U.S. patent application number 15/490361 was filed with the patent office on 2017-10-19 for valve opening/closing timing control apparatus.
This patent application is currently assigned to AISIN SEIKI KABUSHIKI KAISHA. The applicant listed for this patent is AISIN SEIKI KABUSHIKI KAISHA. Invention is credited to Hiroyuki AMANO, Takashi IWAYA, Masaki KOBAYASHI, Hiromitsu SHIGYO, Shigehiro TANABE, Kazuo UEDA.
Application Number | 20170298788 15/490361 |
Document ID | / |
Family ID | 60037970 |
Filed Date | 2017-10-19 |
United States Patent
Application |
20170298788 |
Kind Code |
A1 |
AMANO; Hiroyuki ; et
al. |
October 19, 2017 |
VALVE OPENING/CLOSING TIMING CONTROL APPARATUS
Abstract
A valve opening/closing timing control apparatus includes: a
driving side rotating body rotating synchronously with a crankshaft
of an internal combustion engine; a driven side rotating body
included in the driving side rotating body and rotating integrally
with a camshaft on a same axis as a rotation axis of the driving
side rotating body; a hydraulic fluid control mechanism displacing
a relative rotation phase between the driving side rotating body
and the driven side rotating body by supplying a hydraulic fluid to
one of an advance angle chamber and a retardation angle chamber; a
lock mechanism; and first and second unlocking flow paths
configured to communicate with the first pressure receiving
surface. The lock mechanism includes a lock member including an
engaging portion, a main body portion, and a first pressure
receiving surface a biasing member, and a lock recess.
Inventors: |
AMANO; Hiroyuki;
(Kariya-shi, JP) ; IWAYA; Takashi; (Obu-shi,
JP) ; TANABE; Shigehiro; (Kariya-shi, JP) ;
SHIGYO; Hiromitsu; (Toyota-shi, JP) ; KOBAYASHI;
Masaki; (Okazaki-shi, JP) ; UEDA; Kazuo;
(Gamagori-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AISIN SEIKI KABUSHIKI KAISHA |
Kariya-shi |
|
JP |
|
|
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi
JP
|
Family ID: |
60037970 |
Appl. No.: |
15/490361 |
Filed: |
April 18, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01L 2001/34423
20130101; F01L 2001/34476 20130101; F01L 1/3442 20130101; F01L
2001/34469 20130101; F01L 2250/02 20130101; F01L 2800/00 20130101;
F01L 2001/34466 20130101 |
International
Class: |
F01L 1/344 20060101
F01L001/344; F01L 1/356 20060101 F01L001/356 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2016 |
JP |
2016-083684 |
Jan 31, 2017 |
JP |
2017-015688 |
Claims
1. A valve opening/closing timing control apparatus comprising: a
driving side rotating body configured to rotate synchronously with
a crankshaft of an internal combustion engine; a driven side
rotating body included in the driving side rotating body and
configured to rotate integrally with a camshaft for opening or
closing of a valve of the internal combustion engine on a same axis
as a rotation axis of the driving side rotating body; a hydraulic
fluid control mechanism configured to displace a relative rotation
phase between the driving side rotating body and the driven side
rotating body by supplying a hydraulic fluid to one of an advance
angle chamber and a retardation angle chamber, which are defined
between the driving side rotating body and the driven side rotating
body; a lock mechanism including a lock member slidably inserted
into a guide hole formed in one of the driving side rotating body
and the driven side rotating body, and including an engaging
portion, a main body portion having a larger diameter than that of
the engaging portion, and a first pressure receiving surface formed
in an annular shape on an end surface of the main body portion at
an intermediate position between the engaging portion and the main
body portion, a biasing member configured to bias the lock member
in a direction where the engaging portion on one end side of the
lock member protrudes, and a lock recess formed in a remaining one
of the driving side rotating body and the driven side rotating body
so as to allow the engaging portion to be fitted thereinto; a first
unlocking flow path configured to communicate with the first
pressure receiving surface when the engaging portion is moved from
a locking position where the engaging portion is fitted into the
lock recess to a position at which the engaging portion is farther
spaced apart from the lock recess than at a locking boundary
position where the engaging portion is separated from the lock
recess; and a second unlocking flow path configured to communicate
with the first pressure receiving surface when the engaging portion
is at an unlocking position where the engaging portion is farther
spaced apart from the lock recess than at the locking boundary
position, and to be in non-communication state with the first
pressure receiving surface as a flow path is closed by the main
body portion when the engaging portion is at the locking boundary
position.
2. The valve opening/closing timing control apparatus according to
claim 1, wherein the lock recess includes a fittable region that
extends in a displacement direction to enable displacement of the
relative rotation phase in a state where the engaging portion is
fitted into the lock recess, and a phase in which the engaging
portion is fitted into one side end of the fittable region of the
lock recess in the displacement direction is set to a locking
phase, wherein a range of the fittable region under influence of
the set locking phase is set to a sequence region, and in the
sequence region, a drain flow path configured to discharge the
hydraulic fluid communicates with the first unlocking flow path,
and an unlocking phase is set to be opposite to the locking phase
on the basis of the sequence region in the fittable region, and in
the unlocking phase, the first unlocking flow path and the drain
flow path are in non-communication state with each other in a state
where the engaging portion is fitted into the lock recess, and
supply of the hydraulic fluid to the first unlocking flow path and
the second unlocking flow path is enabled.
3. The valve opening/closing timing control apparatus according to
claim 2, further comprising: a phase sensor configured to detect
the relative rotation phase; and a lock shifting control unit
configured to: start a first phase control so as to displace the
relative rotation phase from a predetermined phase, which is
opposite to the locking phase on the basis of the sequence region,
to the locking phase; stop the displacement by the first phase
control at a time when the phase sensor detects that the relative
rotation phase exceeds the locking phase from the predetermined
phase; start a second phase control so as to displace the relative
rotation phase in a direction opposite to that in the first phase
control; stop the displacement by the second phase control at a
time when the phase sensor detects that the relative rotation phase
reaches a predetermined phase in the sequence region; and then
start a third phase control so as to displace the relative rotation
phase toward the locking phase.
4. The valve opening/closing timing control apparatus according to
claim 3, wherein, in the second phase control, when the relative
rotation phase reaches the sequence region and the displacement is
stopped, the stop is continued for a set time.
5. The valve opening/closing timing control apparatus according to
claim 4, wherein a control form of the lock shifting control unit
is set: to start a fourth phase control to stop the displacement
when the phase sensor detects that the relative rotation phase
exceeds the locking phase and is displaced to a predetermined phase
after the third phase control, and thereafter displace the relative
rotation phase in the same direction as the second phase control;
to stop the fourth phase control at a time when the phase sensor
detects that the relative rotation phase reaches a predetermined
phase in the sequence region; to maintain the stopped state for a
longer time than the set time; and then to perform a fifth phase
control to displace the relative rotation phase toward the locking
phase.
6. The valve opening/closing timing control apparatus according to
claim 3, wherein an absolute value of a displacement speed in the
second phase control is set to a smaller value than an absolute
value of a displacement speed in the first phase control.
7. The valve opening/closing timing control apparatus according to
claim 3, wherein in the second phase control, the displacement
speed in the sequence region is reduced with respect to the
displacement speed before reaching the sequence region.
8. The valve opening/closing timing control apparatus according to
claim 3, wherein the lock shifting control unit performs a dither
control to alternately and repeatedly supply the fluid into the
advance angle chamber and the retardation angle chamber within a
set time when the phase sensor detects that the relative rotation
phase reaches the locking phase by the third phase control.
9. The valve opening/closing timing control apparatus according to
claim 5, wherein the lock shifting control unit performs a dither
control to alternately and repeatedly supply the fluid into the
advance angle chamber and the retardation angle chamber within a
set time when the phase sensor detects that the relative rotation
phase reaches the locking phase by the third phase control.
10. The valve opening/closing timing control apparatus according to
claim 2, wherein a locking assist flow path is formed to apply a
pressure of the hydraulic fluid to the lock member in an engagement
direction when the relative rotation phase is opposite to the
sequence region on the basis of the locking phase.
11. The valve opening/closing timing control apparatus according to
claim 2, further comprising: an auxiliary lock mechanism including
a lock body slidably inserted into a support hole portion formed in
one of the driving side rotating body and the driven side rotating
body, a biasing body configured to bias a regulation end on one end
side of the lock body so that the regulation end protrudes, and an
auxiliary lock recess formed in a remaining one of the driving side
rotating body and the driven side rotating body so that the
regulation end of the lock body is fitted into the auxiliary lock
recess by biasing force of the biasing body, wherein the auxiliary
lock recess is formed in a region extending along the displacement
direction of the relative rotation phase so that the displacement
of the relative rotation phase is enabled in a state where the
regulation end is fitted into the auxiliary lock recess, and in a
state where the relative rotation phase is in the locking phase,
the lock body is disposed at a position at which the lock body
inhibits the displacement of the relative rotation phase between
both ends of the auxiliary lock recess in the displacement
direction.
12. The valve opening/closing timing control apparatus according to
claim 3, wherein one of the driving side rotating body and the
driven side rotating body is configured as an inner rotor having
the guide hole formed therein, and a remaining one of the driving
side rotating body and the driven side rotating body is configured
as an outer rotor having a pair of plates for fitting of the inner
rotor therebetween, the lock recess being formed in one of the
plates, and a communication portion being formed in a remaining one
of the plates so as to enable communication between the guide hole
and an external space, as the relative rotation phase approaches
the locking phase in the sequence region, a flow path area of the
communication portion communicating with the external space is
reduced and a flow path area of the drain flow path communicating
with the first unlocking flow path is increased, and in the second
phase control, when the flow path area of the communication portion
and the flow path area of the drain flow path reach 20% or more of
that in a completely opened state, the displacement by the second
phase control stops.
13. The valve opening/closing timing control apparatus according to
claim 7, wherein the lock shifting control unit performs dither
control to alternately and repeatedly supply the fluid to the
advance angle chamber and the retardation angle chamber within a
set time when the phase sensor detects that the relative rotation
phase reaches the locking phase by the third phase control.
14. The valve opening/closing timing control apparatus according to
claim 9, wherein the set time of the dither control performed after
the fifth control is set to be longer than the set time of the
dither control performed after the third control.
