| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein air may be sucked in an advance chamber and a delay chamber at the drop of oil pressure when hydraulic variation is increased with respect to a VCT in which hydraulic variation occurs when a vane rotor receives a torque fluctuation of a camshaft. SOLUTION: A sleeve 11 is provided with: first and second fluid introducing parts 24, 25 (diametrically enlarged parts) for leading oil in a distribution chamber 23 to some midpoints in sealing rangesα,α'. Oil pressure is fed to some midpoints in the sealing rangesα,α' by the first and second fluid introducing parts 24, 25, so that average oil pressure in an advance chamber and a delay chamber is increased. Thus, the advance chamber and delay chamber are prevented from being depressurized. In a neutral state of a spool 12, the distribution chamber 23 and a first and second output ports 16, 18 communicate with each other through the medium of small sealing rangesβ,β' between a first and second clearances acting as a fixed throttle, so that an oil pressure difference between the first and second output ports 16, 18 with respect to a stroke amount of the spool 12 is suppressed. As a result, the precision of advance control of the camshaft is improved. COPYRIGHT: (C)2007,JPO&INPIT
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