(57) A valve timing control apparatus for changing a relative rotational phase of a camshaft
(8 or 10) with respect to a crankshaft (2) using a hydraulic pressure of a hydraulic
oil supplied from an oil pump (16) includes a chain cover (4, 204, 304), a phase changing
mechanism (30), a selector valve (18), and an intermediate oil passage. The chain
cover (4, 204, 304) defines a valve chamber (12, 212, 312) having an inlet port (15b,
215b, 315b) for the hydraulic oil, an advancement port (15a, 215a, 315a), and a retardation
port (15c, 215c, 315c). The phase changing mechanism (30) is coupled to an end portion
of the camshaft (8 or 10) with the phase changing mechanism (30) being at least partially
covered by the chain cover (4, 204, 304). The phase changing mechanism (30) has a
plurality of hydraulic pressure chambers including an advancement chamber (38A) and
a retardation chamber (38B). The selector valve (18) is housed in the valve chamber
(12, 212, 312) of the chain cover (4, 204, 304), and configured and arranged to selectively
open the advancement port (15a, 215a, 315a) or the retardation port (15c, 215c, 315c).
The intermediate oil passage forming member (50, 150, 250, 350) is for conveying the
hydraulic oil in the valve chamber (12, 212, 312) of the chain cover (4, 204, 304)
from the advancement port (15a, 215a, 315a) of the valve chamber (12, 212, 312) to
the advancement chamber (38A) of the phase changing mechanism (30), and from the retardation
port (15c, 215c, 315c) of the valve chamber (12, 212, 312) to the retardation chamber
(38B) of the phase changing mechanism (30).
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