Information
-
Patent Grant
-
6374786
-
Patent Number
6,374,786
-
Date Filed
Thursday, September 21, 200023 years ago
-
Date Issued
Tuesday, April 23, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 123 9015
- 123 9017
- 123 9031
- 074 568 R
- 464 1
- 464 2
- 464 60
-
International Classifications
-
Abstract
A valve timing controller with the structure of a stopper mechanism and a lock mechanism thereof is so provided as to reduce the cost and the size of the controller. The valve timing controller comprises a stopper mechanism and a lock mechanism including a lock member assembled with a housing member and a tip portion of the lock member which is always projecting towards a rotor member, a free recess portion formed on the rotor member and accommodating the tip portion of the lock member while allowing the relative rotation of the housing member and the rotor member, a stopper surface formed on one end surface in circumferential direction of the free recess portion and defining a initial phase by the contact with the tip portion of the lock member, a lock recess portion formed continuously along the stopper surface and being capable of accommodating the tip portion of the lock member by restricting the movement thereof in circumferential direction at an initial phase, and a lock spring biasing the lock member towards the lock recess portion.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a valve timing controller and, more particularly, to a valve timing controller for controlling the valve timing of an intake valve and an exhaust valve for a valve train of an internal combustion engine.
2. Description of the Related Arts
A prior art of the valve timing controller of this kind is disclosed in Japan Patent Laid-open Publication H09-60508 (published on Mar. 4, 1997). In this prior art, the valve timing controller is disposed in the driving force transmitting system transmitting the driving force from the drive shaft of an internal combustion engine (a crankshaft of the engine) to the driven shaft (camshaft) opening and closing either an intake valve or an exhaust valve of the internal combustion engine. The valve timing controller in this prior art comprises a housing member rotating in one unit with the drive shaft (or the driven shaft), a rotor member assembled at a pair of shoe portions provided in the housing member for relative rotation therewith at a hub portion, forming an advance angle fluid chamber and a retard angle fluid chamber at a vane portion, and rotating in one unit with the driven shaft (or the drive shaft), a stopper mechanism defining the initial phase of the housing member and the rotor member, a lock mechanism defining the relative rotation of the housing member and the rotor member at the initial phase, and a hydraulic pressure circuit controlling the supply and exhaust of the operation fluid to the advance angle fluid chamber and the retard angle fluid chamber and controlling the lock/unlock of the lock mechanism.
In the valve timing controller of above mentioned prior art, a stopper mechanism is adopted which includes a stopper surface provided on the circumferential direction end of the shoe portion (the portion rotatably supporting the rotor member) of the housing member and a contacting surface provided on the circumferential direction end of the vane portion (the portion forming the advance angle fluid chamber and the retard angle fluid chamber with the shoe portion) of the rotor member. The initial phase of the housing member and the rotor member is defined by the contact between the stopper surface and the contacting surface.
The lock mechanism of above-mentioned prior art comprises a piston assembled slidably in axial direction of the camshaft in an accommodation hole disposed in the vane portion of the rotor member and having a tip end tapered off, a tapered hole disposed in the housing member and being capable of tapered fitting with the tip portion of the piston at the initial phase of the housing member and the rotor member, and a spring biasing the piston towards the tapered hole. By tapered fitting of the tip of the piston and the tapered hole at the initial phase of the housing member and the rotor member, the relative rotation between the housing member and the rotor member is restricted and the relative rotation between the housing member and the rotor member is allowed under the condition that the tip portion of the piston is separated or retrieved from the tapered hole.
However, the valve timing controller of the prior art has the following disadvantages: Since the contacting surface (the end surface in circumferential direction) provided on the vane portion of the rotor member contacts the stopper surface (the end surface in circumferential direction) provided on the shoe portion of the housing member, high precision machining is required on the end surface in circumferential direction of the shoe portion of the housing member and on the end surface in circumferential direction of the vane portion of the rotor member. The vane portion of the rotor member and the shoe portion of the housing member are required to have enough strength to bear against the load at contacting.
Having the initial phase of the housing member and the rotor member as a standard, that is, for the manufacturing precision of the stopper surface formed on the shoe portion of the housing member and of the contacting surface formed on the vane portion of the rotor member, severe tolerance of the relative position between the tip portion of the piston and the tapered hole is required (Since the piston is a separated member from the member formed with the contacting surface and the stopper surface and the tapered fitting portion is provided at the different location from the contacting portion of the stopper surface and the contacting portion, it is very difficult to satisfy the highly required precision). Since the relative rotation of the housing member and the rotor member is allowed when the tip portion of the piston is separated or retrieved from the tapered hole, in the case the external materials entered into the tip portion of the piston which has been separated from the tapered hole (since the tip portion of the piston is tapered off, a large gap is generated between the piston and the accommodation hole, and the external materials is easy to be entered), such external materials tend to be trapped between the tip portion of the piston (tapered tip end portion) and the accommodation hole.
