Tuning freedom degree improvement type bush and suspension system

A bush, comprising:

• a second inner pipe forming a central protrusion in a central section of the second inner pipe;
• an outer pipe forming a third protrusion at a first inner side and a fourth protrusion at a second inner side, wherein the third and fourth protrusions are arranged outside of the central protrusion;
• and
• a rubber part provided between the second inner pipe and the outer pipe,
• wherein the outer pipe includes:
• an end protrusion flange to form a locking fixing force for a front end mass of the rubber part, and
• an end bending flange to form an adhesive fixing force for a rear end mass of the rubber part,
• wherein the second inner pipe forms:
• a first protrusion at a position corresponding to the third protrusion, and a second protrusion at a position corresponding to the fourth protrusion,
• wherein the central protrusion, the first protrusion and the second protrusion are connected to each other forming a wave-shaped body of the second inner pipe and each comprise at least one of a flat upper surface or a flat lower surface such that a radius length of the central protrusion, the first protrusion and the second protrusion is greater than a width length thereof.