Rear structure of vehicle body

Abstract

An embodiment of a rear structure of a vehicle body includes: a lateral extension member connected to both sides of a rear cross member and a rear panel connected to each other; a rear pillar inner lower member connected to a cross beam extension extending in an outward direction of the vehicle body on both sides of the lateral extension member and the rear cross beam member; a wheel cover inner extension member connected to the side wall assembly and the rear pillar inner lower member; and an integral extension member connected to the side wall assembly and to the rear pillar inner lower member and the wheel casing inner extension member.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10 - 2023 - 0182952, filed on December 15, 2023, which is incorporated herein by reference. Technical field

[0003] The present invention relates to a rear structure of a vehicle body. Background art

[0004] Generally, in order to ensure the strength and collision performance of the entire vehicle, a rear pillar (also referred to as a D - pillar by those of ordinary skill in the art) assembly that connects the side - panel assembly and the rear - floor panel is provided at the rear of the vehicle body.

[0005] The design of the rear pillar assembly is an important factor affecting the torsional performance of the vehicle body.

[0006] In recent years, the demand for environmentally friendly vehicles such as electric vehicles and hydrogen vehicles has been increasing, vehicles have become larger, and heavy objects such as battery assemblies are installed at the rear of the vehicle body.

[0007] Therefore, in order to ensure the torsional performance of the vehicle body while supporting a high weight load, it is most important to ensure the joint strength at the rear of the vehicle body and the connection between the respective components of the rear pillar assembly.

[0008] The information included in the background art section is provided to facilitate an understanding of the background of the embodiments of the present invention and may include content unknown in the prior art. Summary of the invention

[0009] The present invention relates to a rear structure of a vehicle body. The detailed description relates to such a rear structure of a vehicle body that strengthens the connection between the respective components at the rear of the vehicle body.

[0010] Embodiments of the present disclosure provide a rear structure of a vehicle body that can ensure the joint strength at the rear of the vehicle body and the connection between components.

[0011] A rear structure of a vehicle body according to an embodiment may include: a laterally extending member connected to both sides of a rear cross - member and a back panel that are connected to each other; an inner - lower rear - pillar member connected to a cross - member extension portion extending in the outward direction of the vehicle body on both sides of the laterally extending member and the rear cross - member; a wheel - house inner - extending member connected to the side - panel assembly and the inner - lower rear - pillar member; and an integral - extending member connected to the side - panel assembly and connected to the inner - lower rear - pillar member and the wheel - house inner - extending member.

[0012] The rear structure according to an embodiment may further include a first box-shaped closed section formed by connecting a laterally extending member, a rear cross member, and a back panel.

[0013] The rear structure according to an embodiment may further include a second box-shaped closed section formed by connecting a lower inner rear pillar member and an integral extension member, and a third box-shaped closed section formed by connecting an inner wheelhouse extension member and the integral extension member.

[0014] The first box-shaped closed section, the second box-shaped closed section, and the third box-shaped closed section may be radially arranged from the connection points where the laterally extending member, the lower inner rear pillar member, and the inner wheelhouse extension member are connected to each other.

[0015] The first box-shaped closed section may be arranged in the vehicle width direction, the second box-shaped closed section may be arranged in the vertical direction, and the third box-shaped closed section may be arranged in the longitudinal direction of the vehicle body.

[0016] The laterally extending member may include: a first flange portion connected to an edge portion of the back panel connected to the rear cross member and connected to the rear floor panel; and a first connection portion connected to the lower inner rear pillar member.

[0017] The lower inner rear pillar member may include a second flange portion connected to the inner wheelhouse extension member.

[0018] The lower inner rear pillar member may include: a second connection portion connected to a cross member extension; and a third connection portion extending upward from the second connection portion and connected to the first connection portion.

[0019] The second connection portion and the third connection portion may be folded in a multi-stage manner in the vertical direction.

[0020] The third connection portion may be connected to the first connection portion on three sides in the longitudinal direction, width direction, and vertical direction of the vehicle body.

[0021] The inner wheelhouse extension member may include a third flange portion formed at a lower end of the inner wheelhouse extension member to be connected to a side body assembly and the lower inner rear pillar member in the longitudinal direction of the vehicle body.