SUMMARY OF THE INVENTION
Accordingly, an object of the valve timing controller of the invention is to reduce the size, improve the productivity and achieve reliable operation.
To solve the aforementioned problems the following technical means is provided with a valve timing of the invention provided on the driving force transmitting system transmitting the driving force to the driven shaft opening and closing either intake valve or an exhaust valve of an internal combustion from the drive shaft of the internal combustion engine, a housing member rotatable in one unit with the drive shaft (or the driven shaft), a rotor member rotatably assembled with a pair of shoe portions provided on the housing member, forming an advance angle fluid chamber and a retard angle fluid chamber at a vane portion, and rotating in one unit with the driven shaft (or the drive shaft), a stopper mechanism defining the initial phase of the housing member and the rotor member, a lock mechanism restricting the relative rotation of the housing member and the rotor member at the initial phase, and a hydraulic pressure circuit controlling the supply and exhaust of the operation fluid to the advance angle fluid chamber and the retard angle fluid chamber and controlling the lock/unlock of the lock mechanism. The stopper mechanism and the lock mechanism include a lock member slidably assembled with the housing member (or the rotor member) and the tip portion of the lock member which is always projecting towards the rotor member (or the housing member), a free recess portion formed in the rotor member (or the housing member) and accommodating the tip portion of the lock member while allowing the relative rotation of the housing member and the rotor member, a stopper surface formed on the end surface in circumferential direction of the free recess portion and defining the initial phase by the contact with the tip portion of the lock member, a lock recess portion formed continuously along the stopper surface and being capable of accommodating the tip portion of the lock member with restricting the movement thereof in circumferential direction at the initial phase, and a lock spring biasing the lock member towards the lock recess portion.
In this case, it is desirable to form a second stopper surface limiting the maximum relative rotation of the rotor member relative to the housing member on the other end surface in the circumferential of the free recess portion opposite to the stopper surface.
The valve timing of the invention includes a first rotation body opening and closing either the intake valve or the exhaust valve of the internal combustion engine, a second rotation body rotating in one unit with the drive shaft of the internal combustion engine and transmitting the driving force from the drive shaft to the first rotation body, a phase change controlling means changing the phase of the first rotation body either to the advance angle side or to the retard angle side relative to the second rotation body, and a restricting means including a stopper mechanism regulating the rotational amount of the first rotation body relative to the second rotation body at least to either side of the advance angle side and the retard angle side and a lock mechanism restricting the relative rotation of the first rotation body and the second rotation body. The stopper mechanism and the lock mechanism of the restricting means are formed in one unit.
In this case, the first rotation body and the second rotation body are coaxially arranged. It is desirable that the restricting means is comprised of a lock member rotatably and slidably disposed on one of the first rotation body and the second rotation body, the free recess portion provided on the other of the first rotation body and the second rotation body and accommodating the lock member while allowing the relative rotation of the first rotation body and the second rotation body, the stopper surface provided on one end surface in circumferential direction of the free recess portion and restricting the rotation of the first rotation body relative to the second rotation body in either direction of the advance angle side and the retard angle side by being connected to the lock member, the lock recess portion provided continuously along the stopper surface and being capable of accommodating the lock member to restrict the relative rotation between the first rotation body and the second rotation body, and a biasing means always biasing the lock member towards the lock recess portion.
The effects of the technical means in the invention of the valve timing are as follows. Since the stopper mechanism and the lock mechanism including the lock member, the free recess portion, the stopper surface, the lock recess portion, and the lock spring are provided on the housing member and the rotor member, machining on the end surface in circumferential direction of the shoe portion of the housing member and on the end surface in circumferential direction of the vane portion of the rotor member is not required, and the vane portion of the rotor member and the shoe portion of the housing member are not required to have an excess strength. Accordingly, the manufacturing cost can be reduced and the size of the valve timing controller can be reduced by making thinner vane portion of the rotor member.
Since the stopper surface defining the initial phase, by the contact with the tip portion of the lock member is formed on one end in circumferential direction of the free recess portion and the lock recess portion is formed continuously along the stopper surface (since the stopper surface and the lock recess portion are formed at one place on the same member), severe tolerance of the relative position of the lock recess portion relative to the initial phase can be easily achieved. Accordingly, the productivity of the valve timing controller of the invention can be improved.
Since the tip portion of the lock member which is always projecting and a small gap will be sufficient for allowing the sliding movement between the lock member and the housing member (or rotor member) slidably supporting the lock member, the external materials rarely enter into the gap, and the entrapment of the external materials can be prevented. This improves the locking operation reliability of the lock member.
