U.S. patent application number 17/110416 was filed with the patent office on 2021-06-10 for valve opening and closing timing control device.
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 Jaroslav BECV R, Tomohiro KAJITA, Yoshihiro KAWAI, Masaki KOBAYASHI, Yuji NOGUCHI, Kazuo UEDA.
Application Number | 20210172346 17/110416 |
Document ID | / |
Family ID | 1000005259982 |
Filed Date | 2021-06-10 |
United States Patent
Application |
20210172346 |
Kind Code |
A1 |
UEDA; Kazuo ; et
al. |
June 10, 2021 |
VALVE OPENING AND CLOSING TIMING CONTROL DEVICE
Abstract
A valve opening and closing timing control device includes: a
drive-side rotary body rotating synchronously with a crankshaft; a
driven-side rotary body provided inside the drive-side rotary body
coaxial with the drive-side rotary body and rotating integrally
with a camshaft; advance and retard chambers formed between the
drive-side and driven-side rotary bodies; a valve unit including a
spool and controlling supply and discharge of fluid to and from the
advance and retard chambers; a tubular valve case having an
internal space extending along the rotation axis inside the
driven-side rotary body and housing the valve unit; first and
second drain flow paths through which the fluid is discharged from
one and the other of the advance and retard chambers, respectively,
through the spool. The first drain and second drain flow paths
extend in directions intersecting each other at different positions
in the rotation axis direction.
Inventors: |
UEDA; Kazuo; (Kariya-shi,
JP) ; NOGUCHI; Yuji; (Kariya-shi, JP) ; KAWAI;
Yoshihiro; (Kariya-shi, JP) ; KOBAYASHI; Masaki;
(Kariya-shi, JP) ; KAJITA; Tomohiro; (Kariya-shi,
JP) ; BECV R; Jaroslav; (Cizovska, CZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AISIN SEIKI KABUSHIKI KAISHA |
Kariya-shi |
|
JP |
|
|
Assignee: |
AISIN SEIKI KABUSHIKI
KAISHA
Kariya-shi
JP
|
Family ID: |
1000005259982 |
Appl. No.: |
17/110416 |
Filed: |
December 3, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01L 1/3442 20130101;
F01L 2001/34463 20130101; F01L 1/047 20130101; F01L 2001/34426
20130101 |
International
Class: |
F01L 1/344 20060101
F01L001/344; F01L 1/047 20060101 F01L001/047 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 2019 |
JP |
2019-221341 |
Claims
1. A valve opening and closing timing control device comprising: a
drive-side rotary body that rotates synchronously with a crankshaft
of an internal combustion engine; a driven-side rotary body that is
provided inside the drive-side rotary body in a state of being
coaxial with a rotation axis of the drive-side rotary body and that
rotates integrally with a camshaft for opening and closing a valve;
an advance chamber and a retard chamber formed between the
drive-side rotary body and the driven-side rotary body; a valve
unit that includes a spool movable in a rotation axis direction and
that controls supply and discharge of fluid to and from the advance
chamber and the retard chamber; a tubular valve case that has an
internal space extending along the rotation axis inside the
driven-side rotary body in a radial direction and that houses the
valve unit in the internal space; a first drain flow path through
which the fluid is discharged from any one of the advance chamber
or the retard chamber through the spool; and a second drain flow
path through which the fluid is discharged from the other one of
the advance chamber or the retard chamber through the spool,
wherein the first drain flow path and the second drain flow path
extend in directions intersecting each other at different positions
in the rotation axis direction.
2. The valve opening and closing timing control device according to
claim 1, wherein in the valve case, the first drain flow path is
formed to extend in the rotation axis direction and the second
drain flow path is formed to extend in a radial direction
orthogonal to the rotation axis direction.
3. The valve opening and closing control device according to claim
1, further comprising: a lock mechanism that restrains a relative
rotation phase of the driven-side rotary body with respect to the
drive-side rotary body to an intermediate phase between a most
retarded phase and a most advanced phase, wherein the fluid
supplied to the lock mechanism is discharged from the first drain
flow path.
4. The valve opening and closing control device according to claim
2, further comprising: a lock mechanism that restrains a relative
rotation phase of the driven-side rotary body with respect to the
drive-side rotary body to an intermediate phase between a most
retarded phase and a most advanced phase, wherein the fluid
supplied to the lock mechanism is discharged from the first drain
flow path.
5. The valve opening and closing control device according to claim
1, further comprising: a lock mechanism that restrains a relative
rotation phase of the driven-side rotary body with respect to the
drive-side rotary body to a most retarded phase or a most advanced
phase, wherein the fluid supplied to the lock mechanism is
discharged from the first drain flow path.
6. The valve opening and closing timing control device according to
claim 4, wherein the second drain flow path includes a through hole
of the valve case along a direction intersecting the rotation axis
direction.
7. The valve opening and closing timing control device according to
claim 5, wherein the first drain flow path includes a hole portion
along the rotation axis direction of the valve case.
8. The valve opening and closing timing control device according to
claim 6, wherein the first drain flow path includes a hole portion
along the rotation axis direction of the valve case.
9. The valve opening and closing timing control device according to
claim 5, wherein the first drain flow path is formed between an
outer end portion of the spool and the valve case.
10. The valve opening and closing timing control device according
to claim 6, wherein the first drain flow path is formed between an
outer end portion of the spool and the valve case.
11. The valve opening and closing timing control device according
to claim 1, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
12. The valve opening and closing timing control device according
to claim 2, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
13. The valve opening and closing timing control device according
to claim 3, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
14. The valve opening and closing timing control device according
to claim 4, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
15. The valve opening and closing timing control device according
to claim 5, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
16. The valve opening and closing timing control device according
to claim 6, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
17. The valve opening and closing timing control device according
to claim 7, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
18. The valve opening and closing timing control device according
to claim 8, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
19. The valve opening and closing timing control device according
to claim 9, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
20. The valve opening and closing timing control device according
to claim 10, wherein when the spool is at one of a movement start
position or a movement end position, the fluid is discharged from
the first drain flow path, and when the spool is at the other one
of the movement start position or the movement end position, the
fluid is discharged from the second drain flow path.
