Vehicle body structure

Abstract

To provide a vehicle body structure that can improve load absorption efficiency by a side frame and a panel and contributes to development of a sustainable transportation system.SOLUTION: A vehicle body structure Ve includes: an upper panel 17 and a lower panel 18; and a left rear side frame 14 and a right rear side frame 15 that are connected to a vehicle width direction outer side of each panel 17, 18 and extend in a vehicle forward-rearward direction. The left rear side frame 14 has a first stiffness change region 31 and a second stiffness change region 32. The first stiffness change region 31 and the second stiffness change region 32 are provided on an inner side surface 21 and an outer side surface 22 of the left rear side frame 14. The second stiffness change region 32 is provided at a different position in a longitudinal direction from the first stiffness change region 31.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle body structure. [Background technology]

[0002] In recent years, efforts to provide access to sustainable transportation systems have been gaining momentum. To achieve this, research and development is being focused on further improving traffic safety and convenience through development of vehicle body rigidity. For example, a vehicle body structure in which side frames are provided on the left and right sides of the panel in the vehicle width direction and the side frames extend in the vehicle front-rear direction is known.

[0003] The side frame includes a side frame main body and an upper wall member provided on an upper portion of the side frame main body. A plurality of weak portions are formed at intervals in the longitudinal direction (vehicle front-rear direction) on the lower portion of the side frame main body. A folding point is provided on the upper wall member. With this vehicle body structure, when an impact load is input from the front or rear of the vehicle, the side frame is deformed so as to bend in the vertical direction by the weak portions and the folding point, thereby making it possible to absorb the impact load (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-160412 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional technology, since the side frame is deformed in the up-down direction to absorb the impact load, it is difficult to sufficiently deform the panel in relation to the side frame, and therefore there is room for improvement in improving the load absorption efficiency by sufficiently deforming the panel in relation to the side frame.

[0006] An object of the present invention is to provide a vehicle body structure that can improve the load absorption efficiency of side frames and panels, thereby contributing to the development of a sustainable transportation system. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention proposes the following means. (1) The vehicle body structure according to the present invention includes a panel (e.g., upper panel 17, 107 and lower panel 18, 108 in the embodiments) provided under the vehicle, and a side frame (e.g., left rear side frame 14, right rear side frame 15, left front side frame 102, right front side frame 104 in the embodiments) connected to an outer side in the vehicle width direction of the panel (e.g., left outer side portion 17a, 18a in the vehicle width direction and right outer side portion 17b, 18b in the vehicle width direction in the embodiments) and extending in the front-rear direction of the vehicle, and the side frame has a plurality of rigidity members. The side frame has a stiffness change region (e.g., first stiffness change region 31 and second stiffness change region 32 in the embodiment), the multiple stiffness change regions being provided on the vehicle width outer side (e.g., outer surfaces 22, 27 in the embodiment) and the vehicle width inner side (e.g., inner surfaces 21, 26 in the embodiment) of the side frame, and the stiffness change region provided on the vehicle width outer side (e.g., second stiffness change region 32 in the embodiment) is provided at a different position in the longitudinal direction than the stiffness change region provided on the vehicle width inner side (e.g., first stiffness change region 31 in the embodiment).

[0008] With this configuration, rigidity change areas are provided on the outer and inner sides of the side frame in the vehicle width direction. Therefore, when an impact load is applied to the side frame from the front-to-rear direction of the vehicle, the side frame can be deformed so as to bend from the rigidity change areas on the outer and inner sides in the vehicle width direction. The side frame absorbs the applied impact load by deforming in a bending manner.

[0009] Here, the panel is connected to the side frame. Therefore, the side frame bends outward and inward in the vehicle width direction starting from the rigidity change region, and a load is transmitted from the side frame to the panel. Specifically, a load that compresses the panel inward in the vehicle width direction and a load that expands the panel outward in the vehicle width direction are transmitted from the side frame to the panel. Furthermore, a load that deforms the panel in the vehicle front-rear direction is transmitted from the side frame to the panel. This allows the load to be transmitted efficiently over the entire area of ​​the panel, and the entire area of ​​the panel to be deformed appropriately.

[0010] In addition, the stiffness change area on the outer side in the vehicle width direction and the stiffness change area on the inner side in the vehicle width direction are provided at different positions in the longitudinal direction of the side frame, which allows the side frame to be deformed by bending appropriately starting from the stiffness change area without concentrating stress on one part of the side frame. In this way, by deforming the side frame and the entire panel in an appropriate manner, it is possible to improve the load absorption efficiency of the side frame and the panel, which in turn contributes to the development of a sustainable transportation system.

[0011] (2) In the above aspect, the side frame may be provided with weak portions (e.g., the first weak portion 41 to the sixth weak portion 46 in the embodiment) that are continuous in the vehicle width direction on the upper side of the vehicle (e.g., the upper surfaces 23, 28 in the embodiment) and the lower side of the vehicle (e.g., the lower surfaces 24, 29 in the embodiment).

