Vehicle rear frame structure

Abstract

The objective is to obtain a vehicle rear frame structure that can suppress deformation due to thermal deformation during casting and after demolding. [Solution] The rear vehicle frame structure 10 comprises a pair of side member sections 12, each provided on both sides in the vehicle width direction and having a curved section 14 that protrudes upward toward the vehicle; a plurality of cross member sections 16 that are spanned between the pair of side member sections 12 and extend in the vehicle width direction; and one or more connecting sections 22 that connect the cross member sections 16 to each other, provided in the first opening 20A which is long in the vehicle front-rear direction among the plurality of openings 20 surrounded by the pair of side member sections 12 and the pair of cross member sections 16. The structure is integrally molded by casting.

Description

Technical Field

[0001] The present invention relates to a vehicle rear skeleton structure.

Background Art

[0002] Patent Document 1 below discloses a vehicle rear skeleton structure integrally formed by casting. In such a vehicle rear skeleton structure, in many cases, a pair of side member portions provided on both sides in the vehicle width direction and a plurality of cross member portions connecting between the pair of side member portions are integrally formed, and a portion surrounded by the pair of side member portions and the pair of cross member portions is an opening.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a vehicle rear skeleton structure having an opening as described above, the side member portion has an arch shape that protrudes upward of the vehicle in order to support a tire and an axle. In this case, during casting, the side member portion may shrink in a direction to become round due to thermal deformation (thermal shrinkage) after demolding, and there is room for improvement in suppressing deformation.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to obtain a vehicle rear skeleton structure capable of suppressing deformation due to thermal deformation after demolding during casting.

Means for Solving the Problems

[0006] The vehicle rear frame structure according to claim 1 comprises a pair of side member portions provided on both sides in the vehicle width direction and having a curved portion that is convex toward the vehicle upward side; a plurality of cross member portions that are spanned between the pair of side member portions and extend in the vehicle width direction; and one or more connecting portions provided in a first opening that is long in the vehicle longitudinal direction among a plurality of openings surrounded by the pair of side member portions and the pair of cross member portions, and connecting the cross member portions to each other, and is integrally molded by casting.

[0007] In the vehicle rear frame structure according to claim 1, a first opening that is elongated in the vehicle's longitudinal direction, among a plurality of openings surrounded by a pair of side member portions and a pair of cross member portions, is provided with one or more connecting portions that connect the cross member portions to each other. By providing connecting portions in the first opening in this way, deformation due to thermal deformation during casting and after demolding can be suppressed.

[0008] The vehicle rear frame structure according to claim 2 is configured as described in claim 1, wherein the connecting portion extends in the longitudinal direction of the vehicle.

[0009] In the vehicle rear frame structure according to claim 2, since the connecting portion extends in the longitudinal direction of the vehicle, deformation due to thermal deformation after demolding can be suppressed more uniformly.

[0010] The vehicle rear frame structure according to claim 3 is configured according to claim 1 or claim 2, wherein a floor portion that closes a part of the first opening in the vehicle longitudinal direction is integrally molded by casting, and one or more connecting portions are disposed on the lower side of the floor portion.

[0011] In the vehicle rear frame structure according to claim 3, a floor portion that closes a part of the first opening in the vehicle longitudinal direction is integrally molded by casting, and one or more connecting portions are arranged on the lower side of the floor portion, so that deformation due to thermal deformation after demolding can be further suppressed by the floor portion.

[0012] The vehicle rear frame structure according to claim 4, in the configuration according to any one of claims 1 to 3, comprises an extending portion that extends flat toward the first opening from at least a part of the pair of side member portions and the pair of cross member portions surrounding the first opening, and reinforcing ribs are provided on the lower surface of the vehicle of the extending portion.

[0013] In the vehicle rear frame structure according to claim 4, the deformation due to thermal deformation after demolding can be further suppressed by reinforcing ribs provided on the lower surface of the vehicle of the extended portion that extends flat toward the first opening. [Effects of the Invention]

[0014] As described above, the vehicle rear frame structure according to the present invention can suppress deformation due to thermal deformation during casting and after demolding. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic perspective view from an oblique upward side showing the rear frame structure of a vehicle according to the first embodiment. [Figure 2] Figure 1 is a perspective view of the vehicle's rear skeletal structure, seen from a diagonally downward angle. [Figure 3] This is a schematic perspective view from an oblique upward position showing the rear frame structure of a vehicle according to the second embodiment. [Figure 4] Figure 3 is a perspective view of the vehicle's rear skeletal structure, seen from a diagonally downward angle. [Figure 5] This is a schematic perspective view from an oblique upward side showing the rear frame structure of a vehicle according to the third embodiment. [Figure 6] Figure 5 is a perspective view of the vehicle's rear skeletal structure, seen from a diagonally downward angle. [Modes for carrying out the invention]

