Vehicle body frame structure

Abstract

To provide a vehicle body frame structure capable of controlling assembly width without any cut and bent parts.SOLUTION: Provided is a vehicle body frame structure 100 comprising a first frame component 1, a second frame component 2, and a third frame component 3 serving as a reinforcing member. The third frame component 3 is fitted inside the first frame component 1 and welded in a posture such that a pair of third flange parts 15 and 16 faces the same direction as a pair of first flange parts 5 and 6. A pair of second flange parts 10 and 11 of the second frame component 2 is fitted inside the pair of first flange parts in a posture facing the pair of first flange parts, brought into abutment with the pair of third flange parts, and welded to the pair of first flange parts.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a body frame structure applied to a vehicle. [Background technology]

[0002] For example, a vehicle body frame structure with a so-called "Monaka" structure is known for vehicles such as pickup trucks and SUVs (Sport Utility Vehicles). This vehicle body frame structure has a first frame component and a second frame component with a U-shaped cross section. The leading edge of the second frame component is fitted inside the leading edge of the first frame component and welded to it. This results in a vehicle body frame structure with a closed cross section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Publication number 3-40698 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, a reinforcing material with a U-shaped cross section may be fitted inside the first frame component and welded in advance. Furthermore, to control the assembly width after assembling the first and second frame components, the first frame component may be provided with a bent portion that bends inward (so-called a lance shape). In this case, a recess is provided in the reinforcing material so that the reinforcing material can pass through the bent portion.

[0005] However, providing the cut and bent portion has the disadvantage of reducing the rigidity of the first frame component, and also complicating the molding process of the reinforcing material because a relief portion must be provided in the reinforcing material.

[0006] The present disclosure has been made in view of the above circumstances, and its purpose is to provide a vehicle body frame structure in which the assembly width can be controlled without providing cut and bent portions. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, A vehicle body frame structure in which a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to the first direction and the second direction are defined, a first frame component extending in the first direction and formed of a metal plate, the first frame component having a first web portion extending in the second direction in a cross-sectional view, and a pair of first flange portions extending from both ends of the first web portion to the same side in the third direction in a cross-sectional view; a second frame component extending in the first direction and formed of a metal plate, the second frame component having a second web portion extending in the second direction in a cross-sectional view and a pair of second flange portions extending from both ends of the second web portion to the same side in the third direction in a cross-sectional view; a third frame component serving as a reinforcing member extending in the first direction and formed of a metal plate, the third frame component having a third web portion extending in the second direction in a cross-sectional view, and a pair of third flange portions extending from both ends of the third web portion to the same side in the third direction in a cross-sectional view; Equipped with the third frame component is fitted and welded to the inside of the first frame component with the pair of third flange portions oriented to face the same side as the pair of first flange portions, The pair of second flange portions are fitted inside the pair of first flange portions in an orientation facing the pair of first flange portions, abutted against the pair of third flange portions, and welded to the pair of first flange portions. A vehicle body frame structure is provided.

[0008] Preferably, recesses and protrusions are formed alternately along the first direction on the tip edges of the pair of third flange portions.

[0009] Preferably, a through hole is formed in the third web portion, and an edge of the through hole is welded to the first web portion.

[0010] Preferably, the through hole is formed by an elongated hole extending in the first direction.

[0011] Preferably, the third web portion has a protruding portion at a middle portion in the second direction in a cross-sectional view, the protruding portion protruding in the third direction away from the first web portion.

[0012] Preferably, a through hole is formed in the third web portion, and an edge of the through hole is welded to the first web portion, A plurality of the through holes are formed above and below the protruding portion along the first direction.