When the second stopper surface restricting the maximum relative rotational amount of the rotor member relative to the housing member is formed on the other end surface in circumferential direction of the free recess portion opposite to the stopper surface at the practical use of the invention, the maximum rotational amount of the rotor member relative to the housing member can be precisely and easily set by precisely forming the length in circumferential direction of the free recess portion.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the invention will be more apparent and more readily appreciated from the following detailed description of the preferred embodiments of the invention with the accompanying drawings, in which;
FIG. 1
is a cross-sectional view (taken on line
1
—
1
of
FIG. 3
) of an embodiment of a valve timing controller in accordance with the present invention
FIG. 2
is a front view of the valve timing controller shown in
FIG. 1
;
FIG. 3
is a back view of the valve timing controller shown in
FIG. 1
;
FIG. 4
is a cross-sectional view taken on line
4
—
4
of a sprocket shown in
FIG. 1
;
FIG. 5
is a cross-sectional view taken on line
5
—
5
of the sprocket and a front rotor shown in
FIG. 1
;
FIG. 6
is a cross-sectional view taken on line
6
—
6
of the sprocket shown in
FIG. 1
; and
FIG. 7
is a cross-sectional view taken on line
7
—
7
of FIG.
1
.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of a valve timing controller of the invention will be described as follows referring to
FIGS. 1 through 7
. The valve timing controller of the invention illustrated in
FIGS. 1 through 7
includes a rotor member
20
(a first rotation body) assembled on a tip portion of a camshaft in one unit therewith, a housing member
30
(a second rotation body) outfitted with the rotor
20
for relative rotation within a predetermined range, torsion springs disposed between the housing member
30
and the rotor member
20
and always biasing the rotor member
20
to the housing member
30
in advance angle side, a stopper mechanism A regulating an initial phase (the most retarded angle position) and the most advanced angle position of the housing member
30
and the rotor member
20
, a lock mechanism B restricting the relative rotation between the housing member
30
and the rotor member
20
at the initial phase, and a hydraulic circuit C controlling supply and exhaust of the operation fluid to an advance angle fluid chamber R
1
and a retard angle fluid chamber R
2
and controlling locking and unlocking of the lock mechanism B.
The camshaft
10
having a conventional cam mechanism which opens and closes an intake valve is rotatably supported by a cylinder head
40
of the internal combustion engine and wherein an advance angle conduit
11
and a retard angle conduit
12
extending in axial direction of the camshaft
10
are disposed therein. The advance angle conduit
11
is connected to a connecting port
101
of a switching valve
100
via a conduit
13
in radial direction, an annular conduit
14
, and a connecting conduit P
1
. The retard angle conduit
12
is connected to a connecting port
102
of the switching valve
100
via a conduit
15
in radial direction, an annular conduit
16
, and a connecting conduit P
2
. The conduit
13
,
15
in radial direction and the annular conduit
16
are formed in the camshaft
10
. The annular conduit
14
is formed between the stepped portion of the camshaft
10
and the cylinder head
40
.
The switching valve
100
comprises the hydraulic circuit C with an oil pump
110
and a reservoir
120
and is capable of moving a spool
104
in left direction of
FIG. 1
against a biasing force of a spring
105
by energizing a solenoid
103
.
When the solenoid valve
103
is de-energized, a supply port
106
connected to the oil pump
110
actuated by the internal combustion engine is in communication with the connecting port
102
and the connecting port
101
is in communication with an exhaust port
107
connected to the reservoir
120
. When a first predetermined current is applied, the supply port
106
and the exhaust port
107
are disconnected from the connecting port
101
and the connecting port
102
respectively. When a second predetermined current (larger than the first predetermined current) is applied, the supply port is in communication with the connecting port
101
and the connecting port
102
is in communication with the exhaust port
107
.
Accordingly, at the de-energized condition of the solenoid
103
, the operation fluid from the oil pump
110
is supplied to the retard angle conduit
12
and the operation fluid is exhausted from the advance angle conduit
11
to the reservoir
120
. At the energized condition of the first predetermined current, the operation fluid is reserved in the advance angle conduit
11
and the retard angle conduit
12
. At the energized condition of the second predetermined current, the operation fluid from the oil pump
110
is supplied to the advance angle conduit
11
and the operation fluid is exhausted from the retard angle conduit
12
to the reservoir
120
.
The rotor member
20
is comprised of a main rotor
21
, stepped cylindrical front rotor
22
assembled in one unit on the front and the back (on the left and right in
FIG. 1
) of the main rotor
21
, and a stepped cylindrical rear rotor
23
(a connecting member and a projecting portion). The rotor member
20
is secured in one unit to the front end of the camshaft
10
with a bolt
50
. Central inner holes of respective rotors
21
,
22
, and
23
are closed at their front ends by the head portion of the bolt
50
and in communication with the advance angle conduit
11
provided in the camshaft.
