Exhaust gas sensor and method of manufacture
A method of manufacturing an exhaust gas sensor that includes positioning at least a portion of a subassembly of the exhaust gas sensor in a mold fixture, overmolding at least a portion of the subassembly with a ceramic material, and removing the overmolded subassembly from the mold fixture.
1. A method of manufacturing an exhaust gas sensor having a subassembly including a housing, a sensor element, and a weld ring, the method comprising:
positioning at least a portion of the housing and at least a portion of the sensor element in a cavity of a mold fixture;
positioning the weld ring in the mold cavity apart from the housing;
injecting a ceramic material into the mold cavity to overmold at least a portion of the housing and at least a portion of the sensor element, and to mold the ceramic material to the weld ring; and
removing the overmolded subassembly from the mold fixture.
2. The method of claim 1 , wherein injecting the ceramic material at least partially encapsulates the sensor element.
3. The method of claim 2 , wherein the subassembly includes a terminal pin electrically coupled to the sensor element, and the method further comprising coupling a wire to the terminal pin.
4. The method of claim 3 , wherein injecting the ceramic material at least partially encapsulates the terminal pin.
5. The method of claim 1 , wherein injecting the ceramic material results in bonding of the ceramic material to the housing.
6. The method of claim 5 , wherein the housing includes a bore, and wherein injecting results in the ceramic material at least partially filling the bore.
7. The method of claim 1 , further comprising coupling a wire harness sleeve to the weld ring.
8. The method of claim 7 , wherein coupling the wire harness sleeve to the weld ring includes welding the wire harness sleeve to the weld ring.
9. The method of claim 7 , wherein the ceramic material provides an insulating barrier between the housing and the wire harness sleeve.
10. The method of claim 9 , wherein the ceramic material is a mica material.
11. The method of claim 1 , wherein injecting the ceramic material results in bonding of the ceramic material to the sensor element.
12. The method of claim 1 , wherein injecting the ceramic material results in forming a hermetic seal between the ceramic material and the sensor element.
13. The method of claim 1 , wherein injecting the ceramic material results in bonding of the ceramic material to the weld ring.