[0013] Preferably, the recessed portion and the protruding portion have the same shape and the same width in the first direction, and are shifted in the first direction by a predetermined pitch, The recess and the protrusion formed on one of the pair of third flange portions and the recess and the protrusion formed on the other are positioned at the same position in the first direction or are positioned offset by the pitch. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide a vehicle body frame structure in which the assembly width can be controlled without providing cut and bent portions. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an exploded perspective view showing a vehicle body frame structure according to an embodiment of the present invention; [Figure 2] FIG. 10 is a perspective view showing a state in which a third frame part is assembled to a first frame part. [Figure 3] FIG. 2 is a perspective view showing a completed axle case structure. [Figure 4] FIG. 10 is a rear view showing the third frame component. [Figure 5] FIG. 4 is a cross-sectional view of FIG. 3 . [Figure 6]6 is a cross-sectional view taken along the line VI-VI in FIG. 3. [Figure 7] 1 is a schematic cross-sectional view showing a vehicle body frame structure according to an embodiment of the present invention. [Figure 8] FIG. 10 is an exploded perspective view showing a vehicle body frame structure of a comparative example. [Figure 9] FIG. 9 is an enlarged perspective view showing a portion IX in FIG. 8. [Figure 10] FIG. 1 is a schematic cross-sectional view showing a vehicle body frame structure of a comparative example. [Figure 11] FIG. 10 is a diagram showing a first modified example. [Figure 12] FIG. 10 is a diagram showing a second modified example. [Figure 13] FIG. 10 is a diagram showing a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to the following embodiments.

[0017] FIG. 1 is an exploded perspective view showing a vehicle body frame structure of this embodiment. The vehicle body frame structure 100 defines a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to the first and second directions. In this embodiment, as shown in the figure, the first direction is the front-to-rear direction, the second direction is the up-down direction, and the third direction is the left-to-right direction. These front-to-rear, left-to-right, up-to-down directions generally coincide with the directions of the vehicle. The vehicle to which the vehicle body frame structure 100 is applied is, but is not limited to, a pickup truck or an SUV. The vehicle body frame structure 100 is applied to a side member of a ladder frame of the vehicle.

[0018] The vehicle body frame structure 100 shown in the drawings is drawn as being relatively short in order to show the essential parts of the structure, but in reality it can be made longer than the illustrated example.

[0019] The vehicle body frame structure 100 includes a first frame component 1, a second frame component 2, and a third frame component 3. These first to third frame components 1 to 3 are assembled in the order shown in Figures 2 and 3 to form the vehicle body frame structure 100 with a so-called monaka structure.

[0020] The first frame component 1 extends in the front-rear direction and is formed from a metal plate (e.g., a steel plate). The first frame component 1 has a U-shaped cross section and includes a first web portion 4 extending in the up-down direction in cross section, and a pair of first flange portions 5, 6 extending from both ends of the first web portion 4 to the same side in the left-right direction (the right side) in cross section. The first frame component 1 is formed by press-forming a metal plate as a raw material. Connection portions 7, 8 between the first web portion 4 and the first flange portions 5, 6 are formed to have a rounded cross section.

[0021] The second frame component 2 is also substantially similar. The second frame component 2 extends in the front-rear direction and is formed from a metal plate (e.g., a steel plate). The second frame component 2 has a U-shaped cross section and includes a second web portion 9 extending in the up-down direction in cross section, and a pair of second flange portions 10, 11 extending from both ends of the second web portion 9 to the same side in the left-right direction (left side) in cross section. The second frame component 2 is formed by press-forming a metal plate as a raw material. Connection portions 12, 13 between the second web portion 9 and the second flange portions 10, 11 are formed to have a rounded cross section.

[0022] The third frame component 3 is also substantially similar. The third frame component 3 extends in the front-rear direction and is formed from a metal plate (e.g., a steel plate). The third frame component 3 has a U-shaped cross section and includes a third web portion 14 that extends in the up-down direction in cross section, and a pair of third flange portions 15, 16 that extend from both ends of the third web portion 14 to the same side in the left-right direction (the right side) in cross section. The third frame component 3 is formed by press-forming a metal plate as a raw material. Connection portions 17, 18 between the third web portion 14 and the third flange portions 15, 16 are formed to have a rounded cross section.