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 2019-221341, filed
on Dec. 6, 2019, the entire content of which is incorporated herein
by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a valve opening and closing
timing control device that controls opening and closing timing of a
valve.
BACKGROUND DISCUSSION
[0003] A valve opening and closing timing control device includes a
drive-side rotary body that rotates synchronously with a crankshaft
of an internal combustion engine, and a driven-side rotary body
that is arranged coaxially with a rotation axis of the drive-side
rotary body and rotates integrally with a camshaft for opening and
closing a valve. By supplying fluid to and discharging fluid from
an advance chamber and a retard chamber formed between the
drive-side rotary body and the driven-side rotary body, a relative
rotation phase between the drive-side rotary body and the
driven-side rotary body is controlled. It is known that the valve
opening and closing timing control device includes a valve unit
that controls the supply of the fluid to and discharge of the fluid
from the advance chamber and the retard chamber, and a coupling
bolt that houses the valve unit in an internal space in a direction
along the rotation axis (for example, see JP-A-2018-91226
(Reference 1)).
[0004] In the valve opening and closing timing control device
described in Reference 1, as the valve unit, a sleeve, a spool
movable in the rotation axis direction, and a fluid supply pipe are
arranged in order from an outer side to an inner side in a radial
direction in the internal space of the coupling bolt. Further, the
valve opening and closing timing control device includes a lock
mechanism that can switch between a lock state in which the valve
opening and closing timing control device is restrained to an
intermediate phase between a most retarded phase and a most
advanced phase and a lock release state in which the restraint of
the intermediate phase is released.
[0005] Reference 1 discloses an embodiment in which, in the lock
state, a lock drain flow path through which the fluid is discharged
from the lock mechanism extends in the rotation axis direction of
the coupling bolt, and an advance chamber drain flow path through
which the fluid is discharged from the advance chamber extends in
the rotation axis direction of the coupling bolt as a flow path
different from the lock drain flow path. The lock drain flow path
also serves as a retard chamber drain flow path through which the
fluid is discharged from the retard chamber. That is, the advance
chamber drain flow path and the retard chamber drain flow path
extending in the rotation axis direction are arranged at different
positions in a circumferential direction on the coupling bolt.
[0006] In the valve opening and closing timing control device
described in Reference 1, a plurality of drain flow paths in the
rotation axis direction are extended to the coupling bolt.
Accordingly, a flow path cross-sectional area of the advance
chamber drain flow path and the retard chamber drain flow path for
phase control is limited. As a result, at the time of the phase
control, a speed at which the fluid is discharged from the advance
chamber or the retard chamber may be reduced, and responsiveness of
the phase control may be deteriorated.
[0007] A need thus exists for a valve opening and closing timing
control device which is not susceptible to the drawback mentioned
above.
SUMMARY
[0008] A characteristic configuration of a valve opening and
closing timing control device according to an aspect of this
disclosure resides in that the valve opening and closing timing
control device includes a drive-side rotary body that rotates
synchronously with a crankshaft of an internal combustion engine; a
driven-side rotary body that is provided inside the drive-side
rotary body in a state of being coaxial with a rotation axis of the
drive-side rotary body and that rotates integrally with a camshaft
for opening and closing a valve; an advance chamber and a retard
chamber formed between the drive-side rotary body and the
driven-side rotary body; a valve unit that includes a spool movable
in a rotation axis direction and that controls supply and discharge
of fluid to and from the advance chamber and the retard chamber; a
tubular valve case that has an internal space extending along the
rotation axis inside the driven-side rotary body in a radial
direction and that houses the valve unit in the internal space; a
first drain flow path through which the fluid is discharged from
any one of the advance chamber or the retard chamber through the
spool; and a second drain flow path through which the fluid is
discharged from the other one of the advance chamber or the retard
chamber through the spool, in which the first drain flow path and
the second drain flow path extend in directions intersecting each
other at different positions in the rotation axis direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] 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:
[0010] FIG. 1 is a cross-sectional view showing a valve opening and
closing timing control device;
[0011] FIG. 2 is a cross-sectional view taken along a line II-II of
FIG. 1;
[0012] FIG. 3 is a diagram listing a relationship between a
position of a spool and supply and discharge of working oil;
[0013] FIG. 4 is a cross-sectional view of a valve unit in which
the spool is in a first advance position;
[0014] FIG. 5 is a cross-sectional view of the valve unit in which
the spool is in a second advance position;
[0015] FIG. 6 is a cross-sectional view of the valve unit in which
the spool is in a neutral position;
[0016] FIG. 7 is a cross-sectional view of the valve unit in which
the spool is in a retard position;
[0017] FIG. 8 is a cross-sectional view showing a valve opening and
closing timing control device according to a first alternative
embodiment;
[0018] FIG. 9 is a cross-sectional view showing a valve opening and
closing timing control device according to a second alternative
embodiment;
[0019] FIG. 10 is a cross-sectional view taken along a line X-X of
FIGS. 8 and 9; and
[0020] FIG. 11 is a diagram listing a relationship between a
position of a spool and supply and discharge of working oil
according to another embodiment.
DETAILED DESCRIPTION
[0021] Embodiments of a valve opening and closing timing control
device disclosed here will be described below with reference to the
drawings. However, this disclosure is not limited to the following
embodiments, and various modifications can be made without
departing from the scope of this disclosure.
[Basic Configuration]
[0022] As shown in FIGS. 1 and 2, a valve opening and closing
timing control device A includes an external rotor 20 as a
drive-side rotary body, an internal rotor 30 as a driven-side
rotary body, and an electromagnetic control valve V that controls
supply and discharge of working oil as a working fluid. Since the
valve opening and closing timing control device A sets an opening
and closing timing (opening and closing period) of an intake
camshaft 5 (an example of a camshaft) of an engine E (an example of
an internal combustion engine) of a vehicle such as a passenger
car, the valve opening and closing timing control device A is
provided coaxially with a rotation axis X of the intake camshaft
5.