[0022] The inner wheelhouse extension member may include an inner protruding portion protruding in the inward direction of the vehicle body and connected to the side body assembly, the rear floor panel, and the lower inner rear pillar member.

[0023] The inner protruding portion formed in the inner wheelhouse extension member may protrude in the inward direction of the vehicle body and may be connected to the second connection portion and the third connection portion.

[0024] The transverse extension member can form a first box-shaped closed section together with the rear cross member and the back panel.

[0025] The second connecting portion and the third connecting portion can form a second box-shaped closed section together with the integral extension member.

[0026] The internal protruding portion can form a third box-shaped closed section together with the integral extension member.

[0027] While the transverse extension member, the lower inner rear pillar member, the inner wheelhouse extension member, and the side panel assembly are connected to each other, a first assembly process can be performed, in which the second connecting portion is connected to the cross member extension and the third connecting portion is connected to the first connecting portion.

[0028] After the first assembly process, a second assembly process can be performed, in which the integral extension member is connected to the lower inner rear pillar member and the inner wheelhouse extension member.

[0029] The rear structure of the vehicle body according to an embodiment of the present invention can enhance the joint stiffness and connection between the various components of the rear vehicle body.

[0030] In addition, in the detailed description of the embodiments of the present invention, the effects that can be obtained or expected from the embodiments of the present invention are directly or implicitly disclosed. That is, various effects predicted according to the embodiments of the present invention will be disclosed in the detailed description provided later. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These drawings are referred to for explaining the exemplary embodiments of the present invention, and the technical concept of the embodiments of the present invention should not be construed as being limited to the attached drawings.

[0032] Figure 1 and Figure 2 are perspective views showing the rear structure of a vehicle body according to an embodiment.

[0033] Figure 3 and Figure 4 are partial exploded perspective views showing the rear structure of a vehicle body according to an embodiment.

[0034] Figure 5 is a perspective view showing a rear pillar applied to the rear structure of a vehicle body according to an embodiment.

[0035] Figure 6 is a partial exploded perspective view showing the joint structure of a transverse extension member applied to the rear structure of a vehicle body according to an embodiment.

[0036] Figure 7 is Figure 5 a cross-sectional view taken along line A-A in

[0037] Figure 8 is a partially exploded perspective view showing a connection structure of a lower inner rear pillar member applied to a rear structure of a vehicle body according to an embodiment.

[0038] Figure 9 is a partially exploded perspective view showing a connection structure of an inner wheelhouse extension member applied to a rear structure of a vehicle body according to an embodiment.

[0039] Figure 10 is along Figure 5 a sectional view taken along line B - B in

[0040] Figure 11 is along Figure 5 a sectional view taken along line C - C in

[0041] Figure 12 is a view for explaining an assembly process of a rear structure of a vehicle body according to an embodiment.

[0042] The following reference identifiers can be used to describe the various features of the embodiments of the present invention in conjunction with the accompanying drawings.

[0043] 1: Rear end assembly 2: Side panel assembly

[0044] 3: Rear floor panel 4: Wheelhouse member

[0045] 5: Rear cross - member 6: Back panel

[0046] 7: Rear pillar 9: Cross - member extension

[0047] 10: Lateral extension member 11: First flange part

[0048] 13: First connection part 15: First box - shaped closed section

[0049] 21: Upper inner rear pillar member 30: Lower inner rear pillar member

[0050] 31: Second flange part 33: Second connection part

[0051] 35: Third connection part 50: Inner wheelhouse extension member

[0052] 51: Third flange part 53: Inner protruding part

[0053] 70: Integral extension member 71: Second box - shaped closed section

[0054] 73: Third box - shaped closed section S1: First assembly process

[0055] S2: Second assembly process 100: Rear structure of the vehicle body

[0056] It should be understood that the accompanying drawings referred to above are not necessarily drawn to scale, but rather present a rather simplified representation of multiple preferred features showing the basic principles of the embodiments of the present invention. For example, the specific design features (including specific dimensions, orientations, positions, and shapes) of the embodiments of the present invention will be determined in part by the specific intended application and the usage environment. Detailed embodiments

[0057] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those of ordinary skill in the art to which the present invention pertains can easily implement the embodiments of the present invention. As those skilled in the art will recognize, the described embodiments can be modified in many different ways, and all such modifications do not depart from the spirit or scope of the embodiments of the present invention.

