Apparatus and method for diagnosing failure of piston cooling jet of engine

Abstract

An apparatus for diagnosing failure of a piston cooling jet of an engine includes an oil line for a piston cooling jet arranged in a cylinder block in a longitudinal direction, a piston cooling jet mounted at the oil line for the piston cooling jet to inject oil to a piston, a solenoid valve mounted at an inlet of the oil line for the piston cooling jet to selectively allow an injection operation of the piston cooling jet, an oil pressure detecting means mounted at the oil line for the piston cooling jet after the solenoid valve to detect oil pressure, and a control unit configured to receive a detection signal of the oil pressure detecting means and determine whether the solenoid valve is in a failure state.

What is claimed is: 
     
         1 . An apparatus for diagnosing a failure of a piston cooling jet of an engine, comprising:
 an oil line for a piston cooling jet arranged in a cylinder block in a longitudinal direction;   a piston cooling jet mounted at the oil line for the piston cooling jet to inject oil to a piston;   a solenoid valve mounted at an inlet of the oil line for the piston cooling jet to selectively allow an injection operation of the piston cooling jet;   an oil pressure detecting means mounted at the oil line for the piston cooling jet after the solenoid valve to detect oil pressure; and   a control unit configured to receive a detection signal of the oil pressure detecting means and determine whether the solenoid valve is in a failure state.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 a driver warning means operated by the control unit when it is determined that the solenoid valve is in a failure state.   
     
     
         3 . The apparatus of  claim 1 , wherein the oil pressure detecting means is an oil pressure switch which is switched at a time of detecting oil pressure to generate a pressure detection signal. 
     
     
         4 . A method of diagnosing a failure of a piston cooling jet of an engine, comprising:
 Selectively opening and closing a solenoid valve in order to supply oil to an oil line for a piston cooling jet or block oil according to a running condition of an engine;   injecting, by the piston oil jet, oil flowing into the oil line for the piston cooling jet when the solenoid valve is opened;   blocking oil from flowing to the oil line for the piston cooling jet when the solenoid valve is closed and stopping an injection operation of the piston oil jet; and   detecting oil pressure within the oil line for the piston cooling jet, and determining that the solenoid valve is in a failure state when the oil pressure is not detected when the solenoid valve is opened or the oil pressure is detected when the solenoid valve is closed.   
     
     
         5 . The method of  claim 4 , wherein when the oil pressure is not detected when the solenoid valve is opened, it is determined that the solenoid valve has a failure in a closed state. 
     
     
         6 . The method of  claim 4 , wherein when the oil pressure is detected when the solenoid valve is closed, it is determined that the solenoid valve has a failure in the opened state. 
     
     
         7 . The method of  claim 4 , further comprising:
 operating, by a control unit, a driver warning means when it is determined that the solenoid valve is in a failure state.