PROBLEM TO BE SOLVED: To provide a liquid mixture injection apparatus having a rubber plug which keeps a slit in a closed condition even when liquid pressure within a chamber section is increased while the slit of the rubber plug is closed.SOLUTION: A liquid mixture injection unit 10 of the liquid mixture injection apparatus A includes the chamber section 11, a downstream branch pipe 12, a connecting opening 13 and an upstream branch pipe 14 which are extending in different directions from the chamber section 11, and a cap member 20 attached to the connecting opening 13b. The rubber plug 25 having the slit 25a is attached within the cap member 20. The inner circumferential surface of the cap member 20 has the inner circumferential face 21b tapered gradually from the lower side to the upper side, and a part of the rubber plug 25 that comes into close contact with the inner circumferential face 21b is tapered gradually from the lower side to the upper side. In addition, the inclination angle of the outer circumferential surface of the rubber plug 25 is larger than that of the inner circumferential face 21b.COPYRIGHT: (C)2008,JPO&INPIT【課題】 ゴム栓のスリットを閉塞した状態でチャンバー部内の液圧を大きくしてもスリットの閉塞状態を維持できるゴム栓を備えた液体混注具を提供すること。【解決手段】 液体混注具Aの混注具本体10を、チャンバー部11と、チャンバー部11からそれぞれ異なる方向に延びる下流分岐管12、連結用開口部13、上流分岐管14および連結用開口部13bに取り付けられた蓋部材20とで構成した。そして、蓋部材20内に、スリット25aが設けられたゴム栓25を取り付けた。また、蓋部材20の内周面に、下部側から上部側に向かって徐々に細くなった内周面21bを形成し、ゴム栓25における内周面21bに密接する部分を下部側から上部側に向かって徐々に細くなるように形成した。さらに、ゴム栓25の外周面の傾斜角度を、内周面21bの傾斜角度よりも大きくした。【選択図】 図4
