Oil level sensor system

• US 5,687,687 A
• Filed: 06/07/1995
• Issued: 11/18/1997
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Duffer, Bradly G., Zopff, Lynn S., Till, Mary L., Trueblood, Jimmie J.
• Primary Examiner(s): Solis, Erick R.
• Application Number:
  US08/477,294
• Time in Patent Office: 895 Days
• Field of Search: 123/196 S, 123/195 C, 73/293, 340/450, 340/450.3
• US Class Current: 123/196.00S
• CPC Class Codes: F01M 11/0004 Oilsumps
• CPC Class Codes: F01M 11/12 concerning lubricant level
• CPC Class Codes: G01F 23/2921 for discrete levels

Abstract

A fluid level sensor system for a vehicle oil pan includes a fluid level sensor assembled to the oil pan which has a first LED/phototransistor sensor electrically arranged and responsive to a low oil level in the oil pan for generating a low level voltage signal. The fluid level sensor also includes a second LED/phototransistor sensor which is electrically arranged and responsive to a high oil level in the oil pan for generating a high level voltage signal. The low level voltage signal and the high level voltage signal from the fluid level sensor are electrically connected to an electronic control module (ECM) which receives and processes the two signals and activates a warning lamp with a flashing illumination to identify a low oil level condition and a constantly on illumination to identify a high oil level condition. The operation of the ECM is controlled by a flow logic algorithm.

Claims

1. A fluid level sensor system operable to indicate either when the fluid level in a movable reservoir is below a predetermined low level limit or when the fluid level in the reservoir is above a predetermined high level limit, said fluid level sensor system comprising:

a movable fluid reservoir which is constructed and arranged to be oriented in a plurality of different tilt angles, said plurality of different tilt angles defining a plurality of cross over points based upon the fluid level in said reservoir;

a fluid level sensor assembled to said fluid reservoir at a location which is adjacent to said cross over points and having first sensor means responsive to a low fluid level in said fluid reservoir for generating a first level signal and having second sensor means responsive to a high fluid level in said fluid reservoir for generating a second level signal;

an electronic control module electrically connected to said fluid level sensor for receiving and processing said first and second signals; and

a warning indicator electrically connected to said electronic control module for providing a first warning signal corresponding to said first level signal and a second warning signal corresponding to said second level signal, said first warning signal being different from said second warning signal so as to differentiate between a low level fault and a high level fault.

2. The fluid level sensor system of claim 1 wherein the fluid is oil and wherein the fluid reservoir is an oil pan.

3. The fluid level sensor system of claim 2 wherein said fluid level sensor is an electronic arrangement of two LED/phototransistor sensors.

4. The fluid level sensor system of claim 3 wherein said warning indicator is a fluids lamp.

5. The fluid level sensor system of claim 4 wherein one of said first and second warning signals is a flashing mode of illumination from said lamp and the other warning signal is a constantly on mode of illumination from said lamp.

6. The fluid level sensor system of claim 1 wherein said fluid level sensor is an electronic arrangement of two LED/phototransistor sensors.

7. The fluid level sensor system of claim 1 wherein said warning indicator is a fluids lamp.

8. The fluid level sensor system of claim 1 wherein the operation of the electronic control module is controlled by an algorithm programmed into said electronic control module.

9. An oil level sensor for a movable vehicle oil pan for providing either a low oil level signal or a high oil level signal when the oil level in the oil pan is outside of an acceptable oil level range, the oil pan having the ability to assume different tilt angles, the tilt angles defining a plurality of cross over points based upon the fluid level in said vehicle oil pan, said oil level sensor comprising:

a main body portion constructed and arranged for assembly into said oil pan at a location which is adjacent to said cross over points; and

an electronic module positioned within said main body portion and having a first LED/phototransistor sensor for sensing a low oil level in said oil pan and a second LED/phototransistor sensor for sensing a high oil level in said oil pan, said low and high oil levels being predetermined based upon oil pan geometry and volume.

10. The oil level sensor of claim 9 wherein said low oil level signal is a low voltage signal.

11. The oil level sensor of claim 10 wherein said high oil level signal is a high voltage signal which is higher than said low voltage signal.

12. A fluid level sensor system operable to indicate either when the fluid level in a movable reservoir is below a predetermined low level limit or when the fluid level in the reservoir is above a predetermined high level limit, said fluid level sensor system comprising:

a movable fluid reservoir which is constructed and arranged to be oriented in a plurality of different tilt angles, said plurality of different tilt angles defining a plurality of cross over points based upon the fluid level in said reservoir;

a fluid level sensor positioned within said fluid reservoir at a location which is adjacent to said cross over points and having first sensor which is responsive to a low fluid level in said fluid reservoir and which is constructed and arranged for generating a first level signal and having a second sensor which is responsive to a high fluid level in said fluid reservoir and which is constructed and arranged for generating a second level signal;

an electronic control module electrically connected to said fluid level sensor for receiving and processing said first and second signals; and

a warning indicator electrically connected to said electronic control module for providing a first warning signal corresponding to said first level signal and a second warning signal corresponding to said second level signal and a second warning signal corresponding to said second level signal.

13. The fluid level sensor system of claim 12 wherein said first and second sensors are each an LED/phototransistor combination.

14. The fluid level sensor system of claim 13 wherein said warning indicator is a fluids lamp.

15. The fluid level sensor system of claim 12 wherein the operation of the electronic control module is controlled by an algorithm programmed into said electronic control module.