[0023] As described above, the first to third frame components 1 to 3 have an open cross-sectional shape. The first frame component 1 and the second frame component 2 are arranged so that the leading edges of the first flange portions 5, 6 and the second flange portions 10, 11 face each other, in other words, so that their openings face each other. As shown in FIG. 3, the second frame component 2 is fitted inside the first frame component 1 and welded to be assembled. Therefore, as shown in FIG. 1, the height H2 between the outer surfaces of the second flange portions 10, 11 of the second frame component 2 (i.e., the height of the second frame component 2) is equal to or slightly smaller than the height H1 between the inner surfaces of the first flange portions 5, 6 of the first frame component 1. After the second frame component 2 is assembled, the vehicle body frame structure 100 having a closed cross-sectional shape is completed.

[0024] 4 is an enlarged perspective view showing the third frame component 3, FIG. 5 is a cross-sectional view taken along line VV in FIG. 3, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG.

[0025] As shown in Figures 1, 2, and 4 to 6, the third frame component 3 functions as a reinforcing member for reinforcing the first frame component 1. The third frame component 3 is fitted, overlapped, and welded to the inside of the first frame component 1 before the second frame component 2 is assembled (see Figure 2). Therefore, the height H3 (see Figure 1) between the outer surfaces of the third flange portions 15, 16 of the third frame component 3 (i.e., the height of the third frame component 3) is equal to or slightly smaller than the height H1 between the inner surfaces of the first flange portions 5, 6 of the first frame component 1. In other words, the height H3 between the outer surfaces of the third flange portions 15, 16 is equal to the height H2 between the outer surfaces of the second flange portions 10, 11 of the second frame component 2.

[0026] Furthermore, the left-right width W3 of the third frame component 3 is smaller than the distance W1 from the inner surface of the first web portion 4 to the leading edges of the first flange portions 5, 6 in the first frame component 1 (see FIG. 2).

[0027] The length of the third frame component 3 in the front-rear direction is shorter than the length of the first frame component 1, and the third frame component 3 is located in the middle of the first frame component 1 in the front-rear direction (longitudinal direction).

[0028] Recesses 19 and protrusions 20 are formed alternately in the front-rear direction on the leading edge (or free edge) E of the third flange portions 15, 16. The recesses 19 and protrusions 20 are formed simultaneously when the material for the third frame component 3 is punched out by blanking.

[0029] In this embodiment, a plurality of recesses 19 and protrusions 20 are formed on each of the pair of third flanges 15, 16, so that each third flange has three recesses 19 and four protrusions 20. However, the number of recesses 19 and protrusions 20 can be changed.

[0030] As shown in Fig. 5, the recess 19 is formed in a trapezoidal shape, particularly an isosceles trapezoidal shape, in a plan view. The recess 19 is defined by a base portion 21 corresponding to the upper base of the trapezoid and a pair of oblique sides 22 corresponding to a pair of oblique sides of the trapezoid. The portion corresponding to the lower base of the trapezoid is open. In other words, the recess 19 is formed in a trapezoidal shape in which the upper base is closer to the third web portion 14 than the lower base.

[0031] The shape of the protrusions 20 is slightly different between the protrusions 20A located at both ends of the third flange portions 15, 16 in the front-rear direction and the protrusion 20B located in the middle portion.

[0032] The protrusion 20B located in the middle is formed in a trapezoidal shape, particularly an isosceles trapezoid, facing in the opposite direction to the recess 19 in a plan view. The protrusion 20 is defined by an apex 23 corresponding to the upper base of the trapezoid and a pair of oblique sides 22 corresponding to a pair of oblique sides of the trapezoid. In other words, the oblique sides 22 of the recess 19 and the protrusion 20 are shared. The portion corresponding to the lower base of the trapezoid is integrally connected to the third flange portions 15, 16. In other words, the protrusion 20 is formed in a trapezoidal shape in which the lower base is closer to the third web portion 14 than the upper base.