[0058] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular forms as used herein are intended to also include the plural forms.

[0059] In addition, in the following detailed description, when components are in a similar relationship, the names of the components are divided into first, second, etc. to distinguish them, and the following description is not necessarily limited to this order.

[0060] As used herein, the terms "comprising" and / or "including" indicate the presence of the specified features, wholes, steps, operations, elements, and / or components, but may also include one or more other features, wholes, or steps. It should also be understood that this does not exclude the presence or addition of elements, operations, components, and / or groups thereof.

[0061] As used herein, the term "and / or" includes any one or all combinations of one or more of the associated listed items.

[0062] In this specification, the term "connection" represents the physical relationship between two components, where the components are directly connected to each other by welding, riveting, self-piercing rivets (SPR), flow drill screws (FDS), structural adhesives, etc., or the components are indirectly connected through one or more intermediate components.

[0063] As used herein, the terms "vehicle", "vehicular", "automobile" or other similar terms as used herein generally refer to passenger vehicles, sports cars, sport utility vehicles (SUVs), buses, trucks, and various commercial vehicles, including passenger cars, hybrid vehicles, electric vehicles, hybrid electric vehicles, purpose-built vehicles based on electric vehicles (PBVs), hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels obtained from energy sources other than petroleum fuels).

[0064] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0065] Figure 1 and Figure 2 is a perspective view showing a rear structure of a vehicle body according to an embodiment.

[0066] Referring Figure 1 and Figure 2 , the rear structure 100 of a vehicle body according to an embodiment can be applied to, for example, the body of a purpose-based moving vehicle (purpose-built vehicle: hereinafter referred to as "PBV").

[0067] The PBV can be used as a living module vehicle based on an electric vehicle, which provides various customized services for users during the movement from a starting point to a destination.

[0068] As an example, the PBV can be manufactured in a box design with a large internal space. In addition, the PBV can have face-to-face seats applied to the internal space.

[0069] The body of the PBV is applicable to various vehicle types with a small number of parts for small-batch production, and can be manufactured in various shapes and sizes.

[0070] In this specification, the "front-rear direction of the vehicle body" can be defined as the longitudinal direction of the vehicle body, the "vehicle width direction" can be defined as the left-right direction of the vehicle body, and the "up-down direction" or "vertical direction" can be defined as the height direction of the vehicle body.

[0071] In addition, in this specification, the "upper end portion", "upper part", or "upper surface" of a component represents the relatively higher end portion, part, or surface of the component in the drawings, and the "lower end portion", "lower part", or "lower surface" of a component represents the relatively lower end portion, part, or surface of the component in the drawings.

[0072] In addition, in this specification, the end portion of a component (e.g., one end portion or the other (other) end portion, etc.) represents the end portion of the component in any direction, and the end portion part of a component (e.g., one end portion part or the other (another) end portion part, etc.) represents the part of the component including the end portion.

[0073] According to an embodiment, a rear structure 100 of a vehicle body may include a rear end assembly 1 that is connected to a rear portion of the vehicle body in the front-rear direction, vehicle width direction, and vertical direction.

[0074] The rear end assembly 1 may be generally applied to rear portions of vehicle bodies of various vehicle types. Here, the various vehicle types refer to various configurations of the rear end assembly 1. For example, the vehicle type may be a hailing vehicle for transporting passengers, a delivery vehicle for transporting goods, and a special vehicle such as an ambulance.

[0075] According to an embodiment of the present invention, the rear structure 100 includes a side panel assembly 2 connected to the rear end assembly 1. The side panel assembly 2 includes a wheelhouse member 4 connected to a rear floor panel 3.

[0076] In addition, the rear end assembly 1 includes a rear cross member 5 installed at a rear end of the rear floor panel 3 in the vehicle width direction. A back panel 6 is installed on the rear cross member 5 in the vehicle width direction.

[0077] The rear end assembly 1 includes a rear pillar 7 configured to support a roof structure (not shown).

[0078] According to an embodiment of the present invention, the rear structure 100 provides a structure capable of ensuring joint strength at the rear of the vehicle body and connections between various components.

[0079] Figure 3 And Figure 4 are partial exploded perspective views showing a rear structure of a vehicle body according to an embodiment.

