Valve timing control apparatus

Details Valve timing control apparatus Valve timing control apparatus

2002-10-10

2004-01-13

Denion, Thomas (Department: 3748)

Internal-combustion engines

Poppet valve operating mechanism

With means for varying timing

C123S090150, C123S090310

Reexamination Certificate

active

06675754

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to a valve timing control apparatus for variably controlling opening and closing timings of an engine valve, i.e., an intake valve and an exhaust valve, of an internal combustion engine depending on operating conditions of the engine.
Such a valve timing control apparatus is so designed as to control the opening and closing timings of the engine valve by varying a relative rotational phase of a crankshaft and a camshaft. The relative rotational phase of the crankshaft and the camshaft is adjusted by operating a phase adjustor. The phase adjustor is disposed between a drive rotary member operatively coupled with the crankshaft and a driven rotary member disposed on the camshaft side. Recently, there have been proposed various kinds of phase adjustors utilizing a gearing including a helical gear, a linkage or the like. The phase adjustor using the linkage is advantageous in lessening an axial length of the phase adjustor and reducing friction loss thereof.
Japanese Patent Application First Publication No. 2001-41013 discloses a valve timing control apparatus including such a phase adjustor using the linkage.
FIGS. 14 and 15
show the valve timing control apparatus of the related art. As illustrated in
FIGS. 14 and 15
, housing
101
as a drive rotary member is rotatably fitted onto an end portion of camshaft
102
. Housing
101
is drivably connected to an engine crankshaft via a timing chain. A plurality of followers
104
are slidably engaged in radial guide grooves
103
formed in an axial end surface of housing
101
. Lever shaft
106
as a driven rotary member is mounted to the end portion of camshaft
102
. A plurality of levers
105
radially outward projecting from lever shaft
106
are connected with the corresponding followers
104
via links
107
. Levers
105
and followers
104
are pivotally supported at opposite ends of links
107
, respectively. Intermediate rotary member
109
is disposed in opposed relation to the axial end surface of housing
101
in which radial guide grooves,
103
are formed, and supported on inner support rod
113
so as to be rotatable relative to housing
101
and lever shaft
106
. Intermediate rotary member
109
has spiral guide groove
108
in the end surface opposed to radial guide grooves
103
. A plurality of arcuate projections
110
projecting from an axial end face of each of followers
104
are engaged with spiral guide groove
108
and guided therealong. When electromagnetic brake
112
is deenergized, intermediate rotary member
109
is biased by spring
111
to be urged toward an advanced rotational position. In this position, followers
104
are placed at the radially outer-most position in the respective radial guide grooves
103
, in which the relative rotational phase between housing
101
and camshaft
102
is held most retarded or most advanced. Further, when electromagnetic brake
112
is energized, intermediate rotary member
109
is decelerated by the action of electromagnetic brake
112
toward a retarded rotational position. In this position, followers
104
are moved to the radially inner position, so that the relative rotational phase between housing
101
and camshaft
102
is held most advanced or most retarded. Lubricating oil supply passage
120
extends along camshaft
102
and is open to an axial end face of camshaft
102
. Lubricating oil is supplied to links
107
and mutually engaging portions of followers
104
and spiral guide grooves
108
via lubricating oil supply passage
120
.
SUMMARY OF THE INVENTION
In such a valve timing control apparatus as described above, the lubricating oil flows outside from the clearance between housing
101
and intermediate rotary member
109
so that links
107
and the mutually engaging portions of followers
104
and spiral guide grooves
108
are not always immersed in the lubricating oil. Therefore, there is a demand to ensure sufficient lubrication at links
107
and the mutually engaging portions of followers
104
and spiral guide grooves
108
. In addition, slight clearances are formed between the pivotal connections of links
107
to levers
105
and between the mutually engaging portions of followers
104
and spiral guide grooves
108
for the purpose of obtaining smooth motions thereof. There is a demand to prevent occurrence of vibration and noise at the slight clearances.
In one aspect of the present invention, there is provided a valve timing control apparatus for an internal combustion engine, comprising:
a drive rotary member adapted to be rotatively coupled with the engine;
a driven rotary member rotatably coupled with the drive rotary member;
an intermediate rotary member arranged to be rotatable relative to the drive rotary member and the driven rotary member;
a radial guide extending on one of the drive rotary member and the driven rotary member in a radial direction thereof;
a spiral guide disposed on the intermediate rotary member in an opposed relation to the radial guide;
a follower moveably engaged with the radial guide and the spiral guide;
a link coupling the follower with a radially outer periphery of the other of the drive rotary member and the driven rotary member, the link comprising one end pivotally connected with the radially outer periphery of the other of the drive rotary member and the driven rotary member and an opposite end pivotally connected with the follower;
an actuator operative to rotate the intermediate rotary member so as to allow a movement of the follower along the radial guide which is converted into relative rotation of the drive rotary member and the driven rotary member via the link; and
a lubricating oil chamber arranged to surround an engagement portion between the spiral guide and the follower and pivotal connection portions between the one end of the link and the radially outer periphery of the other of the drive rotary member and the driven rotary member and between the opposite end of the link and the follower, the lubricating oil chamber being adapted to be filled with lubricating oil.
In a further aspect of the present invention, there is provided a valve timing control apparatus for an internal combustion engine, comprising:
a drive rotary member adapted to be rotatively coupled with the engine;
a driven rotary member rotatably coupled with the drive rotary member;
an intermediate rotary member arranged to be rotatable relative to the drive rotary member and the driven rotary member;
a radial guide extending on one of the drive rotary member and the driven rotary member in a radial direction thereof;
a spiral guide disposed on the intermediate rotary member in an opposed relation to the radial guide;
a follower moveably engaged with the radial guide and the spiral guide;
a link coupling the follower with a radially outer periphery of the other of the drive rotary member and the driven rotary member, the link comprising one end pivotally connected with the radially outer periphery of the other of the drive rotary member and the driven rotary member and an opposite end pivotally connected with the follower;
an actuator operative to rotate the intermediate rotary member so as to allow a movement of the follower along the radial guide which is converted into relative rotation of the drive rotary member and the driven rotary member via the link; and
a lubricating oil chamber arranged to surround an engagement portion between the spiral guide and the follower and pivotal connection portions between the one end of the link and the radially outer periphery of the other of the drive rotary member and the driven rotary member and between the opposite end of the link and the follower, the lubricating oil chamber being adapted to be filled with lubricating oil and supplied with an amount of lubricating oil larger than an amount of lubricating oil leaking therefrom.
In a still further aspect of the present invention, there is provided a valve timing control apparatus for an internal combustion engine, comprising:
a drive rotary member adapted to be rotatively

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