Method of diagnosing oil leak of engine clutch in hybrid electric vehicle
View Patent ↗The present disclosure provides a method of diagnosing an oil leak of an engine clutch in a hybrid electric vehicle including: when the engine starts up in the hybrid electric vehicle, operating a hydraulic actuator provided in the engine clutch, wherein the hydraulic actuator is configured to perform engagement or disengagement between an engine and a motor; determining displacement of a piston provided in the hydraulic actuator and pressure for any displacement of a plurality of the displacements of the piston; calculating a pressure gradient based on the displacement of the piston and the pressure for any displacement of the plurality of the displacements of the piston; and determining the oil leak of the engine clutch based on the pressure gradient.
1. A method of diagnosing an oil leak of an engine clutch in a hybrid electric vehicle, the method comprising:
when an engine starts up in the hybrid electric vehicle, operating a hydraulic actuator provided in the engine clutch, wherein the hydraulic actuator is configured to perform engagement or disengagement between the engine and a motor;
determining displacement of a piston provided in the hydraulic actuator and pressure for any displacement of a plurality of the displacements of the piston;
calculating a pressure gradient based on the displacement of the piston and the pressure for any displacement of the plurality of the displacements of the piston; and
determining the oil leak of the engine clutch based on the pressure gradient,
wherein the pressure gradient is calculated based on the equation:
Grad
=
P
max
-
P
end
L
(
P
max
)
-
L
(
P
end
)
,
wherein Grad, P max , Pend, L( Pmax ), and end, L(P end ) denote the pressure gradient (G), maximum pressure (bar) among the determined pressure, pressure (bar) at the maximum displacement among the determined displacement, displacement (um) at the P max , and displacement (um) at the P end , respectively.
2. The method of claim 1 , wherein determining the displacement of the piston provided in the hydraulic actuator and the pressure for any displacement of the plurality of the displacements of the piston comprises:
determining a shift in the displacement of the piston, wherein the displacement of the piston varies depending on operation of the hydraulic actuator.
3. The method of claim 2 , wherein determining the displacement of the piston provided in the hydraulic actuator and the pressure for any displacement of the plurality of the displacements of the piston further comprises:
determining pressure at any position of a plurality of positions corresponding to the displacement of the piston.
4. The method of claim 3 , wherein determining the displacement of the piston provided in the hydraulic actuator and the pressure for any displacement of the plurality of the displacements of the position further comprises:
determining a position of the maximum pressure among the plurality of the positions corresponding to the displacement of the piston; and
determining a pressure of the maximum displacement among the plurality of the positions corresponding to the displacement of the piston.
5. The method of claim 1 , wherein determining the oil leak of the engine clutch based on the pressure gradient further comprises:
when the pressure gradient is equal to or greater than a reference value, determining that the oil is leaking in the engine clutch.
6. The method of claim 1 , further comprising:
when it is determined that the oil is leaking in the engine clutch, warning the oil leak of the engine clutch through a dashboard of the hybrid electric vehicle.