Vehicle hydraulic control unit

Abstract

A vehicle hydraulic control unit capable of preventing a vane from being pulled into a vane groove when a vane pump driven by an engine stops. The present hydraulic control unit supplies discharge oil in an external pump to a vane back pressure chamber of a vane pump, when an engine stops.

1 . A vehicle hydraulic control unit comprising:
 a vane pump driven by an engine,   the vane pump accommodates vanes in many vane grooves, which are radially arranged on a rotor provided to a pump shaft, so as to be capable of protruding to or retracting from the vane grooves, a cam ring surrounds the rotor and the vanes to define a pump chamber, and discharge oil from the pump chamber is supplied to a center-side vane back pressure chamber in the vane groove, wherein   discharge oil from an external oil pressure supplying apparatus can be supplied to the vane back pressure chamber of the vane pump during stoppage of the engine.   
     
     
         2 . A vehicle hydraulic control unit comprising:
 a vane pump driven by an engine,   the vane pump accommodates vanes in many vane grooves, which are radially arranged on a rotor provided to a pump shaft, so as to be capable of protruding to or retracting from the vane grooves, a cam ring surrounds the rotor and the vanes to define a pump chamber, and a side plate provided along the cam ring communicates a discharge port corresponding to a discharge-side pump chamber and a vane back pressure supplying port corresponding to a center-side vane back pressure chamber in the vane groove, wherein   discharge oil from an external oil pressure supplying apparatus can be supplied to the discharge port of the vane pump during stoppage of the engine.   
     
     
         3 . A vehicle hydraulic control unit according to  claim 2 , wherein
 the external oil pressure supplying apparatus includes an external pump, and the discharge oil from the external pump can be supplied to a discharge pipe line of the vane pump through a one-way valve.   
     
     
         4 . A vehicle hydraulic control unit according to  claim 1 , wherein
 the external oil pressure supplying apparatus includes an accumulator in which pressure is accumulated by the discharge oil of the vane pump.   
     
     
         5 . A vehicle hydraulic control unit according to  claim 2 , wherein
 the external oil pressure supplying apparatus includes an accumulator in which pressure is accumulated by the discharge oil of the vane pump.   
     
     
         6 . A vehicle hydraulic control unit according to  claim 3 , wherein
 the external pump is driven by an electric motor, and the discharge oil from the external pump is supplied to a discharge pipe line of the vane pump through a check valve serving as a one-way valve.   
     
     
         7 . A vehicle hydraulic control unit according to  claim 4 , wherein
 the hydraulic fluid accumulated in the accumulator is supplied to the vane back pressure chamber, when at least one of a temporal stoppage of a vehicle, a stoppage of the rotation of the engine, a stoppage of the rotation of the vane pump, or reduction in the discharge oil pressure of the vane pump occurs.   
     
     
         8 . A vehicle hydraulic control unit according to  claim 5 , wherein
 the hydraulic fluid accumulated in the accumulator is supplied to the vane back pressure chamber, when at least one of a temporal stoppage of a vehicle, a stoppage of the rotation of the engine, a stoppage of the rotation of the vane pump, or reduction in the discharge oil pressure of the vane pump occurs.   
     
     
         9 . A vehicle hydraulic control unit according to  claim 6 , wherein
 the electric motor is driven when at least one of a temporal stoppage of a vehicle, a stoppage of the rotation of the engine, a stoppage of the rotation of the vane pump, or reduction in the discharge oil pressure of the vane pump is detected.