[0080] Reference Figure 3 And Figure 4 According to an embodiment, the rear structure 100 includes a laterally extending member 10, a lower inner rear pillar member 30, an inner wheelhouse extension member 50, and an integral extension member 70.

[0081] Figure 5 is a perspective view showing a rear pillar applied to a rear structure of a vehicle body according to an embodiment.

[0082] Reference Figures 3 to 5 In an embodiment, the laterally extending member 10 is a member extending from the rear pillar 7 in the vehicle width direction, and the laterally extending member is connected to both sides of the rear cross member 5 and the back panel 6 that are connected to each other.

[0083] Figure 6 is a partial exploded perspective view showing a joint structure of a laterally extending member applied to a rear structure of a vehicle body according to an embodiment.

[0084] Reference Figure 6 According to one embodiment, the laterally extending member 10 includes a first flange portion 11 and a first connecting portion 13.

[0085] The first flange portion 11 is formed on each side of the laterally extending member 10 in the vehicle width direction. The first flange portion 11 is connected to the edge portion of the back panel 6 connected to the rear cross member 5 and connected to the rear floor panel 3 by welding along the vehicle width direction.

[0086] The first connecting portion 13 is formed in a shape corresponding to the shape of the lower inner rear pillar member 30 to be described later. The first connecting portion 13 can be joined to the lower inner rear pillar member 30 by welding.

[0087] Figure 7 is a sectional view taken along line A-A in Figure 5 .

[0088] Reference Figure 6 and Figure 7 According to one embodiment, the rear structure 100 further includes a first boxed closed section 15 that connects the laterally extending member 10, the rear cross member 5, and the back panel 6.

[0089] In other words, the laterally extending member 10 can form the first boxed closed section 15 together with the rear cross member 5 and the back panel 6.

[0090] The first boxed closed section 15 is connected to the lower inner rear pillar member 30 to be described later and is arranged along the vehicle width direction.

[0091] Reference Figures 3 to 5 According to one embodiment, the lower inner rear pillar member 30 is a member that forms the lower part of the rear pillar 7, and the lower inner rear pillar member is joined to the laterally extending member 10 and connected to the inner wheelhouse extension member 50 to be described later.

[0092] In the drawings, reference numeral 21 denotes the upper inner rear pillar member. The upper inner rear pillar member 21 is joined to the lower inner rear pillar member 30 and connected to the side panel assembly 2.

[0093] Figure 8 is a partially exploded perspective view showing the connection structure of the lower inner rear pillar member of the rear structure applied to a vehicle body according to one embodiment.

[0094] Reference Figure 5 and Figure 8 According to one embodiment, the lower inner rear pillar member 30 is connected to the beam extension portion 9 extending in the outward direction of the vehicle body on both sides of the rear cross member 5.

[0095] The lower inner member 30 of the rear pillar includes a second flange portion 31, a second connecting portion 33, and a third connecting portion 35.

[0096] As Figure 5 shown, the second flange portion 31 is formed at the front edge portion of the lower inner member of the rear pillar and is connected to the inner wheelhouse extension member 50 to be described later.

[0097] As Figure 8 shown, the second connecting portion 33 is formed at the lower portion of the lower inner member 30 of the rear pillar and is connected to the cross-member extension 9 of the rear cross-member member 5 in the vehicle width direction.

[0098] Furthermore, the third connecting portion 35 extends upward from the second connecting portion 33 and is connected to the first connecting portion 13 of the lateral extension member 10.

[0099] In one example, the second connecting portion 33 and the third connecting portion 35 are arranged in a shape that is folded in multiple stages along the vertical direction.

[0100] The third connecting portion 35 can be joined to the first connecting portion 13 of the lateral extension member 10 by welding on three sides in the longitudinal direction, vehicle width direction, and vertical direction of the vehicle body.

[0101] Referring Figures 3 to 5 , in one embodiment, the inner wheelhouse extension member 50 is located on both sides of the rear structure 100 and is connected to the wheelhouse member 4 of the side body assembly 2 in the longitudinal direction of the vehicle body.

[0102] Furthermore, the inner wheelhouse extension member 50 is connected to the lower inner member 30 of the rear pillar.

[0103] Figure 9 is a partially exploded perspective view showing the connection structure of the inner wheelhouse extension member applied to the rear structure of a vehicle body according to one embodiment.