[0023] The internal rotor 30 (an example of the driven-side rotary
body) is arranged coaxially with the rotation axis X of the intake
camshaft 5 (external rotor 20), and is integrally rotated with the
intake camshaft 5 by being coupled to the intake camshaft 5 by a
coupling bolt 40 (an example of a valve case). The internal rotor
30 is provided inside the external rotor 20. The external rotor 20
(an example of the drive-side rotary body) is arranged coaxially
with the rotation axis X and rotates synchronously with a
crankshaft 1 of the engine E. With this configuration, the external
rotor 20 and the internal rotor 30 are relatively rotatable.
[0024] The valve opening and closing timing control device A
includes a lock mechanism L that holds a relative rotation phase
between the external rotor 20 and the internal rotor 30
(hereinafter simply referred to as "relative rotation phase") at an
intermediate lock phase M (an example of an intermediate phase)
shown in FIG. 2. The intermediate lock phase M is a phase between a
most retarded phase and a most advanced phase. The valve opening
and closing timing control device A is controlled to shift to the
intermediate lock phase M at the time of stop control of the engine
E as an opening and closing timing suitable for starting the engine
E. The shift control to the intermediate lock phase M may be
executed when the engine E is started.
[0025] The electromagnetic control valve V includes an
electromagnetic unit Va and a valve unit Vb supported by the engine
E.
[0026] The electromagnetic unit Va includes a solenoid portion 50
and a plunger 51 that is arranged coaxially with the rotation axis
X and protrudes and retracts by drive control of the solenoid
portion 50. In the valve unit Vb, a spool 55 that controls the
supply and discharge of the working oil (an example of fluid) is
arranged coaxially with the rotation axis X, and has a position
relationship set such that a protrusion end of the plunger 51 abuts
against an outer end of the spool 55.
[0027] The electromagnetic control valve V sets a protrusion amount
of the plunger 51 by controlling electric power supplied to the
solenoid portion 50, and operates the spool 55. By this operation,
the electromagnetic control valve V controls a flow of the working
oil to set an opening and closing timing of an intake valve 5V, and
performs switching between a lock state in which the lock mechanism
L is restrained to the intermediate lock phase M and a lock release
state in which the restraint of the intermediate lock phase M is
released. A configuration and a control mode of the electromagnetic
control valve V will be described later.
[0028] As shown in FIG. 1, the engine E is a four-cycle type engine
in which a piston 3 is housed in a cylinder bore of a cylinder
block 2 at an upper position, and the piston 3 and the crankshaft 1
are coupled by a coupling rod 4. An upper portion of the engine E
includes the intake camshaft 5 for opening and closing the intake
valve 5V and an exhaust camshaft (not shown).
[0029] A support member 10 that rotatably supports the intake
camshaft 5 is formed with a supply flow path 8 through which the
working oil is supplied from a hydraulic pump P driven by the
engine E. The hydraulic pump P supplies lubricating oil stored in
an oil pan of the engine E to the valve unit Vb as the working oil
through the supply flow path 8.
[0030] A timing chain 7 is wound around an output sprocket 6 formed
on the crankshaft 1 of the engine E and a timing sprocket 21S of
the external rotor 20. Accordingly, the external rotor 20 rotates
synchronously with the crankshaft 1. A sprocket is also provided at
a front end of the exhaust camshaft on an exhaust side, and the
timing chain 7 is also wound around the sprocket.
[0031] As shown in FIG. 2, the external rotor 20 rotates in a drive
rotation direction S by a driving force from the crankshaft 1. A
direction in which the internal rotor 30 rotates relative to the
external rotor 20 in the same direction as the drive rotation
direction S is referred to as an advance direction Sa, and a
reverse direction to the direction is referred to as a retard
direction Sb. In the valve opening and closing timing control
device A, a relationship between the crankshaft 1 and the intake
camshaft 5 is set such that an intake compression ratio is
increased as a displacement amount when the relative rotation phase
is displaced in the advance direction Sa increases, and the intake
compression ratio is reduced as a displacement amount when the
relative rotation phase is displaced in the retard direction Sb
increases.
[0032] The present embodiment describes the valve opening and
closing timing control device A provided on the intake camshaft 5.
The valve opening and closing timing control device A may be
provided on the exhaust camshaft, and may be provided on both the
intake camshaft 5 and the exhaust camshaft.
[0033] As shown in FIG. 1, the external rotor 20 includes an
external rotor body 21, a front plate 22, and a rear plate 23,
which are integrated by fastening a plurality of fastening bolts
24. The timing sprocket 21S is formed on an outer periphery of the
external rotor body 21.
[0034] As shown in FIG. 2, a plurality of (three in the present
embodiment) protrusion portions 21T protruding inward in a radial
direction are integrally formed on the external rotor body 21. The
internal rotor 30 includes a columnar internal rotor body 31 that
is in close contact with the protrusion portions 21T of the
external rotor body 21, and a plurality of vane portions 32 (three
in the present embodiment) protruding outward in the radial
direction from an outer periphery of the internal rotor body 31 so
as to come into contact with an inner peripheral surface of the
external rotor body 21.
[0035] As described above, the internal rotor 30 is provided inside
the external rotor 20, and a plurality of (three in the present
embodiment) fluid pressure chambers C are formed on an outer
peripheral side of the internal rotor body 31 at positions between
a pair of protrusion portions 21T adjacent to each other in the
rotation direction. The fluid pressure chambers C are partitioned
by the vane portions 32, and thus advance chambers Ca and retard
chambers Cb are partitioned. Further, the internal rotor body 31 is
formed with advance flow paths 33 communicating with the advance
chambers Ca and retard flow paths 34 communicating with the retard
chambers Cb.
