Information
-
Patent Grant
-
6662769
-
Patent Number
6,662,769
-
Date Filed
Friday, March 22, 200222 years ago
-
Date Issued
Tuesday, December 16, 200320 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Denion; Thomas
- Chang; Ching
Agents
- Burns, Doane, Swecker & Mathis, LLP
-
CPC
-
US Classifications
Field of Search
US
- 123 9015
- 123 9016
- 123 9017
- 123 9018
-
International Classifications
-
Abstract
A valve timing control device includes a rotary member rotatably arranged in a torque transmitting route between a crankshaft and a camshaft of an internal combustion engine, a rotational transmitting member rotatable relative to the rotary member, a pressure chamber formed by the rotary member and the rotational transmitting member, a vane provided on the rotary member or the rotational transmitting member to divide the pressure chamber between an advancing chamber and a delaying chamber, a helical spring having a coil portion, a first end portion engaging the rotary member, and a second end portion engaging the rotational transmitting member to urge the rotary member in the advancing direction to expand the advancing chamber. One of the end portions of the helical spring extends on an imagined radial plane arranged in the radial direction of the coil portion.
Description
This application is based on and claims priority under 35 U.S.C. §119 with respect to a Japanese Patent Application 2001-083373 filed on Mar. 22, 2001, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention generally relates to a valve timing control device. More particularly, the present invention pertains to a valve timing control device for controlling the angular phase difference between a crankshaft of a combustion engine and a camshaft of the combustion engine.
BACKGROUND OF THE INVENTION
A known valve timing control device includes a rotary member which is rotatably arranged in a torque transmitting route between a crankshaft of an internal combustion engine and a camshaft of the engine, a rotational transmitting member which rotates relative to the rotary member, a pressure chamber formed by the rotary member and the rotational transmitting member, a vane provided on the rotary member or the rotational transmitting member to divide the pressure chamber into an advancing chamber and a retarding chamber, and a helical spring having a coil portion. A first end portion of the spring engages the rotary member and a second end portion engages the rotational transmitting member, with the spring urging the rotary member in the advancing direction to expand the advancing chamber. A controlling device supplies and discharges fluid to and from the advancing chamber and the retarding chamber to control phase alterations between the rotary member and the rotational transmitting member. An example of a known variable timing device having a construction similar to that described above is disclosed in Japanese Patent Laid-Open Publication No. Heisei 11(1999)-223112.
As a plurality of cams arranged on the camshaft push the valves of the internal combustion engine during engine operation, the rotary member always receives some force. The force rotates the rotational transmitting member in the delayed or retarding direction. The above-described known valve timing control device is provided with the helical spring to rotate the rotary member in the advancing direction so that the helical spring offsets this force. Thus, the response in the advancing direction of the rotary member is improved.
However, as shown in FIGS.
17
(
a
) and
17
(
b
), the structure of the helical spring
270
used in the known valve timing control device includes a coil portion
270
a
, a first hook portion
270
b
and a second hook portion
270
c
. The hook portion
270
b
engages either the rotary member or the rotational transmitting member while the hook portion
270
c
engages the other of the rotary member and the rotational transmitting member. Both of the hook portions
270
b
,
270
c
extend in the axial direction of the coil portion
270
a
. Thus, the total length (LB) of the helical spring
270
is relatively long. Therefore, the overall axial length of the known valve timing control device must be rather long.
SUMMARY OF THE INVENTION
According to one aspect, a valve timing control device includes a rotary member adapted to be rotatably arranged in a torque transmitting route between a crankshaft of an internal combustion engine and a camshaft of the internal combustion engine, a rotational transmitting member rotatable relative to the rotary member, a pressure chamber formed by the rotary member and the rotational transmitting member, a vane provided on the rotary member or the rotational transmitting member dividing the pressure chamber into an advancing chamber and a delaying chamber, and a helical spring which urges the rotary member in the advancing direction to expand the advancing chamber. The helical spring includes a coil portion, a first end portion engaging the rotary member and a second end portion engaging the rotational transmitting member. At least one of the first and second end portions of the helical spring extends on an imagined radial plane arranged in a radial direction of the coil portion.
