Valve timing control device

Details Valve timing control device Valve timing control device

2002-04-15

2003-12-23

Denion, Thomas (Department: 3748)

Internal-combustion engines

Poppet valve operating mechanism

With means for varying timing

C123S090150, C123S090370

Reexamination Certificate

active

06666180

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a valve timing control device (hereafter, referred as a device) altering timing for the closing and opening of an exhaust valve or intake valve of an internal-combustion engine (hereafter, referred as an engine) with reference to any operating conditions.
2. Description of the Related Art
FIG. 1
is a lateral cross sectional view of an internal configuration of a related valve timing control device.
FIG. 2
is a longitudinal cross sectional view of the internal configuration of the related valve timing control device shown in FIG.
1
. In the drawings, a reference numeral
1
denotes a first rotor, which is coupled to a crankshaft (not shown) as an output shaft of the engine by way of chains (not shown) and is rotatable in synchronization with the crankshaft (not shown). The first rotor
1
is integrated with a sprocket
2
, a case
3
and a cover
4
using a threaded member
5
such as bolts. The sprocket
2
is rotated integrally with the crankshaft (not shown). The case
3
has a plurality of shoes
3
a
projected inwardly from an inner periphery of the case
3
to constitute a plurality of hydraulic chambers. The hydraulic chambers are blocked with the cover
4
.
A rotor (second rotor)
6
is rotated relative to the first rotor
1
and is disposed in the case
3
. The rotor
6
is integrally fixed on one end of an intake camshaft (hereafter, referred simply as a camshaft
7
), which relates to timing for the closing and opening of an intake valve (not shown), or an exhaust camshaft (hereafter, referred simply as a camshaft
7
), which relates to timing for the closing and opening of an exhaust valve (not shown), using a threaded member (not shown) such as bolts. The rotor
6
includes a boss section
6
a
having a bearing section
6
b
, which allows insertion of the one end of the camshaft
7
, and a plurality of vanes
6
c
projected outwardly from an outer periphery of the boss section
6
a
in a radial direction of the boss section
6
a
to partition the hydraulic chambers, which are constituted by the shoes
3
a
of the case
3
, into an advanced side hydraulic chamber
8
and a retarded side hydraulic chamber
9
. The advanced side hydraulic chamber
8
means a hydraulic chamber to which a hydraulic pressure is supplied in order to move relatively the rotor
6
, which is located at a reference position with respect to the case
3
shown in
FIG. 1
, toward the advanced side (in a direction of arrow X
1
) when the first rotor
1
including the case
3
rotates in the direction of arrow X
1
shown in FIG.
1
. On the other hand, the retarded side hydraulic chamber
9
means a hydraulic chamber to which a hydraulic pressure is supplied in order to move relatively the rotor
6
, which is located at the reference position with respect to the case
3
shown in
FIG. 1
, toward the retarded side (in a direction of arrow X
2
) when the first rotor
1
including the case
3
rotates in the direction of arrow X
1
shown in FIG.
1
.
A first oil path
10
is arranged in the sprocket
2
and supplies a hydraulic pressure derived from an oil pump (not shown) to the advanced side hydraulic chamber
8
through an oil control valve (not shown) and an advanced side oil path (not shown) in the camshaft
7
. A second oil path
11
is arranged in the rotor
6
and supplies a hydraulic pressure derived from the oil pump (not shown) and so on to the retarded side hydraulic chamber
9
through a retarded side oil path (not shown) in the camshaft
7
.
An accommodation hole
13
accommodating a locking pin
12
, which controls a relative rotation of the case
3
and the rotor
6
, is so arranged at one of the shoes
3
a
of the case
3
as to pierce the case
3
in the radial direction.
Here, when the engine is started without producing a hydraulic pressure in the device, the rotor
6
vibrates in rotational directions due to a load of a cam (not shown) which is fixed integrally at the camshaft
7
. Due to the vibration, contact and separation between the rotor
6
and the case
3
are repeated, and accordingly a beat noise occurs. The locking pin
12
prevents the occurrence of such a beat noise. The locking pin
12
includes a frontal minor-diameter section
12
a
allowing insertion into an engagement hole described later, a rear major-diameter section
12
b
having an outer diameter larger than the frontal minor-diameter section
12
a
, and a recess
12
c
formed at a rear bottom of the rear major-diameter section
12
b.
The accommodation hole
13
includes a minor-diameter hole section
13
a
accommodating the frontal minor-diameter section
12
a
of the locking pin
12
, and a major-diameter hole section
12
b
with an inner diameter larger than that of the minor-diameter hole section
13
a
, the section
12
b
accommodating the rear major-diameter section
12
b
of the locking pin
12
. A passage-selectable valve
16
is arranged at a position, which is adjacent to the shoe
3
a
equipped with the accommodation hole
13
, of an end of the sprocket
2
close to the case
3
. The passage-selectable valve
16
selects the higher hydraulic pressure of the two different pressures in the advanced and retarded hydraulic chambers
8
and
9
, and supplies the selected pressure to a hydraulic chamber
15
defined between a frontal end face of the rear major-diameter section
12
b
of the locking pin
12
and a frontal end face of the major-diameter hole section
13
b
of the accommodation hole
13
by way of a hydraulic pressure supply passage
14
to unlock an engagement (hereafter, referred as a locking relation) of the locking pin
12
with the engagement hole described later. An advanced side hydraulic partitioned passage
17
communicates between the passage-selectable valve
16
and the advanced side hydraulic chamber
8
, and a retarded side hydraulic partitioned passage
18
communicates between the passage-selectable valve
16
and the retarded side hydraulic chamber
9
.
A prevention holder
21
is press-fitted in an outer periphery (outermost section of the device) of the major-diameter section
13
b
of the accommodation hole
13
. The prevention holder
21
prevents the locking pin
12
and a coil spring
20
biasing the locking pin
12
against the rotor
6
at all times from being ejected out of the outermost section of the device. The prevention holder
21
is fixed at an outer periphery of the major-diameter section
13
b
of the accommodation hole
13
using a prevention pin
22
. A discharge hole
23
is formed at a central section of the prevention holder
21
and discharges a backward pressure, which is produced in the accommodation hole
13
when the locking pin
12
moves back, to outside of the device. Moreover, the coil spring
20
is arranged between the recess
12
c
of the locking pin
12
and the prevention holder
21
.
On the other hand, an engagement hole
24
is formed inwardly at a position, where the engagement hole
24
allows insertion of the frontal minor-diameter section
12
a
of the locking pin
12
when the rotor
6
is located at the reference position (most retarded position in
FIG. 1
) with respect to the case
3
, of an outer periphery of the boss section
6
a
of the rotor
6
in the radial direction.
Seal means
25
are disposed at frontal ends of the respective vanes
6
c
of the rotor
6
, and make contact with an inner periphery of the case
3
corresponding to each vane
6
c
to prevent oil leaks through a boundary between the advanced and retarded hydraulic chambers
8
and
9
.
Incidentally, with a general device, speaking of the related device, a seal means like the seal mean above is often disposed at each of frontal ends (section A in
FIG. 1
) of each shoe
3
a
, which is located inside each of frontal ends of the respective vanes
6
c
. With one device, the seal means disposed at the section A positioned inside the device are however decommissioned in order to reduce cost of parts and so on and to simplify the structure of device as in the case of t

Affiliated with

Also associated with

Rating

Valve timing control device does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Valve timing control device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Valve timing control device will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3168198