The main rotor
21
includes a hub portion
21
a
to which the front and rear rotors
22
,
23
are coaxially assembled. The main rotor
21
further includes four vane portions
21
b,
four advance angle fluid conduits R
1
and four retard fluid conduits R
2
extending outwardly in radial direction from the hub portion
21
a
and defining therein. A sealing member
24
sealing between the advance angle fluid chamber R
1
and the retard angle fluid chamber R
2
is assembled on the outer end in radial direction of each vane portion
21
b.
The hub portion
21
a
of the main rotor
21
includes four radically extended conduits
21
c
communicating with the advance angle fluid conduit R
1
at the outer end in radial direction and with the advance angle conduit
11
via the central inner holes at inner end in radial direction, four conduits
21
d
extended in axial direction communicating with the retard angle conduit
12
, and four radial conduits
21
e
communicating with the retard angle fluid chamber R
2
at the outer end in radial direction.
Two opposing conduits
21
d
extended in axial direction of the four (those shown on the top left and the bottom right in
FIGS. 4 through 6
) are penetrated into the main rotor
21
in axial direction, communicating with the retard angle conduit
12
via a conduit
23
a
extended in axial direction and an annular conduit
23
b
(refer to FIG.
1
and
FIG. 3
) disposed in the rear rotor
23
. The other pair of opposing conduits
21
d
extended in axial direction (shown on the top right and the bottom left in
FIGS. 4 through 6
) are opening only to the front side of the main rotor
21
and are communicated with the conduits
21
d
penetrated in axial direction through a pair of arc shaped communicating grooves
22
a
(refer to FIG.
1
and
FIG. 5
) formed on the back of the front rotor
22
. A hole
21
f
in axial direction shown in
FIG. 4 through 6
is formed for inserting a pin (not shown) connecting the main rotor
21
and the front rotor
22
.
The housing member
30
comprises a housing body
31
, a front plate
32
, a rear thin plate
33
, a rear thick plate
34
, and four bolts
35
connecting those components in one unit. A sprocket
34
a
is formed in one unit on a periphery of the rear thick plate
34
. The sprocket
34
a
is connected to a crankshaft (not shown) of the internal combustion engine via timing chain (not shown) and is structured to transmit the driving force from the crankshaft.
The housing body
31
includes two pairs of (four) shoe portions
31
a
projecting inwardly in radial direction and supporting the hub portion
21
a
of the main rotor
21
for relative rotation via a sealing portion
36
at inner end in radial direction of each shoe portion
31
a.
The front plate
32
and the rear thin plate
33
slidably contact the outer periphery of the end surface in axial direction of the hub portion
21
a,
the entire end surface in axial direction of each vane portion
21
b,
and the entire end surface in axial direction of each sealing portion member
36
.
In the housing member
30
, an accommodation portion accommodating the rotor member
20
having cylindrical shape with the bottom opening in the rear direction (right direction in
FIG. 1
) is formed with housing body
31
and the front plate
32
. A cover portion for covering the opening portion of the accommodation portion is formed with the rear thin plate
33
and the rear thick plate
34
.
As shown in FIG.
1
and
FIG. 7
, the rear thick plate
34
(drive force transmitting means) includes an accommodation groove
34
b
in a hub portion
34
c.
The accommodation groove
34
b
is opened to the front side of the main rotor
21
and inwardly in radial direction and the opening of the front side is closed by the rear thin plate
33
(only the inner periphery brim) is illustrated with an imaginary line in FIG.
7
).
The accommodation groove
34
b
is relatively rotatably supported on the periphery of the rear rotor
23
projecting from the opening portion of the housing member
30
at the inner periphery of the hub portion
34
c.
In the accommodation groove
34
b,
a lock key
61
(restricting means) and a lock spring
62
are assembled rotatably in one unit to the rear thick plate
34
.
The lock key
61
formed in rectangular shape in cross section has a sufficient length such that the tip portion
61
a
protrudes from the accommodation groove
34
b
when the key
61
moves until it contacts the outer end in radial direction of the accommodation groove
34
b,
wherein the tip portion
61
a
is normally projecting towards a free recess portion
23
d
formed on the outer periphery of the hub portion
23
c
of the rear rotor
23
. On the outward portion (in radial direction) of the lock key
61
, a groove
61
b
accommodating a portion of a lock spring
62
is formed. The groove
61
b
is opened to front side of the main rotor
21
and outwardly in radial direction. Since the outer end in radial direction of the accommodation groove
34
b
is opened through a hole
34
d,
the swift move of the lock key
61
in radial direction is ensured.
