Vehicle hydraulic device

Abstract

A check valve provided makes it possible to operate a vane pump smoothly even at the start of the vane pump by maintaining an oil pressure in backpressure oil passages inside the vane pump while the vane pump is stopped. The check valve opens at the point in time when an oil pressure control device, to which a working fluid is supplied from the vane pump, has been filled with the working fluid and the oil pressure in discharge oil passages communicating with the oil pressure control device has risen and exceeded the oil pressure in the backpressure oil passages. Thus, the check valve is prevented from opening and closing repeatedly, so that the durability of the check valve is improved.

What is claimed is: 
     
         1 . A vehicle hydraulic device comprising:
 a vane pump that is driven to rotate by an engine, the vane pump including a pump housing, a plurality of vanes, and a rotor,
 the pump housing having an inner peripheral cam surface with an elliptical sectional shape, 
 the plurality of vanes being provided inside the pump housing, 
 the rotor providing vane housing grooves that house the plurality of vanes so as to be movable in a radial direction of the rotor; and 
   an oil pressure control circuit including backpressure oil passages and discharge oil passages,
 the backpressure oil passages being configured to supply a backpressure to the plurality of vanes inside the vane housing grooves, 
 the discharge oil passages being configured to: (i) introduce a working fluid discharged from the vane pump, and (ii) supply the working fluid to a device other than the vehicle hydraulic device, 
   a check valve provided between the backpressure oil passages and the discharge oil passages, the check valve being configured to: (i) open when an oil pressure of the working fluid in the discharge oil passages discharged from the vane pump is higher than the oil pressure in the backpressure oil passages, and (ii) block a flow of the working fluid when the oil pressure of the working fluid in the discharge oil passages discharged from the vane pump is equal to or lower than the oil pressure in the backpressure oil passages.   
     
     
         2 . A vehicle hydraulic device comprising:
 a vane pump that is driven to rotate by an engine, the vane pump including a pump housing, a plurality of vanes, a rotor, and check valves,
 the pump housing having an inner peripheral cam surface with an elliptical sectional shape, 
 the plurality of vanes being provided inside the pump housing, 
 the rotor providing vane housing grooves that house the plurality of vanes so as to be movable in a radial direction of the rotor, 
 the check valves being configured to open to allow a flow of a working fluid and close to shut off the flow of the working fluid; and 
   an oil pressure control circuit including backpressure oil passages and discharge oil passages,
 the backpressure oil passages being configured to supply a backpressure to the plurality of vanes inside the vane housing grooves, 
 the discharge oil passages being configured to: (i) introduce the working fluid discharged from the vane pump, and (ii) supply the working fluid to a device other than the vehicle hydraulic device, wherein 
   the check valves are interposed between the backpressure oil passages and the discharge oil passages, and   the check valves are configured to: (i) open when an oil pressure of the working fluid in the discharge oil passages discharged from the vane pump is higher than the oil pressure in the backpressure oil passages, and (ii) block the flow of the working fluid when the oil pressure of the working fluid in the discharge oil passages discharged from the vane pump is equal to or lower than the oil pressure in the backpressure oil passages.