Locking mechanism for tubular body

A locking mechanism for a tubular body, comprising:

• a tubular housing, the tubular body having an engagement portion and being mounted on at least one end of the tubular housing, and
• a locking member that locks and releases the housing and the tubular body, wherein
• the locking member is mounted to the housing to be able to move in an outer diameter direction by a tapered portion of the tubular body when the tubular body is inserted;
• and
• the housing includes a slit formed to pass a curved portion bent in an inner diameter direction disposed at a leading-end side of the locking member and to lock with the engagement portion of the tubular body mounted on the housing;
• a gap is disposed between the curved portion and an end portion of the slit positioned at a side in an opposite direction to the leading-end side of the locking member, so as not to contact therebetween while at least the locking member is moving, or
• the locking member is mounted to the housing to be able to move in the outer diameter direction, and the housing includes a slit formed to pass the curved portion bent in an inner diameter direction disposed at a leading-end side of the locking member and to lock with the engagement portion of the tubular body mounted on the housing;
• and
• also, the housing includes a guide unit for widening the curved portion toward an outside when the locking member is moved to the outer diameter direction at least at a time the lock is released.