Gas generator and gas discharge method

A gas discharge method performed by a gas generator including

• a housing forming an outer shell container and extending from one end side to the other end side,
• an ignition device attached to the housing,
• a combustion chamber formed inside the housing and configured to accommodate a gas generating agent ignited by the ignition device,
• a diffuser portion provided on the other end side of the housing and including a closed end with an end part being closed and a side wall including a plurality of gas discharge ports,
• a filter at least partially accommodated inside the diffuser portion, the filter internally including a hollow flow path directed from a side of the combustion chamber to a side of the closed end, the flow path including a first section including one end connected to the combustion chamber, and a second section connected to the other end of the first section, and
• a block portion configured to bring a closed state between the first section and the second section when a combustion pressure of the gas generating agent during operation is less than a predetermined critical threshold, and bring a communication state between the first section and the second section when the combustion pressure exceeds the critical threshold,
• the side wall of the diffuser portion including a first side wall region positioned around the first section and a second side wall region positioned around the second section, and each of the first side wall region and the second side wall region being provided with one or more of the plurality of gas discharge ports, and
• the gas discharge method comprising:
• supplying an ignition current to ignite the ignition device and combusting the gas generating agent;
• and
• bringing a closed state between the first section and the second section with the block portion when the combustion pressure is less than a predetermined critical threshold, and bringing a communication state between the first section and the second section when the combustion pressure is equal to or greater than the critical threshold.

A gas generator comprising:

• a housing in a tubular shape forming an outer shell container and extending from one end side to the other end side;
• an ignition device attached to the housing;
• a combustion chamber formed inside the housing and configured to accommodate a gas generating agent ignited by the ignition device;
• a diffuser portion in a tubular shape inserted into the one end side of the housing and including a gas discharge port;
• and
• a filter including a body portion accommodated in the diffuser portion and a flange portion protruding in a radial direction outward relative to an inner periphery of the diffuser portion at an end portion of the body portion on the housing side, wherein
• a first annular surface of a surface of the flange portion, the first annular surface facing the body portion side, comes into contact with an end part of the diffuser portion on the housing side.