This invention generally relates to a sensor for determining a fluid quality. More particularly, this invention relates to a sensor that can be placed in line along a fluid flow path for determining a quality of a fluid flowing along the path.
Various fluid quality sensors are known. One type of determination made by such sensors is the concentration of one or more components within a fluid mixture. Some example sensors use a capacitor-based measurement technique to make a determination regarding the quality of interest.
One example situation is in automotive fuel systems. It is useful, for example, to determine the alcohol content within a fuel mixture for purposes of adjusting fuel supply parameters in fuel injection systems. A known sensor for making such a determination is shown in U.S. Pat. No. 5,367,264. That document discloses a way of determining the alcohol content of a fuel mixture based on a capacitance and conductance of a capacitor-based measuring circuit, which is exposed to the fuel mixture. A variety of such devices are known.
Another situation where a fluid quality determination is useful is in a catalytic converter arrangement that uses a known selective catalytic reaction to control vehicle engine emissions. In this situation, it is useful to determine a urea concentration level in a fluid supply to the catalytic converter. Such devices utilize a mixture of urea and de-ionized water for producing ammonia hydroxide, which is used to control the nitrogen oxide in exhaust emissions. It is desirable to be able to provide an indication of a urea concentration level so that the catalytic converter will perform as needed or desired.
One shortcoming of previously proposed devices is that they are typically limited to very specific applications. Another limitation is that the placement of such devices is commonly limited to a supply or reservoir tank. There is a need for a more versatile arrangement that can accommodate various situations and that can be more readily incorporated into an appropriate system. This invention addresses those needs.
An example disclosed embodiment of a sensor device for detecting a fluid property includes a first electrode having a fluid passageway extending between ends of the first electrode. At least one of the ends is adapted to be coupled to a fluid conduit. A second electrode is supported within the first electrode fluid passageway and electrically isolated from the first electrode. Fluid in the fluid passageway can fill a space between the first and second electrodes. A housing is supported on the first electrode for housing electronics used to make a determination regarding the fluid property. In one example, the housing is overmolded onto the first electrode.
The example sensor device can be inserted into a fluid supply line, for example. By having the sensor positioned in-line with an appropriate fluid passageway, the sensor is able to provide fluid quality information regarding substantially all of the fluid passing through the passageway. This is an advantage compared to arrangements where a sensor is only exposed to fluid within a limited portion of a supply tank, for example. Additionally, the disclosed sensor arrangement can be readily accommodated into a variety of arrangements and does not require modification of a supply tank, for example.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiments. The drawings that accompany the detailed description can be briefly described as follows.
As can be appreciated from
By coupling the first electrode 24 with the conduits 30 and 32, the fluid passageway 22 accommodates fluid flowing through the conduits 30 and 32 and is in line with the conduits of an appropriate portion of a fluid handling system. In one example, the conduits 30 and 32 are fuel supply lines. In another example, the conduits 30 and 32 are a urea mixture supply for a catalytic converter arrangement.
The sensor device 20 includes a housing portion 40 that is supported on the first electrode 24. In the illustrated example, a container portion 42 supports electronics on a printed circuit board 44. A cover 46 closes off the container portion 42 to protect the electronics on the circuit board 44 from contamination, for example. A support portion 48 is coupled with the container portion 42 and received about at least a portion of the exterior of the first electrode 24.
In the illustrated example, the support portion 48 is overmolded onto the first electrode 24. The entire housing 40 in the illustrated example is molded at one time and secured into position onto the first electrode 24 during the molding process.
A second electrode 50 is supported within the fluid passageway 22 such that fluid flowing through the passageway 22 fills spacing between the inside of the first electrode 24 and the exterior of the second electrode 50. In the example of
The example of
The first electrode 24 and the second electrode 50 operate as a cathode and an anode of a capacitor, respectively. Capacitor-based fluid quality or property measurement techniques are known.
As best appreciated from
In the example of
An electrically conductive member 56 is coupled with the mounting member 52 and appropriate portions of the electronics on the printed circuit board 44 (see
Another feature of the embodiment of
A significant advantage of the example arrangements is that the sensor 20 can be readily incorporated into a fluid supply arrangement and made part of a fuel supply line, for example. In one example, one end of the first electrode 24 is secured to a tank or reservoir while the other end is secured to a conduit that allows fluid to flow into or out of the tank or reservoir.
As can be appreciated from
The example of
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
Number | Name | Date | Kind |
---|---|---|---|
4426616 | Maier | Jan 1984 | A |
4555661 | Benson et al. | Nov 1985 | A |
4915084 | Gonze | Apr 1990 | A |
4945863 | Schmitz et al. | Aug 1990 | A |
4971015 | Gonze | Nov 1990 | A |
5060619 | Sakurai et al. | Oct 1991 | A |
5089703 | Schoen et al. | Feb 1992 | A |
5103184 | Kapsokavathis et al. | Apr 1992 | A |
5119671 | Kopera | Jun 1992 | A |
5134381 | Schmitz et al. | Jul 1992 | A |
5216409 | Ament et al. | Jun 1993 | A |
5230322 | Curran et al. | Jul 1993 | A |
5231358 | Kapsokavathis et al. | Jul 1993 | A |
5255656 | Rader et al. | Oct 1993 | A |
5301542 | Meitzler et al. | Apr 1994 | A |
5361035 | Meitzler et al. | Nov 1994 | A |
5367264 | Brabetz | Nov 1994 | A |
5416425 | Mouaici | May 1995 | A |
5435170 | Voelker et al. | Jul 1995 | A |
5503004 | Agar | Apr 1996 | A |
5594163 | Suzuki | Jan 1997 | A |
5717339 | Murphy et al. | Feb 1998 | A |
5777210 | Voelker et al. | Jul 1998 | A |
5945831 | Sargent et al. | Aug 1999 | A |
6781388 | Wang et al. | Aug 2004 | B1 |
Number | Date | Country |
---|---|---|
199 38 790 | Feb 2001 | DE |
GB 2 210 459 | Jun 1989 | GB |
WO 0227280 | Apr 2002 | WO |