57a ​​of the inclined lower wall portion 57 is defined as the boundary 58 between the straight lower wall portion 56 and the inclined lower wall portion 57. The straight lower wall portion 56 is a horizontal straight portion, and the front end portion 57a ​​is the front end portion of the first joining member 70 which is positioned in the inclined lower wall portion 57. 【0032】 (First joining member) Refer to Figures 6 and 7. The first connecting member 70 is joined to both the bottom member 33 of the side frame 11 and the cross member 12. The shape of the first connecting member 70 can be changed as appropriate, but one example is described below. 【0033】 The first joining member 70 has a first inclined portion 71 joined to the inclined lower wall portion 57 of the first frame 50, a first bottom portion 72 joined to the bottom member 33 of the lower cross member 30, a first inner wall portion 73 extending upward from the inner edges of the first inclined portion 71 and the first bottom portion 72 and joined to the inner wall portion 52 and the extended wall portion 59 of the first frame 50, and a first mounting portion 74 extending inward from the upper edge of the first inner wall portion 73 and joined to the lower part 42 of the rear cross member 40. The portion where the bottom member 33 and the first bottom portion 72 are joined is called the lower joining portion J3. The first joining member 70 can also be said to penetrate the lower cross member 30. 【0034】 (Reinforcement member) Refer to Figures 6 to 9. The internal space S formed by the first frame 50 and the second frame 60 is provided with a reinforcing member 80 that reinforces the side frame 11. The reinforcing member 80 has a crank-shaped cross-section overall and includes a main body portion 81 that extends linearly diagonally upward from the first end portion 82 on the load input side to the second end portion 83 on the opposite side, an upper bent portion 84 that extends upward from the inner edge of the main body portion 81, and a lower bent portion 86 that extends upward from the outer edge of the intermediate portion 21. Note that the reinforcing member 80 only needs to have at least the main body portion 81. 【0035】 (Joining of reinforcing members) The first end portion 82 of the main body portion 81 is joined to the rear end portion 56a of the straight lower wall portion 56 of the first frame 50 (see Figure 6J1). The second end portion 83 is joined to the upper portion 23 of the intermediate portion 21 of the upper cross member 20. The portion where the second end portion 83 and the upper portion 23 are joined is called the upper joint portion J2. The second end portion 83 may also be joined to the front portion 22 of the intermediate portion 21. Furthermore, the rear flange portion 53a of the first frame 50 is joined to the second end portion 83. 【0036】 Refer to Figures 8 and 9. The upper bent portion 84 is belt-shaped, and its front end portion 85 is joined to the inner wall portion 52 of the first frame 50 (see J4). The portion of the upper bent portion 84 that is joined to the inner wall portion 52 can be changed as appropriate. 【0037】 As shown in Figure 8, the lower bent portion 86 is roughly triangular in side view, and the lower end portion 87, which corresponds to one side of the triangle, is joined to the first lower flange portion 55 of the first frame 50 (see J5). 【0038】 (Tensile strength) The steel plates of each component constituting the front body structure 10 can be selected as appropriate. For example, the tensile strength of the upper cross member 20 (2000 MPa) is greater than the tensile strength of the side frames 11 (first frame 50 and second frame 60) and the reinforcing members 80 (980 MPa). 【0039】 (Second joining member) Refer to Figures 6 to 8. A second connecting member 90 is joined to both the side frame 11 and the bottom member 33 of the cross member 12. The second connecting member 90 is further joined to the reinforcing member 80 (J6). The shape of the second connecting member 90 can be changed as appropriate, but one example is described below. 【0040】 The second joining member 90 includes a second inclined portion 91 joined to the first inclined portion 71, a second bottom portion 92 joined to the first bottom portion 72, a second outer wall portion 93 extending upward from the outer edges of the second inclined portion 91 and the second bottom portion 92 and joined to the inner surface 86a of the lower bent portion 86 of the reinforcing member 80, and an outer mounting portion 94 extending outward from the upper end of the second outer wall portion 93 and joined from the lower end 23a of the front portion 22 of the intermediate portion 21 of the upper cross member 20 to the rear lower portion of the rear cross member 40. 