[0012] With this configuration, the weak portion can be deformed together with the rigidity change region on the outer side in the vehicle width direction and the rigidity change region on the inner side in the vehicle width direction, thereby more suitably promoting deformation of the side frame in the vehicle width direction bending from the rigidity change region as a starting point. In addition, the side frame can be prevented from buckling due to stress concentration, and can be bent in the vehicle width direction starting from the rigidity change area. This allows the load to be distributed (transmitted) appropriately over the entire panel. This allows the entire panel to be deformed appropriately by the distributed load.

[0013] (3) In the above aspect, the side frame (e.g., left rear side frame 14 and right rear side frame 15 in the embodiment) may be provided at the rear of the vehicle, and the multiple rigidity change areas may be provided near the rear end of the side frame (e.g., rear portion 14c in the embodiment).

[0014] With this configuration, when an impact load is applied from the rear of the vehicle, the rear end side of the side frame is deformed by bending outward and inward in the vehicle width direction, thereby absorbing the load.

[0015] The rear end sides of the side frames are bent outwardly and inwardly in the vehicle width direction, so that a load is transmitted from the rear end sides of the side frames to the rear end sides of the panel. Specifically, a load that compresses the rear end of the panel inward in the vehicle width direction and a load that stretches it outward in the vehicle width direction are transmitted from the rear end of the side frame to the rear end of the panel. Also, a load that deforms the rear end of the panel toward the front of the vehicle is transmitted from the rear end of the side frame to the panel. This allows the load to be efficiently transmitted from the rear end of the panel to the entire area of ​​the panel.

[0016] In addition, by providing multiple rigidity change regions at the rear end of the side frame, when an impact load is applied from the rear of the vehicle, the rear end of the side frame can be bent in the vehicle width direction before the panel is significantly deformed toward the front of the vehicle, allowing the side frame to absorb the impact load while efficiently transmitting the load to the entire area of ​​the panel. As a result, the impact load can be absorbed by the side frames while being suitably distributed over the entire area of ​​the wide panel, thereby improving the efficiency of load absorption by the panel.

[0017] (4) In the above aspect, the side frame (e.g., the left front side frame 102 and the right front side frame 104 in the embodiment) may be provided at the front of the vehicle, and the multiple rigidity change areas may be provided near the front end of the side frame (e.g., the front portion 102c in the embodiment).

[0018] With this configuration, when an impact load is applied from the front of the vehicle, the load can be absorbed by deforming the front end side of the side frame so as to bend outward and inward in the vehicle width direction.

[0019] The front end portions of the side frames are bent outwardly and inwardly in the vehicle width direction, so that a load is transmitted from the front end portions of the side frames to the front end portions of the panels. Specifically, a load that compresses the front end of the panel inward in the vehicle width direction and a load that stretches it outward in the vehicle width direction are transmitted from the front end of the side frame to the front end of the panel. Also, a load that deforms the front end of the panel toward the rear of the vehicle is transmitted from the front end of the side frame to the panel. This allows the load to be transmitted efficiently from the front end of the panel to the entire area of ​​the panel.

[0020] In addition, by providing multiple rigidity change regions at the front end of the side frame, when an impact load is applied from the front of the vehicle, the front end of the side frame can be bent in the vehicle width direction before the panel is significantly deformed toward the rear of the vehicle, allowing the side frame to absorb the impact load while efficiently transmitting the load to the entire area of ​​the panel. As a result, the impact load can be absorbed by the side frames while being suitably distributed over the entire area of ​​the wide panel, thereby improving the efficiency of load absorption by the panel.

[0021] (5) In the above aspect, the weakened portion and the rigidity changed region may be provided at positions that overlap in the vehicle front-rear direction.

[0022] With this configuration, the weak portion deforms due to an impact load input to the side frame from the front-to-rear direction of the vehicle, thereby facilitating deformation of the side frame in the front-to-rear direction of the vehicle. Here, the weak portion is provided at a position that overlaps (wraps) the rigidity change area in the vehicle longitudinal direction. This makes it possible to prevent stress from concentrating on the rigidity change areas provided at different positions in the longitudinal direction of the side frame. By preventing stress concentration on the rigidity change areas provided at different positions, it is possible to prevent the side frame from buckling in the vehicle longitudinal direction. Therefore, the side frame can be reliably folded outward and inward in the vehicle width direction starting from the rigidity change region, and as a result, a load compressing the panel inward in the vehicle width direction and a load stretching the panel outward in the vehicle width direction can be reliably transmitted from the side frame to the panel. Effect of the Invention

[0023] According to the present invention, the load absorption efficiency of the side frames and panels can be improved, which in turn contributes to the development of a sustainable transportation system. [Brief description of the drawings]

[0024] [Figure 1] 1 is a perspective view of a vehicle body structure according to an embodiment of the present invention, as viewed from the front left side of a vehicle. [Diagram 2] 1 is a side view of a vehicle body structure according to an embodiment of the present invention, as viewed from the left side in a vehicle width direction. [Diagram 3] 1 is a perspective view of a left rear side frame of a vehicle body structure according to an embodiment of the present invention, as viewed from the front left side of the vehicle. FIG. [Figure 4] 2 is a plan view of a left rear side frame of the vehicle body structure according to the embodiment of the present invention, viewed from above. FIG. [Diagram 5] 1 is a plan view illustrating the transmission of an impact load input from the rear of the vehicle to a rear floor structure of a vehicle body structure according to an embodiment of the present invention. [Figure 6] FIG. 13 is a plan view illustrating a front floor structure of a modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, a vehicle body structure according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, an arrow FR indicates the front of the vehicle, an arrow UP indicates the upper side of the vehicle, and an arrow LH indicates the left side of the vehicle.

