Refrigerator having hinge and damper

1 . A refrigerator comprising:

a cabinet having a storage space;

a door configured to open and close the cabinet;

a hinge configured to connect the door to the cabinet to rotatably support the door; and

a damper configured to provide a damping force to the door while the door rotates from an open position to a closed position, the damper configured to vary the damping force while the door rotates from the open position to the closed position,

wherein the damper includes:

a housing having a space;

a cylinder configured to move in the space of the housing while in contact with the door or the cabinet, the cylinder having a space to accommodate oil therein;

a piston configured to move within the space of cylinder as the cylinder moves, the piston having an orifice through which the oil passes; and

an elastic member configured to provide elastic force to the piston,

wherein the cylinder includes a first portion having an inner diameter, a second portion having an inner diameter greater than the inner diameter of the first portion, and at least one rib protruding from an inner circumferential surface of the second portion,

wherein, when the piston is within the second portion, the piston contacts the at least one rib,

wherein a first damping force is generated when the piston is positioned within the first portion, and

wherein a second damping force is generated when the piston is positioned within the second portion.

2 . The refrigerator of claim 1 , wherein the second portion includes:

a first section in which the inner diameter increases from a first position adjacent the first portion to a second position spaced from the first portion; and

a second section extending from the first section, the inner diameter of the second section being constant.

3 . The refrigerator of claim 1 , wherein the at least one rib includes a plurality of ribs spaced apart from one another in a circumferential direction of the second portion.

4 . A refrigerator comprising:

a cabinet having a storage space;

a door configured to open and close the cabinet;

a hinge configured to connect the door to the cabinet to rotatably support the door; and

a damper configured to provide a damping force to the door while the door rotates from an open position to a closed position, the damper configured to vary the damping force while the door rotates from the open position to the closed position,

wherein the damper includes:

a housing having a space;

a cylinder configured to move in the space of the housing while in contact with the door or the cabinet, the cylinder having a space to accommodate oil therein; and

a piston configured to move within the space of cylinder as the cylinder moves, the piston having an orifice through which the oil passes,

wherein the cylinder includes a first portion having an inner diameter, a second portion having an inner diameter greater than the inner diameter of the first portion, and at least one rib protruding from an inner circumferential surface of the second portion,

wherein the second portion includes:

a first section in which the inner diameter increases from a first position adjacent the first portion to a second position spaced from the first portion; and

a second section extending from the first section, the inner diameter of the second section being constant,

wherein, when the piston is within the second portion, the piston contacts the at least one rib,

wherein a first damping force is generated when the piston is positioned within the first portion, and

wherein a second damping force is generated when the piston is positioned within the second portion.

5 . The refrigerator of claim 4 , wherein the at least one rib includes a plurality of ribs spaced apart from one another in a circumferential direction of the second portion.

6 . A refrigerator comprising:

a cabinet having a storage space;

a door configured to open and close the cabinet;

a hinge configured to connect the door to the cabinet to rotatably support the door; and

a damper configured to provide a damping force to the door while the door rotates from an open position to a closed position, the damper configured to vary the damping force while the door rotates from the open position to the closed position,

wherein the damper includes:

a housing having a space;

a cylinder configured to move in the space of the housing while in contact with the door or the cabinet, the cylinder having a space to accommodate oil therein; and

a piston configured to move within the space of cylinder as the cylinder moves, the piston having an orifice through which the oil passes; and

at least one rib protruding from an inner circumferential surface of the cylinder,

wherein the piston is configured to come into contact with the at least one rib over at least portion of a movement path of the cylinder,

wherein the cylinder includes a first portion having an inner diameter, and a second portion having an inner diameter greater than the inner diameter of the first portion,

wherein a first damping force is generated when the piston is positioned within the first portion, and

wherein a second damping force is generated when the piston is positioned within the second portion.

7 . The refrigerator of claim 6 , wherein the damper further includes an elastic member configured to provide elastic force to the piston.

8 . The refrigerator of claim 7 , wherein the second portion includes:

a first section in which the inner diameter increases from a first position adjacent the first portion to a second position spaced from the first portion; and

a second section extending from the first section, the inner diameter of the second section being constant.

9 . The refrigerator of claim 7 , wherein the at least one rib is located in the second portion.

10 . The refrigerator of claim 6 , wherein the at least one rib includes a plurality of ribs spaced apart from one another in a circumferential direction of the cylinder.