【0041】 The second inclined portion 91 and the second bottom portion 92 are joined to the first frame 50 via the first joining member 70, but they may also be joined directly to the first frame 50 without using the first joining member 70. 【0042】 During the manufacturing of the front body structure 10, the first connecting member 70, the second connecting member 90, and the reinforcing member 80 are assembled and joined to the first frame 50 in that order, and finally the first frame 50 and the second frame 60 are joined to form the side frame 11. 【0043】 Refer to Figure 5. The first joining member 70 and the second joining member 90 are U-shaped when viewed along the vehicle width direction. 【0044】 The first joining member 70 and the second joining member 90 are auxiliary members (side frame rear end) provided between the side frame 11 and the cross member 12, and can also be described as members that extend the side frame 11 toward the cross member 12. Depending on the shape of the side frame 11 and the cross member 12, it is also possible to provide either the first joining member 70 or the second joining member 90, or to provide neither. 【0045】 (Shape change section) Refer to Figures 1 and 10. The first upper wall portion 53 of the side frame 11 has a shape-changing portion 101 that changes shape in the thickness direction of the first upper wall portion 53 in order to control the deformation behavior when a compressive load in the vehicle length direction is applied. Within the first upper wall portion 53, the area in front of the shape-changing portion 101 is designated as the first flat portion 111, and the area behind the shape-changing portion 101 is designated as the second flat portion 112. 【0046】 The shape-changing portion 101 is composed of a first protrusion 120 that protrudes to the front side in the thickness direction of the plate, and a second protrusion 130 that protrudes to the front side in the thickness direction of the plate, which are arranged alternately adjacent to each other in the vehicle length direction. 【0047】 (sloping ridgeline) Refer to Figures 10 and 13. For the sake of explanation, Figure 13 schematically shows a cross-section of the side frame 11. 【0048】 The tip of the first projection 120 is a first inclined ridge 121, where the amount of protrusion decreases as it moves from the inner end 122 to the outer end 123 (inclination angle θ1). The tip of the second projection 130 is a second inclined ridge 131, where the amount of protrusion increases as it moves from the inner end 132 to the outer end 133 (inclination angle θ2). Within the shape-changing section 101, the first inclined ridge 121 and the second inclined ridge 131 can also be described as convex portions. 【0049】 Viewed along the vehicle width direction (see Figure 13), the angle at which the first inclined ridge 121 and the second inclined ridge 131 intersect is defined as the intersection angle θ3. The inclination angles θ1 and θ2 can be appropriately changed according to the required load peak and collision stroke. For example, if the inclination angles θ1 and θ2 are increased, the intersection angle θ3 will decrease, the load peak will decrease, and the collision stroke will increase. 【0050】 Refer to Figure 11. The distance D between the first protrusion 120 and the second protrusion 130 (the distance between the first inclined ridge 121 and the second inclined ridge 131) can be changed as appropriate. If the distance D is widened, the area between the first protrusion 120 and the second protrusion 130 will become closer to flat, but it will not become completely flat (there are no flat areas within the shape-changing section 101). The first inclined ridge 121 and the second inclined ridge 131 extend along the vehicle width direction (left-right direction), but they may also be inclined. 【0051】 (Connecting ridge) Refer to Figures 10 and 11. The outer end 123 (one end with a small protrusion) of the first inclined ridge 121 and the inner end 132 (the other end with a small protrusion) of the second inclined ridge 131 are connected by a connecting ridge 140. The connecting ridge 140 is a straight line and also serves as the boundary line between the first protrusion 120 and the second protrusion 130. Within the shape-changing section 101, the connecting ridge 140 can also be described as a recess. 【0052】 Refer to Figure 11. In plan view, the first projection 120 is triangular in shape. The first projection 120 comprises a first triangular plane 120a whose sides include the connecting ridge 140 and the first inclined ridge 121, and a second triangular plane 120b adjacent to the first triangular plane 120a, whose sides include the first inclined ridge 121 and the connecting ridge 140. 