Cover and sensor for diesel exhaust fluid (def) module

Abstract

A cover for a DEF assembly with openings dimensioned to receive various components that are positioned in the DEF holding tank and associated seals for closing the openings and retaining the components is disclosed. The seals are fixed to the cover by a sonic weld.

What is claimed is: 
     
         1 . A sensor assembly for a DEF module, the sensor assembly comprising:
 a sensor housing having a first end that includes a shoulder with an upstanding collar, a second end, and a hollow interior;   a junction housing having a first end with a sleeve that engages the upstanding collar of the sensor housing, and a second end with an opening; and,   a sensor element arranged in a lower portion of the hollow interior.   
     
     
         2 . The sensor assembly according to  claim 1 , wherein the first end of the junction housing is sonic welded to the upstanding collar of the sensor housing. 
     
     
         3 . The sensor assembly according to  claim 2 , further comprising a potting compound that fills the hollow interior and surrounds the sensor element. 
     
     
         4 . The sensor assembly according to  claim 3 , wherein the potting compound at least partially fills a portion of the junction housing. 
     
     
         5 . The sensor assembly according to  claim 1 , wherein the second end of the housing is closed by a base cap. 
     
     
         6 . The sensor assembly according to  claim 5 , wherein the base cap is sonic welded to the sensor housing. 
     
     
         7 . The sensor assembly according to  claim 1 , further comprising a sealing cap that closes the opening in the second end of the junction housing. 
     
     
         8 . The sensor assembly according to  claim 7 , wherein the sealing cap is sonic welded to the junction housing. 
     
     
         9 . The sensor assembly according to  claim 1 , wherein the sensor detects temperature and fill level of diesel exhaust fluid in a tank. 
     
     
         10 . The sensor assembly according to  claim 1 , wherein the sensor is a temperature sensor. 
     
     
         11 . A cover assembly for a diesel exhaust fluid module, the cover assembly comprising:
 a cover, configured to define a top portion of the diesel exhaust fluid tank, includes at least one opening, dimensioned for passage of a lead between an exterior element and an interior of the tank, and a collar;   a plug, configured to be press-fit into the at least one opening, include a passageway dimensioned for the lead to extend therethrough; and   a sealing cap that engages an outer surface of the collar, and is sealed to the cover.   
     
     
         12 . The cover assembly according to  claim 11 , wherein the at least one opening has a first tapered annular surface. 
     
     
         13 . The cover assembly according to  claim 12 , wherein the plug is formed from a compressible material, whereby the at least one passageway is constricted around the lead when the plug is press-fit into the at least one opening. 
     
     
         14 . The cover assembly according to  claim 13 , wherein the plug is formed from plastic. 
     
     
         15 . The cover assembly according to  claim 11 , wherein the sealing cap is sonic welded to the cover. 
     
     
         16 . The cover assembly according to  claim 11 , wherein the plug engages directly with an annular surface of the at least one opening in the cover. 
     
     
         17 . The cover assembly according to  claim 11 , wherein the radially extending portion of the sealing cap is configured to extend radially over an interface between the collar and the plug. 
     
     
         18 . The cover assembly according to  claim 11 , wherein the cover has a second opening with a barbed fitting for connecting a pickup tube hose that extends into the tank. 
     
     
         19 . A method of making a sensor assembly for a diesel exhaust fluid module comprising:
 providing a sensor housing having a hollow opening that extends through a first end that includes a shoulder with an upstanding collar, and a second end;   providing a junction housing having a first end with a sleeve dimensioned to surround and engage the upstanding collar of the sensor housing, and a second end defining an opening for passage of at least one electrical wire;   providing a sensor element connected to the at least one electrical wire and arranged in a lower portion of the hollow opening;   telescoping the sleeve of the junction housing over the upstanding collar of the sensor housing; and   securing the first end of the junction to the upstanding collar of the sensor housing.   
     
     
         20 . The method of  claim 19 , wherein securing the first end of the junction to the upstanding collar of the sensor housing includes sonic welding. 
     
     
         21 . A cover assembly for a diesel exhaust fluid tank, the cover assembly comprising:
 a cover configured to define a top portion of the diesel exhaust fluid module includes an axially extending collar that defines at least one opening dimensioned to allow passage of an electrical wire into a diesel exhaust fluid tank;   a plug that has at least one passage dimensioned to allow the electrical wire to extend into the Def tank and is configured for a press-fit into the at least one opening;   a sealing cap that has: a first portion configured to engage an axially outer surface of the collar, a second portion that extends inward from the axially extending portion of the collar, and, is fastened to the cover.   
     
     
         22 . A sensor assembly for a diesel exhaust fluid tank, the sensor assembly comprising:
 a sensor housing with a central opening that extends between a diesel exhaust fluid tank's base and an open end with a surrounding shoulder;   the surrounding shoulder supports an upstanding open collar;   a junction housing has a first end that is mated with the upstanding open collar and a second end configured for passage of an electrical conductor associated with a sensor;   a cap having a portion that encloses a gasket in abutment with the second end of the housing and a portion that engages with the second end of the housing;   the cap and gasket have through passages that enable an electrical conductor associated with a sensor to extend beyond the cap;   a sensor is arranged in a lower portion of the central opening with at least one electrical conductor that extends beyond the cap; and,   a thermally conductive potting compound surrounds the at least one electrical conductor between the sensor and the cap.   
     
     
         23 . A diesel exhaust fluid tank cover and sensor assembly comprising:
 a cover configured for closing a diesel exhaust fluid tank;   a sensor housing configured to receive a sensor between an open first end and a second end closed by a first sealing cap;   a sensor positioned in a lower portion of the sensor housing toward the second end with at least one electrical lead that passes through the open first end; and,   a plug, through which the at least one electrical lead passes, is positioned within an opening in the cover and secured to the cover by a second sealing cap;   wherein the second sealing cap is sonic welded to the cover.   
     
     
         24 . The assembly of  claim 23 , wherein the first sealing cap is sonic welded to the sensor housing. 
     
     
         25 . The assembly of  claim 23 , wherein the first sealing cap is sonic welded to the sensor housing and the second sealing cap is sonic welded to the cover. 
     
     
         26 . The assembly of  claim 23 , wherein the at least one electrical lead is encased in potting compound.