According to another aspect, a valve timing control device includes a rotary member adapted to be rotatably arranged in a torque transmitting route between a crankshaft of an internal combustion engine and a camshaft of the internal combustion engine, a first annular spring space formed in the rotary member and having an inner circumferential wall and an outer circumferential wall, a rotational transmitting member rotatable relative to the rotary member, a second annular spring space formed in the rotational transmitting member and having an inner circumferential wall and an outer circumferential wall, a pressure chamber formed by the rotary member and the rotational transmitting member, a vane provided on the rotary member or the rotational transmitting member dividing the pressure chamber into an advancing chamber and a delaying chamber, and a helical spring positioned in the first and second annular spring spaces to urge the rotary member in the advancing direction to expand the advancing chamber. The helical spring includes a coil portion, a first end portion and a second end portion, with the first end portion engaging a first groove formed in one of the inner circumferential wall of the rotary member and the outer circumferential wall of the rotary member, and the second end portion engaging a second groove formed in one of the inner circumferential wall of the rotational transmitting member and the outer circumferential wall of the rotational transmitting member.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawing figures in which like reference numerals designate like elements.
FIG.
1
(
a
) is a vertical cross-sectional view of a first embodiment of a valve timing control device in accordance with the prevent invention.
FIGS.
1
(
b
) and
1
(
c
) are enlarged cross-sectional views of a part of FIG.
1
(
a
).
FIG. 2
is a side view of the helical spring used in the valve timing control device shown in FIG.
1
(
a
).
FIG. 3
is an end view of the helical spring shown in FIG.
2
.
FIG. 4
is a sectional view of the valve timing control device when the rotary member is in the most retarded or delayed position relative to the rotational transmitting member.
FIG. 5
is a sectional view of the of the valve timing control device when the rotary member is in the most advanced position relative to the rotational transmitting member.
FIG. 6
is a sectional view of a second embodiment of a valve timing control device when the rotary member is in the most delayed or retarded position relative to the rotational transmitting member.
FIG. 7
is a sectional view of the valve timing control device shown in
FIG. 6
when the rotary member is in the most advanced position relative to the rotational transmitting member.
FIG. 8
is an enlarged end view of the second end portion of the helical spring used in the valve timing control device shown in FIG.
6
.
FIG. 9
is an end view of a helical spring used in a third embodiment of the valve timing control device.
FIG. 10
is a sectional view of the third embodiment of the valve timing control device when the rotary member is in the most delayed or retarded position relative to the rotational transmitting member.
FIG. 11
is a sectional view of the third embodiment of the valve timing control device when the rotary member is in the most advanced position relative to the rotational transmitting member.
FIG. 12
is a sectional view of a fourth embodiment of a valve timing control device when the rotary member is in the most delayed or retarded position relative to the rotational transmitting member.
FIG. 13
is a sectional view of the fourth embodiment of the valve timing control device when the rotary member is in the most advanced position relative to the rotational transmitting member.
FIG. 14
is an end view of the helical spring used in the valve timing control device shown in
FIGS. 12 and 13
.
FIG. 15
is a vertical cross-sectional view of a fifth embodiment of a valve timing control device in accordance with the prevent invention.
FIG. 16
is a vertical cross-sectional view of a sixth embodiment of a valve timing control device in accordance with the prevent invention.
FIG.
17
(
a
) is a side view of a known helical spring.
FIG.
17
(
b
) is an end view of the helical spring shown in FIG.
17
(
a
).
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of a valve timing control device is shown in
FIGS. 1-5
and is applied to an internal combustion engine for vehicles. As shown in
FIG. 1
, the valve timing control device has a rotary member
1
and a rotational transmitting member
2
. The rotary member
1
is arranged in a torque transmitting route between a crankshaft of the internal combustion engine and a camshaft
3
. The rotary member
1
is fixed to the top or end of the camshaft by way of a bolt
30
so that the rotary member
1
rotates together with the camshaft
3
. The rotational transmitting member
2
rotates relative to the rotary member
1
.