15. The valve opening/closing timing control apparatus according to
claim 4, wherein, in the lock shifting control, a duration in which
the relative rotation phase reaches the sequence region and the
displacement is stopped is changed according to a hydraulic
pressure and a number of revolutions of the internal combustion
engine.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
U.S.C. .sctn.119 to Japanese Patent Application 2016-083684 and
Japanese Patent Application 2017-015688, filed on Apr. 19, 2016 and
Jan. 31, 2017, respectively, the entire contents of which are
incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a valve opening/closing timing
control apparatus that includes a driving side rotating body that
rotates synchronously with a crankshaft of an internal combustion
engine, a driven side rotating body that rotates integrally with a
camshaft for the opening or closing of a valve of the internal
combustion engine, and a lock mechanism that restrains the rotating
bodies in a predetermined relative rotation phase.
BACKGROUND DISCUSSION
[0003] As a valve opening/closing timing control apparatus
including a lock mechanism as described above, JP 2013-160095A
(Reference 1) discloses a technology that includes a driving side
rotating body (outer rotor) and a driven side rotating body (inner
rotor), and also includes a lock mechanism (an advance/retardation
mechanism) having a lock pin and a fitting recess so as to regulate
such relative rotation phase.
[0004] In this reference 1, a lock spring is provided to apply
pressure to the lock pin in a protruding direction. The lock pin
includes a first pressure receiving surface that is formed on an
end of the lock pin to cause hydraulic pressure to act on the lock
pin in a retracting direction, a second pressure receiving surface
that is formed in an annular shape on an intermediate portion of
the lock pin to cause hydraulic pressure to act on the lock pin in
the retracting direction, and a biasing pressure receiving surface
that causes hydraulic pressure to act on the lock pin in the
protruding direction.
[0005] In this configuration, at the time of unlocking, the lock
pin is extracted from the fitting recess by causing the hydraulic
pressure of hydraulic oil in an independent unlocking flow path,
which is branched from an advance angle flow path, to act on the
first pressure receiving surface and the second pressure receiving
surface. On the contrary, when switching the lock pin to a locked
state, the lock pin is fitted into the fitting recess by causing
the hydraulic pressure of the hydraulic oil in a locking flow path,
which is branched from a retardation angle flow path, to
independently act on the biasing pressure receiving surfaces.
[0006] In addition, JP 2013-019278A (Reference 2) discloses a
technology that includes a driving side rotating body (outer
rotor), a driven side rotating body (inner rotor), and a lock
mechanism having a lock member and a lock recess to maintain these
rotating bodies in a locking phase, and also includes a regulation
mechanism having a regulation member and a regulation recess so as
to determine the range of displacement of the relative rotation
phase between the driving side rotating body and the driven side
rotating body.
[0007] In this reference 2, the lock member includes a first end
configured to be fitted into the lock recess by the biasing force
of a spring and a second end having a larger diameter than that of
the first end, and a first pressure receiving surface is formed at
the boundary position of the first and second ends. From this
configuration, when unlocking the lock member, a hydraulic fluid is
supplied to the first pressure receiving surface. In addition, the
regulation member includes a first end configured to be fitted into
the regulation recess by the biasing force of a spring and a fourth
end having a larger diameter than that of the first end, and a
first pressure receiving surface is formed at the position that is
successive to the fourth end. When releasing the regulation from
this configuration, the hydraulic fluid is supplied to the first
pressure receiving surface.
[0008] As described in Reference 1 or Reference 2, a configuration,
which includes a fitting end configured to be fitted into a lock
recess (the fitting recess in Reference 1), and a pressure
receiving surface having a larger diameter than that of the fitting
end such that unlocking is performed by supplying the hydraulic oil
to the pressure receiving surface is employed. In the case of
shifting to a locked state, the pressure of hydraulic fluid acting
on the pressure receiving surface is released so that the shifting
to the locked state is implemented by the biasing force of a
spring.
[0009] Specifically, the pressure in a flow path, which
communicates with the pressure receiving surface, is reduced to a
drain pressure by operating a control valve. However, for example,
considering the configuration of Reference 1, even when the
pressure in flow paths, which respectively communicate with the
first pressure receiving surface and the second pressure receiving
surface, is reduced, it is considered that time is required until
the pressure in the flow path communicating with the second
pressure receiving surface (the independent unlocking flow path in
Reference 1) is reduced, and slight time retardation is caused
until the lock member starts to operate. In addition, even when the
lock member starts to operate, it is considered that, since the
hydraulic fluid is discharged from the flow path communicating with
the second pressure receiving surface, the operating speed of the
lock member is reduced from the pressure acting upon discharge.
[0010] These problems are caused by the flow path resistance in the
flow path communicating with the second pressure receiving surface,
and there is room for improvement in consideration of rapid
shifting to the locked state.
[0011] Thus, a need exists for a valve opening/closing timing
control apparatus which is not susceptible to the drawback
mentioned above.
SUMMARY
[0012] A feature of an aspect of this disclosure resides in that a
valve opening/closing timing control apparatus includes: a driving
side rotating body configured to rotate synchronously with a
crankshaft of an internal combustion engine; a driven side rotating
body included in the driving side rotating body and configured to
rotate integrally with a camshaft for opening or closing of a valve
of the internal combustion engine on a same axis as a rotation axis
of the driving side rotating body; a hydraulic fluid control
mechanism configured to displace a relative rotation phase between
the driving side rotating body and the driven side rotating body by
supplying a hydraulic fluid to one of an advance angle chamber and
a retardation angle chamber, which are defined between the driving
side rotating body and the driven side rotating body; and a lock
mechanism including a lock member slidably inserted into a guide
hole formed in one of the driving side rotating body and the driven
side rotating body, a biasing member configured to bias the lock
member in a direction where an engaging portion on one end side of
the lock member protrudes, and a lock recess formed in a remaining
one of the driving side rotating body and the driven side rotating
body so as to allow the engaging portion to be fitted thereinto.
The lock member includes the engaging portion, a main body portion
having a larger diameter than that of the engaging portion, and a
first pressure receiving surface formed in an annular shape on an
end surface of the main body portion at an intermediate position
between the engaging portion and the main body portion. The valve
opening/closing timing control apparatus further includes: a first
unlocking flow path configured to communicate with the first
pressure receiving surface when the engaging portion is moved from
a locking position where the engaging portion is fitted into the
lock recess to a position at which the engaging portion is farther
spaced apart from the lock recess than at a locking boundary
position where the engaging portion is separated from the lock
recess; and a second unlocking flow path configured to communicate
with the first pressure receiving surface when the engaging portion
is at an unlocking position at which the engaging portion is
farther spaced apart from the lock recess than at the locking
boundary position, and to be in non-communication state with the
first pressure receiving surface as a flow path is closed by the
main body portion when the engaging portion is at the locking
boundary position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing and additional features and characteristics of
this disclosure will become more apparent from the following
detailed description considered with the reference to the
accompanying drawings, wherein:
[0014] FIG. 1 is a cross-sectional view of a valve opening/closing
timing control apparatus;
[0015] FIG. 2 is a cross-sectional view taken along line II-II of
FIG. 1;
[0016] FIG. 3 is a block circuit diagram of a control system;
[0017] FIG. 4 is an operational image diagram of a main lock
mechanism;
[0018] FIG. 5 is an operational image diagram of a lock unit in a
predetermined phase;
[0019] FIG. 6 is an operational image diagram of the lock unit,
which is displaced from the predetermined phase in a retardation
angle direction;
[0020] FIG. 7 is an operational image diagram of the lock unit,
which is further displaced from the predetermined phase in the
retardation angle direction;
[0021] FIG. 8 is an operational image diagram of the lock unit,
which reaches a first stop phase;
[0022] FIG. 9 is an operational image diagram of the lock unit,
which is displaced from the first stop phase in an advance angle
direction;
[0023] FIG. 10 is an operational image diagram of the lock unit,
which reaches a second stop phase;
[0024] FIG. 11 is an operational image diagram of the lock unit,
which reaches an intermediate locking phase;
[0025] FIG. 12 is a timing chart illustrating a phase displacement
in a lock shifting control;
[0026] FIG. 13 is a flowchart of a lock shifting control;
[0027] FIG. 14 is a flowchart of a retry control routine;
[0028] FIG. 15 is an Image diagram of a main lock mechanism, which
is in the second stop phase;
[0029] FIG. 16 is a chart illustrating variation in the area of a
flow path, such as, for example, a drain flow path or a
communication portion;
[0030] FIG. 17 is an image diagram of the main lock mechanism,
which is in a first comparative phase Qf;
[0031] FIG. 18 is an image diagram of the main lock mechanism,
which is in a second comparative phase Qn;
[0032] FIG. 19 is a flowchart of a lock shifting control according
to an additional embodiment (a);
[0033] FIG. 20 is a timing chart illustrating a phase displacement
according to the additional embodiment (a);
[0034] FIG. 21 is an image diagram of the main lock mechanism,
which is in the intermediate locking phase, according to an
additional embodiment (b);
[0035] FIG. 22 is a timing chart illustrating a phase displacement
according to the additional embodiment (b); and
[0036] FIG. 23 is a flowchart of a lock shifting control according
to the additional embodiment (b).
DETAILED DESCRIPTION
[0037] Hereinafter, the embodiment of the present invention will be
described with reference to the drawings.
[Basic Configuration]
[0038] As illustrated in FIGS. 1 and 2, a valve opening/closing
timing control apparatus A includes an outer rotor 20 as a driving
side rotating body, an inner rotor 30 as a driven side rotating
body, and an electromagnetic control valve 40 as a hydraulic fluid
control mechanism that controls hydraulic oil as a hydraulic
fluid.
[0039] The valve opening/closing timing control apparatus A is
disposed coaxially with the rotation axis X of an intake camshaft 5
of an engine E as an internal combustion engine, and is provided
with an advance angle chamber Ca and a retardation angle chamber Cb
between the outer rotor 20 (driving side rotating body) and the
inner rotor 30 (driven side rotating body). By supplying the
hydraulic oil (hydraulic fluid) to one of the advance angle chamber
Ca and the retardation angle chamber Cb under the control of the
electromagnetic control valve 40, the relative rotation phase
between the outer rotor 20 and the inner rotor 30 about the
rotation axis X (hereinafter, referred to as a "relative rotation
phase") is displaced, so that a change in the opening/closing
timing of an intake valve 5V is implemented.
[0040] The valve opening/closing timing control apparatus A
includes a lock unit LU that maintains the relative rotation phase
in an intermediate locking phase M illustrated in FIG. 2. The lock
unit LU includes a main lock mechanism Lm and an auxiliary lock
mechanism Ls. When these mechanisms simultaneously reach a locked
state, the relative rotation phase is maintained in the
intermediate locking phase M.
[0041] In particular, the intermediate locking phase M is to set
the intake valve 5V to the opening/closing timing that is suitable
for starting the engine E. Therefore, when an artificial operation
is performed to stop the engine E, prior to stopping the engine E,
a control unit 90 illustrated in FIG. 3 performs a control to
displace the relative rotation phase to the intermediate locking
phase M and to set the lock unit LU to the locked state.