[0016] <First Embodiment> A vehicle to which a vehicle rear skeleton structure 10 according to a first embodiment of the present invention is applied will be described below with reference to the drawings. In the present specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted. In each drawing, an arrow FR appropriately shown indicates the front side in the vehicle longitudinal direction, and an arrow UP indicates the upper side in the vehicle vertical direction. An arrow LH indicates the left side in the vehicle width direction. Hereinafter, when simply explaining the front and rear, up and down, and left and right directions, unless otherwise specified, the front and rear in the vehicle longitudinal direction, the up and down in the vehicle vertical direction, and the left and right in the vehicle left and right direction (vehicle width direction) are indicated.

[0017] The vehicle to which the vehicle rear skeleton structure 10 according to the first embodiment is applied has, for example, a power unit including a motor, an engine, etc. as a drive source, and is an electric vehicle and a fuel cell vehicle that runs with the power generated by the power unit.

[0018] The vehicle rear skeleton structure 10 as a skeleton part of the vehicle shown in FIGS. 1 and 2 is provided at the rear part of the vehicle and is integrally formed by casting. As shown in FIGS. 1 and 2, the vehicle rear skeleton structure 10 includes a pair of left and right side member parts 12, a pair of left and right wheel house parts 14, and a plurality of cross member parts 16.

[0019] The pair of side member parts 12 are respectively provided on both sides in the vehicle width direction, and each extends in the front-rear direction from the front end to the rear end of the vehicle rear skeleton structure 10. Further, as an example, a wheel house part 14 is formed at the upper part of the substantially central part in the vehicle longitudinal direction of each side member part 12. In the present embodiment, this wheel house part 14 corresponds to a curved part that protrudes upward of the vehicle of the side member part 12.

[0020] Further, the plurality of cross member portions 16 each extend in the vehicle width direction and are installed between the pair of side member portions 12. Specifically, the front end portion of the side member portion 12 is connected by a first cross member portion 16A extending in the vehicle width direction. The first cross member portion 16A is one of the plurality of cross member portions 16.

[0021] The front portion of the wheel house portion 14 is connected by a second cross member portion 16B extending in the vehicle width direction. Also, as shown in FIG. 1, on the upper surface of the vehicle rear portion of the second cross member portion 16B, a third cross member portion 16C that connects the inner side surfaces of the pair of wheel house portions 14 and extends in the vehicle width direction is disposed. As shown in FIG. 2, the second cross member portion 16B and the third cross member portion 16C are in contact with each other. Note that the second cross member portion 16B and the third cross member portion 16C are each one of the plurality of cross member portions 16.

[0022] Also, the rear end portion of the side member portion 12 and the rear portion of the wheel house portion 14 are connected by a fourth cross member portion 16D extending in the vehicle width direction. The fourth cross member portion 16D is one of the plurality of cross member portions 16.

[0023] The vehicle rear skeleton structure 10 includes a plurality of openings 20 surrounded by the pair of side member portions 12 and the pair of cross member portions 16. In the present embodiment, the plurality of openings 20 are, as an example, two. Specifically, the two openings 20 are a second opening 20B surrounded by the pair of side member portions 12, the first cross member portion 16A, and the second cross member portion 16B, and a first opening 20A surrounded by the pair of side member portions 12, the third cross member portion 16C, and the fourth cross member portion 16D.

[0024] Note that in each figure, the width of the opening 20 in the vehicle front-rear direction is, for the sake of convenience, of approximately the same length. However, in the present embodiment, actually, the width of the first opening 20A in the vehicle front-rear direction is formed to be longer than the width of the second opening 20B in the vehicle front-rear direction.

[0025] Furthermore, in this embodiment, the front ends of the pair of side member portions 12 are connected by the first cross member portion 16A, but they do not necessarily have to be connected by the first cross member portion 16A. In this case, the opening 20 will consist only of the first opening 20A.

[0026] The first opening 20A is provided with one or more connecting portions 22 that connect the third cross member portion 16C and the fourth cross member portion 16D. In this embodiment, as an example, the one or more connecting portions 22 are a first connecting portion 22A located on the right side in the vehicle width direction and a second connecting portion 22B located on the left side in the vehicle width direction.