[0104] Referring Figure 5 and Figure 9 , the inner wheelhouse extension member 50 according to one embodiment includes a third flange portion 51 and an inner protruding portion 53.

[0105] The third flange portion 51 is formed at the lower end of the inner wheelhouse extension member 50 to engage with the side body assembly 2 and the lower inner member 30 of the rear pillar in the longitudinal direction of the vehicle body.

[0106] Furthermore, the inner protruding portion 53 extends upward from the third flange portion 51. The inner protruding portion 53 is formed to protrude from the inner wheelhouse extension member 50 in the inward direction of the vehicle body. Those of ordinary skill in the art also refer to the inner protruding portion 53 as an "inner forming portion".

[0107] The inner protruding portion 53 can be joined to the side wall assembly 2, the rear floor panel 3, and the lower inner member 30 of the rear pillar along the longitudinal direction of the vehicle body. In addition, the inner protruding portion 53 can be joined to the second connecting portion 33 and the third connecting portion 35 of the lower inner member 30 of the rear pillar.

[0108] Reference Figure 3 And Figure 4 , in one embodiment, the integral extension member 70 is connected to the side wall assembly 2.

[0109] The integral extension member 70 can be generally applied to the rear body of a car-sharing vehicle and a delivery vehicle.

[0110] Reference Figure 3 , Figure 4 , Figure 8 And Figure 9 , according to one embodiment, the integral extension member 70 is connected to the lower inner member 30 of the rear pillar and the inner wheelhouse extension member 50.

[0111] The integral extension member 70 can be joined to the lower inner member 30 of the rear pillar and the inner wheelhouse extension member 50 as a single member along the vehicle width direction.

[0112] Figure 10 Is a sectional view taken along line B-B in Figure 5 .

[0113] Reference Figure 3 And Figure 10 , according to one embodiment, the rear structure 100 further includes a second box-shaped closed section 71 that connects the lower inner member 30 of the rear pillar and the integral extension member 70.

[0114] In other words, as shown in Figure 8 , the second connecting portion 33 and the third connecting portion 35 of the lower inner member 30 of the rear pillar can form the second box-shaped closed section 71 together with the integral extension member 70.

[0115] The second box-shaped closed section 71 is connected to the laterally extending member 10 and the inner wheelhouse extension member 50, and is arranged along the vertical direction.

[0116] Figure 11 Is a sectional view taken along line C-C in Figure 5 .

[0117] Reference Figure 3 And Figure 11 , according to one embodiment, the rear structure 100 further includes a third box-shaped closed section 73 that connects the inner wheelhouse extension member 50 and the integral extension member 70.

[0118] In other words, as shown in Figure 9 shown, the inner protruding portion 53 of the wheelhouse inner extension member 50 can form a third box-shaped closed section 73 together with the integral extension member 70.

[0119] The third box-shaped closed section 73 is connected to the lower inner member 30 of the rear pillar and is arranged along the longitudinal direction of the vehicle body.

[0120] As shown in Figure 7 shown, the first box-shaped closed section 15, as shown in Figure 10 shown, the second box-shaped closed section 71, and as shown in Figure 11 shown, the third box-shaped closed section 73 are arranged radially, as shown in Figure 5 shown.

[0121] The first box-shaped closed section 15, the second box-shaped closed section 71, and the third box-shaped closed section 73 can be arranged radially from the joint point JP where the lateral extension member 10, the lower inner member 30 of the rear pillar, and the wheelhouse inner extension member 50 are joined.

[0122] Figure 12 is a view for explaining the assembly process of the rear structure of a vehicle body according to an embodiment.

[0123] Hereinafter, with reference to Figures 1 to 12 the assembly process and operation of the rear structure 100 configured as described above according to an embodiment will be described in detail.

[0124] With reference to Figures 1 to 12 , in one embodiment, the lateral extension member 10 is connected to each side of the rear cross member 5 and the back panel 6, respectively.

[0125] In a separate process, through the first flange portion 11, the lateral extension member 10 is connected to the edge portion of the back panel 6 and connected to the rear floor panel 3 by welding along the vehicle width direction.

[0126] At the same time, in one embodiment, in another process, the upper inner member 21 and the lower inner member 30 of the rear pillar, which are connected to each other, are connected to the side body assembly 2.