The rotational transmitting member
2
includes a housing
20
, a first plate
22
and a second plate
23
. The housing
20
is arranged around the rotary member
1
and has four bores
20
p
for receiving fixing bolts
21
as shown in
FIGS. 4 and 5
. The axial center of the housing
20
is coincident with the axial center of the rotary member
1
. The first plate
22
serves as a front plate and is arranged on one surface of the housing
20
, and the second plate
23
serves as a rear plate and is arranged on the other surface of the housing
20
. Each of the fixing bolts
21
has a screw portion
21
c
to fix the housing
20
, the first plate
22
and the second plate
23
together.
The outer surface of the housing
20
is provided with a timing sprocket
23
a
to connect with a gear
25
of the crankshaft via a transmitting means
24
, for example a timing chain or a timing belt. When the gear
25
of the crankshaft of the internal combustion engine rotates, the housing
20
with the first and second plates
22
,
23
rotates via the transmitting means
24
and the timing sprocket
23
a
. At that time, the housing
20
causes the rotary member
1
with the camshaft
3
to rotate so that the camshaft
3
pushes down the valves of the internal combustion engine so as to open the valves.
As shown in
FIG. 4
, the housing
20
has four projections
4
, each of which extends toward the center of the housing
20
. A sliding surface
48
is formed on the tip of the projections
4
to slide around or along the circumference of the rotary member
1
. Each projection
4
has circumferentially spaced end portions
44
s
,
44
r
. A pressure chamber
40
is defined by each of the openings between the projections
44
s
,
44
r
. Thus, in this embodiment, there are four pressure chambers
40
which are distributed in the circumferential direction of the housing
20
. Each pressure chamber
40
is encircled or surrounded by the outer circumference of the rotary member
1
, the housing
20
, the first plate
22
and the second plate
23
.
Distributed circumferentially about the housing
20
are four vane grooves
41
, each of which faces toward the pressure chamber
40
and receives a vane
5
. The vanes
5
are arranged on imaginary lines P
4
passing through the axial center of the rotary member
1
and arranged so that adjacent ones are at right angles to each other. Each vane
5
divides the respective pressure chamber
40
into a delaying or retarding chamber
42
and an advancing chamber
43
. The delaying chambers
42
are connected with pressure passages. The advancing chambers
43
are connected with other pressure passages. The pressure passages are located in the rotary member
1
.
One of the projections
4
has a locking mechanism
6
. The locking member
6
prohibits the rotary member
1
from rotating in the advanced direction relative to the rotational transmitting member
2
when the rotary member
1
is the most delayed or retarded position. The locking mechanism
6
is comprised of a locking body
60
and a spring
61
for urging the locking body
60
toward the axial center of the rotary member
1
(i.e., the direction indicated by the arrow K
1
in FIG.
4
). Here, the locking body
60
is arranged on an imaginary line P
5
passing through the axial center of the rotary member
1
.
When the internal combustion engine is stopped, the rotary member
1
rotates in the delayed direction (i.e., the direction indicated by the arrow S
1
in
FIG. 4
) and reaches the most delayed position shown in FIG.
4
. Only the vane
5
a
of the plural vanes
5
contacts the end portion
44
r
of the projection
4
. Thus, the contact between the vane
5
a
and the end portion
44
r
is as a stopper for preventing the rotary member
1
from further rotating in the delayed direction relative to the rotational transmitting member
2
. When the rotary member
1
is in the most delayed or retarded position, the locking body
60
of the locking mechanism
6
moves into a locking bore
12
of the rotary member
1
by the urging force of the spring
61
so that the rotary member
1
can not rotate in any direction. This condition is desirable for starting the internal combustion engine. As the fluid pressure is not stable at the starting of the internal combustion engine, the locking mechanism
6
maintains the rotational phase between the rotary member
1
and the rotational transmitting member
2
.
After a short period has passed from the starting of the internal combustion engine, the fluid pressure becomes stable. The fluid pressure moves to the top or end of the locking body
60
via a fluid pressure passage formed in the rotary member
1
. The fluid pressure pushes the end or top of the locking body
60
in order to move the locking body
60
in the K
2
direction of FIG.
