This invention relates generally to exhaust gas sensors, and more particularly to insulation bushing assemblies for exhaust gas sensors.
Exhaust gas sensors are well known in the automotive industry for sensing the oxygen, carbon monoxide, or hydrocarbon content of the exhaust stream generated by internal combustion engines. Stoichiometric or “Nemst”-type oxygen sensors (a widely used type of exhaust gas sensor) measure the difference between the partial pressure of oxygen found in the exhaust gas and oxygen found in the atmosphere. By determining the amount of oxygen in the exhaust gas, the oxygen sensor enables the engine control unit (“ECU”) to adjust the air/fuel mixture and achieve optimal engine performance. Other types of exhaust gas sensors that operate based on different principles are also known and widely used in the automotive industry.
The present invention provides an improved insulation bushing assembly for an exhaust gas sensor and an improved method of assembling an exhaust gas sensor.
More particularly, the present invention provides, in one aspect, an insulation bushing assembly for use with an exhaust gas sensor. The insulation bushing assembly includes an insulation bushing including a passageway defining a surface. The insulation bushing assembly also includes a contact plate assembly having a contact plate coupled with the insulation bushing and a resilient member extending from the contact plate for insertion into the passageway. The resilient member is engageable with the surface of the passageway during insertion such that the member is deflected by the surface from an undeflected position with respect to the contact plate to a deflected position with respect to the contact plate.
The present invention provides, in another aspect, an exhaust gas sensor including a sensor housing, a sensor element at least partially enclosed within the housing, and an insulation bushing at least partially supported within the housing. The insulation bushing includes a passageway defining a surface. The exhaust gas sensor also includes a contact plate assembly having a contact plate coupled with the insulation bushing and the sensor element. A resilient member extends from the contact plate for insertion into the passageway. The resilient member is engageable with the surface of the passageway during insertion such that the member is deflected by the surface from an undeflected position with respect to the contact plate to a deflected position with respect to the contact plate.
The present invention provides, in yet another aspect, a method of assembling an exhaust gas sensor. The method includes providing an insulation bushing including a passageway defining a surface, providing a contact plate assembly including a contact plate and a resilient member extending from the contact plate, inserting the resilient member into the passageway, engaging the resilient member with the surface, and deflecting the member from an undeflected position with respect to the contact plate to a deflected position with respect to the contact plate.
Other features and aspects of the present invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.
In the drawings, wherein like reference numerals indicate like parts:
a is a partially assembled cross-sectional view of the insulation bushing assembly of
b is a partially assembled, partial cross-sectional view of the insulation bushing assembly of
a is an assembled cross-sectional view of the insulation bushing assembly of
b is an assembled, partial cross-sectional view of the insulation bushing assembly of
a is a perspective view of an insulation bushing from the insulation bushing assembly of
b is a perspective view of another construction of the insulation bushing of
c is a perspective view of yet another construction of the insulation bushing of
a is a partially assembled cross-sectional view of the insulation bushing assembly of
b is a partially assembled, partial cross-sectional view of the insulation bushing assembly of
a is an assembled cross-sectional view of the insulation bushing assembly of
b is an assembled, partial cross-sectional view of the insulation bushing assembly of
a is a partially assembled cross-sectional view of the insulation bushing assembly of
b is a partially assembled, partial cross-sectional view of the insulation bushing assembly of
a is an assembled cross-sectional view of the insulation bushing assembly of
b is an assembled, partial cross-sectional view of the insulation bushing assembly of
Before any features of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including”, “having”, and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The use of letters to identify elements of a method or process is simply for identification and is not meant to indicate that the elements should be performed in a particular order.
The sensor 10 includes a generally cylindrical metallic housing 14 threadably engaged with a threaded aperture of an exhaust pipe (not shown) or other component of an internal combustion engine (also not shown) used for automotive applications or non-automotive applications, such as motorcycles, snowmobiles, ATV's, lawnmowers, and the like.
