Method for identifying an operating state of an engine soak timer

• US 6,718,256 B1
• Filed: 10/04/2001
• Issued: 04/06/2004
• Est. Priority Date: 10/04/2001
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Davison, Lynn Edward, Holmes, John William
• Primary Examiner(s): Wolfe, Willis R.
• Assistant Examiner(s): Hoang, Johnny H.
• Application Number:
  US09/682,671
• Time in Patent Office: 915 Days
• Field of Search: 123/41.04, 123/41.05, 123/41.12, 123/41.13, 123/179.4, 123/179.24, 123/198.D, 701/35, 701/101, 701/102, 701/113, 701/115, 374/145
• US Class Current: 701/113
• CPC Class Codes: F01P 11/16 concerning coolant temperature F01P11/20 takes precedence
• CPC Class Codes: F01P 2031/30 Cooling after the engine is stopped
• CPC Class Codes: F02D 2250/14 Timing of measurement, e.g. synchronisation of measurements to the engine cycle
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for determining the existence of a “short time” type state within a vehicle control assembly 10. The method requires the measurement of the temperature 59 of engine coolant 16 at a first time 61 and the determination and/or the inferential creation of the temperature 60 of the engine coolant 16 at a second and later time 62. A “short time” type state is identified when the temperature 60 at the second time 62 is greater than or equal to the temperature 59 at the first time 61.

Claims

1. A method for use by a vehicle control assembly of the type having a soak timer and adapted for use in combination with an internal combustion engine, said method being effective to ascertain the existence of a short time state within the soak timer, said method comprising the steps of determining whether the engine has been recently activated;

creating a cooling signature for a certain material;

measuring the temperature of said certain material at a first time;

inferring the temperature of said certain material at a second time by use of said cooling signature;

comparing said measured temperature and said inferred temperature; and

identifying the existence of said short time state by use of said comparison.

2. The method of claim 1 wherein said certain material comprises engine coolant.

3. The method of claim 1 wherein said second time is later than said first time.

4. The method of claim 1 wherein said short time state is identified only if said measured temperature at said second time is greater than said inferred temperature at said first time.

5. The method of claim 4 wherein said comparison is made only if said engine has been recently activated.

6. The method of claim 5 wherein said second time is about one hour later than said first time.

7. The method of claim 1 further comprising the steps of creating a plurality of cooling signatures;

and selecting said cooling signature from said plurality of cooling signatures.

8. The method of claim 7 wherein said cooling signature is selected by use of an ambient temperature.

9. The method of claim 8 wherein said cooling signature is selected by use of an engine coolant temperature.

10. The method of claim 9 further comprising the step of providing an indication upon the identification of said existence of said short time state.