Denso Corporation

Nippondenso Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Michihiro Yamakawa

Isao Watanabe

Masanori Fukutani

Toshihiro Sakawa

Minoru Ohta

Nobuyuki Tsuji

Jiro Nakano

Takao Akatsuka

Takao Ishibashi

Masao Kawaguchi

Taiji Yokoyama

A heater is inserted into an inside chamber of a sensor element until a tip end of the heater is surely brought into contact with a bottom surface of the inside chamber. Next, a metallic holder is attached on an outside surface of the heater. Then, the metallic holder is slid along the outside surface of the heater toward the bottom surface of the sensor element to engage the metallic holder with an edge of the sensor element.

Heater-equipped air-fuel ratio sensor

Air fuel ratio sensor

Assembling method for a heater-equipped air-fuel ratio sensor

An oxygen concentration detector easily assembled without producing conducting malfunctions at an external electrode includes a cylindrical housing and a detecting element being inserted into and disposed inside the housing. Powdery seal materials made of ceramic power are filled under pressure between a top portion of the detecting element and the housing. The detecting element has the external electrode at an external surface thereof and a lead portion extending upwardly from the external electrode. A ring-shaped conducting member is installed between the lead portion of the detecting element and the housing as a ground to conduct electricity therebetween and has a resilient contacting piece in contact with the lead portion at an inner peripheral portion of the ring-shaped conducting member.

Oxygen concentration detector

Air fuel ratio sensor for use in an exhaust gas purification system for an internal combustion engine. The sensor has an outer and inner cover 12 and 13 for protection of lead wires 16, 18 and 19 to a detecting element 3 and a heater 5 of the sensor, a rubber seal for 2 for obtaining a sealing between the covers and the lead wires and a water repellent filter 36 for obtaining a seal between the inner and outer covers 12 and 13, while keeping an air ventilation capability of the space inside the covers. For receiving the lead wires 16, 18 and 19, the seal 2 is formed with holes 20such that the minimum thickness between the holes and the minimum thickness between the hole and an outer surface of the seal is 1 mm or more. A crimping of the outer cover 12 is done so that a deformation of the seal 2 in a range between 10 to 20% of the outer diameter is obtained. A crimping of the outer cover 12 is further done at a first section 12A at a larger force for fixation of the outer cover 12 to the inner cover 12 and at a second section 12B at a smaller force for holding the water repellent filter 36 between the outer and inner covers. In the crimping, the crimping at the first section is completed simultaneously or earlier from the completion of the crimping at the second section.

Air fuel ratio sensor and method for assembling the same

An oxygen sensor according to the present invention comprises a tumbler-shaped solid electrolytic element formed of an oxygen-ion-conductive metal oxide. A first electrode and a lead electrically connected thereto are formed on the outer peripheral surface of the element which is exposed to exhaust gas. A second electrode is fixed to the inner peripheral surface of the element which is exposed to the atmosphere. The element is held by a ring-shaped metallic holder. The holder and the first electrode are electrically insulated from each other. A conductive metallic pipe member is disposed between the element and the holder. One end of the pipe member is electrically connected to the lead by means of a conductive metal ring. A partition wall extends integrally from one end of the pipe member, defining between its inner surface and the other peripheral surface of the element a space for housing the conductive metal ring between the pipe member and the lead. A seal member is interposed between the outer peripheral surfaces of the pipe member and the partition wall and the inner peripheral surface of the holder. The seal member is formed by compacting a powdered electrial insulating material.

Oxygen sensor

Growing community of inventors

Kariya, Japan

Michihiro Yamakawa