The housing 14 receives and supports a sensor element 46 including an outer or exhaust electrode communicating with the exhaust gas stream, and an inner or reference electrode communicating with reference air, as understood by those skilled in the art. A seal ring 18 is positioned between the sensor element 46 and the housing 14 to seal the sensor element 46 to the housing 14. Reference is made to U.S. patent application Ser. No. 10/610,479 filed on Jun. 30, 2003, now U.S. Pat. No. 6,843,105, the entire contents of which are incorporated herein by reference, for discussion of additional features of the housing 14 and the sensor element 46 not described herein.
The sensor 10 further includes a sleeve 94 connected to the housing 14. An insulation bushing 114 is disposed within the sleeve 94 and includes a first end 118 received in the housing 14 and a second end 122 at least partially extending out of the sleeve 94. A disk spring 130 is disposed between the sleeve 94 and the bushing 114 to bias the bushing 114 toward the housing 14. In the illustrated construction, the bushing 114 is made of ceramic materials known as soapstone steatite or crypto-crystalline talc, and in some instances, can be made from materials having lower thermal conductivity and higher compressive strength, such as DOTHERM DT600M available from Industria Engineering Products in Uxbridge, United Kingdom.
With continued reference to
The contact plate assemblies 138a, 138b are made from an electrically conducive material, such as metal. The bushing 114 thereby electrically isolates the contact plate assemblies 138a, 138b from the housing 14 and the sleeve 94. Additionally, the internal passageways 134a, 134b electrically isolate the signal contact plate assembly 138a from the ground contact plate assembly 138b.
With reference to
With reference to the internal passageway 134a shown in
With continued reference to
The exit portion 162 of the internal passageway 134a includes a third surface 178a spaced from the second surface 170a and a fourth surface 182a opposite the third surface 178a. Like the second surface 170a, the third and fourth surfaces 178a, 182a are substantially parallel with the longitudinal axis 174 of the bushing 114.
As shown in
With reference to the signal contact plate assembly 138a shown in
With reference to
With reference to
During assembly of the insulation bushing assembly 142 (see
With reference to
More particularly, with exemplary reference to the compression tab 198a (with the same discussion applying to the compression tab 198b and the internal passageway 134b), the compression tab 198a assumes an undeflected position upon initial insertion into the entry portion 154 of the internal passageway 134a. With continued insertion into the internal passageway 134a, the compression tab 198a encounters the ramp surface 166a in the passageway 134a that causes the compression tab 198a to deflect toward the contact wire 190a. The ramp surface 166a, in other words, causes the compression tab 198a to move from an initial undeflected position to a deflected position upon continued insertion into the passageway 134a.
Since the compression tab 198a is resilient, the tab 198a applies a force to the ramp surface 166a as it is deflected. The ramp surface 166a therefore applies a reaction force, or a normal force, to the compression tab 198a to balance the force applied by the compression tab 198a. Such a normal force includes a component that is transverse to the longitudinal axis 174, which results in a frictional force developed between the compression tab 198a and the ramp surface 166a, and a component that is parallel to the longitudinal axis 174, which tends to urge the contact plate 186a away from the first end 118 of the bushing 114.
For the compression tab 198a to deflect upon engaging the ramp surface 166a, the contact plate 186a should be maintained in a substantially fixed orientation with respect to the insulation bushing 114 (i.e., the contact plate 186a should be kept substantially parallel with the first end 118 of the insulation bushing 114) during insertion of the contact plate assembly 138a into the internal passageway 134a. As shown in
With reference to
Such a normal force allows a frictional force to develop between the compression tab 198a and the second surface 170a. The frictional force is sufficient to maintain the contact plate assembly 138a engaged with the internal passageway 134a when, for example, the bushing 114 is oriented substantially vertically with the engaged contact plate 186a at the lower end. Even in this orientation, the weight of the contact plate assembly 138a by itself is not sufficient to cause the contact plate assembly 138a to fall out of the internal passageway 134a. This facilitates handling, manipulation, and further assembly of the assembled bushing 114 and contact plate assemblies 138a, 138b.
Alternatively, locking structure (e.g., a detent configuration) may be incorporated on one or more of the internal passageways 134a, 134b and the compression tabs 198a, 198b, such that the contact plate assemblies 138a, 138b may be retained in the bushing 114. However, such locking structure may not result in the contact plate assemblies 138a, 138b being releasable from the bushing 114 if later desired.