【0053】 In plan view, the second projection 130 is triangular in shape. The second projection 130 has a first triangular plane 130a that includes the connecting ridge 140 and the second inclined ridge 131 as sides, and a second triangular plane 130b adjacent to the first triangular plane 130a that has the first inclined ridge and the connecting ridge 140. 【0054】 In other words, the shape-changing section 101 is composed of a first projection 120 having two triangular planes 120a and 120b, and a second projection 130 having two triangular planes 130a and 130b, which are arranged alternately adjacent to each other in the vehicle length direction via a connecting ridge line 140 (sharing the connecting ridge line 140). In a plan view, the triangular first projection 120 and the triangular second projection 130 have the same shape, but their orientations are opposite. 【0055】 (Edges of the shape change section) Refer to Figure 12. The first flat section 111 is located at the vehicle width end of the first upper wall section 53 and has straight ridges 111a and 111b extending in the vehicle length direction. The second flat section 112 is located at the vehicle width end and has straight ridges 112a and 112b extending in the vehicle length direction. Each ridge is formed by the corners of the cross-section of the side frame 11 being connected in the vehicle length direction. 【0056】 In a side view, the shape-changing section 101 has wavy ridges 101a and 101b at its ends in the vehicle width direction. The wavy ridges 101a and 101b are formed by the connection of the inner and outer edges of the first protrusion 120 and the second protrusion 130 in the vehicle width direction, respectively. The wavy ridges 101a and 101b are wavy at positions corresponding to the linear virtual ridges 53c and 53d that form the corners of the side frame 11 in a schematic polygonal cross-section (see Figure 12) (virtual ridge 53c is located on the same line as ridges 111a and 112a, and virtual ridge 53d is located on the same line as ridges 111b and 112b) (they are wavy at positions corresponding to the shape-changing section 100 of the entire ridge of the first upper wall section 53). In this embodiment, the amplitude (protrusion amount) and pitch (interval D) are constant, resulting in a wave-like pattern. However, for example, a wave-like pattern that attenuates (where the amplitude is large on the load input side and the pitch (interval D) gradually narrows toward the opposite side of the load input) may also be used. This can be freely set according to the required collision mode. 【0057】 As described above, the shape-changing portion 101 is formed by the adjacent first protrusion 120 and second protrusion 130, but "protrusion" does not necessarily mean protruding above the first flat portion 111 or the second flat portion 112; it is sufficient for the shape-changing portion 101 itself to have an uneven surface. In this embodiment, the second inclined ridge line 131 of the second protrusion 130 is located on the same plane as the first flat portion 111 and the second flat portion 112. 【0058】 Refer to Figures 10 and 13. The shape-changing portion 101 is also formed in areas other than the first upper wall portion 53. An example will be explained. 【0059】 The inner wall portion 52 of the first frame 50 has a first groove 150 extending in the vehicle length direction. The first groove 150 has a first lower horizontal portion 151 extending in the vehicle width direction, a first vertical portion 152 extending upward from the inner edge of the first lower horizontal portion 151, and a first upper horizontal portion 153 extending inward from the upper edge of the first vertical portion 152. A shape-changing portion 102 is formed in the first lower horizontal portion 151. A shape-changing portion 103 is formed in the first upper horizontal portion 153. 【0060】 A shape-changing portion 104 is formed on the second upper wall portion 64 of the second frame 60. The outer wall portion 61 of the second frame 60 has a second groove 160 extending in the vehicle length direction. The second groove 160 has a second lower horizontal portion 161 extending in the vehicle width direction, a second vertical portion 162 extending upward from the inner edge of the second lower horizontal portion 161, and a second upper horizontal portion 163 extending outward from the upper edge of the second vertical portion 162. A shape-changing portion 105 is formed on the second lower horizontal portion 161. A shape-changing portion 106 is formed on the second upper horizontal portion 163. 【0061】 When viewed from the vehicle's longitudinal direction, the shape-changing sections 101 to 106 are located in the same position. Note that the position and presence or absence of each of the shape-changing sections 101 to 106 can be changed as appropriate. 