[Engine]
[0042] The engine E (an example of an internal combustion engine)
of FIG. 1 is illustrated as being provided in a vehicle such as a
passenger car, and includes a crankshaft 1 in the lower portion of
the engine E. In addition, pistons 3 are accommodated inside
cylinder bores of a cylinder block 2, which is provided at the
upper position of the engine E, and the pistons 3 are connected to
the crankshaft 1 by connecting rods 4, respectively. In the upper
portion of the engine E, the intake camshaft 5 configured to open
or close the intake valves 5V and an exhaust camshaft (not
illustrated) are provided.
[0043] In an engine constituent member 10 that rotatably supports
the intake camshaft 5, a supply flow path 8 is formed to be
supplied with the hydraulic oil from a hydraulic pump P driven by
the engine E. The hydraulic pump P supplies lubricating oil as the
hydraulic oil, which is stored in an oil pan of the engine E, to
the electromagnetic control valve 40 via the supply flow path
8.
[0044] A timing chain 7 is wound around an output sprocket 6, which
is formed on the crankshaft 1 of the engine E, and a timing
sprocket 22S of the outer rotor 20. In addition, a sprocket is
provided on the front end of an exhaust camshaft on the exhaust
side, and the timing chain 7 is also wound around the sprocket.
[Valve Opening/Closing Timing Control Apparatus]
[0045] As illustrated in FIGS. 1 and 2, the valve opening/closing
timing control apparatus A rotates synchronously with the
crankshaft 1 because the timing chain 7 is wound around the timing
sprocket 22S of the outer rotor 20. In addition, the inner rotor 30
rotates integrally with the intake camshaft 5 because the inner
rotor 30 is connected to the intake camshaft 5 by a connecting bolt
50.
[0046] In the valve opening/closing timing control apparatus A, as
illustrated in FIG. 2, the entire apparatus rotates in a driving
rotation direction S. The direction in which the inner rotor 30
rotates relative to the outer rotor 20 in the same direction as the
driving rotation direction S is referred to as an advance angle
direction Sa, and the opposite direction is referred to as a
retardation angle direction Sb. In addition, the opening/closing
timing of the intake valve 5V becomes faster by displacement in the
advance angle direction Sa, and the opening/closing timing of the
intake valve 5V becomes slower by displacement in the retardation
angle direction Sb.
[0047] In addition, although this embodiment illustrates the valve
opening/closing timing control apparatus A provided on the intake
camshaft 5, the valve opening/closing timing control apparatus A
may be provided on the exhaust camshaft, or may be provided on both
the intake camshaft 5 and the exhaust camshaft.
[0048] The outer rotor 20 includes an outer rotor main body 21, a
front plate 22, and a rear plate 23, which are fastened to each
other by plural fastening bolts 24. The above-described timing
sprocket 22S is formed on the outer circumference of the front
plate 22. Plurality of (three) protrusions 21T are integrally
formed on the inner circumference of the outer rotor main body 21
to protrude inward in a diametric direction.
[0049] The inner rotor 30 includes an inner rotor main body 31,
which has a cylindrical shape and is in close contact with the
protrusions 21T of the outer rotor main body 21, and plural (three)
vane portions 32, which protrudes outward in the diametric
direction from the outer circumference of the inner rotor main body
31 to come into contact with the inner circumferential surface of
the outer rotor main body 21.
[0050] An intermediate member 9 is disposed on the inner
circumference of the front plate 22. When a bolt head portion 52 of
the connecting bolt 50 is pressed against the intermediate member
9, the intermediate member 9, the inner rotor main body 31, and the
intake camshaft 5 are integrated to each other.
[0051] In this way, because the inner rotor 30 is included in the
outer rotor 20, plural (three) fluid pressure chambers C are formed
on the outer circumferential side of the inner rotor main body 31
at the intermediate positions between the adjacent protrusions 21T
in a rotational direction. Each of the fluid pressure chambers C is
divided into an advance angle chamber Ca and a retardation angle
chamber Cb by a vane portion 32. The inner rotor 30 is provided
with plural (three) advance angle flow paths 33, each of which
communicates with an advance angle chamber Ca, and plural (three)
retardation angle flow paths 34, each of which communicates with a
retardation angle chamber Cb.
[0052] As illustrated in FIG. 1, a torsion spring 28 is provided
over the outer rotor 20 and the intermediate member 9 so as to
assist the displacement of the relative rotation phase in the
advance angle direction Sa by applying a biasing force in the
advance angle direction Sa from the maximum retardation angle
phase.
[Valve Opening/Closing Timing Control Apparatus: Connecting
Bolt]
[0053] As illustrated in FIG. 1, the connecting bolt 50 includes a
bolt main body 51, a portion of which has a cylindrical shape, a
bolt head portion 52 on the outer end thereof, and a male screw
portion 53 on the inner end thereof.
[0054] Inside the intake camshaft 5, a shaft inner space 5T in
which a portion of the connecting bolt 50 is closely fitted is
formed, and a female screw portion to which the male screw portion
53 of the connecting bolt 50 is screwed is formed. The shaft inner
space 5T communicates with the above-described supply flow path 8,
and the hydraulic oil from the hydraulic pump P is supplied into
the shaft inner space 5T.
[0055] Inside the bolt main body 51, a spool chamber having a
cylinder inner surface shape is coaxially formed with the rotation
axis X from the bolt head portion 52 toward the male screw portion
53, and a spool 41 is accommodated in the spool chamber to be
movable in the direction along the rotation axis X. The outer end
side (in the direction of the bolt head portion 52) of the spool 41
is configured to protrude outward by the biasing force of a spool
spring. In addition, a land portion is formed on the outer
circumference of the spool 41 to control the flow of the hydraulic
oil, and a drain hole 41 D is formed in the protruding side end to
discharge the hydraulic oil.
[0056] The bolt main body 51 is provided with a flow path, through
which the hydraulic oil is supplied from the shaft inner space 5T
to the spool 41, and a flow path, through which the hydraulic oil
is supplied to or discharged from the advance angle flow path 33
and the retardation angle flow path 34 according to the operation
of the spool 41.
[Electromagnetic Control Valve]
[0057] As described above, the electromagnetic control valve 40
includes a spool 41 and an electromagnetic solenoid 44. The
electromagnetic solenoid 44 includes a plunger 44a, the protruding
amount of which is controlled by electric power supplied
thereto.
[0058] The spool 41 is provided, on the outer end side, with an
abutment surface, on which the plunger 44a is abutted. By
controlling the protruding amount of the plunger 44a, the spool 41
is set to an advance angle position illustrated in FIG. 1, a
neutral position at which the spool 41 is more press-fitted by a
predetermined amount than at the advance angle position, and a
retardation angle position at which the spool 41 is more
press-fitted than at the neutral position.
[0059] In addition, when the spool 41 is set to the neutral
position, the advance angle flow path 33 and the retardation angle
flow path 34 are closed. As a result, no hydraulic fluid is
supplied to or discharged from the advance angle chamber Ca and the
retardation angle chamber Cb, and the relative rotation phase is
maintained.
[0060] In addition, when the spool 41 is set to the advance angle
position, the hydraulic oil is supplied to the advance angle flow
path 33, and at the same time, the hydraulic oil is discharged from
the retardation angle flow path 34 through the drain hole 41D in
the spool 41. Thereby, the relative rotation phase is displaced in
the advance angle direction Sa.
[0061] In addition, when the spool 41 is set to the retardation
angle position, the hydraulic oil is supplied to the retardation
angle flow path 34, and at the same time, the hydraulic oil is
discharged from the advance angle flow path 33 through the drain
hole 41D in the spool 41. Thereby, the relative rotation phase is
displaced in the retardation angle direction Sb.
[Valve Opening/Closing Timing Control Apparatus: Main Lock
Mechanism]
[0062] As illustrated in FIGS. 1, 2, and 4 to 11, the main lock
mechanism Lm includes a lock member 71 slidably inserted into a
guide hole 70, which is formed in one of the vane portions 32 in
the attitude parallel with the rotation axis X, a main lock recess
72 formed in the rear plate 23 so as to allow an engaging portion
71b of the lock member 71 to be engaged therein, and a main lock
spring 73 as a biasing member that obtains the biasing force
required to cause the engaging portion 71b to be engaged in the
main lock recess 72. The guide hole 70 includes a large-diameter
guide hole portion 70a and a small-diameter guide hole portion 70b
having a smaller diameter than that of the large-diameter guide
hole portion 70a.
[0063] Although the entire lock member 71 has a cylindrical shape,
the lock member 71 includes a main body portion 71a that is
slidably accommodated in the large-diameter guide hole portion 70a
of the guide hole 70, the engaging portion 71b that has a smaller
diameter than that of the main body portion 71a and is slidably
accommodated in the small-diameter guide hole portion 70b, and a
shaft-shaped portion 71c that is provided at the intermediate
position therebetween and has a smaller diameter than that of the
engaging portion 71b.
[0064] The lock member 71 includes a first pressure receiving
surface U1 formed on the end surface of the main body portion 71a
at the intermediate position between the main body portion 71a and
the engaging portion 71b, and a second pressure receiving surface
U2 formed on the protruding side end of the engaging portion
71b.
[0065] The main lock recess 72 is formed in a groove shape to
extend along the displacement direction of the relative rotation
phase. Specifically, the main lock recess 72 is formed in an
arc-shaped region about the rotation axis X and has a slightly
greater width than the diameter of the engaging portion 71b.
Thereby, the engaging portion 71b enables the displacement of the
relative rotation phase within the range of a fittable region along
the direction in which the main lock recess 72 is formed, in a
state of being fitted into the main lock recess 72.
[0066] The main lock spring 73 is configured in the form of a
compression coil spring, which is disposed between the end surface
of the main body portion 71a on the opposite side of the engaging
portion 71b and the front plate 22.
[0067] The vane portion 32 having the guide hole 70 formed therein
is provided with a first unlocking flow path 75 that communicates
with the small-diameter guide hole portion 70b and a second
unlocking flow path 76 that communicates with the large-diameter
guide hole portion 70a.
[0068] The first unlocking flow path 75 communicates with the first
pressure receiving surface U1 when the engaging portion 71b is
moved from a locking position J1 at which the engaging portion 71b
is completely fitted into the main lock recess 72 as illustrated in
FIGS. 5, 10, and 11 to the position at which the engaging portion
71b is farther spaced apart from the main lock recess 72 than at a
locking boundary position J2, which corresponds to the position
immediately after the engaging portion 71b is extracted from the
main lock recess 72 as illustrated in FIG. 9.