5
. Thus, the locking mechanism
6
is released so that the rotary member
1
rotates relative to the rotational transmitting member
2
. Therefore, the rotational phase of the camshaft
3
can rotate relative to that of the crankshaft of the internal combustion engine in the S
1
or S
2
direction of
FIGS. 4 and 5
.
When the fluid pressure in the advanced chamber
43
is discharged via an advancing fluid supplying passage and the fluid pressure is supplied into the delayed chamber
42
via a delaying fluid supplying passage, the rotary member
1
with the vanes
5
rotates in the delayed or retarded direction (i.e., the S
1
direction of
FIGS. 4 and 5
) relative to the housing
20
.
On the other hand, when the fluid pressure in the delayed chamber
42
is discharged via the delaying fluid supplying passage and the fluid pressure is supplied into the advanced chamber
43
via the advancing fluid supplying passage, the rotary member
1
with the vanes
5
rotates in the advanced direction (i.e., the S
2
direction of
FIGS. 4 and 5
) relative to the housing
20
.
FIG. 5
illustrates the most advancing condition where the rotary member
1
with the vanes
5
is furthest rotated relative to the housing
20
. As shown in
FIG. 5
, one vane
5
b
of the plural vanes
5
contacts the end portion
44
s
of one of the projections
4
. Thus, the contact between the vane
5
b
and the end portion
44
s
serves as another stopper for preventing the rotary member
1
from rotating further in the advanced direction relative to the rotational transmitting member
2
.
The term “the delayed direction” means that the opening and closing timing of the valves of the internal combustion engine is late while the term “the advanced direction” means that the opening and closing timing of the valves of the internal combustion engine is early. When the rotary member
1
with the vanes
5
rotates in the delayed direction, the capacity of the delayed chamber
42
increases and that of the advanced chamber
43
decreases. When the rotary member
1
with the vanes
5
rotates in the advanced direction, the capacity of the delayed chamber
42
decreases and that of the advanced chamber
43
increases. Therefore, the timing valve control device controls the opening and closing timing of the valves so as to control the engine performance.
As shown in
FIG. 1
, a spring space
80
, which is ring-shaped or annular, is arranged between the first plate
22
of the rotational transmitting member
2
and the rotary member
1
. The spring space
80
consists of a first spring space
81
and a second spring space
82
. The first spring space
81
is formed on the end surface of the rotary member
1
in the axial direction. The second space
82
is formed on the surface of the first plate
22
which faces the first spring space
81
. The first spring space
81
has an inner circumferential wall
81
a, an outer circumferential wall
81
b
and a first groove
1
m
. The first groove
1
m
receives a first end portion
27
b
of a helical spring
27
. The first groove
1
m
extends in the radial direction of the rotary member
1
and is formed in the outer circumferential wall
81
b
as shown in FIG.
1
(
b
). The second spring space
82
has an inner circumferential wall
82
a
, an outer circumferential wall
82
b
and a second groove
22
m
. The second groove
22
m
receives a second end portion
27
c
of the helical spring
27
. The second groove
22
m
extends in the radial direction of the first plate
22
and is formed in the outer circumferential wall
82
b
as shown in FIG.
1
(
c
).
The helical spring
27
is made of metal and consists of a torsion spring or coil portion
27
a
having the first end portion
27
b
and the second end portion
27
c
as shown in
FIGS. 2 and 3
. As shown in
FIG. 1
, the helical spring
27
is arranged in the spring space
80
. Specifically, the torsion spring or coil portion
27
a
is arranged in the axial direction of the rotary member
1
. As shown in
FIG. 3
, the end portions
27
b
,
27
c
of the helical spring
27
extend on an imagined radial plane arranged in the radial direction of the coil portion
27
a
and extend in the radial direction of the coil portion
27
a
. As illustrated in
FIG. 3
, the extended length of the first end portion
27
b
(the distance that the first end portion
27
b
extends outwardly from the outer periphery of the coil portion
27
a
) is designated as E
1
, and the extended length of the second end portion
27
c
(the distance that the second end portion
27
c
extends outwardly from the outer periphery of the coil portion
27
a
) is designated as E
2
.