[0033] In the protrusions 20A located at both ends, one of the oblique sides 22A located on the outer side in the front-rear direction (the side away from the center in the front-rear direction) extends in the left-right direction perpendicular to the front-rear direction and is located on the same straight line as the original front and rear end edges of the third flange portions 15, 16. In other respects, it is the same as the protrusion 20B located in the middle portion.

[0034] The front-rear width L1 of the recess 19 is made larger than the front-rear width L2 of the protrusion 20. The reason for this, which will be understood later, is to ensure a long welding length to the first flange portions 5, 6.

[0035] The front-rear direction positions of the recessed portion 19 and the protruding portion 20 in the upper third flange portion 15 are made equal to the front-rear direction positions of the recessed portion 19 and the protruding portion 20 in the lower third flange portion 16. As shown in Fig. 5 , the width center of the front-rear width L1 of the recessed portion 19 is C1, and the width center of the front-rear width L2 of the protruding portion 20 is C2. In this case, the front-rear direction positions of the width centers C1, C2 of the recessed portion 19 and the protruding portion 20 in the upper third flange portion 15 are made equal to the front-rear direction positions of the width centers C1, C2 of the recessed portion 19 and the protruding portion 20 in the lower third flange portion 16.

[0036] A through hole 24 is formed in the third web portion 14. As will be understood later, an edge 26 of this through hole 24 is welded to the first web portion 4. The through hole 24 is formed by an oval long hole extending in the front-rear direction.

[0037] The third web portion 14 has a protruding portion 25 in the middle in the up-down direction in a cross-sectional view, which protrudes in the left-right direction (i.e., protrudes toward the right) away from the first web portion 4. A plurality of (three) through holes 24 are formed above and below this protruding portion 25 in the front-to-rear direction. The protruding portion 25 has a trapezoidal cross section and extends over the entire length of the third web portion 14 in the front-to-rear direction. The protruding portion 25 enhances the rigidity of the first frame component 1.

[0038] Next, a method for assembling the vehicle body frame structure 100 will be described.

[0039] First, as shown in FIG. 2 , the third frame component 3 is fitted inside the first frame component 1 and overlapped. At this time, the third frame component 3 is positioned so that the upper and lower third flange portions 15, 16 face the same side (right side) as the upper and lower first flange portions 5, 6. Then, the third web portion 14 of the third frame component 3 overlaps and contacts the first web portion 4 of the first frame component 1. Furthermore, the upper third flange portion 15 of the third frame component 3 overlaps and contacts the upper first flange portion 5 of the first frame component 1. Furthermore, the lower third flange portion 16 of the third frame component 3 overlaps and contacts the lower first flange portion 6 of the first frame component 1. The third frame component 3 is inserted all the way into the first frame component 1 (to the left).

[0040] Next, the third frame component 3 is welded to the first frame component 1. At this time, the edge 26 of each through hole 24 is fillet-welded along its entire periphery to the first web portion 4. In addition, the bottom portion 21 of each recess 19 in the upper and lower third flange portions 15, 16 is fillet-welded along its entire length to the upper and lower first flange portions 5, 6. This completes the welding of the third frame component 3.

[0041] Additionally or alternatively, the front and rear edge portions of the third web portion 14 may be fillet welded to the first web portion 4. The front and rear edge portions of the upper and lower third flange portions 15, 16 may also be fillet welded to the upper and lower first flange portions 5, 6.

[0042] As shown in Fig. 2, after welding the third frame component 3, a fitting margin 27 for fitting the second frame component 2 is formed in the first flange portions 5, 6 on the right side of the top edge portion 23 of the third frame component 3. Then, as shown in Fig. 3, the tip edges of the second flange portions 10, 11 of the second frame component 2 are fitted into the inside of this fitting margin 27 from right to left.