[0026] Fig. 1 is a perspective view of the vehicle body structure as viewed from the front left side of the vehicle, and Fig. 2 is a side view of the vehicle body structure as viewed from the left side in the vehicle width direction. <Body structure> 1 and 2, a vehicle body structure Ve includes a rear floor structure 10 below a rear luggage compartment 12 at the rear of the vehicle. The rear floor structure 10 includes, for example, a left rear side frame (side frame) 14 and a right rear side frame (side frame) 15 arranged on both sides in the vehicle width direction, a rear bumper beam 16 spanning rear end portions 14b, 15b of the rear side frames 14, 15, an upper panel (panel) 17 provided on upper surfaces 23, 28 of the rear side frames 14, 15, and a lower panel (panel) 18 provided on lower surfaces 24, 29 of the rear side frames 14, 15.

[0027] The left rear side frame 14 is provided at a lower portion on the left side in the vehicle width direction in the rear luggage compartment 12. The left rear side frame 14 extends rearward in the vehicle front-rear direction from a front end portion 14a to a rear end portion 14b. The left rear side frame 14 has an inner surface 21 on the inside in the vehicle width direction, an outer surface 22 on the outside in the vehicle width direction, an upper surface 23 on the upper side of the vehicle, and a lower surface 24 on the lower side of the vehicle. In other words, the inner surface 21 and the outer surface 22 are formed in a state separated on the inside and outside in the vehicle width direction so as not to form the entire circumference of the left rear side frame 14. The left rear side frame 14 is formed into a hollow shape with a rectangular cross section by the inner surface 21, the outer surface 22, the upper surface 23, and the lower surface 24.

[0028] The right rear side frame 15 is provided at the lower right side in the vehicle width direction in the rear luggage compartment 12. The right rear side frame 15 extends rearward from a front end portion 15a to a rear end portion 15b in the vehicle front-rear direction. That is, the right rear side frame 15 extends rearward along the left rear side frame 14. The right rear side frame 15 has an inner surface 26 on the inside in the vehicle width direction, an outer surface 27 on the outside in the vehicle width direction, an upper surface 28 on the upper side of the vehicle, and a lower surface 29 on the lower side of the vehicle. In other words, the inner surface 26 and the outer surface 27 are formed in a state separated on the inner side and the outer side in the vehicle width direction so as not to form the entire circumference of the right rear side frame 15. The right rear side frame 15 is formed into a hollow shape with a rectangular cross section by the inner surface 26, the outer surface 27, the upper surface 28, and the lower surface 29.

[0029] In this embodiment, an example in which the left rear side frame 14 and the right rear side frame 15 are formed as rectangular hollow bodies will be described, but the present invention is not limited to this. As another example, the left rear side frame and the right rear side frame may be formed as rectangular hollow bodies by a frame member with a U-shaped cross section that opens at the top and an upper frame part that closes the top of the frame member. Alternatively, the left rear side frame 14 and the right rear side frame 15 may be formed as circular hollow bodies.

[0030] The rear bumper beam 16 extends in the vehicle width direction. The left rear side frame 14, the right rear side frame 15, and the rear bumper beam 16 are highly rigid members that form the framework of the vehicle body structure Ve (specifically, the rear floor structure 10).

[0031] The upper panel 17 and the lower panel 18 are provided at the bottom of the rear luggage compartment 12 (below the vehicle) and form a floor of the rear luggage compartment 12. Specifically, the upper panel 17 is formed of a plate material that is generally rectangular when viewed from above. A left outer side portion (outside in the vehicle width direction) 17a of the upper panel 17 in the vehicle width direction is connected to an upper surface 23 of the left rear side frame 14 from above the vehicle. A right outer side portion (outside in the vehicle width direction) 17b of the upper panel 17 in the vehicle width direction is connected to an upper surface 28 of the right rear side frame 15 from above the vehicle.

[0032] The lower panel 18 is formed of a plate material that is generally rectangular in top view. A left outer side portion 18a in the vehicle width direction (outside in the vehicle width direction) of the lower panel 18 is connected to a lower surface 24 of the left rear side frame 14 from below the vehicle. A right outer side portion 18b in the vehicle width direction (outside in the vehicle width direction) of the lower panel 18 is connected to a lower surface 29 of the right rear side frame 15 from below the vehicle.

[0033] In other words, the left rear side frame 14 is connected to the vehicle underside surface of the upper panel 17 and the vehicle width direction left outer portion 17a, and also extends in the fore-and-aft direction of the vehicle while being connected to the vehicle overside surface of the lower panel 18 and the vehicle width direction left outer portion 18a. The right rear side frame 15 is connected to the vehicle underside surface of the upper panel 17 and the vehicle width right outer side portion 17b, and extends in the fore-and-aft direction of the vehicle while being connected to the vehicle upper side of the lower panel 18 and the vehicle width right outer side portion 18b.