The arc shaped free recess portion
23
d
extending in the circumferential direction accommodates the tip portion
61
a
of the lock key
61
while allowing the relative rotation of the housing member
30
and the rotor member
20
. A stopper surface
23
e
defining the initial phase (most retarded angle position) by the contact of the lock key
61
and the tip portion
61
a
is formed in circumferential direction on one end of the free recess portion
23
d.
A lock recess portion
23
f
is formed continuously along the stopper surface
23
e.
The lock spring
62
always biases the lock key
61
towards the bottom of the free recess portion
23
d,
i.e., the radically inward direction of the rear thick plate
34
. Accordingly, the lock key
61
is slidable in the direction of the accommodation in the free recess portion
23
d
(the radial direction of the rear thick plate
34
) at the rear thick plate
34
.
As shown in
FIG. 7
the lock recess
23
f
is capable of accommodating the tip portion
61
a
of the lock key
61
to be locked therein along the circumferential direction at the initial phase. A hole
23
h
extended in radial direction and communicating with the advance angle conduit
11
at the inner end in radial direction is opened on the bottom portion of the lock recess portion
23
f.
When the operation fluid is supplied from the advance angle conduit
11
via a hole
23
h,
the lock key
61
is moved to the position shown with the imaginary line of
FIG. 7
against the biasing force of the lock spring
62
outwardly in radial direction. When the operation fluid is exhausted to the advance angle conduit
11
via the hole
23
h,
the lock key
61
is moved to the lock recess
23
f
by the biasing of the lock spring
62
, the tip portion
61
a
of the lock key
61
is engaged with the lock recess
23
f
and accommodated.
In one embodiment with above-mentioned structure, as shown in
FIG. 7
, the lock key
61
is engaged with the lock recess portion
23
f
by the biasing force of the lock spring
62
and is accommodated when the operation fluid is not supplied to the advance angle conduit
11
and the retard angle conduit
12
from the oil pump
110
actuated by the starting of the internal combustion engine via the switching valve
100
.
Accordingly, even if the positive and negative reverse torque is generated in the camshaft
10
when actuating the intake valve, since the lock key
61
restricts the relative rotation of the rotor member
20
to the housing member
30
, relative rotational vibration is not generated and the noise generated accompanied with the rotational vibration is prevented. When the switching valve
100
is under de-energized condition as shown in
FIG. 1
at the starting of the internal combustion engine, the operation fluid is supplied from the oil pump
110
to the retard angle conduit
12
via the switching valve
100
, and at the point when the operation fluid is introduced to the retard angle fluid chamber R
2
, the relative rotation of the rotor member
20
and the housing member
30
is regulated by the hydraulic pressure in the retard angle fluid chamber R
2
as well.
When the solenoid
103
of the switching valve
100
is switched from de-energized condition to energized condition of a second predetermined current, the supply port
106
communicates with the connecting port
101
, the connecting port
102
communicates with the exhaust port
107
, the operation fluid is supplied to the advance angle conduit
11
, and the operation fluid is discharged from the retard angle conduit
12
to the reservoir
120
. Accordingly, the operation fluid is supplied to the lock recess portion
23
f
from the advance angle conduit
11
through the hole
23
h
of the rear rotor
23
, the operation fluid is supplied to the advance angle fluid chamber R
1
from the advance angle conduit
11
via the conduit
21
c
of the main rotor
21
, and the operation fluid is exhausted from the retard angle fluid chamber R
2
to the retard angle conduit
12
via the conduit
21
e
and the conduit
21
d
of the main rotor
21
.
In consequence, the lock key
61
is moved clockwise from the position with actual line to the position with the imaginary line of
FIG. 7
against the biasing force of the lock spring
62
by the operation fluid supplied to the lock recess portion
23
f.
The rotor member
20
is moved clockwise in
FIG. 4
by the operation fluid supplied to the advance angle fluid chamber RI and rotates from the most retarded angle position to the advance angle side relative to the housing member
30
. The relative rotation between the rotor member
20
and the housing member
30
is possible until the second stopper surface
23
g
formed on the rear rotor
23
and the tip portion
61
a
of the lock key
61
make a contact.
When the solenoid
103
of the switching valve
100
is switched from energized condition of the second predetermined current to energized condition of the first predetermined current, the fluid communication between the supply port
106
, exhaust port
107
and each connecting port
101
,
102
is blocked respectively and the operation fluid is reserved in the advance angle conduit
11
and the retard angle conduit
12
. Via the reserve of the operation fluid in the advance angle conduit
11
and the retard angle conduit
12
(also recognized as the condition that the operation fluid is reserved in the advance angle fluid chamber R
1
and the retard angle fluid chamber R
2
), the relative rotation of the rotor member
20
to the housing member
30
is regulated.