[0043] At this time, the second frame component 2 is positioned so that the upper and lower second flange portions 10, 11 face the upper and lower first flange portions 5, 6. Furthermore, as shown in FIG. 5 , the leading edge portions 28 of the second flange portions 10, 11 of the second frame component 2 abut against the leading edge portion of the third frame component 3, specifically the top portion 23 of the convex portion 20. This positions the second frame component 2 relative to the first frame component 1, and the assembled width W when the first frame component 1 and the second frame component 2 are assembled is the expected size. The assembled width W is controlled by the position of the leading edge portion of the third frame component 3.

[0044] After the second frame component 2 is fitted, the upper second flange portion 10 of the second frame component 2 is placed on and comes into contact with the upper first flange portion 5 of the first frame component 1. In addition, the lower second flange portion 11 of the second frame component 2 is placed on and comes into contact with the lower first flange portion 6 of the first frame component 1. The second frame component 2 is inserted into the first frame component 1 all the way to the back (left side) where it abuts against the third frame component 3.

[0045] Next, the second frame component 2 is welded to the first frame component 1. At this time, the leading edge portions 28 of the upper and lower second flange portions 10, 11 are fillet-welded over their entire lengths to the upper and lower first flange portions 5, 6. This completes the welding of the second frame component 2, and the vehicle body frame structure 100 is completed.

[0046] 7 shows a schematic cross-sectional view of the vehicle body frame structure 100 taken along a plane perpendicular to the longitudinal direction (corresponding to the VII-VII cross section in FIG. 5). For convenience, the first to third frame components 1 to 3 are depicted as being slightly spaced apart, but as described above, they are in contact with each other and joined by welding. It will be understood that the second frame component 2 is positioned by being abutted against the third frame component 3.

[0047] Next, the effects of this embodiment will be described in comparison with a comparative example.

[0048] 8 to 10 show comparative examples for comparison with this embodiment. Note that parts corresponding to those in this embodiment are basically given the same reference numerals, and descriptions thereof will be omitted.

[0049] This comparative example also has first to third frame components 1 to 3 that are welded together. However, the first flange portions 5, 6 of the first frame component 1 are provided with a plurality (four) of cut and bent portions (so-called lance-shaped) 31 that are abutted against and positioned by the second flange portions 10, 11 of the second frame component 2. The cut and bent portions 31 are formed by making short cuts in parts of the first flange portions 5, 6 and bending the portions located on the first web portion 4 side of the cuts in a concave shape toward the inside of the first frame component 1.

[0050] On the other hand, in order to avoid interference with the cut and bent portion 31 when the third frame component 3 is fitted inside the first frame component 1, multiple (four) relief portions 32 are provided in the third flange portions 15, 16 of the third frame component 3. These relief portions 32 are formed by bending the third flange portions 15, 16 and a part of the third web portion 14 of the third frame component 3 in a concave shape toward the inside of the third frame component 3.

[0051] 10 is a schematic cross-sectional view of a comparative example corresponding to FIG. 7 , showing a schematic cross-sectional view at a position where the cut-and-bending portion 31 and the relief portion 32 are present. In the comparative example, the relief portion 32 passes past the cut-and-bending portion 31, so the third frame component 3 can be inserted all the way into the first frame component 1 until the third web portion 14 of the third frame component 3 abuts against the first web portion 4 of the first frame component 1. The left-right width W3 of the third frame component 3 is set smaller than the distance W1A from the inner surface of the first web portion 4 of the first frame component 1 to the starting end of the cut-and-bending portion 31.

[0052] On the other hand, when the second frame component 2 is fitted inside the first frame component 1, the second flange portions 10, 11 of the second frame component 2 abut against the cut and bent portions 31, thereby positioning the second frame component 2 relative to the first frame component 1 and obtaining the desired assembled width W. The size of the assembled width W is controlled by the positions of the cut and bent portions 31.

[0053] This comparative example has the following drawbacks.

[0054] (1) The provision of the cut and bent portions 31 reduces the rigidity of the first frame component 1. For example, when an axial force (front-rear direction) is applied to the body frame structure 100 due to a vehicle collision or the like, the cut and bent portions 31 may become the starting point of a crack (weak point).

