Gas sensor

A gas sensor comprising:

• a sensor element which includes a detection unit which is capable of detecting a gas at a position on a distal end side in an axial direction thereof;
• a cylindrical housing in which the sensor element is disposed in a state where the detection unit projects on a distal end side in the axial direction;
• a contact terminal which is in contact with a terminal portion provided at a position on a base end side in the axial direction of the sensor element;
• an insulator holding the contact terminal;
• a lead wire connected to the contact terminal and drawn outside;
• a sealing member holding the lead wire;
• an inner periphery side cover mounted on an outer periphery of the housing at a position on the base end side in the axial direction;
• and
• an outer periphery side cover disposed on an outer periphery side of the inner periphery side cover, forming a substantially cylindrical space with the inner periphery side cover, and holding the sealing member on an inner periphery side, wherein
• a distal end portion in the axial direction of the inner periphery side cover is mounted on an outer periphery of the housing at a position on the base end side in the axial direction by bonding, press fitting or swaging,
• an end portion on the distal end side in the axial direction of the substantially cylindrical space is closed by an entire circumference of a distal end portion in the axial direction of the outer periphery side cover being mounted on an entire circumference of a distal end portion in the axial direction of the inner periphery side cover by bonding, press fitting or swaging,
• the substantially cylindrical space is formed by an outer diameter of the inner periphery side cover being smaller at the distal end portion in the axial direction than at a portion located on the base end side of the distal end portion, and
• an opening on the base end side in the axial direction of the substantially cylindrical space is open by a proximal portion in the axial direction of the inner periphery side cover being disposed on an inner periphery side of the outer periphery side cover,
• a bent portion which is bent on the inner periphery side with respect to a cylindrical body portion of the inner periphery side cover is formed at a proximal portion in the axial direction of the inner periphery side cover, a swage member being disposed between the bent portion and an end surface on the base end side in the axial direction of the insulator, and
• the insulator is accommodated in the cylindrical body portion of the inner periphery side cover.