[0027] The connecting portion 22, that is, the first connecting portion 22A and the second connecting portion 22B, extends in the longitudinal direction of the vehicle and is arranged with a gap in the vehicle width direction. Furthermore, the first connecting portion 22A and the side member portion 12, and the second connecting portion 22B and the side member portion 12 are each arranged with a gap in the vehicle width direction.

[0028] Furthermore, the first opening 20A has three rectangular divided openings 24 formed by the first connecting portion 22A and the second connecting portion 22B, with the longitudinal direction of the vehicle being the longitudinal direction. The three divided openings 24 are designated as the first divided opening 24A, the second divided opening 24B, and the third divided opening 24C, in order from the right side in the vehicle width direction.

[0029] The vehicle rear frame structure 10, configured as described above, is integrally molded by casting and includes a pair of side member sections 12, each including a wheelhouse section 14, four cross member sections 16, and two connecting sections 22. In other words, the three divided openings 24 (first divided opening 24A, second divided opening 24B, and third divided opening 24C) and the second opening 20B are not openings that were added later by processing.

[0030] (Mechanism of Action and Effects) Next, the effects and advantages of the first embodiment will be described.

[0031] In the vehicle rear frame structure 10 according to the first embodiment, the first opening 20A, which is longer in the vehicle's longitudinal direction, is provided with one or more connecting parts 22 that connect the third cross member part 16C and the fourth cross member part 16D, among the two openings 20 surrounded by a pair of side member parts 12 and a pair of cross member parts 16. By providing the connecting parts 22 in the first opening 20A in this way, deformation due to thermal deformation during casting and after demolding can be suppressed. Furthermore, by suppressing deformation, productivity during assembly can be improved. In particular, the floor pan (not shown) can be easily assembled at the position corresponding to the first opening 20A.

[0032] Furthermore, in the vehicle rear frame structure 10 according to the first embodiment, since the connecting portion 22 extends in the longitudinal direction of the vehicle, deformation due to thermal deformation after demolding can be suppressed more uniformly.

[0033] Furthermore, the vehicle rear frame structure 10 according to the first embodiment is equipped with a connecting portion 22, which improves rigidity during a rearward collision.

[0034] Furthermore, in the vehicle rear frame structure 10 according to the first embodiment, the connecting portion 22 is provided so that when the floor pan is attached, the connecting portion 22 can receive the load from the seat placed on the floor pan.

[0035] <Second Embodiment> Next, a vehicle rear frame structure 10A according to a second embodiment of the present invention will be described. In the second embodiment, components similar to those of the vehicle rear frame structure 10 of the first embodiment described above are indicated by the same reference numerals, and detailed explanations are omitted here. Only the different components will be described in detail.

[0036] As shown in Figures 3 and 4, the vehicle rear frame structure 10A according to the second embodiment includes a floor portion 26 that closes off a portion of the first opening 20A in the vehicle longitudinal direction, compared to the vehicle rear frame structure 10 of the first embodiment. In this embodiment, for example, the floor portion 26 is formed in a substantially rectangular shape and closes off approximately half of the first opening 20A in the vehicle longitudinal direction. The floor portion 26 is integrally molded by casting together with a pair of side member portions 12, each including a wheelhouse portion 14, four cross member portions 16, and two connecting portions 22.

[0037] The connecting portion 22, that is, the first connecting portion 22A and the second connecting portion 22B, is located on the lower side of the vehicle of the floor portion 26. In this embodiment, as an example, the rear vehicle frame structure 10A is formed so that the floor portion 26 abuts against the upper surfaces of the first connecting portion 22A and the second connecting portion 22B.

[0038] (Mechanism of Action and Effects) Next, the effects and advantages of the second embodiment will be described.

[0039] In the vehicle rear frame structure 10A according to the second embodiment, a floor portion 26 that closes a part of the first opening 20A in the vehicle longitudinal direction is integrally molded by casting, and one or more connecting portions 22 are arranged on the lower side of the floor portion 26. As a result, the floor portion 26 can further suppress deformation due to thermal deformation after demolding.

[0040] <Third Embodiment> Next, a vehicle rear frame structure 10B according to a third embodiment of the present invention will be described. In the third embodiment, components similar to those of the vehicle rear frame structure 10 of the first embodiment described above are indicated by the same reference numerals, and detailed explanations are omitted here. Only the different components will be described in detail.