[0127] The wheelhouse inner extension member 50 is joined to the side body assembly 2 and connected to the second flange portion 31 of the lower inner member 30 of the rear pillar.

[0128] Therefore, as described above, the lateral extension member 10, the lower inner member 30 of the rear pillar, the wheelhouse inner extension member 50, and the side body assembly 2 are connected to each other.

[0129] In this state, the lower inner rear pillar member 30 is connected to the cross member extension portion 9 of the rear cross member 5 and to the lateral extension member 10. Moreover, the inner wheelhouse extension member 50 and the side panel assembly 2 are connected to the rear floor panel 3.

[0130] Connect the second connection portion 33 of the lower inner rear pillar member 30 to the cross member extension portion 9. Moreover, connect the third connection portion 35 of the lower inner rear pillar member 30 to the first connection portion 13 of the lateral extension member 10.

[0131] Connect the third connection portion 35 to the first connection portion 13 of the lateral extension member 10 by welding on three sides along the longitudinal direction, vehicle width direction, and vertical direction of the vehicle body.

[0132] As Figure 12 shown, after performing the series of first assembly processes S1 described above, a second assembly process S2 is performed, in which the integral extension member 70 is connected to the lower inner rear pillar member 30 and the inner wheelhouse extension member 50.

[0133] Therefore, according to an embodiment of the rear structure 100 assembled as described above, a first box-shaped closed section 15 connecting the lateral extension member 10, the rear cross member 5, and the back panel 6 is formed.

[0134] In addition, according to the rear structure 100 of an embodiment assembled as described above, a second box-shaped closed section 71 connecting the lower inner rear pillar member 30 and the integral extension member 70 is formed, and a third box-shaped closed section 73 connecting the inner wheelhouse extension member 50 and the integral extension member 70 is formed.

[0135] In addition, according to the rear structure 100 of an embodiment, the first box-shaped closed section 15, the second box-shaped closed section 71, and the third box-shaped closed section 73 described above are radially connected together along the longitudinal direction, vehicle width direction, and vertical direction of the vehicle body.

[0136] In addition, according to the embodiment of the rear structure 100, the lateral extension member 10 and the lower inner rear pillar member 30 are connected by a three-sided joining method.

[0137] Therefore, according to the rear structure 100 of an embodiment, the closed section coefficient in the longitudinal direction, vehicle width direction, and vertical direction of the vehicle body can be increased, thereby improving the rear strength of the vehicle body and strengthening the connection between components.

[0138] In addition, according to the rear structure 100 of an embodiment, the torsional performance of the vehicle can be improved by strengthening the joining strength and connection performance of the rear part of the vehicle body.

[0139] In addition, the rear structure 100 according to an embodiment can improve the NVH performance of the vehicle and effectively disperse the collision load when a collision occurs at the rear of the vehicle.

[0140] Although embodiments of the present invention have been described in conjunction with presently considered practical exemplary embodiments, it should be understood that the embodiments of the present invention are not limited to the disclosed embodiments. On the contrary, they are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A rear structure of a vehicle body, the rear structure comprising: a transverse extension member connected to both sides of the rear cross member and the back panel connected to each other; a rear pillar inner lower member connected on both sides of the lateral extension member and the rear cross member to a cross member extension extending in an outward direction of the vehicle body; A wheel house inner extension member connected to the side panel assembly and the rear pillar inner lower member; as well as An integral extension member is connected to the side enclosure assembly and to the rear pillar inner lower member and the wheel house inner extension member. 2 . The rear structure according to claim 1 , further comprising a first box-shaped closed section defined by connection of the lateral extending member, the rear cross member and the back panel.

3. The rear structure according to claim 2, further comprising: a second box-shaped closed section defined by the connection of the rear pillar inner lower member and the integral extension member; as well as A third box-shaped closed section is defined by the connection between the wheel house inner extension member and the integral extension member.

4. The rear structure according to claim 3, wherein: The first box-shaped closed section, the second box-shaped closed section, and the third box-shaped closed section are radially arranged from a connection point where the lateral extending member, the rear pillar inner lower member, and the wheel house inner extending member are connected to each other.