When the solenoid
103
of the switching valve
100
is switched from energized condition of the first predetermined current to de-energized condition, the supply port
106
communicates with the connecting port
102
, the connecting port
141
communicates with the exhaust port
107
, the operation fluid is supplied to the retard angle conduit
12
, and the operation fluid is exhausted from the advance angle conduit
11
to the oil reservoir
120
. Consequently, the operation fluid is supplied from the retard angle conduit
12
the retard angle fluid chamber R
2
through the conduit
21
d
and the conduit
21
e
of the main rotor
21
and the operation fluid is discharged from the advance angle fluid chamber R
1
to the advance angle conduit
11
through the conduit
21
c
of the main rotor.
Accordingly, the rotor member
20
is moved in counterclockwise direction of
FIG. 4
by the operation fluid supplied to the retard angle fluid chamber R
2
to relatively rotate in the retard angle direction relative to the housing member
30
. The relative rotation of the rotor member
20
to the housing member
30
is possible until the tip portion
61
a contacts the stopper surface
23
e.
In this case, since the operation fluid can be exhausted from the lock recess portion
23
f
to the advance angle conduit
11
, when the rotor member
20
rotates relative to the housing member
30
, until reaching the most retarded angle position (where the stopper surface
23
e
formed on the rear rotor
23
and the tip portion
61
a
of the lock key
61
contact) after the lock key
61
has been moved by the biasing force of the lock spring
62
and the tip portion
61
has engaged with the lock recess portion
23
f
to be accommodated.
Apparent from the explanation above, in this embodiment of the invention, the position of the relative rotation of the rotor member
20
to the hosing member
30
is freely adjustable in the range from the most retarded angle position to the most advance angle position by controlling the energized condition to the solenoid
103
of the switching valve
100
and the timing for opening and closing the valve when actuating the internal combustion engine is properly adjustable. When the internal combustion engine is stopped, the energized condition to the solenoid
103
is controlled so that the tip portion
61
a
of the lock key
61
b
is engaged with the rock recess portion
23
f
and accommodated.
In another embodiment of the invention, a phase controlling means is structured with the hydraulic pressure circuit C, the advance angle fluid chamber R
1
and the retard angle fluid chamber R
2
formed between the housing member
30
and the rotor member
20
, the hydraulic pressure conduit communicating with the advance angle fluid chamber R
1
, the retard angle fluid chamber R
2
, and the hydraulic pressure circuit C, and the vanes
21
b
formed in the rotor member
20
and receiving the pressure from the advance angle fluid chamber R
1
and the retard angle fluid chamber R
2
.
In another embodiment of the invention, the stopper mechanism A and the stopper mechanism B are disposed on each hub portion of the housing member
30
and the rotor member
20
. The stopper mechanism A includes the lock key
61
, the free recess portion
23
d,
the stopper surface
23
e,
23
g.
The stopper mechanism B includes the lock key
61
, the rock recess portion
23
f,
and the lock spring
62
.
Sharing the lock key
61
between the stopper mechanism A and the stopper mechanism B enables to structure the stopper mechanism A and the stopper mechanism B in one unit, which, consequently, reduces the size of the device. In particular, the sharing eliminates the need for machining on the end surface in circumferential direction of the shoe portion
31
a
of the housing member
30
and on the end surface in circumferential direction of the vane portion
21
b
of the rotor member
20
. As such, the strength of the vane portion
21
b
and the shoe portion
31
a
is not strictly required so that they can be made thin, which reduces the manufacturing cost and size of the device.
Since the stopper surface
23
e
regulating the initial phase (by the contact with the tip portion
61
a
of the lock key
61
) is formed on one end in circumferential direction of the free recess portion
23
d
and the lock recess portion
23
f
is formed continuously along the stopper surface
23
e
(since the stopper surface
23
e
and the lock recess portion
23
f
are formed on the same position of the rear rotor
23
), strict tolerance of the relative position of the lock recess portion
23
f
at the initial phase can be easily obtained. Accordingly, the efficiency of the device is improved.
The tip portion
61
a
of the lock key
61
is normally projecting as shown with the actual line and the imaginary line in
FIG. 7. A
small gap for allowing the sliding can be provided between the lock key
61
and the housing member
30
(rear thin plate
33
and the rear thick plate
34
) slidably supporting thereof. Since external materials rarely enter this gap and the entrapment of the external materials can be prevented, the operation reliability of the lock key
61
can be improved.
Since the second stopper surface
23
g
regulating the maximum relative rotational amount of the rotor member
20
to the housing member
30
is formed on the other end in circumferential direction of the free recess portion
23
d
opposite to the stopper surface
23
e,
the maximum relative rotational amount of the rotor member
20
to the housing member
30
is easily set by forming the precise length in peripheral direction of the free recess portion
23
d.
Since the maximum relative rotational amount can be set by changing the length in peripheral direction of the free recess portion
23
d
disposed on the rear rotor
23
, the valve timing control device adapted to various models of vehicles can be produced by changing the rear rotor
23
and the other parts (the components for the rotor member
20
except the rear rotor
23
and the components for the housing member
30
) can be platformed.