【0062】 In this embodiment, the shape-changing sections 101-106 are formed only in the parts of the side frame 11 where the plate thickness direction is in the vehicle height direction (such as the first upper wall section 53 and the first upper horizontal section 153), and not in the parts where the plate thickness direction is in the vehicle width direction (such as the first vertical section 152). The cross-section of the side frame 11 has the vehicle height direction as its longitudinal direction, making it difficult to deform in the vehicle height direction. By forming the shape-changing sections only in the parts where the plate thickness direction is in the vehicle height direction, deformation in the vehicle height direction is promoted, enabling stable compression of the side frame 11 as a whole in the vehicle length direction. 【0063】 Refer to Figure 14. The side frame 11A consists of a first frame 50A and a second frame 60A that are joined to each other in the vehicle width direction. The first frame 50A has shape-changing sections 301 to 303. 【0064】 The second frame 60A has a side body portion 210 extending in the vehicle length direction, and a rear side portion 220 extending outward from the rear end of the side body portion 210 and connectable to a cross member (not shown). The side body portion 210 has shape-changing portions 304 to 306. 【0065】 The outer wall portion 213 (side wall portion) of the side main body portion 210 has four first ridges 211 formed thereon. The rear side portion 220 has four second ridges 221 formed thereon. The four first ridges 211 and the four second ridges 221 are connected. The number of ridges can be changed as appropriate. It is sufficient that at least one ridge is connected. 【0066】 (Effect of the example) Refer to Figure 6. Firstly, the front structure of the vehicle body 10 is A side frame 11 comprises a lower wall portion 51 having a straight lower wall portion 56 extending in the vehicle length direction and an inclined lower wall portion 57 extending diagonally downward from the straight lower wall portion 56, A cross member 12 extends in the width direction of the vehicle and is joined to the front pillar 13 and also to the side frame 11, To suppress upward bending of the side frame 11, a reinforcing member 80 is included which reinforces the side frame 11. The first end 82 of the reinforcing member 80 on the load input side is joined to the boundary 58 between the straight lower wall portion 56 and the inclined lower wall portion 57 (any range from the rear end portion 56a to the front end portion 57a), The second end 83 of the reinforcing member 80, opposite to the load input side, is joined to the cross member 12. The reinforcing member 80 extends diagonally upward from the first end 82 to the second end 83. 【0067】 The reinforcing member 80 acts as a moment canceller. When a vehicle is struck head-on and a load is applied from the front of the vehicle, the reinforcing member 80 eliminates the moment that would cause the side frame 11 to bend upward, thereby promoting the compressive deformation of the side frame 11 and improving the impact absorption performance of the vehicle. 【0068】 In detail, the reinforcing member 80 extends diagonally upward from a first end 82 joined to the lower wall portion 51 of the side frame 11 to a second end 83 joined to the cross member 12, and is small in size. Therefore, by miniaturizing the reinforcing member 80 and arranging it inside the side frame 11, it is possible to provide a vehicle front structure 10 that offers a high degree of freedom in the arrangement of components provided above it. 【0069】 Secondly, in the first front body structure 10, It includes a first joining member 70 that is joined to both the side frame 11 and the bottom member 33 of the cross member 12, Using the joint J1 between the lower wall portion 51 of the side frame 11 and the first end portion 82 of the reinforcing member 80 as a reference, The height H1 from the joint J1 to the upper joint J2 between the second end 83 of the reinforcing member 80 and the cross member 12, The height H2 from the joint J1 to the lower joint J3 between the first joint member 70 and the bottom member 33 is set to be approximately equal. 【0070】 Since the length (height) of the arm of the moment that attempts to bend the side frame 11 is approximately equal to the length (height) of the arm of the moment that attempts to suppress the bending of the side frame 11, the moment that attempts to bend the side frame 11 can be canceled out. 