[0034] In this embodiment, an example in which the rear floor structure 10 is provided with the upper panel 17 and the lower panel 18 will be described, but the present invention is not limited to this. Only the upper panel 17 may be connected to the upper surface 23 of the left rear side frame 14 and the upper surface 28 of the right rear side frame 15. Only the lower panel 18 may be connected to the lower surface 24 of the left rear side frame 14 and the lower surface 29 of the right rear side frame 15.

[0035] <Rear side frame> Fig. 3 is a perspective view of the left rear side frame of the vehicle body structure as viewed from the front left side of the vehicle, and Fig. 4 is a plan view of the left rear side frame of the vehicle body structure as viewed from above. The left rear side frame 14 has a plurality of rigidity change regions 31, 32 and a plurality of weak portions 41 to 46. In the present embodiment, two rigidity change regions, a first rigidity change region 31 and a second rigidity change region 32, are exemplified as the plurality of rigidity change regions 31, 32. The number of rigidity change regions is not limited to two and may be selected arbitrarily.

[0036] The first rigidity change region 31 and the second rigidity change region 32 are provided in the rear portion 14c on the rear end portion 14b side of the left rear side frame 14. The rear portion 14c is located rearward of the center of the left rear side frame 14 in the vehicle front-rear direction and closer to the rear end portion 14b of the left rear side frame 14. Closer to the rear end portion 14b means that the rear portion 14c does not have to be in complete contact with the rear end portion 14b. In this embodiment, the rear portion 14c will be described by taking as an example a range from the rear end portion 14b to a position a predetermined distance forward of the vehicle.

[0037] The first rigidity change region 31 is provided, for example, on the inner surface 21 of the left rear side frame 14 at a position close to the rear end 14b of the left rear side frame 14 that is closest to the rear bumper beam 16. The first rigidity change region 31 is formed so as to be curvedly recessed from the inner surface 21 of the left rear side frame 14 toward the outside in the vehicle width direction (i.e., toward the inside of the left rear side frame 14) and extends in the vehicle up-down direction. Therefore, the first rigidity change region 31 is formed so that the rigidity of the left rear side frame 14 changes in the vehicle front-rear direction.

[0038] The second rigidity change region 32 is provided, for example, on the outer surface 22 of the left rear side frame 14 at a position spaced forward of the vehicle from the first rigidity change region 31. That is, the second rigidity change region 32 is provided at a different position in the longitudinal direction from the first rigidity change region 31. The longitudinal direction refers to the longitudinal direction of the left rear side frame 14 (i.e., the front-rear direction of the vehicle). The second rigidity change region 32 is formed so as to be curvedly recessed from the outer surface 22 of the left rear side frame 14 toward the inside in the vehicle width direction (i.e., toward the inside of the left rear side frame 14) and extends in the vehicle up-down direction. Therefore, the second rigidity change region 32 is formed so that the rigidity of the left rear side frame 14 changes in the vehicle front-rear direction.

[0039] In this manner, the first rigidity change region 31 is provided on the inner surface 21 of the left rear side frame 14. The second rigidity change region 32 is provided on the outer surface 22 of the left rear side frame 14. The first rigidity change region 31 and the second rigidity change region 32 are provided at an interval in the front-rear direction of the vehicle. Therefore, when an impact load is input to the left rear side frame 14 from the rear of the vehicle, the left rear side frame 14 bends outward in the vehicle width direction starting from the first rigidity change region 31. The left rear side frame 14 bends inward in the vehicle width direction starting from the second rigidity change region 32. In other words, the left rear side frame 14 deforms so as to bend outward and inward in the vehicle width direction starting from the first rigidity change region 31 and the second rigidity change region 32.

[0040] In this embodiment, an example will be described in which the first rigidity changed region 31 is provided on the inner surface 21 of the left rear side frame 14, and the second rigidity changed region 32 is provided on the outer surface 22 of the left rear side frame 14, but this is not limiting. As another example, for example, the first rigidity changed region 31 may be provided on the outer surface 22 of the left rear side frame 14, and the second rigidity changed region 32 may be provided on the inner surface 21 of the left rear side frame 14.

[0041] In this embodiment, an example will be described in which the first rigidity change region 31 and the second rigidity change region 32 are formed so as to be curvedly recessed toward the inside of the left rear side frame 14, but the present invention is not limited to this. As another example, the first rigidity change region and the second rigidity change region may be formed so as to protrude toward the outside of the left rear side frame 14. Alternatively, the first rigidity change region and the second rigidity change region may be formed by forming an opening in the left rear side frame 14 or by making the wall thickness (plate thickness) of the left rear side frame 14 different.

[0042] A plurality of weak portions 41 to 46 are provided in the rear portion 14c of the left rear side frame 14. In the present embodiment, six weak portions are exemplified as the plurality of weak portions 41 to 46: a first weak portion 41, a second weak portion 42, a third weak portion 43, a fourth weak portion 44, a fifth weak portion 45, and a sixth weak portion 46. The number of weak portions is not limited to six and may be selected arbitrarily.

