Ngk Spark Plug Company, Limited

Hideya Inukai

Takayoshi Atsumi

Naoki Yamada

Yoshiyasu Fujii

Takeo Mizui

Yasuhiro Ishiguro

Kouji Ogawa

Ayaka Ota

A sensor including a sensor element, a metallic shell, a terminal fitting, a cylindrical case, lead wires, a connector portion, and a cylindrical heat shield tube. The heat shield tube includes a first tube and a second tube. The second tube is disposed on a distal end side of the first tube and covers an outer surface of the rear end side of the case, while providing an overlapping portion that overlaps the first tube. A rear end side of the first tube is adjacent to the connector portion. A total length T of the heat shield tube and a length S of the overlapping portion satisfy T/10&#x2264;S&#x2264;T/5. Further, a length Lof the first tube and a length Lof the second tube satisfy T/2&#x2264;L&#x3c;L

Sensor

A sensor including a tubular casing having an open rear end; and a first elastic member having a through hole so as to introduce ambient air into the casing and disposed so as to block the rear end opening of the casing. The sensor further includes: a holding inner tube that closely contacts an inner peripheral surface of the through hole; a ventilation filter that has permeability and a waterproofing property, the ventilation filter including a filter blocking portion that blocks a rear end opening of the holding inner tube, and a filter tubular portion connected to the filter blocking portion and surrounding at least a portion of an outer peripheral surface of a rear end portion of the holding inner tube in the peripheral direction; and a holding outer tube that includes a ventilation hole, an outer tube blocking portion covering the filter blocking portion, and an outer tube tubular portion connected to the outer tube blocking portion and surrounding at least a portion of the filter tubular portion in the peripheral direction.

A gas sensor having an axis including a detecting element; a metal shell; an outer cylinder; and a plug member, as defined herein, and the gas sensor includes a first protective member that covers an air vent of the plug member so as to protect the filter member, the protective member having a ventilation portion having an opening smaller than an opening of the air vent and at least partially overlapping the air vent in the axial direction, and at least one of the outer cylinder and the plug member is provided with a locking portion that limits rotation of the protective member around the axis.

Growing community of inventors

Ogaki, Japan

Hideya Inukai