As shown in FIGS.
1
(
a
),
1
(
b
) and
1
(
c
), the first end portion
27
b
of the helical spring
27
is engaged with the rotary member
1
and the second end portion
27
c
of the helical spring
27
is engaged with the first plate
22
of the rotational transmitting member
2
. The helical spring
27
urges the rotary member
1
in the advanced direction (i.e., the 'S
2
” direction in
FIGS. 4 and 5
) relative to the housing
20
. The purpose of the urging force of the helical spring
27
is to offset the above-mentioned force which occurs during the internal combustion engine driving (i.e., the force received by the rotary member and associated with the cams pushing the valves of the internal combustion engine during engine operation).
As shown in FIGS.
1
(
a
),
1
(
b
) and
1
(
c
), the width of the first spring space
81
which is formed between the inner circumferential wall
81
a
and the outer circumferential wall
81
b
is larger than the thickness of the coil portion
27
a
. There are thus plenty of gaps
91
between the torsion spring
27
a
and the walls
81
a
,
81
b
in the first spring space
81
. Further, in much the same way, there are plenty of gaps
92
between the coil portion
27
a
, the inner circumferential wall
81
a
and the outer circumferential wall
81
b
in the second spring space
82
. When the rotary member
1
rotates in any direction relative to the housing
20
of the rotational transmitting member
2
, the coil portion
27
a
is twisted. However, the gaps
91
,
92
inhibit or prevent the coil portion
27
a
from touching the circumferential walls
81
a
,
81
b
,
82
a
,
82
b
so as to obtain the expected urging force.
According to the embodiment described above, both end portions
27
b
,
27
c
extend in the radial direction of the torsion spring
27
a
as shown in FIGS.
1
(
b
),
1
(
c
),
2
and
3
. The axial length LA of the helical spring
27
is the same as the length of the coil portion
27
a
. Therefore, the total axial length of the valve timing control device becomes relatively small. In addition, even if the relative rotation between the rotary member
1
and the rotational transmitting member makes the diameter of the coil portion
27
a
small, the engagement portion of the end portions
27
b
,
27
c
are secured. Therefore, the engagement condition of the helical spring
27
between the rotary member
1
and the rotational transmitting member
2
is maintained.
FIGS. 6-8
illustrate a second embodiment of the valve timing control device. In this second embodiment, the parts of the valve timing control device that are the same as those in the first embodiment are identified with the same reference numerals as those used in
FIGS. 1-5
. Having described such features above, a detailed description of such features will not be repeated.
As shown in
FIGS. 6 and 7
, an enlarged projection
95
is provided on the inner circumferential wall
81
a
. The outwardly directed enlarged projection
95
extends in the axial direction of the rotary member
1
. As shown in
FIG. 8
, another outwardly directed enlarged projection
96
is provided on the inner circumferential wall
82
a
. This enlarged projection
96
extends in the same direction as the enlarged projection
95
. The enlarged projections
95
,
96
are adapted to engage portions of the coil portion
27
a
adjacent the two end portions
27
b
,
27
c
as shown in
FIGS. 6-8
. The enlarged projections
95
,
96
thus inhibit or prevent the inner surface of the coil portion
27
a
from coming into contact with the inner circumferential walls
81
a
,
82
b
. Here, if the rotary member
1
and the first plate
22
are made of sintering material or casting material, forming the enlarged projections
95
,
96
is relatively easy. Even if the relative rotation between the rotary member
1
and the rotational transmitting member
2
causes the diameter of the coil portion
27
a
to become small, the inner surface of the coil portion
27
a
contacts substantially only the enlarged projections
95
,
96
. Therefore, this second embodiment provides not only the advantages described above in connection with the first embodiment, but also the additional advantage that the frictional resistance between the helical spring
27
and the inner circumferential walls
81
a
,
82
a
do not have to be enlarged.
FIGS. 9-11
illustrate a third embodiment of the valve timing control device. The parts of the valve timing control device that are the same as those in the first embodiment are identified with the same reference numerals as those used in
FIGS. 1-5
. Having described such features above, a detailed description of such features will not be repeated.