[0043] The first weak portion 41, the second weak portion 42, and the third weak portion 43 are provided at intervals in the vehicle front-rear direction on the upper surface 23 of the rear portion 14c of the left rear side frame 14. The first weak portion 41, the second weak portion 42, and the third weak portion 43 are continuous in the vehicle width direction, for example, in a shape that protrudes from the upper surface 23 upward of the vehicle.

[0044] The first weak portion 41 is provided at a position overlapping (wrapping) the first rigidity changing region 31 in both the front-rear direction. For example, in the vehicle width direction, an inner end 41a of the first weak portion 41 is connected to the first rigidity changing region 31, and an outer end 41b is connected to the outer surface 22 of the left rear side frame 14. The inner end 41a of the first weak portion 41 may be separated from the first rigidity changing region 31, and the outer end 41b may be separated from the outer surface 22 of the left rear side frame 14.

[0045] The second weak portion 42 is provided in front of the first weak portion 41, and is provided at a position overlapping (wrapping) the second rigidity changing region 32 in both the front-rear directions. For example, the inner end 42a of the second weak portion 42 is connected to the inner surface 21 of the left rear side frame 14 in the vehicle width direction, and the outer end 42b is connected to the second rigidity changing region 32. The inner end 42a of the second weak portion 42 may be separated from the inner surface 21 of the left rear side frame 14, and the outer end 42b may be separated from the second rigidity changing region 32.

[0046] The third weak portion 43 is provided in front of the second weak portion 42. The distance from the third weak portion 43 to the second weak portion 42 in the vehicle front-rear direction is, for example, the same as the distance between the first weak portion 41 and the second weak portion 42 in the vehicle front-rear direction. For example, the third weak portion 43 has an inner end 43a connected to the inner surface 21 of the left rear side frame 14 and an outer end 43b connected to the outer surface 22 of the left rear side frame 14 in the vehicle width direction. The inner end 43a of the third weak portion 43 may be separated from the inner surface 21 of the left rear side frame 14. The outer end 43b may be separated from the outer surface 22 of the left rear side frame 14.

[0047] The fourth weak portion 44, the fifth weak portion 45, and the sixth weak portion 46 are provided at intervals in the vehicle front-rear direction on the underside 24 of the rear portion 14c of the left rear side frame 14. The fourth weak portion 44, the fifth weak portion 45, and the sixth weak portion 46 are continuous in the vehicle width direction, for example, in a shape that protrudes from the underside 24 downward of the vehicle.

[0048] The fourth weak portion 44 is provided at a position overlapping (wrapping) the first rigidity changing region 31 in the vehicle front-rear direction. The fourth weak portion 44 is formed symmetrically in the up-down direction with respect to the first weak portion 41. Therefore, a detailed description of the fourth weak portion 44 will be omitted.

[0049] The fifth weak portion 45 is provided at a position that overlaps (wraps) the second rigidity changing region 32 at the vehicle front side of the fourth weak portion 44. The fifth weak portion 45 is formed symmetrically in the up-down direction with respect to the second weak portion 42. Therefore, a detailed description of the fifth weak portion 45 will be omitted.

[0050] The sixth weak portion 46 is provided in front of the fifth weak portion 45. The distance in the vehicle front-rear direction between the sixth weak portion 46 and the fifth weak portion 45 is, for example, the same as the distance in the vehicle front-rear direction between the fourth weak portion 44 and the fifth weak portion 45. The sixth weak portion 46 is formed symmetrically in the up-down direction with respect to the third weak portion 43. Therefore, a detailed description of the sixth weak portion 46 will be omitted.

[0051] In the present embodiment, an example has been described in which the first weak portion 41 to the sixth weak portion 46 are formed so as to protrude outward from the left rear side frame 14, but the present invention is not limited to this. As another example, for example, the first weak portion to the sixth weak portion may be formed so as to be curvedly recessed toward the inside of the left rear side frame 14. Alternatively, the first weak portion to the sixth weak portion may be formed by forming an opening in the left rear side frame 14 or by reducing the wall thickness (plate thickness) of the left rear side frame 14.

[0052] 1, the right rear side frame 15 is formed symmetrically with respect to the left rear side frame 14 in the vehicle width direction. For this reason, the multiple rigidity changed regions and multiple weak portions provided in the right rear side frame 15 are given the same reference numerals as the first rigidity changed region 31, the second rigidity changed region 32, and the first weak portion 41 to the sixth weak portion 46 of the left rear side frame 14, and detailed explanations thereof will be omitted.

[0053] Next, with reference to Figs. 2 and 5, an example will be described in which, when an impact load F1 is input to the rear floor structure 10 of the vehicle body structure Ve from the rear of the vehicle, the input impact load F1 is absorbed by the rear floor structure 10. FIG. 5 is a plan view illustrating the transmission of an impact load input from the rear of the vehicle to a rear floor structure of a vehicle body structure.

[0054] 2 and 5, a first rigidity changed region 31 is provided on the inner surface 21 of the left rear side frame 14, and a second rigidity changed region 32 is provided on the outer surface 22 of the left rear side frame 14. The first rigidity changed region 31 is provided on the inner surface 26 of the right rear side frame 15, and the second rigidity changed region 32 is provided on the outer surface 27 of the right rear side frame 15. In this state, an impact load F1 is input to the rear floor structure 10 from the rear of the vehicle.

