Capacitive sensor assembly

• US 5,900,810 A
• Filed: 12/17/1996
• Issued: 05/04/1999
• 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: Le, Phuoc Vinh, Park, Kyong M, Nassar, Marcos A.
• Primary Examiner(s): Wu, Daniel J.
• Application Number:
  US08/767,808
• Time in Patent Office: 868 Days
• Field of Search: 340/438, 340/439, 340/440, 340/450.3, 340/459, 340/460, 340/612, 340/618, 340/689, 340/693.5, 33/366, 123/196 R, 123/196 CP, 123/196 M, 123/196 S, 123/198 D, 324/71.1, 324/441, 324/439, 324/324, 324/663, 324/664, 324/665, 324/689, 324/698, 73/53.05, 73/61.74, 73/117.3, 73/295, 73/304 R, 73/304 C, 180/271, 180/277, 180/279, 180/282
• 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 includes a tilt sensor, an oil level sensor, an oil temperature sensor and an oil deterioration sensor, as well as associated output signal conditioning electronics integrated within a common assembly. The sensor assembly is configured to receive a volume of motor oil proportional to a total volume of oil in an engine. The oil level sensor, oil temperature sensor and oil deterioration sensors include electrodes which are completely or partially immersed in the volume of motor oil depending upon the total volume of oil in the engine. The tilt sensor includes only two electrodes both of which are at least partially immersed within a controlled volume of dielectric fluid which is physically and electrically isolated from the volume of motor oil. One of the electrodes of the tilt sensor is completely immersed in the controlled volume of dielectric fluid independent of an angle of the tilt sensor relative to a vector representing forces such as gravity applied to the tilt sensor.

Claims

1. A multifunctional 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, the housing including a chamber for receiving motor oil of the vehicle, the 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, the chamber including a substantially cylindrical inner wall; and

a plurality of sensors positioned within the housing for measuring characteristics of the motor oil, at least one of the sensors including an electrode substantially cylindrical in shape and fitted within the chamber.

2. The multifunctional sensor assembly of claim 1 wherein the at least one of the sensors comprises one of an oil deterioration sensor and an oil level sensor.

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

a plurality of chambers interconnected to form a single housing, at least one of the chambers receiving motor oil of a vehicle; and

a plurality of sensors mechanically coupled to the chambers, the sensors being adapted to measure characteristics of the motor oil.

4. The multifunctional sensor assembly of claim 3 further comprising:

a tilt sensor mechanically coupled to at least one of the plurality of chambers, the tilt sensor being adapted to provide an output signal indicative of an orientation of the tilt sensor relative to a vector representing forces applied to the tilt sensor.

5. The multifunctional sensor assembly of claim 3 wherein at least one of the sensors is only partially submerged in the motor oil.

6. The multifunctional sensor assembly of claim 3 wherein at least one of the sensors is electrically isolated from the motor oil.

7. The multifunctional sensor assembly of claim 3 wherein the sensors further comprise an oil deterioration sensor and a tilt sensor.

8. The multifunctional sensor assembly of claim 3 wherein the plurality of sensors comprise an oil deterioration sensor and an oil temperature sensor.

9. The multifunctional sensor assembly of claim 8 wherein the plurality of sensors further comprise a tilt sensor.

10. The multifunctional sensor assembly of claim 3 wherein the plurality of chambers include a first chamber 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 a second chamber separated from the volume of motor oil.

11. The multifunctional sensor assembly of claim 10 wherein the plurality of sensors comprise an oil level sensor positioned within the first chamber.

12. The multifunctional sensor assembly of claim 10 wherein the plurality of sensors comprise an oil deterioration sensor which is mechanically coupled to the second chamber and positioned relative to other components of the vehicle to receive a substantially constant volume of motor oil.

13. The multifunctional sensor assembly of claim 3 wherein the plurality of sensors comprise an oil deterioration sensor and an oil level sensor.

14. The multifunctional sensor assembly of claim 13 wherein the plurality of sensors further comprise a tilt sensor.

15. The multifunctional sensor assembly of claim 13 wherein the plurality of sensors further comprise an oil temperature sensor.

16. The multifunctional sensor assembly of claim 15 wherein the plurality of sensors further comprise a tilt sensor.