Refrigerator

1. A refrigerator, comprising:

a main body having a storage room;

a first door hinge-connected to the main body to rotate at a front of one side of the storage room and having an opening;

a second door to rotate at the front of the first door to open and close the opening;

a third door hinge-connected to the main body to rotate at a front of another side of the storage room; and

a rotation guard to rotate while being located at the opening of the first door, the rotation guard including:

a door guard having a rotating shaft, the rotating shaft of the door guard being passable through the opening to connect to a gear, and

a bottom frame located at a lower end of the door guard and movable on a bottom surface of the first door, the bottom frame having an opening, and

wherein the gear rotates in response to a contact with a rack located on the bottom surface of the first door according to a movement of the bottom frame.

2. The refrigerator as claimed in claim 1 , wherein the rotation guard further includes:

side frames extending in a height direction of the refrigerator to be spaced apart from both sides of the door guard and

a top frame located at an upper end of the door guard and connected to one end of the side frames,

wherein the bottom frame has a protruding area protruding toward a front of the storage room, and connected to another end of the side frames, and

the door guard has a plurality of rotating shafts located on a same shaft line.

3. The refrigerator as claimed in claim 2 , wherein the side frames are located to be apart from both sides of the door guard.

4. The refrigerator as claimed in claim 2 , wherein the bottom frame further includes a lock button located at a front surface of the protruding area and when locking of the bottom frame is released by the lock button, the bottom frame moves in a predetermined direction.

5. The refrigerator as claimed in claim 1 , wherein the gear has a plurality of gear teeth and the plurality of gear teeth are disposed at the gear at an angle smaller than 360°.

6. The refrigerator as claimed in claim 1 , wherein the gear has a plurality of gear teeth and some of the plurality of gear teeth has a size smaller than that of other gear teeth.

7. The refrigerator as claimed in claim 1 , wherein a number of gear teeth of the gear corresponds to a moving distance of the rotation guard.

8. The refrigerator as claimed in claim 1 , wherein modules of gear teeth of the rack engaged with the gear teeth of the gear are the same.

9. The refrigerator as claimed in claim 1 , wherein a linear moving distance from a first location of the gear to a second location is shorter than that from the second location of the gear to a third location.

10. The refrigerator as claimed in claim 1 , wherein a rotation direction of the rotation guard is changed depending on locations of the gear and the rack that are engaged with each other.

11. The refrigerator as claimed in claim 1 , wherein in an overall width of the door guard, a width in a direction of the storage room is larger than that in the front of the storage room, with respect to a center of the gear.

12. The refrigerator as claimed in claim 2 , wherein when the second door is closed, the second door has a groove receiving the protruding area.

13. The refrigerator as claimed in claim 12 , wherein the second door includes a fixed door guard that does not overlap the door guard of the rotation guard.

14. The refrigerator as claimed in claim 1 , wherein the storage room includes a fridge or a freezer and the rotation guard is located at at least one of the fridge and the freezer.