[0069] In particular, when the engaging portion 71b is in a region
extending from the locking position J1 to the locking boundary
position J2, the second unlocking flow path 76 is closed by the
main body portion 71a and is in non-communication with the first
pressure receiving surface U1.
[0070] In addition, when the engaging portion 71b is farther spaced
apart from the main lock recess 72 than at the locking boundary
position J2 to thereby be at an unlocking position J3 illustrated
in FIGS. 7 and 8, the first unlocking flow path 75 communicates
with the second pressure receiving surface U2.
[0071] In addition, when the engaging portion 71b is farther spaced
apart from the main lock recess 72 than at the locking boundary
position J2 to thereby be at the unlocking position J3 illustrated
in FIGS. 7 and 8, the second unlocking flow path 76 communicates
with the first pressure receiving surface U1.
[0072] The first unlocking flow path 75 communicates with a first
control port 75a, which is open toward the inner surface of the
rear plate 23, and also communicates with a first retardation angle
port 75b at the position spaced apart from the guide hole 70. In
addition, when the relative rotation phase is displaced from the
intermediate locking phase M illustrated in FIGS. 2 and 11 to the
region that is included in a sequence region G (see FIG. 12)
illustrated in FIGS. 9 and 10, the first control port 75a
communicates with a drain flow path 23D, which is drilled in the
rear plate 23. Although the first control port 75a and the first
retardation angle port 75b are formed in the positional
relationship illustrated in FIG. 2, for easy understanding, a
detailed configuration is not illustrated in FIGS. 4 to 11.
[0073] In addition, as illustrated in FIGS. 5 and 6, when the
relative rotation phase is in an unlocking phase in which the
relative rotation phase is farther displaced than the sequence
region G (see FIG. 12) in the advance angle direction Sa, the first
retardation angle port 75b communicates with a first retardation
angle side groove 23R, which is formed in the rear plate 23.
[0074] The drain flow path 23D communicates with an external space
of the rear plate 23 and the first unlocking flow path 75 so that
the hydraulic oil is discharged, which greatly reduces the pressure
acting on the first pressure receiving surface U1. In addition, the
first retardation angle side groove 23R communicates with the
retardation angle chamber Cb and the first retardation angle port
75b so that the hydraulic oil is supplied from the retardation
angle chamber Cb to the first pressure receiving surface U1.
[0075] The second unlocking flow path 76 is configured such that,
when the hydraulic oil is supplied to the retardation angle flow
path 34, the hydraulic oil having the same pressure as in the
retardation angle flow path 34 is supplied to the second unlocking
flow path 76. From this configuration, only when the lock member 71
is at the unlocking position J3 illustrated in FIG. 7, the
hydraulic oil is supplied from the second unlocking flow path 76 to
the first pressure receiving surface U1.
[0076] In addition, as a configuration that supplies the hydraulic
oil to the second unlocking flow path 76, a flow path configuration
that makes the second unlocking flow path 76 communicate with the
retardation angle flow path 34 or makes the second unlocking flow
path 76 communicate with the retardation angle chamber Cb may be
adopted.
[0077] As illustrated in FIG. 8, a locking assist flow path 22A is
formed in a groove shape in the inner surface of the front plate 22
so as to communicate with an opening portion of the large-diameter
guide hole portion 70a when the relative rotation phase is
displaced closer to the retardation angle side than the
intermediate locking phase M. Although the locking assist flow path
22A, as illustrated in FIG. 2, communicates with an assist groove
32a formed in the vane portion 32 so that some of the hydraulic oil
is supplied to the large-diameter guide hole portion 70a, for easy
understanding, for example, FIGS. 4 to 11 illustrate the locking
assist flow path 22A as directly communicating with the
large-diameter guide hole portion 70a, and do not illustrate the
assist groove 32a.
[0078] Through the formation of the locking assist flow path 22A,
when the relative rotation phase is displaced from the phase
illustrated in FIG. 8 in the advance angle direction Sa, some of
the hydraulic oil supplied to the advance angle chamber Ca is
supplied to the large-diameter guide hole portion 70a to assist the
operation of the lock member 71 into the main lock recess 72.
[0079] In addition, as illustrated in FIGS. 4 to 7, a communication
portion 25 is formed in the front plate 22 to make the opening
portion of the large-diameter guide hole portion 70a communicate
with the external space when the relative rotation phase is
displaced in the advance angle direction from the intermediate
locking phase M. Although the communication portion 25, as
illustrated in FIG. 2, is configured as an opening that penetrates
the front plate 22 and communicates with the large-diameter guide
hole portion 70a through a communication groove 32b formed in the
vane portion 32, for example, FIGS. 4 to 11 illustrate the
communication portion 25 as having a groove shape, and do not
illustrate the communication groove 32b for easy understanding.
[0080] Through the formation of the communication portion 25,
outside air is suctioned into the large-diameter guide hole portion
70a when the engaging portion 71b of the lock member 71 is engaged
with the main lock recess 72, which reduces the influence of a
negative pressure, thereby allowing the operation of the lock
member 71 to be easily performed.
[Valve Opening/Closing Timing Control Apparatus: Auxiliary Lock
Mechanism]
[0081] As illustrated in FIG. 2, the auxiliary lock mechanism Ls
includes a lock body 81 slidably inserted into a support hole 80,
which is formed in one of the protrusions 21T of the outer rotor
main body 21 in the attitude along the radial direction about the
rotation axis X, an auxiliary lock recess 82 formed in the outer
circumference of the inner rotor main body 31 so as to allow a
regulation end 81a of the lock body 81 to be fitted thereinto, and
an auxiliary lock spring 83 as a biasing body that obtains the
biasing force required to cause the lock body 81 to be engaged with
the auxiliary lock recess 82. An auxiliary unlocking flow path 35
communicates with the auxiliary lock recess 82, and is supplied
with the hydraulic oil from the advance angle flow path 33.
[0082] The lock body 81 has a plate shape, and the protruding side
thereof is referred to as a regulation end 81a. In addition, the
lock body 81 may be configured to have a rod shape. The auxiliary
lock spring 83 is configured as a compression coil spring, which is
disposed between the end surface of the lock body 81 on the
opposite side of the regulation end 81a and the rear plate 23 to
exert the biasing force required to cause the regulation end 81a to
be engaged with the auxiliary lock recess 82.
[0083] The auxiliary lock recess 82 is formed in a concave shape to
extend along the displacement direction of the relative rotation
phase. Thereby, in a state where the regulation end 81a is fitted
into the auxiliary lock recess 82, the relative rotation phase may
be displaced in a predetermined region along the direction in which
the auxiliary lock recess 82 is formed.
[0084] As illustrated in FIG. 2, when the relative rotation phase
is in the intermediate locking phase M, the lock body 81 of the
auxiliary lock mechanism Ls is abutted on the end of the auxiliary
lock recess 82 in the retardation angle direction Sb, and the lock
member 71 of the main lock mechanism Lm is abutted on the end of
the main lock recess 72 in the advance angle direction Sa. Thereby,
the relative rotation phase is maintained in the intermediate
locking phase M.
[0085] In the valve opening/closing timing control apparatus A, as
described above, the displacement of the relative rotation phase is
implemented by the control of the hydraulic oil by the
electromagnetic control valve 40, and the shifting of the main lock
mechanism Lm and the auxiliary lock mechanism Ls to the locked
state is implemented by the control of the hydraulic oil by the
electromagnetic control valve 40.
[Control Configuration]
[0086] As illustrated in FIG. 3, the valve opening/closing timing
control apparatus A includes a control unit 90 that outputs a
control signal to the electromagnetic solenoid 44 of the
electromagnetic control valve 40. Detected signals from a phase
sensor N, which detects the relative rotation phase, and a
temperature sensor T, which detects the temperature of the engine E
(basically, the temperature of cooling water), are input to the
control unit 90.
[0087] In addition, although it is assumed that the phase sensor N
acquires the rotation angle of the crankshaft 1 and the rotation
angle of the inner rotor 30 at short intervals and detects the
relative rotation phase by calculation, the relative rotation phase
may be detected from the phase difference between the outer rotor
20 and the inner rotor 30.
[0088] The control unit 90 functions as an ECU that controls the
engine E. For example, at the time of performing a control to stop
the engine, the control unit 90 performs a control to shift the
relative rotation phase to the intermediate locking phase M, and
performs a control to stop the engine E after the lock unit LU
reaches the locked state. In particular, the control unit 90
includes a lock shifting controller 91 that implements the shifting
of the lock unit LU to the locked state, an unlocking controller 92
that implements the unlocking of the lock unit LU, and a phase
controller 93 that implements the displacement of the relative
rotation phase.
[0089] In addition, although the lock shifting controller 91, the
unlocking controller 92, and the phase controller 93 are configured
by software, but may be configured by hardware such as, for
example, logic, or may be partially configured by hardware.
[0090] In addition, in the following description, a control to
supply the hydraulic oil in a flow path system that displaces the
relative rotation phase in the advance angle direction Sa (e.g.,
the advance angle flow path 33 or the advance angle chamber Ca) is
referred to as an "advance angle operation." On the contrary, a
control to supply the hydraulic oil to a flow path system that
displaces the relative rotation phase in the retardation angle
direction Sb (e.g., the retardation angle flow path 34 or the
retardation angle chamber Cb) is referred to as a "retardation
angle operation."
[Shifting of Main Lock Mechanism to Locked State]
[0091] A lock shifting control will be described in which the lock
shifting controller 91 shifts the relative rotation phase to the
intermediate locking phase M, starting from a state where the
relative rotation phase is in a predetermined phase K (see FIGS. 5
and 12) in which the relative rotation phase is displaced from the
fittable region in the advance angle direction Sa.
[0092] As illustrated in the timing chart of FIG. 12 and the
flowchart of FIG. 13, in the lock shifting control, a first phase
control is started to displace the relative rotation phase toward
the intermediate locking phase M by the retardation angle
operation. By this first phase control, the displacement is stopped
at the time when the phase sensor N detects that the relative
rotation phase exceeds the intermediate locking phase M from the
predetermined phase K illustrated in FIG. 5 and reaches a first
stop phase Q1 (steps #101 to #103). In addition, the specific
example of the first phase control includes steps #101 to #103.
[0093] Since the hydraulic oil is supplied to the retardation angle
flow path 34 when the retardation angle operation is started in a
state where the relative rotation phase is in the predetermined
phase K (the timing V in FIG. 12), the lock member 71 reaches the
unlocking position J3 as illustrated in FIG. 7 after the lock
member 71 starts to operate in an unlocking direction as
illustrated in FIG. 6 by the pressure of the hydraulic oil acting
on the first pressure receiving surface U1 from the first unlocking
flow path 75.
