Method for monitoring an oil flow in an oil cooling circuit

Patent metadata

Field	Value
Publication number	US-12492959-B2
Application number	US-202017760691-A
Country	US
Kind code	B2
Filing date	Sep 4, 2020
Priority date	Sep 16, 2019
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

A method for monitoring an oil flow, generated by an oil pump, in an oil cooling circuit of a thermal management system, includes: arranging a first pressure sensor at a first point in the cooling circuit; arranging a second pressure sensor at a second point in the oil cooling circuit; determining pressure difference values based on recorded pressures; and comparing the pressure difference values with a predeterminable comparison value for the pressure difference so as to check for a fault.

First claim

The invention claimed is:

1 . A method for monitoring an oil flow, generated by an oil pump ( 23 ), in an oil cooling circuit ( 5 ) of a thermal management system ( 1 ), the method comprising:
arranging a first pressure sensor ( 21 ) at a first point in the cooling circuit ( 5 ); arranging a second pressure sensor ( 22 ) at a second point in the oil cooling circuit ( 5 ),
wherein the first pressure sensor ( 21 ) and/or the second pressure sensor ( 22 ) comprise a monitoring system;
determining pressure difference values based on recorded pressures;
comparing the pressure difference values with a predeterminable comparison value for the pressure difference so as to check for a fault in the first pressure sensor ( 21 ) and/or the second pressure sensor ( 22 );
one of operating the oil pump in a monitoring system no-fault condition and not operating the oil pump in a fault condition;
monitoring the oil flow in a pressure reduction phase (phase III);
after the oil pump ( 23 ) is deactivated, determining at least one pressure difference value and comparing the pressure difference value with a predeterminable pressure comparison value; and
comparing, after a pre-determinable debounce time, the recorded pressures with a predeterminable pressure target value related to the debounce time to check for a fault in the pressure reduction phase (phase III).

2 . The method as claimed in claim 1 , further comprising:
monitoring the oil flow:
in a pressure build-up phase (phase I), and/or
in an operating phase (phase II),

determining at least one of the pressure difference values in respective phases; and
comparing the pressure difference value with a predeterminable, phase-related comparison value for the pressure difference so as to check for a fault.

3 . The method as claimed in claim 2 , further comprising:
before the oil pump ( 23 ) is activated by way of the pressure difference values determining, checking for an electrical fault in the pressure sensors ( 21 , 22 ) by comparing the determined pressure difference values with a predeterminable first pressure comparison value (SW 1 ).

4 . The method as claimed in claim 3 , further comprising: after the oil pump ( 23 ) has been activated during the pressure build-up phase (phase I), determining a pressure difference value at least for one pressure stroke of the oil pump ( 23 ) and comparing the pressure difference value is compared with a predeterminable second pressure comparison value (SW 2 ) so as to check for a fault in the pressure build-up phase (phase I).

5 . The method as claimed in claim 4 , further comprising:
comparing the time until the pressure stroke is reached with a pre-determinable time comparison value so as to check for a fault in the pressure build-up phase (phase I).

6 . The method as claimed in claim 5 , further comprising:
during the operating phase (phase II), determining at least one pressure difference value and comparing the determined at least one pressure difference with a predeterminable third pressure comparison value (SW 3 ) so as to check for an electrical fault in the pressure sensors ( 21 , 22 ).

7 . The method as claimed in claim 6 , further
comprising: determining an average value of the recorded pressures; and comparing the average value with a predeterminable fourth pressure comparison value (SW 4 ) so as to check for a fault in the operating phase (phase II).

8 . The method as claimed in claim 1 ,
wherein during the pressure reduction phase (phase III), the predeterminable pressure is a predeterminable fifth pressure comparison value (SW 5 ).

9 . The method as claimed in claim 1 , wherein the oil cooling circuit ( 5 ) is configured to cool an electric motor ( 13 ), by being thermally connected to a coolant circuit ( 3 ) via a heat exchanger ( 20 ).

10 . The method as claimed in claim 1 , wherein the first and second pressure sensors ( 21 , 22 ) are each arranged upstream of a heat exchanger ( 20 ) and downstream of the oil pump ( 23 ).

11 . A non-transitory computer-readable data storage medium storing a computer program, comprising program code which, when executed on a processor of a processor controlled apparatus, causes the apparatus to perform the method as claimed in claim 1 .

12 . A control device having a computer program for carrying out the method as claimed in claim 1 .

13 . A vehicle having the control device as claimed in claim 12 .

Assignees

• Vitesco Tech Gmbh

Inventors

• Eser Gerhard
• Brettner Sebastian
• Dillinger Manuel
• Feulner Markus
• Zhang Hong

Classifications

• H02K9/19

  for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil · CPC title

• H02K11/20

  for measuring, monitoring, testing, protecting or switching (rectifiers H02K11/04; power electronics H02K11/33) · CPC title

• B60K2001/006

  the electric motors · CPC title

• B60K2001/003

  with means for cooling the electrical propulsion units · CPC title

• G01L27/007 Primary

  Malfunction diagnosis, i.e. diagnosing a sensor defect · CPC title