Female coupler connection structure

A female coupler connection structure comprising:

• a main body, being internally provided with a plugging passage axially extending therethrough and having an engagement section located at a front end thereof;
• the engagement section having two tangential slots on diametrically opposite sides of a peripheral wall of the engagement section, and the tangential slots respectively defining a through opening communicable with the plugging passage;
• a retaining module, being provided around an outer side of the engagement section and having at least a portion thereof being fitted in the tangential slots;
• the retaining module including at least one pin member pivotally mounted on the retaining module adjacent to the tangential slots, the pin member having an actuation portion passing the through opening into the plugging passage;
• a spring, being fitted on around the engagement section and having an end pressed against a rear end of the retaining module and another end pressed against an annular locating groove formed on around the engagement section;
• and
• a pulling cover, being assembled to an outer side of the spring and the retaining module with a front end of the retaining module pressed against the pulling cover.