[0055] When an impact load F1 is input to the rear floor structure 10, the left rear side frame 14 can be deformed so as to be bent outward and inward in the vehicle width direction, starting from the first rigidity change area 31 and the second rigidity change area 32. Similarly, the right rear side frame 15 can be deformed so as to be bent outward and inward in the vehicle width direction, starting from the first rigidity change area 31 and the second rigidity change area 32. The left rear side frame 14 and the right rear side frame 15 are deformed so as to bend, thereby absorbing the input impact load F1.

[0056] Here, an upper panel 17 is connected to an upper surface 23 of the left rear side frame 14 and an upper surface 28 of the right rear side frame 15. A lower panel 18 is connected to a lower surface 24 of the left rear side frame 14 and a lower surface 29 of the right rear side frame 15. The left rear side frame 14 and the right rear side frame 15 deform so as to bend outward and inward in the vehicle width direction, whereby a load is transmitted from the left rear side frame 14 and the right rear side frame 15 to the upper panel 17 and the lower panel 18.

[0057] Specifically, a load F2 that stretches the upper panel 17 and the lower panel 18 outward in the vehicle width direction, and a load F3 that compresses the upper panel 17 and the lower panel 18 inward in the vehicle width direction are transmitted from the left rear side frame 14 and the right rear side frame 15 to the upper panel 17 and the lower panel 18. Furthermore, a load F4 that deforms the upper panel 17 and the lower panel 18 toward the front of the vehicle is transmitted from the left rear side frame 14 and the right rear side frame 15 to the upper panel 17 and the lower panel 18. This allows the load to be efficiently transmitted to the entire area of ​​the upper panel 17 and the lower panel 18, allowing the entire area of ​​the upper panel 17 and the lower panel 18 to deform in a suitable manner.

[0058] In addition, the first rigidity change area 31 and the second rigidity change area 32 of the left rear side frame 14 are provided at different positions in the vehicle front-rear direction. The first rigidity change area 31 and the second rigidity change area 32 of the right rear side frame 15 are provided at different positions in the vehicle front-rear direction. This allows the left rear side frame 14 to be deformed so as to be suitably folded in the vehicle width direction starting from the first rigidity changed region 31 and the second rigidity changed region 32, without concentrating stress on a portion of the left rear side frame 14. The right rear side frame 15 can be deformed so as to be suitably folded in the vehicle width direction starting from the first rigidity changed region 31 and the second rigidity changed region 32, without concentrating stress on a portion of the right rear side frame 15.

[0059] As described above, according to the rear floor structure 10, the left rear side frame 14 and the right rear side frame 15 can be deformed so as to be appropriately folded in the vehicle width direction. In addition, according to the rear floor structure 10, the entire area of ​​the upper panel 17 and the lower panel 18 can be deformed appropriately. This can improve the load absorption efficiency of the left rear side frame 14, the right rear side frame 15, the upper panel 17, and the lower panel 18. This can ultimately contribute to the development of a sustainable transportation system.

[0060] Here, the left rear side frame 14 and the right rear side frame 15 are formed symmetrically. Therefore, hereinafter, only the left rear side frame 14 will be described, and a detailed description of the right rear side frame 15 will be omitted. The left rear side frame 14 is provided on an upper surface 23 with a first weak portion 41, a second weak portion 42, and a third weak portion 43, each of which is continuous in the vehicle width direction. The left rear side frame 14 is provided on a lower surface 24 with a fourth weak portion 44, a fifth weak portion 45, and a sixth weak portion 46, each of which is continuous in the vehicle width direction. Therefore, it is possible to deform the first weak portion 41 to the sixth weak portion 46 together with the first rigidity changing region 31 and the second rigidity changing region 32. This makes it possible to more suitably promote deformation of the left rear side frame 14 in the vehicle width direction starting from the first rigidity changing region 31 and the second rigidity changing region 32.

[0061] Buckling of the left rear side frame 14 due to stress concentration is suppressed, and the left rear side frame 14 can be suitably folded in the vehicle width direction starting from the first rigidity change region 31 and the second rigidity change region 32. This allows the load to be suitably distributed (transmitted) over the entire area of ​​the upper panel 17 and the lower panel 18. This allows the entire area of ​​the upper panel 17 and the lower panel 18 to be suitably deformed by the distributed load.

[0062] A first rigidity change region 31 and a second rigidity change region 32 are provided in the rear portion 14c of the left rear side frame 14. Therefore, when an impact load F1 is input from the rear of the vehicle, the rear portion 14c of the left rear side frame 14 is deformed so as to bend outward and inward in the vehicle width direction, thereby absorbing the load.

[0063] As the rear portion 14c of the left rear side frame 14 bends outward and inward in the vehicle width direction, a load is transmitted from the rear portion 14c of the left rear side frame 14 to the rear end sides of the upper panel 17 and the lower panel 18. Specifically, a load F2 that stretches the rear end sides of the upper panel 17 and the lower panel 18 outward in the vehicle width direction, and a load F3 that compresses the rear end sides of the upper panel 17 and the lower panel 18 inward in the vehicle width direction are transmitted from the rear portion 14c of the left rear side frame 14 to the rear end sides of the upper panel 17 and the lower panel 18. A load F4 that deforms the rear end sides of the upper panel 17 and the lower panel 18 toward the front of the vehicle is transmitted from the rear portion 14c of the left rear side frame 14 to the upper panel 17 and the lower panel 18. This allows the load to be transmitted efficiently from the rear end sides of the upper panel 17 and the lower panel 18 to the entire area of ​​the upper panel 17 and the lower panel 18.