With continued reference to
With reference to
The contact plate assemblies 210a, 210b include respective contact plates 222a, 222b and respective contact wires 226a, 226b mechanically coupled to the contact plates 222a, 222b in a similar fashion as the contact wires 190a, 190b and the contact plates 186a, 186b of the sensor 10 of
However, the contact wires 226a, 226b have a different configuration than the contact wires 190a, 190b of the sensor 10 of
With reference to
More particularly, with exemplary reference to the contact wire 226a (with the same discussion applying to the contact wire 226b and the internal passageway 214b), the contact wire 226a assumes an undeflected position upon initial insertion into the entry portion 154 of the internal passageway 214a (see
Since the contact wire 226a is resilient, the wire 226a applies a force to the ramp surface 166a as it is deflected. The ramp surface 166a therefore applies a reaction force, or a normal force, to the contact wire 226a to balance the force applied by the contact wire 226a. Such a normal force includes a component that is transverse to the longitudinal axis 174, which results in a frictional force developed between the contact wire 226a and the ramp surface 166a, and a component that is parallel to the longitudinal axis 174, which tends to urge the contact plate 222a away from the first end 220 of the bushing 218.
With reference to
Such a frictional force is sufficient to maintain the contact plate assembly 210a engaged with the internal passageway 214a when, for example, the bushing 218 is oriented substantially vertically with the engaged contact plate 222a at the lower end. Even in this orientation, the weight of the contact plate assembly 210a by itself is not sufficient to cause the contact plate assembly 210a to fall out of the internal passageway 214a. This facilitates handling, manipulation, and further assembly of the assembled bushing 218 and contact plate assemblies 210a, 210b.
With continued reference to
The contact plate assemblies 254a, 254b include respective contact plates 262a, 262b and respective contact wires 266a, 266b mechanically coupled to the contact plates 262a, 262b in a similar fashion as the contact wires 190a, 190b and the contact plates 186a, 186b of the sensor 10 of
However, the contact wires 266a, 266b have a different configuration than the contact wires 190a, 190b of the sensor 10 of
With reference to
More particularly, with exemplary reference to the compression tab 274a (with the same discussion applying to the compression tab 274b and the internal passageway 134b), the compression tab 274a assumes an undeflected position upon initial insertion into the entry portion 154 of the internal passageway 134a. With continued insertion into the internal passageway 134a, the compression tab 274a encounters the ramp surface 166a to cause the compression tab 274a to deflect radially outwardly to a deflected position.
With reference to
Such a frictional force is sufficient to maintain the contact plate assembly 254a engaged with the internal passageway 134a when, for example, the bushing 114 is oriented substantially vertically with the engaged contact plate 262a at the lower end. Even in this orientation, the weight of the contact plate assembly 254a by itself is not sufficient to cause the contact plate assembly 254a to fall out of the internal passageway 134a. This facilitates handling, manipulation, and further assembly of the assembled bushing 114 and contact plate assembly 254a.
With continued reference to
The insulation bushing assemblies 142, 206, 250 of
Various features of the invention are set forth in the following claims.