【0071】 Refer to Figure 8. Thirdly, in the first front body structure 10, The reinforcing member 80 has a crank-shaped cross-section and comprises a main body portion 81 having a first end portion 82 and a second end portion 83 at both ends, an upper bent portion 84 extending upward from one edge of the main body portion 81, and a lower bent portion 86 extending downward from the opposite edge of the main body portion 81. By making the reinforcing member 80 have a crank-shaped cross-section, the rigidity of the reinforcing member 80 itself is increased. 【0072】 Refer to Figures 8 and 9. Fourth, in the third front body structure 10, The upper bent portion 84 and the lower bent portion 86 of the reinforcing member 80 are joined to the side frame 11 (see J4, J5). The crank-shaped reinforcing member 80 is joined not only to the first end portion 82 and the second end portion 83, but also to the upper bent portion 84 and the lower bent portion 86. The rigidity around the boundary 58 of the side frame 11 is increased, and bending of the side frame 11 can be suppressed. 【0073】 Refer to Figures 8 and 9. Fifth, in the fourth front body structure 10, The side frame 11 consists of a first frame 50 and a second frame 60 that are joined to each other in the vehicle width direction. 【0074】 By joining the crank-shaped reinforcing member 80 to either the first frame 50 or the second frame 60, the frame and the reinforcing member 80 are integrated. Subsequently, by assembling and joining the other frame to the integrated member, the side frame 11 can be manufactured, increasing productivity. 【0075】 Refer to Figures 7 and 8. Sixth, in the first front body structure 10, The structure includes a second connecting member 90 that is joined to both the side frame 11 and the cross member 12, and the second connecting member 90 is joined to the reinforcing member 80. The load applied from the side frame 11 to the reinforcing member 80 can be transmitted from the second connecting member 90 to the bottom member 33, thereby supporting the load. This further suppresses the bending of the side frame 11. 【0076】 Refer to Figure 9. Seventh, in the first front body structure 10, The longitudinal direction of the cross-section of the side frame 11 is the direction of the vehicle height. The side frame 11 is easier to join to the cross member 12. The side frame 11 is less prone to upward bending deformation, so the reinforcing member 80 provided within the cross section is sufficient to prevent upward deformation. Furthermore, the elongated cross section allows for more space in the engine compartment. 【0077】 Refer to Figure 1. Eighth, in the first front body structure 10, Within the cross member 12, the tensile strength of the member to which the reinforcing member 80 is joined (upper cross member 20) is greater than the tensile strength of the side frame 11. The side frame 11 can be preferentially compressed and deformed. As a result, deformation of the rigid members (upper cross member 20 or rear cross member 40) can be suppressed. 【0078】 Refer to Figures 10 and 13. Ninth, in the first front body structure 10, The side frame 11 (for example, the first upper wall portion 53 of the side frame 11) has a shape-changing portion 101 in which the shape changes in the plate thickness direction of the side frame 11 so that the deformation behavior when a compressive load in the vehicle length direction is applied can be controlled. The shape-changing portion 101 is composed of a first protrusion 120 and a second protrusion 130 that protrude from the front side in the thickness direction of the plate, which are arranged alternately adjacent to each other in the length direction of the vehicle. The tip of the first projection 120 is a first inclined ridge 121, where the amount of projection decreases from one end (inner end 122) to the other end (outer end 123). The tip of the second projection 130 is a second inclined ridge 131, the amount of protrusion increasing from one end (inner end 132) to the other end (outer end 133). Viewed along the vehicle's length, the first inclined ridge 121 and the second inclined ridge 131, which are adjacent in the vehicle's length direction, intersect. 【0079】 Within the side frame 11, a first protrusion 120 and a second protrusion 130 are formed adjacent to each other, allowing for the reduction of the load peak and absorption of impact energy. This provides a vehicle body structure with a side frame that has a low deformation load peak, allowing for easy compression deformation. Furthermore, by adjusting the intersection angle θ3 where the first inclined ridge 121 and the second inclined ridge 131 intersect, a larger angle facilitates compression deformation, resulting in a smaller load and longer stroke, while a smaller angle makes compression deformation difficult, resulting in a larger load and shorter stroke. The stroke can be set according to the vehicle type. 