[0064] In addition, a first rigidity change region 31 and a second rigidity change region 32 are provided in the rear portion 14c of the left rear side frame 14. Therefore, when an impact load F1 is input from the rear of the vehicle, the rear portion 14c can be bent in the vehicle width direction before the upper panel 17 and the lower panel 18 are significantly deformed toward the front of the vehicle. This allows the left rear side frame 14 to absorb the impact load F1 while efficiently transmitting the load to the entire area of ​​the upper panel 17 and the lower panel 18. As a result, the impact load F1 can be absorbed by the left rear side frame 14 while the load can be suitably distributed over the entire area of ​​the large-area upper panel 17 and lower panel 18, thereby improving the load absorption efficiency of the upper panel 17 and lower panel 18.

[0065] In addition, the first weak portion 41 and the first rigidity changed region 31 are provided in positions where they overlap in the vehicle front-rear direction. The second weak portion 42 and the second rigidity changed region 32 are provided in positions where they overlap in the vehicle front-rear direction. Therefore, the first weak portion 41 and the second weak portion 42 are deformed by the impact load F1 input to the left rear side frame 14 from the rear of the vehicle, thereby facilitating deformation of the left rear side frame 14 toward the front of the vehicle.

[0066] The first weak portion 41 is provided at a position overlapping the first rigidity change region 31 in the vehicle front-rear direction. The second weak portion 42 is provided at a position overlapping the second rigidity change region 32 in the vehicle front-rear direction. This makes it possible to suppress stress concentration in the first rigidity change region 31 and the second rigidity change region 32, which are provided at different positions in the longitudinal direction of the left rear side frame 14 (i.e., the vehicle body front-rear direction). In this way, by suppressing stress concentration in the first rigidity change region 31 and the second rigidity change region 32, it is possible to suppress buckling of the left rear side frame 14 in the vehicle front-rear direction.

[0067] Therefore, the left rear side frame 14 can be reliably folded outward and inward in the vehicle width direction, starting from the first rigidity change region 31 and the second rigidity change region 32. As a result, the load F2 that stretches the upper panel 17 and the lower panel 18 outward in the vehicle width direction and the load F3 that compresses them inward in the vehicle width direction can be reliably transmitted from the left rear side frame 14 to the upper panel 17 and the lower panel 18.

[0068] [Variations] In this embodiment, an example in which the present invention is applied to a rear floor structure 10 at the rear of a vehicle has been described, but the present invention is not limited to this. As another modified example, the present invention can also be applied to a front floor structure provided at the front of a vehicle. Below, a modified front floor structure 100 will be described with reference to Fig. 6. In the modified example, the same or similar members as those in the rear floor structure 10 of the embodiment are given the same reference numerals and detailed description will be omitted.

[0069] FIG. 6 is a plan view illustrating a front floor structure of a modified example. As shown in Fig. 6, a front floor structure 100 of the modified example is provided at the front of a vehicle. The front floor structure 100 includes a left front side frame (side frame) 102 and a right front side frame (side frame) 104. A front bumper beam 106 is bridged between a front end portion 102a of the left front side frame 102 and a front end portion 104a of the right front side frame 104. An upper panel (panel) 107 is joined from above to the upper surfaces of the left front side frame 102 and the right front side frame 104. In addition, a lower panel (panel) 108 is joined from below to the lower surfaces of the left front side frame 102 and the right front side frame 104.

[0070] The left front side frame 102 is provided at the lower left side in the vehicle width direction in the front of the vehicle. The left front side frame 102 extends from a rear end 102b to a front end 102a toward the front of the vehicle in the vehicle front-rear direction. The first rigidity changed region 31, the second rigidity changed region 32, and the first to sixth weak portions 41 to 46 are provided in a front portion 102c of the left front side frame 102.

[0071] The front portion 102c is located forward of the center of the left front side frame 102 in the vehicle front-rear direction and toward the front end portion 102a of the left front side frame 102. "Close to the front end 102a" means that it does not have to be a position that is completely in contact with the front end 102a. In the modified example, the front portion 102c will be described as a range from the front end 102a to a position a predetermined distance away from the front end 102a toward the rear of the vehicle.

[0072] The right front side frame 104 is formed symmetrically with respect to the left front side frame 102 in the vehicle width direction. For this reason, the multiple rigidity changed regions and multiple weak portions provided in the right front side frame 104 are given the same reference numerals as the first rigidity changed region 31, the second rigidity changed region 32, and the first weak portion 41 to the sixth weak portion 46 of the left front side frame 102, and detailed explanations thereof will be omitted.

