Control valve apparatus

A control valve apparatus for a vehicle having a hydraulic system equipped with a main flow passage for feeding oil, discharged from an oil pump driven by an internal combustion engine, to each of lubricated engine parts, a branch passage branched from the main flow passage at a branched point, and a hydraulically-operated variable valve timing control device operated by a hydraulic pressure in the branch passage and having a lock mechanism configured to hold engine valve timing until the hydraulic pressure in the branch passage becomes greater than or equal to a specified pressure value, the control valve apparatus comprising:

• a spool valve configured to throttle the flow rate of the oil flowing through the portion of the main flow passage downstream of the branched point depending on an axial position of its spool, the axial position of the spool being obtained as a result of a sliding motion of the spool relative to a spool valve body, wherein
• the control valve apparatus is configured to adjust a flow rate of the oil flowing through a portion of the main flow passage downstream of the branched point,
• the control valve apparatus is configured to control the flow rate of the oil flowing through the portion of the main flow passage downstream of the branched point to a large flow-rate side of a variable flow-rate range, until a hydraulic pressure of the oil flowing through the main flow passage becomes greater than or equal to a predetermined pressure value after the engine has been started from its stopped state,
• the control valve apparatus is further configured to control the flow rate of the oil flowing through the portion of the main flow passage downstream of the branched point to a small flow-rate side of the variable flow-rate range, when the hydraulic pressure of the oil flowing through the main flow passage becomes greater than or equal to the predetermined pressure value after the engine has been started from its stopped state,
• the spool of the spool valve is slidably accommodated in a sliding-contact bore of a substantially cylindrical flow-passage portion of the spool valve body, the flow-passage portion of the spool valve body having at least one through hole formed to penetrate inner and outer peripheries of the flow-passage portion of the spool valve body,
• the spool has a substantially cylindrical flow-passage portion closed at one axial end and opening at the opposite axial end, the flow-passage portion of the spool having at least one through hole formed to penetrate inner and outer peripheries of the flow-passage portion of the spool and configured to be able to communicate the through hole of the flow-passage portion of the spool valve body depending on the axial position of the spool, and
• an upstream side of the main flow passage communicates the through hole of the flow-passage portion of the spool valve body, while a downstream side of the main flow passage communicates the opening end of the flow-passage portion of the spool, for throttling a flow of the oil flowing via a flow path between the through hole of the flow-passage portion of the spool valve body and the through hole of the flow-passage portion of the spool depending on the axial position of the spool.