The conventional valve timing controller, as shown in the aforementioned prior art Japan Patent Laid-open Publication H09-60508, has a lock mechanism structured with a piston slidably disposed in the accommodation hole on the vane portion, tapered hole formed on a housing member connected to the piston, and a spring biasing the piston towards the tapered hole. In other word, the conventional lock mechanism is disposed in the accommodation portion of the housing. The vane portion disposed with a piston in the conventional valve timing controller is required to be formed wider in peripheral direction than the vane portion without the piston as in the invention. Accordingly, the rotor member is imbalanced. In addition, since the tapered hole is formed on the housing member, the housing member is also imbalance. The imbalance of the rotor member and the housing impedes the smooth and swift rotation of the rotor member and the housing member, which consequentially impedes the phase control of the valve timing controller.
For dissolving above mentioned imbalance, for example, the imbalance at the vane portion, it is considered to balance with symmetrical vane portion at the rotation axis. Changes of the structure, such as adding the mass on the symmetrical vane portion, which generates the increase of the mass of the device and the restriction of maximum angle of the phase change, achieves such a balancing.
On the other hand, in the valve timing controller of this embodiment of the invention, the lock mechanism is disposed outside of the accommodation portion of the housing member
30
, that is in the rear thick plate
34
and the rear rotor
23
. In this structure, although the imbalance is generated between the rear thick plate
34
and the rear rotor
23
, the imbalance is solved by machining the rear plate
34
and the rear rotor
23
which is thinner than the vane portion. Since the parts symmetrical to the rotation axis of the part disposed with the lock key
62
exists on the rear thick plate
34
and the rear rotor
23
, the balance is easily achieved by machining such symmetrical parts. This improves the efficiency of the machining compared to the one with conventional structure. In this structure, the balancing is not restricted by the provided number of the vane portion
21
b.
In another embodiment of the invention, the valve timing controller being capable of solving the rotation imbalance easier than the conventional valve timing controller is provided. This valve timing controller includes the rotor provided in one unit with the camshaft opening or closing at least one of the intake valve or the exhaust valve of the internal combustion engine, the housing rotatably and coaxially disposed relative to the rotor and transmitting the driving force of the drive shaft to the rotor by being rotated in one unit with the drive shaft of the internal combustion engine, the phase change controlling means changing the phase of the rotor from the advance angle side to the retard angle side relative to the housing. The housing includes the accommodation portion with cylindrical shape with the bottom accommodating the rotor, the cover portion covering the opening of the accommodation portion, and the lock mechanism a portion of the structure thereof is disposed outside of the accommodation portion and regulating the relative rotation between the rotor and the housing. In this case, the cover portion is flat plate shaped and at least part of the lock mechanism is formed in the cover portion. The rotor includes the projecting portion projecting from the opening. The lock mechanism includes the restricting means regulating the relative rotation between the rotor and the housing by being connected to the cover portion and the projecting portion.
The aforementioned conventional valve timing controller includes a rotor in one unit with the camshaft opening and closing one of the intake valve and the exhaust valve of the internal combustion engine, a timing sprocket rotating in one unit with the drive shaft of the internal combustion engine and transmitting the driving force from the drive shaft to the rotor, and the phase controlling means changing the phase of the rotor to the advance angle side or to the retard angle side relative to the timing sprocket. The timing sprocket is rotatably supported by the camshaft.
Generally, the shape of the camshaft depends on the model of an automobile provided with the device. Accordingly, in conventional valve timing controller, the different timing sprocket is required to be formed for different models, which impedes the production efficiency of the device.
However, in this embodiment of the invention, since the rear thick plate
34
is rotatably supported by the rear rotor
23
, only the rear rotor
23
is required to be changed even when applying the valve timing controller to vehicle models with camshafts of different shapes. Since the rear rotor is easily formed compared to the rear thick plate
34
, the production efficiency of the device is improved. This valve timing controller of the invention includes the rotor disposed in one unit with the camshaft rotating in an intake valve or an exhaust valve of an internal combustion engine, the driving force transmitting means rotating in one unit with the drive shaft of the internal combustion engine and transmitting the driving force of the drive shaft to the rotor, the phase change controlling means changing phase of the rotor to the advance angle side or to the retard angle side relative to the driving force transmitting means, and the connecting member provided between the rotor and the camshaft, rotatably supporting the driving force transmitting means and connecting the rotor and the camshaft.
Besides being applied to the camshaft
100
for opening and closing the intake valve of the internal combustion engine, the valve timing controller of the invention may be applied to the camshaft for opening and closing the exhaust valve of the internal combustion engine by setting the advance angle side and the retard angle side in reverse positions.