[0094] When the relative rotation phase is displaced as illustrated
in FIGS. 5 to 7, the sequential timings vary in the order of V, VI,
and VII in FIG. 12. In addition, in a situation where the relative
rotation phase varies as described above, the lock body 81 is in an
unlocked state. Then, when the lock member 71 reaches the unlocking
position J3, since the second unlocking flow path 76 communicates
with the first pressure receiving surface U1, the first unlocking
flow path 75 communicates with the second pressure receiving
surface U2, and the pressure of the hydraulic oil acts thereon, the
lock member 71 is maintained at the unlocking position J3.
[0095] By continuing the retardation angle operation, the relative
rotation phase reaches the first stop phase Q1 illustrated in FIG.
8 in a state where the lock member 71 is maintained at the
unlocking position J3 (the timing VIII in FIG. 12). The lock body
81 is fitted into the auxiliary lock recess 82 when the relative
rotation phase reaches the first stop phase Q1.
[0096] When the relative rotation phase, which is closer to the
retardation angle side than the first stop phase Q1 and the
intermediate locking phase M, passes the intermediate locking phase
M in the course of reaching the first stop phase Q1, the first
control port 75a communicates with the drain flow path 23D.
However, since the lock member 71 is maintained at the unlocking
position J3 by the pressure of the hydraulic oil from the second
unlocking flow path 76, the engaging portion 71b of the lock member
71 is not fitted into the main lock recess 72.
[0097] Thereafter, a second phase control is started to displace
the relative rotation phase in the direction opposite to the first
phase control by the advance angle operation. Since, in the first
stop phase Q1, the locking assist flow path 22A communicates with
the opening portion of the large-diameter guide hole portion 70a as
illustrated in FIG. 8, the operation of the lock member 71 to the
main lock recess 72 is assisted by the pressure of the hydraulic
oil along with the displacement of the relative rotation phase in
the advance angle direction Sa.
[0098] After the relative rotation phase passes the phase
illustrated in FIG. 9 by this advance angle operation, as
illustrated in FIG. 10, the relative rotation phase reaches a
second stop phase Q2 that is included in the sequence region G. At
the time when the phase sensor N detects that the relative rotation
phase reaches the second stop phase Q2, the displacement is stopped
and the relative rotation phase waits (stops to operate and stands
by) for a first set time T1 (steps #104 to #106). In addition, the
steps #104 to #106 correspond to a specific example of the second
phase control.
[0099] The phases of FIGS. 9 and 10 appear at the timings IX and X
in FIG. 12. In addition. FIG. 12 illustrates a state where the
relative rotation phase waits for the first set time T1 after
reaching the second stop phase Q2. In addition, since the hydraulic
oil is supplied to the auxiliary unlocking flow path 35, the lock
body 81 is extracted from the auxiliary lock recess 82.
[0100] The first set time T1 is set to be longer as the temperature
detected by the temperature sensor T is lower. When waiting as
described above, the pressure in the retardation angle flow path 34
and the retardation angle chamber Cb is greatly reduced. In
addition, in the second stop phase Q2, as illustrated in FIGS. 10
and 15, a state where the opening portion of the large-diameter
guide hole portion 70a of the guide hole 70 communicates with the
drain flow path 230 through the first unlocking flow path 75 and a
state where the communication portion 25 causes the opening portion
of the large-diameter guide hole portion 70a of the guide hole 70
to communicate with the external space are continuously maintained.
Therefore, the pressure acting on the first pressure receiving
surface U1 and the second pressure receiving surface U2 is reduced,
and an operation of fitting the engaging portion 71b of the lock
member 71 into the main lock recess 72 by the biasing force of the
main lock spring 73 is performed.
[0101] In particular, in this second stop phase Q2, since the
second unlocking flow path 76 is closed by the main body portion
71a of the lock member 71, no hydraulic oil flows to the second
unlocking flow path 76, and there is no problem of reducing the
operation speed of the lock member 71 due to the flow path
resistance acting on the hydraulic oil in the second unlocking flow
path 76.
[0102] Thereafter, a third phase control is performed to displace
the relative rotation phase toward the intermediate locking phase M
by the retardation angle operation. The control terminates when the
relative rotation phase detected by the phase sensor N is stopped
at the intermediate locking phase M illustrated in FIG. 11 by the
retardation angle operation (steps #107 and #108).
[0103] The phase change at the time when the relative rotation
phase reaches the intermediate locking phase M as described above
is illustrated as the timing XI in FIG. 12. In the case where the
relative rotation phase detected by the phase sensor N is stopped
at the intermediate locking phase M by the above-described control,
the engaging portion 71b of the lock member 71 is fitted into the
main lock recess 72 prior to the stop, as illustrated in FIG. 10.
In this state, when the relative rotation phase is displaced in the
retardation angle direction Sb, the engaging portion 71b is abutted
on the end of the main lock recess 72 so that the relative rotation
is stopped.
[0104] At the timing when the relative rotation is stopped as
described above, the regulation end 81a of the lock body 81 of the
auxiliary lock mechanism Ls is shifted to a state where it is
fitted into the auxiliary lock recess 82. As a result, the relative
rotation phase of the valve opening/closing timing control
apparatus A is maintained at the intermediate locking phase M.
[0105] In particular, after the third phase control, when the phase
sensor N detects that the relative rotation phase detected by the
phase sensor N exceeds the intermediate locking phase M and is
displaced to the retardation angle side, a retry control (step
#200) is executed.
[0106] This retry control (step #200) is automatically executed
when it is determined that the relative rotation phase detected by
the phase sensor N exceeds the intermediate locking phase M and is
displaced to the retardation angle side. The retry control is set
as a sub-routine. That is, as illustrated in the timing chart of
FIG. 12 (the area indicated by the two-dot chain line) and the
flowchart of FIG. 14, fourth phase control is performed to stop the
displacement at the time when the phase sensor N detects that the
relative rotation phase reaches the first stop phase Q1 (steps #201
and #202).
[0107] In the fourth phase control, the advance angle operation is
performed so as to displace the relative rotation phase in the same
direction as the second phase control. The displacement by the
fourth phase control is stopped at the time when the phase sensor N
detects that the relative rotation phase reaches the second stop
phase Q2 that is included in the sequence region G and the relative
rotation phase waits for a second set time T2, which is longer than
the first set time T1 (steps #203 to #205).
[0108] When the stop state continues for a long time in the second
stop phase Q2 as described above, a state where the small-diameter
guide hole portion 70b communicates with the drain flow path 23D
via the first unlocking flow path 75 is maintained for a long time.
Therefore, the pressure in the small-diameter guide hole portion
70b is reduced so that it becomes possible to make an operation by
which the engaging portion 71b of the lock member 71 is fitted into
the main lock recess portion 72 by the biasing force of the main
lock spring 73.
[0109] Thereafter, the fifth phase control displaces the relative
rotation phase toward the intermediate locking phase M by
performing the retardation angle operation, and when the relative
rotation phase detected by the phase sensor N is stopped at the
intermediate locking phase M, the fifth phase control is terminated
(step #206).
[0110] In the retry control (step #200), when the stop of the
relative rotation phase is not performed at the intermediate
locking phase M, the steps #108 and #200 are repeatedly performed.
However, for example, when the number of repetition times reaches a
set number of times, a control form is conceivable in which the
lock shifting control is forcibly terminated, or error information
is output to terminate the control.
[0111] In particular, when the retry control (step #200) is
repeatedly performed, a control form may be set to extend the
waiting time to correspond to the number of repetition times.
[0112] In addition, in a situation where the relative rotation
phase is opposite to the predetermined phase K with the
intermediate locking phase M being interposed therebetween, a
control to start from the step #104 in the flowchart of FIG. 13 is
performed when the lock shifting control is executed.
[Setting of Second Stop Phase]
[0113] FIG. 15 illustrates, in an enlarged scale, a state of the
main lock mechanism Lm in the second stop phase Q2 set by the
control of the lock shifting controller 91. In the second stop
phase Q2, it is required to cause the engaging portion 71b of the
lock member 71 to be engaged with the main lock recess 72 as soon
as possible by the biasing force of the main lock spring 73. In
order to enable such an engagement, the second stop phase Q2 is set
such that the hydraulic oil is rapidly discharged from the drain
flow path 23D and outside air is rapidly suctioned from the
communicating portion 25.
[0114] In the chart of FIG. 16, on the basis of the intermediate
locking phase M indicated by "O" on the horizontal axis, in the
region on the retardation angle side (the left side in FIG. 16) and
in the sequence region G on the advance angle side (the right side
in FIG. 16), the equivalent diameters of respective flow paths
through which the hydraulic oil is supplied or discharged are
illustrated in graphs.
[0115] As illustrated in FIG. 16, in a situation where the relative
rotation phase is closer to the retardation angle side (the left
side in FIG. 16) than the intermediate locking phase M, the flow
path area (communication diameter) in the communication region
between the locking assist flow path 22A and the advance angle
chamber Ca is illustrated as advance angle chamber communication Da
in a graph. The flow path area is increased to a predetermined
value while the relative rotation phase approaches the intermediate
locking phase M, but becomes zero (completely closed) before the
relative rotation phase reaches the intermediate locking phase
M.
[0116] Likewise, in a situation where the relative rotation phase
is closer to the retardation angle side (the left side in FIG. 16)
than the intermediate locking phase M, the flow path area
(communication diameter) of the communication region between the
retardation angle chamber Cb and the main lock recess 72 is
illustrated as retardation angle chamber communication Db in a
graph. The flow path area is reduced while the relative rotation
phase approaches the intermediate locking phase M, and becomes zero
(completely closed) before the relative rotation phase reaches
intermediate locking phase M.
[0117] In addition, in a situation where the relative rotation
phase is closer to the sequence region G on the advance angle side
(the right side in FIG. 16) than the intermediate locking phase M,
the flow path area (communication diameter) of the communication
region between the external space and the communicating portion 25
is illustrated as atmosphere communication Dc in the graph. The
flow path area is zero (completely closed) in the intermediate
locking phase M, and is enlarged as gets farther away from the
intermediate locking phase M toward the advance angle side.
[0118] In addition, the flow path area (communication diameter) of
the communication region between the first unlocking flow path 75
and the drain flow path 23D is illustrated as drain communication
Dd in a graph. The flow path area becomes the largest when the
relative rotation phase is near the intermediate locking phase M
and is reduced as gets farther away from the intermediate locking
phase M at the advance angle side and the retardation angle
side.