[0036] As shown in FIGS. 1 and 2, the lock mechanism L includes a
lock member 25 that is supported to be freely protruded and
retracted in the radial direction with respect to each of the two
protrusion portions 21T of the external rotor 20, a lock spring 26
that protrudes and biases the lock member 25, and a lock recess 27
formed on the outer periphery of the internal rotor body 31. A lock
control flow path 35 communicating with the lock recess 27 is
formed in the internal rotor body 31.
[0037] The lock mechanism L functions to regulate the relative
rotation phase to the intermediate lock phase M by simultaneously
engaging the two lock members 25 with the corresponding lock
recesses 27 by a biasing force of the lock spring 26. By supplying
the working oil to the lock control flow path 35 in this lock
state, the lock member 25 is disengaged from the lock recess 27
against the biasing force of the lock spring 26 to release the lock
state (lock release state). Conversely, by discharging the working
oil from the lock control flow path 35, the lock member 25 that
receives the biasing force of the lock spring 26 is engaged with
the lock recess 27 to allow the lock member 25 to shift to the lock
state.
[0038] The lock mechanism L may be configured by engaging the
single lock member 25 with the corresponding single lock recess 27.
Further, the lock mechanism L may have a configuration in which the
lock member 25 is guided so as to move in the rotation axis X
direction.
[Coupling Bolt]
[0039] As shown in FIGS. 1 and 4, the coupling bolt 40 (an example
of the valve case) is integrally formed with a bolt body 41 which
is generally tubular and a bolt head 42 on an outer end side (left
side in FIG. 4). An internal space 40R that runs in the rotation
axis X direction is formed inside the coupling bolt 40, and a male
screw portion 41S is formed on an outer periphery of an inner end
side (right side in FIG. 4) of the bolt body 41. An annular
constriction portion 41A, which is an annular groove along the
outer periphery of the bolt body 41, is formed on an outer end side
of the bolt body 41 adjacent to the male screw portion 41S.
[0040] As shown in FIG. 1, the intake camshaft 5 defines an axial
internal space 5R centered on the rotation axis X, and a female
screw portion 5S is formed on an inner periphery of the axial
internal space 5R. The axial internal space 5R communicates with
the supply flow path 8 and is supplied with the working oil from
the hydraulic pump P.
[0041] With this configuration, the bolt body 41 is inserted into
the internal rotor 30, the male screw portion 41S is screwed to the
female screw portion 5S of the intake camshaft 5, and the internal
rotor 30 is fastened to the intake camshaft 5 by the rotation
operation of the bolt head 42. By the fastening, the internal rotor
30 is fixed to the intake camshaft 5, and the axial internal space
5R and the internal space 40R of the coupling bolt 40 (strictly, an
internal space of a fluid supply pipe 54) communicate with each
other.
[0042] As shown in FIG. 4, a regulation wall 44 is formed on the
outer end side of the inner peripheral surface of the internal
space 40R of the coupling bolt 40 in the rotation axis X direction.
The regulation wall 44 protrudes in a direction of approaching the
rotation axis X. The regulation wall 44 regulates a protrusion
position by abutting a land portion 55b on an outer end side of the
spool 55, which will be described later. In a region from an
intermediate position of the coupling bolt 40 to an end portion on
the outer end side thereof, a plurality of (four in the present
embodiment) first drain flow paths D1 are formed in an elongated
hole shape (an example of a hole portion) with one end blocked
along the rotation axis X.
[0043] In the bolt body 41, a plurality of lock ports 41c (four in
the present embodiment) communicating with the lock control flow
path 35, a plurality of (four in the present embodiment) advance
ports 41a communicating with the advance flow path 33, and a
plurality of (four in the present embodiment) retard ports 41b
communicating with the retard flow path 34 are formed as through
holes connecting the internal space 40R and the outer peripheral
surface in order from the outer end side to the inner end side of
the coupling bolt 40 (see also FIG. 1). On an inner end side of the
retard port 41b of the bolt body 41, a plurality of (four in the
present embodiment) second drain flow paths D2 are formed as
through holes connecting the internal space 40R and the outer
peripheral surface, and communicate with the annular constriction
portion 41A. The annular constriction portion 41A communicates with
a drain communication path 5A formed through the end portion of the
intake camshaft 5, and the working oil from the second drain flow
path D2 is discharged to the outside through the drain
communication path 5A (see also FIG. 1). That is, in the present
embodiment, due to the configuration in which the first drain flow
path D1 extends in the rotation axis X direction and the second
drain flow path D2 extends in the radial direction orthogonal to
the rotation axis X direction, the first drain flow path D1 and the
second drain flow path D2 extend in directions intersecting each
other at different positions in the rotation axis X direction. The
drain communication path 5A may be formed at an end portion of the
internal rotor 30, or may be formed at a boundary position between
the internal rotor 30 and the intake camshaft 5.
[Valve Unit]
[0044] As shown in FIGS. 1 and 4, the valve unit Vb includes the
fluid supply pipe 54 that is coaxial with the rotation axis X and
is housed in the internal space 40R, and the spool 55 that is
freely slidable in the rotation axis X direction while being guided
by the inner peripheral surface of the coupling bolt 40 and an
outer peripheral surface of a pipeline portion 54T of the fluid
supply pipe 54. The valve unit Vb includes a spool spring 56 as a
biasing member that biases the spool 55 in the protrusion
direction, a check valve CV, an oil filter 59, and a fixing ring
60.
[0045] The fluid supply pipe 54 includes the pipeline portion 54T
inserted in the spool 55 and a flange-shaped base end portion 54S
at which the inner end side of the pipeline portion 54T is bent in
an annular shape. The pipeline portion 54T and the base end portion
54S are integrally formed. The base end portion 54S abuts on a
regulation step portion 41D provided at a boundary position on the
inner peripheral side between the male screw portion 41S and the
annular constriction portion 41A of the coupling bolt 40. In the
pipeline portion 54T, a plurality of (three in the present
embodiment) first supply ports 54a are formed near the base end
portion 54S, and a plurality of (three in the present embodiment)
second supply ports 54b are formed on the outer end side of the
first supply ports 54a.
