GAS GENERATOR

To provide a gas generator which can improve ignition performance and combustion performance of a gas generating agent within a combustion chamber.SOLUTION: A gas generator includes: an outer shell container which has a combustion chamber for storing a first gas generating agent therein; an igniter; an inner cylinder member which is arranged to surround the igniter and has a storage chamber formed inside to store a second gas generating agent; one or a plurality of communication holes provided in the inner cylinder member; and a closing cover section which covers at least a part of an outer peripheral surface of the inner cylinder member so as to close one or a plurality of communication holes. The closing cover section forms a gap between the closing cover section and the inner cylinder member by pressure from the storage chamber during an operation of the igniter, so that one or a plurality of communication holes are opened and a ventilation passage from the communication holes to a lower end of the closing cover section is formed. At least a part of one or a plurality of communication holes is provided in an upper side coated region on an upper side of an axial direction center position of the inner cylinder member, of regions where the inner cylinder member is covered with the closing cover section before the operation of the igniter.SELECTED DRAWING: Figure 10 【課題】燃焼室内のガス発生剤の着火性能及び燃焼性能を向上させることのできるガス発生器を提供する。【解決手段】ガス発生器は、第１ガス発生剤を収容した燃焼室を内部に有する外殻容器と、点火器と、点火器を囲むように配置されて内側に第２ガス発生剤を収容する収容室が形成された内筒部材と、内筒部材に設けられた１又は複数の連通孔と、１又は複数の連通孔を閉塞するように内筒部材の外周面の少なくとも一部を覆う閉塞カバー部を備え、閉塞カバー部は、点火器の作動時に収容室からの圧力によって内筒部材との間に隙間を形成することで１又は複数の連通孔を開放すると共に連通孔から閉塞カバー部の下端に至る通気路を形成する。点火器の作動前に内筒部材が閉塞カバー部に覆われている領域のうち、内筒部材の軸方向中央位置よりも上側の上側被覆領域に１又は複数の連通孔の少なくとも一部が設けられている。【選択図】図１０