[0055] (2) Since the recess 32 must be provided in the third frame component 3, the molding process of the third frame component 3 becomes complicated.

[0056] On the other hand, this embodiment has the following advantages.

[0057] (1) The second frame component 2 is positioned by abutting it against the third frame component 3, so the cut and bent portion 31 can be omitted. This prevents a decrease in the rigidity of the first frame component 1. Furthermore, the process of forming the cut and bent portion 31 and the jigs, tools, etc. required for this can be omitted.

[0058] (2) The recess 32 can also be omitted from the third frame component 3, simplifying the molding process of the third frame component 3. In addition, jigs, tools, etc., required for the molding process can be omitted.

[0059] As described above, according to this embodiment, it is possible to provide a vehicle body frame structure 100 in which the assembly width W can be controlled without providing the cut and bent portions 31.

[0060] This embodiment also has the following advantages.

[0061] (3) Recessed portions 19 and protruding portions 20 are alternately formed in the front-rear direction on the leading edge portions of the third flange portions 15, 16. Therefore, the recessed portions 19 allow a desired welding length to be obtained, while the protruding portions 20 ensure a necessary and sufficient butting length with the second frame component 2, allowing the welding and butting functions to be appropriately shared.

[0062] In this embodiment, in the recess 19 of the third flange portions 15, 16, only the bottom side 21 is welded, and the oblique side 22 is not welded. Therefore, welding can be performed only at a portion away from the top side 23, preventing spatter from scattering and adhering to the top side 23 during welding. Such spatter deposition on the top side 23 reduces the assembly accuracy or positioning accuracy of the second frame component 2, resulting in an increase in the assembly width W beyond the target value. In this embodiment, preventing spatter from adhering to the top side 23 allows for high assembly accuracy of the second frame component 2 and an increase in the assembly width W. Furthermore, welding can be performed by simply moving the welder linearly along the longitudinal direction (front-to-back direction) of the bottom side 21, thereby shortening the welding time. Conversely, if the oblique side 22 is also to be welded, the welder must be rotated, which increases the welding time.

[0063] (4) A through hole 24 is formed in the third web portion 14, and an edge 26 of the through hole 24 is welded to the first web portion 4. This increases the welding strength, and the surface rigidity of the third web portion 14 can be increased.

[0064] The through-hole 24 is formed as an elongated hole extending in the front-rear direction, that is, in the longitudinal direction of the third frame component 3. This increases the weld length, and further increases the weld strength and surface rigidity.

[0065] The third web portion 14 has a protruding portion 25 that is spaced apart from the first web portion 4. This increases the strength and surface rigidity of the third web portion 14.

[0066] A plurality of through holes 24 are formed in the front-to-rear direction above and below the protruding portion 25. This allows welding to be performed at many locations of the third web portion 14 that contact the first web portion 4, further increasing the welding strength and surface rigidity.

[0067] In this embodiment, when the third frame component 3 is welded to the first frame component 1, the bottom 21 of the recess 19 is welded to the edge 26 of the through hole 24, thereby ensuring sufficient weld strength. Therefore, the front and rear end edges of the third web portion 14 are not welded to the front and rear end edges of the third flange portions 15, 16. However, they may be welded if necessary.

[0068] Next, a modified example will be described.

[0069] 11 shows a first modified example of a third frame component 3 similar to the third frame component 3 of the above embodiment. (B) is a schematic perspective view of the third frame component 3, and (A) shows part of a manufacturing method of the third frame component 3.

[0070] The third frame component 3 is produced by repeatedly blanking a long metal plate (e.g., a steel plate) P having a width LP equal to the front-to-rear length of the third frame component 3, and then bending or otherwise forming each blank 33 thus produced. This is also the case in the above-described embodiment.

[0071] In the blank 33, the portions corresponding to the third flange portions 15, 16 are folded forward (corresponding to the right side) in the thickness direction of the paper at the position of the folding line 34, thereby forming the third frame component 3 having a U-shaped cross section. The recessed portion 19 and the protruding portion 20 are formed simultaneously with the blanking process.