[0041] As shown in Figures 5 and 6, the vehicle rear frame structure 10B according to the third embodiment includes, for example, an extended portion 28 that extends flat from the third cross member portion 16C to the first opening 20A, compared to the vehicle rear frame structure 10 of the first embodiment.

[0042] As shown in Figure 6, the extended portion 28 is provided with reinforcing ribs 30 on the lower side of the vehicle. In this embodiment, as an example, two ribs 30 are provided, and each is positioned so that its width corresponds to the first connecting portion 22A and the second connecting portion 22B. The ribs 30 are formed in a substantially triangular shape.

[0043] The extended portion 28 and the two ribs 30 are integrally formed by casting together with a pair of side member portions 12, including the wheelhouse portion 14, four cross member portions 16, and two connecting portions 22.

[0044] (Mechanism of Action and Effects) Next, the effects and advantages of the third embodiment will be described.

[0045] In the vehicle rear frame structure 10B according to the third embodiment, the reinforcing ribs 30 provided on the lower surface of the vehicle of the extending portion 28 that extends flat toward the first opening 20A can further suppress deformation due to thermal deformation after demolding. In addition, in this embodiment, since the ribs 30 are provided at a position corresponding to the connecting portion 22, the rigidity of the connecting portion 22 can be increased by the ribs 30.

[0046] <Supplementary explanation> In the above-described embodiment, the rear vehicle frame structures 10, 10A, and 10B are provided with four cross member sections 16, but the present invention is not limited to this, and may have two, three, or even five or more.

[0047] Furthermore, although the vehicle rear frame structures 10, 10A, and 10B in the above-described embodiments are provided with two connecting portions 22, the present invention is not limited to this, and may have one, three, or even four or more.

[0048] Furthermore, although the vehicle rear frame structures 10, 10A, and 10B in the embodiments described above are provided with a wheelhouse portion 14 on the side member portion 12, the present invention is not limited to this, and the wheelhouse portion 14 may not be provided. In this case, the side member portion 12 may be curved so that the side member portion 12 itself is convex toward the upper side of the vehicle.

[0049] Furthermore, although the rear vehicle frame structure 10A of the second embodiment described above has the floor portion 26 provided on the front side of the vehicle, the present invention is not limited to this, and may also have the floor portion 26 provided on the rear side of the vehicle. Also, although the floor portion 26 closes off approximately half of the first opening 20A in the vehicle's longitudinal direction, the present invention is not limited to this, and may close off one-third, or two-thirds, and the extent of closure is not limited.

[0050] Furthermore, although the rear vehicle frame structure 10B of the third embodiment described above is provided with two ribs 30, the present invention is not limited to this, and may be provided with three or more ribs, or with one rib. In addition, the ribs 30 may be arranged so that their position in the vehicle width direction corresponds to the divided opening 24.

[0051] Furthermore, the configuration of the present invention is not limited to the above-described embodiments, and the configuration can be modified as appropriate, as long as the problem can be solved. [Explanation of Symbols]

[0052] 10, 10A, 10B Rear vehicle frame structure 12 Side Member Section 14. Wheel arch section (curved section) 16 Cross member section 20 openings 20A 1st opening 22 Connecting part 26 Floor Area 28 Extension 30 Ribs

Claims

1. A pair of side member sections are provided on both sides in the vehicle width direction, each having a curved portion that protrudes toward the upper side of the vehicle, Multiple cross member sections are installed between the pair of side member sections and extend in the vehicle width direction, Among the multiple openings surrounded by the pair of side member sections and the pair of cross member sections, one or more connecting sections are provided in the first opening which is long in the vehicle's front-rear direction, and which connect the cross member sections to each other. A rear vehicle frame structure that is integrally molded by casting and equipped with [a specific feature].

2. The vehicle rear frame structure according to claim 1, wherein the connecting portion extends in the longitudinal direction of the vehicle.

3. The rear vehicle frame structure according to claim 1, wherein a floor portion that closes a part of the first opening in the vehicle longitudinal direction is integrally molded by casting, and one or more connecting portions are disposed on the lower side of the floor portion.

4. The structure includes an extending portion that extends flat toward the first opening from at least a part of the pair of side member portions and the pair of cross member portions surrounding the first opening, The vehicle rear frame structure according to claim 1, wherein reinforcing ribs are provided on the lower side surface of the vehicle of the extended portion.

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