Diagnostic method and device for a purge valve of a hybrid motor vehicle
View Patent ↗A method for detecting the blockage of the purge valve ( 4 ) of a vapor filter ( 3 ) for a hybrid fuel drive vehicle including at least one internal combustion engine ( 1 ) and one electric generator/motor, includes a step of making the electric motor drive the internal combustion engine ( 1 ) so as to keep the internal combustion engine ( 1 ) at a constant speed, during a start-up phase or a phase preliminary to stopping, and at least one sequence of the following steps during this time that the internal combustion engine is kept at a constant speed: a step of opening the purge valve ( 4 ); a step of measuring at least one operating parameter of the electric motor; a step of comparing the values of the measured parameter before and after opening the purge valve ( 4 ) and of determining whether the variation in the parameter is above a predetermined threshold.
1. A method for detecting blockage of a purge valve ( 4 ) of a gasoline vapor filter ( 3 ) for a hybrid drive vehicle comprising at least one internal combustion engine ( 1 ) and one electric generator/motor ( 15 ), the method comprising:
control electronics ( 10 ) making the electric generator/motor ( 15 ) drive the internal combustion engine ( 1 ) so as to keep said internal combustion engine ( 1 ) at a constant non-idling speed, during a start-up phase or a phase preliminary to stopping, and
at least one sequence of the following steps during a time that the electric generator/motor ( 15 ) drives the internal combustion engine at a constant speed:
changing the state of the purge valve ( 4 ),
measuring at least one operating parameter of the electric generator/motor ( 15 ) before and after changing the state of the purge valve ( 4 ), and
comparing the values of the measured parameter before and after the change of state of the purge valve ( 4 ) and of determining whether the variation in said parameter is above a predetermined threshold.
2. The method as claimed in claim 1 , further comprising a repeat of the steps as described above so as to obtain a measurement that is statistically significant.
3. The method as claimed in claim 1 , wherein the electric generator/motor ( 15 ) operating parameter is a parameter indicative of torque.
4. The method as claimed in claim 1 , wherein the internal combustion engine ( 1 ) is operated without fuel injection during the step in which the internal combustion engine ( 1 ) is held at a constant non-idling speed.
5. A device for detecting blockage of a purge valve ( 4 ) of a gasoline vapor filter ( 3 ) of a vehicle internal combustion engine ( 1 ), comprising:
means for making an electric generator/motor ( 15 ) drive the internal combustion engine ( 1 ) at a constant non-idling speed during a start-up phase or a phase preliminary to stopping,
means for measuring at least one operating parameter of the electric generator/motor ( 15 ), and
means of comparing the values of the measured parameter before and after a change in state of the purge valve ( 4 ) and of determining whether the variation in said parameter is above a predetermined threshold.
6. The device as claimed in claim 5 , wherein the means of measuring at least one operating parameter of the electric generator/motor ( 15 ) comprise an electric generator/motor torque sensor ( 16 ).
7. The method as claimed in claim 2 , wherein the electric generator/motor ( 15 ) operating parameter is a parameter indicative of torque.
8. The method as claimed in claim 2 , wherein the internal combustion engine ( 1 ) is operated without fuel injection during the step in which the internal combustion engine ( 1 ) is held at a constant non-idling speed.
9. The method as claimed in claim 3 , wherein the internal combustion engine ( 1 ) is operated without fuel injection during the step in which the internal combustion engine ( 1 ) is held at a constant non-idling speed.
10. The method as claimed in claim 7 , wherein the internal combustion engine ( 1 ) is operated without fuel injection during the step in which the internal combustion engine ( 1 ) is held at a constant non-idling speed.