Urea sensor
AssigneeNgk Spark Plug Co., Ltd.
InventorsTakeo Sasanuma, Yoshikuni Sato, Akihiro Yoshida
Life of this patent
Estimating the term…
Abstract
A urea sensor includes a detecting portion which, in use, is immersed in a liquid accommodated in a urea solution tank for detecting the thermal conductivity of the liquid to detect whether the liquid accommodated in the urea solution tank is an aqueous urea solution; and an enclosing member enclosing a periphery of the detecting portion and including one or more vents penetrating the enclosing member. At least one of the vents is a lower vent being of a configuration and size such that a first hypothetical circle having a diameter of not less than 3.5 mm can be wholly contained within the lower vent. At least a portion of the lower vent is positioned below the detecting portion when the urea sensor is positioned for installation in the urea solution tank.
Claims19
A urea sensor comprising:
- a detecting portion, which, in use, is immersed in a liquid accommodated in a urea solution tank, for detecting the thermal conductivity of the liquid so as to detect whether the liquid accommodated in the urea solution tank is an aqueous urea solution;
- and
- an enclosing member enclosing a periphery of the detecting portion and including one or more vents penetrating the enclosing member;
- wherein at least one of the one or more vents comprises a lower vent having a breadth of at least 3.5 mm, said lower vent being disposed such that at least a portion of the lower vent is located closer to a downwardly extending end of the urea sensor than the detecting portion when the urea sensor is positioned for installation in the urea solution tank.
A urea sensor comprising:
- a detecting portion which, in use, is immersed in a liquid accommodated in a urea solution tank, for detecting the thermal conductivity of the liquid so as to detect whether the liquid accommodated in the urea solution tank is an aqueous urea solution;
- and
- an enclosing member enclosing a periphery of the detecting portion and including a plurality of vents penetrating the enclosing member;
- wherein the plurality of vents include a lower vent located closer to a vertically downwardly extending end of the urea sensor than the detecting portion when the urea sensor is positioned for installation in the urea solution tank, and an upper vent located closer to a vertically upwardly extending end of the urea sensor than a lower end of the detecting portion;
- and
- wherein a minimum breadth of the lower vent is greater than a minimum breadth of the upper vent.
A urea sensor comprising:
- a detecting portion, which, in use, is immersed in a liquid accommodated in a urea solution tank, for detecting the thermal conductivity of the liquid so as to detect whether the liquid accommodated in the urea solution tank is an aqueous urea solution;
- and
- an enclosing member enclosing a periphery of the detecting portion and including one or more vents penetrating the enclosing member;
- wherein at least one of the one or more vents comprises a lower vent disposed such that at least a portion of the lower vent is located below the detecting portion when the urea sensor is positioned for installation in the urea solution tank, the lower vent being of a configuration and size such that the lower vent discharges aqueous urea solution from the enclosing member when a liquid having a smaller specific gravity is present in the urea solution tank.
Dependencies are inferred from the claim text.