In this third embodiment, the helical spring
27
has two inwardly directed curved portions
97
,
98
. The curved portion
97
is arranged at the one end, which is the end wire rod, of the coil portion
27
a
, near the base of the end portion
27
b
(i.e., where the end portion
27
b
meets the coil portion
27
a
). The curve portion
98
is arranged at the other end wire rod of the coil portion
27
a
, near the base of the end portion
27
c
(i.e., where the end portion
27
c
meets the coil portion
27
a
). Even if the relative rotation between the rotary member
1
and the rotational transmitting member
2
causes the diameter of the coil portion
27
a
to become small, the inner surface of the coil portion
27
a
substantially does not contact the inner circumferential walls
81
a
,
82
a
. Rather, only the tops of the curve portions
97
,
98
contact the circumferential walls
81
a
,
82
a
. This third embodiment provides advantages similar to those described above in connection with the second embodiment.
FIGS. 12-14
illustrate a fourth embodiment of the valve timing control device. The parts of the valve timing control device that are the same as those in the first embodiment are identified with the same reference numerals as those used in
FIGS. 1-5
. Having described such features above, a detailed description of such features will not be repeated.
As shown in
FIG. 14
, the curvature (radius of curvature) of both end wire rods of the coil portion
27
a
are smaller than the curvature (radius of curvature) of the wire rod forming the other portion (middle portion) of the torsion spring
27
a
. Thus, the coil portion
27
a
of the fourth embodiment has two smaller diameter portions
100
,
102
. The smaller diameter portion
100
is arranged on one end wire rod of the coil portion
27
a
, near the base of the end portion
27
b
(i.e., where the end portion
27
b
meets the coil portion
27
a
). The other smaller diameter portion
102
is arranged on the other end wire rod of the coil portion
27
a
, near the base of the end portion
27
c
(i.e., where the end portion
27
c
meets the coil portion
27
a
). Even if the relative rotation between the rotary member
1
and the rotational transmitting member
2
causes the diameter of the coil portion
27
a
to become small, the inner surface of the coil portion
27
a
does not contact the inner circumferential walls
81
a
,
82
a
. Rather, only the tops of the small diameter portions
100
,
102
contact the walls
81
a
and
82
a
. Therefore, this fourth embodiment provides similar advantages to those associated with the second and third embodiments.
In the above-described embodiments, four pressure chambers
40
and vanes
5
are provided. However, the number of vanes and pressure chambers is not limited in this regard. Also, as described above, the rotational transmitting member
2
is rotated by the crankshaft and the rotary member
1
is attached to the cam shaft
3
. However, it is also possible for the rotary member
1
to be rotated by the crankshaft while the housing member
20
of the rotational transmitting member
2
is integrally attached on the cam shaft
3
. Further, the vanes
5
can be integrally mounted on the rotary member
1
.
Additionally, in the above-described embodiments, the vanes
5
are supported on the rotary member
1
. However, it is also possible to support the vanes
5
on the housing
20
of the rotational transmitting member
2
.
In the embodiments described above, the locking body
60
provides a lock between the rotary member
1
and the housing
20
when the rotary member
1
rotates relative to the housing
20
and is at the most delayed position. However, it is possible that the locking body
60
provides a lock when the rotary member
1
is positioned at an intermediate portion between the most delayed position and the most advanced position. It is also possible that the locking body
60
provides the lock when the rotary member
1
is at the most advanced position. This type of valve timing control device is normally used for the camshaft
3
for operating exhaust valves.
Regarding the lengths of the first and second end portions
27
b
,
27
c
, end portions
27
b
,
27
c
of the same length are desirable. However, it is also possible for one length to be longer than the other one. Of course, it is also acceptable that only one end portion
27
b
,
27
c
extends on the radial surface of the coil portion
27
a
. In this case, it is preferred that the second end portion
27
c
extend on the radial surface of the coil portion
27
a
because the total axial length of the valve timing control device can be made relatively small.