[0072] At both ends of the material 33 in the front-to-rear direction (i.e., the width LP direction), excess length portions 35 having a front-to-rear width LA are provided. Three recesses 19 and two protrusions 20 are alternately formed between these excess length portions 35. The front-to-rear widths L1 and L2 of the recesses 19 and the protrusions 20 are equal (referred to as L3). The recesses 19 and the protrusions 20 are offset from each other in the front-to-rear direction by a predetermined pitch T.

[0073] The extra length portion 35 is a protrusion similar to the protrusion 20, in correspondence with the recess 19 adjacent thereto. This protrusion is a trapezoid with one oblique side perpendicular to the upper and lower bases.

[0074] In this modified example, as in the above embodiment, the recess 19 and protrusion 20 formed on the upper third flange portion 15 and the recess 19 and protrusion 20 formed on the lower third flange portion 16 are each positioned at the same position in the front-to-rear direction.

[0075] In this modified example, the through-hole 24 and the protrusion 25 are omitted, but they may be provided.

[0076] However, this modified example has the following drawback: As shown in Figure 11(A), the recesses 19 and protrusions 20 of adjacent blanks 33 face each other, which causes scrap 36 to be generated between the blanks 33, resulting in a decrease in yield.

[0077] Therefore, in order to overcome this drawback, a second modified example as shown in FIG. 12 was devised.

[0078] In this second modified example, the recesses 19 and protrusions 20 formed on the upper third flange portion 15 and the recesses 19 and protrusions 20 formed on the lower third flange portion 16 are positioned at a pitch T offset in the front-to-rear direction. As a result, as shown in FIG. 12(A), the recesses 19 of one blank 33 and the protrusions 20 of the other blank 33 face each other. These recesses 19 and protrusions 20 have the same shape and are complementary to each other. Therefore, when the recesses 19 and protrusions 20 of one blank 33 are punched, the recesses 19 and protrusions 20 of the other blank 33 are automatically punched, eliminating the generation of scrap 36 between blanks 33. This improves yield.

[0079] In this second modified example, three recesses 19 and two protrusions 20 are alternately formed on the upper third flange portion 15. Two recesses 19 and three protrusions 20 are alternately formed on the lower third flange portion 16. The numbers of recesses 19 and protrusions 20 formed on the upper and lower third flange portions 15, 16 may be reversed. Naturally, the numbers themselves are not limited to a combination of two and three, and other combinations are possible.

[0080] In the lower third flange portion 16, the excess length portion 35 is adjacent to the protrusion 20, and therefore the excess length portion 35 is formed as a recess similar to the recess 19. This recess is also a trapezoid with one oblique side perpendicular to the upper and lower bases.

[0081] On the other hand, this modified example has the following drawback: As described above, in the third flange portions 15, 16, the bottom portions 21 of the recesses 19 are welded to the first flange portions 5, 6. However, since the upper and lower recesses 19 are misaligned in the front-to-rear direction, there is a drawback in that the strength balance after welding is not favorable.

[0082] Therefore, in order to overcome this drawback, a third modified example as shown in FIG. 13 was devised.

[0083] In this third modified example, two types of material are alternately punched out from one long metal plate P: material 33A that is the same as in the first modified example, and material 33B in which the arrangement of the recessed portions 19 and the protruding portions 20 is reversed from material 33 of the first modified example. Accordingly, two types of third frame components are produced from one long metal plate P: third frame component 3A that is the same as in the first modified example, and third frame component 3B in which the arrangement of the recessed portions 19 and the protruding portions 20 is reversed from that of the first modified example.

[0084] In both types of third frame components 3A, 3B, the positions in the front-to-rear direction are the same for the upper recess 19 and the lower recess 19. This makes it possible to achieve a good balance of strength after welding and overcome the drawbacks of the second modified example.