[0046] The three first supply ports 54a are wide in the
circumferential direction and have an elongated hole shape
extending in the rotation axis X direction. Four intermediate hole
portions 55c formed in the spool 55 at positions corresponding to
the first supply ports 54a are circular. From such a configuration,
the working oil from the pipeline portion 54T can be reliably
supplied to the intermediate hole portions 55c.
[0047] Similar to the first supply ports 54a, the second supply
ports 54b also have an elongated hole shape extending in the
rotation axis X direction. Four end hole portions 55d formed in the
spool 55 at positions corresponding to the second supply ports 54b
are circular. From such a configuration, the working oil can be
reliably supplied from the pipeline portion 54T to the end hole
portions 55d.
[0048] The spool 55 is formed with a spool body 55a which is
tubular and has an abutting surface formed on the outer end side,
and four land portions 55b formed on the outer periphery thereof in
a protruding state. An internal flow path is formed inside the
spool 55. A plurality of (four in the present embodiment)
intermediate hole portions 55c communicating with the internal flow
path are formed at an intermediate position of the pair of land
portions 55b on an inner end side in the rotation axis X direction.
A plurality of (four in the present embodiment) end hole portions
55d communicating with the internal flow path are formed at the
intermediate position of the pair of land portions 55b on an outer
end side in the rotation axis X direction. An intermediate annular
groove 55f that does not communicate with the internal flow path is
formed at the intermediate position of the pair of land portions
55b between the intermediate hole portion 55c and the end hole
portion 55d. An elongated groove-shaped end annular groove 55g that
does not communicate with the internal flow path is formed on an
inner end side of the land portion 55b on an innermost end side in
the rotation axis X direction.
[0049] The spool 55 is formed with an abutting end portion 55r that
abuts on the base end portion 54S of the fluid supply pipe 54 to
determine an operation limit when the spool 55 is operated in a
pushing direction. The abutting end portion 55r is provided at an
end portion of a region where the spool body 55a is extended. Even
when the spool 55 is pushed in with an excessive force, a defect
that the spool 55 operates beyond the operation limit is
prevented.
[0050] The spool spring 56 is a compression coil type spring, and
is arranged between a bottom wall 55e on an outer end side of the
spool 55 and a bottom wall 54Ta on an outer end side of the
pipeline portion 54T of the fluid supply pipe 54. When the electric
power is not supplied to the solenoid portion 50 of the
electromagnetic unit Va due to an action of the biasing force, the
land portion 55b on the outer end side abuts on the regulation wall
44 and the spool 55 is maintained at a first advance position PA1
shown in FIG. 4.
[Check Valve]
[0051] The check valve CV includes an opening plate 57 and a valve
plate 58 which are formed of metal plates having an equal outer
diameter, a guide member 61, a tubular member 62, and a valve
spring 63. An annular opening portion 57a centered on the rotation
axis X is formed at an outer peripheral position of the opening
plate 57. A circular valve body 58a having a diameter larger than
that of the opening portion 57a is arranged at the outer peripheral
position of the valve plate 58, and a circular opening portion 58b
centered on the rotation axis X is formed at a center position.
[0052] The guide member 61 includes a bottom portion 61a and a
tubular protrusion portion 61b protruding from the bottom portion
61a. A plurality of slits 61ba are formed on a side wall of the
protrusion portion 61b. The protrusion portion 61b is inserted into
the opening portion 58b of the valve plate 58, and the valve plate
58 is guided by the protrusion portion 61b and moves. The tubular
member 62 includes a bottom portion 62a and an annular portion 62b
that protrudes annularly from an outer periphery of the bottom
portion 62a. An opening portion 62a1 having substantially the same
diameter as the inner diameter of the pipeline portion 54T of the
fluid supply pipe 54 is formed at the center of the bottom portion
62a. The opening plate 57, the valve plate 58, the guide member 61,
and the valve spring 63 are housed inside the annular portion 62b,
and the oil filter 59 abuts on the end portion of the annular
portion 62b.
[0053] The valve spring 63 is a compression coil type spring and is
arranged between the bottom portion 61a of the guide member 61 and
the valve body 58a of the valve plate 58. The check valve CV is
configured such that, when pressure downstream increases or when
discharge pressure of the hydraulic pump P decreases, the valve
body 58a comes into close contact with the opening plate 57 by the
biasing force of the valve spring 63 to close the opening portion
57a.
[0054] The oil filter 59 has a structure in which a metal net body
is reinforced with a resin frame, and removes dust contained in the
working oil. The fixing ring 60 is press-fitted and fixed to an
inner periphery of the end portion of the coupling bolt 40, and
positions of the oil filter 59, the opening plate 57, and the valve
plate 58 are determined by the fixing ring 60. The tubular member
62, the guide member 61, the valve spring 63, the opening plate 57,
and the valve plate 58 constituting the check valve CV are arranged
in this order, the oil filter 59 is arranged in the internal space
40R so as to be further overlapped, and the fixing ring 60 is
press-fitted and fixed to the inner periphery of the internal space
40R.
[0055] In this way, by fixing with the fixing ring 60, the base end
portion 54S of the fluid supply pipe 54 is sandwiched and fixed
between the bolt body 41 and the tubular member 62. Due to the
biasing force of the spool spring 56 that abuts on the bottom wall
54Ta of the fluid supply pipe 54, the land portion 55b on the outer
end side of the spool 55 abuts on the regulation wall 44, and a
position in the rotation axis X direction is determined.