[0119] Here, as illustrated in FIGS. 16 and 17, considering a
situation where the relative rotation phase is in a first
comparative phase Qf, which is far from the intermediate locking
phase M, in the sequence region G, as illustrated in FIG. 16, the
flow path area of the atmosphere communication Dc is close to the
maximum value, whereas the flow path area of the drain
communication Dd is close to the minimum value.
[0120] On the other hand, as illustrated in FIGS. 16 and 18,
considering a situation where the relative rotation phase is in a
second comparative phase Qn, which is close to the intermediate
locking phase M, in the sequence region G as illustrated in FIG.
16, the flow path area of the atmospheric communication Dc of the
communicating portion 25 is close to the minimum value, whereas the
flow path area of the drain communication Dd between the first
unlocking flow path 75 and the drain flow path 23D is close to the
maximum value.
[0121] In addition, in FIG. 16, in a case where the graph of the
atmospheric communication Dc and the graph of the drain
communication Dd intersect each other in the central region of the
sequence region G, and the relative rotation phase is present near
the central region, approximately the same amount of hydraulic oil
flows to the communicating portion 25 and the drain flow path
23D0.
[0122] In the central region, both the flow path area of the
atmosphere communication Dc and the flow path area of the drain
communication Dd exceed 20% of the maximum value thereof. In
addition, in a situation where approximately the same amount of
hydraulic oil flows to the communicating portion 25 and the drain
flow path 23D, when the lock member 71 is engaged with the main
lock recess 72, outside air is suctioned from the communicating
portion 25, and at the same time, the hydraulic oil is discharged
from the drain flow path 230, which enables the rapid operation of
the lock member 71.
[0123] For this reason, the region of the sequence region G, in
which both the flow path area of the atmosphere communication Dc
and the flow path area of the drain communication Dd exceed 20% of
the maximum value thereof, is set to the second stop phase Q2, so
that the engaging portion 71b of the lock member 71 is engaged with
the main lock recess 72 as soon as possible by the biasing force of
the main lock spring 73.
[Unlocking: Displacement in Advance Angle Direction]
[0124] In addition, as illustrated in FIG. 11, when the relative
rotation phase is displaced in the advance angle direction Sa
starting from a state where the relative rotation phase is
maintained in the intermediate locking phase M, the unlocking
controller 92 executes the advance angle operation. By this
control, some of the hydraulic oil supplied to the advance angle
flow path 33 is supplied to the auxiliary unlocking flow path
35.
[0125] In addition to this supply, the pressure in the auxiliary
lock recess 82 of the auxiliary lock mechanism Ls is increased, and
as illustrated in FIG. 5, the regulation end 81a of the lock body
81 is spaced apart from the auxiliary lock recess 82 to realize
unlocking. Thereafter, when the relative rotation phase is
displaced in the advance angle direction Sa, the phase controller
93 maintains the control of supplying the hydraulic oil to the
advance chamber Ca. As a result, as illustrated in FIG. 5, the main
lock mechanism Lm performs the displacement of the relative
rotation phase in a state where the engaging portion 71b is engaged
with the main lock recess 72 (within the range of the fittable
region), and the relative rotation phase may be set to an arbitrary
phase. [Unlocking: Displacement in Retardation Angle Direction]
[0126] On the contrary, as illustrated in FIG. 11, when the
relative rotation phase is displaced in the retardation angle
direction Sb starting from a state where the relative rotation
phase is maintained in the intermediate locking phase M, a control
is performed in the order in which the unlocking controller 92
displaces the relative rotation phase in the advance angle
direction Sa, and thereafter the phase controller 93 operates in
the retardation angle direction Sb.
[0127] That is, the auxiliary lock mechanism Ls is unlocked when
the unlocking controller 92 firstly executes the advance angle
operation, and the displacement is stopped when the relative
rotation phase exceeds the sequence region G and reaches the
unlocking phase illustrated in FIG. 5. In this phase, the first
retardation angle port 75b of the first unlocking flow path 75
communicates with the first retardation angle side groove 23R.
[0128] In this state, when the phase controller 93 performs a
control to supply the hydraulic oil to the retardation angle
chamber Cb, the lock member 71 starts to operate in the unlocking
direction as illustrated in FIG. 6, and then reaches the unlocking
position J3 as illustrated in FIG. 7. By continuing the control to
supply the hydraulic oil to the retardation angle chamber Cb, the
relative rotation phase exceeds the intermediate locking phase M in
a state where the lock member 71 is maintained at the unlocking
position J3, and the lock body 81 is fitted into the auxiliary lock
recess 82.
[0129] The displacement in the retardation angle direction Sb is
performed within a range in which the lock body 81 is displaceable
while being fitted into the auxiliary lock recess 82. In the same
manner as the above description, the first control port 75a
communicates with the drain flow path 23D in the course of reaching
the relative rotation phase, which is closer to the retardation
angle side than the intermediate locking phase M. However, since
the lock member 71 is maintained at the unlocking position J3 by
the pressure of the hydraulic oil from the second unlocking flow
path 76, the engaging portion 71b of the lock member 71 is not be
fitted into the main lock recess 72.
[Acting Effect of Embodiment]
[0130] In this embodiment, when the relative rotation phase is set
to the intermediate locking phase M, the main lock mechanism Lm and
the auxiliary lock mechanism Ls of the lock unit LU simultaneously
reach the locked state, thereby maintaining the intermediate
locking phase M. In addition, the displacement of the relative
rotation phase in the advance angle direction Sa is implemented by
supplying the hydraulic oil to the advance angle flow path 33 and
the auxiliary unlocking flow path 35. In addition, when the
displacement of the relative rotation phase in the retardation
angle direction Sb is performed, the displacement is implemented by
firstly displacing the relative rotation phase in the advance angle
direction Sa, and then displacing the relative rotation phase in
the retardation angle direction Sb. Accordingly, there is provided
a configuration that does not require a dedicated control valve for
unlocking.
[0131] In order to implement such a control, the main lock recess
72 of the main lock mechanism Lm is formed in a groove shape to
extend in the peripheral direction, and the auxiliary lock recess
82 of the auxiliary lock mechanism Ls is also formed in a groove
shape to extend in the peripheral direction.
[0132] Accordingly, when the relative rotation phase is maintained
in the sequence region G, the hydraulic oil is discharged from the
first unlocking flow path 75 to the drain flow path 23D, thereby
enabling the shifting of the main lock mechanism Lm to the locked
state.
[0133] In particular, when the first unlocking flow path 75 and the
second unlocking flow path 76 are provided in order to control the
operation of the lock member 71 of the main lock mechanism Lm, and
the engaging portion 71b of the lock member 71 is located at the
locking position J1 or the locking boundary position J2, the
operation of the lock member 71 toward the locking position J1 can
be rapidly performed so as to enable reliable locking by limiting
the supply and discharge of the hydraulic oil in the second
unlocking flow path 76.
Additional Embodiment
[0134] This disclosure may be configured in the following manner,
in addition to the above-described embodiment (elements having the
same functions as those in the above-described embodiment will be
designated by the same reference numerals and symbols as those in
the above-described embodiment).
[0135] (a) The lock shifting control illustrated in FIGS. 19 and 20
is basically the same as the lock shifting control described in the
above-described embodiment, and has a difference in that, after the
relative rotation phase reaches the first stop phase Q1 by first
phase control, the displacement speed is reduced until the relative
rotation phase shifts to the second stop phase Q2 by second phase
control.
[0136] That is, the first phase control to displace the relative
rotation phase from the predetermined phase K toward the
intermediate locking phase M is started, and the displacement is
stopped at the time when the phase sensor N detects that the
relative rotation phase exceeds the intermediate locking phase M
and reaches the first stop phase Q1 (steps #301 to #303). Next, the
second phase control to displace the relative rotation phase in the
direction opposite to the first phase control is performed, and the
displacement is stopped at the time when the phase sensor N detects
that the relative rotation phase reaches the second stop phase Q2
of the sequence region G (steps #304 to #307).
[0137] In particular, by setting the absolute value of the
displacement speed in the second phase control to a value that is
smaller than the absolute value of the displacement speed in the
first phase control, the displacement speed in the sequence region
G is reduced. As a result, the time during which the relative
rotation phase exists in the sequence region G is increased, and
the discharge of the hydraulic oil from the drain flow path 23D is
sufficiently performed, so that the engaging portion 71b is
reliably fitted into the main lock recess 72.
[0138] Thereafter, when a third operation of displacing the
relative rotation phase toward the intermediate locking phase M is
executed by performing the retardation angle operation and the
control is terminated (step #308).
[0139] (b) As illustrated in FIG. 21, when the phase sensor N
detects that the relative rotation phase reaches the intermediate
locking phase M by a third phase control of the lock shifting
control, a dither control is performed to alternately and
repeatedly supply the hydraulic oil to the retardation angle
chamber Cb and the advance angle chamber Ca for a set time Td, so
that an operation of fitting the lock member 71 into the main lock
recess 72 is reliably performed.
[0140] That is, in this additional embodiment (b), a control to
displace the relative rotation phase as illustrated in the timing
chart of FIG. 22 is performed by a lock shifting control
illustrated in the flowchart of FIG. 23. Since the timing chart of
FIG. 22 and the flowchart illustrated in FIG. 23 add the dither
control of the present embodiment (b) disclosed here to the
above-described embodiment, others excluding the dither control are
common with the description of the above embodiment.
[0141] That is, the first phase control is started to displace the
relative rotation phase toward the intermediate locking phase M by
the retardation angle operation. By this first phase control, the
displacement is stopped at the time when the phase sensor N detects
that the relative rotation phase exceeds the intermediate locking
phase M from the predetermined phase K illustrated in FIG. 5 and
reaches the first stop phase Q1 (steps #401 to #403). In addition,
the steps #401 to #403 correspond to a specific example of the
first phase control.
[0142] Thereafter, the second phase control is started to displace
the relative rotation phase in the direction opposite to the first
phase control by the advance angle operation. In the first stop
phase Q1, since the locking assist flow path 22A communicates with
the opening portion of the large-diameter guide hole portion 70a
(see FIG. 8), an operation of the lock member 71 to the main lock
recess 72 is assisted by the pressure of the hydraulic oil together
with the displacement of the relative rotation phase in the advance
angle direction Sa.
[0143] The relative rotation phase reaches the second stop phase Q2
included in the sequence region G by the advance angle operation
(see FIG. 10). The displacement is stopped at the time when the
phase sensor N detects that the relative rotation phase reaches the
second stop phase Q2 (steps #404 to #406), and the relative
rotation phase waits (stops to operate and stands by) for the first
set time T1. In addition, the steps #404 to #406 correspond to a
specific example of the second phase control.
