Member linking mechanism and member linking method

A member linking mechanism comprising:

• a first member including a member linking part which is in a cylindrical shape and has an opening on a distal-end surface thereof, and a stepped part on an outer peripheral surface or inner peripheral surface of the member linking part, the stepped part being inclined from a distal end to a base end of the member linking part in a circumferential direction;
• a second member to be linked to the member linking part;
• an elastic sealing member sandwiched between the first member and the second member so as to seal the opening of the distal-end surface of the member linking part;
• and
• a linking member having a linking member body having a lever configured to hold an end part, of the second member, adjacent to the first member, and an elastic deformation part provided to the linking member body, the linking member being configured to link the first and second members together by pressing, with an elastic force of the elastic deformation part, the first and second members in a direction in which the first and second members come close to each other, wherein
• the elastic deformation part of the linking member has a protrusion part that protrudes toward the outer or inner peripheral surface of the member linking part so as to engage with the stepped part of the member linking part,
• due to a rotation of the linking member in a circumferential direction of the member linking part, the elastic deformation part is elastically deformed such that the protrusion part is slid along the stepped part, and generates an elastic force that deforms the elastic sealing member as required when the protrusion part reaches a position at a predetermined distance from the base end of the member linking part, and
• one of the protrusion part or a sliding surface of the stepped part is made of a high-hardness material having a high hardness, while the other is made of a resin having a lower hardness than the high-hardness material and high sliding properties with respect to the high-hardness material.