Quick-detachable connecting device with simplified thread structure and connection method using same

A quick-detachable connecting device, comprising:

• a top nozzle;
• a connecting tube sleeve;
• a locking tube;
• and
• a locking piece;
• wherein the top nozzle is penetratedly provided with a connecting tube hole;
• the connecting tube sleeve is provided in the connecting tube hole;
• the locking tube is accommodated in the connecting tube hole;
• an inner circumferential surface of the connecting tube sleeve is provided with a first stopping structure;
• an outer circumferential surface of the locking tube is provided with a second stopping structure;
• the first stopping structure is matched with the second stopping structure to make the locking tube rotationally assembled in the connecting tube sleeve and limit the connecting tube sleeve in an axial direction;
• the locking piece is movably arranged on the locking tube, and is configured to be selectively clamped with the top nozzle to circumferentially limit the locking tube or release the locking tube;
• a top periphery of the locking piece is provided with a stopping lug protruding outward;
• the top nozzle is provided with a limiting groove;
• the limiting groove is located at a top periphery of the connecting tube hole;
• and the stopping lug is configured to be selectively assembled in the limiting groove;
• an inner circumferential surface of the locking tube is provided with a zigzag-shaped groove;
• each side of the zigzag-shaped groove has a plurality of first peak points and a plurality of second peak points;
• a height of the plurality of second peak points is smaller than that of the plurality of first peak points;
• the plurality of first peak points and the plurality of second peak points are alternately distributed;
• an outer circumferential surface of the locking piece is provided with an accommodating ring groove;
• the accommodating ring groove is provided with a locking ball;
• the locking ball is partially accommodated in the zigzag-shaped groove, and is configured to be pressed by the locking piece to roll along the zigzag-shaped groove, so as to achieve switching of the locking ball between the plurality of first peak points and the plurality of second peak points;
• when the locking ball is located at one of the plurality of second peak points, the stopping lug is assembled in the limiting groove;
• and when the locking ball is located at one of the plurality of first peak points, the stopping lug is upwardly disengaged from the limiting groove;
• an elastic piece is provided in the locking tube, and abuts against the locking piece for providing an upward elastic force to the locking piece;
• and
• the inner circumferential surface of the locking tube is also provided with a stopping ring boss;
• the stopping ring boss is located below the zigzag-shaped groove;
• and the elastic piece is arranged on the stopping ring boss, and abuts against a bottom of the locking piece.