5. The rear structure according to claim 4, wherein: The first box-shaped closed section is arranged along the vehicle width direction; The second box-shaped closed section is arranged along the vertical direction; and The third box-shaped closed section is arranged along the front-rear direction of the vehicle body.

6. The rear structure according to claim 1, wherein: The rear pillar inner lower member includes a second flange portion connected to the wheel house inner extension member.

7. The rear structure according to claim 1, wherein: The wheel house inner extension member includes a third flange portion disposed at a lower end of the wheel house inner extension member to be connected to the side panel assembly and the rear pillar inner lower member in a front-rear direction of the vehicle body.

8. The rear structure according to claim 1, wherein: The wheel house inner extension member includes an inner protruding portion that protrudes in an inward direction of the vehicle body and is connected to the side panel assembly, the rear floor panel, and the rear pillar inner lower member.

9. A rear structure of a vehicle body, the rear structure comprising: a transverse extension member connected to both sides of the rear cross member and the back panel connected to each other; a rear pillar inner lower member connected on both sides of the lateral extension member and the rear cross member to a cross member extension extending in an outward direction of the vehicle body; A wheel house inner extension member connected to the side panel assembly and the rear pillar inner lower member; as well as an integral extension member connected to the side enclosure assembly and to the rear pillar inner lower member and the wheel house inner extension member; and Wherein, the transversely extending member comprises: a first flange portion connected to an edge portion of the back panel connected to the rear cross member and connected to a rear floor panel; and The first connecting portion is connected to the inner lower member of the rear pillar.

10. The rear structure according to claim 9, wherein: The rear pillar inner lower component comprises: a second connecting portion connected to the cross-beam extension; and A third connection portion extends upward from the second connection portion and is connected to the first connection portion.

11. The rear structure according to claim 10, wherein: The second connection portion and the third connection portion are folded in a multi-stage manner along a vertical direction.

12. The rear structure according to claim 10, wherein: The third connection portion is connected to the first connection portion on three sides along the front-rear direction, the width direction, and the vertical direction of the vehicle body. 13 . The rear structure according to claim 10 , further comprising an inner protrusion that is arranged in the wheel house inner extension member, protrudes in an inward direction of the vehicle body, and is connected to the second connection portion and the third connection portion.

14. The rear structure according to claim 13, wherein: The transversely extending member defines a first box-shaped closed section together with the rear cross member and the back panel; The second connecting portion and the third connecting portion together with the integral extension member define a second box-shaped closed section; as well as The inner protruding portion together with the integral extension member defines a third box-shaped closed section.

15. A method for assembling a rear structure of a vehicle body, the method comprising: connecting a transversely extending member to both sides of the rear cross member and the back panel connected to each other, wherein a first flange portion of the transversely extending member is connected to an edge portion of the back panel and to the rear floor panel; Connecting a rear pillar inner lower member to a cross member extension extending in an outward direction of the vehicle body at both sides of the lateral extension member and the rear cross member, wherein a first connection portion of the lateral extension member is connected to the rear pillar inner lower member; Connecting the wheel house inner extension member to the side panel assembly and the rear pillar inner lower member; connecting an integral extension member to the side enclosure assembly; and A first assembly process is performed in a state where the lateral extension member, the rear pillar inner lower member, the wheel house inner extension member, and the side enclosure assembly are connected to each other. In the first assembly process, a second connection portion of the rear pillar inner lower member is connected to the cross beam extension, and a third connection portion of the rear pillar inner lower member extending upward from the second connection portion is connected to the first connection portion.

16. The method according to claim 15, wherein: After performing the first assembly process, the method further includes performing a second assembly process in which the integrated extension member is connected to the rear pillar inner lower member and the wheel house inner extension member.

17. The method according to claim 16, wherein: A first box-shaped closed section is formed connecting the lateral extending member, the rear cross member and the back panel.

18. The method of claim 17, wherein: forming a second box-shaped closed section connecting the rear pillar inner lower member and the integral extension member; and A third box-shaped closed section is formed connecting the wheel house inner extension member and the integral extension member.

19. The method according to claim 18, wherein: The first box-shaped closed section, the second box-shaped closed section, and the third box-shaped closed section are radially connected together along the front-rear direction, the vehicle width direction, and the vertical direction of the vehicle body.

20. The method according to claim 19, wherein: The transverse extension member and the rear pillar inner lower member are connected by three-side combination.

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