[Operation Mode]
[0056] In the valve opening and closing timing control device A,
when the electric power is not supplied to the solenoid portion 50
of the electromagnetic unit Va, no pressing force acts on the spool
55 from the plunger 51, and a position of the spool 55 is
maintained in a state where the land portion 55b at the outer side
position abuts on the regulation wall 44 by the biasing force of
the spool spring 56 as shown in FIG. 4.
[0057] A movement start position of the spool 55 is the first
advance position PA1. By increasing the electric power supplied to
the solenoid portion 50 of the electromagnetic unit Va, as shown in
FIG. 3, the spool 55 can be freely operated to the second advance
position PA2, the neutral position PN, and the retard position PB
in this order. That is, by setting the electric power supplied to
the solenoid portion 50 of the electromagnetic unit Va, the spool
55 can be operated to any one of the four operation positions. When
the spool 55 is operated to the retard position PB, the spool 55 is
at the movement end position that maximizes the electric power
supplied to the solenoid portion 50.
[0058] Further, in the valve unit Vb, the first advance position
PA1 is set to a lock position. In this lock position, the lock
mechanism L can shift to the lock state. When the spool 55 is
operated to one of the first advance position PA1 and the second
advance position PA2, the working oil supplied from the hydraulic
pump P is sent to the advance port 41a through the intermediate
hole portion 55c of the spool 55, and is further supplied to the
advance chamber Ca from the advance flow path 33. At the same time,
the working oil in the retard chamber Cb flows from the retard flow
path 34 to the retard port 41b, and is discharged from the second
drain flow path D2 through the end annular groove 55g of the spool
55 to the outside through the annular constriction portion 41A and
the drain communication path 5A.
[0059] In the first advance position PA1, as shown in FIG. 4, in
cooperation with the supply of the working oil to the advance
chamber Ca and the discharge of the working oil from the retard
chamber Cb, the working oil in the lock recess 27 flows from the
lock control flow path 35 to the lock port 41c, and is discharged
from the first drain flow path D1 through the intermediate annular
groove 55f of the spool 55. As a result, when the vane portion 32
of the internal rotor 30 moves in the advance direction Sa and
reaches the intermediate lock phase M, the lock member 25 engages
with the lock recess 27 by the biasing force of the lock spring 26
to be in the lock state.
[0060] In the second advance position PA2, as shown in FIG. 5, in
cooperation with the supply of the working oil to the advance
chamber Ca, the working oil flows from the lock port 41c to the
lock recess 27 through the lock control flow path 35, and the
pressure of the working oil is applied to the lock member 25. As a
result, the operation in the advance direction Sa is continuously
performed in a state where the lock of the lock mechanism L is
released.
[0061] When the spool 55 is operated to the neutral position PN, as
shown in FIG. 6, the pair of land portions 55b are in such a
position relationship that the advance port 41a and the retard port
41b are closed, and the supply and discharge of the working oil to
the advance chamber Ca and the retard chamber Cb are cut off, and
the relative rotation phase is maintained. In the neutral position
PN, the working oil flows from the lock port 41c to the lock recess
27 through the lock control flow path 35, the pressure of the
working oil is applied to the lock member 25, and the state where
the lock of the lock mechanism L is released continues.
[0062] When the spool 55 is operated to the retard position PB, as
shown in FIG. 7, the working oil supplied from the hydraulic pump P
is sent to the retard port 41b through the intermediate hole
portion 55c of the spool 55, and is further supplied to the retard
chamber Cb from the retard flow path 34. At the same time, the
working oil in the advance chamber Ca flows from the advance flow
path 33 to the advance port 41a, and is discharged from the first
drain flow path D1 through the intermediate annular groove 55f of
the spool 55.
[0063] In this way, in any of the four operation positions, the
working oil of the lock mechanism L and the working oil of the
advance chamber Ca or the retard chamber Cb are not discharged to
the first drain flow path D1 at the same time, and the same applies
to the second drain flow path D2. Therefore, it is possible to
smoothly discharge the working oil from the lock mechanism L and to
reliably shift to the lock state. In addition, it is possible to
smoothly discharge the working oil from the advance chamber Ca or
the retard chamber Cb to improve the responsiveness of the phase
control.
[0064] In the present embodiment, the first drain flow path D1
through which the working oil is discharged from the advance
chamber Ca through the spool 55 and the second drain flow path D2
through which the working oil is discharged from the retard chamber
Cb through the spool 55 extend in directions intersecting each
other at different positions in the rotation axis X direction of
the coupling bolt 40. As a result, it is possible to sufficiently
ensure locations for providing the drain flow paths D1 and D2 on
the coupling bolt 40, and it is possible to increase a flow path
cross-sectional area of the first drain flow path D1 and the second
drain flow path D2. Therefore, the flow path cross-sectional area
of the drain flow paths D1 and D2 through which the working oil is
discharged from the advance chamber Ca or the retard chamber Cb can
be increased to improve the responsiveness of the phase control. In
addition, since the discharge of the working oil from the lock
mechanism L is also used in the first drain flow path D1, it is not
necessary to separately provide a lock drain flow path extending in
the rotation axis X direction of the coupling bolt 40, so that a
sufficient flow path cross-sectional area of the first drain flow
path D1 can be ensured.
[0065] Hereinafter, only a configuration different from the
above-described embodiment will be described as other embodiments.
In order to facilitate understanding of the drawings, the same
members as those in the embodiment described above are denoted by
the same reference numerals.
First Alternative Embodiment
[0066] As the lock mechanism L in the above-described embodiment, a
configuration that locks at a most advanced phase or a most
retarded phase may be adopted instead of the configuration that
locks at the intermediate lock phase M. An embodiment that locks at
the most retarded phase is shown in FIGS. 8 to 11. As shown in
FIGS. 8 and 10, a communication path 29 for communicating the lock
recess 27 and the advance chamber Ca is provided. Working oil is
supplied or discharged to the lock recess 27 through the
communication path 29 in cooperation with supply or discharge of
the working oil to the advance chamber Ca. In the present
embodiment, as in the above-described embodiment, the lock port 41c
of the bolt body 41 and the end hole portion 55d of the spool 55
are not provided so that an axial length of the valve opening and
closing timing control device A can be shortened to achieve a
compact size.