[0073] According to the front floor structure 100 of the modified example described above, the left front side frame 102 and the right front side frame 104 can be deformed so as to be appropriately folded in the vehicle width direction. In addition, according to the front floor structure 100, the entire area of ​​the upper panel 107 and the lower panel 108 can be deformed appropriately. This can improve the load absorption efficiency of the left front side frame 102, the right front side frame 104, the upper panel 107, and the lower panel 108. This can ultimately contribute to the development of a sustainable transportation system.

[0074] Here, the left front side frame 102 and the right front side frame 104 are formed symmetrically. Therefore, hereinafter, only the left front side frame 102 will be described, and a detailed description of the right front side frame 104 will be omitted. The first rigidity change region 31 and the second rigidity change region 32 are provided in the front portion 102c of the left front side frame 102. Therefore, when an impact load F5 is input from the front of the vehicle, the load can be absorbed by deforming the front portion 102c of the left front side frame 102 so as to bend outward and inward in the vehicle width direction.

[0075] The front portion 102c of the left front side frame 102 bends outward and inward in the vehicle width direction, so that a load is transmitted from the front portion 102c of the left front side frame 102 to the front end sides of the upper panel 107 and the lower panel 108. That is, a load F6 that stretches the front end sides of the upper panel 107 and the lower panel 108 outward in the vehicle width direction, and a load F7 that compresses the front end sides of the upper panel 107 and the lower panel 108 inward in the vehicle width direction are transmitted from the front part 102c of the left front side frame 102 to the front end sides of the upper panel 107 and the lower panel 108. A load F8 that deforms the front end sides of the upper panel 107 and the lower panel 108 toward the rear of the vehicle is transmitted from the front part 102c of the left front side frame 102 to the upper panel 107 and the lower panel 108. This allows the load to be efficiently transmitted from the front end sides of the upper panel 107 and the lower panel 108 to the entire area of ​​the upper panel 107 and the lower panel 108.

[0076] In addition, the first rigidity change region 31 and the second rigidity change region 32 are provided in the front portion 102c of the left front side frame 102. Therefore, when an impact load F5 is input from the front of the vehicle, the front portion 102c can be bent in the vehicle width direction before the upper panel 107 and the lower panel 108 are significantly deformed toward the rear of the vehicle. This allows the left front side frame 102 to absorb the impact load F5 while efficiently transmitting the load to the entire area of ​​the upper panel 107 and the lower panel 108. As a result, the impact load F5 can be absorbed by the left front side frame 102 while the load can be suitably distributed over the entire area of ​​the large upper panel 107 and lower panel 108, thereby improving the load absorption efficiency of the upper panel 107 and lower panel 108.

[0077] According to the front floor structure 100 of the modified example, it is possible to obtain the same functions and effects as the rear floor structure 10 of the above-mentioned embodiment.

[0078] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0079] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0080] Ve…Body structure 10...Rear floor structure 12…Rear cargo area 14...Left rear side frame (side frame) 14a…Front end of left rear side frame 14b…Rear end of left rear side frame 14c…Rear part of left rear side frame (rear end side) 15...Right rear side frame (side frame) 15a…Front end of right rear side frame 15b…Rear end of right rear side frame 17,107…Upper panel (panel) 17a, 18a... Left outer side in the vehicle width direction (outside of the panel in the vehicle width direction) 17b, 18b... Right outer side in the vehicle width direction (outside of the panel in the vehicle width direction) 18,108…Lower panel (panel) 21, 26…Inner surface (inner side of side frame in the vehicle width direction) 22, 27…Outer surface (outer side of side frame in the vehicle width direction) 23, 28…Top surface (upper side of side frame) 24, 29…Underside (underside of vehicle side frame) 31…First stiffness change area (stiffness change area) 32…Second stiffness change area (stiffness change area) 41…First weak part (weak part) 42…Second weak part (weak part) 43…Third weak part (weak part) 44…Fourth weak part (weak part) 45…5th weak part (weak part) 46…6th weak part (weak part) 100…Front floor structure 102…Left front side frame (side frame) 102a…Front end of left front side frame 102b…Rear end of left front side frame 102c…Front part (rear end side) of left front side frame 104…Right front side frame (side frame) 104a…Front end of right front side frame

Claims

1. A panel provided under the vehicle; A side frame connected to an outer side of the panel in a vehicle width direction and extending in a vehicle front-rear direction; Equipped with The side frame has a plurality of rigidity change regions, The plurality of rigidity change regions are provided on outer and inner sides of the side frames in a vehicle width direction, The rigidity change region provided on the outer side in the vehicle width direction is provided at a position different in the longitudinal direction from the rigidity change region provided on the inner side in the vehicle width direction. A vehicle body structure characterized by:

2. The side frame is provided with a weak portion that is continuous in the vehicle width direction on an upper side and a lower side of the vehicle. The vehicle body structure according to claim 1 .

3. The side frame is provided at the rear of the vehicle, The plurality of rigidity change regions are provided near the rear end of the side frame. The vehicle body structure according to claim 1 .

4. The side frame is provided at the front of the vehicle, The plurality of rigidity change regions are provided near the front end portion of the side frame. The vehicle body structure according to claim 1 .

5. The weakened portion and the rigidity changing region are The vehicle is provided at an overlapping position in the front-rear direction. The vehicle body structure according to claim 2 .

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