【0080】 Refer to Figure 11. Tenth, in the first front body structure 10, Within the first inclined ridge 121, there is a connecting ridge 140 that connects one end (outer end 123) with a small protrusion and the other end (inner end 132) with a small protrusion within the second inclined ridge 131. 【0081】 In addition to the first inclined ridge 121 and the second inclined ridge 131, a connecting ridge 140 is also formed, which is the boundary between the first protrusion 120 and the second protrusion 130. It can be said that the shape-changing section 101 is divided into more fine sections. When a compressive load is applied to the side frame 11, adjacent parts in the longitudinal direction of the vehicle body (the first triangular plane 120a and the second triangular plane 120b of the first protrusion 120, and the first triangular plane 130a and the second triangular plane 130b of the second protrusion 130) undergo continuous compressive deformation. Since the load fluctuation is small and the collapse is stable, the amount of energy absorbed increases. 【0082】 Refer to Figure 12. Eleventh, in the first front body structure 10, The shape-changing section 101 has wavy ridges 100a and 100b at its ends in the vehicle width direction. That is, the shape-changing section 101 collapses stably with little load fluctuation, thus increasing the amount of energy absorbed. 【0083】 Refer to Figures 6 and 13. Twelfth, in the ninth front body structure 10, The side frame 11 (for example, the first frame 50) is A side wall portion (inner wall portion 52) extending upward from the edge of the first lower wall portion 51, It comprises a first upper wall portion 53 extending in the vehicle width direction from inside the side wall portion (inner wall portion 52), At least one of the first upper wall portion 51 and the side wall portion (inner wall portion 52) has a shape-changing portion 101. The first lower wall portion 51 does not have a shape-changing portion 101. 【0084】 Because the side frame 11 has a curved shape, it is prone to bending at the curved portion without being compressed when a collision load is applied. Since the first lower wall portion 51 does not have a shape-changing portion 101, such bending can be suppressed. 【0085】 In addition, the side frame 11 consists of a first frame 50 and a second frame 60 that are joined to each other in the vehicle width direction. By joining the two members, a side frame 11 that is resistant to bending vertically can be constructed. 【0086】 Refer to Figure 14. In addition, the front body structure 10 includes a first frame 50A or a second frame 60A (for example, the second frame 60A) which has a side body portion 210 extending in the vehicle length direction and a rear side portion 220 extending in the vehicle width direction from the end of the side body portion 210 and which can be joined to a cross member. The side body portion 210 has a first ridge line 211 extending in the vehicle length direction, The rear side portion 220 has a second ridge line 221 extending in the vehicle width direction, The first ridge 211 and the second ridge 222 are connected. The load applied to the side frame 11 can be reliably transmitted to the member connected to the cross member (for example, the front pillar). 【0087】 Refer to Figure 10. In addition, the front body structure 10 has a groove (first groove 150) extending in the vehicle width direction in the side wall portion (for example, inner wall portion 52) of the side frame 11. The groove (first groove 150) has shape-changing portions 102, 103 on at least one of the first lower lateral portion 151 and the second upper lateral portion 153 (upper and lower parts) (both in the embodiment). More shape-changing portions 102, 103 can be formed. [Explanation of symbols] 【0088】 10…Front structure of the vehicle 11…Side frame 12…Crossmember 13…Front pillar 50...First frame 51...First lower wall part (lower wall part) 56…Straight lower wall part 57…Slanted lower wall part 58...boundary 60...2nd frame 70…First joint member 80…Reinforcement member 81...Main body 82...First end 83…Second end 84…Upper flexed section 86...Lower bending part 90...Second joining member 101-106...Shape change section 101a, 101b...ridges of the shape change section 120...first protrusion 121...First slope ridgeline 130...Second protrusion 131...Second slope ridgeline 140... Connecting ridge 150…1st groove 151...1st lower horizontal part (lower part) 153...1st upper lateral part (upper part) 160…Second groove 161…Second lower horizontal part (lower part) 163…Second upper horizontal part (upper part) 210...Side body 211...First ridge 220... Rear side section 221...Second Ridge 301-306...Shape change section J1…Joint part J2...upper joint J3…lower joint H1...Height to the upper joint H2...Height to the lower joint