[0067] In the present embodiment, the spool 55 has three operation
positions (see FIG. 11). That is, a movement start position of the
spool 55 is an advance position PA. By increasing electric power
supplied to the solenoid portion 50 of the electromagnetic unit Va,
the spool 55 can be freely operated to the neutral position PN and
the retard position PB including a movement end position of the
spool 55 in this order.
[0068] In the advance position PA of the spool 55, in cooperation
with the supply of working oil to the advance chamber Ca, the
working oil supplied to the advance chamber Ca is also supplied to
the lock recess 27 through the communication path 29 (see FIGS. 8
and 10). At the same time, the working oil in the retard chamber Cb
flows from the retard flow path 34 to the retard port 41b, and is
discharged from the second drain flow path D2 through the end
annular groove 55g of the spool 55 to the outside through the
annular constriction portion 41A and the drain communication path
5A. As a result, the operation in the advance direction Sa is
continuously performed in a state where the lock of the lock
mechanism L is released. When the spool 55 is operated to the
neutral position PN, the supply and discharge of the working oil to
the advance chamber Ca and the lock recess 27 and the retard
chamber Cb are cut off, and the relative rotation phase is
maintained.
[0069] When the spool 55 is operated to the retard position PB, the
working oil is supplied to the retard chamber Cb, and in
cooperation with the discharge of the working oil from the advance
chamber Ca, the working oil in the lock recess 27 flows from the
advance flow path 33 to the advance port 41a through the
communication path 29, and is discharged from the first drain flow
path D1 through the intermediate annular groove 55f of the spool
55. As a result, when the vane portion 32 of the internal rotor 30
moves in the retard direction Sb and reaches the most retarded
phase, the lock member 25 engages with the lock recess 27 by the
biasing force of the lock spring 26 to be in the lock state (see
FIG. 10).
Second Alternative Embodiment
[0070] In the present embodiment, as shown in FIG. 9, a plurality
of drain grooves 55ba (an example of the outer end portion) are
formed on an outer surface of the land portion 55b on an outer end
side of the spool 55. The drain grooves 55ba communicate with the
intermediate annular groove 55f of the spool 55. That is, the first
drain flow path D1 in the first alternative embodiment is formed
between an outer end of the spool 55 including the drain groove
55ba and the bolt body 41. Similar to the embodiments described
above, the second drain flow path D2 in the present embodiment is
constituted by a through hole (through hole connecting the internal
space 40R of the bolt body 41 and the outer peripheral surface of
the bolt body 41) of the bolt body 41 in a direction intersecting
the rotation axis X direction.
[0071] Since the advance position PA and the neutral position PN of
the spool 55 are the same as those in the first alternative
embodiment, a description thereof will be omitted. When the spool
55 is operated to the retard position PB, the working oil is
supplied to the retard chamber Cb, and in cooperation with the
discharge of the working oil from the advance chamber Ca, the
working oil in the lock recess 27 flows from the advance flow path
33 to the advance port 41a through the communication path 29, and
is discharged from the first drain flow path D1 including the drain
groove 55ba through the intermediate annular groove 55f of the
spool 55. As a result, when the vane portion 32 of the internal
rotor 30 moves in the retard direction Sb and reaches the most
retarded phase, the lock member 25 engages with the lock recess 27
by the biasing force of the lock spring 26 to be in the lock
state.
Other Embodiments
[0072] (1) If the first drain flow path D1 and the second drain
flow path D2 in the above-described embodiments extend in
directions intersecting each other at different positions in the
rotation axis X direction, the first drain flow path D1 may be
inclined with respect to the rotation axis X direction, or the
second drain flow path D2 may be inclined with respect to the
radial direction.
[0073] (2) In the above-described embodiments, the bolt body 41 is
fixed to the intake camshaft 5 by screwing the male screw portion
41S formed on the bolt body 41 of the coupling bolt 40 as a tubular
valve case into the female screw portion 5S of the intake camshaft
5. Alternatively, for example, the valve unit Vb and the check
valve CV may be housed in the tubular valve case fixed to the
intake camshaft 5 by press-fitting or the like.
[0074] (3) The first advance position PA1 described above may be
set as the movement end position of the spool 55, and the retard
position PB may be set as the movement start position of the spool
55. When the retard position PB is the movement end position of the
spool 55, a lock mode may be provided in which, in cooperation with
the discharge of the working oil from the advance chamber Ca and
the supply of working oil to the retard chamber Cb, the working oil
of the lock recess 27 flows from the lock control flow path 35 to
the lock port 41c and is discharged from the first drain flow path
D1 through the intermediate annular groove 55f of the spool 55. In
this case, the working oil from the advance chamber Ca and the
working oil from the lock mechanism L are discharged from the first
drain flow path D1 at the same time. The spool 55 has five
operation positions in which a lock mode at the retard position is
added to the above four operation positions.
[0075] (4) The advance position PA in the first and second
alternative embodiments described above may be set as the movement
end position of the spool 55, and the retard position PB may be set
as the movement start position of the spool 55.
[0076] (5) As compared with the embodiments described above, the
valve unit Vb may be configured such that the arrangement of the
advance port 41a and the retard port 41b is reversed.
[0077] (6) In the embodiments described above, the first drain flow
path D1 may be constituted by a through hole of the coupling bolt
40 in a direction intersecting the rotation axis X direction.
[0078] (7) The lock mechanism L in the embodiments described above
can be restrained by any one of the intermediate lock phase M, the
most retarded phase, and the most advanced phase. Alternatively,
the lock mechanism L may be a multi-lock system capable of
restraining the relative rotation phase at a plurality of
phases.
INDUSTRIAL APPLICABILITY
[0079] Embodiments disclosed here can be used in a valve opening
and closing timing control device that controls a relative rotation
phase between a drive-side rotary body and a driven-side rotary
body by fluid pressure.