[0144] In this way, when waiting, the pressure in the retardation
angle flow path 34 and the retardation angle chamber Cb is in a
greatly reduced state. In addition, in the second stop phase Q2, a
state where the opening portion of the large-diameter guide hole
portion 70a of the guide hole 70 communicates with the drain flow
path 23D via the first unlocking flow path 75 and a state where the
communication portion 25 causes the external space to communicate
with the opening portion of the large-diameter guide hole portion
70a of the guide hole 70 are continuously maintained. As a result,
the pressure acting on the first pressure receiving surface U1 and
the second pressure receiving surface U2 is reduced such that an
operation of fitting the engaging portion 71b of the lock member 71
into the main lock recess 72 is performed by the biasing force of
the main lock spring 73.
[0145] Thereafter, the third phase control is performed to displace
the relative rotation phase in the direction of the intermediate
locking phase M by the retardation angle operation. When it is
determined that the relative rotation phase detected by the phase
sensor N reaches the intermediate locking phase M illustrated in
FIG. 21 by the retardation angle operation, the dither control is
performed (steps #407 to #409).
[0146] In the dither control of the step #409, a control signal is
output to the electromagnetic control valve 40 so that the
hydraulic oil is alternately and repeatedly supplied to the advance
angle chamber Ca and the retardation angle chamber Cb for the set
time Td. By performing the dither control, when the relative
rotation phase reaches the intermediate locking phase M and the
engaging portion 71b of the lock member 71 of the main lock
mechanism Lm is already engaged with the main lock recess 72 as
illustrated in FIG. 21, the relative rotation phase is slightly
displaced in the advance angle direction Sa as illustrated in FIG.
22, but is not displaced in the retardation angle direction Sb.
[0147] In addition, by executing this dither control, even if the
side surface of the engaging portion 71b of the lock member 71 and
the side surface of the main lock recess 72 are pressed to come
into contact with each other, a slight gap is intermittently formed
to reduce frictional resistance so that the movement of the lock
member 71 in the engagement direction can be assisted by the
biasing force of the main lock spring 73. As a result, the engaging
portion 71b is reliably shifted to a sufficient depth with respect
to the main lock recess 72.
[0148] In this dither control, since the engaging portion 71b may
be shifted to a sufficient depth into the main lock recess 72 by a
slight displacement of the relative rotation phase, even in a state
where the relative rotation phase is in the intermediate locking
phase M and the regulation end 81a of the lock body 81 of the
auxiliary lock mechanism Ls is engaged with the auxiliary lock
recess 82, the relative rotation phase is displaced in the advance
angle direction Sa and the retardation angle direction Sb according
to a slight gap between the regulation end 81a and the auxiliary
lock recess 82, so that the shifting of the main lock mechanism Lm
to the locked state can be implemented.
[0149] In addition, the timing to start the dither control may be
either immediately after the relative rotation phase reaches the
intermediate locking phase M or the time when a slight time has
elapsed. In addition, the number of times of supplying the
hydraulic oil alternately to the advance angle chamber Ca and the
retardation angle chamber Cb, or the interval when the hydraulic
oil is alternately supplied may be arbitrarily set.
[0150] After the dither control is executed as described above,
when the relative rotation phase is shifted to the locked state in
the intermediate locking phase M by performing the control to
perform the retardation angle operation, the relative rotation
phase is not displaced, and when the relative rotation phase is not
shifted to the locked state and when the phase sensor N detects
that the relative rotation phase exceeds the intermediate locking
phase M and is displaced to the retardation angle side, the retry
control (step #200) is executed. The retry control is common with
the description of the above-described exemplary embodiment, and
thus a control form is the same as that illustrated in FIG. 14.
[0151] (c) In the control of the embodiment (a), the dither control
is executed. That is, after the step #308 of the flowchart of FIG.
19, the dither control (step #409) described in the embodiment (b)
is executed so that the operation of shifting the engaging portion
71b of the lock member 71 to a sufficient depth into the main lock
recess 72 is reliably performed.
[0152] (d) After the retry control (see FIG. 14), a control mode is
set to perform the dither control when the relative rotation phase
reaches the intermediate locking phase M (step #108 of the
flowchart of FIG. 13). By setting the control mode in this manner,
the movement of the lock member 71 in the engaging direction is
assisted by the biasing force of the main lock spring 73, and the
engaging portion 71b is reliably shifted to a sufficient depth into
the main lock recess 72.
[0153] In particular, when executing the dither control in the
retry control, it is considered that, when the set time Td during
which the dither control is executed is longer than the set time Td
of the dither control in the lock shifting control, the number of
times of displacement of the relative rotation phase in the advance
angle direction Sa and the retardation angle direction Sb is
increased.
[0154] (e) In the lock shifting control, the time during which the
relative rotation phase waits after reaching the sequential region
G may be changed according to the hydraulic pressure and the
rotational speed of the engine E.
[0155] As a specific control form, by extending the waiting time as
the hydraulic pressure is increased, it is considered that, after
the pressure of the hydraulic oil acting on the lock member 71 is
removed, the pressure of the hydraulic oil continuously acting on
the lock member 71 is reliably removed. In addition, by extending
the waiting time as the rotational speed is increased, it is
considered that an operation is performed under the influence of
frictional force acting on the lock member 71 due to centrifugal
force.
[0156] Similarly to this, the degree by which the displacement
speed of the relative rotation phase is reduced may be changed
according to the hydraulic pressure and the rotational speed of the
engine E by the lock shifting control described in the exemplary
embodiment (a).
[0157] (f) In the case where the retry control is performed in the
lock shifting control, the waiting time at the time of performing
the shifting to the locked state is stored to be associated with
the temperature of the engine E, the hydraulic pressure, or the
rotational speed of the engine E. Then, when performing the lock
shifting control, a control form may be set to set the waiting time
that is suitable for a stored condition.
[0158] By setting the waiting time based on the stored information
as described above, reliable shifting to the locked state is
enabled. The control based on the stored information may also be
applied to the speed limitation of the above-described embodiment
(a).
[0159] (g) As a hydraulic fluid control mechanism, an
electromagnetic valve may be provided outside the valve
opening/closing timing control device A. In this configuration, a
flow path configuration may be simplified compared to a case where
an electromagnetic valve is provided inside the valve
opening/closing timing control device A.
[0160] (h) As a modification of the configuration in which the main
lock mechanism Lm is provided in the vane portion 32, the lock
member 71 may be configured to protrude outward in the radial
direction. In addition, as the auxiliary lock mechanism Ls, the
lock body 81 may be configured to move inward or outward along an
axis that is parallel to the rotation axis X.
[0161] (i) The electromagnetic control valve 40 may be configured
such that the advance angle position and the retardation angle
position are disposed in the reverse order.
[0162] This disclosure may be applied to a valve opening/closing
timing control device, which includes a driving side rotating body,
a driven side rotating body, and a lock mechanism to restrain these
rotating bodies in a predetermined relative rotation phase.
[0163] A feature of an aspect of this disclosure resides in that a
valve opening/closing timing control apparatus includes: a driving
side rotating body configured to rotate synchronously with a
crankshaft of an internal combustion engine; a driven side rotating
body included in the driving side rotating body and configured to
rotate integrally with a camshaft for opening or closing of a valve
of the internal combustion engine on a same axis as a rotation axis
of the driving side rotating body; a hydraulic fluid control
mechanism configured to displace a relative rotation phase between
the driving side rotating body and the driven side rotating body by
supplying a hydraulic fluid to one of an advance angle chamber and
a retardation angle chamber, which are defined between the driving
side rotating body and the driven side rotating body; and a lock
mechanism including a lock member slidably inserted into a guide
hole formed in one of the driving side rotating body and the driven
side rotating body, a biasing member configured to bias the lock
member in a direction where an engaging portion on one end side of
the lock member protrudes, and a lock recess formed in a remaining
one of the driving side rotating body and the driven side rotating
body so as to allow the engaging portion to be fitted thereinto.
The lock member includes the engaging portion, a main body portion
having a larger diameter than that of the engaging portion, and a
first pressure receiving surface formed in an annular shape on an
end surface of the main body portion at an intermediate position
between the engaging portion and the main body portion. The valve
opening/closing timing control apparatus further includes: a first
unlocking flow path configured to communicate with the first
pressure receiving surface when the engaging portion is moved from
a locking position where the engaging portion is fitted into the
lock recess to a position at which the engaging portion is farther
spaced apart from the lock recess than at a locking boundary
position where the engaging portion is separated from the lock
recess; and a second unlocking flow path configured to communicate
with the first pressure receiving surface when the engaging portion
is at an unlocking position at which the engaging portion is
farther spaced apart from the lock recess than at the locking
boundary position, and to be in non-communication state with the
first pressure receiving surface as a flow path is closed by the
main body portion when the engaging portion is at the locking
boundary position.
[0164] According to this configuration, in a locked state where the
engaging portion of the lock member is fitted into the lock recess,
when the hydraulic fluid is supplied to the first unlocking flow
path, the pressure of the hydraulic fluid is applied to the first
pressure receiving surface so as to extract the engaging portion
from the lock recess, thereby implementing shifting to an unlocked
state. In addition, when the engaging portion of the lock member
reaches the unlocking position after shifting to the unlocked
state, it is also possible to cause the pressure of the hydraulic
fluid to act on the first pressure receiving surface so that the
unlocked state can be maintained by supplying the hydraulic fluid
to the second unlocking flow path.
[0165] In addition, in a state in which the engaging portion of the
lock member is closer to the locking direction than the locking
boundary position, the second unlocking flow path is closed by the
main body portion of the lock member. Therefore, a phenomenon in
which the hydraulic fluid flows into/flows out from the second
unlocking flow path is not caused when the engaging portion of the
lock member moves toward the lock recess by the biasing force of
the biasing member, and the operating speed of the lock member is
not suppressed. For example, in a configuration in which the
hydraulic fluid flows into the second unlocking flow path when the
lock member shifts to the locked state, the operating speed of the
lock member is reduced since the flow of the hydraulic fluid is
suppressed by the resistance in the second unlocking flow path.
However, the configuration of the present invention solves this
problem.
[0166] Accordingly, the valve opening/closing timing control
apparatus in which the lock member can be rapidly fitted into the
lock recess is configured.
