PROBLEM TO BE SOLVED: To provide a liquid injection mechanism having a sealing configuration for reliably sealing between a liquid accelerating member and a liquid holding member. SOLUTION: A liquid holding member for holding a liquid inside, a nozzle for injecting the liquid inside the liquid holding member, and moving the inside of the liquid holding member to give a speed to the liquid to release the liquid from the nozzle. In the liquid injection mechanism including the liquid accelerating member to be injected, the liquid accelerating member covers the shaft portion, the first seal member arranged on the shaft portion, and the outer side of the first seal member, and covers the inner surface of the liquid holding member. It includes a cylindrical member having a sliding contact surface that moves along the surface, and a second seal member that is arranged on the side opposite to the nozzle side with respect to the first seal member. [Selection diagram] Fig. 4【課題】 液体加速部材と液体保持部材との間を確実に密封するシーリング構成を有する液体噴射機構を提供する。【解決手段】 内部に液体を保持する液体保持部材と、該液体保持部材の内部の液体を噴射するノズルと、液体保持部材の前記内部を移動することによって液体に速度を与えてノズルから液体を噴射させる液体加速部材とを含む液体噴射機構において、液体加速部材は、軸部と、軸部に配置された第１シール部材と、第１シール部材の外方を覆い、液体保持部材の内面に沿って移動する摺接面を有する円筒部材と、第１シール部材に対してノズル側とは反対の側に配置された第２シール部材とを備える。【選択図】 図４