[0080] A characteristic configuration of a valve opening and
closing timing control device according to an aspect of this
disclosure resides in that the valve opening and closing timing
control device includes a drive-side rotary body that rotates
synchronously with a crankshaft of an internal combustion engine; a
driven-side rotary body that is provided inside the drive-side
rotary body in a state of being coaxial with a rotation axis of the
drive-side rotary body and that rotates integrally with a camshaft
for opening and closing a valve; an advance chamber and a retard
chamber formed between the drive-side rotary body and the
driven-side rotary body; a valve unit that includes a spool movable
in a rotation axis direction and that controls supply and discharge
of fluid to and from the advance chamber and the retard chamber; a
tubular valve case that has an internal space extending along the
rotation axis inside the driven-side rotary body in a radial
direction and that houses the valve unit in the internal space; a
first drain flow path through which the fluid is discharged from
any one of the advance chamber or the retard chamber through the
spool; and a second drain flow path through which the fluid is
discharged from the other one of the advance chamber or the retard
chamber through the spool, in which the first drain flow path and
the second drain flow path extend in directions intersecting each
other at different positions in the rotation axis direction.
[0081] In this configuration, since the valve unit is provided in
the internal space of the valve case in the rotation axis direction
inside the driven-side rotary body in the radial direction, the
device can achieve a compact size compared with a case where the
valve unit is provided outside the driven-side rotary body. When a
single spool is constituted as in the valve opening and closing
timing control device described in Reference 1 in order to achieve
a more compact size, a flow path configuration of the advance
chamber and the retard chamber are complicated. Accordingly, it is
important to ensure a flow path cross-sectional area of a phase
control drain flow path (advance chamber drain flow path and retard
chamber drain flow path) in order to improve the responsiveness of
the phase control.
[0082] Therefore, in this configuration, for example, the first
drain flow path through which the fluid is discharged from the
advance chamber through the spool and the second drain flow path
through which the fluid is discharged from the retard chamber
through the spool extend in directions intersecting each other at
different positions in the rotation axis X direction. As a result,
it is possible to sufficiently ensure locations for providing the
drain flow path, and it is possible to increase the flow path
cross-sectional area of the first drain flow path and the second
drain flow path. Therefore, it is possible to provide the valve
opening and closing timing control device capable of increasing the
flow path cross-sectional area of the drain flow path through which
the fluid is discharged from the advance chamber or the retard
chamber to improve the responsiveness of the phase control.
[0083] Another characteristic configuration resides in that, in the
valve case, the first drain flow path is formed to extend in the
rotation axis direction and the second drain flow path is formed to
extend in a radial direction orthogonal to the rotation axis
direction.
[0084] As in this configuration, in the valve case, when the first
drain flow path extends in the rotation axis direction and the
second drain flow path extends in the radial direction and both
drain flow paths are orthogonal to each other, the flow path
cross-sectional area of the first drain flow path and the second
drain flow path can be further ensured, and the valve case can be
easily processed.
[0085] Another characteristic configuration resides in that the
valve opening and closing timing control device includes a lock
mechanism that restrains a relative rotation phase of the
driven-side rotary body with respect to the drive-side rotary body
to an intermediate phase between a most retarded phase and a most
advanced phase, in which the fluid supplied to the lock mechanism
is discharged from the first drain flow path.
[0086] As in this configuration, the fluid discharge from the lock
mechanism is also used in the first drain flow path. Accordingly,
it is not necessary to separately provide a lock drain flow path
extending in the rotation axis direction of the valve case.
Therefore, a sufficient flow path cross-sectional area of the first
drain flow path can be ensured. Further, since it is possible to
discharge the fluid of the lock mechanism from the first drain flow
path while discharging the fluid of the advance chamber or the
retard chamber from the second drain flow path, shift to the
intermediate phase can be performed smoothly.
[0087] Another characteristic configuration resides in that the
valve opening and closing timing control device includes a lock
mechanism that restrains a relative rotation phase of the
driven-side rotary body with respect to the drive-side rotary body
to a most retarded phase or a most advanced phase, in which the
fluid supplied to the lock mechanism is discharged from the first
drain flow path.
[0088] As in this configuration, since the fluid discharge from the
lock mechanism is also used in the first drain flow path, it is not
necessary to separately provide a lock drain flow path extending in
the rotation axis direction of the valve case. Therefore, a
sufficient flow path cross-sectional area of the first drain flow
path can be ensured.
[0089] Another characteristic configuration resides in that the
second drain flow path includes a through hole of the valve case
along a direction intersecting the rotation axis direction.
[0090] Since the second drain flow path in this configuration is
constituted by the through hole of the valve case in the direction
intersecting the rotation axis direction, the flow path
cross-sectional area can be sufficiently ensured.
[0091] Another characteristic configuration resides in that the
first drain flow path includes a hole portion along the rotation
axis direction of the valve case.
[0092] As in this configuration, if the first drain flow path is
constituted by the hole portion in the rotation axis direction of
the valve case, the size of the hole portion may be changed
according to a required flow path cross-sectional area, and the
flow path can be easily designed.
[0093] Another feature configuration resides in that the first
drain flow path is formed between an outer end portion of the spool
and the valve case.
[0094] As in this configuration, if the first drain flow path is
formed between the outer end portion of the spool and the valve
case, processing is easier than when the first drain flow path is
formed in the rotation axis direction of the valve case.
[0095] Another characteristic configuration resides in that, when
the spool is at one of a movement start position or a movement end
position, the fluid is discharged from the first drain flow path,
and when the spool is at the other one of the movement start
position or the movement end position, the fluid is discharged from
the second drain flow path.
[0096] As in this configuration, if the first drain flow path and
the second drain flow path are provided when the spool is at the
movement start position and movement end position, positions of the
phase control drain flow path can be easily set.
[0097] 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.
* * * * *