Rear subframe for vehicle

1 . A subframe comprising:

a front cross member extending in a lateral direction of a vehicle body;

two side members symmetrically connected to both rear sides of the front cross member and extending in a longitudinal direction of the vehicle body; and

a rear cross member spaced rearward from the front cross member, extending in the lateral direction of the vehicle body, and connecting the two side members,

wherein each of the two side members comprises a through-hole through which a drive shaft is disposable,

wherein each side member comprises:

a hole cylinder arranged in the through-hole;

a side upper member surrounding an upper side of the hole cylinder and continuously connecting to the front cross member;

a side front member connecting a front side of the hole cylinder and the front cross member and coupled to a lower side of the side upper member;

a side rear member connecting a rear side of the hole cylinder and coupled to the lower side of the side upper member; and

a side lower member surrounding a lower side of the hole cylinder and connecting the side front member and the side rear member.

2 . The subframe of claim 1 ,

wherein the front cross member comprises a front mounting bush at each end portion, and

wherein each of the two side members comprises a rear mounting bush at a rear end portion.

3 . The subframe of claim 2 , wherein each end portion of the front cross member and each rear end portion of the side members extend in a diagonal direction of a rectangle formed by the front cross member, the two side members, and the rear cross member.

4 . The subframe of claim 3 , wherein the two side members are coupled to a rear side, an upper surface, a rear surface, and a lower surface of the front cross member.

5 . The subframe of claim 1 , wherein the side upper member, the side front member, and the side lower member form a structure with multiple closed cross-sections that overlap each other on the front side of the hole cylinder.

6 . The subframe of claim 1 , wherein each end of the rear cross member continuously surrounds an upper surface of a respective side upper member, inward facing surfaces of a respective side upper member and a respective side rear member, and a lower surface of a respective side rear member.

7 . The subframe of claim 1 , further comprising

a lower arm bracket configured to support a lower arm, which extends in the lateral direction of the vehicle body, wherein the lower arm bracket is integrally connected to a lower side of the rear cross member.

8 . The subframe of claim 7 , further comprising

a side lower reinforcement member that connects and supports the lower arm bracket and the side lower member in a front-rear direction of the vehicle body.

9 . The subframe of claim 7 , further comprising

a rear auxiliary arm bracket located behind the rear cross member and connecting and supporting one of the side members and the rear cross member, wherein the rear auxiliary arm bracket is configured to rotatably support a rear auxiliary arm, which extends in the lateral direction of the vehicle body, at a position above and behind the lower arm.

10 . The subframe of claim 1 , further comprising

a front upper bracket located above a connection between the front cross member and each side member, and being supported by both the front cross member and one of the side members, wherein the front upper bracket is configured to rotatably support a front upper arm.

11 . The subframe of claim 1 , wherein an arc-shaped member having a cut out is arranged in the through-hole of each side member.

12 . A subframe comprising:

a front cross member extending in a lateral direction of a vehicle body;

two side members symmetrically connected to both rear sides of the front cross member and extending in a longitudinal direction of the vehicle body; and

a rear cross member spaced rearward from the front cross member, extending in the lateral direction of the vehicle body, and connecting the two side members,

wherein each of the two side members comprises a through-hole through which a drive shaft is disposable, wherein a plurality of arc-shaped members is arranged in the through-hole of each side member.

13 . The subframe of claim 1 , wherein the subframe is a rear subframe.

14 . The subframe of claim 12 , wherein the plurality of arc-shaped members is arranged along a circumferential direction of the through-hole.

15 . The subframe of claim 12 , further comprising a rear upper bracket provided above a middle portion of each side member and configured to support a rotational axis of a rear upper arm.

16 . A subframe comprising:

a front cross member extending in a lateral direction of a vehicle body, wherein the front cross member comprises a front mounting bush at each end portion;

two side members symmetrically connected to both rear sides of the front cross member and extending in a longitudinal direction of the vehicle body, wherein each of the two side members comprises a rear mounting bush at a rear end portion; and

a rear cross member spaced rearward from the front cross member, extending in the lateral direction of the vehicle body, and connecting the two side members,

wherein each of the two side members comprises a through-hole through which a drive shaft is disposable, wherein each side member comprises:

at least one arc-shaped member arranged in the through-hole,

a side upper member surrounding an upper side of the through-hole with the at least one arc-shaped member and continuously connecting the front cross member and the rear mounting bush;

a side front member connecting a front side of the through-hole with the at least one arc-shaped member and the front cross member and coupled to a lower side of the side upper member;

a side rear member connecting a rear side of the through-hole with the at least one arc-shaped member and the rear mounting bush and coupled to the lower side of the side upper member; and

a side lower member surrounding a lower side of the through-hole with the at least one arc-shaped member and connecting the side front member and the side rear member.

17 . The subframe of claim 16 , wherein the side upper member, the side front member, and the side lower member form a structure in which multiple closed cross-sections overlap each other on a front side of the through-hole surrounded by the arc-shaped member.

18 . The subframe of claim 16 , wherein each end of the rear cross member is coupled while continuously surrounding an upper surface of the side upper member, and surfaces of the side upper member and the side rear member located inside the vehicle body, and a lower surface of the side rear member.

19 . The subframe of claim 16 , wherein a lower arm bracket configured to rotatably support a lower arm, which extends in the lateral direction of the vehicle body, is integrally connected to the lower side of the rear cross member.

20 . The subframe of claim 16 , further comprising

a side lower reinforcement member that connects and supports the lower arm bracket and the side lower member in a front-rear direction of the vehicle body.