Besides the lock key
61
assembled on the housing member
30
side in this embodiment of the invention, other lock members, such as lock pin, can be assembled instead of the lock key
61
and the lock member can be assembled on the rotor member
20
side.
The structure in which the lock member (lock key
61
) locks and unlocks by sliding in radial direction is adopted in this embodiment of the invention may be adapted into sliding in axial direction (in this case, it is necessary to dispose the lock recess portion, accommodating the tip portion of the lock member not to move in peripheral direction at initial phase, in axial direction).
The rotor member
20
may be assembled to the crankshaft side rather than the camshaft
10
side, then the housing member
30
is assembled to the camshaft side rather then the crankshaft side in this embodiment of the invention.
The structure of this embodiment of the invention is limited to connecting via the lock key
61
the rear thick plate
34
of the housing member
30
and the rear rotor
23
of the rotor member
20
in the stopper mechanism A and the lock mechanism B. For example, identical effect can be reached by connecting via the lock key
61
the housing member
30
and the camshaft
10
.
It is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is understood that the following claims including all equivalents are intended to define the scope of the invention.
Claims
- 1. A valve timing controller provided on a driving force transmitting system transmitting a driving force to a driven shaft, for opening and closing either an intake valve or an exhaust valve from the drive shaft of an internal combustion engine, comprising:a housing member rotatable in one unit with the drive shaft or the driven shaft; a rotor member provided for relative rotation with a pair of shoe portions provided in the housing member, forming an advance angle fluid chamber and a retard angle fluid chamber in the housing member with a vane portion; a stopper mechanism for defining a initial phase of the housing member and the rotor member; a lock mechanism disposed in the housing member and the rotor member for restricting the relative rotation of the housing member and the rotor member at the initial phase; a hydraulic pressure circuit for controlling the supply and the exhaust of an operation fluid to the advance angle fluid chamber and the retard angle fluid chamber and controlling lock/unlock of the lock mechanism; a lock member slidably assembled with the housing member or the rotor member and a tip portion of said lock member which is always projecting towards the rotor member or the housing member and which moves in a radial direction of the housing member or the rotor member; a free recess portion formed in the rotor member or in the housing member for accommodating a tip portion of the lock member while allowing the relative rotation of the housing member and the rotor member; a stopper surface formed on one end surface in the circumferential direction of the free recess portion for defining the initial phase by the contact with the tip portion of the lock member; a lock recess portion formed continuously along the stopper surface and being capable of accommodating the tip portion of the lock member by restricting the movement thereof in circumferential direction at the initial phase; and a lock spring for biasing the lock member towards the lock recess portion.
- 2. A valve timing controller according to claim 1, wherein a second stopper surface for regulating the maximum rotation amount of the rotor member relative to the housing member is formed on the other end in circumferential direction of the free recess portion opposite to the stopper surface.
- 3. A valve timing controller comprising:a first rotation body for opening and closing at least one of an intake valve and an exhaust valve of an internal combustion engine; a second rotation body for rotating in one unit with a drive shaft of an internal combustion engine and transmitting a driving force from the drive shaft to the first rotation body; and a phase change controlling means for changing the phase of the fist rotation body to an advance angle side or to a retard angle side relative to the second rotation body, including: a stopper mechanism for regulating a rotational amount of the first rotation body to the second rotation body at least to either the advance angle side or the retard angle side; and a lock mechanism for restricting the relative rotation between the first rotation body and the second rotation body, the lock mechanism being operatively positioned in the first and second rotation bodies, wherein the first rotation body and the second rotation body are coaxially arranged and the lock mechanism includes a lock member disposed slidably and rotatably in one unit with one of the first rotation body and the second rotation body and which moves in a radial direction of the first rotation body or the second rotation body; a free recess portion provided on the other one of the first rotation body and the second rotation body for accommodating the lock member while allowing the relative rotation of the first rotation body and the second rotation body; a stopper surface provided on one end surface in peripheral direction of the five recess portion for restricting the rotation of the first rotation body relative to the second rotation body to either the advance angle side or the retard angle side by being connected to the lock member; a lock recess portion provided continuously along the stopper surface for restricting the relative rotation of the first rotation body and the second rotation body; and a biasing means for biasing the lock member towards the lock recess portion.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-270590 |
Sep 1999 |
JP |
|
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4858572 |
Shirai et al. |
Aug 1989 |
A |
6053139 |
Eguchi et al. |
Apr 2000 |
A |
6058897 |
Nakayoshi |
May 2000 |
A |
6079382 |
Schafer et al. |
Jun 2000 |
A |
Foreign Referenced Citations (3)
Number |
Date |
Country |
19755495 |
Jun 1999 |
DE |
9-60508 |
Mar 1997 |
JP |
9-209723 |
Aug 1997 |
JP |