In addition, in the embodiments described above, the end portions
27
b
,
27
c
extend in the radial direction of the coil portion
27
a
. However, the precise angle of the end portions
27
b
,
27
c
is not important, but both of the end portions
27
b
,
27
c
are on the same surface, which is the axial direction of the coil portion
27
a
. Thus, it is possible that the angle between the end portions
27
b
,
27
c
and the end of the torsion spring is not a right angle. It is also possible for the end portion
27
b
and/or
27
c
to be extended in the inner direction of the torsion spring
27
a.
FIG. 15
illustrates a fifth embodiment of the valve timing control device. The parts of the valve timing control device that are the same as those in the first embodiment are identified with the same reference numerals as those used in
FIGS. 1-5
. Having described such features above, a detailed description of such features will not be repeated.
As shown in
FIG. 15
, a pulley
104
connected with the gear
25
of the crankshaft via the transmitting means
24
is fixed on the second plate
23
of the rotational transmitting member
2
by way of bolts
137
. The bolts
137
are bored through or positioned at the outer end portion
23
a
of the second plate
23
.
A front cover
134
is made from a sheet of pressed iron plate. The front cover
134
has a bottom or end wall
134
a
, a circumferential wall
134
b
and an outer circumferential portion
134
c
. The bottom wall
134
faces the first plate
22
, the circumferential wall
134
b
faces the housing
20
and the outer circumferential portion
134
c
faces the outer end portion
23
a
of the second plate
23
. The outer circumferential portion
134
c
, the outer end portion
23
a
and the pulley
104
are integrally fixed by the bolts
137
.
The surface of the outer end portion
23
a
of the second plate
23
which faces the outer circumferential portion
134
c
is provided with a U-shaped groove
23
b
. The groove
23
b
is a circular groove extending around the housing
20
. A seal ring
138
is positioned in the groove
23
b
to prevent oil from leaking.
The bottom or end wall
134
a
of the front cover
134
has a hole or through opening
134
d
for screwing or tightening the bolt
30
. The hole
134
d
is closed liquidly (in a liquid-tight manner) by a lid
35
. Thus, the front cover
134
covers the rotational transmitting member
2
for protecting the transmitting means
24
, for example the timing belt, against the pressure fluid. In addition, it is not necessary to secure any space for inserting the seal ring
138
. Therefore, the axial length of the rotational transmitting member
2
is relatively small.
FIG. 16
illustrates a sixth embodiment of the valve timing control device according to the present invention. The parts of the valve timing control device that are the same as those in the first embodiment are identified with the same reference numerals as those used in
FIGS. 1-5
. Having described such features above, a detailed description of such features will not be repeated.
As shown in
FIG. 16
, a bolt receiving bore of the second plate
23
is a bottomed bore or blind bore
23
c
. Thus, the sealing characteristic around the fixing bolt
21
are improved.
The principles, preferred embodiments and modes 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.
Claims
- 1. A valve timing control device comprising:a rotary member adapted to be rotatably arranged in a torque transmitting route between a crankshaft of an internal combustion engine and a camshaft of the internal combustion engine; a rotational transmitting member rotatable relative to the rotary member; a pressure chamber formed by the rotary member and the rotational transmitting member; a vane provided on the rotary member or the rotational transmitting member dividing the pressure chamber into an advancing chamber and a delaying chamber; a helical spring which urges the rotary member in the advancing direction to expand the advancing chamber, the helical spring having a coil portion, a first end portion engaging the rotary member and a second end portion engaging the rotational transmitting member; and at least one of the first and second end portions of the helical spring extending on an imagined radial plane arranged in a radial direction of the coil portion.
- 2. The valve timing control device according to claim 1, wherein the at least one of the first and second end portions of the helical spring extends in the radial direction of the coil portion.
- 3. The valve timing control device according to claim 2, wherein the at least one of the first and second end portions of the helical spring extends outwardly from the coil portion.
- 4. The valve timing control device according to claim 3, wherein both the first and second end portions of the helical spring extend in the radial direction of the coil portion.