[0085] In this modification, as in the second modification, the recessed portions 19 of one of the adjacent blanks 33A, 33B and the protruding portions 20 of the other blank face each other. These have the same shape and are complementary to each other. Therefore, when the recessed portions 19 and the protruding portions 20 of one blank are punched, the recessed portions 19 and the protruding portions 20 of the other blank are automatically punched, and scrap 36 is not generated between the blanks. This improves the yield.

[0086] Although the embodiments of the present disclosure have been described in detail above, various other embodiments and modifications of the present disclosure are possible.

[0087] (1) For example, only the sides of the edge 26 of the through-hole 24 that are parallel to the front-rear direction may be welded.

[0088] (2) The shape of the through-hole 24 is not limited to an oval shape, but may be, for example, a circle, a square, a rectangle, or the like.

[0089] (3) The protruding portion 25 may be omitted from the third web portion 14, and the through hole 24 may be provided in the middle portion of the third web portion 14 in the vertical direction.

[0090] (4) The shapes of the recessed portions 19 and the protruding portions 20 are not limited to trapezoidal shapes, but may be rectangular or arc-shaped, for example.

[0091] The embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents encompassed within the spirit of the present disclosure as defined by the claims are included in the present disclosure. Therefore, the present disclosure should not be interpreted as being limited, and can be applied to any other technology that falls within the spirit of the present disclosure. [Explanation of symbols]

[0092] 1 First frame part 2 Second frame part 3 Third frame part 4. Web Section 1 5,6 First flange 9. Second Web Section 10,11 Second flange 14 Third Web Section 15,16 Third flange 19 Recess 20 Convex part 24 through holes 25 Protrusion 26 Edge 100 Body frame structure

Claims

1. A vehicle body frame structure in which a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to the first direction and the second direction are defined, a first frame component extending in the first direction and formed of a metal plate, the first frame component having a first web portion extending in the second direction in a cross-sectional view, and a pair of first flange portions extending from both ends of the first web portion to the same side in the third direction in a cross-sectional view; a second frame component extending in the first direction and formed of a metal plate, the second frame component having a second web portion extending in the second direction in a cross-sectional view, and a pair of second flange portions extending from both ends of the second web portion to the same side in the third direction in a cross-sectional view; a third frame component serving as a reinforcing member extending in the first direction and formed of a metal plate, the third frame component having a third web portion extending in the second direction in a cross-sectional view, and a pair of third flange portions extending from both ends of the third web portion to the same side in the third direction in a cross-sectional view; Equipped with the third frame component is fitted and welded to the inside of the first frame component with the pair of third flange portions oriented to face the same side as the pair of first flange portions, The pair of second flange portions are fitted inside the pair of first flange portions in an orientation facing the pair of first flange portions, abutted against the pair of third flange portions, and welded to the pair of first flange portions. A vehicle body frame structure characterized by:

2. The pair of third flange portions have tip edges formed with recesses and protrusions alternately along the first direction. The vehicle body frame structure according to claim 1 .

3. A through hole is formed in the third web portion, and an edge of the through hole is welded to the first web portion. The vehicle body frame structure according to claim 1 .

4. The through hole is formed by a long hole extending in the first direction. The vehicle body frame structure according to claim 3.

5. The third web portion has a protruding portion that protrudes in the third direction away from the first web portion at a middle portion in the second direction in a cross-sectional view. The vehicle body frame structure according to claim 1 .

6. a through hole is formed in the third web portion, and an edge of the through hole is welded to the first web portion; A plurality of the through holes are formed above and below the protruding portion along the first direction. The vehicle body frame structure according to claim 5.

7. the recessed portion and the protruding portion have the same shape and the same width in the first direction, and are shifted in the first direction by a predetermined pitch, The recess and the protrusion formed on one of the pair of third flange portions and the recess and the protrusion formed on the other of the pair of third flange portions are positioned at the same position in the first direction or are positioned with a difference of the pitch. The vehicle body frame structure according to claim 2 .

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