Projectile assembly and electric circuit breaker device

An electric circuit breaker device, wherein

• in a housing made of a synthetic resin, an igniter, a projectile made of a synthetic resin, and a conductor piece for forming a part of an electric circuit are disposed in this order from a side of a first end portion of the housing toward a side of a second end portion on a side opposite to the side of the first end portion in a housing axial direction, and an insulated space is closed between the second end portion and the conductor piece,
• a cylinder is disposed in the housing, and the igniter and the projectile are disposed in the cylinder,
• the cylinder includes a first opening on the side of the first end portion of the housing, a second opening on the side of the second end portion of the housing, and a plurality of through holes formed at intervals in a circumferential direction in a peripheral wall portion on a side of the first opening,
• the igniter includes:
• an igniter main body portion provided with an ignition portion and an electro-conductive pin;
• and a resin portion surrounding the igniter main body portion,
• the resin portion closes the first opening and the plurality of through holes of the cylinder and is abutted against an inner wall surface around the through holes of the cylinder,
• both a peripheral wall portion on the side of the first opening and a peripheral wall portion on a side of the second opening of the cylinder are crimped inward to form a first crimped portion and a second crimped portion, and the first crimped portion is abutted against the resin portion of the igniter,
• the conductor piece is a plate piece including a first connection portion and a second connection portion on both end sides and a cut portion at an intermediate portion, and a surface of the cut portion is disposed perpendicularly to the housing axial direction, and
• the projectile is opposed to the cut portion of the conductor piece in the housing axial direction.