- 5. The valve timing control device according to claim 1, wherein both the first and second end portions of the helical spring extend in the radial direction of the coil portion.
- 6. The valve timing control device according to claim 1, wherein both the first and second end portions of the helical spring extend outwardly in the radial direction of the coil portion.
- 7. The valve timing control device according to claim 1, wherein the helical spring is positioned in a spring space surrounded by an inner circumferential wall and an outer circumferential wall, and including at least one axially extending and outwardly directed projection formed on the inner circumferential wall to engage a portion of the coil portion adjacent one of the first and second end portions.
- 8. The valve timing control device according to claim 1, wherein the helical spring is positioned in a spring space surrounded by an inner circumferential wall and an outer circumferential wall, and including a pair of axially extending and outwardly directed projections formed on the inner circumferential wall to engage a portion of the coil portion adjacent each of the first and second end portions.
- 9. The valve timing control device according to claim 1, wherein the coil portion of the helical spring is provided with an inwardly directed curved portion at a position where the coil portion meets one of the first and second end portions.
- 10. The valve timing control device according to claim 1, wherein the coil portion of the helical spring is provided with a pair of inwardly directed curved portions each located at a position where the coil portion meets one of the first and second end portions.
- 11. The valve timing control device according to claim 1, wherein an end of the coil portion which meets with one of the first and second end portions of the helical spring possesses a smaller diameter than a remaining part of the coil portion.
- 12. The valve timing control device according to claim 1, wherein ends of the coil portion which meet with the first and second end portions of the helical spring possess a smaller diameter than a remaining part of the coil portion.
- 13. A valve timing control device comprising:a rotary member adapted to be rotatably arranged in a torque transmitting route between a crankshaft of an internal combustion engine and a camshaft of the internal combustion engine; a first annular spring space formed in the rotary member, the first annular spring space having an annular inner circumferential wall and an annular outer circumferential wall; a rotational transmitting member rotatable relative to the rotary member; a second annular spring space formed in the rotational transmitting member, the second annular spring space having an annular inner circumferential wall and an annular outer circumferential wall; a pressure chamber formed by the rotary member and the rotational transmitting member; a vane provided on the rotary member or the rotational transmitting member dividing the pressure chamber into an advancing chamber and a delaying chamber; a helical spring positioned in the first and second annular spring spaces to urge the rotary member in the advancing direction to expand the advancing chamber, the helical spring having a coil portion, a first end portion and a second end portion; the first end portion of the helical spring engaging a first groove formed in one of the inner circumferential wall of the rotary member and the outer circumferential wall of the rotary member; and the second end portion of the helical spring engaging a second groove formed in one of the inner circumferential wall of the rotational transmitting member and the outer circumferential wall of the rotational transmitting member.
- 14. The valve timing control device according to claim 13, wherein both of the first and second end portions of the helical spring extend in the radial outward direction of the coil portion.
- 15. The valve timing control device according to claim 13, wherein at least one of the first and second end portions of the helical spring extends outwardly from the coil portion.
- 16. The valve timing control device according to claim 13, wherein the first groove is formed in the outer circumferential wall of the rotary member and the second groove is formed in the outer circumferential wall of the rotational transmitting member.
- 17. The valve timing control device according to claim 13, including an axially extending and outwardly directed projection formed on the inner circumferential wall of the rotary member to engage a portion of the coil portion adjacent the first end portion, and an axially extending and outwardly directed projection formed on the inner circumferential wall of the rotational transmitting member to engage a portion of the coil portion adjacent the second end portion.
- 18. The valve timing control device according to claim 13, wherein the coil portion of the helical spring is provided with a pair of inwardly directed curved portions each located at a position where the coil portion meets one of the first and second end portions.
- 19. The valve timing control device according to claim 13, wherein ends of the coil portion which meet with the first and second end portions of the helical spring possess a smaller diameter than a remaining part of the coil portion.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2001-083373 |
Mar 2001 |
JP |
|
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A |
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A |
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B1 |
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Number |
Date |
Country |
10-30411 |
Feb 1998 |
JP |
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Aug 1999 |
JP |
2000-97006 |
Apr 2000 |
JP |