Claims

[Claim 1] A side frame comprising a lower wall portion having a straight lower wall portion extending in the vehicle's longitudinal direction and an inclined lower wall portion extending diagonally downward from the straight lower wall portion, A cross member extending in the width direction of the vehicle, joined to the front pillar and also joined to the side frame, Includes a reinforcing member that reinforces the side frame in order to suppress upward bending of the side frame, The first end of the reinforcing member on the load input side is joined to the boundary between the straight lower wall portion and the inclined lower wall portion. The second end of the reinforcing member opposite to the load input side is joined to the cross member. The reinforcing member is a front structure of the vehicle body that extends diagonally upward from the first end to the second end. [Claim 2] The system includes a first joining member that is joined to both the side frame and the bottom member of the cross member, Using the joint between the lower wall portion of the side frame and the first end portion of the reinforcing member as a reference, The height from the aforementioned joint to the upper joint between the second end of the reinforcing member and the cross member, The height from the aforementioned joint to the lower joint between the first joint member and the bottom member is set to be approximately equal. The front body structure of the vehicle according to claim 1. [Claim 3] The reinforcing member has a crank-shaped cross-section and comprises a main body having a first end and a second end at both ends, an upper bent portion extending upward from one edge of the main body, and a lower bent portion extending downward from the opposite edge of the main body. The front body structure of the vehicle according to claim 1. [Claim 4] The upper bent portion and the lower bent portion of the reinforcing member are joined to the side frame. The front body structure of the vehicle according to claim 3. [Claim 5] The side frame consists of a first frame and a second frame joined to each other in the vehicle width direction. The front body structure of the vehicle according to claim 4. [Claim 6] The system includes a second joining member that is joined to both the side frame and the cross member, The second joining member is joined to the reinforcing member. The front body structure of the vehicle according to claim 5. [Claim 7] The longitudinal direction of the cross-section of the aforementioned side frame is the vehicle height direction. The front body structure of the vehicle according to claim 1. [Claim 8] The tensile strength of the cross member is greater than the tensile strength of the side frame. The front body structure of the vehicle according to claim 1. [Claim 9] The side frame has a shape-changing section in the thickness direction of the side frame so as to control its deformation behavior when a compressive load is applied in the longitudinal direction of the vehicle. The shape-changing portion is composed of a first protrusion and a second protrusion that protrude from the front side in the thickness direction of the plate, which are alternately adjacent to each other in the vehicle length direction. The tip of the first projection is a first inclined ridge whose projection decreases in size from one end to the other. The tip of the second projection is a second inclined ridge whose projection increases in size from one end to the other. When viewed along the vehicle's length, the first and second inclined ridges, which are adjacent in the vehicle's length, intersect. The front body structure of the vehicle according to claim 1. [Claim 10] The first inclined ridge includes a connecting ridge that connects the one end with a small protrusion to the other end with a small protrusion within the second inclined ridge. The front body structure of the vehicle according to claim 9. [Claim 11] The aforementioned shape-changing portion has a wavy ridge at its end in the vehicle width direction. The front body structure of the vehicle according to claim 9. [Claim 12] The aforementioned side frame is A side wall portion extending upward from the edge of the lower wall portion, It comprises an upper wall portion extending in the vehicle width direction from within the side wall portion, At least one of the upper wall portion and the side wall portion has the shape-changing portion, The lower wall portion does not have the shape-changing portion. The front body structure of the vehicle according to claim 9.

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