Method for assessing the deterioration of motor oil

• US 6,786,080 B2
• Filed: 12/20/2002
• Issued: 09/07/2004
• Est. Priority Date: 02/24/2000
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Buch, Stephan, Jakoby, Bernhard, Schatz, Oliver
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Rogers, David A.
• Application Number:
  US10/204,762
• Publication Number:
  US 20030150256A1
• Time in Patent Office: 627 Days
• Field of Search: 73/10, 73/530.5, 73/540.1, 73/540.2, 73/544.2, 73/544.3
• US Class Current: 73/54.01
• CPC Class Codes: F01M 11/10 Indicating devices; Other safety devices
• CPC Class Codes: F01M 2011/1473 by considering temperature
• CPC Class Codes: F01M 2011/148 by considering viscosity
• CPC Class Codes: F16N 2270/52 Viscosity
• CPC Class Codes: G01N 2011/0013 Temperature compensation

Abstract

A method for assessing the deterioration of motor oil is provided, in which the oil viscosity of the motor oil is measured by a sensor, and the length of an oil-change interval is determined in an evaluating electronics having a display device. According to the present invention, it is provided that a temperature sensor for the simultaneous determination of the oil temperature is assigned to the sensor for measuring the oil viscosity, and the oil viscosity and oil temperature are measured in the cooling phase of the engine after it has been switched off.

Claims

1. A method for assessing a deterioration of a motor oil for determining a length of an oil-change interval of the motor oil, comprising:

measuring the viscosity of the motor oil by a viscosity sensor at a plurality of times;

assigning to the viscosity sensor a temperature sensor;

measuring the temperature of the motor oil by the temperature sensor at substantially the same times as the plurality of viscosity measurements;

analyzing the plurality of viscosity measurements and the plurality of temperature measurements to obtain an indication of the deterioration of the motor oil; and

determining a length of an oil-change interval based on the indication of the deterioration of the motor oil, using evaluating electronics;

wherein the measuring of the oil viscosity and the measuring of the oil temperature occur in a cooling phase of an engine after the engine has been switched off.

2. The method as recited in claim 1, further comprising:

regulating and monitoring, by an engine control device that is assigned to the engine, the measuring of the oil viscosity, the measuring of the oil temperature, and the determining of the length of the oil-change interval.

3. The method as recited in claim 1, wherein the measuring of the oil viscosity and the measuring of the oil temperature are performed in a time interval of about 10 minutes to about 100 minutes after the engine has been switched off.

4. The method as recited in claim 1, wherein the evaluating electronics for determining the length of the oil-change interval is a computing device arranged in an instrument panel, the computing device being driven and monitored by an engine control unit.

5. A method for assessing a deterioration of an oil circulated in a device during use, comprising:

taking a plurality of oil viscosity readings after the device has been switched off and the oil is no longer circulating;

taking a plurality of oil temperature readings at substantially the same times as the oil viscosity readings; and

assessing the deterioration of the motor oil based on the oil viscosity readings and the oil temperature readings.

6. The method of claim 5, wherein the oil temperature is elevated during use, and wherein the oil viscosity and oil temperature readings are taken during a cooling phase of the device.

7. The method of claim 6, further comprising:

determining a length of an oil-change interval using evaluating electronics including a display device.

8. The method of claim 7, wherein the device is a motor and the oil is a motor oil.

9. The method of claim 8, wherein measuring of the oil viscosity and oil temperature is performed in a time interval of about 10 minutes to about 100 minutes after the motor has been switched off.

10. A detector for detecting deterioration of oil circulated in a device, comprising:

an oil viscosity sensor configured to measure oil viscosity at a plurality of times after the device has been switched off and the oil is no longer circulating;

a temperature sensor configured to measure oil temperature at substantially the same times as the oil viscosity measurements; and

a computing unit configured to assess the deterioration of the motor oil based on the plurality of oil viscosity measurements and the plurality of oil temperature measurements taken after the device has been switched off and the oil is no longer circulating.

11. The detector of claim 10, wherein the oil temperature is elevated during circulation in the device and the detector is configured to take oil viscosity readings and the oil temperature readings during a cooling phase of the device.

12. The detector of claim 11, wherein the computing unit is configured to determine a length of an oil-change interval using evaluating electronics including a display device.

13. The detector of claim 12, wherein the computing unit is controlled and monitored by an engine control unit.

14. The detector of claim 13, wherein the device is a motor and the oil is a motor oil.

15. The detector of claim 10, wherein the detector is configured to take the oil temperature and the oil viscosity readings in a time interval of about 10 minutes to about 100 minutes after the device has been switched off.