[0167] In the aspect of this disclosure, the lock recess may
include a fittable region that extends in a displacement direction
to enable displacement of the relative rotation phase in a state
where the engaging portion is fitted into the lock recess, and a
phase in which the engaging portion is fitted into one side end of
the fittable region of the lock recess in the displacement
direction may be set to a locking phase. A range of the fittable
region under influence of the set locking phase may be set to a
sequence region, and in the sequence region, a drain flow path
configured to discharge the hydraulic fluid may communicate with
the first unlocking flow path. An unlocking phase may be set to be
opposite to the locking phase on the basis of the sequence region
in the fittable region, and in the unlocking phase, the first
unlocking flow path and the drain flow path are in
non-communication state with each other in a state where the
engaging portion is fitted into the lock recess, and supply of the
hydraulic fluid to the first unlocking flow path and the second
unlocking flow path is enabled.
[0168] According to this configuration, by setting the relative
rotation phase to the sequence region, the hydraulic fluid that
applies pressure to the first pressure receiving surface may be
discharged from the first unlocking flow path to the drain flow
path so that the pressure acting on the first pressure receiving
surface can be reduced, and an operation of fitting the engaging
portion of the lock member into the lock recess can be
performed.
[0169] In addition, when the state of setting the relative rotation
phase to the sequence region is maintained, shifting to the locked
state can be reliably implemented.
[0170] Further, by setting the relative rotation phase to an
unlocking phase, no hydraulic fluid is discharged from the drain
flow path and the hydraulic fluid is supplied from the first
unlocking flow path and the second unlocking flow path so that
shifting to the unlocked state can be rapidly performed.
[0171] In the aspect of this disclosure, the valve opening/closing
timing control apparatus may further include: a phase sensor
configured to detect the relative rotation phase; and a lock
shifting control unit configured to: start a first phase control so
as to displace the relative rotation phase from a predetermined
phase, which is opposite to the locking phase on the basis of the
sequence region, to the locking phase; stop the displacement by the
first phase control at a time when the phase sensor detects that
the relative rotation phase exceeds the locking phase from the
predetermined phase; start a second phase control so as to displace
the relative rotation phase in a direction opposite to that in the
first phase control; stop the displacement by the second phase
control at a time when the phase sensor detects that the relative
rotation phase reaches a predetermined phase in the sequence
region; and start a third phase control so as to displace the
relative rotation phase toward the locking phase.
[0172] According to this configuration, when the lock shifting
control unit performs the first phase control, the displacement is
stopped when the relative rotation phase exceeds the sequence
region and the locking phase. Subsequently, when the lock shifting
control unit performs the second phase control, the displacement is
stopped when the relative rotation phase exceeds the locking phase
and reaches a phase included in the sequence region. In the
sequence region, since the engaging portion of the lock member is
fittable into the lock recess and the hydraulic fluid is discharged
from the first unlocking flow path to the drain flow path, an
operation of fitting the engaging portion into the lock recess can
be performed by the biasing force of the biasing member.
Thereafter, when the lock shifting control unit performs the third
phase control to displace the relative rotation phase toward the
locking phase, the engaging portion may be abutted on the end
surface of the inner end of the lock recess, which becomes a
locking position so that the shifting to the locking phase can be
performed.
[0173] In the aspect of this disclosure, in the second phase
control, when the relative rotation phase reaches the sequence
region and the displacement is stopped, the stop may be continued
for a set time.
[0174] According to this configuration, for example, as in a case
where the hydraulic fluid has high viscosity due to the low
temperature thereof, even if the hydraulic fluid is not smoothly
discharged from the drain flow path and the reduction in the
pressure of the first unlocking flow path requires an extra time,
it is possible to cause the hydraulic fluid to be sufficiently
discharged and to cause the engaging portion to be reliably fitted
into the lock recess by continuing the stop for the set time in the
sequence region.
[0175] In the aspect of this disclosure, a control form of the lock
shifting control unit may be set: to start a fourth phase control
to stop the displacement when the phase sensor detects that the
relative rotation phase exceeds the locking phase and is displaced
to a predetermined phase after the third phase control, and
thereafter displace the relative rotation phase in the same
direction as the second phase control; to stop the fourth phase
control at a time when the phase sensor detects that the relative
rotation phase reaches a predetermined phase in the sequence
region; to maintain the stopped state for a longer time than the
set time; and then to perform a fifth phase control to displace the
relative rotation phase toward the locking phase.
[0176] When the relative rotation phase is displaced beyond the
locking phase after the third phase control, the engaging portion
of the lock member is not fitted into the lock recess. Thus, the
displacement by the third phase control is continuously stopped to
the second phase control start position. Thereafter, the relative
rotation phase is shifted to the sequence region and then stopped
by performing the fourth phase control, and by maintaining the stop
time to be longer than the previous set time, it becomes possible
to perform an operation in which the engaging portion is fitted
into the lock recess by the biasing force of the biasing member. In
addition, by subsequently performing the fifth phase control,
shifting to the locking phase can be reliably performed.
[0177] In the aspect of this disclosure, an absolute value of a
displacement speed in the second phase control may be set to be
smaller than an absolute value of a displacement speed in the first
phase control.
[0178] According to this configuration, even if the hydraulic fluid
is not smoothly discharged from the drain flow path and the
reduction in the pressure of the first unlocking flow path requires
an extra time as in a case where the hydraulic fluid has high
viscosity due to, for example, a low temperature thereof, it is
possible to allow the fitting of the engaging portion into the lock
recess to be reliably performed by reducing the displacement speed
of the relative rotation phase in the second phase control to be
lower than the displacement speed in the first phase control so
that the drain time can be extended and the hydraulic fluid can be
sufficiently discharged.
[0179] In the aspect of this disclosure, in the second phase
control, the displacement speed in the sequence region may be
reduced with respect to the displacement speed before reaching the
sequence region.
[0180] In the aspect of this disclosure, the lock shifting control
unit may perform a dither control to alternately and repeatedly
supply the fluid into the advance angle chamber and the retardation
angle chamber within a set time when the phase sensor detects that
the relative rotation phase reaches the locking phase by the third
phase control.
[0181] According to this configuration, when the relative rotation
phase is displaced toward the locking phase in the lock shifting
control to reach the locking phase, the operation of causing the
engaging portion of the lock member to be engaged with the lock
recess is performed by the biasing force of the biasing member.
However, it is also conceivable that when the engaging portion is
pressed to come into contact with the inner circumferential wall of
the lock recess so that the frictional resistance is increased, a
problem may be caused in that the engaging portion is not inserted
to a sufficient depth. In connection with this, by performing the
dither control when the relative rotation phase reaches the locking
phase, the frictional resistance may be reduced by releasing the
pressure contact state in the press contact portion between the
engaging portion and the lock recess, so that the engaging portion
can be inserted into the lock recess to a sufficient depth.
[0182] In the aspect of this disclosure, a locking assist flow path
may be formed to apply a pressure of the hydraulic fluid to the
lock member in an engagement direction when the relative rotation
phase is opposite to the sequence region on the basis of the
locking phase.
[0183] According to this configuration, for example, when the
relative rotation phase is displaced from the phase, which is
opposite to the locking phase on the basis of the sequence region,
toward the locking phase, the pressure of the hydraulic fluid acts
on the lock member in the engagement direction from the locking
assist flow path. This also enables the operating speed of the
engaging portion of the lock member toward the lock recess to be
increased.
[0184] In the aspect of this disclosure, the valve opening/closing
timing control apparatus may further include: an auxiliary lock
mechanism including a lock body slidably inserted into a support
hole portion formed in one of the driving side rotating body and
the driven side rotating body, a biasing body configured to bias a
regulation end on one end side of the lock body so that the
regulation end protrudes, and an auxiliary lock recess formed in a
remaining one of the driving side rotating body and the driven side
rotating body so that the regulation end of the lock body is fitted
into the auxiliary lock recess by biasing force of the biasing
body. The auxiliary lock recess may be formed in a region extending
along the displacement direction of the relative rotation phase so
that the displacement of the relative rotation phase is enabled in
a state where the regulation end is fitted into the auxiliary lock
recess. In a state where the relative rotation phase is in the
locking phase, the lock body may be disposed at a position at which
the lock body inhibits the displacement of the relative rotation
phase between both ends of the auxiliary lock recess in the
displacement direction.
[0185] According to this configuration, when the relative rotation
phase is in the locking phase, the lock body is fitted into the
auxiliary lock recess and the lock member is fitted into the lock
recess. Thus, in this state, the relative rotation phase may not be
displaced in any one of an advance angle direction and a
retardation angle direction, and may be maintained at an
intermediate phase between the maximum advance angle phase and the
maximum retardation angle phase.
[0186] In the aspect of this disclosure, one of the driving side
rotating body and the driven side rotating body may be configured
as an inner rotor having the guide hole formed therein, and a
remaining one of the driving side rotating body and the driven side
rotating body may be configured as an outer rotor having a pair of
plates for fitting of the inner rotor therebetween, the lock recess
being formed in one of the plates, and a communication portion
being formed in a remaining one of the plates so as to enable
communication between the guide hole and an external space. As the
relative rotation phase approaches the locking phase in the
sequence region, a flow path area of the communication portion
communicating with the external space may be reduced and a flow
path area of the drain flow path communicating with the first
unlocking flow path may be increased, and in the second phase
control, when the flow path area of the communication portion and
the flow path area of the drain flow path reach 20% or more of that
in a completely opened state, the displacement by the second phase
control may stop.
[0187] According to this configuration, when the displacement of
the relative rotation phase by the third phase control causes each
of the flow path area of the communication portion and the flow
path area of the drain flow path reaches 20% or more of that in the
completely opened state, a control to stop the third phase control
is performed. With this stop, a resistance acting on air suctioned
from the communication portion to the space of the guide hole in
which the biasing member is located is reduced, and a resistance
acting on the fluid discharged from the first unlocking flow path
to the drain flow path is reduced. As a result, the displacement
speed of the lock member is increased so that shifting to the
locked state can be rapidly performed.
[0188] In the aspect of this disclosure, the set time of the dither
control performed after the fifth control may be set to be longer
than the set time of the dither control performed after the third
control.
[0189] In the aspect of this disclosure, in the lock shifting
control, a duration in which the relative rotation phase reaches
the sequence region and the displacement is stopped may be changed
according to a hydraulic pressure and a number of revolutions of
the internal combustion engine.
[0190] The principles, preferred embodiment and mode of operation
of the present invention have been described in the foregoing
specification. However, the invention which is intended to be
protected is not to be construed as limited to the particular
embodiments disclosed. Further, the embodiments described herein
are to be regarded as illustrative rather than restrictive.
Variations and changes may be made by others, and equivalents
employed, without departing from the spirit of the present
invention. Accordingly it is expressly intended that all such
variations, changes and equivalents which fall within the spirit
and scope of the present invention as defined in the claims, be
embraced thereby.
* * * * *