Capacitive sensor assembly with soot build-up inhibiting coating

• US 5,907,278 A
• Filed: 04/16/1998
• Issued: 05/25/1999
• Est. Priority Date: 12/17/1996
• Status: Expired due to Fees

• Current Assignee: Kavlico Corporation (Sensata Technologies Holding Plc)
• Original Assignee: Kavlico Corporation (Sensata Technologies Holding Plc)
• Inventors: Nguyen, Nhan, Park, Kyong M., Nassar, Marcos A.
• Primary Examiner(s): Wu, Daniel J.
• Application Number:
  US09/061,635
• Time in Patent Office: 404 Days
• Field of Search: 340/438, 340/439, 340/440, 340/449, 340/450, 340/450.3, 340/459, 340/461, 340/618, 340/689, 340/693.5, 73/304 C, 73/53.05, 324/658, 324/698, 324/686, 324/663, 123/196 R, 123/196 M, 123/196 S, 123/198 D, 33/366
• US Class Current: 340/450.3
• CPC Class Codes: G01C 9/20 the indication being based on the inclination of the surface of a liquid relative to its container
• CPC Class Codes: G01F 23/263 by measuring variations in capacitance of capacitors
• CPC Class Codes: G01F 23/804 containing circuits handling parameters other than liquid level
• CPC Class Codes: G01N 27/221 by investigating the dielectric properties using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26
• CPC Class Codes: G01N 27/226 Construction of measuring vessels; Electrodes therefor
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

A sensor assembly for measuring characteristics of motor oil in a vehicle includes a housing adapted to be mechanically coupled to a vehicle for receiving motor oil of the vehicle and at least one capacitive sensor including sensing electrodes positioned relative to the housing to measure characteristics of motor oil between the sensing electrodes. The sensing electrodes are coated with a soot build-up inhibiting coating which, in a preferred embodiment, is a silicone coating. The at least one capacitive sensor include an oil level sensor and an oil deterioration sensor in a preferred embodiment.

Claims

1. A sensor assembly for measuring characteristics of motor oil in a vehicle, the sensor assembly comprising:

a housing mechanically coupled to a vehicle in a substantially fixed orientation relative to the vehicle, said housing including a chamber for receiving motor oil of the vehicle, said chamber being formed and positioned relative to other components of the vehicle such that a volume of the motor oil proportionally related to a total volume of motor oil in the vehicle is provided to the chamber; and

a plurality of capacitive sensors positioned within said housing, each of said capacitive sensors including a plurality of sensing electrodes, said capacitive sensors being adapted to measure a plurality of characteristics of the motor oil between said sensing electrodes, each of said sensing electrodes being covered by a silicone coating.

2. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 1 wherein said plurality of capacitive sensors comprise an oil level sensor.

3. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 2 wherein said plurality of capacitive sensors further comprise an oil deterioration sensor.

4. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 2 wherein said oil level sensor and another of said plurality of capacitive sensors share a common electrode.

5. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 1 wherein said plurality of capacitive sensors comprise an oil deterioration sensor.

6. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 5 wherein said plurality of capacitive sensors further comprise an oil level sensor.

7. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 5 wherein said oil deterioration sensor and another of said plurality of capacitive sensors share a common electrode.

8. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 1 further comprising:

a tilt sensor mechanically coupled to said housing in a substantially fixed orientation relative to the vehicle, said tilt sensor providing an output signal indicative of an orientation of said tilt sensor relative to a vector representing forces applied to said tilt sensor.

9. A sensor assembly for measuring characteristics of motor oil in a vehicle, the sensor assembly comprising:

a housing mechanically coupled to a vehicle in a substantially fixed orientation relative to the vehicle, said housing being formed and positioned relative to other components of the vehicle to receive a volume of motor oil proportionally related to a total volume of motor oil in the vehicle; and

at least one capacitive sensor mechanically coupled to said housing, said at least one capacitive sensor including a plurality of sensing electrodes, said at least one capacitive sensor being adapted to measure at least one characteristic of motor oil between at least two of said sensing electrodes, each of said sensing electrodes being covered by a silicone coating.

10. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 9 wherein said at least one capacitive sensor comprises an oil level sensor.

11. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 9 further comprising:

a tilt sensor mechanically coupled to said housing, said tilt sensor providing an output signal indicative of an orientation of said tilt sensor relative to a vector representing forces applied to said tilt sensor.

12. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 11 wherein said tilt sensor is coupled to said housing in a substantially fixed orientation relative to the vehicle.

13. A sensor assembly for measuring characteristics of motor oil in a vehicle, the sensor assembly comprising:

a housing adapted to be mechanically coupled to a vehicle; and

at least one capacitive sensor mechanically coupled to said housing, said at least one capacitive sensor including a plurality of sensing electrodes, said at least one capacitive sensor being adapted to measure at least one characteristic of motor oil between at least two of said sensing electrodes, each of said sensing electrodes being covered by a nonconductive coating of silicone material;

whereby the soot build-up which occurs on capacitive sensors employed to sense the oil in certain types of internal combustion engines is substantially reduced or eliminated.

14. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 13 wherein said at least one capacitive sensor comprises an oil level sensor.

15. The sensor assembly for measuring characteristics of motor oil in a vehicle of claim 13 further comprising:

a tilt sensor mechanically coupled to said housing, said tilt sensor providing an output signal indicative of an orientation of said tilt sensor relative to a vector representing forces applied to said tilt sensor.

16. A sensor assembly for measuring characteristics of motor oil in a vehicle, the sensor assembly comprising:

a housing mechanically coupled to a vehicle in a substantially fixed orientation relative to the vehicle, said housing being formed and positioned relative to other components of the vehicle to receive a volume of motor oil proportionally related to a total volume of motor oil in the vehicle;

at least one capacitive sensor mechanically coupled to said housing, said at least one capacitive sensor including a plurality of sensing electrodes, said at least one capacitive sensor being adapted to measure at least one characteristic of motor oil between at least two of said sensing electrodes, each of said sensing electrodes being covered by a silicone coating; and

said at least one capacitive sensor comprising an oil level sensor; and

further comprising an oil deterioration sensor.

17. A sensor assembly for measuring characteristics of motor oil in a vehicle, the sensor assembly comprising:

a housing mechanically coupled to a vehicle in a substantially fixed orientation relative to the vehicle, said housing being formed and positioned relative to other components of the vehicle to receive a volume of motor oil proportionally related to a total volume of motor oil in the vehicle;

at least one capacitive sensor mechanically coupled to said housing, said at least one capacitive sensor including a plurality of sensing electrodes, said at least one capacitive sensor being adapted to measure at least one characteristic of motor oil between at least two of said sensing electrodes, each of said sensing electrodes being covered by a silicone coating; and

said at least one capacitive sensor further comprising an oil deterioration sensor.

18. A sensor assembly for measuring characteristics of motor oil in a vehicle, the sensor assembly comprising:

a housing adapted to be mechanically coupled to a vehicle;

at least one capacitive sensor mechanically coupled to said housing, said at least one capacitive sensor including a plurality of sensing electrodes, said at least one capacitive sensor being adapted to measure at least one characteristic of motor oil between at least two of said sensing electrodes, each of said sensing electrodes being covered by a nonconductive coating; and

said at least one capacitive sensor comprising an oil deterioration sensor.