Number | Name | Date | Kind |
---|---|---|---|
2879583 | Booth et al. | Mar 1959 | A |
3007810 | Hobrock | Nov 1961 | A |
3574033 | Kolkman et al. | Apr 1971 | A |
3916071 | Kinnebrew et al. | Oct 1975 | A |
4001758 | Esper et al. | Jan 1977 | A |
4107018 | Bode et al. | Aug 1978 | A |
4127424 | Ullery, Jr. | Nov 1978 | A |
4130797 | Hattori et al. | Dec 1978 | A |
4133910 | Ruwe et al. | Jan 1979 | A |
4155827 | Maurer et al. | May 1979 | A |
4212720 | Maurer et al. | Jul 1980 | A |
4264647 | Trevorrow | Apr 1981 | A |
4296148 | Friese | Oct 1981 | A |
4305803 | Beyer et al. | Dec 1981 | A |
4310401 | Stahl | Jan 1982 | A |
4338362 | Turcotte | Jul 1982 | A |
4339320 | Friese et al. | Jul 1982 | A |
4413502 | Ohta et al. | Nov 1983 | A |
4419212 | Dietz et al. | Dec 1983 | A |
4490411 | Feder | Dec 1984 | A |
4504522 | Kaiser et al. | Mar 1985 | A |
4540479 | Sakurai et al. | Sep 1985 | A |
4556475 | Bayha et al. | Dec 1985 | A |
4595614 | Nunlist | Jun 1986 | A |
4597850 | Takahasi et al. | Jul 1986 | A |
4693538 | Matsuo | Sep 1987 | A |
4701348 | Neville | Oct 1987 | A |
4773376 | Uchikawa et al. | Sep 1988 | A |
4806455 | LaBianca | Feb 1989 | A |
4930700 | McKown | Jun 1990 | A |
4943330 | Iino et al. | Jul 1990 | A |
5017340 | Pribat et al. | May 1991 | A |
5032568 | Lau et al. | Jul 1991 | A |
5096734 | Nikulainen et al. | Mar 1992 | A |
5104042 | McKown | Apr 1992 | A |
5116263 | Bennett et al. | May 1992 | A |
5139639 | Holleboom | Aug 1992 | A |
5169513 | Mase et al. | Dec 1992 | A |
5190482 | VanDerStuyf et al. | Mar 1993 | A |
5316503 | Thompson et al. | May 1994 | A |
5328728 | Swirbel et al. | Jul 1994 | A |
5329806 | McClanahan et al. | Jul 1994 | A |
5346605 | Wolcott et al. | Sep 1994 | A |
5372775 | Hayashi et al. | Dec 1994 | A |
5423972 | Mann et al. | Jun 1995 | A |
5522979 | Tatumoto et al. | Jun 1996 | A |
5546787 | Hafele et al. | Aug 1996 | A |
5573650 | Fukaya et al. | Nov 1996 | A |
5626499 | Yagi et al. | May 1997 | A |
5670032 | Friese et al. | Sep 1997 | A |
5711863 | Henkelmann et al. | Jan 1998 | A |
5736095 | Shimada et al. | Apr 1998 | A |
5739414 | Paulus et al. | Apr 1998 | A |
5780100 | McCabe et al. | Jul 1998 | A |
5804050 | Hayakawa et al. | Sep 1998 | A |
5817920 | Kuisell et al. | Oct 1998 | A |
5846391 | Friese et al. | Dec 1998 | A |
5886248 | Paulus et al. | Mar 1999 | A |
5900129 | Tsuji et al. | May 1999 | A |
5922938 | Hafele | Jul 1999 | A |
5935399 | Tanaka et al. | Aug 1999 | A |
5942092 | Weyl et al. | Aug 1999 | A |
5948225 | Katafuchi et al. | Sep 1999 | A |
5955656 | Graser et al. | Sep 1999 | A |
6063249 | Duce et al. | May 2000 | A |
6068524 | Koumatsu | May 2000 | A |
6068746 | Kojima et al. | May 2000 | A |
6074694 | Friese et al. | Jun 2000 | A |
6082175 | Yoshikawa et al. | Jul 2000 | A |
6096372 | Nomura et al. | Aug 2000 | A |
6164120 | Friese et al. | Dec 2000 | A |
6206377 | Weyl | Mar 2001 | B1 |
6246000 | Wehrmann et al. | Jun 2001 | B1 |
6266997 | Nelson | Jul 2001 | B1 |
6273432 | Weyl et al. | Aug 2001 | B1 |
6319376 | Graser et al. | Nov 2001 | B1 |
6342141 | Nelson | Jan 2002 | B1 |
6408680 | Friese et al. | Jun 2002 | B2 |
6486605 | Beunas et al. | Nov 2002 | B1 |
6527573 | Maga et al. | Mar 2003 | B2 |
6589612 | Cintra et al. | Jul 2003 | B1 |
20030074950 | Yamada et al. | Apr 2003 | A1 |
Number | Date | Country |
---|---|---|
10225896 | Aug 2004 | DE |
1391724 | Feb 2004 | EP |
WO 0134951 | May 2001 | WO |
Number | Date | Country | |
---|---|---|---|
20050224347 A1 | Oct 2005 | US |