Underbody for electric vehicle

1. An underbody for an electric vehicle, comprising:

a multiply divided battery mounting portion enabling multiply divided and selective mounting of batteries, and forming a portion of the underbody; and

an underbody portion connected to the battery mounting portion and forming another portion of the underbody,

wherein the multiply divided battery mounting portion comprises:

an upper floor member and a lower floor member defining a battery sliding mounting space; and

a plurality of floor cross members bonded between the upper and lower floor members with predetermined intervals therebetween, and defining at least one battery mounting space, for maintaining strength,

wherein the underbody portion is a reinforcing underbody portion comprising at least a partial extending portion,

wherein the reinforcing underbody portion comprises a front and rear side member bonded to and extending from both sides of a multiply divided battery mounting portion provided as a floor portion, the front and rear side member comprising an extending portion formed on at least a portion thereof for reinforcing strength, and

wherein the side member is bonded to either side floor cross member provided on the multiply divided battery mounting portion provided as a floor portion, and comprises a curved portion for reinforcing strength against bending and a horizontal portion for mounting auxiliary components, and

the extending portion is provided at the bonding portion of the floor cross member.

2. The underbody of claim 1 , wherein the floor cross members bonded between the upper and lower floor members are formed to have at least four sides in a cross-section thereof, for maintaining strength.

3. The underbody of claim 1 , further comprising a guide portion for guiding a battery sliding mount on at least one of the upper and lower floor members or the floor cross members.

4. The underbody of claim 1 , wherein the upper and lower floor members are formed as divided body portions or integrated body portions.

5. The underbody of claim 4 , further comprising a connecting member bonded between the divided body portions.

6. The underbody of claim 1 , wherein the battery mounting space is formed to accommodate the mounting of 3 to 5 batteries therein.

7. The underbody of claim 1 , wherein a plurality of batteries are mounted in the battery mounting space of the multiply divided battery mounting portion, and at least one of the batteries is fixed for providing strength reinforcement between the floor members.

8. The underbody of claim 1 , further comprising at least one replaceable battery and one multipurpose fixed battery mounted on a multiply divided battery mounting portion that is a rearward floor portion of the underbody portion or a reinforcing underbody portion.

9. The underbody of claim 1 , further comprising one or more cross members connected to the front side member and the rear side member for reinforcing respective strength thereof against twisting, wherein the front cross member is provided as a motor mounting member.

10. The underbody of claim 9 , wherein the front side member comprises:

a pillar member bonded thereto and having a side upper member bonded thereto; and

a dash cross side member further connected between the pillar member and the front side member.

11. The underbody of claim 10 , further comprising a shock absorber member and side connecting member bonded between the side upper member and the front side member.

12. The underbody of claim 11 , wherein the members comprised by the underbody are formed as shaped steel members having hollow interiors for reduced weight, and are selectively hydro formed.

13. The underbody of claim 1 , wherein the members comprised by the underbody are formed as shaped steel members having hollow interiors for reduced weight, and are selectively hydro formed.